《Redis 设计与实现》图片集¶
你好， 欢迎光临《Redis 设计与实现》图片集！
这里列出了 《Redis 设计与实现》 一书包含的绝大多数图片， 并且所有图片的源码都可以在 github.com/huangz1990/redisbook1e-gallery 项目的相应文件中找到 （源码使用 dot 语言编写，由 Graphviz 生成）。
你可以在你的博客文章、笔记甚至是演讲稿里面使用这些图片， 或者通过阅读图片的源码来学习如何使用 dot 语言和 Graphviz 。
所有图片和源码都采用 CC BY-NC 4.0 协议 进行许可， 你只要说明这些材料来源于《Redis 设计与实现》（或者添加一个指向 RedisBook.com 的链接）， 就可以以非商业目的随意地使用这些材料。
如果有任何疑问， 请通过 huangz.me 上面列出的联系方式来联系我。
![digraph {
label = "\n 图 2-1 SDS 示例";
rankdir = LR;
node [shape = record];
//
sdshdr [label = "sdshdr | free \n 0 | len \n 5 | <buf> buf"];
buf [label = "{ 'R' | 'e' | 'd' | 'i' | 's' | '\\0' }"];
//
sdshdr:buf -> buf;
}](_images/graphviz-72760f6945c3742eca0df91a91cc379168eda82d.png)
![digraph {
label = "\n 图 2-2 带有未使用空间的 SDS 示例";
rankdir = LR;
node [shape = record];
//
sdshdr [label = "sdshdr | free \n 5 | len \n 5 | <buf> buf"];
buf [label = "{ 'R' | 'e' | 'd' | 'i' | 's' | '\\0' | | | | | }"];
//
sdshdr:buf -> buf;
}](_images/graphviz-5fccf03155ec72c7fb2573bed9d53bf8f8fb7878.png)
![digraph {
rankdir = TB;
node [shape = record];
str [label = " <1> 'R' | <2> 'e' | <3> 'd' | <4> 'i' | <5> 's' | <6> '\\0' "];
node [shape = plaintext];
p1 [label = "len = 1"];
p1 -> str:1;
}](_images/graphviz-15702f3018be5f9c38705fe1a3c3179cfc7ce208.png)
![digraph {
rankdir = TB;
node [shape = record];
str [label = " <1> 'R' | <2> 'e' | <3> 'd' | <4> 'i' | <5> 's' | <6> '\\0' "];
node [shape = plaintext];
p2 [label = "len = 2"];
p2 -> str:2;
}](_images/graphviz-11db45788777fdf62308ab859e5e4418276616b1.png)
![digraph {
rankdir = TB;
node [shape = record];
str [label = " <1> 'R' | <2> 'e' | <3> 'd' | <4> 'i' | <5> 's' | <6> '\\0' "];
node [shape = plaintext];
p3 [label = "len = 3"];
p3 -> str:3;
}](_images/graphviz-22f91c392200e20da51ad61306765bee1d874a13.png)
![digraph {
rankdir = TB;
node [shape = record];
str [label = " <1> 'R' | <2> 'e' | <3> 'd' | <4> 'i' | <5> 's' | <6> '\\0' "];
node [shape = plaintext];
p4 [label = "len = 4"];
p4 -> str:4;
}](_images/graphviz-ff4aa6ea06fabe2bdf8f26325bca6a02fa480da8.png)
![digraph {
rankdir = TB;
node [shape = record];
str [label = " <1> 'R' | <2> 'e' | <3> 'd' | <4> 'i' | <5> 's' | <6> '\\0' "];
node [shape = plaintext];
p5 [label = "len = 5"];
p5 -> str:5;
}](_images/graphviz-59da530d8d0f16ce3eff95e285460b9ea5a0f389.png)
![digraph {
label = "\n 图 2-4 计算 C 字符串长度的过程";
rankdir = TB;
node [shape = record];
str [label = " <1> 'R' | <2> 'e' | <3> 'd' | <4> 'i' | <5> 's' | <6> '\\0' "];
node [shape = plaintext];
p6 [label = "发现空字符 \n 停止计数 \n 字符串的长度为 5 字节"];
p6 -> str:6;
}](_images/graphviz-e505478b940695671030146e66d6b3b292e7ae8c.png)
![digraph {
label = "\n 图 3-1 由多个 listNode 组成的双端链表"
rankdir = LR;
node [shape = record];
//
more_prev [label = "...", shape = plaintext];
x [label = "<head> listNode | value \n ..."];
y [label = "<head> listNode | value \n ..."];
z [label = "<head> listNode | value \n ..."];
more_next [label = "...", shape = plaintext];
//
more_prev -> x [label = "next"];
x -> more_prev [label = "prev"];
x -> y [label = "next"];
y -> x [label = "prev"];
y -> z [label = "next"];
z -> y [label = "prev"];
z -> more_next [label = "next"];
more_next -> z [label = "prev"];
}](_images/graphviz-167adfc2e52e078d4c0e3c8a9eddec54551602fb.png)
![digraph {
label = "\n 图 3-2 由 list 结构和 listNode 结构组成的链表"
rankdir = LR;
node [shape = record];
//
list [label = "list | <head> head | <tail> tail | <len> len \n 3 | <dup> dup | <free> free | <match> match ", width = 2.0];
more_prev [label = "NULL", shape = plaintext];
x [label = "<head> listNode | value \n ..."];
y [label = "<head> listNode | value \n ..."];
z [label = "<head> listNode | value \n ..."];
more_next [label = "NULL", shape = plaintext];
dup [label = "...", shape = plaintext];
free [label = "...", shape = plaintext];
match [label = "...", shape = plaintext];
//
list:head -> x;
list:tail -> z;
list:dup -> dup;
list:free -> free;
list:match -> match;
x -> y;
y -> x;
y -> z;
z -> y;
//
more_prev -> x [dir = back];
z -> more_next;
}](_images/graphviz-5f4d8b6177061ac52d0ae05ef357fceb52e9cb90.png)
第 4 章：字典¶
一个空的哈希表。
![digraph {
label = "\n 图 4-1 一个空的哈希表";
rankdir = LR;
//
node [shape = record];
dictht [label = " <head> dictht | <table> table | <size> size \n 4 | <sizemask> sizemask \n 3 | <used> used \n 0"];
table [label = " <head> dictEntry*[4] | <0> 0 | <1> 1 | <2> 2 | <3> 3 "];
//
node [shape = plaintext, label = "NULL"];
null0;
null1;
null2;
null3;
//
dictht:table -> table:head;
table:0 -> null0;
table:1 -> null1;
table:2 -> null2;
table:3 -> null3;
}](_images/graphviz-bd3eecd927a4d8fc33b4a1c7f5957c52d67c5021.png)
使用链地址法解决冲突的哈希表。
![digraph {
label = "\n 图 4-2 连接在一起的键 k1 和键 k0";
rankdir = LR;
//
node [shape = record];
dictht [label = " <head> dictht | <table> table | <size> size \n 4 | <sizemask> sizemask \n 3 | <used> used \n 2"];
table [label = " <head> dictEntry*[4] | <0> 0 | <1> 1 | <2> 2 | <3> 3 "];
dictEntry0 [label = " <head> dictEntry | { k0 | v0 }"];
dictEntry1 [label = " <head> dictEntry | { k1 | v1 }"];
//
node [shape = plaintext, label = "NULL"];
null0;
null1;
null2;
null3;
//
dictht:table -> table:head;
table:0 -> null0;
table:1 -> null1;
table:2 -> dictEntry1;
dictEntry1 -> dictEntry0 -> null2 [label = "next"];
table:3 -> null3;
}](_images/graphviz-d2641d962325fd58bf15d9fffb4208f70251a999.png)
普通状态下（未在进行 rehash）的字典。
![digraph {
label = "\n 图 4-3 普通状态下的字典";
rankdir = LR;
//
node [shape = record];
dict [label = " <head> dict | type | privdata | <ht> ht | rehashidx \n -1 "];
dictht0 [label = " <head> dictht | <table> table | <size> size \n 4 | <sizemask> sizemask \n 3 | <used> used \n 2"];
dictht1 [label = " <head> dictht | <table> table | <size> size \n 0 | <sizemask> sizemask \n 0 | <used> used \n 0"];
table0 [label = " <head> dictEntry*[4] | <0> 0 | <1> 1 | <2> 2 | <3> 3 "];
table1 [label = "NULL", shape = plaintext];
dictEntry0 [label = " <head> dictEntry | { k0 | v0 }"];
dictEntry1 [label = " <head> dictEntry | { k1 | v1 }"];
//
node [shape = plaintext, label = "NULL"];
null0;
null1;
null2;
null3;
//
dict:ht -> dictht0:head [label = "ht[0]"];
dict:ht -> dictht1:head [label = "ht[1]"];
dictht0:table -> table0:head;
dictht1:table -> table1;
table0:0 -> null0;
table0:1 -> dictEntry0:head -> null1;
table0:2 -> null2;
table0:3 -> dictEntry1:head -> null3;
}](_images/graphviz-e73003b166b90094c8c4b7abbc8d59f691f91e27.png)
包含了键值对的字典。
![digraph {
label = "\n 图 4-5 添加键值对 k0 和 v0 之后的字典";
rankdir = LR;
//
node [shape = record];
dict [label = " <head> dict | type | privdata | <ht> ht | rehashidx \n -1 "];
dictht0 [label = " <head> dictht | <table> table | <size> size \n 4 | <sizemask> sizemask \n 3 | <used> used \n 1"];
dictht1 [label = "...", shape = plaintext];
table0 [label = " <head> dictEntry*[4] | <0> 0 | <1> 1 | <2> 2 | <3> 3 "];
//table1 [label = "NULL", shape = plaintext];
dictEntry [label = " <head> dictEntry | { k0 | v0 } "];
//
node [shape = plaintext, label = "NULL"];
null0;
null1;
null2;
null3;
//
dict:ht -> dictht0:head [label = "ht[0]"];
dict:ht -> dictht1:head [label = "ht[1]"];
dictht0:table -> table0:head;
//dictht1:table -> table1;
table0:0 -> dictEntry:head -> null0;
table0:1 -> null1;
table0:2 -> null2;
table0:3 -> null3;
}](_images/graphviz-2369cb08288f5e59548355042c4c40cc4339e339.png)
字典的 rehash 过程。
![digraph {
label = "\n 图 4-8 执行 rehash 之前的字典";
rankdir = LR;
node [shape = record];
// 字典
dict [label = " <head> dict | type | privdata | <ht> ht | rehashidx \n -1 "];
// 哈希表
dictht0 [label = " <head> dictht | <table> table | <size> size \n 4 | <sizemask> sizemask \n 3 | <used> used \n 4"];
dictht1 [label = " <head> dictht | <table> table | <size> size \n 0 | <sizemask> sizemask \n 0 | <used> used \n 0"];
table0 [label = " <head> dictEntry*[4] | <0> 0 | <1> 1 | <2> 2 | <3> 3 "];
table1 [label = "NULL", shape = plaintext];
// 哈希表节点
kv0 [label = " <head> dictEntry | { k0 | v0 } "];
kv1 [label = " <head> dictEntry | { k1 | v1 } "];
kv2 [label = " <head> dictEntry | { k2 | v2 } "];
kv3 [label = " <head> dictEntry | { k3 | v3 } "];
//
node [shape = plaintext, label = "NULL"];
null0;
null1;
null2;
null3;
//
dict:ht -> dictht0:head [label = "ht[0]"];
dict:ht -> dictht1:head [label = "ht[1]"];
dictht0:table -> table0:head;
dictht1:table -> table1;
table0:0 -> kv2:head -> null0;
table0:1 -> kv0:head -> null1;
table0:2 -> kv3:head -> null2;
table0:3 -> kv1:head -> null3;
}](_images/graphviz-93608325578e8e45848938ef420115bf2227639e.png)
![digraph {
label = "\n 图 4-9 为字典的 ht[1] 哈希表分配空间";
rankdir = LR;
node [shape = record];
// 字典
dict [label = " <head> dict | type | privdata | <ht> ht | rehashidx \n -1 "];
// 哈希表
dictht0 [label = " <head> dictht | <table> table | <size> size \n 4 | <sizemask> sizemask \n 3 | <used> used \n 4"];
dictht1 [label = " <head> dictht | <table> table | <size> size \n 8 | <sizemask> sizemask \n 7 | <used> used \n 0"];
table0 [label = " <head> dictEntry*[4] | <0> 0 | <1> 1 | <2> 2 | <3> 3 "];
table1 [label = " <head> dictEntry*[8] | <0> 0 | <1> 1 | <2> 2 | ... | <7> 7 "];
// 哈希表节点
kv0 [label = " <head> dictEntry | { k0 | v0 } "];
kv1 [label = " <head> dictEntry | { k1 | v1 } "];
kv2 [label = " <head> dictEntry | { k2 | v2 } "];
kv3 [label = " <head> dictEntry | { k3 | v3 } "];
//
node [shape = plaintext, label = "NULL"];
//
dict:ht -> dictht0:head [label = "ht[0]"];
dict:ht -> dictht1:head [label = "ht[1]"];
dictht0:table -> table0:head;
dictht1:table -> table1:head;
table0:0 -> kv2:head -> null0;
table0:1 -> kv0:head -> null1;
table0:2 -> kv3:head -> null2;
table0:3 -> kv1:head -> null3;
table1:0 -> null10;
table1:1 -> null11;
table1:2 -> null12;
table1:7 -> null17;
}](_images/graphviz-b68acb4d868ec7d79a44935ce08a159746ca58da.png)
![digraph {
label = "\n 图 4-10 ht[0] 的所有键值对都已经被迁移到 ht[1]";
rankdir = LR;
node [shape = record];
// 字典
dict [label = " <head> dict | type | privdata | <ht> ht | rehashidx \n -1 "];
// 哈希表
dictht0 [label = " <head> dictht | <table> table | <size> size \n 4 | <sizemask> sizemask \n 3 | <used> used \n 0"];
dictht1 [label = " <head> dictht | <table> table | <size> size \n 8 | <sizemask> sizemask \n 7 | <used> used \n 4"];
table0 [label = " <head> dictEntry*[4] | <0> 0 | <1> 1 | <2> 2 | <3> 3 "];
table1 [label = " <head> dictEntry*[8] | ... | <1> 1 | ... | <4> 4 | <5> 5 | ... | <7> 7 "];
// 哈希表节点
kv0 [label = " <head> dictEntry | { k0 | v0 } "];
kv1 [label = " <head> dictEntry | { k1 | v1 } "];
kv2 [label = " <head> dictEntry | { k2 | v2 } "];
kv3 [label = " <head> dictEntry | { k3 | v3 } "];
//
node [shape = plaintext, label = "NULL"];
//
dict:ht -> dictht0:head [label = "ht[0]"];
dict:ht -> dictht1:head [label = "ht[1]"];
dictht0:table -> table0:head;
dictht1:table -> table1:head;
table0:0 -> null0;
table0:1 -> null1;
table0:2 -> null2;
table0:3 -> null3;
table1:1 -> kv3:head -> null11;
table1:4 -> kv2:head -> null14;
table1:5 -> kv0:head -> null15;
table1:7 -> kv1:head -> null17;
}](_images/graphviz-92dc47e4329eabae941cddfd727b736ef738e8cf.png)
![digraph {
label = "\n 图 4-11 完成 rehash 之后的字典";
rankdir = LR;
node [shape = record];
// 字典
dict [label = " <head> dict | type | privdata | <ht> ht | rehashidx \n -1 "];
// 哈希表
dictht0 [label = " <head> dictht | <table> table | <size> size \n 8 | <sizemask> sizemask \n 7 | <used> used \n 4"];
dictht1 [label = " <head> dictht | <table> table | <size> size \n 0 | <sizemask> sizemask \n 0 | <used> used \n 0"];
table0 [label = " <head> dictEntry*[8] | ... | <1> 1 | ... | <4> 4 | <5> 5 | ... | <7> 7 "];
table1 [label = "NULL", shape = plaintext];
// 哈希表节点
kv0 [label = " <head> dictEntry | { k0 | v0 } "];
kv1 [label = " <head> dictEntry | { k1 | v1 } "];
kv2 [label = " <head> dictEntry | { k2 | v2 } "];
kv3 [label = " <head> dictEntry | { k3 | v3 } "];
//
node [shape = plaintext, label = "NULL"];
//
dict:ht -> dictht0:head [label = "ht[0]"];
dict:ht -> dictht1:head [label = "ht[1]"];
dictht0:table -> table0:head;
dictht1:table -> table1;
table0:1 -> kv3:head -> null11;
table0:4 -> kv2:head -> null14;
table0:5 -> kv0:head -> null15;
table0:7 -> kv1:head -> null17;
}](_images/graphviz-fa28d986a72f1f48b83c7f959ea217b1f9527d3c.png)
字典的渐进式 rehash 过程。
![digraph {
label = "\n 图 4-12 准备开始 rehash";
rankdir = LR;
node [shape = record];
// 字典
dict [label = " <head> dict | type | privdata | <ht> ht | rehashidx \n -1 "];
// 哈希表
dictht0 [label = " <head> dictht | <table> table | <size> size \n 4 | <sizemask> sizemask \n 3 | <used> used \n 4"];
dictht1 [label = " <head> dictht | <table> table | <size> size \n 8 | <sizemask> sizemask \n 7 | <used> used \n 0"];
table0 [label = " <head> dictEntry*[4] | <0> 0 | <1> 1 | <2> 2 | <3> 3 "];
table1 [label = " <head> dictEntry*[8] | <0> 0 | <1> 1 | <2> 2 | ... | <7> 7 "];
// 哈希表节点
kv0 [label = " <head> dictEntry | { k0 | v0 } "];
kv1 [label = " <head> dictEntry | { k1 | v1 } "];
kv2 [label = " <head> dictEntry | { k2 | v2 } "];
kv3 [label = " <head> dictEntry | { k3 | v3 } "];
//
node [shape = plaintext, label = "NULL"];
//
dict:ht -> dictht0:head [label = "ht[0]"];
dict:ht -> dictht1:head [label = "ht[1]"];
dictht0:table -> table0:head;
dictht1:table -> table1:head;
table0:0 -> kv2:head -> null0;
table0:1 -> kv0:head -> null1;
table0:2 -> kv3:head -> null2;
table0:3 -> kv1:head -> null3;
table1:0 -> null10;
table1:1 -> null11;
table1:2 -> null12;
table1:7 -> null17;
}](_images/graphviz-4c43eaf38cbca10d8d368a5144db6f3c69ab3d84.png)
![digraph {
label = "\n 图 4-13 rehash 索引 0 上的键值对";
rankdir = LR;
node [shape = record];
// 字典
dict [label = " <head> dict | type | privdata | <ht> ht | rehashidx \n 0 "];
// 哈希表
dictht0 [label = " <head> dictht | <table> table | <size> size \n 4 | <sizemask> sizemask \n 3 | <used> used \n 3"];
dictht1 [label = " <head> dictht | <table> table | <size> size \n 8 | <sizemask> sizemask \n 7 | <used> used \n 1"];
table0 [label = " <head> dictEntry*[4] | <0> 0 | <1> 1 | <2> 2 | <3> 3 "];
table1 [label = " <head> dictEntry*[8] | ... | <4> 4 | ... "];
// 哈希表节点
kv0 [label = " <head> dictEntry | { k0 | v0 } "];
kv1 [label = " <head> dictEntry | { k1 | v1 } "];
kv2 [label = " <head> dictEntry | { k2 | v2 } "];
kv3 [label = " <head> dictEntry | { k3 | v3 } "];
//
node [shape = plaintext, label = "NULL"];
//
dict:ht -> dictht0:head [label = "ht[0]"];
dict:ht -> dictht1:head [label = "ht[1]"];
dictht0:table -> table0:head;
dictht1:table -> table1:head;
table0:0 -> null0;
table0:1 -> kv0:head -> null1;
table0:2 -> kv3:head -> null2;
table0:3 -> kv1:head -> null3;
table1:4 -> kv2:head -> null14
}](_images/graphviz-b91705b0d7a6c7fd5e37332a930534e0e136ae73.png)
![digraph {
label = "\n 图 4-14 rehash 索引 1 上的键值对";
rankdir = LR;
node [shape = record];
// 字典
dict [label = " <head> dict | type | privdata | <ht> ht | rehashidx \n 1 "];
// 哈希表
dictht0 [label = " <head> dictht | <table> table | <size> size \n 4 | <sizemask> sizemask \n 3 | <used> used \n 2"];
dictht1 [label = " <head> dictht | <table> table | <size> size \n 8 | <sizemask> sizemask \n 7 | <used> used \n 2"];
table0 [label = " <head> dictEntry*[4] | <0> 0 | <1> 1 | <2> 2 | <3> 3 "];
table1 [label = " <head> dictEntry*[8] | ... | <4> 4 | <5> 5 | ... "];
// 哈希表节点
kv0 [label = " <head> dictEntry | { k0 | v0 } "];
kv1 [label = " <head> dictEntry | { k1 | v1 } "];
kv2 [label = " <head> dictEntry | { k2 | v2 } "];
kv3 [label = " <head> dictEntry | { k3 | v3 } "];
//
node [shape = plaintext, label = "NULL"];
//
dict:ht -> dictht0:head [label = "ht[0]"];
dict:ht -> dictht1:head [label = "ht[1]"];
dictht0:table -> table0:head;
dictht1:table -> table1:head;
table0:0 -> null0;
table0:1 -> null1;
table0:2 -> kv3:head -> null2;
table0:3 -> kv1:head -> null3;
table1:4 -> kv2:head -> null14
table1:5 -> kv0:head -> null15;
}](_images/graphviz-9e2996e6ca9665776062470cdac346e8fc255374.png)
![digraph {
label = "\n 图 4-15 rehash 索引 2 上的键值对";
rankdir = LR;
node [shape = record];
// 字典
dict [label = " <head> dict | type | privdata | <ht> ht | rehashidx \n 2 "];
// 哈希表
dictht0 [label = " <head> dictht | <table> table | <size> size \n 4 | <sizemask> sizemask \n 3 | <used> used \n 1"];
dictht1 [label = " <head> dictht | <table> table | <size> size \n 8 | <sizemask> sizemask \n 7 | <used> used \n 3"];
table0 [label = " <head> dictEntry*[4] | <0> 0 | <1> 1 | <2> 2 | <3> 3 "];
table1 [label = " <head> dictEntry*[8] | ... | <1> 1 | ... | <4> 4 | <5> 5 | ... "];
// 哈希表节点
kv0 [label = " <head> dictEntry | { k0 | v0 } "];
kv1 [label = " <head> dictEntry | { k1 | v1 } "];
kv2 [label = " <head> dictEntry | { k2 | v2 } "];
kv3 [label = " <head> dictEntry | { k3 | v3 } "];
//
node [shape = plaintext, label = "NULL"];
//
dict:ht -> dictht0:head [label = "ht[0]"];
dict:ht -> dictht1:head [label = "ht[1]"];
dictht0:table -> table0:head;
dictht1:table -> table1:head;
table0:0 -> null0;
table0:1 -> null1;
table0:2 -> null2;
table0:3 -> kv1:head -> null3;
table1:1 -> kv3:head -> null11;
table1:4 -> kv2:head -> null14
table1:5 -> kv0:head -> null15;
}](_images/graphviz-c871b5de1a7910aea237ca9dc86508b48da94769.png)
![digraph {
label = "\n 图 4-16 rehash 索引 3 上的键值对";
rankdir = LR;
node [shape = record];
// 字典
dict [label = " <head> dict | type | privdata | <ht> ht | rehashidx \n 3 "];
// 哈希表
dictht0 [label = " <head> dictht | <table> table | <size> size \n 4 | <sizemask> sizemask \n 3 | <used> used \n 0"];
dictht1 [label = " <head> dictht | <table> table | <size> size \n 8 | <sizemask> sizemask \n 7 | <used> used \n 4"];
table0 [label = " <head> dictEntry*[4] | <0> 0 | <1> 1 | <2> 2 | <3> 3 "];
table1 [label = " <head> dictEntry*[8] | ... | <1> 1 | ... | <4> 4 | <5> 5 | ... | <7> 7 "];
// 哈希表节点
kv0 [label = " <head> dictEntry | { k0 | v0 } "];
kv1 [label = " <head> dictEntry | { k1 | v1 } "];
kv2 [label = " <head> dictEntry | { k2 | v2 } "];
kv3 [label = " <head> dictEntry | { k3 | v3 } "];
//
node [shape = plaintext, label = "NULL"];
//
dict:ht -> dictht0:head [label = "ht[0]"];
dict:ht -> dictht1:head [label = "ht[1]"];
dictht0:table -> table0:head;
dictht1:table -> table1:head;
table0:0 -> null0;
table0:1 -> null1;
table0:2 -> null2;
table0:3 -> null3;
table1:1 -> kv3:head -> null11;
table1:4 -> kv2:head -> null14
table1:5 -> kv0:head -> null15;
table1:7 -> kv1:head -> null17;
}](_images/graphviz-3b31e4e08cc3e212f986039eb08ae77224cdeec9.png)
![digraph {
label = "\n 图 4-17 rehash 执行完毕";
rankdir = LR;
node [shape = record];
// 字典
dict [label = " <head> dict | type | privdata | <ht> ht | rehashidx \n -1 "];
// 哈希表
dictht0 [label = " <head> dictht | <table> table | <size> size \n 8 | <sizemask> sizemask \n 7 | <used> used \n 4"];
dictht1 [label = " <head> dictht | <table> table | <size> size \n 0 | <sizemask> sizemask \n 0 | <used> used \n 0"];
table0 [label = " <head> dictEntry*[8] | ... | <1> 1 | ... | <4> 4 | <5> 5 | ... | <7> 7 "];
table1 [label = "NULL", shape = plaintext];
// 哈希表节点
kv0 [label = " <head> dictEntry | { k0 | v0 } "];
kv1 [label = " <head> dictEntry | { k1 | v1 } "];
kv2 [label = " <head> dictEntry | { k2 | v2 } "];
kv3 [label = " <head> dictEntry | { k3 | v3 } "];
//
node [shape = plaintext, label = "NULL"];
//
dict:ht -> dictht0:head [label = "ht[0]"];
dict:ht -> dictht1:head [label = "ht[1]"];
dictht0:table -> table0:head;
dictht1:table -> table1;
table0:1 -> kv3:head -> null11;
table0:4 -> kv2:head -> null14;
table0:5 -> kv0:head -> null15;
table0:7 -> kv1:head -> null17;
}](_images/graphviz-86f810ac65c4e6ee58b17105dfeaa06973d8dd16.png)
![digraph {
rankdir = LR;
node [shape = record, width = "0.5"];
//
l [label = " <header> header | <tail> tail | level \n 5 | length \n 3 "];
subgraph cluster_nodes {
style = invisible;
header [label = " <l32> L32 | ... | <l5> L5 | <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 "];
bw_null [label = "NULL", shape = plaintext];
level_null [label = "NULL", shape = plaintext];
A [label = " <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 | <backward> BW | 1.0 | o1 "];
B [label = " <l2> L2 | <l1> L1 | <backward> BW | 2.0 | o2 "];
C [label = " <l5> L5 | <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 | <backward> BW | 3.0 | o3 "];
}
subgraph cluster_nulls {
style = invisible;
n1 [label = "NULL", shape = plaintext];
n2 [label = "NULL", shape = plaintext];
n3 [label = "NULL", shape = plaintext];
n4 [label = "NULL", shape = plaintext];
n5 [label = "NULL", shape = plaintext];
}
//
l:header -> header;
l:tail -> C;
header:l32 -> level_null [label = "0"];
header:l5 -> C:l5 [label = "3"];
header:l4 -> A:l4 [label = "1"];
header:l3 -> A:l3 [label = "1"];
header:l2 -> A:l2 [label = "1"];
header:l1 -> A:l1 [label = "1"];
A:l4 -> C:l4 [label = "2"];
A:l3 -> C:l3 [label = "2"];
A:l2 -> B:l2 [label = "1"];
A:l1 -> B:l1 [label = "1"];
B:l2 -> C:l2 [label = "1"];
B:l1 -> C:l1 [label = "1"];
C:l5 -> n5 [label = "0"];
C:l4 -> n4 [label = "0"];
C:l3 -> n3 [label = "0"];
C:l2 -> n2 [label = "0"];
C:l1 -> n1 [label = "0"];
bw_null -> A:backward -> B:backward -> C:backward [dir = back];
label = "\n 图 5-1 一个跳跃表";
}](_images/graphviz-8fc5de396a5b52c3d0b1991a1e09558ad055dd86.png)
![digraph {
rankdir = LR;
node [shape = record, width = "0.5"];
//
l [label = " <header> header | <tail> tail | level \n 5 | length \n 3 "];
subgraph cluster_nodes {
style = invisible;
header [label = " <l32> L32 | ... | <l5> L5 | <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 "];
bw_null [label = "NULL", shape = plaintext];
level_null [label = "NULL", shape = plaintext];
A [label = " <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 | <backward> BW | 1.0 | o1 "];
B [label = " <l2> L2 | <l1> L1 | <backward> BW | 2.0 | o2 "];
C [label = " <l5> L5 | <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 | <backward> BW | 3.0 | o3 "];
}
subgraph cluster_nulls {
style = invisible;
n1 [label = "NULL", shape = plaintext];
n2 [label = "NULL", shape = plaintext];
n3 [label = "NULL", shape = plaintext];
n4 [label = "NULL", shape = plaintext];
n5 [label = "NULL", shape = plaintext];
}
//
l:header -> header [style = dashed];
l:tail -> C;
header:l32 -> level_null [label = "0"];
header:l5 -> C:l5 [label = "3"];
header:l4 -> A:l4 [label = "1", style = dashed];
header:l3 -> A:l3 [label = "1"];
header:l2 -> A:l2 [label = "1"];
header:l1 -> A:l1 [label = "1"];
A:l4 -> C:l4 [label = "2"];
A:l3 -> C:l3 [label = "2"];
A:l2 -> B:l2 [label = "1", style = dashed];
A:l1 -> B:l1 [label = "1"];
B:l2 -> C:l2 [label = "1", style = dashed];
B:l1 -> C:l1 [label = "1"];
C:l5 -> n5 [label = "0"];
C:l4 -> n4 [label = "0"];
C:l3 -> n3 [label = "0"];
C:l2 -> n2 [label = "0", style = dashed];
C:l1 -> n1 [label = "0"];
bw_null -> A:backward -> B:backward -> C:backward [dir = back];
label = "\n 图 5-3 遍历整个跳跃表";
}](_images/graphviz-e252c0a9575f171b9721162311df23889699cac9.png)
![digraph {
rankdir = LR;
node [shape = record, width = "0.5"];
//
l [label = " <header> header | <tail> tail | level \n 5 | length \n 3 "];
subgraph cluster_nodes {
style = invisible;
header [label = " <l32> L32 | ... | <l5> L5 | <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 "];
bw_null [label = "NULL", shape = plaintext];
level_null [label = "NULL", shape = plaintext];
A [label = " <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 | <backward> BW | 1.0 | o1 "];
B [label = " <l2> L2 | <l1> L1 | <backward> BW | 2.0 | o2 "];
C [label = " <l5> L5 | <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 | <backward> BW | 3.0 | o3 "];
}
subgraph cluster_nulls {
style = invisible;
n1 [label = "NULL", shape = plaintext];
n2 [label = "NULL", shape = plaintext];
n3 [label = "NULL", shape = plaintext];
n4 [label = "NULL", shape = plaintext];
n5 [label = "NULL", shape = plaintext];
}
//
l:header -> header;
l:tail -> C [style = dashed];
header:l32 -> level_null [label = "0"];
header:l5 -> C:l5 [label = "3"];
header:l4 -> A:l4 [label = "1"];
header:l3 -> A:l3 [label = "1"];
header:l2 -> A:l2 [label = "1"];
header:l1 -> A:l1 [label = "1"];
A:l4 -> C:l4 [label = "2"];
A:l3 -> C:l3 [label = "2"];
A:l2 -> B:l2 [label = "1"];
A:l1 -> B:l1 [label = "1"];
B:l2 -> C:l2 [label = "1"];
B:l1 -> C:l1 [label = "1"];
C:l5 -> n5 [label = "0"];
C:l4 -> n4 [label = "0"];
C:l3 -> n3 [label = "0"];
C:l2 -> n2 [label = "0"];
C:l1 -> n1 [label = "0"];
bw_null -> A:backward -> B:backward -> C:backward [dir = back, style = dashed];
label = "\n 图 5-6 从表尾向表头方向遍历跳跃表";
}](_images/graphviz-35029fe9a9dbed7001f6fee063c0b376bca6e54d.png)
第 6 章：整数集合¶
一个整数集合示例，包含五个 int16_t 类型的整数值。
![digraph {
label = "\n 图 6-1 一个包含五个 int16_t 类型整数值的整数集合";
rankdir = LR;
node [shape = record];
intset [label = " intset | encoding \n INTSET_ENC_INT16 | length \n 5 | <contents> contents "];
//contents [label = " { { 0 位至 15 位 | <arrow> -6370 } | { 16 位至 31 位 | -5 } | { 32 位至 47 位 | 18 } | { 48 至 63 位 | 233 } | { 64 位至 79 位 | 14632 } } "];
//intset:contents -> contents:arrow;
contents [label = " { -6370 | -5 | 18 | 233 | 14632 } "];
intset:contents -> contents;
}](_images/graphviz-acf7fe010d7b09c5d2500c72eb555863e67ad74f.png)
另一个整数集合示例，包含四个 int64_t 类型的整数值。
![digraph {
label = "\n 图 6-2 一个包含四个 int64_t 类型整数值的整数集合";
rankdir = LR;
node [shape = record];
intset [label = " intset | encoding \n INTSET_ENC_INT64 | length \n 4 | <contents> contents "];
contents [label = " { -2675256175807981027 | 1 | 3 | 5 } "];
intset:contents -> contents:arrow;
}](_images/graphviz-878c08b90e7bbd02863d3e5cad116b36785ea30e.png)
当向一个包含三个 int16_t 类型的值的整数集合添加一个 int32_t 类型的值时，
整数集合的扩展和转换过程。
![digraph {
label = "\n 图 6-4 contents 数组的各个元素，以及它们所在的位";
node [shape = record];
contents [label = " { 位 | 元素 } | { 0 至 15 位 | 1 } | { 16 至 31 位 | 2 } | { 32 至 47 位 | 3 } "];
}](_images/graphviz-eac3e19de3f8dd9c40f2302c7b2d10e73983cd5c.png)
![digraph {
label = "\n 图 6-5 进行空间重分配之后的数组";
node [shape = record];
contents [label = " { 位 | 元素 } | { 0 至 15 位 | 1 } | { 16 至 31 位 | 2 } | { 32 至 47 位 | 3 } | { 48 至 127 位 | （新分配空间）} "];
}](_images/graphviz-63f486a40c957eb449a5836555915601a1be61d6.png)
![digraph {
label = "\n 图 6-6 对元素 3 进行类型转换，并保存在适当的位上";
node [shape = record];
contents [label = " { 位 | 元素 } | { 0 至 15 位 | 1 } | { 16 至 31 位 | 2 } | { 32 至 47 位 | <old> 3 } | { 48 至 63 位 | （新分配空间） } | { 64 位至 95 位 | <new> 3 } | { 96 位至 127 位 | （新分配空间）} "];
contents:old -> contents:new [label = "从 int16_t 类型转换为 int32_t 类型"];
}](_images/graphviz-b8d54b0b6f077fd7a618a9fc198350cb3301fe8a.png)
![digraph {
label = "\n 图 6-7 对元素 2 进行类型转换，并保存在适当的位上";
node [shape = record];
contents [label = " { 位 | 元素 } | { 0 至 15 位 | 1 } | { 16 至 31 位 | <old> 2 } | { 32 至 63 位 | <new> 2 } | { 64 位至 95 位 | 3 } | { 96 位至 127 位 | （新分配空间）} "];
contents:old -> contents:new [label = "从 int16_t 类型转换为 int32_t 类型"];
}](_images/graphviz-851e799be7671b59d22c1360c757f70871b1460a.png)
![digraph {
label = "\n 图 6-8 对元素 1 进行类型转换，并保存在适当的位上";
node [shape = record];
contents [label = " { 位 | 元素 } | { 0 至 31 位 | <old> 1 } | { 32 至 63 位 | 2 } | { 64 位至 95 位 | 3 } | { 96 位至 127 位 | （新分配空间）} "];
//contents:old -> contents:new [label = "从 int16_t 类型转换为 int32_t 类型"];
contents:old -> contents:old [label = "从 int16_t 类型转换为 int32_t 类型"];
}](_images/graphviz-a6e1fc86a05aa7dab4284dbdb027cedb96a5259a.png)
![digraph {
label = "\n 图 6-9 添加 65535 到数组";
rankdir = BT;
node [shape = record];
set [label = "添加新元素", shape = plaintext];
contents [label = " { 位 | 元素 } | { 0 至 31 位 | 1 } | { 32 至 63 位 | 2 } | { 64 位至 95 位 | 3 } | { 96 位至 127 位 | <new> 65535 } "];
set -> contents:new;
}](_images/graphviz-c0a4fd52c53de90a8b70888f89c7b39df564fc6b.png)
第 7 章：压缩列表¶
压缩列表的各个部分
![digraph {
label = "\n 图 7-1 压缩列表的各个组成部分";
node [shape = record];
ziplist [label = " zlbytes | zltail | zllen | entry1 | entry2 | ... | entryN | zlend "];
}](_images/graphviz-fe42f343a3f32f477efb5e895da547d476a7c97d.png)
一个包含三个节点的压缩列表示例。
![digraph {
rankdir = BT;
label = "\n 图 7-2 包含三个节点的压缩列表";
node [shape = record];
ziplist [label = " <zlbytes> zlbytes \n 0x50 | zltail \n 0x3c | zllen \n 0x3 | entry1 | entry2 | <entry3> entry3 | zlend \n 0xFF "];
node [shape = plaintext];
p [label = "p"];
p -> ziplist:zlbytes;
tail [label = "p + 60"];
tail -> ziplist:entry3;
}](_images/graphviz-071fe5086440a360087904af9a5f78e8e02c2d8d.png)
一个包含五个节点的压缩列表示例。
![digraph {
label = "\n 图 7-3 包含五个节点的压缩列表";
rankdir = BT;
node [shape = record];
ziplist [label = " <zlbytes> zlbytes \n 0xd2 | zltail \n 0xb3 | zllen \n 0x5 | entry1 | entry2 | entry3 | entry4 | <entry5> entry5 | zlend \n 0xFF "];
node [shape = plaintext];
p [label = "p"];
p -> ziplist:zlbytes;
tail [label = "p + 179"];
tail -> ziplist:entry5;
}](_images/graphviz-a3654fb3d550f27965699e3049654cc59924f99c.png)
压缩列表节点的各个组成部分。
![digraph {
label = "\n 图 7-4 压缩列表节点的各个组成部分";
node [shape = record];
n [label = " previous_entry_length | encoding | content "];
}](_images/graphviz-cc6b40e182bfc142c12ac0518819a2d949eafa4a.png)
压缩列表节点的 previous_entry_length 属性示例。
![digraph {
label = "\n 图 7-5 当前节点的前一节点的长度为 5 字节";
node [shape = record];
n [label = " previous_entry_length \n 0x05 | encoding \n ... | content \n ... "];
}](_images/graphviz-bcf2d2cccedc9fa6a4d11e2331cda9d9d18e3ce7.png)
使用压缩列表节点的 previous_entry_length 属性遍历整个压缩列表的过程。
![digraph {
rankdir = BT;
node [shape = record];
entry1 [label = " zlbytes | zltail | zllen | <e1> entry1 | <e2> entry2 | <e3> entry3 | <e4> entry4 | zlend "];
node [shape = plaintext];
p1 -> entry1:e4;
}](_images/graphviz-cc50542b1187b200cb89ed4b37695dcbf9db4e1f.png)
![digraph {
rankdir = BT;
node [shape = record];
entry2 [label = " zlbytes | zltail | zllen | <e1> entry1 | <e2> entry2 | <e3> entry3 | <e4> entry4 | zlend "];
node [shape = plaintext];
p2 [label = "p2 = p1 - entry4.previous_entry_length"];
p2 -> entry2:e3;
}](_images/graphviz-e9faeda02f5f8d08f81e08e2feb125a565df5e91.png)
![digraph {
rankdir = BT;
node [shape = record];
entry3 [label = " zlbytes | zltail | zllen | <e1> entry1 | <e2> entry2 | <e3> entry3 | <e4> entry4 | zlend "];
node [shape = plaintext];
p3 [label = "p3 = p2 - entry3.previous_entry_length"];
p3 -> entry3:e2;
}](_images/graphviz-6c4fdcd56711eb2abd46e671f30269cb52411e71.png)
![digraph {
label = "\n 图 7-8 一个从表尾向表头遍历的例子";
rankdir = BT;
node [shape = record];
entry4 [label = " zlbytes | zltail | zllen | <e1> entry1 | <e2> entry2 | <e3> entry3 | <e4> entry4 | zlend "];
node [shape = plaintext];
p4 [label = "p4 = p3 - entry2.previous_entry_length"];
p4 -> entry4:e1;
}](_images/graphviz-85d5042240608e1f9833b78027ab9de6790392a7.png)
一个保存着 "hello world" 字符串的压缩列表节点示例。
![digraph {
label = "\n 图 7-9 保存着字节数组 \"hello world\" 的节点";
node [shape = record];
entry [label = " previous_entry_length \n ... | encoding \n 00001011 | content \n \"hello world\" "];
}](_images/graphviz-556d0890afb2675ce91d30a1b2cb2a429d0c217f.png)
一个保存着整数 10086 的压缩列表节点示例。
![digraph {
label = "\n 图 7-10 保存着整数值 10086 的节点";
node [shape = record];
entry [label = " previous_entry_length \n ... | encoding \n 11000000 | content \n 10086 "];
}](_images/graphviz-cfb376f8015f3af9f59acd30dc71a35e90c6d763.png)
向压缩列表添加新节点并引发连锁更新的过程。
![digraph {
label = "\n 图 7-11 包含节点 e1 至 eN 的压缩列表";
node [shape = record];
ziplist [label = " zlbytes| zltail | zllen | e1 | e2 | e3 | ... | eN | zlend "];
}](_images/graphviz-734bbf5a1fa692f6d7a69edbbcf49bf337c1a061.png)
![digraph {
label = "\n 图 7-12 添加新节点到压缩列表";
rankdir = BT;
node [shape = record];
ziplist [label = " zlbytes | zltail | zllen | <new> new | e1 | e2 | e3 | ... | eN | zlend "];
p [label = "添加新节点", shape = plaintext];
p -> ziplist:new;
}](_images/graphviz-a403378a625e791d8af8bb60c7ebfce466233eee.png)
![digraph {
rankdir = BT;
node [shape = record];
ziplist [label = " zlbytes | zltail | zllen | <new> new | <e1> e1 | <e2> e2 | <e3> e3 | ... | <en> eN | zlend "];
p [label = "扩展 e1 \n并引发对 e2 的扩展", shape = plaintext];
p -> ziplist:e1;
}](_images/graphviz-7d01d41bb23475dbd0e3d7d8a1e3f4c9c300ee25.png)
![digraph {
rankdir = BT;
node [shape = record];
ziplist [label = " zlbytes | zltail | zllen | <new> new | <e1> e1 | <e2> e2 | <e3> e3 | ... | <en> eN | zlend "];
p [label = "扩展 e2 \n并引发对 e3 的扩展", shape = plaintext];
p -> ziplist:e2;
}](_images/graphviz-7cf42c1bb5595457d19f0d8ff709d65c49ba8278.png)
![digraph {
rankdir = BT;
node [shape = record];
ziplist [label = " zlbytes | zltail | zllen | <new> new | <e1> e1 | <e2> e2 | <e3> e3 | ... | <en> eN | zlend "];
p [label = "扩展 e3 \n并引发对 e4 的扩展", shape = plaintext];
p -> ziplist:e3;
}](_images/graphviz-f7d3e0af6174a2845a1d31773b96b5912de73b3f.png)
![digraph {
rankdir = BT;
node [shape = record];
ziplist [label = " zlbytes | zltail | zllen | <new> new | <e1> e1 | <e2> e2 | <e3> e3 | <more> ... | <en> eN | zlend "];
p [label = "一直扩展下去……", shape = plaintext];
p -> ziplist:more;
}](_images/graphviz-b51a8a86bd07d77656f0a2e6be414473f7cabeeb.png)
![digraph {
label = "\n 图 7-13 连锁更新过程";
rankdir = BT;
node [shape = record];
ziplist [label = " zlbytes | zltail | zllen | <new> new | <e1> e1 | <e2> e2 | <e3> e3 | <e4> e4 | ... | <eN> eN | zlend "];
p [label = "为 eN-1 扩展 eN 的 previous_entry_length 属性 \n 连锁更新到此结束", shape = plaintext];
p -> ziplist:eN;
}](_images/graphviz-7aabda3e118e21556488da60d6198b29c5d7f554.png)
第 8 章：对象¶
![digraph {
label = "\n 图 8-1 int 编码的字符串对象";
rankdir = LR;
node [shape = record];
redisObject [label = " redisObject | type \n REDIS_STRING | encoding \n REDIS_ENCODING_INT | <ptr> ptr | ... "];
node [shape = plaintext];
number [label = "10086"]
redisObject:ptr -> number;
}](_images/graphviz-c0ba08ec03934562687cc3cb79580e76edef81e3.png)
![digraph {
label = "\n 图 8-2 raw 编码的字符串对象";
rankdir = LR;
node [shape = record];
redisObject [label = " redisObject | type \n REDIS_STRING | encoding \n REDIS_ENCODING_RAW | <ptr> ptr | ... "];
sdshdr [label = " <head> sdshdr | free \n 0 | len \n 37 | <buf> buf"];
buf [label = " { 'L' | 'o' | 'n' | 'g' | ... | 'k' | 'i' | 'n' | 'g' | ' ' | '.' | '.' | '.' | '\\0' } " ];
//
redisObject:ptr -> sdshdr:head;
sdshdr:buf -> buf;
}](_images/graphviz-8ab5e59accdfa496f966cf90b45b146fb4959335.png)
![digraph {
label = "\n 图 8-4 embstr 编码的字符串对象";
node [shape = record];
embstr [ label = " { redisObject | { type \n REDIS_STRING | encoding \n REDIS_ENCODING_EMBSTR | <ptr> ptr | ... } } | { sdshdr | { free \n 0 | len \n 5 | { buf | { <buf> 'h' | 'e' | 'l' | 'l' | 'o' | '\\0'}} }} " ];
embstr:ptr -> embstr:buf;
}](_images/graphviz-900c13b23ce79372939259603be936c955ccaa62.png)
![digraph {
label = "\n 图 8-5 ziplist 编码的 numbers 列表对象";
rankdir = LR;
node [shape = record];
redisObject [label = " redisObject | type \n REDIS_LIST | encoding \n REDIS_ENCODING_ZIPLIST | <ptr> ptr | ... "];
ziplist [label = " { zlbytes | zltail | zllen | 1 | \"three\" | 5 | zlend } "];
redisObject:ptr -> ziplist;
}](_images/graphviz-a8d31075b4c0537f4eb6d84aaba1df928c67c953.png)
![digraph {
label = "\n 图 8-6 linkedlist 编码的 numbers 列表对象";
rankdir = LR;
node [shape = record];
redisObject [label = " redisObject | type \n REDIS_LIST | encoding \n REDIS_ENCODING_LINKEDLIST | <ptr> ptr | ... "];
subgraph cluster_linked_list {
label = "链表";
style = dashed;
node1 [label = "StringObject \n 1 "];
node2 [label = "StringObject \n \"three\""];
node3 [label = "StringObject \n 5 "];
node1 -> node2 -> node3;
}
redisObject:ptr -> node1;
}](_images/graphviz-84c0d231f30c740a431407c7aaf3851b96399590.png)
![digraph {
label = "\n 图 8-9 ziplist 编码的 profile 哈希对象";
rankdir = LR;
node [shape = record];
redisObject [label = " redisObject | type \n REDIS_HASH | encoding \n REDIS_ENCODING_ZIPLIST | <ptr> ptr | ... "];
ziplist [label = " 压缩列表 ", width = 4.0];
redisObject:ptr -> ziplist;
}](_images/graphviz-d2524c9fe90fb5d91b5875107b257e0053794a2a.png)
![digraph {
label = "\n 图 8-10 profile 哈希对象的压缩列表底层实现";
//
node [shape = record];
ziplist [label = " zlbytes | zltail | zllen | <key1> \"name\" | <value1> \"Tom\" | <key2> \"age\" | <value2> 25 | <key3> \"career\" | <value3> \"Programmer\" | zlend "];
node [shape = plaintext];
edge [style = dashed];
kv1 [label = "第一个添加的键值对"];
kv1 -> ziplist:key1 [label = "键"];
kv1 -> ziplist:value1 [label = "值"];
kv2 [label = "第二个添加的键值对"];
kv2 -> ziplist:key2;
kv2 -> ziplist:value2;
kvN [label = "最新添加的键值对"];
kvN -> ziplist:key3;
kvN -> ziplist:value3;
}](_images/graphviz-7ba8b1f3af17e2e62cdf43608914333bf14d8e91.png)
![digraph {
label = "\n 图 8-11 hashtable 编码的 profile 哈希对象";
rankdir = LR;
//
node [shape = record];
redisObject [label = " redisObject | type \n REDIS_HASH | encoding \n REDIS_ENCODING_HT | <ptr> ptr | ... "];
dict [label = " <head> dict | <key1> StringObject \n \"age\" | <key2> StringObject \n \"career\" | <key3> StringObject \n \"name\" ", width = 1.5];
age_value [label = "StringObject \n 25"];
career_value [label = "StringObject \n \"Programmer\""];
name_value [label = "StringObject \n \"Tom\""];
//
redisObject:ptr -> dict:head;
dict:key1 -> age_value;
dict:key2 -> career_value;
dict:key3 -> name_value;
}](_images/graphviz-68cb863d265a1cd1ccfb038d44ce6b856ebbbe3a.png)
![digraph {
label = "\n 图 8-12 intset 编码的 numbers 集合对象";
rankdir = LR;
node [shape = record];
redisObject [label = " redisObject | type \n REDIS_SET | encoding \n REDIS_ENCODING_INTSET | <ptr> ptr | ... "];
intset [label = " <head> intset | encoding \n INTSET_ENC_INT16 | length \n 3 | <contents> contents "];
contents [label = " { 1 | 3 | 5 } "];
redisObject:ptr -> intset:head;
intset:contents -> contents;
}](_images/graphviz-fbd8f0e1aaad0bdef314af55d01212f83cba8b59.png)
![digraph {
label = "\n 图 8-13 hashtable 编码的 fruits 集合对象";
rankdir = LR;
node [shape = record];
redisObject [label = " redisObject | type \n REDIS_SET | encoding \n REDIS_ENCODING_HT | <ptr> ptr | ... "];
dict [label = " <head> dict | <cherry> StringObject \n \"cherry\" | <apple> StringObject \n \"apple\" | <banana> StringObject \n \"banana\" ", width = 1.5];
redisObject:ptr -> dict:head;
node [shape = plaintext, label = "NULL"];
dict:apple -> nullX;
dict:banana -> nullY;
dict:cherry -> nullZ;
}](_images/graphviz-3f77c5cca338422f418d6d11bc02109fc945e790.png)
![digraph {
label = "\n 图 8-14 ziplist 编码的有序集合对象";
rankdir = LR;
node [shape = record];
redisObject [label = " redisObject | type \n REDIS_ZSET | encoding \n REDIS_ENCODING_ZIPLIST | <ptr> ptr | ... "];
ziplist [label = "压缩列表", width = 4.0];
redisObject:ptr -> ziplist;
}](_images/graphviz-61b04c9bb72915ec0374125ba9455bc6783db4ff.png)
![digraph {
label = "\n 图 8-15 有序集合元素在压缩列表中按分值从小到大排列";
//
node [shape = record];
ziplist [label = " zlbytes | zltail | zllen | <banana> \"banana\" | <banana_price> 5.0 | <cherry> \"cherry\" | <cherry_price> 6.0 | <apple> \"apple\" | <apple_price> 8.5 | zlend "];
node [shape = plaintext];
banana [label = "分值最少的元素"];
cherry [label = "分值排第二的元素"];
apple [label = "分值最大的元素"];
//
banana -> ziplist:banana [label = "成员"];
banana -> ziplist:banana_price [label = "分值"];
cherry -> ziplist:cherry;
cherry -> ziplist:cherry_price;
apple -> ziplist:apple;
apple -> ziplist:apple_price;
}](_images/graphviz-243db42f3ae9ad5bb64108c999f7ce7144f166a6.png)
![digraph {
label = "\n 图 8-16 skiplist 编码的有序集合对象";
rankdir = LR;
node [shape = record];
redisObject [label = " redisObject | type \n REDIS_ZSET | encoding \n REDIS_ENCODING_SKIPLIST | <ptr> ptr | ... "];
zset [label = " <head> zset | <dict> dict | <zsl> zsl "];
node [shape = plaintext];
dict [label = "..."];
zsl [label = "..."];
redisObject:ptr -> zset:head;
zset:dict -> dict;
zset:zsl -> zsl;
}](_images/graphviz-122e7ebdcd23e888fae17c21813be048c2d3f0a8.png)
![digraph {
rankdir = LR;
//
node [shape = record];
zset [label = " <head> zset | <dict> dict | <zsl> zsl "];
dict [label = " <head> dict | ... | <ht0> ht[0] | ... "];
ht0 [label = " <head> dictht | ... | <table> table | ... "];
table [label = " <banana> StringObject \n \"banana\" | <apple> StringObject \n \"apple\" | <cherry> StringObject \n \"cherry\" "];
node [shape = plaintext];
apple_price [label = "8.5"];
banana_price [label = "5.0"];
cherry_price [label = "6.0"];
//
zset:dict -> dict:head;
dict:ht0 -> ht0:head;
ht0:table -> table:head;
table:apple -> apple_price;
table:banana -> banana_price;
table:cherry -> cherry_price;
//
node [shape = record, width = "0.5"];
//
l [label = " <header> header | <tail> tail | level \n 5 | length \n 3 "];
subgraph cluster_nodes {
style = invisible;
header [label = " <l32> L32 | ... | <l5> L5 | <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 "];
bw_null [label = "NULL", shape = plaintext];
level_null [label = "NULL", shape = plaintext];
A [label = " <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 | <backward> BW | 5.0 | StringObject \n \"banana\" "];
B [label = " <l2> L2 | <l1> L1 | <backward> BW | 6.0 | StringObject \n \"cherry\" "];
C [label = " <l5> L5 | <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 | <backward> BW | 8.5 | StringObject \n \"apple\" "];
}
subgraph cluster_nulls {
style = invisible;
n1 [label = "NULL", shape = plaintext];
n2 [label = "NULL", shape = plaintext];
n3 [label = "NULL", shape = plaintext];
n4 [label = "NULL", shape = plaintext];
n5 [label = "NULL", shape = plaintext];
}
//
l:header -> header;
l:tail -> C;
header:l32 -> level_null;
header:l5 -> C:l5;
header:l4 -> A:l4;
header:l3 -> A:l3;
header:l2 -> A:l2;
header:l1 -> A:l1;
A:l4 -> C:l4;
A:l3 -> C:l3;
A:l2 -> B:l2;
A:l1 -> B:l1;
B:l2 -> C:l2;
B:l1 -> C:l1;
C:l5 -> n5;
C:l4 -> n4;
C:l3 -> n3;
C:l2 -> n2;
C:l1 -> n1;
bw_null -> A:backward -> B:backward -> C:backward [dir = back];
zset:zsl -> l:header;
// HACK: 放在开头的话 NULL 指针的长度会有异样
label = "\n 图 8-17 有序集合元素同时被保存在字典和跳跃表中";
}](_images/graphviz-75ee561bcc63f8ea960d0339768aec97b1f570f0.png)
![digraph {
label = "\n 图 8-18 LLEN 命令执行时的类型检查过程";
//
call_command [label = "客户端发送 LLEN <key> 命令", shape = box];
check_type [label = "服务器检查 \n 键 key 的值对象\n是否列表对象", shape = diamond];
execute_command [label = "对键 key 执行 LLEN 命令", shape = box];
type_error [label = "返回一个类型错误", shape = box];
//
call_command -> check_type;
check_type -> execute_command [label = "是"];
check_type -> type_error [label = "否"];
}](_images/graphviz-bb97ad72ffdd0886759fb83ac6276ab832ba9193.png)
![digraph {
label = "\n 图 8-19 LLEN 命令的执行过程";
//
node [shape = box];
call_command [label = "客户端发送 LLEN <key> 命令"];
check_type [label = "服务器检查 \n 键 key 的值对象\n是否列表对象", shape = diamond];
//execute_command [label = "对键 key 执行 LLEN 命令"];
select_encoding [label = "对象的编码是 \n ziplist 还是 linkedlist ？", shape = diamond];
ziplist [label = "调用 ziplistLen 函数 \n 返回压缩列表的长度"];
linkedlist [label = "调用 listLength 函数 \n 返回双端链表的长度"];
type_error [label = "返回一个类型错误"];
//
call_command -> check_type;
//check_type -> execute_command [label = "是"];
check_type -> type_error [label = "否"];
//execute_command -> select_encoding;
check_type -> select_encoding [label = "是"];
select_encoding -> ziplist [label = "ziplist \n 编码"];
select_encoding -> linkedlist [label = "linkedlist \n 编码"];
}](_images/graphviz-6968058778bf21d6e975a903e47b232c72fdadd1.png)
![digraph {
label = "\n 图 8-23 引用数为 3 的共享对象";
rankdir = LR;
server [label = "服务器程序", shape = box, width = 1.5];
key_a [label = "键 A", shape = box, width = 1.5];
key_b [label = "键 B", shape = box, width = 1.5];
redisObject [label = " <head> redisObject | type \n REDIS_STRING | encoding \n REDIS_ENCODING_INT | <ptr> ptr | refcount \n 3 | ... ", shape = record];
node [shape = plaintext];
number [label = "100"]
redisObject:ptr -> number;
key_a -> redisObject:head;
key_b -> redisObject:head;
server -> redisObject:head;
}](_images/graphviz-b67a99e375084b9847331a258fb5a98373562122.png)
![digraph {
label = "\n 图 9-1 服务器数据库示例";
rankdir = LR;
node [shape = record];
//
redisServer [label = "redisServer | ... | <db> db | ... | dbnum \n 16 | ..."];
db [label = "{ <0> db[0] | <1> db[1] | <2> db[2] | ... | <15> db[15] }"];
//
redisServer:db -> db;
}](_images/graphviz-6d5a23554720addffde00d34f9f6212498203291.png)
![digraph {
label = "\n图 9-4 数据库键空间例子";
rankdir = LR;
node [shape = record];
//
redisDb [label = "redisDb | ... | <dict> dict | ..."];
dict [label = "<dict> dict | <alphabet> StringObject \n \"alphabet\" | <book> StringObject \n \"book\" | <message> StringObject \n \"message\""];
subgraph cluster_alphabet {
a [label = " StringObject \n \"a\" "];
b [label = " StringObject \n \"b\" "];
c [label = " StringObject \n \"c\" "];
a -> b -> c;
label = "ListObject";
}
//alphabet [label = "<head> ListObject | { StringObject \n \"a\" | \"b\" | \"c\" }"];
book [label = "<head> HashObject | <name> StringObject \n \"name\" | <author> StringObject \n \"author\" | <publisher> StringObject \n \"publisher\""];
//name [label = " StringObject \n \"Redis in Action\""];
name [label = " StringObject \n \"Redis in Action\""];
author [label = " StringObject \n \"Josiah L. Carlson\""];
publisher [label = " StringObject \n \"Manning\""];
message [label = " StringObject \n \"hello world\""];
//
redisDb:dict -> dict:dict;
dict:alphabet -> a;
dict:book -> book:head;
dict:message -> message;
book:name -> name;
book:publisher -> publisher;
book:author -> author;
}](_images/graphviz-b1bea528da9b180dc035546f23f8956a242fc0f5.png)
![digraph {
label = "\n图 9-12 带有过期字典的数据库例子";
rankdir = LR;
node [shape = record];
//
redisDb [label = "redisDb | ... | <dict> dict | <expires> expires | ..."];
dict [label = "<dict> dict | <alphabet> StringObject \n \"alphabet\" | <book> StringObject \n \"book\" | <message> StringObject \n \"message\""];
subgraph cluster_alphabet {
a [label = " StringObject \n \"a\" "];
b [label = " StringObject \n \"b\" "];
c [label = " StringObject \n \"c\" "];
a -> b -> c;
label = "ListObject";
}
book [label = "<head> HashObject | <name> StringObject \n \"name\" | <author> StringObject \n \"author\" | <publisher> StringObject \n \"publisher\""];
name [label = "<head> StringObject \n \"Redis in Action\""];
author [label = "<head> StringObject \n \"Josiah L. Carlson\""];
publisher [label = "<head> StringObject \n \"Manning\""];
message [label = "<head> StringObject \n \"hello world\""];
//
expires [label = "<head> dict | <alphabet> StringObject \n \"alphabet\" | <book> StringObject \n \"book\""];
redisDb:expires -> expires:head;
alphabet_expire [label = "<head> long long | 1385877600000"];
book_expire [label = "<head> long long | 1388556000000"];
expires:alphabet -> alphabet_expire:head;
expires:book -> book_expire:head;
//
redisDb:dict -> dict:dict;
dict:alphabet -> a;
dict:book -> book:head;
dict:message -> message:head;
book:name -> name:head;
book:publisher -> publisher:head;
book:author -> author:head;
}](_images/graphviz-a98e948b7df5bec0a324d87ba3f12bb965e8bd00.png)
![digraph {
label = "\n图 9-16 GET 命令的执行过程";
node [shape = box];
//
get [label = "GET <key>"];
key_exists_or_not [label = "键不存在？", shape = diamond];
key_expired_or_not [label = "键已过期？", shape = diamond];
return_nil [label = "返回空回复"];
return_value [label = "返回键 key 的值"];
//
get -> key_exists_or_not;
key_exists_or_not -> return_nil [label = "是"];
key_exists_or_not -> key_expired_or_not [label = "否"];
key_expired_or_not -> return_nil [label = "是\n删除过期键"];
key_expired_or_not -> return_value [label = "否"];
}](_images/graphviz-bea3896f8f78c1121ed10c3963085383f28e69df.png)
![digraph {
label = "\n图 9-17 主从服务器删除过期键 （1）";
rankdir = LR;
//
node [shape = record];
subgraph cluster_master {
label = "主服务器";
master_db [label = " 数据库 | message \n （已过期） | xxx | yyy "];
}
subgraph cluster_slave {
label = "从服务器";
slave_db [label = " 数据库 | message \n （已过期） | xxx | yyy "];
}
//
master_db -> slave_db [style = invis, minlen = 2];
}](_images/graphviz-6e917ce52dd6b7229798347a6a0c7b271b6346ae.png)
![digraph {
label = "\n图 9-18 主从服务器删除过期键 （2）";
rankdir = LR;
//
node [shape = record];
subgraph cluster_master {
label = "主服务器";
master_db [label = " 数据库 | message \n （已过期） | xxx | yyy "];
}
subgraph cluster_slave {
label = "从服务器";
slave_db [label = " 数据库 | <message> message \n （已过期） | xxx | yyy "];
}
client [label = "客户端", shape = circle];
//
splines = polyline;
master_db -> slave_db [style = invis, minlen = 2];
slave_db -> client [dir = back, label = "GET message"];
slave_db -> client [label = "(nil)"];
}](_images/graphviz-9839089a12e44ba12c2237a4c250bfe0e004e15b.png)
![digraph {
label = "\n图 9-19 主从服务器删除过期键 （3）";
rankdir = LR;
//
node [shape = record];
subgraph cluster_master {
label = "主服务器";
master_db [label = " 数据库 | xxx | yyy ", width = 1.25, height = 1.75];
}
subgraph cluster_slave {
label = "从服务器";
slave_db [label = " 数据库 | <message> message \n （已过期） | xxx | yyy "];
}
client [label = "客户端", shape = circle];
//
splines = polyline;
master_db -> slave_db [label = "DEL message"];
client -> master_db [label = "GET message"];
client -> master_db [dir = back, label = "(nil)"];
}](_images/graphviz-763e7edad215846a6cf6a99999eeace75f99d5de.png)
![digraph {
label = "\n图 9-20 主从服务器删除过期键 （4）";
rankdir = LR;
//
node [shape = record, width = 1.25, height = 1.75];
subgraph cluster_master {
label = "主服务器";
master_db [label = " 数据库 | xxx | yyy "];
}
subgraph cluster_slave {
label = "从服务器";
slave_db [label = " 数据库 | xxx | yyy "];
}
//
master_db -> slave_db [style = invis, minlen = 2];
}](_images/graphviz-bb687147c3aba0b825b951326887947d07d53624.png)
第 10 章：RDB 持久化¶
Redis 服务器数据库示例。
![digraph {
rankdir = LR;
node [shape = record];
label = "\n图 10-1 数据库状态示例";
subgraph cluster_server {
label = "Redis 服务器";
db0 [label = "数据库 0 | { k1 | v1} | { k2 | v2 } | { k3 | v3 }"];
db1 [label = "数据库 1 | { k1 | v1} | { k2 | v2 } | { k3 | v3 }"];
db2 [label = "数据库 2 | { k1 | v1} | { k2 | v2 } | { k3 | v3 }"];
db0->db1 -> db2 [style = invis];
}
}](_images/graphviz-8a39c23741ca2d627dbb285bbc89b58d4a4b54d3.png)
Redis 保存和载入 RDB 文件的流程。
![digraph {
rankdir = LR;
label = "\n图 10-2 将数据库状态保存为 RDB 文件";
//
state [label = "数据库状态", shape = circle];
rdb [label = "RDB 文件", shape = note, height = 1.8, width = 1.4];
//
state -> rdb [label = "保存为", minlen = 2.5];
}](_images/graphviz-798fc56f5bdbd23098e3880a0d90b79a9e6708f9.png)
![digraph {
rankdir = LR;
label = "\n图 10-3 用 RDB 文件来还原数据库状态";
//
state [label = "数据库状态", shape = circle];
rdb [label = "RDB 文件", shape = note, height = 1.8, width = 1.4];
//
state -> rdb [dir = back, label = "还原", minlen = 2.5];
}](_images/graphviz-d41bde2b83e67cb9599ee75dbaf4d5feb7242a53.png)
![digraph {
label = "\n图 10-4 服务器载入文件时的判断流程";
node [shape = box];
//
server_star [label = "服务器启动", width = 3]
start_load [label = "执行载入程序", width = 3];
aof_or_not [label = "已开启 AOF 持久化功能？", shape = diamond];
load_by_aof [label = "载入 AOF 文件"];
load_by_rdb [label = "载入 RDB 文件"];
//
server_star -> start_load -> aof_or_not;
aof_or_not -> load_by_aof [label = "是"];
aof_or_not -> load_by_rdb [label = "否"];
}](_images/graphviz-986d4a4a299a82a0cd9189c88eff8df037620bfe.png)
![digraph {
label = "\n图 10-5 创建和载入 RDB 文件";
rankdir = LR;
splines = polyline
//
node [shape = circle, width = 1.3, height = 1.3];
state [label = "数据库状态"];
rdb [label = "RDB 文件"];
//
edge [minlen = 2.5];
state -> rdb [label = "rdbSave"];
rdb -> state [label = "\nrdbLoad"];
}](_images/graphviz-ee236a7d053c54dd556f416a721361dbd58cf03c.png)
自动间隔性保存¶
记录了服务器触发自动 BGSAVE 条件的 saveparams 属性。
![digraph {
label = "\n图 10-6 服务器状态中的保存条件";
rankdir = LR;
node [shape = record];
//
redisServer [label = " redisServer | ... | <saveparams> saveparams | ... "];
saveparams [label = " { { saveparams[0] | seconds \n 900 | changes \n 1 } | { saveparams[1] | seconds \n 300 | changes \n 10 } | { saveparams[2] | seconds \n 60 | changes \n 10000 } } "];
//
redisServer:saveparams -> saveparams;
}](_images/graphviz-153da551bf9e92b62462918adadb65719a0ca943.png)
记录服务器最后一次执行 SAVE 或者 BGSAVE 的时间，
以及自最后一次保存 RDB 文件以来，
服务器进行了多少次写入的 lastsave 属性和 dirty 属性。
![digraph {
label = "\n图 10-7 服务器状态示例";
rankdir = LR;
node [shape = record];
//
redisServer [label = " redisServer | ... | dirty \n 123 | lastsave \n 1378270800 | ... "];
}](_images/graphviz-d5752af0944a18d5528c28dea77bdb4b05a339d6.png)
用于记录和检查服务器是否需要自动执行 BGSAVE 的相关属性和数据结构的示例。
![digraph {
label = "\n图 10-8 服务器状态";
rankdir = LR;
node [shape = record];
//
redisServer [label = " redisServer | ... | <saveparams> saveparams | ... | dirty \n 123 | lastsave \n 1378270800 | ... "];
saveparams [label = " { { saveparams[0] | seconds \n 900 | changes \n 1 } | { saveparams[1] | seconds \n 300 | changes \n 10 } | { saveparams[2] | seconds \n 60 | changes \n 10000 } } "];
//
redisServer:saveparams -> saveparams;
}](_images/graphviz-4c1e6c09a6bc61293ab66453d8f44c2fa384452c.png)
RDB 文件结构¶
RDB 文件的总体结构。
![digraph {
label = "\n图 10-10 RDB 文件结构";
node [shape = record];
rdb [label = " REDIS | db_version | databases | EOF | check_sum "];
}](_images/graphviz-6e887288b93260b3d6ebfdece316276c2e5295c9.png)
包含数据库 0 和数据库 3 的非空 RDB 文件结构示例。
![digraph {
label = "\n图 10-12 带有两个非空数据库的 RDB 文件示例";
node [shape = record];
rdb [label = " REDIS | db_version | database 0 | database 3 | EOF | check_sum "];
}](_images/graphviz-bd17f60df2182d64acb1bca39eaaff8c113b1c0b.png)
RDB 文件中的数据库结构。
![digraph {
label = "\n图 10-13 RDB 文件中的数据库结构";
node [shape = record];
database [label = " SELECTDB | db_number | key_value_pairs "];
}](_images/graphviz-098e60e3aee59877e2135910b18aecbee9600671.png)
示例。
![digraph {
label = "\n图 10-14 数据库结构示例";
node [shape = record];
value [label = " SELECTDB | 0 | key_value_pairs "];
}](_images/graphviz-a09ee7e4d84ddc0b83b7bc643f6d3508e773d2bd.png)
包含了数据库部分的 RDB 文件示例。
![digraph {
label = "\n图 10-15 RDB 文件中的数据库结构示例";
node [shape = record];
v [label = " REDIS | db_version | SELECTDB | 0 | pairs | SELECTDB | 3 | pairs | EOF | check_sum"];
}](_images/graphviz-7b5b907ea852666aa3f28d0ce666bd94234e9ed5.png)
不带过期时间的键值对结构。
![digraph {
label = "\n图 10-16 不带过期时间的键值对";
node [shape = record];
kvp [label = " TYPE | key | value "];
}](_images/graphviz-221587f8dc5aa7a0280c131b44ae2ea5f21e47a4.png)
示例。
![digraph {
label = "\n图 10-18 无过期时间的字符串键值对示例";
node [shape = record];
string [label = " REDIS_RDB_TYPE_STRING | key | value "];
}](_images/graphviz-399f2db07f64f8be3f778ae387091fb93d54cc72.png)
带有过期时间的键值对结构。
![digraph {
label = "\n图 10-17 带有过期时间的键值对";
node [shape = record];
kvp [label = " EXPIRETIME_MS | ms | TYPE | key | value "];
}](_images/graphviz-be169c701ae8db66da9f1eb0b1d69da5253179ae.png)
示例。
![digraph {
label = "\n图 10-19 带有过期时间的集合键值对示例";
node [shape = record];
set [label = " EXPIRETIME_MS | 1388556000000 | REDIS_RDB_TYPE_SET | key | value "];
}](_images/graphviz-6a02fd30c406631a2bc66942c91ec3d4766dfbf6.png)
int 编码的字符串对象的结构。
![digraph {
label = "\n图 10-20 INT 编码字符串对象的保存结构";
node [shape = record];
v [label = " ENCODING | integer "];
}](_images/graphviz-b7a2497e808531d46c05e25d85b063dae56cdb1a.png)
示例。
![digraph {
label = "\n图 10-21 用 8 位来保存整数的例子";
node [shape = record];
v [label = " REDIS_RDB_ENC_INT8 | 123 "];
}](_images/graphviz-97c91e91d7e08d22bd2eef0640a807e6d2fe5de5.png)
内容没有被压缩的字符串对象的结构。
![digraph {
label = "\n图 10-22 无压缩字符串的保存结构";
node [shape = record];
value [ label = " len | string "];
}](_images/graphviz-60743b5b5199ae3172961dd04b886aebafc81ccc.png)
示例。
![digraph {
label = "\n图 10-24 无压缩的字符串";
node [shape = record];
value [ label = " 5 | \"hello\" "];
}](_images/graphviz-f92f4d657873b98467f7d388ebac68219bc41dd8.png)
内容被压缩后的字符串对象的结构。
![digraph {
label = "\n图 10-23 压缩后字符串的保存结构";
node [shape = record];
value [ label = " REDIS_RDB_ENC_LZF | compressed_len | origin_len | compressed_string "];
}](_images/graphviz-3b82d4c74bb5056fbfdc736b22fa02d4ff51743f.png)
示例，
其中 ? 代表的是无法用字符串形式打印出来的字节。
![digraph {
label = "\n图 10-25 压缩后的字符串";
node [shape = record];
value [label = " REDIS_RDB_ENC_LZF | 6 | 21 | \"?aa???\" "];
}](_images/graphviz-b029dd5cf37e631d19577283fabf7de3da3dba39.png)
列表对象的结构。
![digraph {
label = "\n图 10-26 LINKEDLIST 编码列表对象的保存结构";
node [shape = record];
value [label = " list_length | item1 | item2 | ... | itemN "];
}](_images/graphviz-7813b37724ed00ea45f67d39b84429f6c4309c00.png)
示例。
![digraph {
label = "\n图 10-27 保存 LINKEDLIST 编码列表的例子";
node [shape = record];
list [label = " 3 | 5 | \"hello\" | 5 | \"world\" | 1 | \"!\" "];
}](_images/graphviz-a952d1b7172803692c31235cba90dc8fd6dc8bca.png)
集合对象的结构。
![digraph {
label = "\n图 10-28 HT 编码集合对象的保存结构";
node [shape = record];
value [ label = " set_size | elem1 | elem2 | ... | elemN "];
}](_images/graphviz-5c0556db8fbfa9707b2d9fdf9d3a36fa37cda948.png)
示例。
![digraph {
label = "\n图 10-29 保存 HT 编码集合的例子";
node [shape = record];
set [label = " 4 | 5 | \"apple\" | 6 | \"banana\" | 3 | \"cat\" | 3 | \"dog\" "];
}](_images/graphviz-5fd000e305cbb82318676adb0d3c641c068b83bb.png)
哈希对象的结构。
![digraph {
label = "\n图 10-30 HT 编码哈希表对象的保存结构";
node [shape = record];
hash [label = " hash_size | key_value_pair 1 | key_value_pair 2 | ... | key_value_pair N "];
}](_images/graphviz-cf4df030887b147abf6b1b4f0d562ec0e64cdfde.png)
更详细的哈希对象结构。
![digraph {
label = "\n图 10-32 更详细的 HT 编码哈希表对象的保存结构";
node [shape = record];
hash [label = " hash_size | key1 | value1 | key2 | value2 | ... | keyN | valueN "];
}](_images/graphviz-d72bf68a7f4eab336b3448c55642ac058ab7ae4c.png)
示例。
![digraph {
label = "\n图 10-33 保存 HT 编码哈希表的例子";
node [shape = record];
hash [label = " 2 | 1 | \"a\" | 5 | \"apple\" | 1 | \"b\" | 6 | \"banana\" "];
}](_images/graphviz-b4fad754a51b13223ef110eacaf73648ecf69f62.png)
有序集合对象结构。
![digraph {
label = "\n图 10-34 SKIPLIST 编码有序集合对象的保存结构";
node [shape = record];
zset [label = " sorted_set_size | element1 | element2 | ... | elementN "];
}](_images/graphviz-9c7c8783d61ecc27f0e5c0e354ac116720775cae.png)
更详细的有序集合对象结构。
![digraph {
label = "\n图 10-36 更详细的 SKIPLIST 编码有序集合对象的保存结构";
node [shape = record];
sorted_set [label = " sorted_set_size | member1 | score1 | member2 | score2 | ... | memberN | scoreN "];
}](_images/graphviz-4eccee1e3bb76e2fdda791119a2fc56a7a5fb06e.png)
示例。
![digraph {
label = "\n图 10-37 保存 SKIPLIST 编码有序集合的例子";
node [shape = record];
sorted_set [label = " 2 | 2 | \"pi\" | 4 | \"3.14\" | 1 | \"e\" | 3 | \"2.7\" "];
}](_images/graphviz-41b13838f8db4df01d8654f2fd92c1d2fef2181f.png)
第 11 章： AOF 持久化¶
Redis 服务器在进行 AOF 持久化时， 客户端、服务器与 AOF 文件之间的互动。
![digraph {
label = "\n图 11-1 AOF 持久化";
rankdir = LR;
//
client [label = "客户端", shape = circle, height = 1.3, width = 1.3];
server [label = "服务器", shape = box, width = 1.0, height = 2, width = 1.5];
aof [label = "AOF 文件", shape = note, height = 1.3];
//
client -> server [label = "发送写命令"];
server -> aof [label = "保存被执行的写命令"];
}](_images/graphviz-16fdfdbd47a104dd630d64c3fac994487c946be3.png)
AOF 文件的载入过程。
![digraph {
label = "\n 图 11-2 AOF 文件载入过程"
//
node [shape = box]
start_loading [label = "服务器启动载入程序", width = 4]
create_fake_client [label = "创建伪客户端", width = 4]
load_a_command_from_aof [label = "从 AOF 文件中分析并读取出一条写命令", width = 4]
exec_command_via_fake_client [label = "使用伪客户端执行写命令"]
all_command_exec_or_not [shape = diamond, label = "AOF 文件中的所有写命令\n都已经被执行完毕？"]
done [label = "载入完毕", width = 4]
//
start_loading -> create_fake_client -> load_a_command_from_aof -> exec_command_via_fake_client -> all_command_exec_or_not;
all_command_exec_or_not -> done [label = "是"]
all_command_exec_or_not -> load_a_command_from_aof [label = "否"]
}](_images/graphviz-47f5d1e9984e43cd2871a00527cc9c7c503e6500.png)
在进行 AOF 重写时， 服务器会同时将命令发送给 AOF 文件和 AOF 重写缓冲区。
![digraph {
label = "图 11-4 服务器同时将命令发送给 AOF 文件和 AOF 重写缓冲区";
rankdir = LR;
client [label = "客户端", shape = circle, height = 1.5];
subgraph cluster_server {
label = "服务器";
command_handler [label = "命\n令\n处\n理\n器", shape = box, height = 2.0];
aof_rewrite_buf [label = "AOF 重写缓冲区", shape = box];
aof_buf [label = "AOF 缓冲区", shape = box];
command_handler -> aof_rewrite_buf [label = "追加命令"];
command_handler -> aof_buf [label = "追加命令"];
}
client -> command_handler [label = "发送命令"];
}](_images/graphviz-18f207f6ae975d0ef15ddc37d0c25279f535ef5f.png)
第 12 章： 事件¶
Redis 的文件事件处理器的四个组成部分。
![digraph {
label = "\n 图 12-1 文件事件处理器的四个组成部分";
rankdir = LR;
node [shape = box];
subgraph cluster_sockets {
style = dashed
label = "套接字";
c1 [label = "s1", shape = circle];
c2 [label = "s2", shape = circle];
other_client [label = "...", width = 1.1, shape = plaintext];
c3 [label = "sN", shape = circle];
}
io_multiplexing [label = "I\n/\nO\n多\n路\n复\n用\n程\n序"];
file_event_processor [label = "文\n件\n事\n件\n分\n派\n器"];
subgraph cluster_handlers {
style = dashed
label = "事件处理器";
write_handler [label = "命令请求处理器"];
read_handler [label = "命令回复处理器"];
connect_handler [label = "连接应答处理器"];
other_handlers [label = "...", width = 1.6];
}
c1 -> io_multiplexing;
c2 -> io_multiplexing;
other_client -> io_multiplexing [style = invis];
c3 -> io_multiplexing;
io_multiplexing -> file_event_processor;
file_event_processor -> write_handler;
file_event_processor -> read_handler;
file_event_processor -> connect_handler;
file_event_processor -> other_handlers;
}](_images/graphviz-3c09f0e53bd9d786aa646e5e4c289a11d97d40d7.png)
I/O 多路复用程序通过队列向文件事件分派器传送套接字的过程。
![digraph {
rankdir = LR;
node [shape = record];
label = "\n图 12-2 I/O 多路复用程序通过队列向文件事件分派器传送套接字";
//
subgraph cluster_io_multiplexing {
//style = dashed
label = "队列";
queue [label = " { 套接字 sN | 套接字 sN-1 | ... | 套接字 s3 | 套接字 s2 } "];
}
file_event_processor [label = "文\n件\n事\n件\n分\n派\n器"];
//
queue -> file_event_processor [label = "传送\n 套接字 s1", style = dashed];
}](_images/graphviz-a06632048a0970072c8a20c202c9a0efeb07ddb6.png)
Redis 的 I/O 多路复用程序有多个 I/O 多路复用库可选。
![digraph {
label = "图 12-3 Redis 的 I/O 多路复用程序有多个 I/O 多路复用库实现可选";
node [shape = box];
io_multiplexing [label = "I/O 多路复用程序"];
subgraph cluster_imp {
style = dashed
label = "底层实现";
labelloc = "b";
kqueue [label = "kqueue"];
evport [label = "evport"];
epoll [label = "epoll"];
select [label = "select"];
}
//
edge [dir = back];
io_multiplexing -> select;
io_multiplexing -> epoll;
io_multiplexing -> evport;
io_multiplexing -> kqueue;
}](_images/graphviz-883af630a14f2796161bbd33a4e7e2824e01d478.png)
客户端与服务器通过事件应答来进行通信的过程。
![digraph {
label = "\n图 12-7 客户端和服务器的通讯过程";
splines = polyline;
rankdir = LR;
node [shape = box, height = 3.0];
client [label = "客\n户\n端"];
server [label = "服\n务\n器"];
client -> server [label = "客户端向服务器发送连接请求\n服务器执行连接应答处理器"];
client -> server [label = "\n\n客户端向服务器发送命令请求\n服务器执行命令请求处理器"];
server -> client [label = "\n\n服务器向客户端发送命令回复\n服务器执行命令回复处理器"];
}](_images/graphviz-e1519871fa7133b28f8dc71b3158814ead169525.png)
时间事件示例。
![digraph {
label = "\n图 12-8 用链表连接起来的三个时间事件";
rankdir = LR;
node [shape = record];
time_events [shape = plaintext];
te3 [label = "time_event | id\n3 | when\n1385877600030\n（2013年12月1日\n零时之后30毫秒） | timeProc\nhandler_3"];
te2 [label = "time_event | id\n2 | when\n1385877600000\n（2013年12月1日\n零时） | timeProc\nhandler_2"];
te1 [label = "time_event | id\n1 | when\n1385877600010\n（2013年12月1日\n零时之后10毫秒） | timeProc\nhandler_1"];
time_events -> te3 -> te2 -> te1;
}](_images/graphviz-bfc043bd5152a97fabf55da7d12b33512d22b941.png)
事件处理角度下的 Redis 服务器运行流程。
![digraph {
label = "\n图 12-10 事件处理角度下的服务器运行流程";
start_server [label = "启动服务器", shape = box];
server_close_or_not [label = "是否关闭服务器？", shape = diamond];
start_server -> server_close_or_not;
close_server [label = "关闭服务器", shape = box];
wait_for_file_event [label = "等待文件事件产生", shape = box];
handler_file_event [label = "处理已产生的文件事件", shape = box];
handler_time_event [label = "处理已达到的时间事件", shape = box];
wait_for_file_event -> handler_file_event -> handler_time_event;
//
server_close_or_not -> close_server [label = "是"];
server_close_or_not -> wait_for_file_event [label = "否"];
handler_time_event -> server_close_or_not [label = "开始新的事件循环"];
}](_images/graphviz-03e1d92303e2714abb2f8d719ef1546a9054e8ef.png)
第 13 章： 客户端¶
三个连接到服务器的客户端。
![digraph {
label = "\n 13-1 客户端与服务器";
rankdir = LR;
node [shape = circle, width = 1.2];
c1 [label = "客户端 1"];
c2 [label = "客户端 2"];
c3 [label = "客户端 3"];
node [shape = box, height = 4.0, width = 1.5];
server [label = "服\n务\n器"];
//
edge [dir = none, minlen = 2];
c1 -> server;
c2 -> server;
c3 -> server;
}](_images/graphviz-ad7debaf03e0f0b9d303afdd040be9f9dc642cc6.png)
这三个客户端在服务器状态 clients 属性中的样子。
![digraph {
label = "\n 13-2 clients 链表";
rankdir = LR;
//
node [shape = record];
redisServer [label = " redisServer | ... | <clients> clients | ... ", width = 2];
c1 [label = " redisClient\n（客户端 1） "];
c2 [label = " redisClient\n（客户端 2） "];
c3 [label = " redisClient\n（客户端 3） "];
//
redisServer:clients -> c1;
c1 -> c2;
c2 -> c3;
}](_images/graphviz-4b22fe21bc9e6d2be18d04b0c11b6aafc41e27b2.png)
Redis 客户端的输入缓冲区示例。
![digraph {
label = "\n 图 13-4 querybuf 属性示例";
rankdir = LR;
//
node [shape = record];
client [label = " redisClient | ... | <querybuf> querybuf | ... ", width = 2];
sdshdr [label = " <head> sdshdr | free \n 0 | len \n 33 | <buf> buf "];
buf [label = " { '*' | '3' | '\\r' | '\\n' | ... | 'v' | 'a' | 'l' | 'u' | 'e' | '\\r' | '\\n' | '\\0' } "];
//
client:querybuf -> sdshdr:head;
sdshdr:buf -> buf;
}](_images/graphviz-a31c14fe0328c4dbfcc11664c52869dfa9542060.png)
Redis 客户端的 argv 属性和 argc 属性示例。
![digraph {
label = "\n 图 13-5 argv 属性和 argc 属性示例";
rankdir = LR;
node [shape = record];
redisClient [label = " redisClient | ... | <argv> argv | argc \n 3 | ... ", width = 2];
argv [label = " { { <head> argv[0] | StringObject \n \"SET\" } | { argv[1] | StringObject \n \"key\" } | { argv[1] | StringObject \n \"value\" } } "];
redisClient:argv -> argv:head;
}](_images/graphviz-6067ad7f8adc5cca22ca3a67b2016d8905e180c8.png)
Redis 客户端的固定大小输出缓冲区示例。
![digraph {
label = "\n 图 13-8 固定大小缓冲区示例";
rankdir = LR;
node [shape = record];
redisClient [label = " redisClient | ... | <buf> buf | bufpos \n 5 | ... "];
buf [label = " { '+' | 'O' | 'K' | '\\r' | '\\n' | '\\0' | ... } "];
redisClient:buf -> buf;
}](_images/graphviz-7eb96276ca8fab58de1bdd3362c4f3548b2d07d7.png)
Redis 客户端的可变大小输出缓冲区示例。
![digraph {
label = "\n 图 13-9 可变大小缓冲区示例";
rankdir = LR;
node [shape = record];
redisClient [label = " redisClient | ... | <reply> reply | ... ", width = 2];
node [label = " <head> StringObject \n ... "];
redisClient:reply -> s1:head -> s2:head -> s3:head;
}](_images/graphviz-c2d90890b81bd0ff6dbabd6f00a75bb4609645d4.png)
![digraph {
label = "\n\n 图 14-1 客户端接收并发送命令请求的过程";
rankdir = LR;
node [shape = plaintext];
user [label = "用户"];
client [label = "客户端"];
server [label = "服务器"];
//
user -> client [label = "键入命令请求"];
client -> server [label = "将命令请求转换成协议格式\n然后发送"];
}](_images/graphviz-b4eb69529c920f353912414e6a7c6acb97084a58.png)
![digraph {
label = "\n\n 图 14-8 客户端接收并打印命令回复的过程";
rankdir = LR;
node [shape = plaintext];
user [label = "用户"];
client [label = "客户端"];
server [label = "服务器"];
//
server -> client [label = "回复处理器将协议格式的\n命令回复返回给客户端"];
client -> user [label = "将回复格式化成人类可读格式 \n 然后打印显示"];
}](_images/graphviz-d5c3b1b146228297a7057d1d8fdf11e80badb1de.png)
![digraph {
label = "\n 图 14-4 命令表";
rankdir = LR;
node [shape = record];
commands [label = " 命令表 | ... | <set> \"set\" | <get> \"get\" | ... | <sadd> \"sadd\" | ... | <rpush> \"rpush\" | ... | <publish> \"publish\" | ... ", width = 2.0];
set [label = " <head> redisCommand | name \n \"set\" | <proc> proc | arity \n -3 | sflags \n \"wm\" | ... "];
get [label = " <head> redisCommand | name \n \"get\" | <proc> proc | arity \n 2 | sflags \n \"r\" | ... "];
//sadd [label = " <head> redisCommand | name \n \"sadd\" | <proc> proc | arity \n -3 | sflags \n \"wm\" | ... "];
//rpush [label = " <head> redisCommand | name \n \"rpush\" | <proc> proc | arity \n -3 | sflags \n \"wm\" | ... "];
//publish [label = " <head> redisCommand | name \n \"publish\" | <proc> proc | arity \n 3 | sflags \n \"pltr\" | ... "];
node [shape = plaintext];
setCommand [label = "void setCommand(redisClient *c);"];
getCommand [label = "void getCommand(redisClient *c);"];
//saddCommand;
//rpushCommand;
//publishCommand;
//
commands:set -> set:head; set:proc -> setCommand;
commands:get -> get:head; get:proc -> getCommand;
//commands:sadd -> sadd:head; sadd:proc -> saddCommand;
//commands:rpush -> rpush:head; rpush:proc -> rpushCommand;
//commands:publish -> publish:head; publish:proc -> publishCommand;
//* fix editor highlight
}](_images/graphviz-38d1a443b5626e8fd50f5981d0f2abd010efe0d7.png)
![digraph {
label = "\n 图 14-9 判断是否需要执行持久化操作";
//
node [shape = box]
start [label = "服务器没有在执行任何持久化操作"]
delay_bgrewriteaof_exists_or_not [shape = diamond, label = "有 BGREWRITEAOF 被延迟？"]
go_bgrewriteaof [label = "执行 BGREWRITEAOF"]
bgsave_satisfied_or_not [shape = diamond, label = "自动保存的条件已经满足？"]
go_bgsave [label = "执行 BGSAVE"]
bgrewriteaof_satisfied_or_not [shape = diamond, label = "AOF 重写的条件已经满足？"]
go_do_nothing [label = "不做动作"]
//
start -> delay_bgrewriteaof_exists_or_not
delay_bgrewriteaof_exists_or_not -> go_bgrewriteaof [label = "是"]
delay_bgrewriteaof_exists_or_not -> bgsave_satisfied_or_not [label = "否"]
bgsave_satisfied_or_not -> go_bgsave [label = "是"]
bgsave_satisfied_or_not -> bgrewriteaof_satisfied_or_not [label = "否"]
bgrewriteaof_satisfied_or_not -> go_bgrewriteaof [label = "是"]
bgrewriteaof_satisfied_or_not -> go_do_nothing [label = "否"]
}](_images/graphviz-0ba4963a397efe2b4badfd5a33bbfecc2b9cb00a.png)
第 15 章： 复制¶
SYNC 命令执行期间，
主从服务器的通信过程。
![digraph {
label = "\n 图 15-2 主从服务器在执行 SYNC 命令期间的通信过程"
rankdir = LR
splines = polyline
node [shape = box, height = 2]
master [label = "主\n服\n务\n器"]
slave [label = "从\n服\n务\n器"]
master -> slave [dir = back, label = "发送 SYNC 命令"]
master -> slave [label = "\n 发送 RDB 文件"]
master -> slave [label = "\n 发送缓冲区保存的所有写命令"]
}](_images/graphviz-97b9636a1ae5296d0dd59743f533ed887b80779a.png)
Redis 的命令传播过程示例。
![digraph {
label = "\n 图 15-3 处于一致状态的主从服务器"
rankdir = LR
node [shape = record, width = 2]
subgraph cluster_master {
label = "主服务器"
master_db [label = " <head> 数据库 | <k1> k1 | <k2> k2 | <k3> k3 | <k4> k4 | <k5> k5 "];
}
subgraph cluster_slave {
label = "从服务器"
slave_db [label = " <head> 数据库 | <k1> k1 | <k2> k2 | <k3> k3 | <k4> k4 | <k5> k5 "];
}
master_db -> slave_db [style = invis]
}](_images/graphviz-6815c2f60e501d13235281426dd7b35eb6cec98b.png)
如果这时，
客户端向主服务器发送命令 DEL k3 ，
那么主服务器在执行完这个 DEL 命令之后，
主从服务器的数据库将出现不一致：
主服务器的数据库已经不再包含键 k3 ，
但这个键却仍然包含在从服务器的数据库里面，
如图 15-4 所示。
![digraph {
label = "\n 图 15-4 处于不一致状态的主从服务器"
rankdir = LR
node [shape = circle]
client [label = "客户端"]
node [shape = record, width = 2]
subgraph cluster_master {
label = "主服务器"
master_db [label = " <head> 数据库 | <k1> k1 | <k2> k2 | <k4> k4 | <k5> k5 "];
}
subgraph cluster_slave {
label = "从服务器"
slave_db [label = " <head> 数据库 | <k1> k1 | <k2> k2 | <k3> k3 | <k4> k4 | <k5> k5 "];
}
master_db -> slave_db [style = invis]
client -> master_db [label = "发送命令 \n DEL k3"]
}](_images/graphviz-c762b83299748735aa6e348e52c1a709d0b15736.png)
在上面的例子中，
主服务器因为执行了命令 DEL k3 而导致主从服务器不一致，
所以主服务器将向从服务器发送相同的命令 DEL k3 ：
当从服务器执行完这个命令之后，
主从服务器将再次回到一致状态 ——
现在主从服务器两者的数据库都不再包含键 k3 了，
如图 15-5 所示。
![digraph {
label = "\n 图 15-5 主服务器向从服务器发送命令"
rankdir = LR
node [shape = record, width = 2]
subgraph cluster_master {
label = "主服务器"
master_db [label = " <head> 数据库 | <k1> k1 | <k2> k2 | <k4> k4 | <k5> k5 "];
}
subgraph cluster_slave {
label = "从服务器"
slave_db [label = " <head> 数据库 | <k1> k1 | <k2> k2 | <k4> k4 | <k5> k5 "];
}
master_db -> slave_db [label = "发送命令 \n DEL k3"]
}](_images/graphviz-87095964cd00b831c44b014be834272de718d1a6.png)
PSYNC 命令执行部分重同步时的过程。
![digraph {
rankdir = LR;
node [shape = record, height = 2];
splines = polyline;
master [label = "主\n服\n务\n器"];
slave [label = "从\n服\n务\n器"];
master -> slave [dir = back, label = "PSYNC"];
master -> slave [label = "\n+CONTINUE"];
master -> slave [label = "\n发送主从服务器断线期间\n主服务器执行的写命令"];
label = "\n图 15-6 主从服务器执行部分重同步的过程";
}](_images/graphviz-ea4df5d3f002721c72f35eeecb24d56e43461c6e.png)
Redis 的复制积压缓冲区的结构图。
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_master {
label = "主服务器";
propagater [label = "命令传播程序", height = 3.0];
backlog [label = "复制积压缓冲区"];
propagater -> backlog [label = "将写命令放入队列"];
}
node [height = 1.0];
subgraph cluster_slaves {
slave1 [label = "从服务器 A"];
slave2 [label = "从服务器 B"];
slave3 [label = "从服务器 C"];
style = invis;
}
edge [label = "发送写命令"]
backlog -> slave1 [style = invis];
propagater -> slave1;
propagater -> slave2;
propagater -> slave3;
label = "\n图 15-10 主服务器向复制积压缓冲区和所有从服务器传播写命令数据";
}](_images/graphviz-cda61ff7c43e48f7d440a29dca24e7a4c18c6889.png)
Redis 使用复制积压缓冲区来为断线的从服务器发送缺失数据的过程。
![digraph {
rankdir = LR;
node [shape = box, height = 1.0];
//
master [label = "主服务器\n\noffset = 10086"];
slave1 [label = "从服务器 A\n\noffset = 10086"];
slave2 [label = "从服务器 B\n\noffset = 10086"];
slave3 [label = "从服务器 C\n\noffset = 10086"];
//
edge [style = invis];
master -> slave1;
master -> slave2;
master -> slave3;
label = "\n图 15-7 拥有相同偏移量的主服务器和它的三个从服务器";
}](_images/graphviz-aa14465928963c3294df099f849dee43be08be6a.png)
![digraph {
rankdir = LR;
node [shape = box, height = 1.0];
//
master [label = "主服务器\n\noffset = 10119"];
slave1 [label = "从服务器 A\n\noffset = 10119"];
slave2 [label = "从服务器 B\n\noffset = 10119"];
slave3 [label = "从服务器 C\n\noffset = 10119"];
//
edge [label = "传播 33 字节数据"];
master -> slave1;
master -> slave2;
master -> slave3;
label = "\n图 15-8 更新偏移量之后的主从服务器";
}](_images/graphviz-21e515c3ed10e0d7a4b2e5e226a8a5ae0e7e899f.png)
![digraph {
rankdir = LR;
node [shape = box, height = 1.0];
//
master [label = "主服务器\n\noffset = 10119"];
slave1 [label = "从服务器 A\n\noffset = 10086"];
slave2 [label = "从服务器 B\n\noffset = 10119"];
slave3 [label = "从服务器 C\n\noffset = 10119"];
//
edge [label = "传播 33 字节数据"];
master -> slave1 [style = dotted, dir = none, label = "（断线）"];
master -> slave2;
master -> slave3;
label = "\n图 15-9 因为断线而处于不一致状态的从服务器 A";
}](_images/graphviz-006edcd29b6f3ed0c9618ffdb28ebae5c047bd2f.png)
![digraph {
rankdir = LR;
node [shape = box, height = 1.0];
//
master [label = "主服务器\n\noffset = 10119"];
slave1 [label = "从服务器 A\n\noffset = 10119"];
slave2 [label = "从服务器 B\n\noffset = 10119"];
slave3 [label = "从服务器 C\n\noffset = 10119"];
//
master -> slave1 [label = "发送断线时缺失的\n 33 字节数据"];
master -> slave2 [style = invis, dir = none];
master -> slave3 [style = invis, dir = none];
label = "\n图 15-11 主服务器向从服务器发送缺失的数据";
}](_images/graphviz-f6bc4ff370b34ed8a308808cd8ad35cefa719dca.png)
PSYNC 命令判断是执行部分重同步还是完整重同步的流程。
![digraph {
node [shape = box];
data_sync [label = "从服务器接到客户端发来的 SLAVEOF 命令"];
have_cache_or_not [label = "这是从服务器第一次执行复制？", shape = diamond];
data_sync -> have_cache_or_not;
force_full_resync [label = "向主服务器发送\nPSYNC ? -1"];
try_partial_resync [label = "向主服务器发送\nPSYNC <runid> <offset>"];
have_cache_or_not -> force_full_resync [label = "是"];
have_cache_or_not -> try_partial_resync [label = "否"];
full_resync [label = "主服务器返回\n+FULLRESYNC <runid> <offset>\n执行完整重同步"];
force_full_resync -> full_resync;
master_return_continue_or_not [label = "主服务器返回 +CONTINUE ？", shape = diamond];
try_partial_resync -> master_return_continue_or_not;
master_return_continue_or_not -> full_resync [label = "否"];
partial_resync [label = "执行部分重同步"];
master_return_continue_or_not -> partial_resync [label = "是"];
label = "\n图 15-12 PSYNC 执行完整重同步和部分重同步时可能遇上的情况";
}](_images/graphviz-05c9723c0862aecf99485314d7de36c440686539.png)
Redis 服务器监测命令缺失，并补发缺失命令的过程。
![digraph {
label = "\n 图 15-23 主从服务器处于一致状态"
rankdir = LR;
node [shape = box, height = 2]
master [label = "主服务器\n复制偏移量为 200"]
slave [label = "从服务器\n复制偏移量为 200"]
master -> slave [style = invis]
}](_images/graphviz-62d73bb577babc9671f8e306c0ddd10e1c3c84de.png)
如果这时主服务器执行了命令 SET key value （协议格式的长度为 33 字节），
将自己的复制偏移量更新到了 233 ，
并尝试向从服务器传播命令 SET key value ，
但这条命令却因为网络故障而在传播的途中丢失，
那么主从服务器之间的复制偏移量就会出现不一致：
主服务器的复制偏移量会被更新为 233 ，
而从服务器的复制偏移量仍然为 200 ，
如图 15-24 所示。
![digraph {
label = "\n 图 15-24 主从服务器处于不一致状态"
rankdir = LR;
node [shape = box]
master [label = "主服务器\n复制偏移量为 233", height = 2]
stop [shape = point]
slave [label = "从服务器\n复制偏移量为 200", height = 2]
master -> stop [label = "SET key value", style = dashed]
stop -> slave [style = invis]
}](_images/graphviz-f4772113dab802b5a71caf98031aad7286fd1acf.png)
在这之后，
当从服务器向主服务器发送 REPLCONF ACK 命令的时候，
主服务器会察觉从服务器的复制偏移量依然为 200 ，
而自己的复制偏移量为 233 ，
这说明复制积压缓冲区里面复制偏移量为 201 至 233 的数据（也即是命令 SET key value ）在传播过程中丢失了，
于是主服务器会再次向从服务器传播命令 SET key value ，
从服务器通过接收并执行这个命令可以将自己更新至主服务器当前所处的状态，
如图 15-25 所示。
![digraph {
label = "\n 图 15-25 主服务器向从服务器补发缺失的数据"
rankdir = LR
splines = polyline
node [shape = box, height = 2]
master [label = "主服务器\n复制偏移量为 233"]
slave [label = "从服务器\n复制偏移量为 233"]
master -> slave [dir = back, label = "REPLCONF ACK 200"]
master -> slave [label = "\nSET key value"]
}](_images/graphviz-f917c687bc15708bcbb0da53f98ca9fe94739471.png)
第 16 章： Sentinel¶
Sentinel 状态以及已连接的两个 Sentinel 实例结构。
![digraph {
label = "\n 图 16-5 master1 的实例结构";
rankdir = LR;
node [shape = record];
//
master1 [label = " <head> sentinelRedisInstance | flags \n SRI_MASTER | name \n \"master1\" | runid \n \"ee07959afc9d061233191c0f5bfe29580dfad0f4\" | config_epoch \n 0 | <addr> addr | down_after_period \n 30000 | quorum \n 2 | parallel_syncs \n 1 | failover_timeout \n 900000 | ... "];
addr [label = " <head> sentinelAddr | ip \n \"127.0.0.1\" | port \n 6379 "];
//
master1:addr -> addr:head;
}](_images/graphviz-bd4b7182673260277e8a82b509192fe2e4e2f662.png)
![digraph {
label = "\n 图 16-6 master2 的实例结构";
rankdir = LR;
node [shape = record];
//
master2 [label = " <head> sentinelRedisInstance | flags \n SRI_MASTER | name \n \"master2\" | runid \n \"a68408b775438a5dee54a638b3a6f3461920158a\" | config_epoch \n 0 | <addr> addr | down_after_period \n 50000 | quorum \n 5 | parallel_syncs \n 5 | failover_timeout \n 450000 | ... "];
addr [label = " <head> sentinelAddr | ip \n \"127.0.0.1\" | port \n 12345 "];
//
master2:addr -> addr:head;
}](_images/graphviz-3bfd988c3abd31392b4c1ff362740ac5b5e087b3.png)
![digraph {
label = "\n 图 16-7 Sentinel 状态以及 masters 字典";
rankdir = LR;
node [shape = record];
//
sentinelState [label = " sentinelState | <masters> masters | ... "];
masters [label = " <head> dict | <master1> \"master1\" | <master2> \"master2\" "];
master1 [label = " <head> sentinelRedisInstance | ... | name \n \"master1\" | ... "];
master2 [label = " <head> sentinelRedisInstance | ... | name \n \"master2\" | ... "];
//
sentinelState:masters -> masters:head;
masters:master1 -> master1:head;
masters:master2 -> master2:head;
}](_images/graphviz-b5c3067016489ac273ea53daa4d5fd47a5a27546.png)
Sentinel 通过向主服务器发送 INFO 命令来获得从服务器的信息。
![digraph {
label = "\n 图 16-9 Sentinel 向带有三个从服务器的主服务器发送 INFO 命令";
sentinel [label = "Sentinel", shape = box, width = 4.5, height = 1.0];
master [shape = doublecircle];
node [shape = circle];
edge [dir = none];
master -> slave0;
master -> slave1;
master -> slave2;
edge [dir = forward];
sentinel -> master [label = "INFO"];
}](_images/graphviz-e4867873c20993b8f7ec58b4534f23f9ca480fd2.png)
以及 Sentinel 为这个主服务器以及三个从服务器创建的信息结构。
![digraph {
label = "\n 图 16-10 主服务器和它的三个从服务器";
rankdir = LR;
node [shape = record];
master [label = " sentinelRedisInstance | flags \n SRI_MASTER | run_id \n \"7611c59dc3a29aa6fa0609f841bb6a1019008a9c\" | name \n \"master\" | ... | <slaves> slaves | ... "];
slaves [label = " <head> dict | <slave0> \"127.0.0.1:11111\" | <slave1> \"127.0.0.1:22222\" | <slave2> \"127.0.0.1:33333\" "];
slave0 [label = " <head> sentinelRedisInstance | flags \n SRI_SLAVE | name \n \"127.0.0.1:11111\" | ... "];
slave1 [label = " <head> sentinelRedisInstance | flags \n SRI_SLAVE | name \n \"127.0.0.1:22222\" | ... "];
slave2 [label = " <head> sentinelRedisInstance | flags \n SRI_SLAVE | name \n \"127.0.0.1:33333\" | ... "];
master:slaves -> slaves:head;
slaves:slave0 -> slave0:head;
slaves:slave1 -> slave1:head;
slaves:slave2 -> slave2:head;
}](_images/graphviz-0aaa934bbba0242636272cfe7b7e4840dee7c2f7.png)
Sentinel 通过命令连接向频道发送信息， 并通过订阅连接从频道中获取信息。
![digraph {
label = "\n 图 16-13 Sentinel 同时向服务器发送和接收信息";
rankdir = LR;
sentinel [label = "Sentinel", shape = box, height = 1.8];
master [label = "服务器", shape = circle];
sentinel -> master [label = "通过命令连接\n发送信息到频道"];
sentinel -> master [dir = back, label = "通过订阅连接\n从频道中接收信息"];
}](_images/graphviz-05e950c33ef0b91d3d0160f944d7460a16b86354.png)
示例：一个 Sentinel 向包括它自己在内的三个 Sentinel 发送信息。
![digraph {
label = "\n 图 16-14 向服务器发送信息";
node [shape = box];
sentinel1 [label = "sentinel1", width = 2.0];
sentinel2 [label = "sentinel2", width = 2.0];
sentinel3 [label = "sentinel3", width = 2.0];
server [label = "服务器", shape = circle];
edge [label = "发送信息\n（命令连接）"];
sentinel1 -> server;
edge [style = dashed];
edge [dir = back, label = "接收信息\n（订阅连接）"];
sentinel1 -> server;
sentinel2 -> server;
sentinel3 -> server;
}](_images/graphviz-e6387dd1193deb5d0efcdce04c3e250b8cfd914a.png)
Redis Sentinel 执行故障转移的整个过程。
![digraph {
label = "\n 图 16-22 将 server2 升级为主服务器";
subgraph cluster_servers {
style = invis;
node [shape = circle, width = 1.2];
edge [dir = none, style = dashed];
server1 [label = "server1", shape = doublecircle, style = dashed];
server2 [label = "server2"];
server3 [label = "server3"];
server4 [label = "server4"];
server1 -> server2;
server1 -> server3;
server1 -> server4;
}
sentinel_system [label = "领头 Sentinel", shape = box, width = 5.0, height = 1.0];
edge [label = "监视"];
sentinel_system -> server1 [style = dashed, label = "已下线", dir = none];
sentinel_system -> server2 [label = "发送命令\nSLAVEOF no one"];
sentinel_system -> server3 [dir = none];
sentinel_system -> server4 [dir = none];
}](_images/graphviz-2013e850c53fcfcda176421f6e1ac85052eb92d7.png)
![digraph {
label = "\n 图 16-23 server2 成功升级为主服务器";
subgraph cluster_servers {
style = invis;
node [shape = circle, width = 1.2];
edge [dir = none, style = dashed];
server1 [label = "server1", shape = doublecircle, style = dashed];
server2 [label = "server2", shape = doublecircle];
server3 [label = "server3"];
server4 [label = "server4"];
server1 -> server3;
server1 -> server4;
}
sentinel_system [label = "领头 Sentinel", shape = box, width = 5.0, height = 1.0];
edge [label = "监视", dir = none];
sentinel_system -> server1 [style = dashed, label = "已下线"];
sentinel_system -> server2;
sentinel_system -> server3;
sentinel_system -> server4;
}](_images/graphviz-fd12fbc76da1db8568db9dbca567335432be9857.png)
![digraph {
label = "\n 图 16-24 让从服务器复制新的主服务器";
subgraph cluster_servers {
style = invis;
node [shape = circle, width = 1.2];
edge [dir = none, style = dashed];
server1 [label = "server1", shape = doublecircle, style = dashed];
server2 [label = "server2", shape = doublecircle];
server3 [label = "server3"];
server4 [label = "server4"];
server1 -> server3;
server1 -> server4;
}
sentinel_system [label = "领头 Sentinel", shape = box, width = 5.0, height = 1.0];
sentinel_system -> server1 [style = dashed, label = "已下线", dir = none];
sentinel_system -> server2 [label = "监视", dir = none];
edge [label = "发送命令\nSLAVEOF\n<server2_ip>\n<server2_port>"];
sentinel_system -> server3;
sentinel_system -> server4;
}](_images/graphviz-9a97ef81f9a7fc395f3dd3a51f5ff129143eae48.png)
![digraph {
label = "\n 图 16-25 server3 和 server4 成为 server2 的从服务器";
subgraph cluster_servers {
style = invis;
node [shape = circle, width = 1.2];
edge [dir = none];
server1 [label = "server1", shape = doublecircle, style = dashed];
server2 [label = "server2", shape = doublecircle];
server3 [label = "server3"];
server4 [label = "server4"];
server2 -> server3;
server2 -> server4;
}
sentinel_system [label = "领头 Sentinel", shape = box, width = 5.0, height = 1.0];
sentinel_system -> server1 [style = dashed, label = "已下线", dir = none];
edge [label = "监视", dir = none];
sentinel_system -> server2;
sentinel_system -> server3;
sentinel_system -> server4;
}](_images/graphviz-5aa0e25464655bd036662f49dc4fc00644e4b801.png)
![digraph {
label = "\n 图 16-26 server1 被设置为新主服务器的从服务器";
subgraph cluster_servers {
style = invis;
node [shape = circle, width = 1.2];
edge [dir = none];
server1 [label = "server1", shape = circle, style = dashed];
server2 [label = "server2", shape = doublecircle];
server3 [label = "server3"];
server4 [label = "server4"];
server2 -> server1 [style = dashed];
server2 -> server3;
server2 -> server4;
}
sentinel_system [label = "Sentinel 系统", shape = box, width = 5.0, height = 1.0];
edge [dir = none];
sentinel_system -> server1 [style = dashed, label = "已下线"];
edge [label = "监视"];
sentinel_system -> server2;
sentinel_system -> server3;
sentinel_system -> server4;
}](_images/graphviz-077c570250a5be513411c91f510912fb67044a85.png)
![digraph {
label = "\n 图 16-27 server1 重新上线并成为 server2 的从服务器";
subgraph cluster_servers {
style = invis;
node [shape = circle, width = 1.2];
edge [dir = none];
server1 [label = "server1"];
server2 [label = "server2", shape = doublecircle];
server3 [label = "server3"];
server4 [label = "server4"];
server2 -> server1;
server2 -> server3;
server2 -> server4;
}
sentinel_system [label = "Sentinel 系统", shape = box, width = 5.0, height = 1.0];
edge [label = "监视", dir = none];
sentinel_system -> server1;
sentinel_system -> server2;
sentinel_system -> server3;
sentinel_system -> server4;
}](_images/graphviz-5f855165d6b42d40d2dcf9c9ab3c8ddcea5a5d5a.png)
第 17 章： 集群¶
![digraph {
label = "\n 图 17-1 三个独立的节点";
node [shape = circle];
subgraph cluster_a {
label = "集群";
style = dashed;
7000;
}
subgraph cluster_b {
label = "集群";
style = dashed;
7001;
}
subgraph cluster_c {
label = "集群";
style = dashed;
7002;
}
}](_images/graphviz-48a6e832e37169c30c009a0cb16bd028d3ed804c.png)
![digraph {
label = "\n 图 17-2 节点 7000 和 7001 进行握手";
rankdir = LR;
node [shape = circle];
subgraph cluster_a {
label = "集群";
style = dashed;
7000;
}
subgraph cluster_b {
label = "集群";
style = dashed;
7001;
}
subgraph cluster_c {
label = "集群";
style = dashed;
7002;
}
7000 -> 7001 [label = "握手"];
7000 -> 7001 [dir = back, label = "响应握手"];
}](_images/graphviz-c8a86ea8adabce15d5ef2568150a94d7c13d5b77.png)
![digraph {
label = "\n 图 17-3 握手成功的 7000 与 7001 处于同一个集群";
rankdir = LR;
node [shape = circle];
subgraph cluster_a {
label = "集群";
style = dashed;
7000;
7001;
7000 -> 7001 [style = invis];
}
subgraph cluster_c {
label = "集群";
style = dashed;
7002;
}
}](_images/graphviz-db7f193bfe0cb77ea8a6776b9d48c8a47c5adf39.png)
![digraph {
label = "\n 图 17-4 节点 7000 与节点 7002 进行握手";
rankdir = LR;
node [shape = circle];
subgraph cluster_a {
label = "集群";
style = dashed;
7000;
7001;
7000 -> 7001 [style = invis];
}
subgraph cluster_c {
label = "集群";
style = dashed;
7002;
}
7000 -> 7002 [label = "握手"];
7000 -> 7002 [dir = back, label = "响应握手"];
}](_images/graphviz-c2fcdadc8bab38040bc9a258e3db88c6bed5a642.png)
![digraph {
label = "\n 图 17-5 握手成功的三个节点处于同一个集群";
rankdir = LR;
subgraph cluster_a {
label = "集群";
style = dashed;
node [shape = circle];
7000;
7002;
7001;
edge [style = invis];
7000 -> 7001;
7000 -> 7002;
}
}](_images/graphviz-2203fc9c03899a525ad8f02ea4dd16035dd4b6cc.png)
![digraph {
label = "\n 图 17-7 节点 7000 创建的 clusterState 结构";
rankdir = LR;
//
node [shape = record];
clusterState [label = " <head> clusterState | <myself> myself | currentEpoch \n 0 | state \n REDIS_CLUSTER_FAIL | size \n 0 | <nodes> nodes | ... "];
nodes [label = " <head> nodes | <0> \"5154...2939\" | <1> \"68ee...f2ff\" | <2> \"9dfb...5c26\" "];
node7000 [label = " <head> clusterNode | name \n \"5154...2939\" | flags \n REDIS_NODE_MASTER | configEpoch \n 0 | ip \n \"127.0.0.1\" | port \n 7000 | ... "];
node7001 [label = " <head> clusterNode | name \n \"68ee...f2ff\"| flags \n REDIS_NODE_MASTER | configEpoch \n 0 | ip \n \"127.0.0.1\" | port \n 7001 | ... "];
node7002 [label = " <head> clusterNode | name \n \"9dfb...5c26\"| flags \n REDIS_NODE_MASTER | configEpoch \n 0 | ip \n \"127.0.0.1\" | port \n 7002 | ... "];
//link7000 [label = " <head> clusterLink | ctime | fd | sndbuf | rcvbuf "];
clusterState:myself -> node7000:head;
clusterState:nodes -> nodes:head;
nodes:0 -> node7000:head;
nodes:1 -> node7001:head;
nodes:2 -> node7002:head;
}](_images/graphviz-9918e854bcc7de909d8ddac20b76618568e75723.png)
![digraph {
label = "\n 图 17-8 节点的握手过程";
rankdir = LR;
splines = polyline;
//
node [shape = box, height = 2];
client [label = "客\n户\n端"];
A [label = "节\n点\nA"];
B [label = "节\n点\nB"];
//
client -> A [label = "发送命令 \n CLUSTER MEET \n <B_ip> <B_port>"];
A -> B [label = "发送 MEET 消息"];
A -> B [dir = back, label = "\n返回 PONG 消息"];
A -> B [label = "\n返回 PING 消息"];
}](_images/graphviz-c3f19dd40ff14db891e429fb5d9e9a80182aa3ca.png)
槽指派¶
图 17-9 展示了一个 slots 数组示例：
这个数组索引 0 至索引 7 上的二进制位的值都为 1 ，
其余所有二进制位的值都为 0 ，
这表示节点负责处理槽 0 至槽 7 。
![digraph {
label = "\n 图 17-9 一个 slots 数组示例";
node [shape = record];
slots [label = " { 字节 | 索引 | 值 } | { slots[0] | {{ 0 | 1} | { 1 | 1} | { 2 | 1 } | { 3 | 1} | { 4 | 1 } | { 5 | 1 } | { 6 | 1 } | { 7 | 1 } }} | { slots[1] ~ slots[2047] | {{ 8 | 0 } | { 9 | 0 } | { 10 | 0 } | { 11 | 0 } | { 12 | 0 } | { ... | ... } | { 16381 | 0 } | { 16382 | 0 } | { 16383 | 0 } }} "];
}](_images/graphviz-f4e2ea85d79cfa546d741dfc6eb759c914b8238c.png)
图 17-10 展示了另一个 slots 数组示例：
这个数组索引 1 、 3 、 5 、 8 、 9 、 10 上的二进制位的值都为 1 ，
而其余所有二进制位的值都为 0 ，
这表示节点负责处理槽 1 、 3 、 5 、 8 、 9 、 10 。
![digraph {
label = "\n 图 17-10 另一个 slots 数组示例";
node [shape = record];
slots [label = " { 字节 | 索引 | 值 } | { slots[0] | {{ 0 | 0} | { 1 | 1} | { 2 | 0 } | { 3 | 1} | { 4 | 0 } | { 5 | 1 } | { 6 | 0 } | { 7 | 0 } }} | { slots[1] | {{ 8 | 1} | { 9 | 1 } | { 10 | 1 } | { 11 | 0 } | { 12 | 0 } | { 13 | 0 } | { 14 | 0 } | { 15 | 0 }}} | { ... | ... | ... } | { slots[2047] | { { ... | ... } | { 16382 | 0 } | { 16383 | 0 }} } "];
}](_images/graphviz-d14f3a0591ae484be99a64ea07ce44137cee95c9.png)
节点之间互相传递槽指派信息的过程。
![digraph {
label = "\n 图 17-11 7000 告知 7001 和 7002 自己负责处理的槽";
rankdir = LR;
subgraph cluster_a {
label = "集群";
style = dashed;
node [shape = circle];
7000;
7002;
7001;
edge [style = dashed, label = "\n我负责处理\n槽 0 至槽 5000"];
7000 -> 7001;
7000 -> 7002;
}
}](_images/graphviz-9d36fbbb3e36a00f4dbf5726d3454b32db9af9be.png)
![digraph {
label = "\n 图 17-12 7001 告知 7000 和 7002 自己负责处理的槽";
subgraph cluster_a {
label = "集群";
style = dashed;
node [shape = circle];
7000;
7002;
7001;
edge [style = dashed, label = "我负责处理\n槽 5001 至槽 10000"];
7001 -> 7000;
7001 -> 7002;
}
}](_images/graphviz-385e8e971ed3ff3d0de104e8e39953ea32541eb6.png)
![digraph {
label = "\n 图 17-13 7002 告知 7000 和 7001 自己负责处理的槽";
rankdir = BT;
subgraph cluster_a {
label = "集群";
labelloc = "b";
style = dashed;
node [shape = circle];
7000;
7002;
7001;
edge [style = dashed, label = "我负责处理\n槽 10001 至槽 16383"];
7002 -> 7000;
7002 -> 7001;
}
}](_images/graphviz-4982f6dbedb170f9a0aa82d981f3618088a0914b.png)
clusterState 结构的 slots 数组示例。
![digraph {
label = "\n 图 17-14 clusterState 结构的 slots 数组";
rankdir = LR;
node [shape = record];
clusterState [label = " clusterState | ... | <slots> slots | ... "];
slots [label = " <head> clusterNode*[16384] | <0> 0 | <1> 1 | <2> ... | <5000> 5000 | <5001> 5001 | <5002> 5002 | <5003> ... | <10000> 10000 | <10001> 10001 | <10002> 10002 | <10003> ... | <16383> 16383 "];
node7000 [label = " <head> clusterNode | ... | ip \n \"127.0.0.1\" | port \n 7000 | ... "];
node7001 [label = " <head> clusterNode | ... | ip \n \"127.0.0.1\" | port \n 7001 | ... "];
node7002 [label = " <head> clusterNode | ... | ip \n \"127.0.0.1\" | port \n 7002 | ... "];
slots:0 -> node7000:head;
slots:1 -> node7000:head;
slots:2 -> node7000:head;
slots:5000 -> node7000:head;
slots:5001 -> node7001:head;
slots:5002 -> node7001:head;
slots:5003 -> node7001:head;
slots:10000 -> node7001:head;
slots:10001 -> node7002:head;
slots:10002 -> node7002:head;
slots:10003 -> node7002:head;
slots:16383 -> node7002:head;
clusterState:slots -> slots:head;
}](_images/graphviz-dbc5b814af27f83c1ce4731898f00bbbc10ca688.png)
![digraph {
label = "\n 图 17-18 判断客户端是否需要转向的流程";
node [shape = box];
client_send_command [label = "客户端向节点发送数据库键命令", width = 7];
get_slot_number [label = "节点计算键属于哪个槽"];
node_handle_right_slot_or_not [label = "当前节点就是\n负责处理键所在槽的节点？", shape = diamond];
execute_command [label = "节点执行命令"];
return_moved [label = "节点向客户端返回一个\n MOVED 错误"];
client_redirect [label = "客户端根据 MOVED 错误提供的信息\n转向至正确的节点"];
//
client_send_command -> get_slot_number;
get_slot_number -> node_handle_right_slot_or_not;
node_handle_right_slot_or_not -> execute_command [label = "是"];
node_handle_right_slot_or_not -> return_moved [label = "不是"];
return_moved -> client_redirect;
client_redirect -> client_send_command [label = "重试"];
}](_images/graphviz-6f36d23c96de411c52b064521b087ba8bda9ccd8.png)
![digraph {
label = "\n 图 17-20 节点 7000 向客户端返回 MOVED 错误";
rankdir = LR;
splines = polyline;
node [shape = box];
client [label = "客户端", height = 2.5];
node7000 [label = "节点 7000", height = 2.5];
//
client -> node7000 [label = "\nSET msg \"happy new year!\""];
client -> node7000 [dir = back, label = "\nMOVED 6257 127.0.0.1:7001"];
}](_images/graphviz-fd118bc1e5d00ab3f6ed6f1fd15660454180462e.png)
![digraph {
label = "\n 图 17-21 客户端根据 MOVED 错误的指示转向至节点 7001";
rankdir = LR;
splines = polyline;
node [shape = box];
client [label = "客户端", height = 2.5];
node7001 [label = "节点 7001", height = 2.5];
//
client -> node7001 [label = "\n转向"];
client -> node7001 [label = "\nSET msg \"happy new year!\""];
client -> node7001 [dir = back, label = "\nOK"];
}](_images/graphviz-f493afd6f5dd84caa1c8815491878c48fa8797af.png)
![digraph {
rankdir = LR;
node [shape = record, width = "0.5"];
//
l [label = " <header> header | <tail> tail | level \n 5 | length \n 3 "];
subgraph cluster_nodes {
style = invisible;
header [label = " <l32> L32 | ... | <l5> L5 | <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 "];
bw_null [label = "NULL", shape = plaintext];
level_null [label = "NULL", shape = plaintext];
A [label = " <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 | <backward> BW | 1337.0 | StringObject \n \"book\" "];
B [label = " <l2> L2 | <l1> L1 | <backward> BW | 2022.0 | StringObject \n \"date\" "];
C [label = " <l5> L5 | <l4> L4 | <l3> L3 | <l2> L2 | <l1> L1 | <backward> BW | 3347.0 | StringObject \n \"lst\" "];
}
subgraph cluster_nulls {
style = invisible;
n1 [label = "NULL", shape = plaintext];
n2 [label = "NULL", shape = plaintext];
n3 [label = "NULL", shape = plaintext];
n4 [label = "NULL", shape = plaintext];
n5 [label = "NULL", shape = plaintext];
}
//
l:header -> header;
l:tail -> C;
/*
// 移除连接线的 span 分值
header:l32 -> level_null [label = "0"];
header:l5 -> C:l5 [label = "3"];
header:l4 -> A:l4 [label = "1"];
header:l3 -> A:l3 [label = "1"];
header:l2 -> A:l2 [label = "1"];
header:l1 -> A:l1 [label = "1"];
A:l4 -> C:l4 [label = "2"];
A:l3 -> C:l3 [label = "2"];
A:l2 -> B:l2 [label = "1"];
A:l1 -> B:l1 [label = "1"];
B:l2 -> C:l2 [label = "1"];
B:l1 -> C:l1 [label = "1"];
C:l5 -> n5 [label = "0"];
C:l4 -> n4 [label = "0"];
C:l3 -> n3 [label = "0"];
C:l2 -> n2 [label = "0"];
C:l1 -> n1 [label = "0"];
*/
header:l32 -> level_null;
header:l5 -> C:l5;
header:l4 -> A:l4;
header:l3 -> A:l3;
header:l2 -> A:l2;
header:l1 -> A:l1;
A:l4 -> C:l4;
A:l3 -> C:l3;
A:l2 -> B:l2;
A:l1 -> B:l1;
B:l2 -> C:l2;
B:l1 -> C:l1;
C:l5 -> n5;
C:l4 -> n4;
C:l3 -> n3;
C:l2 -> n2;
C:l1 -> n1;
bw_null -> A:backward -> B:backward -> C:backward [dir = back];
label = "\n 图 17-23 节点 7000 的 slots_to_keys 跳跃表";
}](_images/graphviz-7d8c052c7993e1861781c7f3191c28d8aca8318b.png)
![digraph {
label = "\n 图 17-24 迁移键的过程";
rankdir = LR;
splines = polyline;
//
node [shape = box, height = 3];
client [label = "redis-trib"];
source [label = "源\n节\n点"];
target [label = "目\n标\n节\n点"];
//
client -> source [label = "1) 发送命令 \n CLUSTER GETKEYSINSLOT <slot> <count>"];
client -> source [dir = back, label = "\n 2) 返回最多 count 个属于槽 slot 的键"];
client -> source [label = "\n 3) 对于每个返回键\n向源节点发送一个 MIGRATE 命令"];
source -> target [label = "\n 4) 根据 MIGRATE 命令的指示 \n 将键迁移至目标节点"];
}](_images/graphviz-fba74127c3849e540cea49200ee809b01f8c8a27.png)
![digraph {
label = "\n 图 17-25 对槽 slot 进行重新分片的过程"
node [shape = box]
start [label = "开始对槽 slot 进行重新分片"]
send_importing_to_target [label = "目标节点准备导入槽 slot 的键值对"];
send_migrating_to_source [label = "源节点准备迁移槽 slot 的键值对"];
start -> send_importing_to_target -> send_migrating_to_source;
contain_slot_key_or_not [shape = diamond, label = "源节点是否保存了\n属于槽 slot 的键？"]
migrate [label = "将这些键\n全部迁移至目标节点"]
assign [label = "将槽 slot 指派给目标节点"]
done [label = "完成对槽 slot 的重新分片"]
send_migrating_to_source -> contain_slot_key_or_not
contain_slot_key_or_not -> migrate [label = "是"]
migrate -> assign
contain_slot_key_or_not -> assign [label = "否"]
assign -> done
}](_images/graphviz-fe3255f5de0cbab6f74ac113827dcf4f34ea65fe.png)
ASK 错误¶
源节点判断是否需要向客户端发送 ASK 错误的整个过程。
![digraph {
label = "\n 图 17-26 判断是否发送 ASK 错误的过程";
//
node [shape = box];
send_command [label = "客户端向源节点发送关于键 key 的命令"];
key_in_or_not [label = "键 key 是否存在于\n源节点的数据库？", shape = diamond];
execute_command [label = "节点执行客户端发送的命令"];
reshaing_or_not [label = "节点正在迁移槽 i ？", shape = diamond];
ask_redirect [label = "向客户端返回 ASK 错误"];
//
send_command -> key_in_or_not;
key_in_or_not -> execute_command [label = "是"];
key_in_or_not -> reshaing_or_not [label = "否"];
reshaing_or_not -> ask_redirect [label = "是\n键 key 有可能在目标节点"];
reshaing_or_not -> execute_command [label = "否\n键 key 不存在"];
}](_images/graphviz-e2c71f49318a6636a74534d4517ffa173c27dae0.png)
importing_slots_from 结构以及 migrating_slots_to 结构的示例。
![digraph {
label = "\n 图 17-27 节点 7003 的 importing_slots_from 数组";
rankdir = LR;
//
node [shape = record];
clusterState [label = " clusterState | ... | <slots> importing_slots_from | ... "];
slots [label = " <head> clusterNode*[16384] | <0> 0 | <1> 1 | <2> 2 | <3> ... | <16198> 16198 | <15002> ... | <16381> 16381 | <16382> 16382 | <16383> 16383 "];
node7002 [label = " <head> clusterNode | ... | ip \n \"127.0.0.1\" | port \n 7002 | ... "];
node [shape = plaintext, label = "NULL"];
//
slots:0 -> null0;
slots:1 -> null1;
slots:2 -> null2;
slots:16198 -> node7002:head [minlen = 2];
slots:16381 -> null16381;
slots:16382 -> null16382;
slots:16383 -> null16383;
clusterState:slots -> slots:head;
}](_images/graphviz-3065976827e7ea7bacc5b89104167644953d14cb.png)
![digraph {
label = "\n 图 17-28 节点 7002 的 migrating_slots_to 数组";
rankdir = LR;
//
node [shape = record];
clusterState [label = " clusterState | ... | <slots> migrating_slots_to | ... "];
slots [label = " <head> clusterNode*[16384] | <0> 0 | <1> 1 | <2> 2 | <3> ... | <16198> 16198 | <15002> ... | <16381> 16381 | <16382> 16382 | <16383> 16383 "];
node7003 [label = " <head> clusterNode | ... | ip \n \"127.0.0.1\" | port \n 7003 | ... "];
node [shape = plaintext, label = "NULL"];
//
slots:0 -> null0;
slots:1 -> null1;
slots:2 -> null2;
slots:16198 -> node7003:head [minlen = 2];
slots:16381 -> null16381;
slots:16382 -> null16382;
slots:16383 -> null16383;
clusterState:slots -> slots:head;
}](_images/graphviz-ed29e688b1313357de5bffdce9f6e021cd3c7f7e.png)
客户端根据 ASK 错误进行转向的过程。
![digraph {
label = "\n 图 17-29 客户端接收到节点 7002 返回的 ASK 错误";
rankdir = LR;
splines = polyline;
//
node [shape = box, height = 2];
client [label = "客户端"];
node7002 [label = "节点 7002"];
//
client -> node7002 [label = "GET \"love\""];
client -> node7002 [dir = back, label = "\nASK 16198 127.0.0.1:7003"];
}](_images/graphviz-33ecbe4574e08d8373be9d7d84f21a3d0ec950bb.png)
![digraph {
label = "\n 图 17-30 客户端转向至节点 7003";
rankdir = LR;
splines = polyline
//
node [shape = box, height = 3];
client [label = "客户端"];
node7003 [label = "节点 7003"];
//
client -> node7003 [label = "转向"];
client -> node7003 [label = "ASKING"];
client -> node7003 [label = "\n GET \"love\""];
client -> node7003 [dir = back, label = "\n\"you get the key 'love'\""];
}](_images/graphviz-75e479adc85e31d1d84e0e00d53a954bd23c7f16.png)
节点判断是否执行客户端命令的过程。
![digraph {
label = "\n 图 17-31 节点判断是否执行客户端命令的过程";
node [shape = box];
//
send_command [label = "客户端向节点发送关于槽 i 的命令"];
node_handle_slot_or_not [shape = diamond, label = "槽 i 是否指派给了节点？"];
exec_command [label = "节点执行客户端发送的命令"];
importing_slot_or_not [shape = diamond, label = "节点是否正在导入槽 i ？"];
client_get_asking_flag_or_not [shape = diamond, label = "客户端是否带有 \n ASKING 标识？"];
return_moved [label = "节点向客户端返回 MOVED 命令"];
//
send_command -> node_handle_slot_or_not;
node_handle_slot_or_not -> exec_command [label = "是"];
node_handle_slot_or_not -> importing_slot_or_not [label = "否"];
importing_slot_or_not -> client_get_asking_flag_or_not [label = "是"];
client_get_asking_flag_or_not -> exec_command [label = "是"];
importing_slot_or_not -> return_moved [label = "否"];
client_get_asking_flag_or_not -> return_moved [label = "否"];
}](_images/graphviz-b5c4a372c2e4808f4b355402bb92993399b93b1a.png)
![digraph {
label = "\n 图 17-32 设置节点 7004 和节点 7005 成为节点 7000 的从节点";
rankdir = LR;
subgraph cluster_a {
label = "集群";
style = dashed;
node [shape = doublecircle]
7000;
7001;
7002;
7003;
node [shape = circle]
7005;
7004;
edge [dir = back, label = "复制"]
7000 -> 7004
7000 -> 7005
edge [style = invis, label = ""]
7002 -> 7003
}
}](_images/graphviz-6524fa7af415bc0a44b4a758ea77d11dd2636705.png)
![digraph {
label = "\n 图 17-33 节点 7004 成为新的主节点";
rankdir = LR;
subgraph cluster_a {
label = "集群";
style = dashed;
node [shape = doublecircle];
7000 [style = dashed]
7001;
7002;
7003;
7004;
node [shape = circle]
7005;
edge [dir = back, label = "复制"]
7004 -> 7005
edge [style = invis, label = ""]
7000 -> 7001
7002 -> 7003
}
}](_images/graphviz-fe0e19a121e5b75eb82ccacfa6215c26c0ae8e39.png)
![digraph {
label = "\n 图 17-34 重新上线的节点 7000 成为节点 7004 的从节点";
rankdir = LR;
subgraph cluster_a {
label = "集群";
style = dashed;
node [shape = doublecircle];
7001;
7002;
7003;
7004;
node [shape = circle]
7000
7005;
edge [dir = back, label = "复制"]
7004 -> 7005
7004 -> 7000
edge [style = invis, label = ""]
7001 -> 7002 -> 7003
}
}](_images/graphviz-9dc2a416a4fd1f6e3b43da2b134e40c706da600a.png)
![digraph {
label = "\n 图 17-38 节点 7000 的下线报告"
rankdir = LR
node [shape = record]
node7000 [label = " <head> clusterNode | ... | flags \n REDIS_NODE_MASTER \n & \n REDIS_NODE_PFAIL | ip \n \"127.0.0.1\" | port \n 7000 | <fail_reports> fail_reports | ... "]
node7002 [label = " <head> clusterNode | ... | flags \n REDIS_NODE_MASTER | ip \n \"127.0.0.1\" | port \n 7002 | ... "]
node7003 [label = " <head> clusterNode | ... | flags \n REDIS_NODE_MASTER | ip \n \"127.0.0.1\" | port \n 7003 | ... "]
report7002 [label = " <head> clusterNodeFailReport | <pnode> node | time \n 1390525039000"]
report7003 [label = " <head> clusterNodeFailReport | <pnode> node | time \n 1390525039321"]
node7000:fail_reports -> report7002:head -> report7003:head
report7002:pnode -> node7002:head
report7003:pnode -> node7003:head
}](_images/graphviz-1c0cfe14e966f5288e61b6e9ac43465aea156bde.png)
![digraph {
label = "\n 图 17-39 节点 7001 向集群广播 FAIL 消息"
rankdir = LR;
subgraph cluster_a {
label = "集群";
style = dashed;
node [shape = doublecircle]
7000 [style = dashed]
7001;
7002;
7003;
node [shape = circle]
7004;
7005;
edge [dir = back, label = "复制"]
7000 -> 7004
7000 -> 7005
edge [dir = forward, label = "发送 FAIL 消息"]
7001 -> 7002
7001 -> 7003
7001 -> 7004
7001 -> 7005
}
}](_images/graphviz-c591fae308f56fa399fa9e52156bd2a568b144bf.png)
消息¶
集群中的节点通过发送消息来将一个节点标记为下线的过程。
![digraph {
label = "\n 图 17-42 节点 7001 将节点 7000 标记为已下线";
node [shape = circle];
subgraph cluster_cluster {
label = "集群";
node7000 [label = "7000", style = dashed];
node7001 [label = "7001"];
node7002 [label = "7002"];
node7003 [label = "7003"];
node7001 -> node7000 [label = "标记为\n已下线"];
edge [style = invis];
node7001 -> node7002 [label = "发送 FAIL 消息"];
node7001 -> node7003 [label = "发送 FAIL 消息"];
style = dashed;
}
}](_images/graphviz-74e2b6c26627aedbdd10295cfddd6bf6ee29d9ac.png)
![digraph {
label = "\n 图 17-43 节点 7001 向集群广播 FAIL 消息";
node [shape = circle];
subgraph cluster_cluster {
label = "集群";
node7000 [label = "7000", style = dashed];
node7001 [label = "7001"];
node7002 [label = "7002"];
node7003 [label = "7003"];
node7001 -> node7000 [style = invis];
edge [label = "发送 \nFAIL 消息"];
node7001 -> node7002;
node7001 -> node7003;
style = dashed;
}
}](_images/graphviz-e2e030e0a517bddc4c8c542b6876efeed2469941.png)
![digraph {
label = "\n 图 17-44 节点 7002 和节点 7003 也将节点 7000 标记为已下线";
node [shape = circle];
subgraph cluster_cluster {
label = "集群";
node7003 [label = "7003"];
node7002 [label = "7002"];
node7001 [label = "7001"];
node7000 [label = "7000", style = dashed];
node7001 -> node7000 [style = invis];
edge [label = "标记为\n已下线"];
node7002 -> node7000;
node7003 -> node7000;
style = dashed;
}
}](_images/graphviz-c4408a7984bbcfdb233e87165044e609a7846ae2.png)
接收到 PUBLISH 命令的节点向集群中的其他节点发送 PUBLISH 消息。
![digraph {
label = "\n 图 17-45 接收到 PUBLISH 命令的节点 7000 向集群广播 PUBLISH 消息";
node [shape = circle];
rankdir = LR;
client [label = "客户端"];
subgraph cluster_cluster {
label = "集群";
node7003 [label = "7003"];
node7002 [label = "7002"];
node7001 [label = "7001"];
node7000 [label = "7000"];
edge [label = "发送 \n PUBLISH \n 消息"];
node7000 -> node7001;
node7000 -> node7002;
node7000 -> node7003;
style = dashed;
}
client -> node7000 [label = "发送 \n PUBLISH \n 命令"];
}](_images/graphviz-a6bed3355b74c4c1790c715812e50149bbec36c4.png)
PUBLISH 消息中包含的 clusterMsgDataPublish 结构示例。
![digraph {
label = "\n 图 17-46 clusterMsgDataPublish 结构示例";
node [shape = record];
rankdir = LR;
clusterMsgDataPublish [label = " clusterMsgDataPublish | channel_len \n 7 | message_len \n 5 | <bulk_data> bulk_data "];
bulk_data [label = " { 'n' | 'e' | 'w' | 's' | '.' | 'i' | 't' | 'h' | 'e' | 'l' | 'l' | 'o' } "];
clusterMsgDataPublish:bulk_data -> bulk_data;
}](_images/graphviz-0336c8bb5dab19b0a302faeb107db2e7a5f3d291.png)
第 18 章： 发布与订阅¶
客户端订阅频道。
![digraph {
label = "\n 图 18-1 news.it 频道和它的三个订阅者";
rankdir = BT;
//
news_it [label = "news.it 频道", shape = box, width = 3.0];
client_1 [label = "客户端 A"];
client_2 [label = "客户端 B"];
client_3 [label = "客户端 C"];
//
edge [label = "订阅"];
client_1 -> news_it;
client_2 -> news_it;
client_3 -> news_it;
}](_images/graphviz-25889daa26b8ba11043c7f08f5c96b6a0d7e1173.png)
客户端向频道发送消息， 消息被传递至各个订阅者。
![digraph {
label = "\n 图 18-2 向 news.it 频道发送消息";
//
publish [label = "PUBLISH \"news.it\" \"hello\"", shape = plaintext];
news_it [label = "news.it 频道", shape = box, width = 3.0];
client_1 [label = "客户端 A"];
client_2 [label = "客户端 B"];
client_3 [label = "客户端 C"];
//
edge [style = dashed];
publish -> news_it;
edge [label = "\"hello\""];
news_it -> client_1;
news_it -> client_2;
news_it -> client_3;
}](_images/graphviz-0c8815c9d27b05c73c8c67c5e8eb59c6cf5e2e3a.png)
客户端订阅模式。
![digraph {
label = "\n 图 18-3 频道和模式的订阅状态";
rankdir = BT;
//
news_et [label = "news.et 频道", shape = box, width = 3.0];
news_it [label = "news.it 频道", shape = box, width = 3.0];
news_iet [label = "news.[ie]t 模式", shape = hexagon, width = 3.0];
node [shape = ellipse];
client_1 [label = "客户端 A"];
client_2 [label = "客户端 B"];
client_3 [label = "客户端 C"];
client_4 [label = "客户端 D"];
//
client_1 -> news_it [label = "订阅"];
client_2 -> news_et [label = "订阅"];
news_iet -> news_et [dir = back, label = "匹配"];
news_iet -> news_it [dir = back, label = "匹配"];
edge [label = "订阅"];
client_3 -> news_iet;
client_4 -> news_iet;
}](_images/graphviz-e106e8482814f2397eceeccefc20cc1b7df7fee9.png)
客户端向频道发送消息， 消息被传递给正在订阅匹配模式的订阅者。
![digraph {
label = "\n 图 18-4 将消息发送给频道的订阅者和匹配模式的订阅者";
rankdir = BT;
//
news_et [label = "news.et 频道", shape = box, width = 3.0];
news_it [label = "news.it 频道", shape = box, width = 3.0];
news_iet [label = "news.[ie]t 模式", shape = hexagon, width = 3.0];
publish [label = "PUBLISH \"news.it\" \"hello\"", shape = plaintext];
node [shape = ellipse];
client_1 [label = "客户端 A"];
client_2 [label = "客户端 B"];
client_3 [label = "客户端 C"];
client_4 [label = "客户端 D"];
//
client_1 -> news_it [dir = back, label = "\"hello\"", style = dashed];
client_2 -> news_et [label = "订阅"];
news_iet -> news_et [dir = back, label = "匹配"];
news_iet -> news_it [dir = back, label = "匹配", style = dashed];
edge [dir = back, label = "\"hello\"", style = dashed];
client_3 -> news_iet;
client_4 -> news_iet;
news_it -> publish [dir = back, style = dashed, label =""];
}](_images/graphviz-f64be6f3116548c779e2357dae83bec87c04bd50.png)
另一个模式被匹配的例子。
![digraph {
label = "\n 图 18-5 将消息发送给频道的订阅者和匹配模式的订阅者";
rankdir = BT;
//
news_et [label = "news.et 频道", shape = box, width = 3.0];
news_it [label = "news.it 频道", shape = box, width = 3.0];
news_iet [label = "news.[ie]t 模式", shape = hexagon, width = 3.0];
publish [label = "PUBLISH \"news.et\" \"world\"", shape = plaintext];
node [shape = ellipse];
client_1 [label = "客户端 A"];
client_2 [label = "客户端 B"];
client_3 [label = "客户端 C"];
client_4 [label = "客户端 D"];
//
client_1 -> news_it [label = "订阅"];
client_2 -> news_et [dir = back, label = "\"world\"", style = dashed];
news_iet -> news_et [dir = back, label = "匹配", style = dashed];
news_iet -> news_it [dir = back, label = "匹配"];
edge [dir = back, label = "\"world\"", style = dashed];
client_3 -> news_iet;
client_4 -> news_iet;
news_et -> publish [dir = back, style = dashed, label =""];
}](_images/graphviz-c6b4b1ef3f52384cfcb880a270408fa7ccdbcb2a.png)
pubsub_channels 字典示例。
![digraph {
label = "\n 图 18-6 一个 pubsub_channels 字典示例";
rankdir = LR;
//
node [shape = record];
pubsub_channels [label = " pubsub_channels | <news_it> \"news.it\" | <news_sport> \"news.sport\" | <news_business> \"news.business\" ", height = 3, width = 2.2];
client_1 [label = "client-1"];
client_2 [label = "client-2"];
client_3 [label = "client-3"];
client_4 [label = "client-4"];
client5 [label = "client-5"];
client6 [label = "client-6"];
//
pubsub_channels:news_it -> client_1; client_1 -> client_2; client_2 -> client_3;
pubsub_channels:news_sport -> client_4;
pubsub_channels:news_business -> client5 -> client6;
}](_images/graphviz-a81ae64799855f0aa549cece1fd738475dcc4313.png)
pubsubPattern 结构示例。
![digraph {
label = "\n 图 18-10 pubsubPattern 结构示例";
rankdir = LR;
//
node [shape =record];
pubsubPattern [label = " pubsubPattern | client \n client-9 | pattern \n \"news.*\" "];
}](_images/graphviz-52b76393460eba28968c4ef6b5fc3b3ceba0ff40.png)
pubsub_patterns 链表的示例。
![digraph {
label = "\n 图 18-11 pubsub_patterns 链表示例";
rankdir = LR;
//
node [shape = record];
redisServer [label = "redisServer | ... | <pubsub_patterns> pubsub_patterns | ...", height = 2.2, width = 2.2];
all_music [label = " pubsubPattern | client \n client-7 | pattern \n \"music.*\" "];
all_book [label = " pubsubPattern | client \n client-8 | pattern \n \"book.*\" "];
all_news [label = " pubsubPattern | client \n client-9 | pattern \n \"news.*\" "];
//
redisServer:pubsub_patterns -> all_music;
all_music -> all_book;
all_book -> all_news;
}](_images/graphviz-c3da1c52931024fdcc850654a4f4e061312b1b33.png)
![digraph enque_or_execute {
label = "\n图 19-1 服务器判断命令是该入队还是该执行的过程";
node [shape = box];
//
command_in [label = "服务器接到来自客户端的命令"];
in_transaction_or_not [label = "这个客户端正处于事务状态？", shape = diamond];
not_exec_and_discard [label = "这个命令是否\nEXEC 、 DISCARD 、\nWATCH 或 MULTI ？", shape = diamond];
enqueu_command [label = "将命令放入事务队列"];
return_enqueued [label = "向客户端返回 QUEUED"];
exec_command [label = "执行这个命令"];
return_command_result [label = "向客户端返回命令的执行结果"];
//
command_in -> in_transaction_or_not;
in_transaction_or_not -> not_exec_and_discard [label = "是"];
not_exec_and_discard -> enqueu_command [label = "否"];
not_exec_and_discard -> exec_command [label = "是"];
in_transaction_or_not -> exec_command [label = "否"];
exec_command -> return_command_result;
enqueu_command -> return_enqueued;
}](_images/graphviz-80409479fc5a22a90d467a2f7c356ff3de00d6f7.png)
![digraph {
label = "\n 图 19-2 事务状态";
rankdir = LR;
node [shape = record];
//redisClient [label = " <head> redisClient | ... | <mstate> mstate | ... "];
multiState [label = " <head> multiState | <commands> commands | count \n 4 "];
commands [label = " <head> multiCmd[4] | <0> [0] | <1> [1] | <2> [2] | <3> [3] "];
multiCmd0 [label = " <head> multiCmd | <argv> argv | argc \n 3 | <cmd> cmd "];
multiCmd1 [label = " <head> multiCmd | <argv> argv | argc \n 2 | <cmd> cmd "];
multiCmd2 [label = " <head> multiCmd | <argv> argv | argc \n 3 | <cmd> cmd "];
multiCmd3 [label = " <head> multiCmd | <argv> argv | argc \n 2 | <cmd> cmd "];
//redisClient:mstate -> multiState:head;
multiState:commands -> commands:head;
commands:0 -> multiCmd0:head;
commands:1 -> multiCmd1:head;
commands:2 -> multiCmd2:head;
commands:3 -> multiCmd3:head;
argv0 [label = " robj*[3] | { StringObject \n \"SET\" | StringObject \n \"name\" | StringObject \n \"Practical Common Lisp\" } "];
cmd0 [label = " setCommand ", shape = plaintext];
multiCmd0:argv -> argv0;
multiCmd0:cmd -> cmd0;
argv1 [label = " robj*[2] | { StringObject \n \"GET\" | StringObject \n \"name\" } "];
cmd1 [label = " getCommand ", shape = plaintext];
multiCmd1:argv -> argv1;
multiCmd1:cmd -> cmd1;
argv2 [label = " robj*[3] | { StringObject \n \"SET\" | StringObject \n \"author\" | StringObject \n \"Peter Seibel\" } "];
cmd2 [label = " setCommand ", shape = plaintext];
multiCmd2:argv -> argv2;
multiCmd2:cmd -> cmd2;
argv3 [label = " robj*[2] | { StringObject \n \"GET\" | StringObject \n \"author\" } "];
cmd3 [label = " getCommand ", shape = plaintext];
multiCmd3:argv -> argv3;
multiCmd3:cmd -> cmd3;
}](_images/graphviz-0bdfab80796f3926377ca2512b422dc3361bd74a.png)
![digraph {
label = "\n 图 19-5 watched_keys 字典";
rankdir = LR;
node [shape = record];
//
watched_keys [label = "watched_keys | <name> \"name\" | <age> \"age\" | <address> \"address\" ", width = 2.0, height = 3.0];
//
name_c2 [label = "c2"];
address_c2 [label = "c2"];
name_c10086 [label = "c10086"];
age_c10086 [label = "c10086"];
//
watched_keys:name -> c1 -> name_c2 -> name_c10086;
watched_keys:age -> c3 -> age_c10086;
watched_keys:address -> address_c2 -> c4;
}](_images/graphviz-49e3cee37873c14e9a7d2d4d9071a668d2aa2cd5.png)
![digraph {
label = "\n 图 19-6 服务器判断是否执行事务的过程";
node [shape = box];
exec [label = "客户端向服务器发送 EXEC 命令"];
dirty_cas_or_not [label = "客户端的 \n REDIS_DIRTY_CAS \n 标识是否已经打开？", shape = diamond];
reject [label = "拒绝执行客户端提交的事务"];
ok [label = "执行客户端提交的事务"];
exec -> dirty_cas_or_not;
dirty_cas_or_not -> reject [label = "是"];
dirty_cas_or_not -> ok [label = "否"];
}](_images/graphviz-e0fa81234c07f8bbce33fcbeb51c630667a58e62.png)
第 20 章： Lua 脚本¶
![digraph {
label = "\n图 20-1 服务器状态中的 Lua 环境";
rankdir = LR;
node [shape = record];
server [label = "redisServer | ... | <lua> lua | ...", width = 2.0, height = 2.0];
lua [label = "Lua 环境", shape = circle];
server:lua -> lua;
}](_images/graphviz-41e00edf2cf2f55e7af0b403dd6019e90939b9c4.png)
Lua 环境协作组件¶
Lua 脚本执行 Redis 命令时的通讯步骤。
![digraph {
label = "\n图 20-2 Lua 脚本执行 Redis 命令时的通讯步骤";
rankdir = LR;
node [shape = record, height = 2.0];
splines = polyline;
//
lua [label = "L\nu\na\n环\n境"];
fake_client [label = "伪\n客\n户\n端"];
eval [label = "命\n令\n执\n行\n器"];
lua -> fake_client [label = "1) 传送 redis.call 函数\n想要执行的 Redis 命令"]
fake_client -> eval [label = "2) 将命令传给执行器执行"];
lua -> fake_client [dir = back, label = "\n4) 将命令结果传回给 Lua 环境"];
fake_client -> eval [dir = back, label = "\n3) 返回命令的执行结果"];
}](_images/graphviz-1df0a0a34bb204c0b0b05a78e3d943f3c9072a6b.png)
作为例子， 图 20-3 展示了 Lua 脚本在执行以下命令时：
redis> EVAL "return redis.call('DBSIZE')" 0
(integer) 10086
Lua 环境、伪客户端、命令执行器三者之间的通讯过程。
![digraph {
label = "\n图 20-3 Lua 脚本执行 DBSIZE 命令时的通讯步骤";
rankdir = LR;
node [shape = record, height = 2.0];
splines = polyline;
//
lua [label = "L\nu\na\n环\n境"];
fake_client [label = "伪\n客\n户\n端"];
eval [label = "命\n令\n执\n行\n器"];
lua -> fake_client [label = "1) 传送 DBSIZE 请求"]
fake_client -> eval [label = "2) 将 DBSIZE 命令传给执行器执行"];
lua -> fake_client [dir = back, label = "\n4) 将命令结果 10086 传回给 Lua 环境"];
fake_client -> eval [dir = back, label = "\n3) 返回命令的执行结果 10086"];
}](_images/graphviz-b9d78830d209f9489af2361b728cb1e5349bb9ec.png)
lua_scripts 字典示例。
![digraph {
label = "\n 图 20-4 lua_scripts 字典示例";
rankdir = LR;
node [shape = record];
//
lua_scripts [label = "lua_scripts | ... | <1> \"2f31ba2bb6d6a0f42cc159d2e2dad55440778de3\" | <2> \"a27e7e8a43702b7046d4f6a7ccf5b60cef6b9bd9\" | <3> \"4475bfb5919b5ad16424cb50f74d4724ae833e72\" | ... "];
node [shape = plaintext];
one [label = "\"return 'hi'\""];
two [label = "\"return 1+1\""];
three [label = "\"return 2*2\""];
lua_scripts:1 -> one;
lua_scripts:2 -> two;
lua_scripts:3 -> three;
}](_images/graphviz-0202a0b9f583aaab80234c905ba9f9b877a69295.png)
![digraph {
label = "\n图 20-8 带有超时处理钩子的脚本的执行过程";
node [shape = box];
start_script [label = "开始执行脚本", width = 3.5];
finish_or_not [label = "脚本执行完毕？", shape = diamond];
finish [label = "返回执行结果"];
overtime_or_not [label = "定期调用钩子\n检查脚本\n是否已超时运行？", shape = diamond];
kill_or_shutdown_arrive_or_not [label = "有 SCRIPT KILL\n或者\nSHUTDOWN NOSAVE\n到达？", shape = diamond];
stop_script [label = "执行 SCRIPT KILL \n 或者 SHUTDOWN"];
keep_running [label = "继续执行脚本"];
//
start_script -> finish_or_not;
finish_or_not -> finish [label = "是"];
finish_or_not -> overtime_or_not [label = "否"];
overtime_or_not -> kill_or_shutdown_arrive_or_not [label = "是"];
overtime_or_not -> keep_running [label = "否"];
kill_or_shutdown_arrive_or_not -> stop_script [label = "是"];
kill_or_shutdown_arrive_or_not -> keep_running [label = "否"];
keep_running -> finish_or_not;
}](_images/graphviz-3b0c394f6034e4687623d85d85488802781242d3.png)
![digraph {
label = "\n 图 20-9 将脚本命令传播给从服务器";
rankdir = LR;
//
node [shape = circle, width = 1.0];
client [label = "客户端", width = 1.3];
master [label = "主服务器", width = 1.3];
slave1 [label = "从服务器 1"];
slave2 [label = "从服务器 2"];
more [label = "...", shape = plaintext];
slaveN [label = "从服务器 N"];
//
edge [label = "EVAL \n 或者 \n SCRIPT FLUSH \n 或者 \n SCRIPT LOAD"];
client -> master;
master -> slave1;
master -> slave2;
master -> more;
master -> slaveN;
}](_images/graphviz-3dd73e3a33d3296432d160fc0ce47ffc4a17aa68.png)
![digraph {
label = "\n 图 20-12 主服务器判断传播 EVAL 还是 EVALSHA 的过程";
node [shape = box];
command [label = " 主服务器在本机执行完命令 \n EVALSHA <sha1> <numkeys> [key ...] [arg ...] "];
sha1_exists_in_scriptcache_or_not [label = "校验和 sha1 是否存在于 \n repl_scriptcache_dict 字典？", shape = diamond];
propagate_evalsha [label = "传播 \n EVALSHA <sha1> <numkeys> [key ...] [arg ...]"];
convert_evalsha_to_eval [label = "将 EVALSHA 命令转换成等价的 EVAL 命令"];
propagate_eval [label = "传播 \n EVAL <script> <numkeys> [key ...] [arg ...]"];
add_sha1_to_scriptcache [label = "将 sha1 添加到 \n repl_scriptcache_dict 字典"];
//
command -> sha1_exists_in_scriptcache_or_not;
sha1_exists_in_scriptcache_or_not -> propagate_evalsha [label = "是"];
sha1_exists_in_scriptcache_or_not -> convert_evalsha_to_eval [label = "否"];
convert_evalsha_to_eval -> propagate_eval;
propagate_eval -> add_sha1_to_scriptcache;
}](_images/graphviz-a7e2ff0ea8e7182c4548ed44a512dea0fd77f34c.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | u } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | u } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | u } } "];
}
label = "\n 图 21-1 命令为排序 numbers 列表而创建的数组";
}](_images/graphviz-22a4a72a7775327e441c1b6c45780ada43499e93.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_numbers {
label = "numbers 链表"
style = dashed;
one [label = "StringObject \n \"1\""];
two [label = "StringObject \n \"2\""];
three [label = "StringObject \n \"3\""];
three -> one -> two;
}
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | u } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | u } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | u } } "];
}
array:obj0 -> three;
array:obj1 -> one;
array:obj2 -> two;
label = "\n 图 21-2 将 obj 指针指向列表的各个项";
}](_images/graphviz-f712f7955cf02d331aa0d749b787fd34d224d554.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_numbers {
label = "numbers 链表"
style = dashed;
one [label = "StringObject \n \"1\""];
two [label = "StringObject \n \"2\""];
three [label = "StringObject \n \"3\""];
three -> one -> two;
}
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | u.score \n 3.0 } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | u.score \n 1.0 } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | u.score \n 2.0 } } "];
}
array:obj0 -> three;
array:obj1 -> one;
array:obj2 -> two;
label = "\n 图 21-3 设置数组项的 u.score 属性";
}](_images/graphviz-62a7f2ef499dbbd701168223a41fecbb1afbaa47.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_numbers {
label = "numbers 链表"
style = dashed;
one [label = "StringObject \n \"1\""];
two [label = "StringObject \n \"2\""];
three [label = "StringObject \n \"3\""];
three -> one -> two;
}
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | u.score \n 1.0 } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | u.score \n 2.0 } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | u.score \n 3.0 } } "];
}
array:obj0 -> one;
array:obj1 -> two;
array:obj2 -> three;
label = "\n 图 21-4 排序后的数组";
}](_images/graphviz-9cfef9e2ba5ce22032a12b9c9632854b94cdf6cb.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_fruits {
label = "fruits 集合";
style = dashed;
apple [label = "StringObject \n \"apple\""];
banana [label = "StringObject \n \"banana\""];
cherry [label = "StringObject \n \"cherry\""];
apple -> cherry -> banana [style = invis];
}
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | u } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | u } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | u } } "];
}
array:obj0 -> apple;
array:obj1 -> cherry;
array:obj2 -> banana;
label = "\n 图 21-5 将 obj 指针指向集合的各个元素";
}](_images/graphviz-f1e2ca8f10a3809ad0f30d2401c5e676c136cab9.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_fruits {
label = "fruits 集合";
style = dashed;
apple [label = "StringObject \n \"apple\""];
banana [label = "StringObject \n \"banana\""];
cherry [label = "StringObject \n \"cherry\""];
apple -> cherry -> banana [style = invis];
}
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | u } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | u } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | u } } "];
}
array:obj0 -> apple;
array:obj1 -> banana;
array:obj2 -> cherry;
label = "\n 图 21-6 按集合元素进行排序后的数组";
}](_images/graphviz-722130c084517ab4cf2acd4bcc4b791d63ca4a61.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_numbers {
label = "numbers 链表"
style = dashed
one [label = "StringObject \n \"1\""];
two [label = "StringObject \n \"2\""];
three [label = "StringObject \n \"3\""];
three -> one -> two;
}
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | u.score \n 1.0 } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | u.score \n 2.0 } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | u.score \n 3.0 } } "];
}
array:obj0 -> one;
array:obj1 -> two;
array:obj2 -> three;
label = "\n 图 21-7 执行升序排序的数组";
}](_images/graphviz-c0bafde800e80b9431cf238c5b1ce3448d4b67ce.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_numbers {
label = "numbers 链表"
style = dashed;
one [label = "StringObject \n \"1\""];
two [label = "StringObject \n \"2\""];
three [label = "StringObject \n \"3\""];
three -> one -> two;
}
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | u.score \n 3.0 } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | u.score \n 2.0 } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | u.score \n 1.0 } } "];
}
array:obj0 -> three;
array:obj1 -> two;
array:obj2 -> one;
label = "\n 图 21-8 执行降序排序的数组";
}](_images/graphviz-a423e61a9781f04afae9582bc9e9dda5dd6933d2.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_fruits {
label = "fruits 集合";
style = dashed;
apple [label = "StringObject \n \"apple\""];
banana [label = "StringObject \n \"banana\""];
cherry [label = "StringObject \n \"cherry\""];
apple -> cherry -> banana [style = invis];
}
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | u } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | u } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | u } } "];
}
array:obj0 -> apple;
array:obj1 -> cherry;
array:obj2 -> banana;
label = "\n 图 21-9 将 obj 指针指向集合的各个元素";
}](_images/graphviz-cb92bf7952851453d485000ebbfa4170bfc4bcc7.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_fruits {
label = "fruits 集合";
style = dashed;
apple [label = "StringObject \n \"apple\""];
banana [label = "StringObject \n \"banana\""];
cherry [label = "StringObject \n \"cherry\""];
apple -> cherry -> banana [style = invis];
}
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | u.score \n 8.0 } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | u.score \n 7.0 } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | u.score \n 5.5 } } "];
}
array:obj0 -> apple;
array:obj1 -> cherry;
array:obj2 -> banana;
label = "\n 图 21-10 根据权重键的值设置数组项的 u.score 属性";
}](_images/graphviz-dde4764d3a639aec7b42f6a5e3ea123ba03fd983.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_fruits {
label = "fruits 集合";
style = dashed;
apple [label = "StringObject \n \"apple\""];
banana [label = "StringObject \n \"banana\""];
cherry [label = "StringObject \n \"cherry\""];
apple -> cherry -> banana [style = invis];
}
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | u.score \n 5.5 } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | u.score \n 7.0 } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | u.score \n 8.0 } } "];
}
array:obj0 -> banana;
array:obj1 -> cherry;
array:obj2 -> apple;
label = "\n 图 21-11 根据 u.score 属性进行排序之后的数组";
}](_images/graphviz-f02493e0d145bc8d64ab520d1fb37642d8cbceba.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_fruits {
label = "fruits 集合";
style = dashed;
apple [label = "StringObject \n \"apple\""];
banana [label = "StringObject \n \"banana\""];
cherry [label = "StringObject \n \"cherry\""];
apple -> cherry -> banana [style = invis];
}
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | u } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | u } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | u } } "];
}
array:obj0 -> apple;
array:obj1 -> cherry;
array:obj2 -> banana;
label = "\n 图 21-12 将 obj 指针指向集合的各个元素";
}](_images/graphviz-04597b79beabd7ff21f6feb147a5ec0874a3ad61.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_fruits {
label = "fruits 集合";
style = dashed;
apple [label = "StringObject \n \"apple\""];
banana [label = "StringObject \n \"banana\""];
cherry [label = "StringObject \n \"cherry\""];
apple -> cherry -> banana [style = invis];
}
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | <cmpobj0> u.cmpobj } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | <cmpobj1> u.cmpobj } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | <cmpobj2> u.cmpobj } } "];
}
array:obj0 -> apple;
array:obj1 -> cherry;
array:obj2 -> banana;
apple_id [label = "StringObject \n \"FRUIT-25\""];
banana_id [label = "StringObject \n \"FRUIT-79\""];
cherry_id [label = "StringObject \n \"FRUIT-13\""];
array:cmpobj0 -> apple_id;
array:cmpobj1 -> cherry_id;
array:cmpobj2 -> banana_id;
label = "\n 图 21-13 将 u.cmpobj 指针指向权重键";
}](_images/graphviz-6b823356a83604f812ee6f2f8c758bbc7572183e.png)
![digraph {
rankdir = LR;
node [shape = record];
subgraph cluster_fruits {
label = "fruits 集合";
style = dashed;
apple [label = "StringObject \n \"apple\""];
banana [label = "StringObject \n \"banana\""];
cherry [label = "StringObject \n \"cherry\""];
apple -> cherry -> banana [style = invis];
}
subgraph cluster_array {
style = invis;
array [label = " array | { <array0> array[0] \n redisSortObject | { <obj0> obj | <cmpobj0> u.cmpobj } } | { <array1> array[1] \n redisSortObject | { <obj1> obj | <cmpobj1> u.cmpobj } } | { <array2> array[2] \n redisSortObject | { <obj2> obj | <cmpobj2> u.cmpobj } } "];
}
array:obj0 -> cherry;
array:obj1 -> apple;
array:obj2 -> banana;
apple_id [label = "StringObject \n \"FRUIT-25\""];
banana_id [label = "StringObject \n \"FRUIT-79\""];
cherry_id [label = "StringObject \n \"FRUIT-13\""];
array:cmpobj0 -> cherry_id;
array:cmpobj1 -> apple_id;
array:cmpobj2 -> banana_id;
label = "\n 图 21-14 按 u.cmpobj 所指向的字符串对象进行排序之后的数组";
}](_images/graphviz-ad361521ffb2340ac9672416ac0e40eb3ed34693.png)
![digraph {
rankdir = LR;
subgraph cluster_alphabet {
label = "alphabet 集合\n";
style = dashed;
node [shape = box];
a [label = "StringObject \n \"a\""];
b [label = "StringObject \n \"b\""];
c [label = "StringObject \n \"c\""];
d [label = "StringObject \n \"d\""];
e [label = "StringObject \n \"e\""];
f [label = "StringObject \n \"f\""];
edge [style = invis];
d -> c -> a;
b -> f -> e;
}
array [label = " array | { array[0] \n redisSortObject | { <obj0> obj | u } } | { array[1] \n redisSortObject | { <obj1> obj | u } } | { array[2] \n redisSortObject | { <obj2> obj | u } } | { array[3] \n redisSortObject | { <obj3> obj | u } } | { array[4] \n redisSortObject | { <obj4> obj | u } } | { array[5] \n redisSortObject | { <obj5> obj | u } } ", shape = record];
edge [minlen = 2.0];
array:obj0 -> d;
array:obj1 -> c;
array:obj2 -> a;
array:obj3 -> b;
array:obj4 -> f;
array:obj5 -> e;
label = "\n 图 21-15 将 obj 指针指向集合的各个元素";
}](_images/graphviz-7bbf453dfc91a6d64b7054197fe517ee4adb4968.png)
![digraph {
rankdir = LR;
subgraph cluster_alphabet {
label = "alphabet 集合\n\n";
style = dashed;
node [shape = box];
a [label = "StringObject \n \"a\""];
b [label = "StringObject \n \"b\""];
c [label = "StringObject \n \"c\""];
d [label = "StringObject \n \"d\""];
e [label = "StringObject \n \"e\""];
f [label = "StringObject \n \"f\""];
edge [style = invis];
d -> c -> a;
b -> f -> e;
}
array [label = " array | { array[0] \n redisSortObject | { <obj0> obj | u } } | { array[1] \n redisSortObject | { <obj1> obj | u } } | { array[2] \n redisSortObject | { <obj2> obj | u } } | { array[3] \n redisSortObject | { <obj3> obj | u } } | { array[4] \n redisSortObject | { <obj4> obj | u } } | { array[5] \n redisSortObject | { <obj5> obj | u } } ", shape = record];
edge [minlen = 2.0];
array:obj0 -> a;
array:obj1 -> b;
array:obj2 -> c;
array:obj3 -> d;
array:obj4 -> e;
array:obj5 -> f;
label = "\n 图 21-16 排序后的数组";
}](_images/graphviz-8fe085fe8f59e25f561373a137619c64c48bc34d.png)
![digraph {
rankdir = LR;
subgraph cluster_students {
label = "students 集合";
style = dashed;
node [shape = box];
peter [label = "StringObject \n \"peter\""];
jack [label = "StringObject \n \"jack\""];
tom [label = "StringObject \n \"tom\""];
peter -> jack -> tom [style = invis];
}
node [shape = record];
array [label = " array | { array[0] \n redisSortObject | { <obj0> obj | u } } | { array[1] \n redisSortObject | { <obj1> obj | u } } | { array[2] \n redisSortObject | { <obj2> obj | u } } "];
array:obj0 -> peter;
array:obj1 -> jack;
array:obj2 -> tom;
label = "\n 图 21-17 排序之前的数组";
}](_images/graphviz-18a12b2e02c9ce1249a3186b65e655f4aae74e79.png)
![digraph {
rankdir = LR;
subgraph cluster_students {
label = "students 集合";
style = dashed;
node [shape = box];
peter [label = "StringObject \n \"peter\""];
jack [label = "StringObject \n \"jack\""];
tom [label = "StringObject \n \"tom\""];
peter -> jack -> tom [style = invis];
}
node [shape = record];
array [label = " array | { array[0] \n redisSortObject | { <obj0> obj | u } } | { array[1] \n redisSortObject | { <obj1> obj | u } } | { array[2] \n redisSortObject | { <obj2> obj | u } } "];
array:obj0 -> jack;
array:obj1 -> peter;
array:obj2 -> tom;
label = "\n 图 21-18 排序之后的数组";
}](_images/graphviz-8b1ac497c2c430c3b893fb6f50223e9582e41e47.png)
![digraph {
label = "\n 图 22-1 SDS 表示的位数组";
rankdir = LR;
//
node [shape = record];
redisObject [label = " redisObject | ... | type \n REDIS_STRING | ... | <ptr> ptr "];
sds [label = " <head> sdshdr | free \n 0 | len \n 1 | <buf> buf "];
buf [label = " { buf[0] | buf[1] （空字符） } "];
//
redisObject:ptr -> sds:head;
sds:buf -> buf;
}](_images/graphviz-65afe176bf56a8872089cc288d4d62f9bdc8fed8.png)
![digraph {
label = "\n 图 22-2 一字节长的位数组的 SDS 表示";
rankdir = LR;
//
node [shape = record];
redisObject [label = " redisObject | ... | type \n REDIS_STRING | ... | <ptr> ptr "];
sds [label = " <head> sdshdr | free \n 0 | len \n 1 | <buf> buf "];
buf [label = " { buf[0] | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 0 } | { buf[1] （空字符） } "];
//
redisObject:ptr -> sds:head;
sds:buf -> buf;
}](_images/graphviz-9884e8dc3ab797ba53402067b9dfe9c4a37f49b1.png)
![digraph {
label = "\n 图 22-3 三字节长的位数组的 SDS 表示";
rankdir = LR;
//
node [shape = record];
redisObject [label = " redisObject | ... | type \n REDIS_STRING | ... | <ptr> ptr "];
sds [label = " <head> sdshdr | free \n 0 | len \n 3 | <buf> buf "];
buf [label = " { buf[0] | 1 | 0 | 1 | 0 | 0 | 1 | 0 | 1 } | { buf[1] | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 1 } | { buf[2] | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 } | { buf[3] （空字符） } "];
//
redisObject:ptr -> sds:head;
sds:buf -> buf;
}](_images/graphviz-52abb89ca49de2c84c04416ade157616077e0626.png)
![digraph {
label = "\n 图 22-4 查找并返回 offset 为 3 的二进制位的过程";
//
rankdir = LR;
point_to_buf0 [label = "1) 定位到 buf[0] 字节", shape = plaintext];
point_to_idx3 [label = "2) 返回第 4 个二进制位的值", shape = plaintext];
buf [label = " { <buf0> buf[0] | 1 | 0 | 1 | <idx3> 1 | 0 | 0 | 1 | 0 } | { buf[1] （空字符） } ", shape = record];
//
edge [style = dashed];
point_to_buf0 -> buf:buf0;
point_to_idx3 -> buf:idx3;
}](_images/graphviz-af9c5ceffb3aa070575982dbc1ef00d1f6496706.png)
![digraph {
label = "\n 图 22-5 查找并返回 offset 为 10 的二进制位的过程";
rankdir = LR;
//
node [shape = record];
buf [label = " { buf[0] | 1 | 0 | 1 | 0 | 0 | 1 | 0 | 1 } | { <buf1> buf[1] | 1 | 1 | <bit> 0 | 0 | 0 | 0 | 1 | 1 } | { buf[2] | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 } | { buf[3] | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 } "];
node [shape = plaintext];
point_to_buf [label = "1） 定位到 buf[1] 字节"];
point_to_bit [label = "2） 返回第 3 个二进制位的值"];
//
edge [style = dashed];
point_to_buf -> buf:buf1;
point_to_bit -> buf:bit;
}](_images/graphviz-3a11dc81cb45b0791f28c01c2fd5c805a0c0d60c.png)
![digraph {
label = "\n 图 22-6 SETBIT 命令的执行过程";
//
node [shape = plaintext];
point_to_byte [label = "1） 定位到 buf[0] 字节"];
point_to_bit [label = "2）定位到 buf[0] 字节的第 2 个二进制位 \n 将位现在的值 0 保存到 oldvalue 变量 \n 然后将位的值设置为 1 "];
buf [label = " { { <byte> buf[0] | 1 | <bit> 0 | 1 | 1 | 0 | 0 | 1 | 0 } | { buf[1] （空字符） } } ", shape = record];
//
edge [style = dashed];
point_to_byte -> buf:byte;
point_to_bit -> buf:bit;
}](_images/graphviz-1aac5ce203184eb82535c67eb11255a59e5022a6.png)
![digraph {
label = "\n 图 22-8 扩展空间之后的位数组";
rankdir = LR;
//
node [shape = record];
redisObject [label = " redisObject | ... | type \n REDIS_STRING | ... | <ptr> ptr "];
sds [label = " <head> sdshdr | free \n 2 | len \n 2 | <buf> buf "];
buf [label = " { buf[0] | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 0 } | { buf[1] | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 } | { buf[2] （空字符） } | { buf[3] （未使用） } | { buf[4] （未使用） } "];
//
redisObject:ptr -> sds:head;
sds:buf -> buf;
}](_images/graphviz-f7f8465c6205b8c67bec7f091e0fe773f1223f80.png)
![digraph {
label = "\n 图 22-9 SETBIT 命令的执行过程";
//
node [shape = plaintext];
point_to_byte [label = "1）定位到 buf[1] 字节"];
point_yo_bit [label = "2）定位到 buf[1] 字节的第 5 个二进制位 \n 首先将位现在的值 0 保存到 oldvalue 变量 \n 然后将位的值设置为 1 "];
node [shape = record];
buf [label = " { { buf[0] | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 0 } | { <byte> buf[1] | 0 | 0 | 0 | 0 | <bit> 0 | 0 | 0 | 0 } | { buf[2] （空字符） } | { buf[3] （未使用） } | { buf[4] （未使用） } } "];
//
edge [style = dashed];
point_to_byte -> buf:byte;
point_yo_bit -> buf:bit;
}](_images/graphviz-e8d9b42919a10d2205cb57fca78dc87eaf816e8d.png)
![digraph {
label = "\n 图 22-10 执行 SETBIT 命令之后的位数组";
//
node [shape = record];
buf [label = " { { buf[0] | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 0 } | { <byte> buf[1] | 0 | 0 | 0 | 0 | <bit> 1 | 0 | 0 | 0 } | { buf[2] （空字符） } | { buf[3] （未使用） } | { buf[4] （未使用） } } "];
}](_images/graphviz-37414e9c430061f7cbfc9a629018ebc4b7203e22.png)
![digraph {
label = "\n 图 23-1 slowlogEntry 结构示例";
rankdir = LR;
node [shape = record];
slowlogEntry [label = " slowlogEntry | id \n 3 | time \n 1378781439 | duration \n 10 | <argv> argv | argc \n 3 "];
argv [label = " { { argv[0] | StringObject \n \"SET\" } | { argv[1] | StringObject \n \"number\" } | { argv[2] | StringObject \n \"10086\" } } "];
slowlogEntry:argv -> argv;
}](_images/graphviz-496accb4258b0feb9fbc0503bb9ba49f16e4b6d9.png)
![digraph {
label = "\n 图 23-2 redisServer 结构示例";
rankdir = LR;
node [shape = record];
redisServer [label = " redisServer | ... | slowlog_entry_id \n 6 | <slowlog> slowlog | slowlog_log_slower_than \n 0 | slowlog_max_len \n 5 | ... "];
slowlogEntry_5 [label = " slowlogEntry | id \n 5 | time \n 1378781521 | duration \n 61 | <argv> argv | argc \n 2 "];
slowlogEntry_1 [label = " slowlogEntry | id \n 1 | time \n 1378781425 | duration \n 11 | <argv> argv | argc \n 4 "];
more [label = "...", shape = plaintext]
redisServer:slowlog -> slowlogEntry_5 -> more -> slowlogEntry_1;
}](_images/graphviz-2634cbda11c253dc440086b228cff1c0fbe8efb3.png)
![digraph {
label = "\n 图 24-1 命令的接收和信息的发送";
rankdir = LR;
server [label = "服\n务\n器", shape = box, height = 3.0, width = 1.0];
node [shape = circle, width = 1.3];
client [label = "客户端"];
m1 [label = "监视器 1"];
m2 [label = "监视器 2"];
m3 [label = "监视器 3"];
client -> server [label = "发送命令请求"];
edge [label = "发送命令信息"];
server -> m1;
server -> m2;
server -> m3;
}](_images/graphviz-0a684588293c799f804995f27a2dd6f9da407f8e.png)
![digraph {
label = "\n 图 24-3 客户端 c10086 执行 MONITOR 命令之后的 monitors 链表";
rankdir = LR;
node [shape = record];
server [label = " redisServer | ... | <monitors> monitors | ... "];
c128 [label = "c128"];
c256 [label = "c256"];
c512 [label = "c512"];
c10086 [label = "c10086"];
server:monitors -> c128 -> c256 -> c512 -> c10086;
}](_images/graphviz-01c46b55b5adefb2527bf027a73b5e3c725e2255.png)
![digraph {
label = "\n 图 24-4 服务器将信息发送给各个监视器";
rankdir = LR;
server [label = "服\n务\n器", shape = box, height = 4.0, width = 1.0];
node [shape = circle, width = 1.3];
c128;
c256;
c512;
c10086;
edge [label = "1378822257.329412\n[0 127.0.0.1:56604]\n\"KEYS\" \"*\""];
server -> c128;
server -> c256;
server -> c512;
server -> c10086;
}](_images/graphviz-9f7dd9796b33d69dd221559a21be656d30fec0d7.png)