消息队列 Beanstalkd 源码解析（一）

初稿，还在继续学习源码中…

代码目录结构

.├── Contributing├── LICENSE├── Makefile├── README├── adm ( 做成系统服务相关配置 )├── ct （测试用例代码）├── doc （文档）├── pkg （文档）

重要代码

• tube
• heap
• job
  用两个数据结构描述job。（1）jobrec，job的描述信息，元数据；（2）job，job内容的实际存储

struct job {    Jobrec r; // persistent fields; these get written to the wal //描述job的属性，持久化时这些数据会写到文件中。    /* bookeeping fields; these are in-memory only */    char pad[6];    tube tube;   // 指针，指向一个tube    job prev, next; /* linked list of jobs */    job ht_next; /* Next job in a hash table list */    size_t heap_index; /* where is this job in its current heap */    File *file;    job  fnext;    job  fprev;    void *reserver;    int walresv;    int walused;    char body[]; // written separately to the wal};

• ms
  自定义的集合类型，在此项目中用来管理连接、tube。
• all_jobs_init
  哈希表，存储job,按照job id取模来进行哈希。该哈希表用于快速查找job。

job状态迁移

   put with delay               release with delay  ----------------> [DELAYED] <------------.                        |                   |                        | (time passes)     |                        |                   |   put                  v     reserve       |       delete  -----------------> [READY] ---------> [RESERVED] --------> *poof*                       ^  ^                |  |                       |   \  release      |  |                       |    `-------------'   |                       |                      |                       | kick                 |                       |                      |                       |       bury           |                    [BURIED] <---------------'                       |                       |  delete                        `--------> *poof*

参考文档

• http://blog.csdn.net/sunnycoco05/article/details/52104617
• http://kr.github.io/beanstalkd/
• http://in355hz.iteye.com/blog/1395727
• http://www.bytedancer.net/archives/21
• http://www.fzb.me/2015-3-21-beanstalkd-protocol-chinese-version.html