Redis(5.0.0)持久化AOF和 RDB 结合源码分析

主要是挖个坑。候补（代码还没看完。。）

https://github.com/antirez/redis/tree/5.0

一、Redis保存持久化文件

二、Redis启动加载持久化文件

src/server.c loadDataFromDisk函数 AOF 和 RDB 通过不同的方式加载

 1 /* Function called at startup to load RDB or AOF file in memory. */
 2 void loadDataFromDisk(void) {
 3     long long start = ustime();
 4     if (server.aof_state == AOF_ON) {
 5         if (loadAppendOnlyFile(server.aof_filename) == C_OK)
 6             serverLog(LL_NOTICE,"DB loaded from append only file: %.3f seconds",(float)(ustime()-start)/1000000);
 7     } else {
 8         rdbSaveInfo rsi = RDB_SAVE_INFO_INIT;
 9         if (rdbLoad(server.rdb_filename,&rsi) == C_OK) {
10             serverLog(LL_NOTICE,"DB loaded from disk: %.3f seconds",
11                 (float)(ustime()-start)/1000000);
12 
13             /* Restore the replication ID / offset from the RDB file. */
14             if (server.masterhost &&
15                 rsi.repl_id_is_set &&
16                 rsi.repl_offset != -1 &&
17                 /* Note that older implementations may save a repl_stream_db
18                  * of -1 inside the RDB file in a wrong way, see more information
19                  * in function rdbPopulateSaveInfo. */
20                 rsi.repl_stream_db != -1)
21             {
22                 memcpy(server.replid,rsi.repl_id,sizeof(server.replid));
23                 server.master_repl_offset = rsi.repl_offset;
24                 /* If we are a slave, create a cached master from this
25                  * information, in order to allow partial resynchronizations
26                  * with masters. */
27                 replicationCacheMasterUsingMyself();
28                 selectDb(server.cached_master,rsi.repl_stream_db);
29             }
30         } else if (errno != ENOENT) {
31             serverLog(LL_WARNING,"Fatal error loading the DB: %s. Exiting.",strerror(errno));
32             exit(1);
33         }
34     }
35 }

loadDataFromDisk