从main开始我们最先看到的是初始化服务器配置initServerConfig方法,initServerConfig用来初始化默认配置
void initServerConfig()
{
int j;
// 服务器状态
getRandomHexChars(server.runid, REDIS_RUN_ID_SIZE); // 设置服务器的运行本服务器的 RUN ID
server.configfile = NULL; // 配置文件的绝对路径
server.hz = REDIS_DEFAULT_HZ; // 设置默认服务器频率
// 为运行 ID 加上结尾字符
server.runid[REDIS_RUN_ID_SIZE] = '\0';
server.arch_bits = (sizeof(long) == 8) ? 64 : 32; // 设置服务器是32位还是64位
server.port = REDIS_SERVERPORT; // 默认端口号
server.tcp_backlog = REDIS_TCP_BACKLOG; // 创建tcp的参数
server.bindaddr_count = 0; // 绑定地址数量
server.unixsocket = NULL;
server.unixsocketperm = REDIS_DEFAULT_UNIX_SOCKET_PERM;
server.ipfd_count = 0; // 描述符数量
server.sofd = -1; // UNIX 套接字文件描述符
server.dbnum = REDIS_DEFAULT_DBNUM; // 默认创建数据库数
server.verbosity = REDIS_DEFAULT_VERBOSITY;
server.maxidletime = REDIS_MAXIDLETIME; // 客户端超时,默认不超时
server.tcpkeepalive = REDIS_DEFAULT_TCP_KEEPALIVE;
server.active_expire_enabled = 1;
server.client_max_querybuf_len = REDIS_MAX_QUERYBUF_LEN; // 客户端查询大小默认1G
server.saveparams = NULL;
server.loading = 0; // 正在载入本地文件
server.logfile = zstrdup(REDIS_DEFAULT_LOGFILE); // 日志文件地址
server.syslog_enabled = REDIS_DEFAULT_SYSLOG_ENABLED; //syslog
server.syslog_ident = zstrdup(REDIS_DEFAULT_SYSLOG_IDENT);
server.syslog_facility = LOG_LOCAL0;
server.daemonize = REDIS_DEFAULT_DAEMONIZE; // 是不是守护进程
server.aof_state = REDIS_AOF_OFF; // aof持久化相关配置
server.aof_fsync = REDIS_DEFAULT_AOF_FSYNC;
server.aof_no_fsync_on_rewrite = REDIS_DEFAULT_AOF_NO_FSYNC_ON_REWRITE;
server.aof_rewrite_perc = REDIS_AOF_REWRITE_PERC;
server.aof_rewrite_min_size = REDIS_AOF_REWRITE_MIN_SIZE;
server.aof_rewrite_base_size = 0;
server.aof_rewrite_scheduled = 0;
server.aof_last_fsync = time(NULL);
server.aof_rewrite_time_last = -1;
server.aof_rewrite_time_start = -1;
server.aof_lastbgrewrite_status = REDIS_OK;
server.aof_delayed_fsync = 0;
server.aof_fd = -1;
server.aof_selected_db = -1; /* Make sure the first time will not match */
server.aof_flush_postponed_start = 0;
server.aof_rewrite_incremental_fsync = REDIS_DEFAULT_AOF_REWRITE_INCREMENTAL_FSYNC;
server.pidfile = zstrdup(REDIS_DEFAULT_PID_FILE);
server.rdb_filename = zstrdup(REDIS_DEFAULT_RDB_FILENAME); // rdb持久化的文件名
server.aof_filename = zstrdup(REDIS_DEFAULT_AOF_FILENAME); // aof持久化的文件名
server.requirepass = NULL; // 认证
server.rdb_compression = REDIS_DEFAULT_RDB_COMPRESSION; // rdb使用lzf压缩
server.rdb_checksum = REDIS_DEFAULT_RDB_CHECKSUM;
server.stop_writes_on_bgsave_err = REDIS_DEFAULT_STOP_WRITES_ON_BGSAVE_ERROR;
server.activerehashing = REDIS_DEFAULT_ACTIVE_REHASHING; // 渐进式重算哈希
server.notify_keyspace_events = 0;
server.maxclients = REDIS_MAX_CLIENTS; // 最大客户端数,默认10000
server.bpop_blocked_clients = 0;
server.maxmemory = REDIS_DEFAULT_MAXMEMORY; // 最大内存使用
server.maxmemory_policy = REDIS_DEFAULT_MAXMEMORY_POLICY; // 淘汰策略,默认不能写就报错
server.maxmemory_samples = REDIS_DEFAULT_MAXMEMORY_SAMPLES;
server.hash_max_ziplist_entries = REDIS_HASH_MAX_ZIPLIST_ENTRIES; // 表示哈希类型对象中压缩列表节点的最大数量
server.hash_max_ziplist_value = REDIS_HASH_MAX_ZIPLIST_VALUE; //表示哈希类型对象中压缩列表节点的最大长度
server.list_max_ziplist_entries = REDIS_LIST_MAX_ZIPLIST_ENTRIES;
server.list_max_ziplist_value = REDIS_LIST_MAX_ZIPLIST_VALUE;
server.set_max_intset_entries = REDIS_SET_MAX_INTSET_ENTRIES;
server.zset_max_ziplist_entries = REDIS_ZSET_MAX_ZIPLIST_ENTRIES;
server.zset_max_ziplist_value = REDIS_ZSET_MAX_ZIPLIST_VALUE;
server.hll_sparse_max_bytes = REDIS_DEFAULT_HLL_SPARSE_MAX_BYTES; // HyperLogLog统计相关
server.shutdown_asap = 0; //关闭标识
server.repl_ping_slave_period = REDIS_REPL_PING_SLAVE_PERIOD;
server.repl_timeout = REDIS_REPL_TIMEOUT;
server.repl_min_slaves_to_write = REDIS_DEFAULT_MIN_SLAVES_TO_WRITE;
server.repl_min_slaves_max_lag = REDIS_DEFAULT_MIN_SLAVES_MAX_LAG;
server.cluster_enabled = 0; // 分布式集群
server.cluster_node_timeout = REDIS_CLUSTER_DEFAULT_NODE_TIMEOUT;
server.cluster_migration_barrier = REDIS_CLUSTER_DEFAULT_MIGRATION_BARRIER;
server.cluster_configfile = zstrdup(REDIS_DEFAULT_CLUSTER_CONFIG_FILE);
server.lua_caller = NULL;
server.lua_time_limit = REDIS_LUA_TIME_LIMIT; // lua执行限制5秒
server.lua_client = NULL; // 一个执行命令的客户端
server.lua_timedout = 0;
server.migrate_cached_sockets = dictCreate(&migrateCacheDictType, NULL); // 套接字缓存字典
server.loading_process_events_interval_bytes = (1024 * 1024 * 2);
// 初始化 LRU 时间
server.lruclock = getLRUClock();
// 初始化并设置保存条件
resetServerSaveParams();
appendServerSaveParams(60 * 60, 1); /* save after 1 hour and 1 change */
appendServerSaveParams(300, 100); /* save after 5 minutes and 100 changes */
appendServerSaveParams(60, 10000); /* save after 1 minute and 10000 changes */
/* Replication related */
// 初始化和复制相关的状态
server.masterauth = NULL;
server.masterhost = NULL;
server.masterport = 6379;
server.master = NULL;
server.cached_master = NULL;
server.repl_master_initial_offset = -1;
server.repl_state = REDIS_REPL_NONE;
server.repl_syncio_timeout = REDIS_REPL_SYNCIO_TIMEOUT;
server.repl_serve_stale_data = REDIS_DEFAULT_SLAVE_SERVE_STALE_DATA;
server.repl_slave_ro = REDIS_DEFAULT_SLAVE_READ_ONLY;
server.repl_down_since = 0; /* Never connected, repl is down since EVER. */
server.repl_disable_tcp_nodelay = REDIS_DEFAULT_REPL_DISABLE_TCP_NODELAY;
server.slave_priority = REDIS_DEFAULT_SLAVE_PRIORITY;
server.master_repl_offset = 0;
/* Replication partial resync backlog */
// 初始化 PSYNC 命令所使用的 backlog
server.repl_backlog = NULL;
server.repl_backlog_size = REDIS_DEFAULT_REPL_BACKLOG_SIZE;
server.repl_backlog_histlen = 0;
server.repl_backlog_idx = 0;
server.repl_backlog_off = 0;
server.repl_backlog_time_limit = REDIS_DEFAULT_REPL_BACKLOG_TIME_LIMIT;
server.repl_no_slaves_since = time(NULL);
/* Client output buffer limits */
// 设置客户端的输出缓冲区限制
for (j = 0; j < REDIS_CLIENT_LIMIT_NUM_CLASSES; j++)
server.client_obuf_limits[j] = clientBufferLimitsDefaults[j];
/* Double constants initialization */
// 初始化浮点常量
R_Zero = 0.0;
R_PosInf = 1.0 / R_Zero;
R_NegInf = -1.0 / R_Zero;
R_Nan = R_Zero / R_Zero;
/* Command table -- we initiialize it here as it is part of the
* initial configuration, since command names may be changed via
* redis.conf using the rename-command directive. */
// 初始化命令表
// 在这里初始化是因为接下来读取 .conf 文件时可能会用到这些命令
server.commands = dictCreate(&commandTableDictType, NULL);
server.orig_commands = dictCreate(&commandTableDictType, NULL);
populateCommandTable();
server.delCommand = lookupCommandByCString("del");
server.multiCommand = lookupCommandByCString("multi");
server.lpushCommand = lookupCommandByCString("lpush");
server.lpopCommand = lookupCommandByCString("lpop");
server.rpopCommand = lookupCommandByCString("rpop");
/* Slow log */
// 初始化慢查询日志
server.slowlog_log_slower_than = REDIS_SLOWLOG_LOG_SLOWER_THAN;
server.slowlog_max_len = REDIS_SLOWLOG_MAX_LEN;
/* Debugging */
// 初始化调试项
server.assert_failed = "<no assertion failed>";
server.assert_file = "<no file>";
server.assert_line = 0;
server.bug_report_start = 0;
server.watchdog_period = 0;
}基于版本3.0.0版本,点击下载https://download.redis.io/releases/redis-3.0.0.tar.gz
本文地址，https://www.ccagml.com/?p=357