深入刨析Redis存储技术设计艺术（二）
三、Redis主存储
3.1、存储相关结构体
redisServer：服务器
server.h
struct redisServer { /* General */ pid_t pid; /* Main process pid. */ pthread_t main_thread_id; /* Main thread id */ char *configfile; /* Absolute config file path, or NULL */ char *executable; /* Absolute executable file path. */ char **exec_argv; /* Executable argv vector (copy). */ int dynamic_hz; /* Change hz value depending on # of clients. */ int config_hz; /* Configured HZ value. May be different than the actual 'hz' field value if dynamic-hz is enabled. */ mode_t umask; /* The umask value of the process on startup */ int hz; /* serverCron() calls frequency in hertz */ int in_fork_child; /* indication that this is a fork child */ redisDb *db; dict *commands; /* Command table */ dict *orig_commands; /* Command table before command renaming. */ aeEventLoop *el; rax *errors; /* Errors table */ redisAtomic unsigned int lruclock; /* Clock for LRU eviction */ volatile sig_atomic_t shutdown_asap; /* SHUTDOWN needed ASAP */ int activerehashing; /* Incremental rehash in serverCron() */ int active_defrag_running; /* Active defragmentation running (holds current scan aggressiveness) */ char *pidfile; /* PID file path */ int arch_bits; /* 32 or 64 depending on sizeof(long) */ int cronloops; /* Number of times the cron function run */ char runid[CONFIG_RUN_ID_SIZE+1]; /* ID always different at every exec. */ int sentinel_mode; /* True if this instance is a Sentinel. */ size_t initial_memory_usage; /* Bytes used after initialization. */ int always_show_logo; /* Show logo even for non-stdout logging. */ int in_eval; /* Are we inside EVAL? */ int in_exec; /* Are we inside EXEC? */ int propagate_in_transaction; /* Make sure we don't propagate nested MULTI/EXEC */ char *ignore_warnings; /* Config: warnings that should be ignored. */ int client_pause_in_transaction; /* Was a client pause executed during this Exec? */ /* Modules */ dict *moduleapi; /* Exported core APIs dictionary for modules. */ dict *sharedapi; /* Like moduleapi but containing the APIs that modules share with each other. */ list *loadmodule_queue; /* List of modules to load at startup. */ int module_blocked_pipe[2]; /* Pipe used to awake the event loop if a client blocked on a module command needs to be processed. */ pid_t child_pid; /* PID of current child */ int child_type; /* Type of current child */ client *module_client; /* "Fake" client to call Redis from modules */ /* Networking */ int port; /* TCP listening port */ int tls_port; /* TLS listening port */ int tcp_backlog; /* TCP listen() backlog */ char *bindaddr[CONFIG_BINDADDR_MAX]; /* Addresses we should bind to */ int bindaddr_count; /* Number of addresses in server.bindaddr[] */ char *unixsocket; /* UNIX socket path */ mode_t unixsocketperm; /* UNIX socket permission */ socketFds ipfd; /* TCP socket file descriptors */ socketFds tlsfd; /* TLS socket file descriptors */ int sofd; /* Unix socket file descriptor */ socketFds cfd; /* Cluster bus listening socket */ list *clients; /* List of active clients */ list *clients_to_close; /* Clients to close asynchronously */ list *clients_pending_write; /* There is to write or install handler. */ list *clients_pending_read; /* Client has pending read socket buffers. */ list *slaves, *monitors; /* List of slaves and MONITORs */ client *current_client; /* Current client executing the command. */ rax *clients_timeout_table; /* Radix tree for blocked clients timeouts. */ long fixed_time_expire; /* If > 0, expire keys against server.mstime. */ rax *clients_index; /* Active clients dictionary by client ID. */ pause_type client_pause_type; /* True if clients are currently paused */ list *paused_clients; /* List of pause clients */ mstime_t client_pause_end_time; /* Time when we undo clients_paused */ char neterr[ANET_ERR_LEN]; /* Error buffer for anet.c */ dict *migrate_cached_sockets;/* MIGRATE cached sockets */ redisAtomic uint64_t next_client_id; /* Next client unique ID. Incremental. */ int protected_mode; /* Don't accept external connections. */ int gopher_enabled; /* If true the server will reply to gopher queries. Will still serve RESP2 queries. */ int io_threads_num; /* Number of IO threads to use. */ int io_threads_do_reads; /* Read and parse from IO threads? */ int io_threads_active; /* Is IO threads currently active? */ long long events_processed_while_blocked; /* processEventsWhileBlocked() */
/* RDB / AOF loading information */ volatile sig_atomic_t loading; /* We are loading data from disk if true */ off_t loading_total_bytes; off_t loading_rdb_used_mem; off_t loading_loaded_bytes; time_t loading_start_time; off_t loading_process_events_interval_bytes; /* Fast pointers to often looked up command */ struct redisCommand *delCommand, *multiCommand, *lpushCommand, *lpopCommand, *rpopCommand, *zpopminCommand, *zpopmaxCommand, *sremCommand, *execCommand, *expireCommand, *pexpireCommand, *xclaimCommand, *xgroupCommand, *rpoplpushCommand, *lmoveCommand; /* Fields used only for stats */ time_t stat_starttime; /* Server start time */ long long stat_numcommands; /* Number of processed commands */ long long stat_numconnections; /* Number of connections received */ long long stat_expiredkeys; /* Number of expired keys */ double stat_expired_stale_perc; /* Percentage of keys probably expired */ long long stat_expired_time_cap_reached_count; /* Early expire cylce stops.*/ long long stat_expire_cycle_time_used; /* Cumulative microseconds used. */ long long stat_evictedkeys; /* Number of evicted keys (maxmemory) */ long long stat_keyspace_hits; /* Number of successful lookups of keys */ long long stat_keyspace_misses; /* Number of failed lookups of keys */ long long stat_active_defrag_hits; /* number of allocations moved */ long long stat_active_defrag_misses; /* number of allocations scanned but not moved */ long long stat_active_defrag_key_hits; /* number of keys with moved allocations */ long long stat_active_defrag_key_misses;/* number of keys scanned and not moved */ long long stat_active_defrag_scanned; /* number of dictEntries scanned */ size_t stat_peak_memory; /* Max used memory record */ long long stat_fork_time; /* Time needed to perform latest fork() */ double stat_fork_rate; /* Fork rate in GB/sec. */ long long stat_total_forks; /* Total count of fork. */ long long stat_rejected_conn; /* Clients rejected because of maxclients */ long long stat_sync_full; /* Number of full resyncs with slaves. */ long long stat_sync_partial_ok; /* Number of accepted PSYNC requests. */ long long stat_sync_partial_err;/* Number of unaccepted PSYNC requests. */ list *slowlog; /* SLOWLOG list of commands */ long long slowlog_entry_id; /* SLOWLOG current entry ID */ long long slowlog_log_slower_than; /* SLOWLOG time limit (to get logged) */ unsigned long slowlog_max_len; /* SLOWLOG max number of items logged */ struct malloc_stats cron_malloc_stats; /* sampled in serverCron(). */ redisAtomic long long stat_net_input_bytes; /* Bytes read from network. */ redisAtomic long long stat_net_output_bytes; /* Bytes written to network. */ size_t stat_current_cow_bytes; /* Copy on write bytes while child is active. */ monotime stat_current_cow_updated; /* Last update time of stat_current_cow_bytes */ size_t stat_current_save_keys_processed; /* Processed keys while child is active. */ size_t stat_current_save_keys_total; /* Number of keys when child started. */ size_t stat_rdb_cow_bytes; /* Copy on write bytes during RDB saving. */