【redis源码学习】redis启动并读取配置文件的过程

redis-server [configfile] [options]

redis-server ./redis.conf --port 6380 --protected-mode no

//结构体稍微有点庞大（接近2W字），所以我稍微缩写一点哈，具体后面有用到再拿出来
struct redisServer {
    /* General */
    pid_t pid;                  /* Main process pid. */
    char *configfile;           /* Absolute config file path, or NULL */
    char *executable;           /* Absolute executable file path. */
    char **exec_argv;           /* Executable argv vector (copy). */
  
  ···
}

int main(int argc, char **argv) {
    struct timeval tv;
    int j;

#ifdef REDIS_TEST
    //这里略去
#endif

    /* We need to initialize our libraries, and the server configuration. */
#ifdef INIT_SETPROCTITLE_REPLACEMENT
    spt_init(argc, argv);		//修改进程名
#endif
    //此处略去一批
    server.sentinel_mode = checkForSentinelMode(argc,argv);	// 检查服务器是否以 Sentinel 模式启动
    initServerConfig();	//将配置文件初始化为默认值（详见后文）
   
	//此处再省一批
	
    /* We need to init sentinel right now as parsing the configuration file
     * in sentinel mode will have the effect of populating the sentinel
     * data structures with master nodes to monitor. */
    if (server.sentinel_mode) {	//今天不讲哨兵，所以不管它
        initSentinelConfig();
        initSentinel();
    }

    //略

	//开始了
    if (argc >= 2) {
        j = 1; /* First option to parse in argv[] */
        sds options = sdsempty();
        char *configfile = NULL;

        /* Handle special options --help and --version */
        if (strcmp(argv[1], "-v") == 0 ||
            strcmp(argv[1], "--version") == 0) version();
        if (strcmp(argv[1], "--help") == 0 ||
            strcmp(argv[1], "-h") == 0) usage();
        if (strcmp(argv[1], "--test-memory") == 0) {
            if (argc == 3) {
                memtest(atoi(argv[2]),50);
                exit(0);
            } else {
                fprintf(stderr,"Please specify the amount of memory to test in megabytes.\n");
                fprintf(stderr,"Example: ./redis-server --test-memory 4096\n\n");
                exit(1);
            }
        }

        /* First argument is the config file name? */
        if (argv[j][0] != '-' || argv[j][1] != '-') {	//如果不是 --开头，那就是配置文件
            configfile = argv[j];
            server.configfile = getAbsolutePath(configfile);
            /* Replace the config file in server.exec_argv with
             * its absolute path. */
            zfree(server.exec_argv[j]);
            server.exec_argv[j] = zstrdup(server.configfile);
            j++;
        }

        /* All the other options are parsed and conceptually appended to the
         * configuration file. For instance --port 6380 will generate the
         * string "port 6380\n" to be parsed after the actual file name
         * is parsed, if any. */
        while(j != argc) {	//读取启动配置项，并存储到一个字符串中
            if (argv[j][0] == '-' && argv[j][1] == '-') {
                /* Option name */
                if (!strcmp(argv[j], "--check-rdb")) {
                    /* Argument has no options, need to skip for parsing. */
                    j++;
                    continue;
                }
                if (sdslen(options)) options = sdscat(options,"\n");
                options = sdscat(options,argv[j]+2);
                options = sdscat(options," ");
            } else {
                /* Option argument */
                options = sdscatrepr(options,argv[j],strlen(argv[j]));
                options = sdscat(options," ");
            }
            j++;
        }
        
        //略
        
        resetServerSaveParams();
        loadServerConfig(configfile,options);	//从配置文件中加载所有配置项，见下文
        sdsfree(options);
    }

  	//略

    initServer();
   	
   	//略

    redisSetCpuAffinity(server.server_cpulist);
    aeMain(server.el);
    aeDeleteEventLoop(server.el);
    return 0;
}

void initServerConfig(void) {
    int j;

    updateCachedTime(1);
    getRandomHexChars(server.runid,CONFIG_RUN_ID_SIZE);
    server.runid[CONFIG_RUN_ID_SIZE] = '\0';
    changeReplicationId();
    clearReplicationId2();
    server.hz = CONFIG_DEFAULT_HZ; /* Initialize it ASAP, even if it may get
                                      updated later after loading the config.
                                      This value may be used before the server
                                      is initialized. */
    server.timezone = getTimeZone(); /* Initialized by tzset(). */
    server.configfile = NULL;
	
	//略
	
    /* Replication related */
    server.masterauth = NULL;
    server.masterhost = NULL;
    server.masterport = 6379;
    server.master = NULL;
  
    //略

    /* By default we want scripts to be always replicated by effects
     * (single commands executed by the script), and not by sending the
     * script to the slave / AOF. This is the new way starting from
     * Redis 5. However it is possible to revert it via redis.conf. */
    server.lua_always_replicate_commands = 1;

    initConfigValues();
}

void loadServerConfigFromString(char *config) {
    char *err = NULL;
    int linenum = 0, totlines, i;
    int slaveof_linenum = 0;
    sds *lines;

    lines = sdssplitlen(config,strlen(config),"\n",1,&totlines);

    for (i = 0; i < totlines; i++) {
        sds *argv;
        int argc;

        linenum = i+1;
        lines[i] = sdstrim(lines[i]," \t\r\n");

        /* Skip comments and blank lines */
        if (lines[i][0] == '#' || lines[i][0] == '\0') continue;

        /* Split into arguments */
        argv = sdssplitargs(lines[i],&argc);
        if (argv == NULL) {
            err = "Unbalanced quotes in configuration line";
            goto loaderr;
        }

        /* Skip this line if the resulting command vector is empty. */
        if (argc == 0) {
            sdsfreesplitres(argv,argc);
            continue;
        }
        sdstolower(argv[0]);

        /* Iterate the configs that are standard */
        int match = 0;
        for (standardConfig *config = configs; config->name != NULL; config++) {
            if ((!strcasecmp(argv[0],config->name) ||
                (config->alias && !strcasecmp(argv[0],config->alias))))
            {
                if (argc != 2) {
                    err = "wrong number of arguments";
                    goto loaderr;
                }
                if (!config->interface.set(config->data, argv[1], 0, &err)) {
                    goto loaderr;
                }

                match = 1;
                break;
            }
        }

        if (match) {
            sdsfreesplitres(argv,argc);
            continue;
        }

        /* Execute config directives */
        if (!strcasecmp(argv[0],"bind") && argc >= 2) {
            int j, addresses = argc-1;

            if (addresses > CONFIG_BINDADDR_MAX) {
                err = "Too many bind addresses specified"; goto loaderr;
            }
            /* Free old bind addresses */
            for (j = 0; j < server.bindaddr_count; j++) {
                zfree(server.bindaddr[j]);
            }
            for (j = 0; j < addresses; j++)
                server.bindaddr[j] = zstrdup(argv[j+1]);
            server.bindaddr_count = addresses;
        } else if (!strcasecmp(argv[0],"unixsocketperm") && argc == 2) {
            errno = 0;
            server.unixsocketperm = (mode_t)strtol(argv[1], NULL, 8);
            if (errno || server.unixsocketperm > 0777) {
                err = "Invalid socket file permissions"; goto loaderr;
            }
        } else if (!strcasecmp(argv[0],"save")) {
            if (argc == 3) {
                int seconds = atoi(argv[1]);
                int changes = atoi(argv[2]);
                if (seconds < 1 || changes < 0) {
                    err = "Invalid save parameters"; goto loaderr;
                }
                appendServerSaveParams(seconds,changes);
            } else if (argc == 2 && !strcasecmp(argv[1],"")) {
                resetServerSaveParams();
            }
        } else if (!strcasecmp(argv[0],"dir") && argc == 2) {
            if (chdir(argv[1]) == -1) {
                serverLog(LL_WARNING,"Can't chdir to '%s': %s",
                    argv[1], strerror(errno));
                exit(1);
            }
        } else if (!strcasecmp(argv[0],"logfile") && argc == 2) {
            FILE *logfp;

            zfree(server.logfile);
            server.logfile = zstrdup(argv[1]);
            if (server.logfile[0] != '\0') {
                /* Test if we are able to open the file. The server will not
                 * be able to abort just for this problem later... */
                logfp = fopen(server.logfile,"a");
                if (logfp == NULL) {
                    err = sdscatprintf(sdsempty(),
                        "Can't open the log file: %s", strerror(errno));
                    goto loaderr;
                }
                fclose(logfp);
            }
        } else if (!strcasecmp(argv[0],"include") && argc == 2) {
            loadServerConfig(argv[1],NULL);
        } else if ((!strcasecmp(argv[0],"client-query-buffer-limit")) && argc == 2) {
             server.client_max_querybuf_len = memtoll(argv[1],NULL);
        } else if ((!strcasecmp(argv[0],"slaveof") ||
                    !strcasecmp(argv[0],"replicaof")) && argc == 3) {
            slaveof_linenum = linenum;
            server.masterhost = sdsnew(argv[1]);
            server.masterport = atoi(argv[2]);
            server.repl_state = REPL_STATE_CONNECT;
        } else if (!strcasecmp(argv[0],"requirepass") && argc == 2) {
            if (strlen(argv[1]) > CONFIG_AUTHPASS_MAX_LEN) {
                err = "Password is longer than CONFIG_AUTHPASS_MAX_LEN";
                goto loaderr;
            }
            /* The old "requirepass" directive just translates to setting
             * a password to the default user. The only thing we do
             * additionally is to remember the cleartext password in this
             * case, for backward compatibility with Redis <= 5. */
            ACLSetUser(DefaultUser,"resetpass",-1);
            sds aclop = sdscatprintf(sdsempty(),">%s",argv[1]);
            ACLSetUser(DefaultUser,aclop,sdslen(aclop));
            sdsfree(aclop);
            sdsfree(server.requirepass);
            server.requirepass = sdsnew(argv[1]);
        } else if (!strcasecmp(argv[0],"list-max-ziplist-entries") && argc == 2){
            /* DEAD OPTION */
        } else if (!strcasecmp(argv[0],"list-max-ziplist-value") && argc == 2) {
            /* DEAD OPTION */
        } else if (!strcasecmp(argv[0],"rename-command") && argc == 3) {
            struct redisCommand *cmd = lookupCommand(argv[1]);
            int retval;

            if (!cmd) {
                err = "No such command in rename-command";
                goto loaderr;
            }

            /* If the target command name is the empty string we just
             * remove it from the command table. */
            retval = dictDelete(server.commands, argv[1]);
            serverAssert(retval == DICT_OK);

            /* Otherwise we re-add the command under a different name. */
            if (sdslen(argv[2]) != 0) {
                sds copy = sdsdup(argv[2]);

                retval = dictAdd(server.commands, copy, cmd);
                if (retval != DICT_OK) {
                    sdsfree(copy);
                    err = "Target command name already exists"; goto loaderr;
                }
            }
        } else if (!strcasecmp(argv[0],"cluster-config-file") && argc == 2) {
            zfree(server.cluster_configfile);
            server.cluster_configfile = zstrdup(argv[1]);
        } else if (!strcasecmp(argv[0],"client-output-buffer-limit") &&
                   argc == 5)
        {
            int class = getClientTypeByName(argv[1]);
            unsigned long long hard, soft;
            int soft_seconds;

            if (class == -1 || class == CLIENT_TYPE_MASTER) {
                err = "Unrecognized client limit class: the user specified "
                "an invalid one, or 'master' which has no buffer limits.";
                goto loaderr;
            }
            hard = memtoll(argv[2],NULL);
            soft = memtoll(argv[3],NULL);
            soft_seconds = atoi(argv[4]);
            if (soft_seconds < 0) {
                err = "Negative number of seconds in soft limit is invalid";
                goto loaderr;
            }
            server.client_obuf_limits[class].hard_limit_bytes = hard;
            server.client_obuf_limits[class].soft_limit_bytes = soft;
            server.client_obuf_limits[class].soft_limit_seconds = soft_seconds;
        } else if (!strcasecmp(argv[0],"notify-keyspace-events") && argc == 2) {
            int flags = keyspaceEventsStringToFlags(argv[1]);

            if (flags == -1) {
                err = "Invalid event class character. Use 'g$lshzxeA'.";
                goto loaderr;
            }
            server.notify_keyspace_events = flags;
        } else if (!strcasecmp(argv[0],"user") && argc >= 2) {
            int argc_err;
            if (ACLAppendUserForLoading(argv,argc,&argc_err) == C_ERR) {
                char buf[1024];
                char *errmsg = ACLSetUserStringError();
                snprintf(buf,sizeof(buf),"Error in user declaration '%s': %s",
                    argv[argc_err],errmsg);
                err = buf;
                goto loaderr;
            }
        } else if (!strcasecmp(argv[0],"loadmodule") && argc >= 2) {
            queueLoadModule(argv[1],&argv[2],argc-2);
        } else if (!strcasecmp(argv[0],"sentinel")) {
            /* argc == 1 is handled by main() as we need to enter the sentinel
             * mode ASAP. */
            if (argc != 1) {
                if (!server.sentinel_mode) {
                    err = "sentinel directive while not in sentinel mode";
                    goto loaderr;
                }
                err = sentinelHandleConfiguration(argv+1,argc-1);
                if (err) goto loaderr;
            }
        } else {
            err = "Bad directive or wrong number of arguments"; goto loaderr;
        }
        sdsfreesplitres(argv,argc);
    }

    /* Sanity checks. */
    if (server.cluster_enabled && server.masterhost) {
        linenum = slaveof_linenum;
        i = linenum-1;
        err = "replicaof directive not allowed in cluster mode";
        goto loaderr;
    }

    sdsfreesplitres(lines,totlines);
    return;

loaderr:
    fprintf(stderr, "\n*** FATAL CONFIG FILE ERROR (Redis %s) ***\n",
        REDIS_VERSION);
    fprintf(stderr, "Reading the configuration file, at line %d\n", linenum);
    fprintf(stderr, ">>> '%s'\n", lines[i]);
    fprintf(stderr, "%s\n", err);
    exit(1);
}