文章目录
- 配置文件
- redisServer
- main函数
- initServerConfig
- loadServerConfigFromString
配置文件
一个好的项目，是无状态的。 状态在哪里？在配置文件里。
这不我的毕设马上要用到开机配置文件了嘛，但是没有什么太好的想法，于是就想着学学redis是如何实现这个过程的，学完马上就能学以致用了。
redis服务器的启动命令如下：
代码语言：javascript复制redis-server [configfile] [options]configfile 参数指定配置文件，options 参数指定启动配置项，可以覆盖配置文件中的配置项。
举个栗子：
代码语言：javascript复制redis-server ./redis.conf --port 6380 --protected-mode noredisServer
关于配置信息，存储在如下结构体中：
代码语言：javascript复制//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). */
···
}main函数
这是一个极长的函数，不过没有那个结构体长，而我们此次要学的技法也主要是在这里面，所以还是能接受的。
代码语言：javascript复制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 4096nn");
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 6380n" 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;
}initServerConfig
学习一下，毕竟不是每次启动都非得带上配置文件不是？
代码语言：javascript复制void initServerConfig(void) {
int j;
updateCachedTime(1);
getRandomHexChars(server.runid,CONFIG_RUN_ID_SIZE);
server.runid[CONFIG_RUN_ID_SIZE] = ' ';
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();
}loadServerConfigFromString
代码语言：javascript复制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]," trn");
/* Skip comments and blank lines */
if (lines[i][0] == '#' || lines[i][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] != ' ') {
/* 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 %dn", linenum);
fprintf(stderr, ">>> '%s'n", lines[i]);
fprintf(stderr, "%sn", err);
exit(1);
}
