Redis 命令映射表初始化
redis 命令映射表存儲,使用hashTable
struct redisServer {
dict *commands; /* Command table */
}
redis command結構體
最重要的是處理函數,以及name屬性
typedef void redisCommandProc(client *c);
typedef int *redisGetKeysProc(struct redisCommand *cmd, robj **argv, int argc, int *numkeys);
struct redisCommand {
char *name;
redisCommandProc *proc;
int arity;
char *sflags; /* Flags as string representation, one char per flag. */
int flags; /* The actual flags, obtained from the 'sflags' field. */
/* Use a function to determine keys arguments in a command line.
* Used for Redis Cluster redirect. */
redisGetKeysProc *getkeys_proc;
/* What keys should be loaded in background when calling this command? */
int firstkey; /* The first argument that's a key (0 = no keys) */
int lastkey; /* The last argument that's a key */
int keystep; /* The step between first and last key */
long long microseconds, calls;
};
redisCommandTable 聲明
struct redisCommand redisCommandTable[] = {
{"module",moduleCommand,-2,"as",0,NULL,0,0,0,0,0},
{"get",getCommand,2,"rF",0,NULL,1,1,1,0,0},
{"set",setCommand,-3,"wm",0,NULL,1,1,1,0,0},
...
{"lolwut",lolwutCommand,-1,"r",0,NULL,0,0,0,0,0}
};
將name當作key,redisCommand結構體存儲到hash表中
/* Populates the Redis Command Table starting from the hard coded list
* we have on top of redis.c file. */
void populateCommandTable(void) {
int j;
int numcommands = sizeof(redisCommandTable)/sizeof(struct redisCommand);
for (j = 0; j < numcommands; j++) {
struct redisCommand *c = redisCommandTable+j;
char *f = c->sflags;
int retval1, retval2;
while(*f != '\0') {
switch(*f) {
case 'w': c->flags |= CMD_WRITE; break;
case 'r': c->flags |= CMD_READONLY; break;
case 'm': c->flags |= CMD_DENYOOM; break;
case 'a': c->flags |= CMD_ADMIN; break;
case 'p': c->flags |= CMD_PUBSUB; break;
case 's': c->flags |= CMD_NOSCRIPT; break;
case 'R': c->flags |= CMD_RANDOM; break;
case 'S': c->flags |= CMD_SORT_FOR_SCRIPT; break;
case 'l': c->flags |= CMD_LOADING; break;
case 't': c->flags |= CMD_STALE; break;
case 'M': c->flags |= CMD_SKIP_MONITOR; break;
case 'k': c->flags |= CMD_ASKING; break;
case 'F': c->flags |= CMD_FAST; break;
default: serverPanic("Unsupported command flag"); break;
}
f++;
}
retval1 = dictAdd(server.commands, sdsnew(c->name), c);
/* Populate an additional dictionary that will be unaffected
* by rename-command statements in redis.conf. */
retval2 = dictAdd(server.orig_commands, sdsnew(c->name), c);
serverAssert(retval1 == DICT_OK && retval2 == DICT_OK);
}
}