Function ACLGetCommandID

src/acl.cpp:1137–1163

For ACL purposes, every user has a bitmap with the commands that such * user is allowed to execute. In order to populate the bitmap, every command * should have an assigned ID (that is used to index the bitmap). This function * creates such an ID: it uses sequential IDs, reusing the same ID for the same * command name, so that a command retains the same ID in case of modules that * are unload

 * command name, so that a command retains the same ID in case of modules that
 * are unloaded and later reloaded. */
unsigned long ACLGetCommandID(const char *cmdname) {

    sds lowername = sdsnew(cmdname);
    sdstolower(lowername);
    if (commandId == NULL) commandId = raxNew();
    void *id = raxFind(commandId,(unsigned char*)lowername,sdslen(lowername));
    if (id != raxNotFound) {
        sdsfree(lowername);
        return (unsigned long)id;
    }
    raxInsert(commandId,(unsigned char*)lowername,strlen(lowername),
              (void*)nextid,NULL);
    sdsfree(lowername);
    unsigned long thisid = nextid;
    nextid++;

    /* We never assign the last bit in the user commands bitmap structure,
     * this way we can later check if this bit is set, understanding if the
     * current ACL for the user was created starting with a +@all to add all
     * the possible commands and just subtracting other single commands or
     * categories, or if, instead, the ACL was created just adding commands
     * and command categories from scratch, not allowing future commands by
     * default (loaded via modules). This is useful when rewriting the ACLs
     * with ACL SAVE. */
    if (nextid == USER_COMMAND_BITS_COUNT-1) nextid++;
    return thisid;
}

/* Clear command id table and reset nextid to 0. */
void ACLClearCommandID(void) {