Function objectCommand

app/redis-6.2.6/src/object.c:1255–1306

Object command allows to inspect the internals of a Redis Object. * Usage: OBJECT */

/* Object command allows to inspect the internals of a Redis Object.
 * Usage: OBJECT <refcount|encoding|idletime|freq> <key> */
void objectCommand(client *c) {
    robj *o;

    if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"help")) {
        const char *help[] = {
"ENCODING <key>",
"    Return the kind of internal representation used in order to store the value",
"    associated with a <key>.",
"FREQ <key>",
"    Return the access frequency index of the <key>. The returned integer is",
"    proportional to the logarithm of the recent access frequency of the key.",
"IDLETIME <key>",
"    Return the idle time of the <key>, that is the approximated number of",
"    seconds elapsed since the last access to the key.",
"REFCOUNT <key>",
"    Return the number of references of the value associated with the specified",
"    <key>.",
NULL
        };
        addReplyHelp(c, help);
    } else if (!strcasecmp(c->argv[1]->ptr,"refcount") && c->argc == 3) {
        if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.null[c->resp]))
                == NULL) return;
        addReplyLongLong(c,o->refcount);
    } else if (!strcasecmp(c->argv[1]->ptr,"encoding") && c->argc == 3) {
        if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.null[c->resp]))
                == NULL) return;
        addReplyBulkCString(c,strEncoding(o->encoding));
    } else if (!strcasecmp(c->argv[1]->ptr,"idletime") && c->argc == 3) {
        if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.null[c->resp]))
                == NULL) return;
        if (server.maxmemory_policy & MAXMEMORY_FLAG_LFU) {
            addReplyError(c,"An LFU maxmemory policy is selected, idle time not tracked. Please note that when switching between policies at runtime LRU and LFU data will take some time to adjust.");
            return;
        }
        addReplyLongLong(c,estimateObjectIdleTime(o)/1000);
    } else if (!strcasecmp(c->argv[1]->ptr,"freq") && c->argc == 3) {
        if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.null[c->resp]))
                == NULL) return;
        if (!(server.maxmemory_policy & MAXMEMORY_FLAG_LFU)) {
            addReplyError(c,"An LFU maxmemory policy is not selected, access frequency not tracked. Please note that when switching between policies at runtime LRU and LFU data will take some time to adjust.");
            return;
        }
        /* LFUDecrAndReturn should be called
         * in case of the key has not been accessed for a long time,
         * because we update the access time only
         * when the key is read or overwritten. */
        addReplyLongLong(c,LFUDecrAndReturn(o));
    } else {
        addReplySubcommandSyntaxError(c);
    }
}

/* The memory command will eventually be a complete interface for the
 * memory introspection capabilities of Redis.