C++ dbDelete函数代码示例

void spopCommand(redisClient *c) {
    robj *set, *ele;
    int64_t llele;
    int encoding;

    if ((set = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
        checkType(c,set,REDIS_SET)) return;

    encoding = setTypeRandomElement(set,&ele,&llele);
    if (encoding == REDIS_ENCODING_INTSET) {
        addReplyBulkLongLong(c,llele);
        set->ptr = intsetRemove(set->ptr,llele,NULL);
    } else {
        addReplyBulk(c,ele);
        setTypeRemove(set,ele);
    }
    if (setTypeSize(set) == 0) dbDelete(c->db,c->argv[1]);
    touchWatchedKey(c->db,c->argv[1]);
    server.dirty++;
}

void expireGenericCommand(redisClient *c, robj *key, robj *param, long offset) {
    dictEntry *de;
    long seconds;

    if (getLongFromObjectOrReply(c, param, &seconds, NULL) != REDIS_OK) return;

    seconds -= offset;

    de = dictFind(c->db->dict,key->ptr);
    if (de == NULL) {
        addReply(c,shared.czero);
        return;
    }
    /* EXPIRE with negative TTL, or EXPIREAT with a timestamp into the past
     * should never be executed as a DEL when load the AOF or in the context
     * of a slave instance.
     *
     * Instead we take the other branch of the IF statement setting an expire
     * (possibly in the past) and wait for an explicit DEL from the master. */
    if (seconds <= 0 && !server.loading && !server.masterhost) {
        robj *aux;

        redisAssert(dbDelete(c->db,key));
        server.dirty++;

        /* Replicate/AOF this as an explicit DEL. */
        aux = createStringObject("DEL",3);
        rewriteClientCommandVector(c,2,aux,key);
        decrRefCount(aux);
        touchWatchedKey(c->db,key);
        addReply(c, shared.cone);
        return;
    } else {
        time_t when = time(NULL)+seconds;
        setExpire(c->db,key,when);
        addReply(c,shared.cone);
        touchWatchedKey(c->db,key);
        server.dirty++;
        return;
    }
}

void moveCommand(redisClient *c) {
    robj *o;
    redisDb *src, *dst;
    int srcid;

    /* Obtain source and target DB pointers */
    src = c->db;
    srcid = c->db->id;
    if (selectDb(c,atoi(c->argv[2]->ptr)) == REDIS_ERR) {
        addReply(c,shared.outofrangeerr);
        return;
    }
    dst = c->db;
    selectDb(c,srcid); /* Back to the source DB */

    /* If the user is moving using as target the same
     * DB as the source DB it is probably an error. */
    if (src == dst) {
        addReply(c,shared.sameobjecterr);
        return;
    }

    /* Check if the element exists and get a reference */
    o = lookupKeyWrite(c->db,c->argv[1]);
    if (!o) {
        addReply(c,shared.czero);
        return;
    }

    /* Try to add the element to the target DB */
    if (dbAdd(dst,c->argv[1],o) == REDIS_ERR) {
        addReply(c,shared.czero);
        return;
    }
    incrRefCount(o);

    /* OK! key moved, free the entry in the source DB */
    dbDelete(src,c->argv[1]);
    server.dirty++;
    addReply(c,shared.cone);
}

void zremrangebyscoreCommand(redisClient *c) {
    double min;
    double max;
    long deleted;
    robj *zsetobj;
    zset *zs;

    if ((getDoubleFromObjectOrReply(c, c->argv[2], &min, NULL) != REDIS_OK) ||
        (getDoubleFromObjectOrReply(c, c->argv[3], &max, NULL) != REDIS_OK)) return;

    if ((zsetobj = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
        checkType(c,zsetobj,REDIS_ZSET)) return;

    zs = zsetobj->ptr;
    deleted = zslDeleteRangeByScore(zs->zsl,min,max,zs->dict);
    if (htNeedsResize(zs->dict)) dictResize(zs->dict);
    if (dictSize(zs->dict) == 0) dbDelete(c->db,c->argv[1]);
    if (deleted) touchWatchedKey(c->db,c->argv[1]);
    server.dirty += deleted;
    addReplyLongLong(c,deleted);
}

void lremCommand(redisClient *c) {
    robj *subject, *obj;
    obj = c->argv[3] = tryObjectEncoding(c->argv[3]);
    int toremove = atoi(c->argv[2]->ptr);
    int removed = 0;
    listTypeEntry entry;

    subject = lookupKeyWriteOrReply(c,c->argv[1],shared.czero);
    if (subject == NULL || checkType(c,subject,REDIS_LIST)) return;

    /* Make sure obj is raw when we're dealing with a ziplist */
    if (subject->encoding == REDIS_ENCODING_ZIPLIST)
        obj = getDecodedObject(obj);

    listTypeIterator *li;
    if (toremove < 0) {
        toremove = -toremove;
        li = listTypeInitIterator(subject,-1,REDIS_HEAD);
    } else {
        li = listTypeInitIterator(subject,0,REDIS_TAIL);
    }

    while (listTypeNext(li,&entry)) {
        if (listTypeEqual(&entry,obj)) {
            listTypeDelete(&entry);
            server.dirty++;
            removed++;
            if (toremove && removed == toremove) break;
        }
    }
    listTypeReleaseIterator(li);

    /* Clean up raw encoded object */
    if (subject->encoding == REDIS_ENCODING_ZIPLIST)
        decrRefCount(obj);

    if (listTypeLength(subject) == 0) dbDelete(c->db,c->argv[1]);
    addReplyLongLong(c,removed);
    if (removed) signalModifiedKey(c->db,c->argv[1]);
}

void popGenericCommand(redisClient *c, int where) {
    robj *o = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk);
    if (o == NULL || checkType(c,o,REDIS_LIST)) return;

    robj *value = listTypePop(o,where);
    if (value == NULL) {
        addReply(c,shared.nullbulk);
    } else {
        char *event = (where == REDIS_HEAD) ? "lpop" : "rpop";

        addReplyBulk(c,value);
        decrRefCount(value);
        notifyKeyspaceEvent(REDIS_NOTIFY_LIST,event,c->argv[1],c->db->id);
        if (listTypeLength(o) == 0) {
            notifyKeyspaceEvent(REDIS_NOTIFY_GENERIC,"del",
                                c->argv[1],c->db->id);
            dbDelete(c->db,c->argv[1]);
        }
        signalModifiedKey(c->db,c->argv[1]);
        server.dirty++;
    }
}

void rpoplpushCommand(redisClient *c) {
    robj *sobj, *value;
    if ((sobj = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
        checkType(c,sobj,REDIS_LIST)) return;

    if (listTypeLength(sobj) == 0) {
        addReply(c,shared.nullbulk);
    } else {
        robj *dobj = lookupKeyWrite(c->db,c->argv[2]);
        if (dobj && checkType(c,dobj,REDIS_LIST)) return;
        value = listTypePop(sobj,REDIS_TAIL);
        rpoplpushHandlePush(c,c->argv[2],dobj,value);

        /* listTypePop returns an object with its refcount incremented */
        decrRefCount(value);

        /* Delete the source list when it is empty */
        if (listTypeLength(sobj) == 0) dbDelete(c->db,c->argv[1]);
        touchWatchedKey(c->db,c->argv[1]);
        server.dirty++;
    }
}

void sremCommand(redisClient *c) {
    robj *set;
    int j, deleted = 0;

    if ((set = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
        checkType(c,set,REDIS_SET)) return;

    for (j = 2; j < c->argc; j++) {
        if (setTypeRemove(set,c->argv[j])) {
            deleted++;
            if (setTypeSize(set) == 0) {
                dbDelete(c->db,c->argv[1]);
                break;
            }
        }
    }
    if (deleted) {
        signalModifiedKey(c->db,c->argv[1]);
        server.dirty += deleted;
    }
    addReplyLongLong(c,deleted);
}

int expireIfNeeded(redisDb *db, robj *key) {
    mstime_t when = getExpire(db,key);//微秒
    mstime_t now;

    if (when < 0) return 0; /* No expire for this key */

    /* Don't expire anything while loading. It will be done later. */
    if (server.loading) return 0;

    /* If we are in the context of a Lua script, we claim that time is
     * blocked to when the Lua script started. This way a key can expire
     * only the first time it is accessed and not in the middle of the
     * script execution, making propagation to slaves / AOF consistent.
     * See issue #1525 on Github for more information. */
    now = server.lua_caller ? server.lua_time_start : mstime();

    /* If we are running in the context of a slave, return ASAP:
     * the slave key expiration is controlled by the master that will
     * send us synthesized DEL operations for expired keys.
     *
     * Still we try to return the right information to the caller,
     * that is, 0 if we think the key should be still valid, 1 if
     * we think the key is expired at this time. */
    if (server.masterhost != NULL) return now > when;

    /* Return when this key has not expired */
    if (now <= when) return 0;

    /* Delete the key */
    server.stat_expiredkeys++;

    propagateExpire(db,key);
    //事件函数的处理
    notifyKeyspaceEvent(REDIS_NOTIFY_EXPIRED,
                        "expired",key,db->id);
    //删除该键
    return dbDelete(db,key);
}

void rpoplpushCommand(redisClient *c) {
    robj *sobj, *value;
    int slotnum1 = keyHashSlot(c->argv[1]->ptr, sdslen(c->argv[1]->ptr));
    int slotnum2 = keyHashSlot(c->argv[2]->ptr, sdslen(c->argv[2]->ptr));
    if ((sobj = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk,slotnum1)) == NULL ||
        checkType(c,sobj,REDIS_LIST)) return;

    if (listTypeLength(sobj) == 0) {
        /* This may only happen after loading very old RDB files. Recent
         * versions of Redis delete keys of empty lists. */
        addReply(c,shared.nullbulk);
    } else {
        robj *dobj = lookupKeyWrite(c->db,c->argv[2],slotnum2);
        robj *touchedkey = c->argv[1];

        if (dobj && checkType(c,dobj,REDIS_LIST)) return;
        value = listTypePop(sobj,REDIS_TAIL);
        /* We saved touched key, and protect it, since rpoplpushHandlePush
         * may change the client command argument vector (it does not
         * currently). */
        incrRefCount(touchedkey);
        rpoplpushHandlePush(c,c->argv[2],dobj,value,slotnum2);

        /* listTypePop returns an object with its refcount incremented */
        decrRefCount(value);

        /* Delete the source list when it is empty */
        notifyKeyspaceEvent(REDIS_NOTIFY_LIST,"rpop",touchedkey,c->db->id);
        if (listTypeLength(sobj) == 0) {
            dbDelete(c->db,touchedkey,slotnum1);
            notifyKeyspaceEvent(REDIS_NOTIFY_GENERIC,"del",
                                touchedkey,c->db->id);
        }
        signalModifiedKey(c->db,touchedkey,slotnum1);
        decrRefCount(touchedkey);
        server.dirty++;
    }
}

void zremrangebyrankCommand(redisClient *c) {
    long start;
    long end;
    int llen;
    long deleted;
    robj *zsetobj;
    zset *zs;

    if ((getLongFromObjectOrReply(c, c->argv[2], &start, NULL) != REDIS_OK) ||
        (getLongFromObjectOrReply(c, c->argv[3], &end, NULL) != REDIS_OK)) return;

    if ((zsetobj = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
        checkType(c,zsetobj,REDIS_ZSET)) return;
    zs = zsetobj->ptr;
    llen = zs->zsl->length;

    /* convert negative indexes */
    if (start < 0) start = llen+start;
    if (end < 0) end = llen+end;
    if (start < 0) start = 0;

    /* Invariant: start >= 0, so this test will be true when end < 0.
     * The range is empty when start > end or start >= length. */
    if (start > end || start >= llen) {
        addReply(c,shared.czero);
        return;
    }
    if (end >= llen) end = llen-1;

    /* increment start and end because zsl*Rank functions
     * use 1-based rank */
    deleted = zslDeleteRangeByRank(zs->zsl,start+1,end+1,zs->dict);
    if (htNeedsResize(zs->dict)) dictResize(zs->dict);
    if (dictSize(zs->dict) == 0) dbDelete(c->db,c->argv[1]);
    if (deleted) touchWatchedKey(c->db,c->argv[1]);
    server.dirty += deleted;
    addReplyLongLong(c, deleted);
}

void zremrangebyscoreCommand(redisClient *c) {
    zrangespec range;
    long deleted;
    robj *o;
    zset *zs;

    /* Parse the range arguments. */
    if (zslParseRange(c->argv[2],c->argv[3],&range) != REDIS_OK) {
        addReplyError(c,"min or max is not a double");
        return;
    }

    if ((o = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||
        checkType(c,o,REDIS_ZSET)) return;

    zs = o->ptr;
    deleted = zslDeleteRangeByScore(zs->zsl,range,zs->dict);
    if (htNeedsResize(zs->dict)) dictResize(zs->dict);
    if (dictSize(zs->dict) == 0) dbDelete(c->db,c->argv[1]);
    if (deleted) touchWatchedKey(c->db,c->argv[1]);
    server.dirty += deleted;
    addReplyLongLong(c,deleted);
}

void rpoplpushCommand(redisClient *c) {
    robj *sobj, *value;
    if ((sobj = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||
        checkType(c,sobj,REDIS_LIST)) return;

    if (listTypeLength(sobj) == 0) {
        /* This may only happen after loading very old RDB files. Recent
         * versions of Redis delete keys of empty lists. */
        addReply(c,shared.nullbulk);
    } else {
        robj *dobj = lookupKeyWrite(c->db,c->argv[2]);
        robj *touchedkey = c->argv[1];

        if (dobj && checkType(c,dobj,REDIS_LIST)) return;
        value = listTypePop(sobj,REDIS_TAIL);
        /* We saved touched key, and protect it, since rpoplpushHandlePush
         * may change the client command argument vector. */
        incrRefCount(touchedkey);
        rpoplpushHandlePush(c,c,c->argv[2],dobj,value);

        /* listTypePop returns an object with its refcount incremented */
        decrRefCount(value);

        /* Delete the source list when it is empty */
        if (listTypeLength(sobj) == 0) dbDelete(c->db,touchedkey);
        signalModifiedKey(c->db,touchedkey);
        decrRefCount(touchedkey);
        server.dirty++;

        /* Replicate this as a simple RPOP since the LPUSH side is replicated
         * by rpoplpushHandlePush() call if needed (it may not be needed
         * if a client is blocking wait a push against the list). */
        rewriteClientCommandVector(c,2,
            resetRefCount(createStringObject("RPOP",4)),
            c->argv[1]);
    }
}

int expireIfNeeded(redisDb *db, robj *key) {
    time_t when = getExpire(db,key);

    if (when < 0) return 0; /* No expire for this key */

    /* If we are running in the context of a slave, return ASAP:
     * the slave key expiration is controlled by the master that will
     * send us synthesized DEL operations for expired keys.
     *
     * Still we try to return the right information to the caller, 
     * that is, 0 if we think the key should be still valid, 1 if
     * we think the key is expired at this time. */
    if (server.masterhost != NULL) {
        return time(NULL) > when;
    }

    /* Return when this key has not expired */
    if (time(NULL) <= when) return 0;

    /* Delete the key */
    server.stat_expiredkeys++;
    propagateExpire(db,key);
    return dbDelete(db,key);
}

void delCommand(redisClient *c) {
    int deleted = 0, j;

    for (j = 1; j < c->argc; j++) {
        if (server.ds_enabled) {
            lookupKeyRead(c->db,c->argv[j]);
            /* FIXME: this can be optimized a lot, no real need to load
             * a possibly huge value. */
        }
        if (dbDelete(c->db,c->argv[j])) {
            signalModifiedKey(c->db,c->argv[j]);
            server.dirty++;
            deleted++;
        } else if (server.ds_enabled) {
            if (cacheKeyMayExist(c->db,c->argv[j]) &&
                dsExists(c->db,c->argv[j]))
            {
                cacheScheduleIO(c->db,c->argv[j],REDIS_IO_SAVE);
                deleted = 1;
            }
        }
    }
    addReplyLongLong(c,deleted);
}