自学教程：C++ tryObjectEncoding函数代码示例

void pushGenericCommand(redisClient *c, int where) {    int j, waiting = 0, pushed = 0;    robj *lobj = lookupKeyWrite(c->db,c->argv[1]);    if (lobj && lobj->type != REDIS_LIST) {        addReply(c,shared.wrongtypeerr);        return;    }    for (j = 2; j < c->argc; j++) {        c->argv[j] = tryObjectEncoding(c->argv[j]);        if (!lobj) {            lobj = createZiplistObject();            dbAdd(c->db,c->argv[1],lobj);        }        listTypePush(lobj,c->argv[j],where);        pushed++;    }    addReplyLongLong(c, waiting + (lobj ? listTypeLength(lobj) : 0));    if (pushed) {        char *event = (where == REDIS_HEAD) ? "lpush" : "rpush";        signalModifiedKey(c->db,c->argv[1]);        notifyKeyspaceEvent(REDIS_NOTIFY_LIST,event,c->argv[1],c->db->id);    }    server.dirty += pushed;}

// XX 对应的getset实现吗?void setCommand(redisClient *c) {    int j;    robj *expire = NULL;    int unit = UNIT_SECONDS;    int flags = REDIS_SET_NO_FLAGS;    for (j = 3; j < c->argc; j++) {        char *a = c->argv[j]->ptr;        robj *next = (j == c->argc-1) ? NULL : c->argv[j+1];        if ((a[0] == 'n' || a[0] == 'N') &&            (a[1] == 'x' || a[1] == 'X') && a[2] == '/0') {            flags |= REDIS_SET_NX;        } else if ((a[0] == 'x' || a[0] == 'X') &&                   (a[1] == 'x' || a[1] == 'X') && a[2] == '/0') {            flags |= REDIS_SET_XX;        } else if ((a[0] == 'e' || a[0] == 'E') &&                   (a[1] == 'x' || a[1] == 'X') && a[2] == '/0' && next) {            unit = UNIT_SECONDS;            expire = next;            j++;        } else if ((a[0] == 'p' || a[0] == 'P') &&                   (a[1] == 'x' || a[1] == 'X') && a[2] == '/0' && next) {            unit = UNIT_MILLISECONDS;            expire = next;            j++;        } else {            addReply(c,shared.syntaxerr);            return;        }    }    c->argv[2] = tryObjectEncoding(c->argv[2]);    setGenericCommand(c,flags,c->argv[1],c->argv[2],expire,unit,NULL,NULL);}

void pushGenericCommand(redisClient *c, int where) {    robj *lobj = lookupKeyWrite(c->db,c->argv[1]);    c->argv[2] = tryObjectEncoding(c->argv[2]);    if (lobj == NULL) {        if (handleClientsWaitingListPush(c,c->argv[1],c->argv[2])) {            addReply(c,shared.cone);            return;        }        lobj = createZiplistObject();        dbAdd(c->db,c->argv[1],lobj);    } else {        if (lobj->type != REDIS_LIST) {            addReply(c,shared.wrongtypeerr);            return;        }        if (handleClientsWaitingListPush(c,c->argv[1],c->argv[2])) {            touchWatchedKey(c->db,c->argv[1]);            addReply(c,shared.cone);            return;        }    }    listTypePush(lobj,c->argv[2],where);    addReplyLongLong(c,listTypeLength(lobj));    touchWatchedKey(c->db,c->argv[1]);    server.dirty++;}

void pushGenericCommand(redisClient *c, int where) {    int j, addlen = 0, pushed = 0;    robj *lobj = lookupKeyWrite(c->db,c->argv[1]);    int may_have_waiting_clients = (lobj == NULL);    if (lobj && lobj->type != REDIS_LIST) {        addReply(c,shared.wrongtypeerr);        return;    }    for (j = 2; j < c->argc; j++) {        c->argv[j] = tryObjectEncoding(c->argv[j]);        if (may_have_waiting_clients) {            if (handleClientsWaitingListPush(c,c->argv[1],c->argv[j])) {                addlen++;                continue;            } else {                may_have_waiting_clients = 0;            }        }        if (!lobj) {            lobj = createZiplistObject();            dbAdd(c->db,c->argv[1],lobj);        }        listTypePush(lobj,c->argv[j],where);        pushed++;    }    addReplyLongLong(c,addlen + (lobj ? listTypeLength(lobj) : 0));    if (pushed) signalModifiedKey(c->db,c->argv[1]);    server.dirty += pushed;}

void zremCommand(redisClient *c) {    robj *zsetobj;    zset *zs;    dictEntry *de;    double curscore;    int deleted;    if ((zsetobj = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||        checkType(c,zsetobj,REDIS_ZSET)) return;    zs = zsetobj->ptr;    c->argv[2] = tryObjectEncoding(c->argv[2]);    de = dictFind(zs->dict,c->argv[2]);    if (de == NULL) {        addReply(c,shared.czero);        return;    }    /* Delete from the skiplist */    curscore = *(double*)dictGetEntryVal(de);    deleted = zslDelete(zs->zsl,curscore,c->argv[2]);    redisAssert(deleted != 0);    /* Delete from the hash table */    dictDelete(zs->dict,c->argv[2]);    if (htNeedsResize(zs->dict)) dictResize(zs->dict);    if (dictSize(zs->dict) == 0) dbDelete(c->db,c->argv[1]);    touchWatchedKey(c->db,c->argv[1]);    server.dirty++;    addReply(c,shared.cone);}

void zrankGenericCommand(redisClient *c, int reverse) {    robj *o;    zset *zs;    zskiplist *zsl;    dictEntry *de;    unsigned long rank;    double *score;    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||        checkType(c,o,REDIS_ZSET)) return;    zs = o->ptr;    zsl = zs->zsl;    c->argv[2] = tryObjectEncoding(c->argv[2]);    de = dictFind(zs->dict,c->argv[2]);    if (!de) {        addReply(c,shared.nullbulk);        return;    }    score = dictGetEntryVal(de);    rank = zslGetRank(zsl, *score, c->argv[2]);    if (rank) {        if (reverse) {            addReplyLongLong(c, zsl->length - rank);        } else {            addReplyLongLong(c, rank-1);        }    } else {        addReply(c,shared.nullbulk);    }}

void getsetCommand(redisClient *c) {    if (getGenericCommand(c) == REDIS_ERR) return;    c->argv[2] = tryObjectEncoding(c->argv[2]);    setKey(c->db,c->argv[1],c->argv[2]);    notifyKeyspaceEvent(REDIS_NOTIFY_STRING,"set",c->argv[1],c->db->id);    server.dirty++;}

void msetGenericCommand(redisClient *c, int nx) {    int j, busykeys = 0;    if ((c->argc % 2) == 0) {        addReplyError(c,"wrong number of arguments for MSET");        return;    }    /* Handle the NX flag. The MSETNX semantic is to return zero and don't     * set nothing at all if at least one already key exists. */    if (nx) {        for (j = 1; j < c->argc; j += 2) {            if (lookupKeyWrite(c->db,c->argv[j]) != NULL) {                busykeys++;            }        }    }    if (busykeys) {        addReply(c, shared.czero);        return;    }    for (j = 1; j < c->argc; j += 2) {        c->argv[j+1] = tryObjectEncoding(c->argv[j+1]);        dbReplace(c->db,c->argv[j],c->argv[j+1]);        incrRefCount(c->argv[j+1]);        removeExpire(c->db,c->argv[j]);        touchWatchedKey(c->db,c->argv[j]);    }    server.dirty += (c->argc-1)/2;    addReply(c, nx ? shared.cone : shared.ok);}

void msetGenericCommand(redisClient *c, int nx) {    int j, busykeys = 0;    if ((c->argc % 2) == 0) {        addReplyError(c,"wrong number of arguments for MSET");        return;    }    /* Handle the NX flag. The MSETNX semantic is to return zero and don't     * set nothing at all if at least one already key exists. */    if (nx) {        for (j = 1; j < c->argc; j += 2) {            if (lookupKeyWrite(c->db,c->argv[j]) != NULL) {                busykeys++;            }        }        if (busykeys) {            addReply(c, shared.czero);            return;        }    }    for (j = 1; j < c->argc; j += 2) {        c->argv[j+1] = tryObjectEncoding(c->argv[j+1]);        setKey(c->db,c->argv[j],c->argv[j+1]);        notifyKeyspaceEvent(REDIS_NOTIFY_STRING,"set",c->argv[j],c->db->id);    }    server.dirty += (c->argc-1)/2;    addReply(c, nx ? shared.cone : shared.ok);}

void getsetCommand(redisClient *c) {    uint16_t version = sdsversion(c->argv[1]->ptr);    if (getGenericCommand(c) == REDIS_ERR) return;    c->argv[2] = tryObjectEncoding(c->argv[2]);    if (c->returncode == REDIS_OK_NOT_EXIST) {        sdsversion_change(c->argv[1]->ptr, 0);    } else {        if(c->version_care && version != 0 && version != c->version) {            c->returncode = REDIS_ERR_VERSION_ERROR;            return;        } else {            sdsversion_change(c->argv[1]->ptr, c->version);        }    }    if(c->version_care) {        sdsversion_add(c->argv[1]->ptr, 1);    }    dbSuperReplace(c->db,c->argv[1],c->argv[2]);    incrRefCount(c->argv[2]);    c->db->dirty++;    if (c->expiretime > 0) {        setExpire(c->db,c->argv[1],c->expiretime);    } else if(c->expiretime == 0) {        removeXExpire(c->db, c->argv[1]);    }    c->returncode = REDIS_OK;}

void saddCommand(redisClient *c) {    robj *set;    int j, added = 0;    set = lookupKeyWrite(c->db,c->argv[1]);    if (set == NULL) {        set = setTypeCreate(c->argv[2]);        dbAdd(c->db,c->argv[1],set);    } else {        if (set->type != REDIS_SET) {            addReply(c,shared.wrongtypeerr);            return;        }    }    for (j = 2; j < c->argc; j++) {        c->argv[j] = tryObjectEncoding(c->argv[j]);        if (setTypeAdd(set,c->argv[j])) added++;    }    if (added) {        signalModifiedKey(c->db,c->argv[1]);        notifyKeyspaceEvent(REDIS_NOTIFY_SET,"sadd",c->argv[1],c->db->id);    }    server.dirty += added;    addReplyLongLong(c,added);}

void linsertCommand(redisClient *c) {    c->argv[4] = tryObjectEncoding(c->argv[4]);    if (strcasecmp(c->argv[2]->ptr,"after") == 0) {        pushxGenericCommand(c,c->argv[3],c->argv[4],REDIS_TAIL);    } else if (strcasecmp(c->argv[2]->ptr,"before") == 0) {        pushxGenericCommand(c,c->argv[3],c->argv[4],REDIS_HEAD);    } else {        addReply(c,shared.syntaxerr);    }}

void debugCommand(client *c) {    if (!strcasecmp(c->argv[1]->ptr,"segfault")) {        *((char*)-1) = 'x';    } else if (!strcasecmp(c->argv[1]->ptr,"oom")) {        void *ptr = zmalloc(ULONG_MAX); /* Should trigger an out of memory. */        zfree(ptr);        addReply(c,shared.ok);    } else if (!strcasecmp(c->argv[1]->ptr,"assert")) {        if (c->argc >= 3) c->argv[2] = tryObjectEncoding(c->argv[2]);        serverAssertWithInfo(c,c->argv[0],1 == 2);    } else if (!strcasecmp(c->argv[1]->ptr,"flushall")) {        flushServerData();        addReply(c,shared.ok);    } else if (!strcasecmp(c->argv[1]->ptr,"loadaof")) {        flushServerData();        if (loadAppendOnlyFile(server.aof_filename) != C_OK) {            addReply(c,shared.err);            return;        }        serverLog(LL_WARNING,"Append Only File loaded by DEBUG LOADAOF");        addReply(c,shared.ok);    } else if (!strcasecmp(c->argv[1]->ptr,"sleep") && c->argc == 3) {        double dtime = strtod(c->argv[2]->ptr,NULL);        long long utime = dtime*1000000;        struct timespec tv;        tv.tv_sec = utime / 1000000;        tv.tv_nsec = (utime % 1000000) * 1000;        nanosleep(&tv, NULL);        addReply(c,shared.ok);    } else if (!strcasecmp(c->argv[1]->ptr,"error") && c->argc == 3) {        sds errstr = sdsnewlen("-",1);        errstr = sdscatsds(errstr,c->argv[2]->ptr);        errstr = sdsmapchars(errstr,"/n/r","  ",2); /* no newlines in errors. */        errstr = sdscatlen(errstr,"/r/n",2);        addReplySds(c,errstr);    } else if (!strcasecmp(c->argv[1]->ptr,"structsize") && c->argc == 2) {        sds sizes = sdsempty();        sizes = sdscatprintf(sizes,"bits:%d ",(sizeof(void*) == 8)?64:32);        sizes = sdscatprintf(sizes,"job:%d ", (int)sizeof(job));        sizes = sdscatprintf(sizes,"queue:%d ", (int)sizeof(queue));        sizes = sdscatprintf(sizes,"robj:%d ",(int)sizeof(robj));        sizes = sdscatprintf(sizes,"dictentry:%d ",(int)sizeof(dictEntry));        sizes = sdscatprintf(sizes,"sdshdr5:%d ",(int)sizeof(struct sdshdr5));        sizes = sdscatprintf(sizes,"sdshdr8:%d ",(int)sizeof(struct sdshdr8));        sizes = sdscatprintf(sizes,"sdshdr16:%d ",(int)sizeof(struct sdshdr16));        sizes = sdscatprintf(sizes,"sdshdr32:%d ",(int)sizeof(struct sdshdr32));        sizes = sdscatprintf(sizes,"sdshdr64:%d ",(int)sizeof(struct sdshdr64));        addReplyBulkSds(c,sizes);    } else {        addReplyErrorFormat(c, "Unknown DEBUG subcommand or wrong number of arguments for '%s'",                            (char*)c->argv[1]->ptr);    }}

void pushnGenericCommand(redisClient *c, int where) {    /* return_value must be null,otherwise it have memory leak */    c->returncode = REDIS_ERR;    robj *lobj = lookupKeyWriteWithVersion(c->db, c->argv[1], &c->version);    robj* key = c->argv[1];    if(lobj != NULL) {        if(checkType(c, lobj, REDIS_LIST)) {            c->returncode = REDIS_ERR_WRONG_TYPE_ERROR;            return;        }        uint16_t version = sdsversion(key->ptr);        if(c->version_care && version != 0 && version != c->version) {            c->returncode = REDIS_ERR_VERSION_ERROR;            return;        } else {            sdsversion_change(key->ptr, c->version);        }    } else {        sdsversion_change(key->ptr, 0);    }    if(c->version_care) {        sdsversion_add(key->ptr, 1);    }    c->return_value = (void*)zmalloc(sizeof(push_return_value));    if(c->return_value == NULL) {        c->returncode = REDIS_ERR_MEMORY_ALLOCATE_ERROR;        return;    }    int i = 2;    for(; i < c->argc; i++) {        if(lobj == NULL) {            c->argv[i] = tryObjectEncoding(c->argv[i]);            lobj = createZiplistObject();            dbAdd(c->db,c->argv[1],lobj);        }        unsigned long list_len = listTypeLength(lobj);        if (list_len >= (unsigned long)(c->server->list_max_size)) {            break;        }        listTypePush(c,lobj,c->argv[i],where);        c->server->dirty++;    }    if (i != 2) {        dbUpdateKey(c->db, key);        EXPIRE_OR_NOT    }

void sismemberCommand(redisClient *c) {    robj *set;    if ((set = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||        checkType(c,set,REDIS_SET)) return;    c->argv[2] = tryObjectEncoding(c->argv[2]);    if (setTypeIsMember(set,c->argv[2]))        addReply(c,shared.cone);    else        addReply(c,shared.czero);}

void smoveCommand(redisClient *c) {    robj *srcset, *dstset, *ele;    srcset = lookupKeyWrite(c->db,c->argv[1]);    dstset = lookupKeyWrite(c->db,c->argv[2]);    ele = c->argv[3] = tryObjectEncoding(c->argv[3]);    /* If the source key does not exist return 0 */    if (srcset == NULL) {        addReply(c,shared.czero);        return;    }    /* If the source key has the wrong type, or the destination key     * is set and has the wrong type, return with an error. */    if (checkType(c,srcset,REDIS_SET) ||        (dstset && checkType(c,dstset,REDIS_SET))) return;    /* If srcset and dstset are equal, SMOVE is a no-op */    if (srcset == dstset) {        addReply(c,shared.cone);        return;    }    /* If the element cannot be removed from the src set, return 0. */    if (!setTypeRemove(srcset,ele)) {        addReply(c,shared.czero);        return;    }    notifyKeyspaceEvent(REDIS_NOTIFY_SET,"srem",c->argv[1],c->db->id);    /* Remove the src set from the database when empty */    if (setTypeSize(srcset) == 0) {        dbDelete(c->db,c->argv[1]);        notifyKeyspaceEvent(REDIS_NOTIFY_GENERIC,"del",c->argv[1],c->db->id);    }    signalModifiedKey(c->db,c->argv[1]);    signalModifiedKey(c->db,c->argv[2]);    server.dirty++;    /* Create the destination set when it doesn't exist */    if (!dstset) {        dstset = setTypeCreate(ele);        dbAdd(c->db,c->argv[2],dstset);    }    /* An extra key has changed when ele was successfully added to dstset */    if (setTypeAdd(dstset,ele)) {        server.dirty++;        notifyKeyspaceEvent(REDIS_NOTIFY_SET,"sadd",c->argv[2],c->db->id);    }    addReply(c,shared.cone);}

void hashTypeConvertZiplist(robj *o, int enc) {        logicErrorExpr(o->encoding == REDIS_ENCODING_ZIPLIST, "Invalid type");    if (enc == REDIS_ENCODING_ZIPLIST) {        /* Nothing to do... */    } else if (enc == REDIS_ENCODING_HT) {        hashTypeIterator *hi;        dict *dict;        int ret;        hi = hashTypeInitIterator(o);        dict = dictCreate(&hashDictType, NULL);        while (hashTypeNext(hi) != REDIS_ERR) {            robj *field, *value;            field = hashTypeCurrentObject(hi, REDIS_HASH_KEY);            field = tryObjectEncoding(field);            value = hashTypeCurrentObject(hi, REDIS_HASH_VALUE);            value = tryObjectEncoding(value);            ret = dictAdd(dict, field, value);            if (ret != DICT_OK) {//                redisLogHexDump(REDIS_WARNING,"ziplist with dup elements dump",//                    o->ptr,ziplistBlobLen(o->ptr));                logicErrorExpr(ret == DICT_OK, "Never happend");            }        }        hashTypeReleaseIterator(hi);        zfree(o->ptr);        o->encoding = REDIS_ENCODING_HT;        o->ptr = dict;    } else {        logicError("Unknown hash encoding");    }}

// LINSERT key BEFORE|AFTER pivot(基准值) value// LINSERT命令的实现void linsertCommand(client *c) {    //对基准值进行优化编码    c->argv[4] = tryObjectEncoding(c->argv[4]);    //比较where字符串，忽略大小写    if (strcasecmp(c->argv[2]->ptr,"after") == 0) {        //如果是after，则是在基准值的后插入        pushxGenericCommand(c,c->argv[3],c->argv[4],LIST_TAIL);    } else if (strcasecmp(c->argv[2]->ptr,"before") == 0) {        //如果是before，则是在基准值的前插入        pushxGenericCommand(c,c->argv[3],c->argv[4],LIST_HEAD);    } else {        addReply(c,shared.syntaxerr);   //否则发送语法错误信息    }}

void sremCommand(redisClient *c) {    robj *set;    if ((set = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||        checkType(c,set,REDIS_SET)) return;    c->argv[2] = tryObjectEncoding(c->argv[2]);    if (setTypeRemove(set,c->argv[2])) {        if (setTypeSize(set) == 0) dbDelete(c->db,c->argv[1]);        touchWatchedKey(c->db,c->argv[1]);        server.dirty++;        addReply(c,shared.cone);    } else {        addReply(c,shared.czero);    }}

void lremCommand(redisClient *c) {    robj *subject, *obj;    obj = c->argv[3] = tryObjectEncoding(c->argv[3]);    long toremove;    long removed = 0;    listTypeEntry entry;    int slotnum = keyHashSlot(c->argv[1]->ptr, sdslen(c->argv[1]->ptr));    if ((getLongFromObjectOrReply(c, c->argv[2], &toremove, NULL) != REDIS_OK))        return;    subject = lookupKeyWriteOrReply(c,c->argv[1],shared.czero,slotnum);    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],slotnum);    addReplyLongLong(c,removed);    if (removed) signalModifiedKey(c->db,c->argv[1],slotnum);}

void pushGenericCommand(redisClient *c, int where) {    int j, waiting = 0, pushed = 0;    robj *lobj = lookupKeyWrite(c->db,c->argv[1]);    int may_have_waiting_clients = (lobj == NULL);    if (lobj && lobj->type != REDIS_LIST) {        addReply(c,shared.wrongtypeerr);        return;    }    for (j = 2; j < c->argc; j++) {        c->argv[j] = tryObjectEncoding(c->argv[j]);        if (may_have_waiting_clients) {            if (handleClientsWaitingListPush(c,c->argv[1],c->argv[j])) {                waiting++;                continue;            } else {                may_have_waiting_clients = 0;            }        }        if (!lobj) {            lobj = createZiplistObject();            dbAdd(c->db,c->argv[1],lobj);        }        listTypePush(lobj,c->argv[j],where);        pushed++;    }    addReplyLongLong(c, waiting + (lobj ? listTypeLength(lobj) : 0));    if (pushed) signalModifiedKey(c->db,c->argv[1]);    server.dirty += pushed;    /* Alter the replication of the command accordingly to the number of     * list elements delivered to clients waiting into a blocking operation.     * We do that only if there were waiting clients, and only if still some     * element was pushed into the list (othewise dirty is 0 and nothign will     * be propagated). */    if (waiting && pushed) {        /* CMD KEY a b C D E */        for (j = 0; j < waiting; j++) decrRefCount(c->argv[j+2]);        memmove(c->argv+2,c->argv+2+waiting,sizeof(robj*)*pushed);        c->argc -= waiting;    }}

void getsetCommand(redisClient *c) {    if (getGenericCommand(c) == REDIS_ERR) return;#ifdef AUTH_FEATURE    /* Check mod permissions */    if (authCheckModOrReply(c) == REDIS_ERR)      return;    /* Check path permissions */    if (authCheckPathOrReply(c, c->argv[2]) == REDIS_ERR)      return;#endif    c->argv[2] = tryObjectEncoding(c->argv[2]);    dbReplace(c->db,c->argv[1],c->argv[2]);    incrRefCount(c->argv[2]);    touchWatchedKey(c->db,c->argv[1]);    server.dirty++;    removeExpire(c->db,c->argv[1]);}

void zscoreCommand(redisClient *c) {    robj *o;    zset *zs;    dictEntry *de;    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||        checkType(c,o,REDIS_ZSET)) return;    zs = o->ptr;    c->argv[2] = tryObjectEncoding(c->argv[2]);    de = dictFind(zs->dict,c->argv[2]);    if (!de) {        addReply(c,shared.nullbulk);    } else {        double *score = dictGetEntryVal(de);        addReplyDouble(c,*score);    }}

void lsetCommand(redisClient *c) {	int slotnum = keyHashSlot(c->argv[1]->ptr, sdslen(c->argv[1]->ptr));    robj *o = lookupKeyWriteOrReply(c,c->argv[1],shared.nokeyerr,slotnum);    if (o == NULL || checkType(c,o,REDIS_LIST)) return;    long index;    robj *value = (c->argv[3] = tryObjectEncoding(c->argv[3]));    if ((getLongFromObjectOrReply(c, c->argv[2], &index, NULL) != REDIS_OK))        return;    listTypeTryConversion(o,value);    if (o->encoding == REDIS_ENCODING_ZIPLIST) {        unsigned char *p, *zl = o->ptr;        p = ziplistIndex(zl,index);        if (p == NULL) {            addReply(c,shared.outofrangeerr);        } else {            o->ptr = ziplistDelete(o->ptr,&p);            value = getDecodedObject(value);            o->ptr = ziplistInsert(o->ptr,p,value->ptr,sdslen(value->ptr));            decrRefCount(value);            addReply(c,shared.ok);            signalModifiedKey(c->db,c->argv[1],slotnum);            notifyKeyspaceEvent(REDIS_NOTIFY_LIST,"lset",c->argv[1],c->db->id);            server.dirty++;        }    } else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {        listNode *ln = listIndex(o->ptr,index);        if (ln == NULL) {            addReply(c,shared.outofrangeerr);        } else {            decrRefCount((robj*)listNodeValue(ln));            listNodeValue(ln) = value;            incrRefCount(value);            addReply(c,shared.ok);            signalModifiedKey(c->db,c->argv[1],slotnum);            notifyKeyspaceEvent(REDIS_NOTIFY_LIST,"lset",c->argv[1],c->db->id);            server.dirty++;        }    } else {        redisPanic("Unknown list encoding");    }}

//PUSH命令的底层实现，where保存push的位置void pushGenericCommand(client *c, int where) {    int j, waiting = 0, pushed = 0;    robj *lobj = lookupKeyWrite(c->db,c->argv[1]);  //以写操作读取key对象的value    //如果value对象不是列表类型则发送错误信息，返回    if (lobj && lobj->type != OBJ_LIST) {        addReply(c,shared.wrongtypeerr);        return;    }    //从第一个value开始遍历    for (j = 2; j < c->argc; j++) {        c->argv[j] = tryObjectEncoding(c->argv[j]);     //将value对象优化编码        //如果没有找到key对象        if (!lobj) {            //创建一个quicklist类型的对象            lobj = createQuicklistObject();            //设置ziplist最大的长度和压缩程度，配置文件指定            quicklistSetOptions(lobj->ptr, server.list_max_ziplist_size,                                server.list_compress_depth);            //将新的key对象和优化编码过的value对象进行组成键值对            dbAdd(c->db,c->argv[1],lobj);        }        //在where推入一个value对象        listTypePush(lobj,c->argv[j],where);        pushed++;   //更新计数器    }    //发送当前列表中元素的个数    addReplyLongLong(c, waiting + (lobj ? listTypeLength(lobj) : 0));    //如果推入元素成功    if (pushed) {        char *event = (where == LIST_HEAD) ? "lpush" : "rpush";        //当数据库的键被改动，则会调用该函数发送信号        signalModifiedKey(c->db,c->argv[1]);        //发送"lpush"或"rpush"事件通知        notifyKeyspaceEvent(NOTIFY_LIST,event,c->argv[1],c->db->id);    }    server.dirty += pushed; //更新脏键}

void appendCommand(redisClient *c) {    int retval;    size_t totlen;    robj *o;    o = lookupKeyWrite(c->db,c->argv[1]);    c->argv[2] = tryObjectEncoding(c->argv[2]);    if (o == NULL) {        /* Create the key */        retval = dbAdd(c->db,c->argv[1],c->argv[2]);        incrRefCount(c->argv[2]);        totlen = stringObjectLen(c->argv[2]);    } else {        if (o->type != REDIS_STRING) {            addReply(c,shared.wrongtypeerr);            return;        }        /* If the object is specially encoded or shared we have to make         * a copy */        if (o->refcount != 1 || o->encoding != REDIS_ENCODING_RAW) {            robj *decoded = getDecodedObject(o);            o = createStringObject(decoded->ptr, sdslen(decoded->ptr));            decrRefCount(decoded);            dbReplace(c->db,c->argv[1],o);        }        /* APPEND! */        if (c->argv[2]->encoding == REDIS_ENCODING_RAW) {            o->ptr = sdscatlen(o->ptr,                c->argv[2]->ptr, sdslen(c->argv[2]->ptr));        } else {            o->ptr = sdscatprintf(o->ptr, "%ld",                (unsigned long) c->argv[2]->ptr);        }        totlen = sdslen(o->ptr);    }    touchWatchedKey(c->db,c->argv[1]);    server.dirty++;    addReplyLongLong(c,totlen);}

/* zset access is mostly a copy/paste from zscoreCommand() */double zsetScore(robj *zobj, robj *member, double *score) {    if (!zobj || !member)        return false;    if (zobj->encoding == REDIS_ENCODING_ZIPLIST) {        if (zzlFind(zobj->ptr, member, score) == NULL)            return false;    } else if (zobj->encoding == REDIS_ENCODING_SKIPLIST) {        zset *zs = zobj->ptr;        dictEntry *de;        member = tryObjectEncoding(member);        de = dictFind(zs->dict, member);        if (de != NULL) {            *score = *(double *)dictGetVal(de);        } else            return false;    } else {        return false;    }    return true;}

void pushGenericCommand(redisClient *c, int where) {    int j, waiting = 0, pushed = 0;    robj *lobj = lookupKeyWrite(c->db,c->argv[1]);    if (lobj && lobj->type != REDIS_LIST) {        addReply(c,shared.wrongtypeerr);        return;    }    for (j = 2; j < c->argc; j++) {        c->argv[j] = tryObjectEncoding(c->argv[j]);        if (!lobj) {            lobj = createZiplistObject();            dbAdd(c->db,c->argv[1],lobj);        }        listTypePush(lobj,c->argv[j],where);        pushed++;    }    addReplyLongLong(c, waiting + (lobj ? listTypeLength(lobj) : 0));    if (pushed) {        signalModifiedKey(c->db,c->argv[1]);    }}

void saddCommand(redisClient *c) {    robj *set;    set = lookupKeyWrite(c->db,c->argv[1]);    c->argv[2] = tryObjectEncoding(c->argv[2]);    if (set == NULL) {        set = setTypeCreate(c->argv[2]);        dbAdd(c->db,c->argv[1],set);    } else {        if (set->type != REDIS_SET) {            addReply(c,shared.wrongtypeerr);            return;        }    }    if (setTypeAdd(set,c->argv[2])) {        touchWatchedKey(c->db,c->argv[1]);        server.dirty++;        addReply(c,shared.cone);    } else {        addReply(c,shared.czero);    }}