Function rdbGenericLoadStringObject

app/redis-6.2.6/src/rdb.c:508–560

Load a string object from an RDB file according to flags: * * RDB_LOAD_NONE (no flags): load an RDB object, unencoded. * RDB_LOAD_ENC: If the returned type is a Redis object, try to * encode it in a special way to be more memory * efficient. When this flag is passed the function * no longer guarantees that obj->ptr is an SDS string. * RDB_LOAD_PLAIN

 * On I/O error NULL is returned.
 */
void *rdbGenericLoadStringObject(rio *rdb, int flags, size_t *lenptr) {
    int encode = flags & RDB_LOAD_ENC;
    int plain = flags & RDB_LOAD_PLAIN;
    int sds = flags & RDB_LOAD_SDS;
    int isencoded;
    unsigned long long len;

    len = rdbLoadLen(rdb,&isencoded);
    if (len == RDB_LENERR) return NULL;

    if (isencoded) {
        switch(len) {
        case RDB_ENC_INT8:
        case RDB_ENC_INT16:
        case RDB_ENC_INT32:
            return rdbLoadIntegerObject(rdb,len,flags,lenptr);
        case RDB_ENC_LZF:
            return rdbLoadLzfStringObject(rdb,flags,lenptr);
        default:
            rdbReportCorruptRDB("Unknown RDB string encoding type %llu",len);
            return NULL;
        }
    }

    if (plain || sds) {
        void *buf = plain ? ztrymalloc(len) : sdstrynewlen(SDS_NOINIT,len);
        if (!buf) {
            serverLog(server.loading? LL_WARNING: LL_VERBOSE, "rdbGenericLoadStringObject failed allocating %llu bytes", len);
            return NULL;
        }
        if (lenptr) *lenptr = len;
        if (len && rioRead(rdb,buf,len) == 0) {
            if (plain)
                zfree(buf);
            else
                sdsfree(buf);
            return NULL;
        }
        return buf;
    } else {
        robj *o = encode ? tryCreateStringObject(SDS_NOINIT,len) :
                           tryCreateRawStringObject(SDS_NOINIT,len);
        if (!o) {
            serverLog(server.loading? LL_WARNING: LL_VERBOSE, "rdbGenericLoadStringObject failed allocating %llu bytes", len);
            return NULL;
        }
        if (len && rioRead(rdb,o->ptr,len) == 0) {
            decrRefCount(o);
            return NULL;
        }
        return o;
    }
}

robj *rdbLoadStringObject(rio *rdb) {
    return rdbGenericLoadStringObject(rdb,RDB_LOAD_NONE,NULL);