Function hashTypeDup

src/t_hash.cpp:515–553

This is a helper function for the COPY command. * Duplicate a hash object, with the guarantee that the returned object * has the same encoding as the original one. * * The resulting object always has refcount set to 1 */

 *
 * The resulting object always has refcount set to 1 */
robj *hashTypeDup(robj *o) {
    robj *hobj;
    hashTypeIterator *hi;

    serverAssert(o->type == OBJ_HASH);

    if(o->encoding == OBJ_ENCODING_ZIPLIST){
        unsigned char *zl = (unsigned char*)ptrFromObj(o);
        size_t sz = ziplistBlobLen(zl);
        unsigned char *new_zl = (unsigned char*)zmalloc(sz);
        memcpy(new_zl, zl, sz);
        hobj = createObject(OBJ_HASH, new_zl);
        hobj->encoding = OBJ_ENCODING_ZIPLIST;
    } else if(o->encoding == OBJ_ENCODING_HT){
        dict *d = dictCreate(&hashDictType, NULL);
        dictExpand(d, dictSize((const dict*)ptrFromObj(o)));

        hi = hashTypeInitIterator(o);
        while (hashTypeNext(hi) != C_ERR) {
            sds field, value;
            sds newfield, newvalue;
            /* Extract a field-value pair from an original hash object.*/
            field = hashTypeCurrentFromHashTable(hi, OBJ_HASH_KEY);
            value = hashTypeCurrentFromHashTable(hi, OBJ_HASH_VALUE);
            newfield = sdsdup(field);
            newvalue = sdsdup(value);

            /* Add a field-value pair to a new hash object. */
            dictAdd(d,newfield,newvalue);
        }
        hashTypeReleaseIterator(hi);

        hobj = createObject(OBJ_HASH, d);
        hobj->encoding = OBJ_ENCODING_HT;
    } else {
        serverPanic("Unknown hash encoding");
    }
    return hobj;
}

struct hash_ziplist_data {
    long count;