Function dbUnshareStringValue

src/db.cpp:555–564

Prepare the string object stored at 'key' to be modified destructively * to implement commands like SETBIT or APPEND. * * An object is usually ready to be modified unless one of the two conditions * are true: * * 1) The object 'o' is shared (refcount > 1), we don't want to affect * other users. * 2) The object encoding is not "RAW". * * If the object is found in one of the above condi

 * using an sdscat() call to append some data, or anything else.
 */
robj *dbUnshareStringValue(redisDb *db, robj *key, robj *o) {
    serverAssert(o->type == OBJ_STRING);
    if (o->getrefcount(std::memory_order_relaxed) != 1 || o->encoding != OBJ_ENCODING_RAW) {
        robj *decoded = getDecodedObject(o);
        o = createRawStringObject(szFromObj(decoded), sdslen(szFromObj(decoded)));
        decrRefCount(decoded);
        dbOverwrite(db,key,o);
    }
    return o;
}

/* Remove all keys from the database(s) structure. The dbarray argument
 * may not be the server main DBs (could be a backup).