Function createEmbeddedStringObject

src/object.cpp:99–135

Create a string object with encoding OBJ_ENCODING_EMBSTR, that is * an object where the sds string is actually an unmodifiable string * allocated in the same chunk as the object itself. */

 * an object where the sds string is actually an unmodifiable string
 * allocated in the same chunk as the object itself. */
robj *createEmbeddedStringObject(const char *ptr, size_t len) {
    serverAssert(len <= UINT8_MAX);
    // Note: If the size changes update serializeStoredStringObject
    size_t allocsize = sizeof(struct sdshdr8)+len+1;
    if (allocsize < sizeof(void*))
        allocsize = sizeof(void*);

    size_t mvccExtraBytes = g_pserver->fActiveReplica ? sizeof(redisObjectExtended) : 0;
    char *oB = (char*)zmalloc(sizeof(robj)+allocsize-sizeof(redisObject::m_ptr)+mvccExtraBytes, MALLOC_SHARED);
    robj *o = reinterpret_cast<robj*>(oB + mvccExtraBytes);
    struct sdshdr8 *sh = (sdshdr8*)(&o->m_ptr);

    new (o) redisObject;
    o->type = OBJ_STRING;
    o->encoding = OBJ_ENCODING_EMBSTR;
    o->setrefcount(1);
    setMvccTstamp(o, OBJ_MVCC_INVALID);

    if (g_pserver->maxmemory_policy & MAXMEMORY_FLAG_LFU) {
        o->lru = (LFUGetTimeInMinutes()<<8) | LFU_INIT_VAL;
    } else {
        o->lru = LRU_CLOCK();
    }

    sh->len = len;
    sh->alloc = len;
    sh->flags = SDS_TYPE_8;
    if (ptr == SDS_NOINIT)
        sh->buf()[len] = '\0';
    else if (ptr) {
        memcpy(sh->buf(),ptr,len);
        sh->buf()[len] = '\0';
    } else {
        memset(sh->buf(),0,len+1);
    }
    return o;
}

/* Create a string object with EMBSTR encoding if it is smaller than
 * OBJ_ENCODING_EMBSTR_SIZE_LIMIT, otherwise the RAW encoding is