C++ IS_CONSISTENT函数代码示例

// 一个函数覆盖了string-key & index 的情况
// 但他是根据flag做了switch
ZEND_API int zend_hash_del_key_or_index(HashTable *ht, const char *arKey, uint nKeyLength, ulong h, int flag)
{
	uint nIndex;
	Bucket *p;

	IS_CONSISTENT(ht);

	if (flag == HASH_DEL_KEY) {
		h = zend_inline_hash_func(arKey, nKeyLength);
	}
	nIndex = h & ht->nTableMask;

	p = ht->arBuckets[nIndex];
	while (p != NULL) {
		if ((p->h == h) 
			 && (p->nKeyLength == nKeyLength)
			 && ((p->nKeyLength == 0) /* Numeric index (short circuits the memcmp() check) */
				 || !memcmp(p->arKey, arKey, nKeyLength))) { /* String index */
			HANDLE_BLOCK_INTERRUPTIONS();
			if (p == ht->arBuckets[nIndex]) {
				ht->arBuckets[nIndex] = p->pNext;
			} else {
				p->pLast->pNext = p->pNext;
			}
			if (p->pNext) {
				p->pNext->pLast = p->pLast;
			}
			if (p->pListLast != NULL) {
				p->pListLast->pListNext = p->pListNext;
			} else { 
				/* Deleting the head of the list */
				ht->pListHead = p->pListNext;
			}
			if (p->pListNext != NULL) {
				p->pListNext->pListLast = p->pListLast;
			} else {
				ht->pListTail = p->pListLast;
			}
			// array遍历的一致性维护， 指向下一个元素
			// 可能会漏元素吧？？？
			// 没有,怎么做到的?
			if (ht->pInternalPointer == p) {
				ht->pInternalPointer = p->pListNext;
			}
			if (ht->pDestructor) {
				ht->pDestructor(p->pData);
			}
			if (p->pData != &p->pDataPtr) {
				pefree(p->pData, ht->persistent);
			}
			pefree(p, ht->persistent);
			HANDLE_UNBLOCK_INTERRUPTIONS();
			ht->nNumOfElements--;
			return SUCCESS;
		}
		p = p->pNext;
	}
	return FAILURE;
}

ZEND_API void zend_hash_graceful_reverse_destroy(HashTable *ht)
{
	IS_CONSISTENT(ht);

	while (ht->pListTail != NULL) {
		zend_hash_bucket_delete(ht, ht->pListTail);
	}

	if (ht->nTableMask) {
		pefree(ht->arBuckets, ht->persistent);
	}

	SET_INCONSISTENT(HT_DESTROYED);
}

ZEND_API void zend_hash_graceful_destroy(HashTable *ht)
{
	Bucket *p;

	IS_CONSISTENT(ht);

	p = ht->pListHead;
	while (p != NULL) {
		p = zend_hash_apply_deleter(ht, p);
	}
	pefree(ht->arBuckets, ht->persistent);

	SET_INCONSISTENT(HT_DESTROYED);
}

ZEND_API int zend_hash_rehash(HashTable *ht)
{
	Bucket *p;
	uint nIndex;

	IS_CONSISTENT(ht);

	memset(ht->arBuckets, 0, ht->nTableSize * sizeof(Bucket *));
	p = ht->pListHead;
	while (p != NULL) {
		nIndex = p->h & ht->nTableMask;
		CONNECT_TO_BUCKET_DLLIST(p, ht->arBuckets[nIndex]);
		ht->arBuckets[nIndex] = p;
		p = p->pListNext;
	}
	return SUCCESS;
}

ZEND_API void zend_hash_graceful_reverse_destroy(HashTable *ht)
{
    Bucket *p;

    IS_CONSISTENT(ht);

    p = ht->pListTail;
    while (p != NULL) {
        zend_hash_apply_deleter(ht, p);
        p = ht->pListTail;
    }

    if (ht->nTableMask) {
        pefree(ht->arBuckets, ht->persistent);
    }

    SET_INCONSISTENT(HT_DESTROYED);
}

ZEND_API int zend_hash_rehash(HashTable *ht)
{
	Bucket *p;
	uint nIndex;

	IS_CONSISTENT(ht);
	if (UNEXPECTED(ht->nNumOfElements == 0)) {
		return SUCCESS;
	}

	memset(ht->arBuckets, 0, ht->nTableSize * sizeof(Bucket *));
	for (p = ht->pListHead; p != NULL; p = p->pListNext) {
		nIndex = p->h & ht->nTableMask;
		CONNECT_TO_BUCKET_DLLIST(p, ht->arBuckets[nIndex]);
		ht->arBuckets[nIndex] = p;
	}
	return SUCCESS;
}

static void zend_hash_do_resize(HashTable *ht)
{
	Bucket **t;
#ifdef ZEND_SIGNALS
	TSRMLS_FETCH();
#endif

	IS_CONSISTENT(ht);

	if ((ht->nTableSize << 1) > 0) {	/* Let's double the table size */
		t = (Bucket **) perealloc(ht->arBuckets, (ht->nTableSize << 1) * sizeof(Bucket *), ht->persistent);
		HANDLE_BLOCK_INTERRUPTIONS();
		ht->arBuckets = t;
		ht->nTableSize = (ht->nTableSize << 1);
		ht->nTableMask = ht->nTableSize - 1;
		zend_hash_rehash(ht);
		HANDLE_UNBLOCK_INTERRUPTIONS();
	}
}

static int zend_hash_do_resize(HashTable *ht)
{
	Bucket **t;

	IS_CONSISTENT(ht);

	if ((ht->nTableSize << 1) > 0) {	/* Let's double the table size */
		t = (Bucket **) perealloc_recoverable(ht->arBuckets, (ht->nTableSize << 1) * sizeof(Bucket *), ht->persistent);
		if (t) {
			HANDLE_BLOCK_INTERRUPTIONS();
			ht->arBuckets = t;
			ht->nTableSize = (ht->nTableSize << 1);
			ht->nTableMask = ht->nTableSize - 1;
			zend_hash_rehash(ht);
			HANDLE_UNBLOCK_INTERRUPTIONS();
			return SUCCESS;
		}
		return FAILURE;
	}
	return SUCCESS;
}

ZEND_API void zend_hash_apply(HashTable *ht, apply_func_t apply_func TSRMLS_DC)
{
    Bucket *p;

    IS_CONSISTENT(ht);

    HASH_PROTECT_RECURSION(ht);
    p = ht->pListHead;
    while (p != NULL) {
        int result = apply_func(p->pData TSRMLS_CC);

        if (result & ZEND_HASH_APPLY_REMOVE) {
            p = zend_hash_apply_deleter(ht, p);
        } else {
            p = p->pListNext;
        }
        if (result & ZEND_HASH_APPLY_STOP) {
            break;
        }
    }
    HASH_UNPROTECT_RECURSION(ht);
}

/* 对哈希表进行重新哈希操作 */
ZEND_API int zend_hash_rehash(HashTable *ht)
{
	Bucket *p;
	uint nIndex;

	IS_CONSISTENT(ht);
	if (UNEXPECTED(ht->nNumOfElements == 0)) {
		return SUCCESS;
	}
	/* 先将arBuckets重新初始化为0 */
	memset(ht->arBuckets, 0, ht->nTableSize * sizeof(Bucket *));
	/* p指向pListHead，pListHead指向数组的第一个元素，保存这个指针在重新哈希的时候也非常有用
	 */
	p = ht->pListHead;
	while (p != NULL) {
		/* 逐个计算下标然后添加到相同哈希值的bucket中 */
		nIndex = p->h & ht->nTableMask;
		CONNECT_TO_BUCKET_DLLIST(p, ht->arBuckets[nIndex]);
		ht->arBuckets[nIndex] = p;
		p = p->pListNext;
	}
	return SUCCESS;
}

ZEND_API void zend_hash_destroy(HashTable *ht)
{
	Bucket *p, *q;

	IS_CONSISTENT(ht);

	SET_INCONSISTENT(HT_IS_DESTROYING);

	p = ht->pListHead;
	while (p != NULL) {
		q = p;
		p = p->pListNext;
		if (ht->pDestructor) {
			ht->pDestructor(q->pData);
		}
		if (q->pData != &q->pDataPtr) {
			pefree(q->pData, ht->persistent);
		}
		pefree(q, ht->persistent);
	}
	pefree(ht->arBuckets, ht->persistent);

	SET_INCONSISTENT(HT_DESTROYED);
}

ZEND_API void zend_hash_reindex(HashTable *ht, zend_bool only_integer_keys) {
	Bucket *p;
	uint nIndex;
	ulong offset = 0;

	IS_CONSISTENT(ht);
	if (UNEXPECTED(ht->nNumOfElements == 0)) {
		ht->nNextFreeElement = 0;
		return;
	}

	memset(ht->arBuckets, 0, ht->nTableSize * sizeof(Bucket *));
	for (p = ht->pListHead; p != NULL; p = p->pListNext) {
		if (!only_integer_keys || p->nKeyLength == 0) {
			p->h = offset++;
			p->nKeyLength = 0;
		}

		nIndex = p->h & ht->nTableMask;
		CONNECT_TO_BUCKET_DLLIST(p, ht->arBuckets[nIndex]);
		ht->arBuckets[nIndex] = p;
	}
	ht->nNextFreeElement = offset;
}

static zend_always_inline zval *_zend_hash_add_or_update_i(HashTable *ht, zend_string *key, zval *pData, int flag ZEND_FILE_LINE_DC)
{
	zend_uint_t h;
	uint nIndex;
	uint idx;
	Bucket *p;
#ifdef ZEND_SIGNALS
	TSRMLS_FETCH();
#endif

	IS_CONSISTENT(ht);

	CHECK_INIT(ht, 0);
	if (ht->u.flags & HASH_FLAG_PACKED) {
		zend_hash_packed_to_hash(ht);
	}

	h = STR_HASH_VAL(key);

	if ((flag & HASH_ADD_NEW) == 0) {
		p = zend_hash_find_bucket(ht, key);

		if (p) {
			zval *data;

			if (flag & HASH_ADD) {
				return NULL;
			}
			ZEND_ASSERT(&p->val != pData);
			data = &p->val;
			if ((flag & HASH_UPDATE_INDIRECT) && Z_TYPE_P(data) == IS_INDIRECT) {
				data = Z_INDIRECT_P(data);
			}
			HANDLE_BLOCK_INTERRUPTIONS();
			if (ht->pDestructor) {
				ht->pDestructor(data);
			}
			ZVAL_COPY_VALUE(data, pData);
			HANDLE_UNBLOCK_INTERRUPTIONS();
			return data;
		}
	}
	
	ZEND_HASH_IF_FULL_DO_RESIZE(ht);		/* If the Hash table is full, resize it */

	HANDLE_BLOCK_INTERRUPTIONS();
	idx = ht->nNumUsed++;
	ht->nNumOfElements++;
	if (ht->nInternalPointer == INVALID_IDX) {
		ht->nInternalPointer = idx;
	}
	p = ht->arData + idx; 
	p->h = h;
	p->key = key;
	STR_ADDREF(key);
	ZVAL_COPY_VALUE(&p->val, pData);
	nIndex = h & ht->nTableMask;
	Z_NEXT(p->val) = ht->arHash[nIndex];
	ht->arHash[nIndex] = idx;
	HANDLE_UNBLOCK_INTERRUPTIONS();

	return &p->val;
}

ZEND_API void zend_hash_real_init(HashTable *ht, int packed)
{
	IS_CONSISTENT(ht);

	CHECK_INIT(ht, packed);
}

ZEND_API int _zend_hash_index_update_or_next_insert(HashTable *ht, ulong h, void *pData, uint nDataSize, void **pDest, int flag ZEND_FILE_LINE_DC)
{
    uint nIndex;
    Bucket *p;
#ifdef ZEND_SIGNALS
    TSRMLS_FETCH();
#endif

    IS_CONSISTENT(ht);
    CHECK_INIT(ht);

    if (flag & HASH_NEXT_INSERT) {
        h = ht->nNextFreeElement;
    }
    nIndex = h & ht->nTableMask;

    p = ht->arBuckets[nIndex];
    while (p != NULL) {
        if ((p->nKeyLength == 0) && (p->h == h)) {
            if (flag & HASH_NEXT_INSERT || flag & HASH_ADD) {
                return FAILURE;
            }
            HANDLE_BLOCK_INTERRUPTIONS();
#if ZEND_DEBUG
            if (p->pData == pData) {
                ZEND_PUTS("Fatal error in zend_hash_index_update: p->pData == pData\n");
                HANDLE_UNBLOCK_INTERRUPTIONS();
                return FAILURE;
            }
#endif
            if (ht->pDestructor) {
                ht->pDestructor(p->pData);
            }
            UPDATE_DATA(ht, p, pData, nDataSize);
            HANDLE_UNBLOCK_INTERRUPTIONS();
            if ((long)h >= (long)ht->nNextFreeElement) {
                ht->nNextFreeElement = h < LONG_MAX ? h + 1 : LONG_MAX;
            }
            if (pDest) {
                *pDest = p->pData;
            }
            return SUCCESS;
        }
        p = p->pNext;
    }
    p = (Bucket *) pemalloc_rel(sizeof(Bucket), ht->persistent);
    if (!p) {
        return FAILURE;
    }
    p->arKey = NULL;
    p->nKeyLength = 0; /* Numeric indices are marked by making the nKeyLength == 0 */
    p->h = h;
    INIT_DATA(ht, p, pData, nDataSize);
    if (pDest) {
        *pDest = p->pData;
    }

    CONNECT_TO_BUCKET_DLLIST(p, ht->arBuckets[nIndex]);

    HANDLE_BLOCK_INTERRUPTIONS();
    ht->arBuckets[nIndex] = p;
    CONNECT_TO_GLOBAL_DLLIST(p, ht);
    HANDLE_UNBLOCK_INTERRUPTIONS();

    if ((long)h >= (long)ht->nNextFreeElement) {
        ht->nNextFreeElement = h < LONG_MAX ? h + 1 : LONG_MAX;
    }
    ht->nNumOfElements++;
    ZEND_HASH_IF_FULL_DO_RESIZE(ht);
    return SUCCESS;
}