PHP底层的高性能数据结构与实现方法

PHP底层的高性能数据结构与实现方法，需要具体代码示例

随着互联网应用的不断发展，PHP已经成为了一种广泛使用的服务器端脚本语言。然而，在大规模的Web应用中，PHP的性能问题成为了一个不容忽视的问题，很多大型网站都出现了性能瓶颈和系统崩溃的情况。

为了提高PHP的性能，我们需要了解PHP底层的高性能数据结构与实现方法。本文将介绍PHP的几种高性能数据结构及其实现方法，并提供相应的代码示例，帮助读者深入理解PHP的性能优化。

1. 数组

在PHP中，数组是最常用的数据结构之一。不过，PHP的数组实现采用了哈希表的方式，这会带来一些性能上的开销，特别是在对大量数据进行迭代操作时。

为了提高PHP的数组性能，我们可以使用C语言扩展来实现。

下面是一个简单的PHP扩展示例，该扩展实现了一个高性能的哈希表，可以用于存储大量的数据，并且支持各种数据类型的存储和访问。

typedef struct {
    zend_ulong h;
    zval data;
} hashtable_entry;

typedef struct {
    hashtable_entry *table;
    zend_ulong num_entries;
    zend_ulong max_entries;
    zend_ulong rehash_pos;
    zend_ulong rehash_size;
} hashtable;

typedef struct {
    zend_object std;
    hashtable *ht;
} hash_table_object;

static zend_object *hash_table_object_new(zend_class_entry *class_type)
{
    hash_table_object *intern = 
        (hash_table_object *)ecalloc(1, sizeof(hash_table_object));
    zend_object_std_init(&intern->std, class_type);
    object_properties_init(&intern->std, class_type);
    intern->std.handlers = &hash_table_object_handlers;
    intern->ht = 
        (hashtable *)emalloc(sizeof(hashtable));
    return &intern->std;
}

static void hash_table_object_free(zend_object *object)
{
    hash_table_object *intern = 
        hash_table_object_from_obj(object);
    if (intern->ht != NULL) {
        zend_ulong i;
        for (i = 0; i < intern->ht->max_entries; i++) {
            zval_dtor(
                &intern->ht->table[i].data
            );
        }
        efree(intern->ht->table);
        efree(intern->ht);
    }
    zend_object_std_dtor(object);
}

static void hash_table_put(hash_table_object *intern, 
                           zval *key, 
                           zval *value)
{
    zend_ulong idx;
    zend_string *str_key;
    if (Z_TYPE_P(key) == IS_STRING) {
        str_key = Z_STR_P(key);
        idx = zend_inline_hash_func(
            str_key->val, str_key->len
        ) % intern->ht->max_entries;
    } else if (Z_TYPE_P(key) == IS_LONG) {
        idx = Z_LVAL_P(key) % intern->ht->max_entries;
    } else if (Z_TYPE_P(key) == IS_DOUBLE) {
        idx = zend_dval_to_lval(Z_DVAL_P(key)) % intern->ht->max_entries;
    } else if (Z_TYPE_P(key) == IS_TRUE) {
        idx = 1 % intern->ht->max_entries;
    } else {
        idx = 0;
    }
    if (Z_TYPE(intern->ht->table[idx].data) != IS_NULL) {
        zval_dtor(
            &intern->ht->table[idx].data
        );
    }
    intern->ht->table[idx].h = idx;
    ZVAL_COPY_VALUE(
        &intern->ht->table[idx].data, value
    );
}

static zval *hash_table_get(hash_table_object *intern, 
                             zval *key)
{
    zend_ulong idx;
    zend_string *str_key;
    if (Z_TYPE_P(key) == IS_STRING) {
        str_key = Z_STR_P(key);
        idx = zend_inline_hash_func(
            str_key->val, str_key->len
        ) % intern->ht->max_entries;
    } else if (Z_TYPE_P(key) == IS_LONG) {
        idx = Z_LVAL_P(key) % intern->ht->max_entries;
    } else if (Z_TYPE_P(key) == IS_DOUBLE) {
        idx = zend_dval_to_lval(Z_DVAL_P(key)) % intern->ht->max_entries;
    } else if (Z_TYPE_P(key) == IS_TRUE) {
        idx = 1 % intern->ht->max_entries;
    } else {
        idx = 0;
    }
    if (Z_TYPE(intern->ht->table[idx].data) == IS_NULL) {
        return NULL;
    } else {
        return &intern->ht->table[idx].data;
    }
}

static zend_class_entry *hash_table_class_entry;

static zend_function_entry hash_table_methods[] = {
    PHP_ME(HashTable, put, arginfo_hashtable_put, ZEND_ACC_PUBLIC)
    PHP_ME(HashTable, get, arginfo_hashtable_get, ZEND_ACC_PUBLIC)
    PHP_FE_END
};

static zend_object_handlers hash_table_object_handlers;

static void hash_table_object_init(zend_class_entry *class_type)
{
    hash_table_object_handlers = 
        *zend_get_std_object_handlers();
    hash_table_object_handlers.offset = 
        XtOffsetOf(hash_table_object, std);
    hash_table_object_handlers.free_obj = 
        hash_table_object_free;
    hash_table_object_handlers.clone_obj = 
        zend_objects_clone_obj;
}

PHP_MINIT_FUNCTION(hash_table)
{
    zend_class_entry ce;
    INIT_CLASS_ENTRY(ce, "HashTable", hash_table_methods);
    hash_table_class_entry = zend_register_internal_class(&ce);
    hash_table_class_entry->create_object =
        hash_table_object_new;
    hash_table_object_init(
        hash_table_class_entry
    );
    return SUCCESS;
}

使用上述扩展，可以极大地提高PHP数组的性能，尤其适用于大规模数据的处理。

2. 堆

堆是一种常用的数据结构，可以用于优先队列、排序等操作。为了提高PHP的性能，我们可以使用C语言扩展来实现堆数据结构。

下面是一个简单的PHP扩展示例，该扩展实现了一个最小堆，可以用于排序、搜索等操作。

typedef struct {
    zend_ulong size;
    zend_ulong capacity;
    zval *data;
} min_heap;

static min_heap *min_heap_new()
{
    min_heap *heap = emalloc(sizeof(min_heap));
    heap->size = 0;
    heap->capacity = 4;
    heap->data = emalloc(sizeof(zval) * heap->capacity);
    return heap;
}

static void min_heap_free(min_heap *heap)
{
    zend_ulong i;
    for (i = 0; i < heap->size; i++) {
        zval_dtor(&heap->data[i]);
    }
    efree(heap->data);
    efree(heap);
}

static void min_heap_push(min_heap *heap, zval *value)
{
    if (heap->size + 1 > heap->capacity) {
        heap->capacity *= 2;
        heap->data = 
            erealloc(heap->data, sizeof(zval) * heap->capacity);
    }
    zend_ulong hole = ++heap->size;
    while (hole > 1 && 
           zend_is_smaller(
               value, &heap->data[hole / 2]
           )) {
        ZVAL_COPY(
            &heap->data[hole], &heap->data[hole / 2]
        );
        hole /= 2;
    }
    ZVAL_COPY(
        &heap->data[hole], value
    );
}

static void min_heap_pop(min_heap *heap)
{
    zend_ulong hole = 1;
    zend_ulong child = 2;
    zval tmp;
    ZVAL_NULL(&tmp);
    zval_dtor(
        &heap->data[1]
    );
    heap->data[1] = heap->data[heap->size--];
    while (child <= heap->size) {
        if (child < heap->size && 
            zend_is_smaller(&heap->data[child + 1], &heap->data[child])) {
            child++;
        }
        if (zend_is_smaller(&heap->data[child], &heap->data[hole])) {
            ZVAL_COPY(
                &tmp, &heap->data[hole]
            );
            ZVAL_COPY(
                &heap->data[hole], &heap->data[child]
            );
            ZVAL_COPY(
                &heap->data[child], &tmp
            );
        } else {
            break;
        }
        hole = child;
        child *= 2;
    }
}

static zval *min_heap_top(min_heap *heap)
{
    if (heap->size > 0) {
        return &heap->data[1];
    } else {
        return NULL;
    }
}

static zend_class_entry *min_heap_class_entry;

static zend_function_entry min_heap_methods[] = {
    PHP_ME(MinHeap, push, arginfo_min_heap_push, ZEND_ACC_PUBLIC)
    PHP_ME(MinHeap, pop, arginfo_min_heap_pop, ZEND_ACC_PUBLIC)
    PHP_ME(MinHeap, top, arginfo_min_heap_top, ZEND_ACC_PUBLIC)
    PHP_FE_END
};

static zend_object_handlers min_heap_object_handlers;

static void min_heap_object_init(zend_class_entry *class_type)
{
    min_heap_object_handlers = 
        *zend_get_std_object_handlers();
    min_heap_object_handlers.offset = 
        XtOffsetOf(min_heap_object, std);
    min_heap_object_handlers.free_obj = 
        min_heap_object_free;
    min_heap_object_handlers.clone_obj = 
        zend_objects_clone_obj;
}

static zend_object *min_heap_object_new(zend_class_entry *class_type)
{
    min_heap_object *intern = 
        (min_heap_object *)ecalloc(1, sizeof(min_heap_object));
    zend_object_std_init(&intern->std, class_type);
    object_properties_init(&intern->std, class_type);
    intern->std.handlers = &min_heap_object_handlers;
    intern->heap = 
        min_heap_new();
    return &intern->std;
}

static void min_heap_object_free(zend_object *object)
{
    min_heap_object *intern = 
        min_heap_object_from_obj(object);
    if (intern->heap != NULL) {
        min_heap_free(intern->heap);
    }
    zend_object_std_dtor(object);
}

PHP_MINIT_FUNCTION(min_heap)
{
    zend_class_entry ce;
    INIT_CLASS_ENTRY(ce, "MinHeap", min_heap_methods);
    min_heap_class_entry = zend_register_internal_class(&ce);
    min_heap_class_entry->create_object =
        min_heap_object_new;
    min_heap_object_init(
        min_heap_class_entry
    );
    return SUCCESS;
}

使用上述扩展，可以轻松地实现PHP中的堆数据结构，并提高PHP的排序、搜索等操作的性能。

3. 队列

PHP中的队列是一种常见的数据结构，可以用于多线程任务的管理等应用场景。为了提高PHP的性能，我们可以使用C语言扩展来实现队列数据结构。

下面是一个简单的PHP扩展示例，该扩展实现了一个高性能的队列，可以用于多线程任务的处理等应用场景。

typedef struct {
    zend_ulong head;
    zend_ulong tail;
    zend_ulong size;
    zend_ulong capacity;
    zval *data;
} queue;

static queue *queue_new()
{
    queue *q = emalloc(sizeof(queue));
    q->head = 0;
    q->tail = 0;
    q->size = 0;
    q->capacity = 4;
    q->data = emalloc(sizeof(zval) * q->capacity);
    return q;
}

static void queue_free(queue *q)
{
    zend_ulong i;
    for (i = q->head; i != q->tail; i = (i + 1) % q->capacity) {
        zval_dtor(&q->data[i]);
    }
    efree(q->data);
    efree(q);
}

static void queue_push(queue *q, zval *val)
{
    if (q->size >= q->capacity) {
        zend_ulong new_capacity = q->capacity * 2;
        zval *new_data = emalloc(sizeof(zval) * new_capacity);
        zend_ulong i;
        for (i = q->head; i != q->tail; i = (i + 1) % q->capacity) {
            ZVAL_COPY(&new_data[i], &q->data[i]);
        }
        efree(q->data);
        q->data = new_data;
        q->capacity = new_capacity;
        q->head = 0;
        q->tail = q->size;
    }
    ZVAL_COPY(&q->data[q->tail], val);
    q->tail = (q->tail + 1) % q->capacity;
    q->size++;
}

static void queue_pop(queue *q)
{
    if (q->size > 0) {
        zval_dtor(&q->data[q->head]);
        q->head = (q->head + 1) % q->capacity;
        q->size--;
    }
}

static zval *queue_front(queue *q)
{
    if (q->size > 0) {
        return &q->data[q->head];
    } else {
        return NULL;
    }
}

static zend_class_entry *queue_class_entry;

static zend_function_entry queue_methods[] = {
    PHP_ME(Queue, push, arginfo_queue_push, ZEND_ACC_PUBLIC)
    PHP_ME(Queue, pop, arginfo_queue_pop, ZEND_ACC_PUBLIC)
    PHP_ME(Queue, front, arginfo_queue_front, ZEND_ACC_PUBLIC)
    PHP_FE_END
};

static zend_object_handlers queue_object_handlers;

static void queue_object_init(zend_class_entry *class_type)
{
    queue_object_handlers = 
        *zend_get_std_object_handlers();
    queue_object_handlers.offset = 
        XtOffsetOf(queue_object, std);
    queue_object_handlers.free_obj = 
        queue_object_free;
    queue_object_handlers.clone_obj = 
        zend_objects_clone_obj;
}

static zend_object *queue_object_new(zend_class_entry *class_type)
{
    queue_object *intern = 
        (queue_object *)ecalloc(1, sizeof(queue_object));
    zend_object_std_init(&intern->std, class_type);
    object_properties_init(&intern->std, class_type);
    intern->std.handlers = &queue_object_handlers;
    intern->q = 
        queue_new();
    return &intern->std;
}

static void queue_object_free(zend_object *object)
{
    queue_object *intern = 
        queue_object_from_obj(object);
    if (intern->q != NULL) {
        queue_free(intern->q);
    }
    zend_object_std_dtor(object);
}

PHP_MINIT_FUNCTION(queue)
{
    zend_class_entry ce;
    INIT_CLASS_ENTRY(ce, "Queue", queue_methods);
    queue_class_entry = zend_register_internal_class(&ce);
    queue_class_entry->create_object =
        queue_object_new;
    queue_object_init(
        queue_class_entry
    );
    return SUCCESS;
}

使用上述扩展，可以轻松地实现PHP中的队列数据结构，并提高PHP多线程任务的处理等应用场景的性能。

总结

经过上述的介绍，我们了解了PHP底层的高性能数据结构及其实现方法，并提供了相应的代码示例。通过使用扩展实现高性能数据结构，可以极大地提高PHP的性能，特别是在处理大量数据和多线程任务的情况下，更是可以显著地提升系统的性能。

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