PHP 拡張機能開発ノート (5) 配列操作に関連するいくつかのマクロと簡単な例

同様の isset($array[$value]) 関数を実装するには、PHP コードは次のとおりです

<code><span><?php</span><span><span>class</span><span>Slash_Log</span> {</span><span>protected</span><span>static</span><span>$levels</span> = <span>array</span>(
        <span>1</span> => <span>"ERROR"</span>,
        <span>2</span> => <span>"WARNING"</span>,
        <span>3</span> => <span>"INFO"</span>,
        <span>4</span> => <span>"DEBUG"</span>,
    );

    <span>public</span><span><span>function</span><span>setLevel</span><span>(<span>$level</span>)</span> {</span><span>if</span> (!<span>isset</span>(<span>self</span>::<span>$levels</span>)) {
            <span>throw</span><span>new</span><span>Exception</span>(<span>"Level is not allowed"</span>);
        }
    }
}</span></code>

C コードは次のとおりです

<code>PHP_METHOD(slash_log, setLevel) {

    <span>long</span> level;
    zval *levels;
    zend_class_entry *ce;
    HashTable *levels_ht;

    ce = Z_OBJCE_P(getThis());
    <span>if</span> (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, <span>"l"</span>, &level) == FAILURE)
    {
        php_error_docref(NULL TSRMLS_CC, E_WARNING, <span>"Invalid argument"</span>);
        RETURN_FALSE;
    }

    levels = zend_read_static_property(ce, ZEND_STRL(SL_P_LEVELS), <span>0</span> TSRMLS_DC);
    levels_ht = Z_ARRVAL_P(levels);

    <span>if</span> (!zend_hash_index_exists(levels_ht, level)) {
        php_error_docref(NULL TSRMLS_CC, E_WARNING, <span>"Level is not allowed"</span>);
        RETURN_FALSE;
    }

    zend_update_property_long(ce, getThis(), ZEND_STRL(SL_P_LEVEL), level TSRMLS_CC);
    RETURN_TRUE;
}</code>

上記の例では、主に zend_hash_index_exists メソッドが使用されています Zend/ にはハッシュ テーブルを操作するための一連のメソッドがあります。 zend_hash.h

<code>ZEND_API <span>int</span> zend_hash_add_empty_element(HashTable *ht, <span>const</span><span>char</span> *arKey, uint nKeyLength);
ZEND_API <span>int</span> zend_hash_del_key_or_index(HashTable *ht, <span>const</span><span>char</span> *arKey, uint nKeyLength, ulong h, <span>int</span> flag);
ZEND_API <span>int</span> zend_hash_find(<span>const</span> HashTable *ht, <span>const</span><span>char</span> *arKey, uint nKeyLength, <span>void</span> **pData);
ZEND_API <span>int</span> zend_hash_quick_find(<span>const</span> HashTable *ht, <span>const</span><span>char</span> *arKey, uint nKeyLength, ulong h, <span>void</span> **pData);
ZEND_API <span>int</span> zend_hash_index_find(<span>const</span> HashTable *ht, ulong h, <span>void</span> **pData);
ZEND_API <span>int</span> zend_hash_exists(<span>const</span> HashTable *ht, <span>const</span><span>char</span> *arKey, uint nKeyLength);
ZEND_API <span>int</span> zend_hash_quick_exists(<span>const</span> HashTable *ht, <span>const</span><span>char</span> *arKey, uint nKeyLength, ulong h);
ZEND_API <span>int</span> zend_hash_index_exists(<span>const</span> HashTable *ht, ulong h);
ZEND_API <span>int</span> zend_hash_move_forward_ex(HashTable *ht, HashPosition *pos);
ZEND_API <span>int</span> zend_hash_move_backwards_ex(HashTable *ht, HashPosition *pos);
ZEND_API <span>int</span> zend_hash_get_current_key_ex(<span>const</span> HashTable *ht, <span>char</span> **str_index, uint *str_length, ulong *num_index, zend_bool duplicate, HashPosition *pos);
ZEND_API <span>int</span> zend_hash_get_current_key_type_ex(HashTable *ht, HashPosition *pos);
ZEND_API <span>int</span> zend_hash_get_current_data_ex(HashTable *ht, <span>void</span> **pData, HashPosition *pos);
ZEND_API <span>int</span> zend_hash_update_current_key_ex(HashTable *ht, <span>int</span> key_type, <span>const</span><span>char</span> *str_index, uint str_length, ulong num_index, <span>int</span> mode, HashPosition *pos);
ZEND_API <span>int</span> zend_hash_get_pointer(<span>const</span> HashTable *ht, HashPointer *ptr);
ZEND_API <span>int</span> zend_hash_set_pointer(HashTable *ht, <span>const</span> HashPointer *ptr);
ZEND_API <span>int</span> zend_hash_sort(HashTable *ht, sort_func_t sort_func, compare_func_t compare_func, <span>int</span> renumber TSRMLS_DC);
ZEND_API <span>int</span> zend_hash_compare(HashTable *ht1, HashTable *ht2, compare_func_t compar, zend_bool ordered TSRMLS_DC);
ZEND_API <span>int</span> zend_hash_minmax(<span>const</span> HashTable *ht, compare_func_t compar, <span>int</span> flag, <span>void</span> **pData TSRMLS_DC);
ZEND_API <span>int</span> zend_hash_num_elements(<span>const</span> HashTable *ht);
ZEND_API <span>int</span> zend_hash_rehash(HashTable *ht);</code>

上記では、PHP 拡張機能の開発ノート (5) に関連する内容を含むいくつかのマクロと簡単な例を紹介しています。PHP チュートリアルに興味のある友人に役立つことを願っています。