PHP extension development notes (3) Static array attribute definition of class

php sample code

<code><span><span>class</span><span>Slash_Log</span> {</span><span>const</span> EMERGENCY = <span>1</span>;
    <span>const</span> ALERT = <span>2</span>;
    <span>const</span> CRITICAL = <span>3</span>;
    <span>const</span> FATAL = <span>3</span>;
    <span>const</span> ERROR = <span>4</span>;
    <span>const</span> WARN = <span>5</span>;
    <span>const</span> NOTICE = <span>6</span>;
    <span>const</span> INFO = <span>7</span>;
    <span>const</span> DEBUG = <span>8</span>;

    <span>public</span><span>static</span><span>$levels</span> = <span>array</span>(
        <span>self</span>::EMERGENCY => <span>1</span>,
        <span>self</span>::ALERT => <span>2</span>,
        <span>self</span>::CRITICAL => <span>3</span>,
        <span>self</span>::FATAL => <span>3</span>,
        <span>self</span>::ERROR => <span>4</span>,
        <span>self</span>::WARN => <span>5</span>,
        <span>self</span>::NOTICE => <span>6</span>,
        <span>self</span>::INFO => <span>7</span>,
        <span>self</span>::DEBUG => <span>8</span>,
   );
}</code>

Code implemented through php extension

<code>zend_class_entry ce;
SLASH_INIT_CLASS_ENTRY(ce, SLASH_CN_LOG, slash_log_methods);
slash_log_ce = zend_register_internal_class(&ce TSRMLS_CC);

<span>// {{{ log level</span>
zend_declare_class_constant_long(slash_log_ce, ZEND_STRL(SL_EMERGENCY_K), SL_EMERGENCY_V TSRMLS_CC);
zend_declare_class_constant_long(slash_log_ce, ZEND_STRL(SL_ALERT_K), SL_ALERT_V TSRMLS_CC);
zend_declare_class_constant_long(slash_log_ce, ZEND_STRL(SL_CRITICAL_K), SL_CRITICAL_V TSRMLS_CC);
zend_declare_class_constant_long(slash_log_ce, ZEND_STRL(SL_ERROR_K), SL_ERROR_V TSRMLS_CC);
zend_declare_class_constant_long(slash_log_ce, ZEND_STRL(SL_WARN_K), SL_WARN_V TSRMLS_CC);
zend_declare_class_constant_long(slash_log_ce, ZEND_STRL(SL_NOTICE_K), SL_NOTICE_V TSRMLS_CC);
zend_declare_class_constant_long(slash_log_ce, ZEND_STRL(SL_INFO_K), SL_INFO_V TSRMLS_CC);
zend_declare_class_constant_long(slash_log_ce, ZEND_STRL(SL_DEBUG_K), SL_DEBUG_V TSRMLS_CC);
<span>// }}}</span><span>// {{{ static property array</span>
zend_declare_property_null(slash_log_ce, ZEND_STRL(SL_P_LEVELS), ZEND_ACC_PUBLIC|ZEND_ACC_STATIC TSRMLS_CC);

zval *levels;
MAKE_STD_ZVAL(levels);
array_init(levels);

add_index_stringl(levels, SL_EMERGENCY_V, ZEND_STRL(SL_EMERGENCY_K), <span>0</span>);
add_index_stringl(levels, SL_ALERT_V, ZEND_STRL(SL_ALERT_K), <span>0</span>);
add_index_stringl(levels, SL_CRITICAL_V, ZEND_STRL(SL_CRITICAL_K), <span>0</span>);
add_index_stringl(levels, SL_ERROR_V, ZEND_STRL(SL_ERROR_K), <span>0</span>);
add_index_stringl(levels, SL_WARN_V, ZEND_STRL(SL_WARN_K), <span>0</span>);
add_index_stringl(levels, SL_NOTICE_V, ZEND_STRL(SL_NOTICE_K), <span>0</span>);
add_index_stringl(levels, SL_INFO_V, ZEND_STRL(SL_INFO_K), <span>0</span>);
add_index_stringl(levels, SL_DEBUG_V, ZEND_STRL(SL_DEBUG_K), <span>0</span>);
zend_update_static_property(slash_log_ce, ZEND_STRL(SL_P_LEVELS), levels TSRMLS_CC);
<span>// }}}</span></code>

Attention issues

As mentioned in note (1), extensions cannot directly initialize array attributes, so here we define a static attribute initialization is null (zend_declare_property_null), and then modify (zend_update_static_property) the value of this property to the corresponding array, thus achieving the effect of public static $array.

The corresponding variable name has a macro defined, so if you copy the code directly, it will not be compiled. Welcome to communicate

The above introduces the static array attribute definition of the PHP extension development notes (3) class, including the relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.