php内置函数分析之array_column()

 1 PHP_FUNCTION(array_column) 2 { 3 ????zval *zcolumn = NULL, *zkey = NULL, *data; 4 ????HashTable *arr_hash; 5 ????zval *zcolval = NULL, *zkeyval = NULL, rvc, rvk; 6 ?7 ????// !如果接收了一个php语言里的null变量，则直接将其转成C语言里的NULL，而不是封装成IS_NULL类型的zval ?8 ????if (zend_parse_parameters(ZEND_NUM_ARGS(), "hz!|z!", &arr_hash, &zcolumn, &zkey) == FAILURE) { 9 ????????return;10 ????}11 12 ????/* 检查colunm和index是否有效（只能为数字和对象，对象需能转换为字符串）。13 ????* ?无效则报The %s key should be either a string or an integer的warning错误。14 ????*/15 ????if ((zcolumn && !array_column_param_helper(zcolumn, "column")) ||16 ????????(zkey && !array_column_param_helper(zkey, "index"))) {17 ????????RETURN_FALSE;18 ????}19 ????// 初始化返回值20 ????array_init(return_value);21 ????// 循环遍历数组22 ????ZEND_HASH_FOREACH_VAL(arr_hash, data) {23 ????????ZVAL_DEREF(data);24 25 ????????if (!zcolumn) { // column未设置26 ????????????zcolval = data;27 ????????} else if ((zcolval = array_column_fetch_prop(data, zcolumn, &rvc)) == NULL) {// 该列的值为NULL,则跳过，进入下一循环28 ????????????continue;29 ????????}30 31 ????????/* Failure will leave zkeyval alone which will land us on the final else block below32 ?????????* which is to append the value as next_index33 ?????????*/34 ????????if (zkey) {35 ????????????zkeyval = array_column_fetch_prop(data, zkey, &rvk); // 获取zkey对应的列，作为返回数组的键/索引36 ????????}37 38 ????????Z_TRY_ADDREF_P(zcolval);39 ????????// 返回值数组：array(zkeyval=>zcolval,...)40 ????????if (zkeyval && Z_TYPE_P(zkeyval) == IS_STRING) {41 ????????????zend_symtable_update(Z_ARRVAL_P(return_value), Z_STR_P(zkeyval), zcolval);42 ????????} else if (zkeyval && Z_TYPE_P(zkeyval) == IS_LONG) {43 ????????????add_index_zval(return_value, Z_LVAL_P(zkeyval), zcolval);44 ????????} else if (zkeyval && Z_TYPE_P(zkeyval) == IS_OBJECT) {45 ????????????zend_string *key = zval_get_string(zkeyval);46 ????????????zend_symtable_update(Z_ARRVAL_P(return_value), key, zcolval);47 ????????????zend_string_release(key);48 ????????} else {49 ????????????// 没有zkeyval，则返回值数组为索引数组50 ????????????add_next_index_zval(return_value, zcolval);51 ????????}52 ????????/* 清理内存 */53 ????????if (zcolval == &rvc) {54 ????????????zval_ptr_dtor(&rvc);55 ????????}56 ????????if (zkeyval == &rvk) {57 ????????????zval_ptr_dtor(&rvk);58 ????????}59 ????} ZEND_HASH_FOREACH_END();60 }