使用php加速递归foreach

Question

I am running this against an associative (non-numerical keys) array that is 80K lines, decoded from a 2.1K json file:

$ret = array();

function recursive(array $array, $tableName, $level=''){

global $ret;

$tableData = array();

    foreach($array as $key => $value){
        if(!is_array($key)) $k = $key;  // keep array keys for tablename

        if(is_array($value)){
            $key = is_int($key) ? $tableName : $key; //skip empty subarrays
            recursive($value, $level=$key);

        } else{
            $tableData=[$tableName, $k, $value];
        }
        if (!empty($tableData))
        {array_push($ret, $tableData);
        }

    }
 return $ret;
}

$ret =(recursive($array, 'project'));

The json data contains empty sub-arrays which are discarded during the 'is_int($key) recursive loop. This is a typical file size that will be processed and the function is taking over 2 mins to run - which may be as good as it gets - but I wanted to ask if there were any ways to speed this function up by better coding.

thank you,

Answer 1

It seems to be always true: if(!is_array($key)) $k = $key;

You are don't use the $level variable. Why do you need it?

Globals are really bad idea. You probably need to send variables to your function by link instead of value:

function recursive(&$data, &$result, $tableName)
{
    //some of your logic here
    //...
    //if you need a recursion call
    recursive($data, $result, $tableName);
}

//function call
$result = [];
recoursive($data, $result, 'project');

//all of your data now in the result variable

Also it may be a good idea to read and process your data by chunks. Iterators or generators can help you with this.