<?php

if(!function_exists("str_starts_with")) {
    function str_starts_with($haystack, $needle) {
        if(!is_string($needle)||!is_string($haystack)) {
            return false;
        }
        if(strlen($needle)<=0) {
            return true;
        }
        if(strlen($needle)>strlen($haystack)) {
            return false;
        }
        if(strncmp($needle, $haystack, strlen($needle))==0) {
            return true;
        }
        return false;
        //end of str_starts_with
    }
}

if(!function_exists("mb_str_pad")) {
    function mb_str_pad($str, $pad_len, $pad_str=" ", $dir=STR_PAD_RIGHT, $encoding=null) {
        $encoding=($encoding===null?mb_internal_encoding():$encoding);
        $padBefore=($dir===STR_PAD_BOTH||$dir===STR_PAD_LEFT);
        $padAfter=($dir===STR_PAD_BOTH||$dir===STR_PAD_RIGHT);
        $pad_len-=mb_strlen($str, $encoding);
        $targetLen=$padBefore&&$padAfter?$pad_len/2:$pad_len;
        $strToRepeatLen=mb_strlen($pad_str, $encoding);
        $repeatTimes=ceil($targetLen/$strToRepeatLen);
        $repeatedString=str_repeat($pad_str, max(0, $repeatTimes)); // safe if used with valid utf-8 strings
        $before=$padBefore?mb_substr($repeatedString, 0, floor($targetLen), $encoding):"";
        $after=$padAfter?mb_substr($repeatedString, 0, ceil($targetLen), $encoding):"";
        return $before.$str.$after;
        //end of mb_str_pad
    }
}

function getms() {
    list($u, $s)=explode(" ", microtime());
    return (string)round(((float)$u+(float)$s)*1000);
}

function query2param() {
    $qstr="";
    if(array_key_exists("QUERY_STRING", $_SERVER)) {
        $qstr=$_SERVER["QUERY_STRING"];
    } else {
        $qstr=file_get_contents("php://input");
    }
    if(gettype($qstr)!="string"||strlen($qstr)<=0) {
        return false;
    }
    $param=[];
    $qstr=explode("&", $qstr);
    for($a=0; $a<count($qstr); $a++) {
        $qstr[$a]=explode("=", $qstr[$a], 2);
        if(count($qstr[$a])<=1) {
            $param[$qstr[$a][0]]="";
            continue;
        }
        $param[$qstr[$a][0]]=rawurldecode($qstr[$a][1]);
    }
    return $param;
}

function file_put_contents_with_lock($filename, $data) {
    $handle=fopen($filename, "c+");
    if($handle===false) {
        trigger_error("file_put_contents_with_lock: failed to open file ".$filename, E_USER_WARNING);
        return false;
    }
    if(!flock($handle, LOCK_EX)) {
        trigger_error("file_put_contents_with_lock: failed to lock file ".$filename." after fopen(...)", E_USER_WARNING);
        fclose($handle);
        return false;
    }
    ftruncate($handle, 0);
    rewind($handle);
    $result=fwrite($handle, $data);
    if($result===false) {
        trigger_error("file_put_contents_with_lock: failed to write file content of ".$filename, E_USER_WARNING);
    } else {
        fflush($handle);
    }
    flock($handle, LOCK_UN);
    fclose($handle);
    return $result;
}

function file_get_contents_with_lock($filename) {
    if(!file_exists($filename) || !is_readable($filename)) {
        trigger_error("file_get_contents_with_lock: file ".$filename." not exists or is not readable", E_USER_WARNING);
        return false;
    }
    $handle=fopen($filename, "rb");
    if($handle===false) {
        trigger_error("file_get_contents_with_lock: failed to open file ".$filename, E_USER_WARNING);
        return false;
    }
    if(!flock($handle, LOCK_SH)) {
        trigger_error("file_get_contents_with_lock: failed to lock file ".$filename." after fopen(...)", E_USER_WARNING);
        fclose($handle);
        return false;
    }
    $fsize=filesize($filename);
    $data=false;
    if($fsize===false) {
        trigger_error("file_get_contents_with_lock: failed to get size of ".$filename, E_USER_WARNING);
    } else if($fsize==0) {
        $data="";
    } else {
        $data=fread($handle, $fsize);
    }
    flock($handle, LOCK_UN);
    fclose($handle);
    return $data;
}