MainLoggerThread.php

<?php
 
/*
 *
 *  ____            _        _   __  __ _                  __  __ ____
 * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
 * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
 * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
 * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * @author PocketMine Team
 * @link http://www.pocketmine.net/
 *
 *
 */
 
declare(strict_types=1);
 
namespace pocketmine\utils;
 
use pmmp\thread\Thread;
use pmmp\thread\ThreadSafeArray;
use function clearstatcache;
use function date;
use function fclose;
use function file_exists;
use function fopen;
use function fstat;
use function fwrite;
use function is_dir;
use function is_file;
use function is_resource;
use function mkdir;
use function pathinfo;
use function rename;
use function strlen;
use function touch;
use const PATHINFO_EXTENSION;
use const PATHINFO_FILENAME;
 
final class MainLoggerThread extends Thread{
 
    private ThreadSafeArray $buffer;
    private bool $syncFlush = false;
    private bool $shutdown = false;
 
    public function __construct(
        private string $logFile,
        private ?string $archiveDir,
        private readonly int $maxFileSize = 32 * 1024 * 1024 //32 MB
    ){
        $this->buffer = new ThreadSafeArray();
        touch($this->logFile);
        if($this->archiveDir !== null && !@mkdir($this->archiveDir) && !is_dir($this->archiveDir)){
            throw new \RuntimeException("Unable to create archive directory: " . (
                is_file($this->archiveDir) ? "it already exists and is not a directory" : "permission denied"));
        }
    }
 
    public function write(string $line) : void{
        $this->synchronized(function() use ($line) : void{
            $this->buffer[] = $line;
            $this->notify();
        });
    }
 
    public function syncFlushBuffer() : void{
        $this->synchronized(function() : void{
            $this->syncFlush = true;
            $this->notify(); //write immediately
        });
        $this->synchronized(function() : void{
            while($this->syncFlush){
                $this->wait(); //block until it's all been written to disk
            }
        });
    }
 
    public function shutdown() : void{
        $this->synchronized(function() : void{
            $this->shutdown = true;
            $this->notify();
        });
        $this->join();
    }
 
    private function openLogFile(string $file, int &$size){
        $logResource = fopen($file, "ab");
        if(!is_resource($logResource)){
            throw new \RuntimeException("Couldn't open log file");
        }
        $stat = fstat($logResource);
        if($stat === false){
            throw new AssumptionFailedError("fstat() should not fail here");
        }
        $size = $stat['size'];
        return $logResource;
    }
 
    private function archiveLogFile($logResource, int &$size, string $archiveDir){
        fclose($logResource);
 
        clearstatcache();
 
        $i = 0;
        $date = date("Y-m-d\TH.i.s");
        $baseName = pathinfo($this->logFile, PATHINFO_FILENAME);
        $extension = pathinfo($this->logFile, PATHINFO_EXTENSION);
        do{
            //this shouldn't be necessary, but in case the user messes with the system time for some reason ...
            $fileName = "$baseName.$date.$i.$extension";
            $out = $this->archiveDir . "/" . $fileName;
            $i++;
        }while(file_exists($out));
 
        //the user may have externally deleted the whole directory - make sure it exists before we do anything
        @mkdir($archiveDir);
        rename($this->logFile, $out);
 
        $logResource = $this->openLogFile($this->logFile, $size);
        fwrite($logResource, "--- Starting new log file - old log file archived as $fileName ---\n");
 
        return $logResource;
    }
 
    private function logFileReadyToArchive(int $size) : bool{
        return $size >= $this->maxFileSize;
    }
 
    private function writeLogStream(&$logResource, int &$size, ?string $archiveDir) : void{
        while(($chunk = $this->buffer->shift()) !== null){
            fwrite($logResource, $chunk);
            $size += strlen($chunk);
            if($archiveDir !== null && $this->logFileReadyToArchive($size)){
                $logResource = $this->archiveLogFile($logResource, $size, $archiveDir);
            }
        }
 
        $this->synchronized(function() : void{
            if($this->syncFlush){
                $this->syncFlush = false;
                $this->notify(); //if this was due to a sync flush, tell the caller to stop waiting
            }
        });
    }
 
    public function run() : void{
        $size = 0;
        $logResource = $this->openLogFile($this->logFile, $size);
        $archiveDir = $this->archiveDir;
        if($archiveDir !== null && $this->logFileReadyToArchive($size)){
            $logResource = $this->archiveLogFile($logResource, $size, $archiveDir);
        }
 
        while(!$this->shutdown){
            $this->writeLogStream($logResource, $size, $archiveDir);
            $this->synchronized(function() : void{
                if(!$this->shutdown && !$this->syncFlush){
                    $this->wait();
                }
            });
        }
 
        $this->writeLogStream($logResource, $size, $archiveDir);
 
        fclose($logResource);
    }
}