create / merge file chunks using php

file_chunks.php

<?php
/*****************************************
 * App		: create / merge file chunks using php
 * File		: file_chunks.php
 * Date		: Wed Nov 28 16:40:42 +03 2018
 * Version	: 1.0.0
 * Email	: yasinkarabulak@gmail.com
 * 
 * MIT License
 * Copyright (c) 2018 Yasin KARABULAK
*******************************************/

//~ Options
$fileName = "Sword Art Online_ Alicization.ep8.mp4";
$chunkSize = 2048 * 1024; //~ bytes
$chunkCount = getChunkCount( $fileName, $chunkSize );
$saveChunksAs = "_chunks/";
	!is_dir( $saveChunksAs )? mkdir( $saveChunksAs ): null;
$saveMergedAs = "merged_".$fileName;

function getChunkCount ( $file, $chunkSize )
{
	$bytes = filesize( $file );
	
	if( $chunkSize < $bytes )
	{
		$mod = $bytes % $chunkSize;
		$chunkCount = ( $bytes - $mod ) / $chunkSize;
		$chunkCount++;
		return $chunkCount;
	}

	return (int)1;
}
echo getChunkCount( $fileName, $chunkSize ) . " piece(s)\n";


//~ server side slice
function createChunks ( $file, $chunkSize, $saveChunksAs )
{
	$chunksCount = getChunkCount( $file, $chunkSize );
	$seek = 0;
	
	for ( $i = 1; $i <= $chunksCount; $i++)
	{
		$fh = fopen( $file, 'rb' );
		fseek( $fh, $seek );
		$chunk = fread( $fh, $chunkSize );
		fclose( $fh );
		$seek = $seek + $chunkSize;
		
		$writeChunk = fopen( $saveChunksAs.$i, 'ab' );
		$write = fwrite( $writeChunk, $chunk );
		fclose( $writeChunk );
	}
}
createChunks( $fileName, $chunkSize, $saveChunksAs );


//~ local side merge
function mergeChunks ( $saveChunksAs, $chunkCount, $chunkSize, $saveMergedAs )
{
	for ($i = 1; $i <= $chunkCount; $i++)
	{
		
		$fh = fopen( $saveChunksAs.$i, 'rb' );
		$buffer = fread( $fh, $chunkSize );
		fclose( $fh );

		$total = fopen( $saveMergedAs, 'ab' );
		$write = fwrite( $total, $buffer );
		fclose( $total );
	}
}
mergeChunks ( $saveChunksAs, $chunkCount, $chunkSize, $saveMergedAs );
?>