PHP oversized File Downloader [HTTP cache negotiation, ETag tagging, breakpoint continuation]_php Tutorial

002 $file _path = './download/download_cn.rar ';

003

004//How to use

005 Downfile ($file _path);

006

007//server file path, download file name (default is server file name), whether to license user download method (default), speed limit (default automatic), file type (default all)

008 function Downfile ($fileName, $fancyName = ', $forceDownload = true, $speedLimit = 0, $contentType = ') {

009 if (!is_readable ($fileName))

010 {

011 header ("http/1.1 404 Not Found");

012 return false;

013}

014

015 $fileStat = stat ($fileName);

016 $lastModified = $fileStat [' Mtime '];

017

018 $MD 5 = MD5 ($fileStat [' Mtime ']. ='. $fileStat [' ino ']. ' ='. $fileStat [' size ']);

019 $etag = ' "'. $MD 5. '-' . CRC32 ($MD 5). '"';

020

021 Header (' last-modified: '. Gmdate ("D, D M Y h:i:s", $lastModified). ' GMT ');

022 Header ("ETag: $etag");

023

024 if (isset ($_server[' http_if_modified_since ") && strtotime ($_server[' http_if_modified_since ']) >= $ LastModified)

025 {

026 header ("http/1.1 304 not Modified");

027 return true;

028}

12X

030 if (isset ($_server[' http_if_unmodified_since ') && strtotime ($_server[' http_if_unmodified_since ']) < $lastModified)

031 {

032 Header ("http/1.1 304 not Modified");

033 return true;

034}

035

036 if (isset ($_server[' Http_if_none_match ") && $_server[' http_if_none_match '] = = $etag)

037 {

038 Header ("http/1.1 304 not Modified");

039 return true;

040}

041

042 if ($fancyName = = ")

043 {

044 $fancyName = basename ($fileName);

045}

046

047 if ($contentType = = ")

048 {

049 $contentType = ' Application/octet-stream ';

050}

051

052 $fileSize = $fileStat [' Size '];

053

054 $contentLength = $fileSize;

055 $isPartial = false;

15W

057 if (isset ($_server[' Http_range '))

058 {

059 if (Preg_match ('/^bytes= (d*)-(d*) $/', $_server[' Http_range '], $matches))

060 {

061 $startPos = $matches [1];

062 $endPos = $matches [2];

063

064 if ($startPos = = "&& $endPos = =")

065 {

066 return false;

067}

068

069 if ($startPos = = ")

070 {

071 $startPos = $fileSize-$endPos;

072 $endPos = $fileSize-1;

073}

074 else if ($endPos = = ")

075 {

076 $endPos = $fileSize-1;

077}

078

079 $startPos = $startPos < 0? 0: $startPos;

080 $endPos = $endPos > $fileSize-1? $fileSize-1: $endPos;

081

082 $length = $endPos-$startPos + 1;

083

084 if ($length < 0)

085 {

086 return false;

087}

088

089 $contentLength = $length;

090 $isPartial = true;

091}

092}

093

094//Send headers

095 if ($isPartial)

096 {

097 header (' http/1.1 206 Partial Content ');

098 header ("Content-range:bytes $startPos-$endPos/$fileSize");

099

100}

101 Else

102 {

103 header ("http/1.1 OK");

104 $startPos = 0;

$endPos = $contentLength-1;

106}

107

108 header (' Pragma:cache ');

109 Header (' Cache-control:public, must-revalidate, max-age=0 ');

The header (' accept-ranges:bytes ');

111 Header (' Content-type: '. $contentType);

The header (' Content-length: '. $contentLength);

113

if ($forceDownload)

115 {

The header (' content-disposition:attachment; Filename= '. Rawurlencode ($fancyName). '"');

117}

118

119 Header ("Content-transfer-encoding:binary");

120

121 $bufferSize = 2048;

122

123 if ($speedLimit! = 0)

124 {

$packetTime = Floor ($bufferSize * 1000000/$speedLimit);

126}

127

$bytesSent = 0;

129 $fp = fopen ($fileName, "RB");

Fseek ($fp, $startPos);

131 while ($bytesSent < $contentLength &&!feof ($fp) && connection_status () = = 0)

132 {

133 if ($speedLimit! = 0)

134 {

135 list ($usec, $sec) = Explode ("", Microtime ());

136 $outputTimeStart = ((float) $usec + (float) $sec);

137}

138

139 $readBufferSize = $contentLength-$bytesSent < $bufferSize? $contentLength-$bytesSent: $bufferSize;

$buffer = Fread ($fp, $readBufferSize);

141

142 echo $buffer;

143

144 Ob_flush ();

145 flush ();

146

147 $bytesSent + = $readBufferSize;

148

149 if ($speedLimit! = 0)

150 {

151 list ($usec, $sec) = Explode ("", Microtime ());

$outputTimeEnd = ((float) $usec + (float) $sec);

153

154 $useTime = ((float) $outputTimeEnd-(float) $outputTimeStart) * 1000000;

155 $sleepTime = Round ($packetTime-$useTime);

156 if ($sleepTime > 0)

157 {

158 usleep ($sleepTime);

159}

160}

161}

162 return true;

163}

164?>

http://www.bkjia.com/PHPjc/444967.html www.bkjia.com true http://www.bkjia.com/PHPjc/444967.html techarticle PHP Tutorial 002 $file _path = './download/download_cn.rar '; 003 004//Method of Use 005 downfile ($file _path); 006 007//server file path, download file First name (default is server text ...)

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