diff options
| -rw-r--r-- | zipstream.php | 222 |
1 files changed, 192 insertions, 30 deletions
diff --git a/zipstream.php b/zipstream.php index 1b38ad5..5b8965f 100644 --- a/zipstream.php +++ b/zipstream.php @@ -96,12 +96,42 @@ class ZipStream { # content_disposition - HTTP Content-Disposition. Defaults to # 'attachment; filename=\"FILENAME\"', where # FILENAME is the specified filename. + # large_file_size - Size, in bytes, of the largest file to try + # and load into memory (used by + # add_file_from_path()). Large files may also + # be compressed differently; see the + # 'large_file_method' option. + # large_file_method - How to handle large files. Legal values are + # 'store' (the default), or 'deflate'. Store + # sends the file raw and is significantly + # faster, while 'deflate' compresses the file + # and is much, much slower. Note that deflate + # must compress the file twice and extremely + # slow. # send_http_headers - Boolean indicating whether or not to send # the HTTP headers for this file. # # Note that content_type and content_disposition do nothing if you are # not sending HTTP headers. # + # Large File Support: + # + # By default, the method add_file_from_path() will send send files + # larger than 20 megabytes along raw rather than attempting to + # compress them. You can change both the maximum size and the + # compression behavior using the large_file_* options above, with the + # following caveats: + # + # * For "small" files (e.g. files smaller than large_file_size), the + # memory use can be up to twice that of the actual file. In other + # words, adding a 10 megabyte file to the archive could potentially + # occupty 20 megabytes of memory. + # + # * Enabling compression on large files (e.g. files larger than + # large_file_size) is extremely slow, because ZipStream has to pass + # over the large file once to calculate header information, and then + # again to compress and send the actual data. + # # Examples: # # # create a new zip file named 'foo.zip' @@ -122,6 +152,12 @@ class ZipStream { # save options $this->opt = $opt; + # set large file defaults: size = 20 megabytes, method = store + if (!$this->opt['large_file_size']) + $this->opt['large_file_size'] = 20 * 1024 * 1024; + if (!$this->opt['large_file_method']) + $this->opt['large_file_method'] = 'store'; + $this->output_name = $name; if ($name || $opt['send_http_headers']) $this->need_headers = true; @@ -163,35 +199,59 @@ class ZipStream { # calculate header attributes $crc = crc32($data); $zlen = strlen($zdata); - $nlen = strlen($name); $len = strlen($data); + $meth = 0x08; - # create dos timestamp - $opt['time'] = $opt['time'] ? $opt['time'] : time(); - $dts = $this->dostime($opt['time']); - - # build file header - $fields = array( # (from V.A of APPNOTE.TXT) - array('V', 0x04034b50), # local file header signature - array('v', 0x14), # version needed to extract - array('v', 0x00), # general purpose bit flag - array('v', 0x08), # compresion method (deflate) - array('V', $dts), # dos timestamp - array('V', $crc), # crc32 of data - array('V', $zlen), # compressed data length - array('V', $len), # uncompressed data length - array('v', $nlen), # filename length - array('v', 0), # extra data len - ); - - # pack fields - $ret = $this->pack_fields($fields) . $name . $zdata; - - # add to central directory record and increment offset - $this->add_to_cdr($name, $opt, $crc, $zlen, $len, strlen($ret)); + # send file header + $this->add_file_header($name, $opt, $meth, $crc, $zlen, $len); # print data - $this->send($ret); + $this->send($zdata); + } + + # + # add_file_from_path - add a file at path to the archive. + # + # Note that large files may be compresed differently than smaller + # files; see the "Large File Support" section above for more + # information. + # + # Parameters: + # + # $name - name of file in archive (including directory path). + # $path - path to file on disk. + # $opt - Hash of options for file (optional, see "File Options" + # below). + # + # File Options: + # time - Last-modified timestamp (seconds since the epoch) of + # this file. Defaults to the current time. + # comment - Comment related to this file. + # + # Examples: + # + # # add a file named 'foo.txt' from the local file '/tmp/foo.txt' + # $zip->add_file_from_path('foo.txt', '/tmp/foo.txt'); + # + # # add a file named 'bigfile.rar' from the local file + # # '/usr/share/bigfile.rar' with a comment and a last-modified + # # time of two hours ago + # $path = '/usr/share/bigfile.rar'; + # $zip->add_file_from_path('bigfile.rar', $path, array( + # 'time' => time() - 2 * 3600, + # 'comment' => 'this is a comment about bar.jpg', + # )); + # + function add_file_from_path($name, $path, $opt = array()) { + if ($this->is_large_file($path)) { + # file is too large to be read into memory; add progressively + $this->add_large_file($name, $path, $opt); + } else { + # file is small enough to read into memory; read file contents and + # handle with add_file() + $data = file_get_contents($path); + $this->add_file($name, $data, $opt); + } } # @@ -218,10 +278,112 @@ class ZipStream { ################### # + # Create and send zip header for this file. + # + function add_file_header($name, $opt, $meth, $crc, $zlen, $len) { + # calculate name length + $nlen = strlen($name); + + # create dos timestamp + $opt['time'] = $opt['time'] ? $opt['time'] : time(); + $dts = $this->dostime($opt['time']); + + # build file header + $fields = array( # (from V.A of APPNOTE.TXT) + array('V', 0x04034b50), # local file header signature + array('v', 0x14), # version needed to extract + array('v', 0x00), # general purpose bit flag + array('v', $meth), # compresion method (deflate or store) + array('V', $dts), # dos timestamp + array('V', $crc), # crc32 of data + array('V', $zlen), # compressed data length + array('V', $len), # uncompressed data length + array('v', $nlen), # filename length + array('v', 0), # extra data len + ); + + # pack fields and calculate "total" length + $ret = $this->pack_fields($fields); + $cdr_len = strlen($ret) + $nlen + $zlen; + + # print header and filename + $this->send($ret . $name); + + # add to central directory record and increment offset + $this->add_to_cdr($name, $opt, $meth, $crc, $zlen, $len, $cdr_len); + } + + # + # Add a large file from the given path. + # + function add_large_file($name, $path, $opt = array()) { + $st = stat($path); + $block_size = 1048576; # process in 1 megabyte chunks + + # calculate header attributes + $zlen = $len = $st['size']; + + $meth_str = $this->opt['large_file_method']; + if ($meth_str == 'store') { + # store method + $meth = 0x00; + $crc = hash_file('crc32', $path); + } elseif ($meth_str == 'deflate') { + # deflate method + $meth = 0x08; + + # open file, calculate crc and compressed file length + $fh = fopen($path, 'rb'); + $hash_ctx = hash_init('crc32'); + $zlen = 0; + + # read each block, update crc and zlen + while ($data = fgets($fh, $block_size)) { + hash_update($hash_ctx, $data); + $data = gzdeflate($data); + $zlen += strlen($data); + } + + # close file and finalize crc + fclose($fh); + $crc = hash_final($hash_ctx); + } else { + die("unknown large_file_method: $meth_str"); + } + + # send file header + $this->add_file_header($name, $opt, $meth, $crc, $zlen, $len); + + # open input file + $fh = fopen($path, 'rb'); + + # send file blocks + while ($data = fgets($fh, $block_size)) { + if ($meth_str == 'deflate') + $data = gzdeflate($data); + + # send data + $this->send($data); + } + + # close input file + fclose($fh); + } + + # + # Is this file larger than large_file_size? + # + function is_large_file($path) { + $st = stat($path); + return ($this->opt['large_file_size'] > 0) && + ($st['size'] > $this->opt['large_file_size']); + } + + # # Save file attributes for trailing CDR record. # - function add_to_cdr($name, $opt, $crc, $zlen, $len, $rec_len) { - $this->files[] = array($name, $opt, $crc, $zlen, $len, $this->ofs); + function add_to_cdr($name, $opt, $meth, $crc, $zlen, $len, $rec_len) { + $this->files[] = array($name, $opt, $meth, $crc, $zlen, $len, $this->ofs); $this->ofs += $rec_len; } @@ -229,7 +391,7 @@ class ZipStream { # Send CDR record for specified file. # function add_cdr_file($args) { - list ($name, $opt, $crc, $zlen, $len, $ofs) = $args; + list ($name, $opt, $meth, $crc, $zlen, $len, $ofs) = $args; # get attributes $comment = $opt['comment'] ? $opt['comment'] : ''; @@ -237,12 +399,12 @@ class ZipStream { # get dos timestamp $dts = $this->dostime($opt['time']); - $fields = array( # (from V,F of APPNOTE.TXT) + $fields = array( # (from V,F of APPNOTE.TXT) array('V', 0x02014b50), # central file header signature array('v', 0x00), # version made by array('v', 0x14), # version needed to extract array('v', 0x00), # general purpose bit flag - array('v', 0x08), # compresion method (deflate) + array('v', $meth), # compresion method (deflate or store) array('V', $dts), # dos timestamp array('V', $crc), # crc32 of data array('V', $zlen), # compressed data length |