Edit report at http://bugs.php.net/bug.php?id=53854&edit=1
ID: 53854
Updated by: rquadl...@php.net
Reported by: rquadl...@php.net
Summary: Missing constants for compression type.
Status: Assigned
Type: Bug
Package: Zip Related
Operating System: n/a
PHP Version: 5.3SVN-2011-01-27 (SVN)
Assigned To: aharvey
Block user comment: N
Private report: N
New Comment:
I've built a zip file containing the following compression methods (the
table below shows the value, the constant name and
ZipArchive::getStatusString()'s output when decompression is attempted
and fails) :
0 : CM_STORE : Decompression supported.
1 : CM_SHRINK : Compression method not supported.
6 : CM_IMPLODE : Compression method not supported.
8 : CM_DEFLATE : Decompression supported.
9 : CM_DEFLATE64 : Compression method not supported.
10 : CM_PKWARE_IMPLODE : Compression method not supported.
12 : CM_BZIP2 : Compression method not supported.
14 : CM_LZMA : Compression method not supported.
97 : CM_WAVPACK : Compression method not supported.
98 : CM_PPMD : Compression method not supported.
I cannot find any app that will create a ZIP file using the following
compression methods.
2 : CM_REDUCE_1
3 : CM_REDUCE_2
4 : CM_REDUCE_3
5 : CM_REDUCE_4
18 : CM_TERSE
19 : CM_LZ77
I have Terse (Hercules app) and LZ77 (I think this is the Microsoft
Compress format), but they do not create .ZIP files and the files
magic-bytes are not zip related - so you can't just call the file a .zip
file and get away with it.
I've got nowhere with REDUCE.
I've got a zip file and .phpt test to cover the compression methods I
have found.
Given what I've found so far, I'm guessing that php_zip only really
supports storing and deflating/inflating. The constants for the
compression methods that I've managed to test should be exposed.
Those that I've not should be removed be unexposed and removed from the
documentation.
But I'd like to add to the docs something along the lines of "Other
compression methods may exist."
Richard.
Previous Comments:
------------------------------------------------------------------------
[2011-01-28 12:27:04] paj...@php.net
Let try to keep this discussion sane...:
We can keep them only if it is supported at least to read the
information about
an entry. For example, if an entry uses LZ77, then doing a stat/reading
the info
MUST return CW_LZ77.
If that's not the case, then we must remove them as it makes no sense to
expose
them to the user.
Is it more clear now? :)
------------------------------------------------------------------------
[2011-01-28 12:11:02] rquadl...@php.net
Just as an aside, the error constants that ARE documented ... I can see
no way to
generate them. None of the methods or functions in php_zip return an
error
constant. Should these be removed?
------------------------------------------------------------------------
[2011-01-28 12:06:05] paj...@php.net
That's what I asked. We can keep them only and only if libzip detects
AND uses
these compression types correctly. It seems to be the case. Can you
confirm it and
maybe add a test per compression method?
------------------------------------------------------------------------
[2011-01-28 12:03:35] rquadl...@php.net
I took a file (an uncompressed WAV file) and compressed it using WinZip
V15 using different algorithms.
Using the following code ...
<?php
$zip = new ZipArchive;
$zip->open('wav.zipx');
foreach(range(0, $zip->numFiles - 1) as $index) {
print_r($stat = $zip->statIndex($index));
$zip->extractTo('.', array($stat['name']));
echo $zip->getStatusString(), PHP_EOL;
}
$zip->close();
Outputs ...
Array
(
[name] => WavPack.wav
[index] => 0
[crc] => 1384274557
[size] => 154826
[mtime] => 1296208410
[comp_size] => 45366
[comp_method] => 97
)
Compression method not supported
Array
(
[name] => PPMD.wav
[index] => 1
[crc] => 1384274557
[size] => 154826
[mtime] => 1296208410
[comp_size] => 100729
[comp_method] => 98
)
Compression method not supported
Array
(
[name] => LZMA.wav
[index] => 2
[crc] => 1384274557
[size] => 154826
[mtime] => 1296208410
[comp_size] => 68162
[comp_method] => 14
)
Compression method not supported
Array
(
[name] => BZIP2.wav
[index] => 3
[crc] => 1384274557
[size] => 154826
[mtime] => 1296208410
[comp_size] => 104633
[comp_method] => 12
)
Compression method not supported
As you can see, 98, 97, 14 and 12 are all identified as the comp_method
(correctly). None of these compression methods are supported by php_zip,
but the constants should be present to allow determination of the method
used.
Interestingly WavPack was the best algorithm to use on uncompressed
audio (which WinZip performed when I asked it to "compress to the
smallest size").
I can send the zip file if needed (300K).
I think it is important to remember that the zip files being accessed by
php_zip may not have been produced by php_zip.
------------------------------------------------------------------------
[2011-01-28 11:34:43] paj...@php.net
If they are not implemented, no, it does not make sense to have them
exposed. If
one uses them he will then expect the compression mode to be set and
used
accordingly.
However for reading archive and get information about a given
compression mode,
yes. But only if they are actually used and set by libzip. If not,
please revert
this change.
------------------------------------------------------------------------
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