giuseppe-rubino / threadzip Goto Github PK

Firstly, it takes quite a time to build threadzip on a system. This seems to be 
not a drop-in utility.

Secondly, but most importantly, threadzip MUST BE BACKWARDS COMPATIBLE to the 
traditional LZMA and its utilities: unlzma, lzcat, ... I believe this must the 
task #1 with highest priority on the threadzip's To-Do list.

Until the latter is done, sadly, we can't use this tool into production :(

python-2.6 provides a way to easily get the number of active cpus.  would be 
nice if threadzip/unzip defaulted to a better count than just "2".  patch 
attached to do just that.

What steps will reproduce the problem?

>>> import pylzma
>>> f = file('threadzip.py', 'r')
>>> data = f.read()
>>> f.close()
>>> enc = pylzma.compress(data)
>>> out = file('output.pylzma', 'w')
>>> out.write(enc)
>>> out.close()

$ ./threadzip.py -t 1 --lzma < threadzip.py > output.tz
$ dd if=output.tz skip=14 bs=1 > output_stripped.tz

Now hexdump output.pylzma and output_stripped.tz. The TZ version has extra 
bytes at the end. Otherwise, the buffers are identical.

What is the expected output? What do you see instead?
I thought they would match.

What version of the product are you using? On what operating system?
1.2 on OSX 10.8.2

Please provide any additional information below.
I was trying to see if pylzma produced output that could be verified with xz, 
so I'd know whether to blame threadzip or not. It doesn't, btw. I haven't tried 
to open the pylzma file with anything else, though.

What steps will reproduce the problem?
1. Many unzip programs will not open or unzip archives created with threadzip
2. Using the 'file' command in Linux identifies archives created with threadzip 
as generic 'data' files rather than BZ2 or LZMA compressed data files.

What is the expected output? What do you see instead?
The threadzip default output file does not seem to have a proper header 
identifying it, so only threadunzip or using a raw zlib/lzma/bzip2 decompressor 
will work.  Other programs, like 7Zip or various graphical clients, do not 
identify files created with threadzip as compressed archives and as such they 
won't open or unzip them.  Proper headers would greatly extend the usefulness 
of threadzip-created archives.

What version of the product are you using? On what operating system?
threadzip.py version 1.2, Linux (kernel 2.6.33)

Please provide any additional information below.