xref: /freebsd/contrib/xz/TODO (revision 7431dfd4580e850375fe5478d92ec770344db098)
1
2XZ Utils To-Do List
3===================
4
5Known bugs
6----------
7
8    The test suite is too incomplete.
9
10    If the memory usage limit is less than about 13 MiB, xz is unable to
11    automatically scale down the compression settings enough even though
12    it would be  possible by switching from BT2/BT3/BT4 match finder to
13    HC3/HC4.
14
15    XZ Utils compress some files significantly worse than LZMA Utils.
16    This is due to faster compression presets used by XZ Utils, and
17    can often be worked around by using "xz --extreme". With some files
18    --extreme isn't enough though: it's most likely with files that
19    compress extremely well, so going from compression ratio of 0.003
20    to 0.004 means big relative increase in the compressed file size.
21
22    xz doesn't quote unprintable characters when it displays file names
23    given on the command line.
24
25    tuklib_exit() doesn't block signals => EINTR is possible.
26
27    SIGTSTP is not handled. If xz is stopped, the estimated remaining
28    time and calculated (de)compression speed won't make sense in the
29    progress indicator (xz --verbose).
30
31
32Missing features
33----------------
34
35    xz doesn't support copying extended attributes, access control
36    lists etc. from source to target file.
37
38    Multithreaded compression
39
40    Multithreaded decompression
41
42    Buffer-to-buffer coding could use less RAM (especially when
43    decompressing LZMA1 or LZMA2).
44
45    I/O library is not implemented (similar to gzopen() in zlib).
46    It will be a separate library that supports uncompressed, .gz,
47    .bz2, .lzma, and .xz files.
48
49    lzma_strerror() to convert lzma_ret to human readable form?
50    This is tricky, because the same error codes are used with
51    slightly different meanings, and this cannot be fixed anymore.
52
53
54Documentation
55-------------
56
57    Some tutorial is needed for liblzma. I have planned to write some
58    extremely well commented example programs, which would work as
59    a tutorial. I suppose the Doxygen tags are quite OK as a quick
60    reference once one is familiar with the liblzma API.
61
62    Document the LZMA1 and LZMA2 algorithms.
63
64