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 The code to detect number of CPU cores doesn't count hyperthreading 16 as multiple cores. In context of xz, it probably should. 17 Hyperthreading is good at least with p7zip. 18 19 XZ Utils compress some files significantly worse than LZMA Utils. 20 This is due to faster compression presets used by XZ Utils, and 21 can often be worked around by using "xz --extreme". With some files 22 --extreme isn't enough though: it's most likely with files that 23 compress extremely well, so going from compression ratio of 0.003 24 to 0.004 means big relative increase in the compressed file size. 25 26 xz doesn't quote unprintable characters when it displays file names 27 given on the command line. 28 29 tuklib_exit() doesn't block signals => EINTR is possible. 30 31 SIGTSTP is not handled. If xz is stopped, the estimated remaining 32 time and calculated (de)compression speed won't make sense in the 33 progress indicator (xz --verbose). 34 35 36Missing features 37---------------- 38 39 xz doesn't support copying extended attributes, access control 40 lists etc. from source to target file. 41 42 Multithreaded compression 43 44 Multithreaded decompression 45 46 Buffer-to-buffer coding could use less RAM (especially when 47 decompressing LZMA1 or LZMA2). 48 49 I/O library is not implemented (similar to gzopen() in zlib). 50 It will be a separate library that supports uncompressed, .gz, 51 .bz2, .lzma, and .xz files. 52 53 lzma_strerror() to convert lzma_ret to human readable form? 54 This is tricky, because the same error codes are used with 55 slightly different meanings, and this cannot be fixed anymore. 56 57 58Documentation 59------------- 60 61 Some tutorial is needed for liblzma. I have planned to write some 62 extremely well commented example programs, which would work as 63 a tutorial. I suppose the Doxygen tags are quite OK as a quick 64 reference once one is familiar with the liblzma API. 65 66 Document the LZMA1 and LZMA2 algorithms. 67 68