package bz2

Exception IO_error is raised when there is an error reading or writing on a compressed channel ; the string argument is the message reported by the OS.

Exception Data_error is raised when a data integrity error is detected during decompression.

Exception Unexpected_EOF is raised when an in_channel finishes before the logical end of stream is detected.

Version of the underlying bzip2 library.

open_in ic opens a compressed stream reading from the Stdlib input channel ic.

• parameter small

  when true requests usage of a different method for decompressing that is slower but uses less memory. Defaults: false

read buf pos len reads up to len characters and store them in the string buffer buf, starting at position pos.

• returns

  number of bytes actually read, (a value strictly less than len means end of stream).

• raises End_of_file

  if end of stream was already reached.

If there's some data after the compressed stream that you want to read from the same Stdlib in_channel, use read_get_unused.

open_out oc creates an out_channel writing to the Stdlib output channel oc. Once the write operations are finished and the compressed channel is closed, it is possible to continue writing on the Stdlib channel. However, reading back requires special care (cf. above).

• parameter block

  block size to use for compresion. It is a value between 1 and 9 inclusive. 9 is the default and provides best compression but takes most memory.

write oc buf pos len writes len characters, coming from buf and starting at position pos, to oc

compress buf pos len compress a data chunk coming from buf, len character long, and starting at pos.

• returns

  compressed data chunk as string

uncompress buf pos len uncompress a data chunk comfing from buf, len character long, and starting at pos.

• parameter small

  see Bz2.open_in above

• returns

  uncompressed data chunk as string