diff options
Diffstat (limited to 'dedup')
| -rw-r--r-- | dedup/compression.py | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/dedup/compression.py b/dedup/compression.py index 52917e3..5df6613 100644 --- a/dedup/compression.py +++ b/dedup/compression.py @@ -1,7 +1,10 @@ +import bz2 import struct import sys import zlib +import lzma + crc32_type = "L" if sys.version_info.major >= 3 else "l" class GzipDecompressor(object): @@ -151,3 +154,32 @@ class DecompressedStream(object): self.decompressor = None self.buff = b"" self.closed = True + +decompressors = { + '.gz': GzipDecompressor, + '.bz2': bz2.BZ2Decompressor, + '.lzma': lzma.LZMADecompressor, + '.xz': lzma.LZMADecompressor, +} + +def decompress(filelike, extension): + """Decompress a stream according to its extension. + @param filelike: is a read-only byte-stream. It must support read(size) and + close(). + @param extension: permitted values are "", ".gz", ".bz2", ".lzma", and + ".xz" + @type extension: str + @returns: a read-only byte-stream with the decompressed contents of the + original filelike. It supports read(size) and close(). If the + original supports seek(pos) and tell(), then it also supports + those. + @raises ValueError: on unkown extensions + """ + if not extension: + return filelike + try: + decompressor = decompressors[extension] + except KeyError: + raise ValueError("unknown compression format with extension %r" % + extension) + return DecompressedStream(filelike, decompressor()) |