diff --git a/Lib/gzip.py b/Lib/gzip.py index ddc7bda1fecbbd..e59b4548143272 100644 --- a/Lib/gzip.py +++ b/Lib/gzip.py @@ -17,6 +17,11 @@ READ, WRITE = 1, 2 +_COMPRESS_LEVEL_FAST = 1 +_COMPRESS_LEVEL_TRADEOFF = 6 +_COMPRESS_LEVEL_BEST = 9 + + def open(filename, mode="rb", compresslevel=9, encoding=None, errors=None, newline=None): """Open a gzip-compressed file in binary or text mode. @@ -191,7 +196,7 @@ def __init__(self, filename=None, mode=None, self.fileobj = fileobj if self.mode == WRITE: - self._write_gzip_header() + self._write_gzip_header(compresslevel) @property def filename(self): @@ -218,7 +223,7 @@ def _init_write(self, filename): self.bufsize = 0 self.offset = 0 # Current file offset for seek(), tell(), etc - def _write_gzip_header(self): + def _write_gzip_header(self, compresslevel): self.fileobj.write(b'\037\213') # magic header self.fileobj.write(b'\010') # compression method try: @@ -239,7 +244,13 @@ def _write_gzip_header(self): if mtime is None: mtime = time.time() write32u(self.fileobj, int(mtime)) - self.fileobj.write(b'\002') + if compresslevel == _COMPRESS_LEVEL_BEST: + xfl = b'\002' + elif compresslevel == _COMPRESS_LEVEL_FAST: + xfl = b'\004' + else: + xfl = b'\000' + self.fileobj.write(xfl) self.fileobj.write(b'\377') if fname: self.fileobj.write(fname + b'\000') diff --git a/Lib/test/test_gzip.py b/Lib/test/test_gzip.py index 17ecda2089f250..0251914d8bcaba 100644 --- a/Lib/test/test_gzip.py +++ b/Lib/test/test_gzip.py @@ -358,6 +358,26 @@ def test_metadata(self): isizeBytes = fRead.read(4) self.assertEqual(isizeBytes, struct.pack('