diff options
Diffstat (limited to 'Lib/gzip.py')
| -rw-r--r-- | Lib/gzip.py | 406 |
1 files changed, 203 insertions, 203 deletions
diff --git a/Lib/gzip.py b/Lib/gzip.py index 3d656b9..9c5ff0c 100644 --- a/Lib/gzip.py +++ b/Lib/gzip.py @@ -47,222 +47,222 @@ class GzipFile: myfileobj = None def __init__(self, filename=None, mode=None, - compresslevel=9, fileobj=None): - if fileobj is None: - fileobj = self.myfileobj = __builtin__.open(filename, mode or 'r') + compresslevel=9, fileobj=None): + if fileobj is None: + fileobj = self.myfileobj = __builtin__.open(filename, mode or 'r') if filename is None: - if hasattr(fileobj, 'name'): filename = fileobj.name - else: filename = '' + if hasattr(fileobj, 'name'): filename = fileobj.name + else: filename = '' if mode is None: - if hasattr(fileobj, 'mode'): mode = fileobj.mode - else: mode = 'r' - - if mode[0:1] == 'r': - self.mode = READ - self._init_read() - self.filename = filename - self.decompress = zlib.decompressobj(-zlib.MAX_WBITS) - - elif mode[0:1] == 'w': - self.mode = WRITE - self._init_write(filename) - self.compress = zlib.compressobj(compresslevel, - zlib.DEFLATED, - -zlib.MAX_WBITS, - zlib.DEF_MEM_LEVEL, - 0) - else: - raise ValueError, "Mode " + mode + " not supported" - - self.fileobj = fileobj - - if self.mode == WRITE: - self._write_gzip_header() - elif self.mode == READ: - self._read_gzip_header() + if hasattr(fileobj, 'mode'): mode = fileobj.mode + else: mode = 'r' + + if mode[0:1] == 'r': + self.mode = READ + self._init_read() + self.filename = filename + self.decompress = zlib.decompressobj(-zlib.MAX_WBITS) + + elif mode[0:1] == 'w': + self.mode = WRITE + self._init_write(filename) + self.compress = zlib.compressobj(compresslevel, + zlib.DEFLATED, + -zlib.MAX_WBITS, + zlib.DEF_MEM_LEVEL, + 0) + else: + raise ValueError, "Mode " + mode + " not supported" + + self.fileobj = fileobj + + if self.mode == WRITE: + self._write_gzip_header() + elif self.mode == READ: + self._read_gzip_header() def __repr__(self): - s = repr(self.fileobj) - return '<gzip ' + s[1:-1] + ' ' + hex(id(self)) + '>' + s = repr(self.fileobj) + return '<gzip ' + s[1:-1] + ' ' + hex(id(self)) + '>' def _init_write(self, filename): - if filename[-3:] != '.gz': - filename = filename + '.gz' - self.filename = filename - self.crc = zlib.crc32("") - self.size = 0 - self.writebuf = [] - self.bufsize = 0 + if filename[-3:] != '.gz': + filename = filename + '.gz' + self.filename = filename + self.crc = zlib.crc32("") + self.size = 0 + self.writebuf = [] + self.bufsize = 0 def _write_gzip_header(self): - self.fileobj.write('\037\213') # magic header - self.fileobj.write('\010') # compression method - fname = self.filename[:-3] - flags = 0 - if fname: - flags = FNAME - self.fileobj.write(chr(flags)) - write32(self.fileobj, int(time.time())) - self.fileobj.write('\002') - self.fileobj.write('\377') - if fname: - self.fileobj.write(fname + '\000') + self.fileobj.write('\037\213') # magic header + self.fileobj.write('\010') # compression method + fname = self.filename[:-3] + flags = 0 + if fname: + flags = FNAME + self.fileobj.write(chr(flags)) + write32(self.fileobj, int(time.time())) + self.fileobj.write('\002') + self.fileobj.write('\377') + if fname: + self.fileobj.write(fname + '\000') def _init_read(self): - self.crc = zlib.crc32("") - self.size = 0 - self.extrabuf = "" - self.extrasize = 0 + self.crc = zlib.crc32("") + self.size = 0 + self.extrabuf = "" + self.extrasize = 0 def _read_gzip_header(self): - magic = self.fileobj.read(2) - if magic != '\037\213': - raise RuntimeError, 'Not a gzipped file' - method = ord( self.fileobj.read(1) ) - if method != 8: - raise RuntimeError, 'Unknown compression method' - flag = ord( self.fileobj.read(1) ) - # modtime = self.fileobj.read(4) - # extraflag = self.fileobj.read(1) - # os = self.fileobj.read(1) - self.fileobj.read(6) - - if flag & FEXTRA: - # Read & discard the extra field, if present - xlen=ord(self.fileobj.read(1)) - xlen=xlen+256*ord(self.fileobj.read(1)) - self.fileobj.read(xlen) - if flag & FNAME: - # Read and discard a null-terminated string containing the filename - while (1): - s=self.fileobj.read(1) - if not s or s=='\000': break - if flag & FCOMMENT: - # Read and discard a null-terminated string containing a comment - while (1): - s=self.fileobj.read(1) - if not s or s=='\000': break - if flag & FHCRC: - self.fileobj.read(2) # Read & discard the 16-bit header CRC + magic = self.fileobj.read(2) + if magic != '\037\213': + raise RuntimeError, 'Not a gzipped file' + method = ord( self.fileobj.read(1) ) + if method != 8: + raise RuntimeError, 'Unknown compression method' + flag = ord( self.fileobj.read(1) ) + # modtime = self.fileobj.read(4) + # extraflag = self.fileobj.read(1) + # os = self.fileobj.read(1) + self.fileobj.read(6) + + if flag & FEXTRA: + # Read & discard the extra field, if present + xlen=ord(self.fileobj.read(1)) + xlen=xlen+256*ord(self.fileobj.read(1)) + self.fileobj.read(xlen) + if flag & FNAME: + # Read and discard a null-terminated string containing the filename + while (1): + s=self.fileobj.read(1) + if not s or s=='\000': break + if flag & FCOMMENT: + # Read and discard a null-terminated string containing a comment + while (1): + s=self.fileobj.read(1) + if not s or s=='\000': break + if flag & FHCRC: + self.fileobj.read(2) # Read & discard the 16-bit header CRC def write(self,data): - if self.fileobj is None: - raise ValueError, "write() on closed GzipFile object" - if len(data) > 0: - self.size = self.size + len(data) - self.crc = zlib.crc32(data, self.crc) - self.fileobj.write( self.compress.compress(data) ) + if self.fileobj is None: + raise ValueError, "write() on closed GzipFile object" + if len(data) > 0: + self.size = self.size + len(data) + self.crc = zlib.crc32(data, self.crc) + self.fileobj.write( self.compress.compress(data) ) def writelines(self,lines): - self.write(string.join(lines)) + self.write(string.join(lines)) def read(self,size=None): - if self.extrasize <= 0 and self.fileobj is None: - return '' - - readsize = 1024 - if not size: # get the whole thing - try: - while 1: - self._read(readsize) - readsize = readsize * 2 - except EOFError: - size = self.extrasize - else: # just get some more of it - try: - while size > self.extrasize: - self._read(readsize) - readsize = readsize * 2 - except EOFError: - pass - - chunk = self.extrabuf[:size] - self.extrabuf = self.extrabuf[size:] - self.extrasize = self.extrasize - size - - return chunk + if self.extrasize <= 0 and self.fileobj is None: + return '' + + readsize = 1024 + if not size: # get the whole thing + try: + while 1: + self._read(readsize) + readsize = readsize * 2 + except EOFError: + size = self.extrasize + else: # just get some more of it + try: + while size > self.extrasize: + self._read(readsize) + readsize = readsize * 2 + except EOFError: + pass + + chunk = self.extrabuf[:size] + self.extrabuf = self.extrabuf[size:] + self.extrasize = self.extrasize - size + + return chunk def _unread(self, buf): - self.extrabuf = buf + self.extrabuf - self.extrasize = len(buf) + self.extrasize + self.extrabuf = buf + self.extrabuf + self.extrasize = len(buf) + self.extrasize def _read(self, size=1024): - try: - buf = self.fileobj.read(size) - except AttributeError: - raise EOFError, "Reached EOF" - if buf == "": - uncompress = self.decompress.flush() - if uncompress == "": - self._read_eof() - self.fileobj = None - raise EOFError, 'Reached EOF' - else: - uncompress = self.decompress.decompress(buf) - self.crc = zlib.crc32(uncompress, self.crc) - self.extrabuf = self.extrabuf + uncompress - self.extrasize = self.extrasize + len(uncompress) - self.size = self.size + len(uncompress) + try: + buf = self.fileobj.read(size) + except AttributeError: + raise EOFError, "Reached EOF" + if buf == "": + uncompress = self.decompress.flush() + if uncompress == "": + self._read_eof() + self.fileobj = None + raise EOFError, 'Reached EOF' + else: + uncompress = self.decompress.decompress(buf) + self.crc = zlib.crc32(uncompress, self.crc) + self.extrabuf = self.extrabuf + uncompress + self.extrasize = self.extrasize + len(uncompress) + self.size = self.size + len(uncompress) def _read_eof(self): - # Andrew writes: - ## We've read to the end of the file, so we have to rewind in order - ## to reread the 8 bytes containing the CRC and the file size. The - ## decompressor is smart and knows when to stop, so feeding it - ## extra data is harmless. - self.fileobj.seek(-8, 2) - crc32 = read32(self.fileobj) - isize = read32(self.fileobj) - if crc32 != self.crc: - self.error = "CRC check failed" - elif isize != self.size: - self.error = "Incorrect length of data produced" + # Andrew writes: + ## We've read to the end of the file, so we have to rewind in order + ## to reread the 8 bytes containing the CRC and the file size. The + ## decompressor is smart and knows when to stop, so feeding it + ## extra data is harmless. + self.fileobj.seek(-8, 2) + crc32 = read32(self.fileobj) + isize = read32(self.fileobj) + if crc32 != self.crc: + self.error = "CRC check failed" + elif isize != self.size: + self.error = "Incorrect length of data produced" def close(self): - if self.mode == WRITE: - self.fileobj.write(self.compress.flush()) - write32(self.fileobj, self.crc) - write32(self.fileobj, self.size) - self.fileobj = None - elif self.mode == READ: - self.fileobj = None - if self.myfileobj: - self.myfileobj.close() - self.myfileobj = None + if self.mode == WRITE: + self.fileobj.write(self.compress.flush()) + write32(self.fileobj, self.crc) + write32(self.fileobj, self.size) + self.fileobj = None + elif self.mode == READ: + self.fileobj = None + if self.myfileobj: + self.myfileobj.close() + self.myfileobj = None def flush(self): - self.fileobj.flush() + self.fileobj.flush() def seek(self): - raise IOError, 'Random access not allowed in gzip files' + raise IOError, 'Random access not allowed in gzip files' def tell(self): - raise IOError, 'I won\'t tell() you for gzip files' + raise IOError, 'I won\'t tell() you for gzip files' def isatty(self): - return 0 + return 0 def readline(self): - bufs = [] - readsize = 100 - while 1: - c = self.read(readsize) - i = string.find(c, '\n') - if i >= 0 or c == '': - bufs.append(c[:i]) - self._unread(c[i+1:]) - return string.join(bufs, '') - bufs.append(c) - readsize = readsize * 2 + bufs = [] + readsize = 100 + while 1: + c = self.read(readsize) + i = string.find(c, '\n') + if i >= 0 or c == '': + bufs.append(c[:i]) + self._unread(c[i+1:]) + return string.join(bufs, '') + bufs.append(c) + readsize = readsize * 2 def readlines(self): - buf = self.read() - return string.split(buf, '\n') + buf = self.read() + return string.split(buf, '\n') def writelines(self, L): - for line in L: - self.write(line) + for line in L: + self.write(line) def _test(): @@ -273,36 +273,36 @@ def _test(): args = sys.argv[1:] decompress = args and args[0] == "-d" if decompress: - args = args[1:] + args = args[1:] if not args: - args = ["-"] + args = ["-"] for arg in args: - if decompress: - if arg == "-": - f = GzipFile(filename="", mode="rb", fileobj=sys.stdin) - g = sys.stdout - else: - if arg[-3:] != ".gz": - print "filename doesn't end in .gz:", `arg` - continue - f = open(arg, "rb") - g = __builtin__.open(arg[:-3], "wb") - else: - if arg == "-": - f = sys.stdin - g = GzipFile(filename="", mode="wb", fileobj=sys.stdout) - else: - f = __builtin__.open(arg, "rb") - g = open(arg + ".gz", "wb") - while 1: - chunk = f.read(1024) - if not chunk: - break - g.write(chunk) - if g is not sys.stdout: - g.close() - if f is not sys.stdin: - f.close() + if decompress: + if arg == "-": + f = GzipFile(filename="", mode="rb", fileobj=sys.stdin) + g = sys.stdout + else: + if arg[-3:] != ".gz": + print "filename doesn't end in .gz:", `arg` + continue + f = open(arg, "rb") + g = __builtin__.open(arg[:-3], "wb") + else: + if arg == "-": + f = sys.stdin + g = GzipFile(filename="", mode="wb", fileobj=sys.stdout) + else: + f = __builtin__.open(arg, "rb") + g = open(arg + ".gz", "wb") + while 1: + chunk = f.read(1024) + if not chunk: + break + g.write(chunk) + if g is not sys.stdout: + g.close() + if f is not sys.stdin: + f.close() if __name__ == '__main__': _test() |