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authornkozlovskiy <nmk@ydb.tech>2023-09-29 12:24:06 +0300
committernkozlovskiy <nmk@ydb.tech>2023-09-29 12:41:34 +0300
commite0e3e1717e3d33762ce61950504f9637a6e669ed (patch)
treebca3ff6939b10ed60c3d5c12439963a1146b9711 /contrib/tools/python3/src/Lib/gzip.py
parent38f2c5852db84c7b4d83adfcb009eb61541d1ccd (diff)
downloadydb-e0e3e1717e3d33762ce61950504f9637a6e669ed.tar.gz
add ydb deps
Diffstat (limited to 'contrib/tools/python3/src/Lib/gzip.py')
-rw-r--r--contrib/tools/python3/src/Lib/gzip.py668
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diff --git a/contrib/tools/python3/src/Lib/gzip.py b/contrib/tools/python3/src/Lib/gzip.py
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+++ b/contrib/tools/python3/src/Lib/gzip.py
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+"""Functions that read and write gzipped files.
+
+The user of the file doesn't have to worry about the compression,
+but random access is not allowed."""
+
+# based on Andrew Kuchling's minigzip.py distributed with the zlib module
+
+import struct, sys, time, os
+import zlib
+import builtins
+import io
+import _compression
+
+__all__ = ["BadGzipFile", "GzipFile", "open", "compress", "decompress"]
+
+FTEXT, FHCRC, FEXTRA, FNAME, FCOMMENT = 1, 2, 4, 8, 16
+
+READ, WRITE = 1, 2
+
+_COMPRESS_LEVEL_FAST = 1
+_COMPRESS_LEVEL_TRADEOFF = 6
+_COMPRESS_LEVEL_BEST = 9
+
+
+def open(filename, mode="rb", compresslevel=_COMPRESS_LEVEL_BEST,
+ encoding=None, errors=None, newline=None):
+ """Open a gzip-compressed file in binary or text mode.
+
+ The filename argument can be an actual filename (a str or bytes object), or
+ an existing file object to read from or write to.
+
+ The mode argument can be "r", "rb", "w", "wb", "x", "xb", "a" or "ab" for
+ binary mode, or "rt", "wt", "xt" or "at" for text mode. The default mode is
+ "rb", and the default compresslevel is 9.
+
+ For binary mode, this function is equivalent to the GzipFile constructor:
+ GzipFile(filename, mode, compresslevel). In this case, the encoding, errors
+ and newline arguments must not be provided.
+
+ For text mode, a GzipFile object is created, and wrapped in an
+ io.TextIOWrapper instance with the specified encoding, error handling
+ behavior, and line ending(s).
+
+ """
+ if "t" in mode:
+ if "b" in mode:
+ raise ValueError("Invalid mode: %r" % (mode,))
+ else:
+ if encoding is not None:
+ raise ValueError("Argument 'encoding' not supported in binary mode")
+ if errors is not None:
+ raise ValueError("Argument 'errors' not supported in binary mode")
+ if newline is not None:
+ raise ValueError("Argument 'newline' not supported in binary mode")
+
+ gz_mode = mode.replace("t", "")
+ if isinstance(filename, (str, bytes, os.PathLike)):
+ binary_file = GzipFile(filename, gz_mode, compresslevel)
+ elif hasattr(filename, "read") or hasattr(filename, "write"):
+ binary_file = GzipFile(None, gz_mode, compresslevel, filename)
+ else:
+ raise TypeError("filename must be a str or bytes object, or a file")
+
+ if "t" in mode:
+ encoding = io.text_encoding(encoding)
+ return io.TextIOWrapper(binary_file, encoding, errors, newline)
+ else:
+ return binary_file
+
+def write32u(output, value):
+ # The L format writes the bit pattern correctly whether signed
+ # or unsigned.
+ output.write(struct.pack("<L", value))
+
+class _PaddedFile:
+ """Minimal read-only file object that prepends a string to the contents
+ of an actual file. Shouldn't be used outside of gzip.py, as it lacks
+ essential functionality."""
+
+ def __init__(self, f, prepend=b''):
+ self._buffer = prepend
+ self._length = len(prepend)
+ self.file = f
+ self._read = 0
+
+ def read(self, size):
+ if self._read is None:
+ return self.file.read(size)
+ if self._read + size <= self._length:
+ read = self._read
+ self._read += size
+ return self._buffer[read:self._read]
+ else:
+ read = self._read
+ self._read = None
+ return self._buffer[read:] + \
+ self.file.read(size-self._length+read)
+
+ def prepend(self, prepend=b''):
+ if self._read is None:
+ self._buffer = prepend
+ else: # Assume data was read since the last prepend() call
+ self._read -= len(prepend)
+ return
+ self._length = len(self._buffer)
+ self._read = 0
+
+ def seek(self, off):
+ self._read = None
+ self._buffer = None
+ return self.file.seek(off)
+
+ def seekable(self):
+ return True # Allows fast-forwarding even in unseekable streams
+
+
+class BadGzipFile(OSError):
+ """Exception raised in some cases for invalid gzip files."""
+
+
+class GzipFile(_compression.BaseStream):
+ """The GzipFile class simulates most of the methods of a file object with
+ the exception of the truncate() method.
+
+ This class only supports opening files in binary mode. If you need to open a
+ compressed file in text mode, use the gzip.open() function.
+
+ """
+
+ # Overridden with internal file object to be closed, if only a filename
+ # is passed in
+ myfileobj = None
+
+ def __init__(self, filename=None, mode=None,
+ compresslevel=_COMPRESS_LEVEL_BEST, fileobj=None, mtime=None):
+ """Constructor for the GzipFile class.
+
+ At least one of fileobj and filename must be given a
+ non-trivial value.
+
+ The new class instance is based on fileobj, which can be a regular
+ file, an io.BytesIO object, or any other object which simulates a file.
+ It defaults to None, in which case filename is opened to provide
+ a file object.
+
+ When fileobj is not None, the filename argument is only used to be
+ included in the gzip file header, which may include the original
+ filename of the uncompressed file. It defaults to the filename of
+ fileobj, if discernible; otherwise, it defaults to the empty string,
+ and in this case the original filename is not included in the header.
+
+ The mode argument can be any of 'r', 'rb', 'a', 'ab', 'w', 'wb', 'x', or
+ 'xb' depending on whether the file will be read or written. The default
+ is the mode of fileobj if discernible; otherwise, the default is 'rb'.
+ A mode of 'r' is equivalent to one of 'rb', and similarly for 'w' and
+ 'wb', 'a' and 'ab', and 'x' and 'xb'.
+
+ The compresslevel argument is an integer from 0 to 9 controlling the
+ level of compression; 1 is fastest and produces the least compression,
+ and 9 is slowest and produces the most compression. 0 is no compression
+ at all. The default is 9.
+
+ The mtime argument is an optional numeric timestamp to be written
+ to the last modification time field in the stream when compressing.
+ If omitted or None, the current time is used.
+
+ """
+
+ if mode and ('t' in mode or 'U' in mode):
+ raise ValueError("Invalid mode: {!r}".format(mode))
+ if mode and 'b' not in mode:
+ mode += 'b'
+ if fileobj is None:
+ fileobj = self.myfileobj = builtins.open(filename, mode or 'rb')
+ if filename is None:
+ filename = getattr(fileobj, 'name', '')
+ if not isinstance(filename, (str, bytes)):
+ filename = ''
+ else:
+ filename = os.fspath(filename)
+ origmode = mode
+ if mode is None:
+ mode = getattr(fileobj, 'mode', 'rb')
+
+ if mode.startswith('r'):
+ self.mode = READ
+ raw = _GzipReader(fileobj)
+ self._buffer = io.BufferedReader(raw)
+ self.name = filename
+
+ elif mode.startswith(('w', 'a', 'x')):
+ if origmode is None:
+ import warnings
+ warnings.warn(
+ "GzipFile was opened for writing, but this will "
+ "change in future Python releases. "
+ "Specify the mode argument for opening it for writing.",
+ FutureWarning, 2)
+ self.mode = WRITE
+ self._init_write(filename)
+ self.compress = zlib.compressobj(compresslevel,
+ zlib.DEFLATED,
+ -zlib.MAX_WBITS,
+ zlib.DEF_MEM_LEVEL,
+ 0)
+ self._write_mtime = mtime
+ else:
+ raise ValueError("Invalid mode: {!r}".format(mode))
+
+ self.fileobj = fileobj
+
+ if self.mode == WRITE:
+ self._write_gzip_header(compresslevel)
+
+ @property
+ def filename(self):
+ import warnings
+ warnings.warn("use the name attribute", DeprecationWarning, 2)
+ if self.mode == WRITE and self.name[-3:] != ".gz":
+ return self.name + ".gz"
+ return self.name
+
+ @property
+ def mtime(self):
+ """Last modification time read from stream, or None"""
+ return self._buffer.raw._last_mtime
+
+ def __repr__(self):
+ s = repr(self.fileobj)
+ return '<gzip ' + s[1:-1] + ' ' + hex(id(self)) + '>'
+
+ def _init_write(self, filename):
+ self.name = filename
+ self.crc = zlib.crc32(b"")
+ self.size = 0
+ self.writebuf = []
+ self.bufsize = 0
+ self.offset = 0 # Current file offset for seek(), tell(), etc
+
+ def _write_gzip_header(self, compresslevel):
+ self.fileobj.write(b'\037\213') # magic header
+ self.fileobj.write(b'\010') # compression method
+ try:
+ # RFC 1952 requires the FNAME field to be Latin-1. Do not
+ # include filenames that cannot be represented that way.
+ fname = os.path.basename(self.name)
+ if not isinstance(fname, bytes):
+ fname = fname.encode('latin-1')
+ if fname.endswith(b'.gz'):
+ fname = fname[:-3]
+ except UnicodeEncodeError:
+ fname = b''
+ flags = 0
+ if fname:
+ flags = FNAME
+ self.fileobj.write(chr(flags).encode('latin-1'))
+ mtime = self._write_mtime
+ if mtime is None:
+ mtime = time.time()
+ write32u(self.fileobj, int(mtime))
+ 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')
+
+ def write(self,data):
+ self._check_not_closed()
+ if self.mode != WRITE:
+ import errno
+ raise OSError(errno.EBADF, "write() on read-only GzipFile object")
+
+ if self.fileobj is None:
+ raise ValueError("write() on closed GzipFile object")
+
+ if isinstance(data, (bytes, bytearray)):
+ length = len(data)
+ else:
+ # accept any data that supports the buffer protocol
+ data = memoryview(data)
+ length = data.nbytes
+
+ if length > 0:
+ self.fileobj.write(self.compress.compress(data))
+ self.size += length
+ self.crc = zlib.crc32(data, self.crc)
+ self.offset += length
+
+ return length
+
+ def read(self, size=-1):
+ self._check_not_closed()
+ if self.mode != READ:
+ import errno
+ raise OSError(errno.EBADF, "read() on write-only GzipFile object")
+ return self._buffer.read(size)
+
+ def read1(self, size=-1):
+ """Implements BufferedIOBase.read1()
+
+ Reads up to a buffer's worth of data if size is negative."""
+ self._check_not_closed()
+ if self.mode != READ:
+ import errno
+ raise OSError(errno.EBADF, "read1() on write-only GzipFile object")
+
+ if size < 0:
+ size = io.DEFAULT_BUFFER_SIZE
+ return self._buffer.read1(size)
+
+ def peek(self, n):
+ self._check_not_closed()
+ if self.mode != READ:
+ import errno
+ raise OSError(errno.EBADF, "peek() on write-only GzipFile object")
+ return self._buffer.peek(n)
+
+ @property
+ def closed(self):
+ return self.fileobj is None
+
+ def close(self):
+ fileobj = self.fileobj
+ if fileobj is None:
+ return
+ self.fileobj = None
+ try:
+ if self.mode == WRITE:
+ fileobj.write(self.compress.flush())
+ write32u(fileobj, self.crc)
+ # self.size may exceed 2 GiB, or even 4 GiB
+ write32u(fileobj, self.size & 0xffffffff)
+ elif self.mode == READ:
+ self._buffer.close()
+ finally:
+ myfileobj = self.myfileobj
+ if myfileobj:
+ self.myfileobj = None
+ myfileobj.close()
+
+ def flush(self,zlib_mode=zlib.Z_SYNC_FLUSH):
+ self._check_not_closed()
+ if self.mode == WRITE:
+ # Ensure the compressor's buffer is flushed
+ self.fileobj.write(self.compress.flush(zlib_mode))
+ self.fileobj.flush()
+
+ def fileno(self):
+ """Invoke the underlying file object's fileno() method.
+
+ This will raise AttributeError if the underlying file object
+ doesn't support fileno().
+ """
+ return self.fileobj.fileno()
+
+ def rewind(self):
+ '''Return the uncompressed stream file position indicator to the
+ beginning of the file'''
+ if self.mode != READ:
+ raise OSError("Can't rewind in write mode")
+ self._buffer.seek(0)
+
+ def readable(self):
+ return self.mode == READ
+
+ def writable(self):
+ return self.mode == WRITE
+
+ def seekable(self):
+ return True
+
+ def seek(self, offset, whence=io.SEEK_SET):
+ if self.mode == WRITE:
+ if whence != io.SEEK_SET:
+ if whence == io.SEEK_CUR:
+ offset = self.offset + offset
+ else:
+ raise ValueError('Seek from end not supported')
+ if offset < self.offset:
+ raise OSError('Negative seek in write mode')
+ count = offset - self.offset
+ chunk = b'\0' * 1024
+ for i in range(count // 1024):
+ self.write(chunk)
+ self.write(b'\0' * (count % 1024))
+ elif self.mode == READ:
+ self._check_not_closed()
+ return self._buffer.seek(offset, whence)
+
+ return self.offset
+
+ def readline(self, size=-1):
+ self._check_not_closed()
+ return self._buffer.readline(size)
+
+
+def _read_exact(fp, n):
+ '''Read exactly *n* bytes from `fp`
+
+ This method is required because fp may be unbuffered,
+ i.e. return short reads.
+ '''
+ data = fp.read(n)
+ while len(data) < n:
+ b = fp.read(n - len(data))
+ if not b:
+ raise EOFError("Compressed file ended before the "
+ "end-of-stream marker was reached")
+ data += b
+ return data
+
+
+def _read_gzip_header(fp):
+ '''Read a gzip header from `fp` and progress to the end of the header.
+
+ Returns last mtime if header was present or None otherwise.
+ '''
+ magic = fp.read(2)
+ if magic == b'':
+ return None
+
+ if magic != b'\037\213':
+ raise BadGzipFile('Not a gzipped file (%r)' % magic)
+
+ (method, flag, last_mtime) = struct.unpack("<BBIxx", _read_exact(fp, 8))
+ if method != 8:
+ raise BadGzipFile('Unknown compression method')
+
+ if flag & FEXTRA:
+ # Read & discard the extra field, if present
+ extra_len, = struct.unpack("<H", _read_exact(fp, 2))
+ _read_exact(fp, extra_len)
+ if flag & FNAME:
+ # Read and discard a null-terminated string containing the filename
+ while True:
+ s = fp.read(1)
+ if not s or s==b'\000':
+ break
+ if flag & FCOMMENT:
+ # Read and discard a null-terminated string containing a comment
+ while True:
+ s = fp.read(1)
+ if not s or s==b'\000':
+ break
+ if flag & FHCRC:
+ _read_exact(fp, 2) # Read & discard the 16-bit header CRC
+ return last_mtime
+
+
+class _GzipReader(_compression.DecompressReader):
+ def __init__(self, fp):
+ super().__init__(_PaddedFile(fp), zlib.decompressobj,
+ wbits=-zlib.MAX_WBITS)
+ # Set flag indicating start of a new member
+ self._new_member = True
+ self._last_mtime = None
+
+ def _init_read(self):
+ self._crc = zlib.crc32(b"")
+ self._stream_size = 0 # Decompressed size of unconcatenated stream
+
+ def _read_gzip_header(self):
+ last_mtime = _read_gzip_header(self._fp)
+ if last_mtime is None:
+ return False
+ self._last_mtime = last_mtime
+ return True
+
+ def read(self, size=-1):
+ if size < 0:
+ return self.readall()
+ # size=0 is special because decompress(max_length=0) is not supported
+ if not size:
+ return b""
+
+ # For certain input data, a single
+ # call to decompress() may not return
+ # any data. In this case, retry until we get some data or reach EOF.
+ while True:
+ if self._decompressor.eof:
+ # Ending case: we've come to the end of a member in the file,
+ # so finish up this member, and read a new gzip header.
+ # Check the CRC and file size, and set the flag so we read
+ # a new member
+ self._read_eof()
+ self._new_member = True
+ self._decompressor = self._decomp_factory(
+ **self._decomp_args)
+
+ if self._new_member:
+ # If the _new_member flag is set, we have to
+ # jump to the next member, if there is one.
+ self._init_read()
+ if not self._read_gzip_header():
+ self._size = self._pos
+ return b""
+ self._new_member = False
+
+ # Read a chunk of data from the file
+ buf = self._fp.read(io.DEFAULT_BUFFER_SIZE)
+
+ uncompress = self._decompressor.decompress(buf, size)
+ if self._decompressor.unconsumed_tail != b"":
+ self._fp.prepend(self._decompressor.unconsumed_tail)
+ elif self._decompressor.unused_data != b"":
+ # Prepend the already read bytes to the fileobj so they can
+ # be seen by _read_eof() and _read_gzip_header()
+ self._fp.prepend(self._decompressor.unused_data)
+
+ if uncompress != b"":
+ break
+ if buf == b"":
+ raise EOFError("Compressed file ended before the "
+ "end-of-stream marker was reached")
+
+ self._add_read_data( uncompress )
+ self._pos += len(uncompress)
+ return uncompress
+
+ def _add_read_data(self, data):
+ self._crc = zlib.crc32(data, self._crc)
+ self._stream_size = self._stream_size + len(data)
+
+ def _read_eof(self):
+ # We've read to the end of the file
+ # We check that the computed CRC and size of the
+ # uncompressed data matches the stored values. Note that the size
+ # stored is the true file size mod 2**32.
+ crc32, isize = struct.unpack("<II", _read_exact(self._fp, 8))
+ if crc32 != self._crc:
+ raise BadGzipFile("CRC check failed %s != %s" % (hex(crc32),
+ hex(self._crc)))
+ elif isize != (self._stream_size & 0xffffffff):
+ raise BadGzipFile("Incorrect length of data produced")
+
+ # Gzip files can be padded with zeroes and still have archives.
+ # Consume all zero bytes and set the file position to the first
+ # non-zero byte. See http://www.gzip.org/#faq8
+ c = b"\x00"
+ while c == b"\x00":
+ c = self._fp.read(1)
+ if c:
+ self._fp.prepend(c)
+
+ def _rewind(self):
+ super()._rewind()
+ self._new_member = True
+
+
+def _create_simple_gzip_header(compresslevel: int,
+ mtime = None) -> bytes:
+ """
+ Write a simple gzip header with no extra fields.
+ :param compresslevel: Compresslevel used to determine the xfl bytes.
+ :param mtime: The mtime (must support conversion to a 32-bit integer).
+ :return: A bytes object representing the gzip header.
+ """
+ if mtime is None:
+ mtime = time.time()
+ if compresslevel == _COMPRESS_LEVEL_BEST:
+ xfl = 2
+ elif compresslevel == _COMPRESS_LEVEL_FAST:
+ xfl = 4
+ else:
+ xfl = 0
+ # Pack ID1 and ID2 magic bytes, method (8=deflate), header flags (no extra
+ # fields added to header), mtime, xfl and os (255 for unknown OS).
+ return struct.pack("<BBBBLBB", 0x1f, 0x8b, 8, 0, int(mtime), xfl, 255)
+
+
+def compress(data, compresslevel=_COMPRESS_LEVEL_BEST, *, mtime=None):
+ """Compress data in one shot and return the compressed string.
+
+ compresslevel sets the compression level in range of 0-9.
+ mtime can be used to set the modification time. The modification time is
+ set to the current time by default.
+ """
+ if mtime == 0:
+ # Use zlib as it creates the header with 0 mtime by default.
+ # This is faster and with less overhead.
+ return zlib.compress(data, level=compresslevel, wbits=31)
+ header = _create_simple_gzip_header(compresslevel, mtime)
+ trailer = struct.pack("<LL", zlib.crc32(data), (len(data) & 0xffffffff))
+ # Wbits=-15 creates a raw deflate block.
+ return (header + zlib.compress(data, level=compresslevel, wbits=-15) +
+ trailer)
+
+
+def decompress(data):
+ """Decompress a gzip compressed string in one shot.
+ Return the decompressed string.
+ """
+ decompressed_members = []
+ while True:
+ fp = io.BytesIO(data)
+ if _read_gzip_header(fp) is None:
+ return b"".join(decompressed_members)
+ # Use a zlib raw deflate compressor
+ do = zlib.decompressobj(wbits=-zlib.MAX_WBITS)
+ # Read all the data except the header
+ decompressed = do.decompress(data[fp.tell():])
+ if not do.eof or len(do.unused_data) < 8:
+ raise EOFError("Compressed file ended before the end-of-stream "
+ "marker was reached")
+ crc, length = struct.unpack("<II", do.unused_data[:8])
+ if crc != zlib.crc32(decompressed):
+ raise BadGzipFile("CRC check failed")
+ if length != (len(decompressed) & 0xffffffff):
+ raise BadGzipFile("Incorrect length of data produced")
+ decompressed_members.append(decompressed)
+ data = do.unused_data[8:].lstrip(b"\x00")
+
+
+def main():
+ from argparse import ArgumentParser
+ parser = ArgumentParser(description=
+ "A simple command line interface for the gzip module: act like gzip, "
+ "but do not delete the input file.")
+ group = parser.add_mutually_exclusive_group()
+ group.add_argument('--fast', action='store_true', help='compress faster')
+ group.add_argument('--best', action='store_true', help='compress better')
+ group.add_argument("-d", "--decompress", action="store_true",
+ help="act like gunzip instead of gzip")
+
+ parser.add_argument("args", nargs="*", default=["-"], metavar='file')
+ args = parser.parse_args()
+
+ compresslevel = _COMPRESS_LEVEL_TRADEOFF
+ if args.fast:
+ compresslevel = _COMPRESS_LEVEL_FAST
+ elif args.best:
+ compresslevel = _COMPRESS_LEVEL_BEST
+
+ for arg in args.args:
+ if args.decompress:
+ if arg == "-":
+ f = GzipFile(filename="", mode="rb", fileobj=sys.stdin.buffer)
+ g = sys.stdout.buffer
+ else:
+ if arg[-3:] != ".gz":
+ sys.exit(f"filename doesn't end in .gz: {arg!r}")
+ f = open(arg, "rb")
+ g = builtins.open(arg[:-3], "wb")
+ else:
+ if arg == "-":
+ f = sys.stdin.buffer
+ g = GzipFile(filename="", mode="wb", fileobj=sys.stdout.buffer,
+ compresslevel=compresslevel)
+ else:
+ f = builtins.open(arg, "rb")
+ g = open(arg + ".gz", "wb")
+ while True:
+ chunk = f.read(io.DEFAULT_BUFFER_SIZE)
+ if not chunk:
+ break
+ g.write(chunk)
+ if g is not sys.stdout.buffer:
+ g.close()
+ if f is not sys.stdin.buffer:
+ f.close()
+
+if __name__ == '__main__':
+ main()