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Diffstat (limited to 'modules/language/python/module/#bz2.py#')
| -rw-r--r-- | modules/language/python/module/#bz2.py# | 362 |
1 files changed, 0 insertions, 362 deletions
diff --git a/modules/language/python/module/#bz2.py# b/modules/language/python/module/#bz2.py# deleted file mode 100644 index 3740792..0000000 --- a/modules/language/python/module/#bz2.py# +++ /dev/null @@ -1,362 +0,0 @@ -module(bz2) -"""Interface to the libbzip2 compression library. - -This module provides a file interface, classes for incremental -(de)compression, and functions for one-shot (de)compression. -""" - -__all__ = ["BZ2File", "BZ2Compressor", "BZ2Decompressor", - "open", "compress", "decompress"] - -__author__ = "Nadeem Vawda <nadeem.vawda@gmail.com>" - -from builtins import open as _builtin_open -import io -import os -import warnings -import _compression - -try: - from threading import RLock -except ImportError: - from dummy_threading import RLock - -from _bz2 import BZ2Compressor, BZ2Decompressor - - -_MODE_CLOSED = 0 -_MODE_READ = 1 -# Value 2 no longer used -_MODE_WRITE = 3 - - -class BZ2File(_compression.BaseStream): - - """A file object providing transparent bzip2 (de)compression. - - A BZ2File can act as a wrapper for an existing file object, or refer - directly to a named file on disk. - - Note that BZ2File provides a *binary* file interface - data read is - returned as bytes, and data to be written should be given as bytes. - """ - - def __init__(self, filename, mode="r", buffering=None, compresslevel=9): - """Open a bzip2-compressed file. - - If filename is a str, bytes, or PathLike object, it gives the - name of the file to be opened. Otherwise, it should be a file - object, which will be used to read or write the compressed data. - - mode can be 'r' for reading (default), 'w' for (over)writing, - 'x' for creating exclusively, or 'a' for appending. These can - equivalently be given as 'rb', 'wb', 'xb', and 'ab'. - - buffering is ignored. Its use is deprecated. - - If mode is 'w', 'x' or 'a', compresslevel can be a number between 1 - and 9 specifying the level of compression: 1 produces the least - compression, and 9 (default) produces the most compression. - - If mode is 'r', the input file may be the concatenation of - multiple compressed streams. - """ - # This lock must be recursive, so that BufferedIOBase's - # writelines() does not deadlock. - self._lock = RLock() - self._fp = None - self._closefp = False - self._mode = _MODE_CLOSED - - if buffering is not None: - warnings.warn("Use of 'buffering' argument is deprecated", - DeprecationWarning) - - if not (1 <= compresslevel <= 9): - raise ValueError("compresslevel must be between 1 and 9") - - if mode in ("", "r", "rb"): - mode = "rb" - mode_code = _MODE_READ - elif mode in ("w", "wb"): - mode = "wb" - mode_code = _MODE_WRITE - self._compressor = BZ2Compressor(compresslevel) - elif mode in ("x", "xb"): - mode = "xb" - mode_code = _MODE_WRITE - self._compressor = BZ2Compressor(compresslevel) - elif mode in ("a", "ab"): - mode = "ab" - mode_code = _MODE_WRITE - self._compressor = BZ2Compressor(compresslevel) - else: - raise ValueError("Invalid mode: %r" % (mode,)) - - if isinstance(filename, (str, bytes, os.PathLike)): - self._fp = _builtin_open(filename, mode) - self._closefp = True - self._mode = mode_code - elif hasattr(filename, "read") or hasattr(filename, "write"): - self._fp = filename - self._mode = mode_code - else: - raise TypeError("filename must be a str, bytes, file or PathLike object") - - if self._mode == _MODE_READ: - raw = _compression.DecompressReader(self._fp, - BZ2Decompressor, trailing_error=OSError) - self._buffer = io.BufferedReader(raw) - else: - self._pos = 0 - - def close(self): - """Flush and close the file. - - May be called more than once without error. Once the file is - closed, any other operation on it will raise a ValueError. - """ - with self._lock: - if self._mode == _MODE_CLOSED: - return - try: - if self._mode == _MODE_READ: - self._buffer.close() - elif self._mode == _MODE_WRITE: - self._fp.write(self._compressor.flush()) - self._compressor = None - finally: - try: - if self._closefp: - self._fp.close() - finally: - self._fp = None - self._closefp = False - self._mode = _MODE_CLOSED - self._buffer = None - - @property - def closed(self): - """True if this file is closed.""" - return self._mode == _MODE_CLOSED - - def fileno(self): - """Return the file descriptor for the underlying file.""" - self._check_not_closed() - return self._fp.fileno() - - def seekable(self): - """Return whether the file supports seeking.""" - return self.readable() and self._buffer.seekable() - - def readable(self): - """Return whether the file was opened for reading.""" - self._check_not_closed() - return self._mode == _MODE_READ - - def writable(self): - """Return whether the file was opened for writing.""" - self._check_not_closed() - return self._mode == _MODE_WRITE - - def peek(self, n=0): - """Return buffered data without advancing the file position. - - Always returns at least one byte of data, unless at EOF. - The exact number of bytes returned is unspecified. - """ - with self._lock: - self._check_can_read() - # Relies on the undocumented fact that BufferedReader.peek() - # always returns at least one byte (except at EOF), independent - # of the value of n - return self._buffer.peek(n) - - def read(self, size=-1): - """Read up to size uncompressed bytes from the file. - - If size is negative or omitted, read until EOF is reached. - Returns b'' if the file is already at EOF. - """ - with self._lock: - self._check_can_read() - return self._buffer.read(size) - - def read1(self, size=-1): - """Read up to size uncompressed bytes, while trying to avoid - making multiple reads from the underlying stream. Reads up to a - buffer's worth of data if size is negative. - - Returns b'' if the file is at EOF. - """ - with self._lock: - self._check_can_read() - if size < 0: - size = io.DEFAULT_BUFFER_SIZE - return self._buffer.read1(size) - - def readinto(self, b): - """Read bytes into b. - - Returns the number of bytes read (0 for EOF). - """ - with self._lock: - self._check_can_read() - return self._buffer.readinto(b) - - def readline(self, size=-1): - """Read a line of uncompressed bytes from the file. - - The terminating newline (if present) is retained. If size is - non-negative, no more than size bytes will be read (in which - case the line may be incomplete). Returns b'' if already at EOF. - """ - if not isinstance(size, int): - if not hasattr(size, "__index__"): - raise TypeError("Integer argument expected") - size = size.__index__() - with self._lock: - self._check_can_read() - return self._buffer.readline(size) - - def readlines(self, size=-1): - """Read a list of lines of uncompressed bytes from the file. - - size can be specified to control the number of lines read: no - further lines will be read once the total size of the lines read - so far equals or exceeds size. - """ - if not isinstance(size, int): - if not hasattr(size, "__index__"): - raise TypeError("Integer argument expected") - size = size.__index__() - with self._lock: - self._check_can_read() - return self._buffer.readlines(size) - - def write(self, data): - """Write a byte string to the file. - - Returns the number of uncompressed bytes written, which is - always len(data). Note that due to buffering, the file on disk - may not reflect the data written until close() is called. - """ - with self._lock: - self._check_can_write() - compressed = self._compressor.compress(data) - self._fp.write(compressed) - self._pos += len(data) - return len(data) - - def writelines(self, seq): - """Write a sequence of byte strings to the file. - - Returns the number of uncompressed bytes written. - seq can be any iterable yielding byte strings. - - Line separators are not added between the written byte strings. - """ - with self._lock: - return _compression.BaseStream.writelines(self, seq) - - def seek(self, offset, whence=io.SEEK_SET): - """Change the file position. - - The new position is specified by offset, relative to the - position indicated by whence. Values for whence are: - - 0: start of stream (default); offset must not be negative - 1: current stream position - 2: end of stream; offset must not be positive - - Returns the new file position. - - Note that seeking is emulated, so depending on the parameters, - this operation may be extremely slow. - """ - with self._lock: - self._check_can_seek() - return self._buffer.seek(offset, whence) - - def tell(self): - """Return the current file position.""" - with self._lock: - self._check_not_closed() - if self._mode == _MODE_READ: - return self._buffer.tell() - return self._pos - - -def open(filename, mode="rb", compresslevel=9, - encoding=None, errors=None, newline=None): - """Open a bzip2-compressed file in binary or text mode. - - The filename argument can be an actual filename (a str, bytes, or - PathLike 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 BZ2File - constructor: BZ2File(filename, mode, compresslevel). In this case, - the encoding, errors and newline arguments must not be provided. - - For text mode, a BZ2File 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") - - bz_mode = mode.replace("t", "") - binary_file = BZ2File(filename, bz_mode, compresslevel=compresslevel) - - if "t" in mode: - return io.TextIOWrapper(binary_file, encoding, errors, newline) - else: - return binary_file - - -def compress(data, compresslevel=9): - """Compress a block of data. - - compresslevel, if given, must be a number between 1 and 9. - - For incremental compression, use a BZ2Compressor object instead. - """ - comp = BZ2Compressor(compresslevel) - return comp.compress(data) + comp.flush() - - -def decompress(data): - """Decompress a block of data. - - For incremental decompression, use a BZ2Decompressor object instead. - """ - results = [] - while data: - decomp = BZ2Decompressor() - try: - res = decomp.decompress(data) - except OSError: - if results: - break # Leftover data is not a valid bzip2 stream; ignore it. - else: - raise # Error on the first iteration; bail out. - results.append(res) - if not decomp.eof: - raise ValueError("Compressed data ended before the " - "end-of-stream marker was reached") - data = decomp.unused_data - return b"".join(results) |