Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 1 | """Interface to the liblzma compression library. |
| 2 | |
| 3 | This module provides a class for reading and writing compressed files, |
| 4 | classes for incremental (de)compression, and convenience functions for |
| 5 | one-shot (de)compression. |
| 6 | |
| 7 | These classes and functions support both the XZ and legacy LZMA |
| 8 | container formats, as well as raw compressed data streams. |
| 9 | """ |
| 10 | |
| 11 | __all__ = [ |
| 12 | "CHECK_NONE", "CHECK_CRC32", "CHECK_CRC64", "CHECK_SHA256", |
| 13 | "CHECK_ID_MAX", "CHECK_UNKNOWN", |
| 14 | "FILTER_LZMA1", "FILTER_LZMA2", "FILTER_DELTA", "FILTER_X86", "FILTER_IA64", |
| 15 | "FILTER_ARM", "FILTER_ARMTHUMB", "FILTER_POWERPC", "FILTER_SPARC", |
| 16 | "FORMAT_AUTO", "FORMAT_XZ", "FORMAT_ALONE", "FORMAT_RAW", |
| 17 | "MF_HC3", "MF_HC4", "MF_BT2", "MF_BT3", "MF_BT4", |
| 18 | "MODE_FAST", "MODE_NORMAL", "PRESET_DEFAULT", "PRESET_EXTREME", |
| 19 | |
| 20 | "LZMACompressor", "LZMADecompressor", "LZMAFile", "LZMAError", |
Nadeem Vawda | e860404 | 2012-06-04 23:38:12 +0200 | [diff] [blame] | 21 | "open", "compress", "decompress", "is_check_supported", |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 22 | ] |
| 23 | |
Nadeem Vawda | e860404 | 2012-06-04 23:38:12 +0200 | [diff] [blame] | 24 | import builtins |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 25 | import io |
| 26 | from _lzma import * |
Nadeem Vawda | a425c3d | 2012-06-21 23:36:48 +0200 | [diff] [blame] | 27 | from _lzma import _encode_filter_properties, _decode_filter_properties |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 28 | |
| 29 | |
| 30 | _MODE_CLOSED = 0 |
| 31 | _MODE_READ = 1 |
| 32 | _MODE_READ_EOF = 2 |
| 33 | _MODE_WRITE = 3 |
| 34 | |
| 35 | _BUFFER_SIZE = 8192 |
| 36 | |
| 37 | |
| 38 | class LZMAFile(io.BufferedIOBase): |
| 39 | |
| 40 | """A file object providing transparent LZMA (de)compression. |
| 41 | |
| 42 | An LZMAFile can act as a wrapper for an existing file object, or |
| 43 | refer directly to a named file on disk. |
| 44 | |
| 45 | Note that LZMAFile provides a *binary* file interface - data read |
| 46 | is returned as bytes, and data to be written must be given as bytes. |
| 47 | """ |
| 48 | |
| 49 | def __init__(self, filename=None, mode="r", *, |
Nadeem Vawda | 33c34da | 2012-06-04 23:34:07 +0200 | [diff] [blame] | 50 | format=None, check=-1, preset=None, filters=None): |
| 51 | """Open an LZMA-compressed file in binary mode. |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 52 | |
Nadeem Vawda | 33c34da | 2012-06-04 23:34:07 +0200 | [diff] [blame] | 53 | filename can be either an actual file name (given as a str or |
| 54 | bytes object), in which case the named file is opened, or it can |
| 55 | be an existing file object to read from or write to. |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 56 | |
| 57 | mode can be "r" for reading (default), "w" for (over)writing, or |
Nadeem Vawda | 6cbb20c | 2012-06-04 23:36:24 +0200 | [diff] [blame] | 58 | "a" for appending. These can equivalently be given as "rb", "wb", |
| 59 | and "ab" respectively. |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 60 | |
| 61 | format specifies the container format to use for the file. |
| 62 | If mode is "r", this defaults to FORMAT_AUTO. Otherwise, the |
| 63 | default is FORMAT_XZ. |
| 64 | |
| 65 | check specifies the integrity check to use. This argument can |
| 66 | only be used when opening a file for writing. For FORMAT_XZ, |
| 67 | the default is CHECK_CRC64. FORMAT_ALONE and FORMAT_RAW do not |
| 68 | support integrity checks - for these formats, check must be |
| 69 | omitted, or be CHECK_NONE. |
| 70 | |
| 71 | When opening a file for reading, the *preset* argument is not |
| 72 | meaningful, and should be omitted. The *filters* argument should |
| 73 | also be omitted, except when format is FORMAT_RAW (in which case |
| 74 | it is required). |
| 75 | |
| 76 | When opening a file for writing, the settings used by the |
| 77 | compressor can be specified either as a preset compression |
| 78 | level (with the *preset* argument), or in detail as a custom |
| 79 | filter chain (with the *filters* argument). For FORMAT_XZ and |
| 80 | FORMAT_ALONE, the default is to use the PRESET_DEFAULT preset |
| 81 | level. For FORMAT_RAW, the caller must always specify a filter |
| 82 | chain; the raw compressor does not support preset compression |
| 83 | levels. |
| 84 | |
| 85 | preset (if provided) should be an integer in the range 0-9, |
| 86 | optionally OR-ed with the constant PRESET_EXTREME. |
| 87 | |
| 88 | filters (if provided) should be a sequence of dicts. Each dict |
| 89 | should have an entry for "id" indicating ID of the filter, plus |
| 90 | additional entries for options to the filter. |
| 91 | """ |
| 92 | self._fp = None |
| 93 | self._closefp = False |
| 94 | self._mode = _MODE_CLOSED |
| 95 | self._pos = 0 |
| 96 | self._size = -1 |
| 97 | |
Nadeem Vawda | 6cbb20c | 2012-06-04 23:36:24 +0200 | [diff] [blame] | 98 | if mode in ("r", "rb"): |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 99 | if check != -1: |
| 100 | raise ValueError("Cannot specify an integrity check " |
| 101 | "when opening a file for reading") |
| 102 | if preset is not None: |
| 103 | raise ValueError("Cannot specify a preset compression " |
| 104 | "level when opening a file for reading") |
| 105 | if format is None: |
| 106 | format = FORMAT_AUTO |
| 107 | mode_code = _MODE_READ |
| 108 | # Save the args to pass to the LZMADecompressor initializer. |
| 109 | # If the file contains multiple compressed streams, each |
| 110 | # stream will need a separate decompressor object. |
| 111 | self._init_args = {"format":format, "filters":filters} |
| 112 | self._decompressor = LZMADecompressor(**self._init_args) |
| 113 | self._buffer = None |
Nadeem Vawda | 6cbb20c | 2012-06-04 23:36:24 +0200 | [diff] [blame] | 114 | elif mode in ("w", "wb", "a", "ab"): |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 115 | if format is None: |
| 116 | format = FORMAT_XZ |
| 117 | mode_code = _MODE_WRITE |
| 118 | self._compressor = LZMACompressor(format=format, check=check, |
| 119 | preset=preset, filters=filters) |
| 120 | else: |
| 121 | raise ValueError("Invalid mode: {!r}".format(mode)) |
| 122 | |
Nadeem Vawda | 33c34da | 2012-06-04 23:34:07 +0200 | [diff] [blame] | 123 | if isinstance(filename, (str, bytes)): |
Nadeem Vawda | 6cbb20c | 2012-06-04 23:36:24 +0200 | [diff] [blame] | 124 | if "b" not in mode: |
| 125 | mode += "b" |
Nadeem Vawda | e860404 | 2012-06-04 23:38:12 +0200 | [diff] [blame] | 126 | self._fp = builtins.open(filename, mode) |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 127 | self._closefp = True |
| 128 | self._mode = mode_code |
Nadeem Vawda | 33c34da | 2012-06-04 23:34:07 +0200 | [diff] [blame] | 129 | elif hasattr(filename, "read") or hasattr(filename, "write"): |
| 130 | self._fp = filename |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 131 | self._mode = mode_code |
| 132 | else: |
Nadeem Vawda | 33c34da | 2012-06-04 23:34:07 +0200 | [diff] [blame] | 133 | raise TypeError("filename must be a str or bytes object, or a file") |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 134 | |
| 135 | def close(self): |
| 136 | """Flush and close the file. |
| 137 | |
| 138 | May be called more than once without error. Once the file is |
| 139 | closed, any other operation on it will raise a ValueError. |
| 140 | """ |
| 141 | if self._mode == _MODE_CLOSED: |
| 142 | return |
| 143 | try: |
| 144 | if self._mode in (_MODE_READ, _MODE_READ_EOF): |
| 145 | self._decompressor = None |
| 146 | self._buffer = None |
| 147 | elif self._mode == _MODE_WRITE: |
| 148 | self._fp.write(self._compressor.flush()) |
| 149 | self._compressor = None |
| 150 | finally: |
| 151 | try: |
| 152 | if self._closefp: |
| 153 | self._fp.close() |
| 154 | finally: |
| 155 | self._fp = None |
| 156 | self._closefp = False |
| 157 | self._mode = _MODE_CLOSED |
| 158 | |
| 159 | @property |
| 160 | def closed(self): |
| 161 | """True if this file is closed.""" |
| 162 | return self._mode == _MODE_CLOSED |
| 163 | |
| 164 | def fileno(self): |
| 165 | """Return the file descriptor for the underlying file.""" |
| 166 | self._check_not_closed() |
| 167 | return self._fp.fileno() |
| 168 | |
| 169 | def seekable(self): |
| 170 | """Return whether the file supports seeking.""" |
Nadeem Vawda | ae557d7 | 2012-02-12 01:51:38 +0200 | [diff] [blame] | 171 | return self.readable() and self._fp.seekable() |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 172 | |
| 173 | def readable(self): |
| 174 | """Return whether the file was opened for reading.""" |
| 175 | self._check_not_closed() |
| 176 | return self._mode in (_MODE_READ, _MODE_READ_EOF) |
| 177 | |
| 178 | def writable(self): |
| 179 | """Return whether the file was opened for writing.""" |
| 180 | self._check_not_closed() |
| 181 | return self._mode == _MODE_WRITE |
| 182 | |
| 183 | # Mode-checking helper functions. |
| 184 | |
| 185 | def _check_not_closed(self): |
| 186 | if self.closed: |
| 187 | raise ValueError("I/O operation on closed file") |
| 188 | |
| 189 | def _check_can_read(self): |
| 190 | if not self.readable(): |
| 191 | raise io.UnsupportedOperation("File not open for reading") |
| 192 | |
| 193 | def _check_can_write(self): |
| 194 | if not self.writable(): |
| 195 | raise io.UnsupportedOperation("File not open for writing") |
| 196 | |
| 197 | def _check_can_seek(self): |
Nadeem Vawda | ae557d7 | 2012-02-12 01:51:38 +0200 | [diff] [blame] | 198 | if not self.readable(): |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 199 | raise io.UnsupportedOperation("Seeking is only supported " |
| 200 | "on files open for reading") |
Nadeem Vawda | ae557d7 | 2012-02-12 01:51:38 +0200 | [diff] [blame] | 201 | if not self._fp.seekable(): |
| 202 | raise io.UnsupportedOperation("The underlying file object " |
| 203 | "does not support seeking") |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 204 | |
| 205 | # Fill the readahead buffer if it is empty. Returns False on EOF. |
| 206 | def _fill_buffer(self): |
Nadeem Vawda | 37d3ff1 | 2012-08-05 02:19:09 +0200 | [diff] [blame] | 207 | # Depending on the input data, our call to the decompressor may not |
| 208 | # return any data. In this case, try again after reading another block. |
| 209 | while True: |
| 210 | if self._buffer: |
| 211 | return True |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 212 | |
Nadeem Vawda | 37d3ff1 | 2012-08-05 02:19:09 +0200 | [diff] [blame] | 213 | if self._decompressor.unused_data: |
| 214 | rawblock = self._decompressor.unused_data |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 215 | else: |
Nadeem Vawda | 37d3ff1 | 2012-08-05 02:19:09 +0200 | [diff] [blame] | 216 | rawblock = self._fp.read(_BUFFER_SIZE) |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 217 | |
Nadeem Vawda | 37d3ff1 | 2012-08-05 02:19:09 +0200 | [diff] [blame] | 218 | if not rawblock: |
| 219 | if self._decompressor.eof: |
| 220 | self._mode = _MODE_READ_EOF |
| 221 | self._size = self._pos |
| 222 | return False |
| 223 | else: |
| 224 | raise EOFError("Compressed file ended before the " |
| 225 | "end-of-stream marker was reached") |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 226 | |
Nadeem Vawda | 37d3ff1 | 2012-08-05 02:19:09 +0200 | [diff] [blame] | 227 | # Continue to next stream. |
| 228 | if self._decompressor.eof: |
| 229 | self._decompressor = LZMADecompressor(**self._init_args) |
| 230 | |
| 231 | self._buffer = self._decompressor.decompress(rawblock) |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 232 | |
| 233 | # Read data until EOF. |
| 234 | # If return_data is false, consume the data without returning it. |
| 235 | def _read_all(self, return_data=True): |
| 236 | blocks = [] |
| 237 | while self._fill_buffer(): |
| 238 | if return_data: |
| 239 | blocks.append(self._buffer) |
| 240 | self._pos += len(self._buffer) |
| 241 | self._buffer = None |
| 242 | if return_data: |
| 243 | return b"".join(blocks) |
| 244 | |
| 245 | # Read a block of up to n bytes. |
| 246 | # If return_data is false, consume the data without returning it. |
| 247 | def _read_block(self, n, return_data=True): |
| 248 | blocks = [] |
| 249 | while n > 0 and self._fill_buffer(): |
| 250 | if n < len(self._buffer): |
| 251 | data = self._buffer[:n] |
| 252 | self._buffer = self._buffer[n:] |
| 253 | else: |
| 254 | data = self._buffer |
| 255 | self._buffer = None |
| 256 | if return_data: |
| 257 | blocks.append(data) |
| 258 | self._pos += len(data) |
| 259 | n -= len(data) |
| 260 | if return_data: |
| 261 | return b"".join(blocks) |
| 262 | |
| 263 | def peek(self, size=-1): |
| 264 | """Return buffered data without advancing the file position. |
| 265 | |
| 266 | Always returns at least one byte of data, unless at EOF. |
| 267 | The exact number of bytes returned is unspecified. |
| 268 | """ |
| 269 | self._check_can_read() |
| 270 | if self._mode == _MODE_READ_EOF or not self._fill_buffer(): |
| 271 | return b"" |
| 272 | return self._buffer |
| 273 | |
| 274 | def read(self, size=-1): |
| 275 | """Read up to size uncompressed bytes from the file. |
| 276 | |
| 277 | If size is negative or omitted, read until EOF is reached. |
| 278 | Returns b"" if the file is already at EOF. |
| 279 | """ |
| 280 | self._check_can_read() |
| 281 | if self._mode == _MODE_READ_EOF or size == 0: |
| 282 | return b"" |
| 283 | elif size < 0: |
| 284 | return self._read_all() |
| 285 | else: |
| 286 | return self._read_block(size) |
| 287 | |
| 288 | def read1(self, size=-1): |
Nadeem Vawda | 37d3ff1 | 2012-08-05 02:19:09 +0200 | [diff] [blame] | 289 | """Read up to size uncompressed bytes, while trying to avoid |
| 290 | making multiple reads from the underlying stream. |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 291 | |
| 292 | Returns b"" if the file is at EOF. |
| 293 | """ |
Nadeem Vawda | 37d3ff1 | 2012-08-05 02:19:09 +0200 | [diff] [blame] | 294 | # Usually, read1() calls _fp.read() at most once. However, sometimes |
| 295 | # this does not give enough data for the decompressor to make progress. |
| 296 | # In this case we make multiple reads, to avoid returning b"". |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 297 | self._check_can_read() |
| 298 | if (size == 0 or self._mode == _MODE_READ_EOF or |
| 299 | not self._fill_buffer()): |
| 300 | return b"" |
| 301 | if 0 < size < len(self._buffer): |
| 302 | data = self._buffer[:size] |
| 303 | self._buffer = self._buffer[size:] |
| 304 | else: |
| 305 | data = self._buffer |
| 306 | self._buffer = None |
| 307 | self._pos += len(data) |
| 308 | return data |
| 309 | |
| 310 | def write(self, data): |
| 311 | """Write a bytes object to the file. |
| 312 | |
| 313 | Returns the number of uncompressed bytes written, which is |
| 314 | always len(data). Note that due to buffering, the file on disk |
| 315 | may not reflect the data written until close() is called. |
| 316 | """ |
| 317 | self._check_can_write() |
| 318 | compressed = self._compressor.compress(data) |
| 319 | self._fp.write(compressed) |
| 320 | self._pos += len(data) |
| 321 | return len(data) |
| 322 | |
| 323 | # Rewind the file to the beginning of the data stream. |
| 324 | def _rewind(self): |
| 325 | self._fp.seek(0, 0) |
| 326 | self._mode = _MODE_READ |
| 327 | self._pos = 0 |
| 328 | self._decompressor = LZMADecompressor(**self._init_args) |
| 329 | self._buffer = None |
| 330 | |
| 331 | def seek(self, offset, whence=0): |
| 332 | """Change the file position. |
| 333 | |
| 334 | The new position is specified by offset, relative to the |
| 335 | position indicated by whence. Possible values for whence are: |
| 336 | |
| 337 | 0: start of stream (default): offset must not be negative |
| 338 | 1: current stream position |
| 339 | 2: end of stream; offset must not be positive |
| 340 | |
| 341 | Returns the new file position. |
| 342 | |
| 343 | Note that seeking is emulated, sp depending on the parameters, |
| 344 | this operation may be extremely slow. |
| 345 | """ |
| 346 | self._check_can_seek() |
| 347 | |
| 348 | # Recalculate offset as an absolute file position. |
| 349 | if whence == 0: |
| 350 | pass |
| 351 | elif whence == 1: |
| 352 | offset = self._pos + offset |
| 353 | elif whence == 2: |
| 354 | # Seeking relative to EOF - we need to know the file's size. |
| 355 | if self._size < 0: |
| 356 | self._read_all(return_data=False) |
| 357 | offset = self._size + offset |
| 358 | else: |
| 359 | raise ValueError("Invalid value for whence: {}".format(whence)) |
| 360 | |
| 361 | # Make it so that offset is the number of bytes to skip forward. |
| 362 | if offset < self._pos: |
| 363 | self._rewind() |
| 364 | else: |
| 365 | offset -= self._pos |
| 366 | |
| 367 | # Read and discard data until we reach the desired position. |
| 368 | if self._mode != _MODE_READ_EOF: |
| 369 | self._read_block(offset, return_data=False) |
| 370 | |
| 371 | return self._pos |
| 372 | |
| 373 | def tell(self): |
| 374 | """Return the current file position.""" |
| 375 | self._check_not_closed() |
| 376 | return self._pos |
| 377 | |
| 378 | |
Nadeem Vawda | e860404 | 2012-06-04 23:38:12 +0200 | [diff] [blame] | 379 | def open(filename, mode="rb", *, |
| 380 | format=None, check=-1, preset=None, filters=None, |
| 381 | encoding=None, errors=None, newline=None): |
| 382 | """Open an LZMA-compressed file in binary or text mode. |
| 383 | |
| 384 | filename can be either an actual file name (given as a str or bytes object), |
| 385 | in which case the named file is opened, or it can be an existing file object |
| 386 | to read from or write to. |
| 387 | |
| 388 | The mode argument can be "r", "rb" (default), "w", "wb", "a", or "ab" for |
| 389 | binary mode, or "rt", "wt" or "at" for text mode. |
| 390 | |
| 391 | The format, check, preset and filters arguments specify the compression |
| 392 | settings, as for LZMACompressor, LZMADecompressor and LZMAFile. |
| 393 | |
| 394 | For binary mode, this function is equivalent to the LZMAFile constructor: |
| 395 | LZMAFile(filename, mode, ...). In this case, the encoding, errors and |
| 396 | newline arguments must not be provided. |
| 397 | |
| 398 | For text mode, a LZMAFile object is created, and wrapped in an |
| 399 | io.TextIOWrapper instance with the specified encoding, error handling |
| 400 | behavior, and line ending(s). |
| 401 | |
| 402 | """ |
| 403 | if "t" in mode: |
| 404 | if "b" in mode: |
| 405 | raise ValueError("Invalid mode: %r" % (mode,)) |
| 406 | else: |
| 407 | if encoding is not None: |
| 408 | raise ValueError("Argument 'encoding' not supported in binary mode") |
| 409 | if errors is not None: |
| 410 | raise ValueError("Argument 'errors' not supported in binary mode") |
| 411 | if newline is not None: |
| 412 | raise ValueError("Argument 'newline' not supported in binary mode") |
| 413 | |
| 414 | lz_mode = mode.replace("t", "") |
| 415 | binary_file = LZMAFile(filename, lz_mode, format=format, check=check, |
| 416 | preset=preset, filters=filters) |
| 417 | |
| 418 | if "t" in mode: |
| 419 | return io.TextIOWrapper(binary_file, encoding, errors, newline) |
| 420 | else: |
| 421 | return binary_file |
| 422 | |
| 423 | |
Nadeem Vawda | 3ff069e | 2011-11-30 00:25:06 +0200 | [diff] [blame] | 424 | def compress(data, format=FORMAT_XZ, check=-1, preset=None, filters=None): |
| 425 | """Compress a block of data. |
| 426 | |
| 427 | Refer to LZMACompressor's docstring for a description of the |
| 428 | optional arguments *format*, *check*, *preset* and *filters*. |
| 429 | |
| 430 | For incremental compression, use an LZMACompressor object instead. |
| 431 | """ |
| 432 | comp = LZMACompressor(format, check, preset, filters) |
| 433 | return comp.compress(data) + comp.flush() |
| 434 | |
| 435 | |
| 436 | def decompress(data, format=FORMAT_AUTO, memlimit=None, filters=None): |
| 437 | """Decompress a block of data. |
| 438 | |
| 439 | Refer to LZMADecompressor's docstring for a description of the |
| 440 | optional arguments *format*, *check* and *filters*. |
| 441 | |
| 442 | For incremental decompression, use a LZMADecompressor object instead. |
| 443 | """ |
| 444 | results = [] |
| 445 | while True: |
| 446 | decomp = LZMADecompressor(format, memlimit, filters) |
| 447 | results.append(decomp.decompress(data)) |
| 448 | if not decomp.eof: |
| 449 | raise LZMAError("Compressed data ended before the " |
| 450 | "end-of-stream marker was reached") |
| 451 | if not decomp.unused_data: |
| 452 | return b"".join(results) |
| 453 | # There is unused data left over. Proceed to next stream. |
| 454 | data = decomp.unused_data |