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a00d9713e4
Drop the unused gzip code, update comments and add a test for an invalid algorithm. The temporary file is not needed now, so drop that also. Signed-off-by: Simon Glass <sjg@chromium.org>
77 lines
2.1 KiB
Python
77 lines
2.1 KiB
Python
# SPDX-License-Identifier: GPL-2.0+
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# Copyright 2022 Google LLC
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#
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"""Utilities to compress and decompress data"""
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import struct
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import tempfile
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from binman import bintool
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from patman import tools
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LZ4 = bintool.Bintool.create('lz4')
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HAVE_LZ4 = LZ4.is_present()
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LZMA_ALONE = bintool.Bintool.create('lzma_alone')
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HAVE_LZMA_ALONE = LZMA_ALONE.is_present()
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def compress(indata, algo, with_header=True):
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"""Compress some data using a given algorithm
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Note that for lzma this uses an old version of the algorithm, not that
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provided by xz.
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This requires 'lz4' and 'lzma_alone' tools. It also requires an output
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directory to be previously set up, by calling PrepareOutputDir().
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Args:
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indata (bytes): Input data to compress
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algo (str): Algorithm to use ('none', 'lz4' or 'lzma')
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Returns:
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bytes: Compressed data
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"""
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if algo == 'none':
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return indata
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if algo == 'lz4':
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data = LZ4.compress(indata)
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# cbfstool uses a very old version of lzma
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elif algo == 'lzma':
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data = LZMA_ALONE.compress(indata)
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else:
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raise ValueError("Unknown algorithm '%s'" % algo)
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if with_header:
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hdr = struct.pack('<I', len(data))
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data = hdr + data
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return data
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def decompress(indata, algo, with_header=True):
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"""Decompress some data using a given algorithm
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Note that for lzma this uses an old version of the algorithm, not that
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provided by xz.
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This requires 'lz4' and 'lzma_alone' tools. It also requires an output
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directory to be previously set up, by calling PrepareOutputDir().
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Args:
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indata (bytes): Input data to decompress
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algo (str): Algorithm to use ('none', 'lz4' or 'lzma')
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Returns:
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(bytes) Compressed data
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"""
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if algo == 'none':
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return indata
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if with_header:
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data_len = struct.unpack('<I', indata[:4])[0]
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indata = indata[4:4 + data_len]
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if algo == 'lz4':
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data = LZ4.decompress(indata)
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elif algo == 'lzma':
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data = LZMA_ALONE.decompress(indata)
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else:
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raise ValueError("Unknown algorithm '%s'" % algo)
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return data
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