129 lines
4.2 KiB
Python
129 lines
4.2 KiB
Python
# SPDX-License-Identifier: GPL-2.0+
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# Copyright 2022 Google LLC
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#
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"""Bintool implementation for lz4
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lz4 allows compression and decompression of files.
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Documentation is available via::
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man lz4
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Here is the help:
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*** LZ4 command line interface 64-bits v1.9.3, by Yann Collet ***
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Usage :
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lz4 [arg] [input] [output]
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input : a filename
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with no FILE, or when FILE is - or stdin, read standard input
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Arguments :
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-1 : Fast compression (default)
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-9 : High compression
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-d : decompression (default for .lz4 extension)
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-z : force compression
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-D FILE: use FILE as dictionary
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-f : overwrite output without prompting
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-k : preserve source files(s) (default)
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--rm : remove source file(s) after successful de/compression
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-h/-H : display help/long help and exit
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Advanced arguments :
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-V : display Version number and exit
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-v : verbose mode
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-q : suppress warnings; specify twice to suppress errors too
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-c : force write to standard output, even if it is the console
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-t : test compressed file integrity
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-m : multiple input files (implies automatic output filenames)
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-r : operate recursively on directories (sets also -m)
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-l : compress using Legacy format (Linux kernel compression)
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-B# : cut file into blocks of size # bytes [32+]
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or predefined block size [4-7] (default: 7)
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-BI : Block Independence (default)
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-BD : Block dependency (improves compression ratio)
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-BX : enable block checksum (default:disabled)
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--no-frame-crc : disable stream checksum (default:enabled)
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--content-size : compressed frame includes original size (default:not present)
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--list FILE : lists information about .lz4 files (useful for files compressed
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with --content-size flag)
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--[no-]sparse : sparse mode (default:enabled on file, disabled on stdout)
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--favor-decSpeed: compressed files decompress faster, but are less compressed
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--fast[=#]: switch to ultra fast compression level (default: 1)
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--best : same as -12
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Benchmark arguments :
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-b# : benchmark file(s), using # compression level (default : 1)
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-e# : test all compression levels from -bX to # (default : 1)
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-i# : minimum evaluation time in seconds (default : 3s)
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"""
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import re
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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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# pylint: disable=C0103
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class Bintoollz4(bintool.Bintool):
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"""Compression/decompression using the LZ4 algorithm
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This bintool supports running `lz4` to compress and decompress data, as
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used by binman.
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It is also possible to fetch the tool, which uses `apt` to install it.
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Documentation is available via::
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man lz4
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"""
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def __init__(self, name):
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super().__init__(name, 'lz4 compression', r'.* (v[0-9.]*),.*')
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def compress(self, indata):
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"""Compress data with lz4
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Args:
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indata (bytes): Data to compress
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Returns:
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bytes: Compressed data
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"""
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with tempfile.NamedTemporaryFile(prefix='comp.tmp',
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dir=tools.get_output_dir()) as tmp:
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tools.write_file(tmp.name, indata)
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args = ['--no-frame-crc', '-B4', '-5', '-c', tmp.name]
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return self.run_cmd(*args, binary=True)
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def decompress(self, indata):
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"""Decompress data with lz4
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Args:
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indata (bytes): Data to decompress
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Returns:
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bytes: Decompressed data
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"""
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with tempfile.NamedTemporaryFile(prefix='decomp.tmp',
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dir=tools.get_output_dir()) as inf:
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tools.write_file(inf.name, indata)
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args = ['-cd', inf.name]
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return self.run_cmd(*args, binary=True)
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def fetch(self, method):
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"""Fetch handler for lz4
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This installs the lz4 package using the apt utility.
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Args:
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method (FETCH_...): Method to use
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Returns:
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True if the file was fetched and now installed, None if a method
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other than FETCH_BIN was requested
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Raises:
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Valuerror: Fetching could not be completed
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"""
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if method != bintool.FETCH_BIN:
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return None
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return self.apt_install('lz4')
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