Decompress a compressed tar once before reading it - #241
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A compressed stream seeks backwards by decompressing again from its start. The tar seeker reads each search's matches in archive order, but artifacts search one after another, so a compressed tar read in place rewinds over and over. On a 5.36 GB Android extraction with ALEAPP that was 56 rewinds and 220 GB decompressed as a .tar.gz, 347 s against 33 s for the plain tar, and about two hours projected as a .tar.xz. FileSeekerTar now decompresses a gzip, bzip2, xz or (on Python 3.14) zstd tar once into the report folder and reads the plain copy. cleanup() deletes the copy, and so does exit if a run never reaches cleanup(). When the copy cannot be written the seeker logs why and reads the archive in place as before. The run log records how long the step took, and the README says the run needs free space for the uncompressed tar. test_seeker_tar_compressed.py covers every codec this Python can write, a plain tar, a copy that cannot be written and a truncated archive. It is the same file in all five cores. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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A compressed tar is now decompressed once into the report folder and read as a plain tar. Read in place, it decompressed again from the start every time the seeker went back to an earlier file.
On a 5.36 GB Android extraction with ALEAPP, all 59 LAVA tables identical to the plain tar:
.tar: 31 s.tar.gz: 347 s before (56 rewinds, 220 GB decompressed), 40 s now.tar.xz: about two hours projected before, 221 s nowThe copy is deleted when the run ends, or at exit if the run never gets there. If it cannot be written, the seeker logs why and reads the archive in place as before. The README says the run needs free space for the uncompressed tar.
test_seeker_tar_compressed.pyis the same file in all five cores.🤖 Generated with Claude Code