erofs-freebsd-out-tree/tests/TC104-deflate-level9.md

Test Case: DEFLATE Compression Level 9

Test ID: TC104-deflate-level9

G5 fixture contract: Use G5-MANUAL-SETUP.md. Its generated paths, source comparisons, structured corruption offsets, and cleanup rules supersede placeholder examples in this file. Category: Compression
Priority: High
Regression: None

Objective

Verify DEFLATE compressed data path with level 9 (maximum) compression.

Preconditions

• EROFS image created with DEFLATE level 9: mkfs.erofs -zdeflate,level=9 test.img src/
• Large test files (1MB+) for compression testing
• FreeBSD 13.0+ with zlib support

Test Steps

1. Create image with DEFLATE level 9 compression
2. Attach and mount: unit=$(mdconfig -a -t vnode -f test.img); mount -t erofs -o ro /dev/${unit} /mnt
3. Read large compressed files sequentially
4. Test random access throughout file
5. Measure decompression performance

Expected Results

• All files decompress correctly
• Best compression ratio among DEFLATE levels
• Slightly slower decompression acceptable
• No data corruption

Verification Method

• Verify checksums match original files
• Compression ratio > level 6
• Decompression throughput > 50 MB/s
• Random access correctness validated

Cleanup

umount /mnt
mdconfig -d -u "${unit}"

Notes

Tests feature 58: DEFLATE compressed data path with maximum compression.