erofs-freebsd-out-tree/tests/TC107-zstd-level22.md

Test Case: zstd Compression Level 22

Test ID: TC107-zstd-level22

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: Medium
Regression: None

Objective

Verify zstd compressed data path with level 22 (maximum) compression.

Preconditions

• EROFS image created with zstd level 22: mkfs.erofs -zzstd,level=22 test.img src/
• Large test files (multi-MB)
• FreeBSD 13.0+ with libzstd

Test Steps

1. Create image with zstd level 22 compression
2. Attach and mount: unit=$(mdconfig -a -t vnode -f test.img); mount -t erofs -o ro /dev/${unit} /mnt
3. Read large files sequentially
4. Test random access
5. Monitor memory usage during decompression

Expected Results

• All files decompress correctly
• Maximum compression ratio for zstd
• Acceptable decompression speed
• Stable memory usage

Verification Method

• Checksums match original files
• Compression ratio > level 15
• Decompression throughput > 100 MB/s
• No memory leaks

Cleanup

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

Notes

Tests feature 59: zstd compressed data path with maximum compression.