erofs-freebsd-out-tree/tests/TC106-zstd-level15.md

Test Case: zstd Compression Level 15

Test ID: TC106-zstd-level15

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 zstd compressed data path with level 15 (high) compression.

Preconditions

• EROFS image created with zstd level 15: mkfs.erofs -zzstd,level=15 test.img src/
• Large test files for compression testing
• FreeBSD 13.0+ with libzstd

Test Steps

1. Create image with zstd level 15 compression
2. Attach and mount: unit=$(mdconfig -a -t vnode -f test.img); mount -t erofs -o ro /dev/${unit} /mnt
3. Read all test files
4. Verify content integrity
5. Test partial reads

Expected Results

• All files decompress correctly
• Better compression than level 1
• Decompression still fast
• No memory issues

Verification Method

• All checksums match
• Compression ratio > zstd level 1
• Decompression works for all files
• Random access validated

Cleanup

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

Notes

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