# Phase 7 gate — mongo-lite vs MongoDB 8.3.7, 1g dataset / ~16k docs
# Ratio < 1.0 = mongo-lite faster. Reproduce: bash tests/e2e/compare-run.sh 1g 16k
# All five roadmap items plus the three durability/correctness fixes below.
# Compare: tests/e2e/results/phase6.txt (same code, broken commit path) and
# tests/e2e/results/phase1.txt (pre-tree baseline).

benchmark                                   mongo-lite              mongodb                 ratio
insertOne (sequential) ×200                 0.19 ms                 4.9 ms                  0.0x
bulk insert throughput                      753.5 MB/s              704.6 MB/s              1.1x
docs loaded                                 65,536                  65,536                  1.0x
createIndex({k: 1})                         75.7 ms                 75.5 ms                 1.0x
countDocuments({})                          3.4 ms                  11.2 ms                 0.3x
findOne({_id: <ObjectId>})                  0.61 ms                 0.63 ms                 1.0x
findOne({k: 500}) (indexed)                 0.57 ms                 2.3 ms                  0.2x
find({p: {$gte,$lt}}).count() (scan)        13.5 ms                 14.6 ms                 0.9x
find({}).sort({_id:-1}).limit(20)           2.3 ms                  2.5 ms                  0.9x
find({}, {proj}).limit(1000)                3.7 ms                  4.4 ms                  0.8x
aggregate $group by k                       8.3 ms                  15.1 ms                 0.5x
updateOne({_id}) ×50                        0.16 ms                 0.20 ms                 0.8x
updateMany({k: 7}, {$inc})                  2.0 ms                  5.3 ms                  0.4x
deleteOne({_id}) + insertOne                0.58 ms                 5.0 ms                  0.1x
node client RSS                             153 MB                  154 MB                  1.0x
server RSS                                  546 MB                  1424 MB
kill -9 reopen                              0.8s                    1.3s
db on disk                                  97MB                    95MB

# No regression from the fixes. Against phase6 (which measured a commit path
# that mostly skipped its fsync): bulk 739 -> 753.5 MB/s, insertOne 0.20 ->
# 0.19 ms, updateMany 1.9 -> 2.0 ms, RSS 547 -> 546 MB, disk and reopen
# unchanged — all within run noise. The real fsync per commit does not show
# here because this benchmark is single-connection and writes through large
# insertMany batches, so one commit is amortized over the whole batch.
#
# What phase6 could not have measured, because the crash pair did not pass:
#   - kill -9 durability: 13 runs over 1/2/8 connections, 1200 acknowledged
#     inserts each, zero lost.
#   - concurrent durable writes (sequential insertOne per client):
#     1 client 7.1k docs/s | 8 clients 15.0k | 32 clients 21.8k.
#
# Fixes in this commit (each reproduced before it was fixed):
#   1. Engine.commit compared log.end_pos with the last committed position to
#      decide a writer was already covered. Under block framing an append
#      leaves its bytes in the log's open block without moving end_pos, so
#      after the first commit every later write command returned without
#      sealing or syncing. A no-op deleteMany followed by insertMany(50) was
#      acknowledged with the file still 16 bytes (header only) and lost
#      everything on kill -9. Coverage is now by sequence number.
#   2. Compaction read new_end_pos before new_log.sync(), but the sync is
#      what seals the open block and moves end_pos past it, so later appends
#      overwrote the compacted file's last block. e2e6's phase 2 ended with
#      1000 documents in memory and 996 after a graceful restart.
#   3. cmd_find returned without a reply on a missing namespace, so find on
#      an unknown collection reached the driver as a malformed response
#      ("MongoServerError: n/a") instead of an empty cursor.
#
# Verification: unit suite in ReleaseFast/ReleaseSafe/Debug, the split fuzzer
# (src/fuzz_split.zig), all six e2e suites (e2e6 72/72), and the kill -9
# crash pair — none of which passed before these fixes.