Implement Go-parity background flush loop (coalesce 16KB/8ms) in MsgBlock/FileStore,
replace O(n) GetStateAsync with incremental counters, skip PruneExpired/LoadAsync/
PrunePerSubject when not needed, and bypass RAFT for single-replica streams. Fix counter
tracking bugs in RemoveMsg/EraseMsg/TTL expiry and ObjectDisposedException races in
flush loop disposal. FileStore optimizations verified with 3112/3112 JetStream tests
passing; async publish benchmark remains at ~174 msg/s due to E2E protocol path bottleneck.
Replace HashSet<ulong> _deleted in MsgBlock with SequenceSet — a sorted-range
list that compresses contiguous deletions into (Start, End) intervals. Adds
O(log n) Contains/Add via binary search on range count, matching Go's avl.SequenceSet
semantics with a simpler implementation.
- Add SequenceSet.cs: sorted-range compressed set with Add/Remove/Contains/Count/Clear
and IEnumerable<ulong> in ascending order. Binary search for all O(log n) ops.
- Replace HashSet<ulong> _deleted and _skipSequences in MsgBlock with SequenceSet.
- Add secureErase parameter (default false) to MsgBlock.Delete(): when true, payload
bytes are overwritten with RandomNumberGenerator.Fill() before the delete record is
written, making original content unrecoverable on disk.
- Update FileStore.DeleteInBlock() to propagate secureErase flag.
- Update FileStore.EraseMsg() to use secureErase: true via block layer instead of
delegating to RemoveMsg().
- Add SequenceSetTests.cs: 25 tests covering Add, Remove, Contains, Count, range
compression, gap filling, bridge merges, enumeration, boundary values, round-trip.
- Add FileStoreTombstoneTrackingTests.cs: 12 tests covering SequenceSet tracking in
MsgBlock, tombstone persistence through RebuildIndex recovery, secure erase
payload overwrite verification, and FileStore.EraseMsg integration.
Go reference: filestore.go:5267 (removeMsg), filestore.go:5890 (eraseMsg),
avl/seqset.go (SequenceSet).
Add _lastChecksum field and LastChecksum property to MsgBlock tracking
the XxHash64 checksum of the last written record (Go: msgBlock.lchk,
filestore.go:2204). Capture the checksum from the encoded record trailer
on every Write/WriteAt/WriteSkip call. Read-path validation happens
naturally through the existing MessageRecord.Decode checksum check.
Port Go filestore tombstone/deletion tests, consumer state encode/decode,
consumer file store persistence, and message TTL enforcement. Adds
ConsumerStateCodec and ConsumerFileStore implementations.
17 new tests ported from filestore_test.go.
Add MsgBlock write cache (mirrors Go's msgBlock.cache) to serve reads
for recently-written records without disk I/O; cleared on block seal via
RotateBlock. Add HashWheel-based TTL expiry in FileStore (ExpireFromWheel /
RegisterTtl), replacing the O(n) linear scan on every append with an
O(expired) wheel scan. Implement StoreMsg sync method with per-message TTL
override support. Add 10 tests covering cache hits/eviction, wheel expiry,
retention, StoreMsg seq/ts, per-msg TTL, and recovery re-registration.
Implement PurgeEx, Compact, Truncate, FilteredState, SubjectsState,
SubjectsTotals, State, FastState, GetSeqFromTime on FileStore. Add
MsgBlock.IsDeleted, DeletedSequences, EnumerateNonDeleted. Includes
wildcard subject support via SubjectMatch for all filtered operations.
Replace JSONL persistence with real MsgBlock-based block files (.blk).
FileStore now acts as a block manager that creates, seals, and rotates
MsgBlocks while maintaining an in-memory cache for fast reads/queries.
Key changes:
- AppendAsync writes transformed payloads to MsgBlock via WriteAt
- Block rotation occurs when active block reaches size limit
- Recovery scans .blk files and rebuilds in-memory state from records
- Legacy JSONL migration: existing messages.jsonl data is automatically
converted to block files on first open, then JSONL is deleted
- PurgeAsync disposes and deletes all block files
- RewriteBlocks rebuilds blocks from cache (used by trim/restore)
- InvalidDataException propagates during recovery (wrong encryption key)
MsgBlock.WriteAt added to support explicit sequence numbers and timestamps,
needed when rewriting blocks with non-contiguous sequences (after removes).
Tests updated:
- New FileStoreBlockTests.cs with 9 tests for block-specific behavior
- JetStreamFileStoreCompressionEncryptionParityTests updated to read
FSV1 magic from .blk files instead of messages.jsonl
- JetStreamFileStoreDurabilityParityTests updated to verify .blk files
instead of index.manifest.json
All 3,562 tests pass (3,535 passed + 27 skipped, 0 failures).
MsgBlock is the unit of storage in the file store — a single append-only
block file containing sequentially written binary message records. Blocks
are sealed (read-only) when they reach a configurable byte-size limit.
Key features:
- Write: appends MessageRecord-encoded messages with auto-incrementing
sequence numbers and configurable first sequence offset
- Read: positional I/O via RandomAccess.Read for concurrent reader safety
- Delete: soft-delete with on-disk persistence (re-encodes flags byte +
checksum so deletions survive recovery)
- Recovery: rebuilds in-memory index by scanning block file using
MessageRecord.MeasureRecord for record boundary detection
- Thread safety: ReaderWriterLockSlim allows concurrent reads during writes
Also adds MessageRecord.MeasureRecord() — computes a record's byte length
by parsing varint field headers without full decode, needed for sequential
record scanning during block recovery.
Reference: golang/nats-server/server/filestore.go:217-267 (msgBlock struct)
12 tests covering write, read, delete, seal, recovery, concurrency,
and custom sequence offsets.
