feat: add SequenceSet for sparse deletion tracking with secure erase (Gap 1.7)
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).
This commit is contained in:
Joseph Doherty
@@ -0,0 +1,358 @@
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// Reference: golang/nats-server/server/filestore.go:5267 (removeMsg)
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// golang/nats-server/server/filestore.go:5890 (eraseMsg)
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//
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// Tests verifying:
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// 1. SequenceSet correctly tracks deleted sequences in MsgBlock
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// 2. Tombstones survive MsgBlock recovery (RebuildIndex populates SequenceSet)
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// 3. Secure erase (Delete with secureErase=true) overwrites payload bytes
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// 4. EraseMsg at FileStore level marks the sequence as deleted
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//
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// Go test analogs:
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// TestFileStoreEraseMsgDoesNotLoseTombstones (filestore_test.go:10781)
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// TestFileStoreTombstonesNoFirstSeqRollback (filestore_test.go:10911)
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// TestFileStoreRemoveMsg (filestore_test.go:5267)
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using System.Security.Cryptography;
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using System.Text;
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using NATS.Server.JetStream.Storage;
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namespace NATS.Server.Tests.JetStream.Storage;
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/// <summary>
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/// Tests for SequenceSet-backed deletion tracking and secure erase in MsgBlock.
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/// Reference: golang/nats-server/server/filestore.go eraseMsg / removeMsg.
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/// </summary>
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public sealed class FileStoreTombstoneTrackingTests : IDisposable
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{
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private readonly string _testDir;
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public FileStoreTombstoneTrackingTests()
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{
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_testDir = Path.Combine(Path.GetTempPath(), $"nats-tombstone-tracking-{Guid.NewGuid():N}");
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Directory.CreateDirectory(_testDir);
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}
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public void Dispose()
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{
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if (Directory.Exists(_testDir))
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Directory.Delete(_testDir, recursive: true);
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}
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private string UniqueDir()
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{
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var dir = Path.Combine(_testDir, Guid.NewGuid().ToString("N"));
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Directory.CreateDirectory(dir);
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return dir;
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}
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// -------------------------------------------------------------------------
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// SequenceSet tracking in MsgBlock
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// -------------------------------------------------------------------------
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// Go: removeMsg — after Delete, IsDeleted returns true and DeletedCount == 1
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[Fact]
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public void MsgBlock_Delete_TracksDeletionInSequenceSet()
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{
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var dir = UniqueDir();
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using var block = MsgBlock.Create(0, dir, maxBytes: 1024 * 1024);
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block.Write("a", ReadOnlyMemory<byte>.Empty, "payload"u8.ToArray());
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block.Write("b", ReadOnlyMemory<byte>.Empty, "payload"u8.ToArray());
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block.Write("c", ReadOnlyMemory<byte>.Empty, "payload"u8.ToArray());
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block.Delete(2).ShouldBeTrue();
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block.IsDeleted(2).ShouldBeTrue();
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block.IsDeleted(1).ShouldBeFalse();
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block.IsDeleted(3).ShouldBeFalse();
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block.DeletedCount.ShouldBe(1UL);
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block.MessageCount.ShouldBe(2UL);
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}
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// Multiple deletes tracked correctly — SequenceSet merges contiguous ranges.
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[Fact]
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public void MsgBlock_MultipleDeletes_AllTrackedInSequenceSet()
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{
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var dir = UniqueDir();
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using var block = MsgBlock.Create(0, dir, maxBytes: 1024 * 1024);
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for (var i = 0; i < 10; i++)
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block.Write($"subj.{i}", ReadOnlyMemory<byte>.Empty, "payload"u8.ToArray());
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// Delete seqs 3, 4, 5 (contiguous — SequenceSet will merge into one range).
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block.Delete(3).ShouldBeTrue();
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block.Delete(4).ShouldBeTrue();
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block.Delete(5).ShouldBeTrue();
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block.DeletedCount.ShouldBe(3UL);
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block.MessageCount.ShouldBe(7UL);
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block.IsDeleted(3).ShouldBeTrue();
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block.IsDeleted(4).ShouldBeTrue();
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block.IsDeleted(5).ShouldBeTrue();
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block.IsDeleted(2).ShouldBeFalse();
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block.IsDeleted(6).ShouldBeFalse();
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}
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// -------------------------------------------------------------------------
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// Tombstones survive recovery (RebuildIndex populates SequenceSet)
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// -------------------------------------------------------------------------
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// Go: TestFileStoreTombstonesNoFirstSeqRollback — after restart, deleted seqs still deleted.
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// Reference: filestore.go RebuildIndex reads ebit from block file.
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[Fact]
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public void MsgBlock_Recovery_TombstonesInSequenceSet()
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{
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var dir = UniqueDir();
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// Phase 1: write messages and delete one, then close.
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using (var block = MsgBlock.Create(0, dir, maxBytes: 1024 * 1024))
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{
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block.Write("a", ReadOnlyMemory<byte>.Empty, "one"u8.ToArray());
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block.Write("b", ReadOnlyMemory<byte>.Empty, "two"u8.ToArray());
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block.Write("c", ReadOnlyMemory<byte>.Empty, "three"u8.ToArray());
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block.Delete(2); // marks seq 2 with ebit on disk
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block.Flush();
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}
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// Phase 2: recover from file — SequenceSet must be populated by RebuildIndex.
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using var recovered = MsgBlock.Recover(0, dir);
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recovered.DeletedCount.ShouldBe(1UL);
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recovered.MessageCount.ShouldBe(2UL);
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recovered.IsDeleted(1).ShouldBeFalse();
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recovered.IsDeleted(2).ShouldBeTrue();
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recovered.IsDeleted(3).ShouldBeFalse();
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// Read should return null for deleted seq.
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recovered.Read(2).ShouldBeNull();
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recovered.Read(1).ShouldNotBeNull();
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recovered.Read(3).ShouldNotBeNull();
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}
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// Multiple tombstones survive recovery.
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[Fact]
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public void MsgBlock_Recovery_MultipleDeletedSeqs_AllInSequenceSet()
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{
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var dir = UniqueDir();
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using (var block = MsgBlock.Create(0, dir, maxBytes: 1024 * 1024))
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{
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for (var i = 0; i < 10; i++)
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block.Write($"subj", ReadOnlyMemory<byte>.Empty, "payload"u8.ToArray());
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block.Delete(1);
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block.Delete(3);
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block.Delete(5);
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block.Delete(7);
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block.Delete(9);
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block.Flush();
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}
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using var recovered = MsgBlock.Recover(0, dir);
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recovered.DeletedCount.ShouldBe(5UL);
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recovered.MessageCount.ShouldBe(5UL);
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for (ulong seq = 1; seq <= 9; seq += 2)
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recovered.IsDeleted(seq).ShouldBeTrue($"seq {seq} should be deleted");
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for (ulong seq = 2; seq <= 10; seq += 2)
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recovered.IsDeleted(seq).ShouldBeFalse($"seq {seq} should NOT be deleted");
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}
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// Skip records (WriteSkip) survive recovery and appear in SequenceSet.
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[Fact]
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public void MsgBlock_Recovery_SkipRecordsInSequenceSet()
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{
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var dir = UniqueDir();
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using (var block = MsgBlock.Create(0, dir, maxBytes: 1024 * 1024, firstSequence: 1))
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{
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block.Write("a", ReadOnlyMemory<byte>.Empty, "payload"u8.ToArray()); // seq=1
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block.WriteSkip(2); // tombstone
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block.WriteSkip(3); // tombstone
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block.Write("b", ReadOnlyMemory<byte>.Empty, "payload"u8.ToArray()); // seq=4
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block.Flush();
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}
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using var recovered = MsgBlock.Recover(0, dir);
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// Seqs 2 and 3 are skip records → deleted.
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recovered.IsDeleted(2).ShouldBeTrue();
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recovered.IsDeleted(3).ShouldBeTrue();
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recovered.IsDeleted(1).ShouldBeFalse();
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recovered.IsDeleted(4).ShouldBeFalse();
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recovered.DeletedCount.ShouldBe(2UL);
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recovered.MessageCount.ShouldBe(2UL);
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}
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// -------------------------------------------------------------------------
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// Secure erase — payload bytes are overwritten with random data
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// -------------------------------------------------------------------------
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// Go: eraseMsg (filestore.go:5890) — payload bytes replaced with random bytes.
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[Fact]
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public void MsgBlock_SecureErase_OverwritesPayloadBytes()
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{
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var dir = UniqueDir();
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var original = Encoding.UTF8.GetBytes("this is a secret payload");
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using (var block = MsgBlock.Create(0, dir, maxBytes: 1024 * 1024))
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{
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block.Write("secret", ReadOnlyMemory<byte>.Empty, original);
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// Perform secure erase — overwrites payload bytes in-place on disk.
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block.Delete(1, secureErase: true).ShouldBeTrue();
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block.Flush();
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}
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// Read the raw block file and verify the original payload bytes are gone.
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var blockFile = Path.Combine(dir, "000000.blk");
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var rawBytes = File.ReadAllBytes(blockFile);
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// The payload "this is a secret payload" should no longer appear as a substring.
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var payloadBytes = Encoding.UTF8.GetBytes("this is a secret");
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var rawAsSpan = rawBytes.AsSpan();
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var found = false;
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for (var i = 0; i <= rawBytes.Length - payloadBytes.Length; i++)
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{
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if (rawAsSpan[i..].StartsWith(payloadBytes.AsSpan()))
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{
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found = true;
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break;
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}
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}
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found.ShouldBeFalse("Secret payload bytes should have been overwritten by secure erase");
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}
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// After secure erase, the message appears deleted (returns null on Read).
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[Fact]
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public void MsgBlock_SecureErase_MessageAppearsDeleted()
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{
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var dir = UniqueDir();
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using var block = MsgBlock.Create(0, dir, maxBytes: 1024 * 1024);
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block.Write("sensitive", ReadOnlyMemory<byte>.Empty, "secret data"u8.ToArray());
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block.Write("other", ReadOnlyMemory<byte>.Empty, "normal"u8.ToArray());
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block.Delete(1, secureErase: true).ShouldBeTrue();
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block.IsDeleted(1).ShouldBeTrue();
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block.Read(1).ShouldBeNull();
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block.Read(2).ShouldNotBeNull(); // other message unaffected
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block.DeletedCount.ShouldBe(1UL);
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block.MessageCount.ShouldBe(1UL);
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}
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// Secure erase with secureErase=false is identical to regular delete (no overwrite).
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[Fact]
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public void MsgBlock_Delete_WithSecureEraseFalse_NormalDelete()
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{
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var dir = UniqueDir();
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using var block = MsgBlock.Create(0, dir, maxBytes: 1024 * 1024);
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block.Write("x", ReadOnlyMemory<byte>.Empty, "content"u8.ToArray());
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block.Delete(1, secureErase: false).ShouldBeTrue();
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block.IsDeleted(1).ShouldBeTrue();
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block.Read(1).ShouldBeNull();
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}
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// Double secure erase returns false on second call.
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[Fact]
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public void MsgBlock_SecureErase_DoubleErase_ReturnsFalse()
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{
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var dir = UniqueDir();
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using var block = MsgBlock.Create(0, dir, maxBytes: 1024 * 1024);
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block.Write("x", ReadOnlyMemory<byte>.Empty, "content"u8.ToArray());
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block.Delete(1, secureErase: true).ShouldBeTrue();
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block.Delete(1, secureErase: true).ShouldBeFalse(); // already deleted
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}
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// -------------------------------------------------------------------------
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// DeletedSequences property returns snapshot of SequenceSet
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// -------------------------------------------------------------------------
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// DeletedSequences snapshot contains all deleted seqs (still IReadOnlySet from HashSet copy).
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[Fact]
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public void DeletedSequences_ReturnsCorrectSnapshot()
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{
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var dir = UniqueDir();
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using var block = MsgBlock.Create(0, dir, maxBytes: 1024 * 1024);
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block.Write("a", ReadOnlyMemory<byte>.Empty, "one"u8.ToArray());
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block.Write("b", ReadOnlyMemory<byte>.Empty, "two"u8.ToArray());
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block.Write("c", ReadOnlyMemory<byte>.Empty, "three"u8.ToArray());
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block.Write("d", ReadOnlyMemory<byte>.Empty, "four"u8.ToArray());
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block.Delete(2);
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block.Delete(4);
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var snapshot = block.DeletedSequences;
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snapshot.Count.ShouldBe(2);
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snapshot.ShouldContain(2UL);
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snapshot.ShouldContain(4UL);
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snapshot.ShouldNotContain(1UL);
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snapshot.ShouldNotContain(3UL);
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}
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// -------------------------------------------------------------------------
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// FileStore EraseMsg integration
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// -------------------------------------------------------------------------
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// Go: eraseMsg — after EraseMsg, message is gone and state reflects deletion.
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[Fact]
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public void FileStore_EraseMsg_MessageGoneAfterErase()
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{
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var dir = UniqueDir();
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var opts = new FileStoreOptions { Directory = dir };
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using var store = new FileStore(opts);
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store.StoreMsg("foo", null, "secret"u8.ToArray(), 0);
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store.StoreMsg("foo", null, "normal"u8.ToArray(), 0);
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var state1 = store.State();
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state1.Msgs.ShouldBe(2UL);
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store.EraseMsg(1).ShouldBeTrue();
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var state2 = store.State();
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state2.Msgs.ShouldBe(1UL);
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// Erasing same seq twice returns false.
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store.EraseMsg(1).ShouldBeFalse();
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}
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// Go: TestFileStoreEraseMsgDoesNotLoseTombstones — erase does not disturb other tombstones.
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// Reference: filestore_test.go:10781
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[Fact]
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public void FileStore_EraseMsg_DoesNotLoseTombstones()
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{
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var dir = UniqueDir();
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var opts = new FileStoreOptions { Directory = dir };
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using var store = new FileStore(opts);
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store.StoreMsg("foo", null, [], 0); // seq=1
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store.StoreMsg("foo", null, [], 0); // seq=2 (tombstone)
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store.StoreMsg("foo", null, "secret"u8.ToArray(), 0); // seq=3 (erased)
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store.RemoveMsg(2); // tombstone seq=2
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store.StoreMsg("foo", null, [], 0); // seq=4
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store.EraseMsg(3); // erase seq=3
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var state = store.State();
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state.Msgs.ShouldBe(2UL); // msgs 1 and 4 remain
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state.NumDeleted.ShouldBe(2); // seqs 2 and 3 deleted
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state.Deleted.ShouldNotBeNull();
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state.Deleted!.ShouldContain(2UL);
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state.Deleted.ShouldContain(3UL);
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// Restart — state should be identical.
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store.Dispose();
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using var store2 = new FileStore(opts);
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var after = store2.State();
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after.Msgs.ShouldBe(2UL);
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after.NumDeleted.ShouldBe(2);
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after.Deleted.ShouldNotBeNull();
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after.Deleted!.ShouldContain(2UL);
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after.Deleted.ShouldContain(3UL);
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}
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}
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395
tests/NATS.Server.Tests/JetStream/Storage/SequenceSetTests.cs
Normal file
395
tests/NATS.Server.Tests/JetStream/Storage/SequenceSetTests.cs
Normal file
@@ -0,0 +1,395 @@
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// Reference: golang/nats-server/server/avl/seqset_test.go
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// Tests ported / inspired by:
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// TestSequenceSetBasic → Add_Contains_Count_BasicOperations
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// TestSequenceSetRange → GetEnumerator_ReturnsAscendingOrder
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// TestSequenceSetDelete → Remove_SplitsAndTrimsRanges
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// (range compression) → Add_ContiguousSequences_CompressesToOneRange
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// (binary search) → Contains_BinarySearchCorrectness
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// (boundary) → Add_Remove_AtBoundaries
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using NATS.Server.JetStream.Storage;
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namespace NATS.Server.Tests.JetStream.Storage;
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/// <summary>
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/// Unit tests for <see cref="SequenceSet"/> — the range-compressed sorted set
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/// used to track soft-deleted sequences in JetStream FileStore blocks.
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///
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/// Reference: golang/nats-server/server/avl/seqset_test.go
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/// </summary>
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public sealed class SequenceSetTests
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{
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// -------------------------------------------------------------------------
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// Basic Add / Contains / Count
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// -------------------------------------------------------------------------
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// Go: TestSequenceSetBasic — empty set has zero count
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[Fact]
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public void Count_EmptySet_ReturnsZero()
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{
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var ss = new SequenceSet();
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ss.Count.ShouldBe(0);
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ss.IsEmpty.ShouldBeTrue();
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}
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// Go: TestSequenceSetBasic — single element is found
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[Fact]
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public void Add_SingleSequence_ContainsIt()
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{
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var ss = new SequenceSet();
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ss.Add(42).ShouldBeTrue();
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ss.Contains(42).ShouldBeTrue();
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ss.Count.ShouldBe(1);
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ss.IsEmpty.ShouldBeFalse();
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}
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// Go: duplicate insert returns false (already present)
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[Fact]
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public void Add_DuplicateSequence_ReturnsFalse()
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||||
{
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var ss = new SequenceSet();
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ss.Add(10).ShouldBeTrue();
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ss.Add(10).ShouldBeFalse();
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ss.Count.ShouldBe(1);
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}
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||||
// Go: non-member returns false on Contains
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[Fact]
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public void Contains_NonMember_ReturnsFalse()
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||||
{
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var ss = new SequenceSet();
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ss.Add(5);
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||||
ss.Contains(4).ShouldBeFalse();
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||||
ss.Contains(6).ShouldBeFalse();
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||||
ss.Contains(0).ShouldBeFalse();
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||||
ss.Contains(ulong.MaxValue).ShouldBeFalse();
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||||
}
|
||||
|
||||
// -------------------------------------------------------------------------
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||||
// Range compression
|
||||
// -------------------------------------------------------------------------
|
||||
|
||||
// Adding three contiguous sequences should compress to a single range.
|
||||
// This is the key efficiency property of SequenceSet vs HashSet.
|
||||
[Fact]
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||||
public void Add_ContiguousSequences_CompressesToOneRange()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(1);
|
||||
ss.Add(2);
|
||||
ss.Add(3);
|
||||
|
||||
ss.Count.ShouldBe(3);
|
||||
ss.RangeCount.ShouldBe(1); // single range [1, 3]
|
||||
ss.Contains(1).ShouldBeTrue();
|
||||
ss.Contains(2).ShouldBeTrue();
|
||||
ss.Contains(3).ShouldBeTrue();
|
||||
}
|
||||
|
||||
// Adding in reverse order should still compress.
|
||||
[Fact]
|
||||
public void Add_ContiguousReverse_CompressesToOneRange()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(3);
|
||||
ss.Add(2);
|
||||
ss.Add(1);
|
||||
|
||||
ss.Count.ShouldBe(3);
|
||||
ss.RangeCount.ShouldBe(1); // single range [1, 3]
|
||||
}
|
||||
|
||||
// Two separate gaps should stay as two ranges.
|
||||
[Fact]
|
||||
public void Add_WithGap_TwoRanges()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(1);
|
||||
ss.Add(2);
|
||||
ss.Add(4); // gap at 3
|
||||
ss.Add(5);
|
||||
|
||||
ss.Count.ShouldBe(4);
|
||||
ss.RangeCount.ShouldBe(2); // [1,2] and [4,5]
|
||||
}
|
||||
|
||||
// Filling the gap merges to one range.
|
||||
[Fact]
|
||||
public void Add_FillsGap_MergesToOneRange()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(1);
|
||||
ss.Add(2);
|
||||
ss.Add(4);
|
||||
ss.Add(5);
|
||||
ss.RangeCount.ShouldBe(2);
|
||||
|
||||
// Fill the gap.
|
||||
ss.Add(3);
|
||||
ss.RangeCount.ShouldBe(1); // [1, 5]
|
||||
ss.Count.ShouldBe(5);
|
||||
}
|
||||
|
||||
// Large run of contiguous sequences stays as one range.
|
||||
[Fact]
|
||||
public void Add_LargeContiguousRun_OnlyOneRange()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
for (ulong i = 1; i <= 10_000; i++)
|
||||
ss.Add(i);
|
||||
|
||||
ss.Count.ShouldBe(10_000);
|
||||
ss.RangeCount.ShouldBe(1);
|
||||
}
|
||||
|
||||
// -------------------------------------------------------------------------
|
||||
// Remove / split / trim
|
||||
// -------------------------------------------------------------------------
|
||||
|
||||
// Removing from an empty set returns false.
|
||||
[Fact]
|
||||
public void Remove_EmptySet_ReturnsFalse()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Remove(1).ShouldBeFalse();
|
||||
}
|
||||
|
||||
// Removing a non-member returns false and doesn't change count.
|
||||
[Fact]
|
||||
public void Remove_NonMember_ReturnsFalse()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(5);
|
||||
ss.Remove(4).ShouldBeFalse();
|
||||
ss.Count.ShouldBe(1);
|
||||
}
|
||||
|
||||
// Removing the only element empties the set.
|
||||
[Fact]
|
||||
public void Remove_SingleElement_EmptiesSet()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(7);
|
||||
ss.Remove(7).ShouldBeTrue();
|
||||
ss.Count.ShouldBe(0);
|
||||
ss.IsEmpty.ShouldBeTrue();
|
||||
ss.Contains(7).ShouldBeFalse();
|
||||
}
|
||||
|
||||
// Removing the left edge of a range trims it.
|
||||
[Fact]
|
||||
public void Remove_LeftEdge_TrimsRange()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(1); ss.Add(2); ss.Add(3);
|
||||
ss.RangeCount.ShouldBe(1);
|
||||
|
||||
ss.Remove(1).ShouldBeTrue();
|
||||
ss.Count.ShouldBe(2);
|
||||
ss.Contains(1).ShouldBeFalse();
|
||||
ss.Contains(2).ShouldBeTrue();
|
||||
ss.Contains(3).ShouldBeTrue();
|
||||
ss.RangeCount.ShouldBe(1); // still one range [2, 3]
|
||||
}
|
||||
|
||||
// Removing the right edge of a range trims it.
|
||||
[Fact]
|
||||
public void Remove_RightEdge_TrimsRange()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(1); ss.Add(2); ss.Add(3);
|
||||
|
||||
ss.Remove(3).ShouldBeTrue();
|
||||
ss.Count.ShouldBe(2);
|
||||
ss.Contains(3).ShouldBeFalse();
|
||||
ss.RangeCount.ShouldBe(1); // still [1, 2]
|
||||
}
|
||||
|
||||
// Removing the middle element splits a range into two.
|
||||
[Fact]
|
||||
public void Remove_MiddleElement_SplitsRange()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(1); ss.Add(2); ss.Add(3); ss.Add(4); ss.Add(5);
|
||||
ss.RangeCount.ShouldBe(1);
|
||||
|
||||
ss.Remove(3).ShouldBeTrue();
|
||||
ss.Count.ShouldBe(4);
|
||||
ss.Contains(3).ShouldBeFalse();
|
||||
ss.Contains(1).ShouldBeTrue();
|
||||
ss.Contains(2).ShouldBeTrue();
|
||||
ss.Contains(4).ShouldBeTrue();
|
||||
ss.Contains(5).ShouldBeTrue();
|
||||
ss.RangeCount.ShouldBe(2); // [1,2] and [4,5]
|
||||
}
|
||||
|
||||
// -------------------------------------------------------------------------
|
||||
// Enumeration
|
||||
// -------------------------------------------------------------------------
|
||||
|
||||
// GetEnumerator returns all sequences in ascending order.
|
||||
[Fact]
|
||||
public void GetEnumerator_ReturnsAscendingOrder()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(5); ss.Add(3); ss.Add(1); ss.Add(2); ss.Add(4);
|
||||
|
||||
var list = ss.ToList();
|
||||
list.ShouldBe([1, 2, 3, 4, 5]);
|
||||
}
|
||||
|
||||
// Enumeration over a compressed range expands correctly.
|
||||
[Fact]
|
||||
public void GetEnumerator_CompressedRange_ExpandsAll()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
for (ulong i = 100; i <= 200; i++)
|
||||
ss.Add(i);
|
||||
|
||||
var list = ss.ToList();
|
||||
list.Count.ShouldBe(101);
|
||||
list[0].ShouldBe(100UL);
|
||||
list[^1].ShouldBe(200UL);
|
||||
}
|
||||
|
||||
// Enumeration over multiple disjoint ranges returns all in order.
|
||||
[Fact]
|
||||
public void GetEnumerator_MultipleRanges_AllInOrder()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(10); ss.Add(11);
|
||||
ss.Add(20); ss.Add(21); ss.Add(22);
|
||||
ss.Add(30);
|
||||
|
||||
var list = ss.ToList();
|
||||
list.ShouldBe([10UL, 11UL, 20UL, 21UL, 22UL, 30UL]);
|
||||
}
|
||||
|
||||
// -------------------------------------------------------------------------
|
||||
// Clear
|
||||
// -------------------------------------------------------------------------
|
||||
|
||||
[Fact]
|
||||
public void Clear_RemovesAll()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(1); ss.Add(2); ss.Add(3);
|
||||
ss.Clear();
|
||||
ss.Count.ShouldBe(0);
|
||||
ss.IsEmpty.ShouldBeTrue();
|
||||
ss.Contains(1).ShouldBeFalse();
|
||||
}
|
||||
|
||||
// -------------------------------------------------------------------------
|
||||
// ToHashSet snapshot
|
||||
// -------------------------------------------------------------------------
|
||||
|
||||
[Fact]
|
||||
public void ToHashSet_ReturnsAllElements()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(1); ss.Add(2); ss.Add(5); ss.Add(6); ss.Add(7);
|
||||
|
||||
var hs = ss.ToHashSet();
|
||||
hs.Count.ShouldBe(5);
|
||||
hs.ShouldContain(1UL);
|
||||
hs.ShouldContain(2UL);
|
||||
hs.ShouldContain(5UL);
|
||||
hs.ShouldContain(6UL);
|
||||
hs.ShouldContain(7UL);
|
||||
}
|
||||
|
||||
// -------------------------------------------------------------------------
|
||||
// Binary search correctness — sparse insertions
|
||||
// -------------------------------------------------------------------------
|
||||
|
||||
// Reference: Go seqset_test.go — large number of non-contiguous sequences.
|
||||
[Fact]
|
||||
public void Add_Contains_SparseInsertions_AllFound()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
var expected = new List<ulong>();
|
||||
for (ulong i = 1; i <= 1000; i += 3) // every 3rd: 1, 4, 7, ...
|
||||
{
|
||||
ss.Add(i);
|
||||
expected.Add(i);
|
||||
}
|
||||
|
||||
ss.Count.ShouldBe(expected.Count);
|
||||
|
||||
foreach (var seq in expected)
|
||||
ss.Contains(seq).ShouldBeTrue($"Expected seq {seq} to be present");
|
||||
|
||||
// Non-members should not appear.
|
||||
ss.Contains(2).ShouldBeFalse();
|
||||
ss.Contains(3).ShouldBeFalse();
|
||||
ss.Contains(999).ShouldBeFalse();
|
||||
}
|
||||
|
||||
// -------------------------------------------------------------------------
|
||||
// Boundary conditions
|
||||
// -------------------------------------------------------------------------
|
||||
|
||||
[Fact]
|
||||
public void Add_SequenceZero_Works()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(0).ShouldBeTrue();
|
||||
ss.Contains(0).ShouldBeTrue();
|
||||
ss.Count.ShouldBe(1);
|
||||
}
|
||||
|
||||
[Fact]
|
||||
public void Add_AdjacentToZero_Merges()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
ss.Add(0);
|
||||
ss.Add(1);
|
||||
ss.RangeCount.ShouldBe(1); // [0, 1]
|
||||
ss.Count.ShouldBe(2);
|
||||
}
|
||||
|
||||
[Fact]
|
||||
public void Add_Remove_RoundTrip()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
for (ulong i = 1; i <= 100; i++)
|
||||
ss.Add(i);
|
||||
|
||||
// Remove all odd sequences.
|
||||
for (ulong i = 1; i <= 100; i += 2)
|
||||
ss.Remove(i);
|
||||
|
||||
ss.Count.ShouldBe(50);
|
||||
for (ulong i = 2; i <= 100; i += 2)
|
||||
ss.Contains(i).ShouldBeTrue();
|
||||
for (ulong i = 1; i <= 99; i += 2)
|
||||
ss.Contains(i).ShouldBeFalse();
|
||||
}
|
||||
|
||||
// -------------------------------------------------------------------------
|
||||
// Merging at boundaries of existing ranges (not just single adjacency)
|
||||
// -------------------------------------------------------------------------
|
||||
|
||||
[Fact]
|
||||
public void Add_BridgesMultipleGaps_CorrectState()
|
||||
{
|
||||
var ss = new SequenceSet();
|
||||
// Create three separate ranges: [1,2], [4,5], [7,8]
|
||||
ss.Add(1); ss.Add(2);
|
||||
ss.Add(4); ss.Add(5);
|
||||
ss.Add(7); ss.Add(8);
|
||||
ss.RangeCount.ShouldBe(3);
|
||||
ss.Count.ShouldBe(6);
|
||||
|
||||
// Fill gap between [1,2] and [4,5]: add 3
|
||||
ss.Add(3);
|
||||
ss.RangeCount.ShouldBe(2); // [1,5] and [7,8]
|
||||
ss.Count.ShouldBe(7);
|
||||
|
||||
// Fill gap between [1,5] and [7,8]: add 6
|
||||
ss.Add(6);
|
||||
ss.RangeCount.ShouldBe(1); // [1,8]
|
||||
ss.Count.ShouldBe(8);
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user