task5(batch39): add reply parsing and consumer identity helpers

dotnet/src/ZB.MOM.NatsNet.Server/JetStream/NatsConsumer.Dispatch.ReplyParsing.cs

@@ -0,0 +1,118 @@
+namespace ZB.MOM.NatsNet.Server;
+
+internal sealed partial class NatsConsumer
+{
+    internal static (ulong StreamSequence, ulong DeliverySequence, ulong DeliveryCount, long Timestamp, ulong Pending) ReplyInfo(string subject)
+    {
+        if (string.IsNullOrWhiteSpace(subject))
+            return (0, 0, 0, 0, 0);
+
+        var tokens = subject.Split('.', StringSplitOptions.RemoveEmptyEntries);
+        if (tokens.Length < 9 || !string.Equals(tokens[0], "$JS", StringComparison.Ordinal) || !string.Equals(tokens[1], "ACK", StringComparison.Ordinal))
+            return (0, 0, 0, 0, 0);
+
+        var deliveryCount = (ulong)Math.Max(0, ParseAckReplyNum(tokens[4]));
+        var streamSequence = (ulong)Math.Max(0, ParseAckReplyNum(tokens[5]));
+        var deliverySequence = (ulong)Math.Max(0, ParseAckReplyNum(tokens[6]));
+        var timestamp = ParseAckReplyNum(tokens[7]);
+        var pending = (ulong)Math.Max(0, ParseAckReplyNum(tokens[8]));
+
+        return (streamSequence, deliverySequence, deliveryCount, timestamp, pending);
+    }
+
+    internal ulong NextSeq()
+    {
+        _mu.EnterReadLock();
+        try
+        {
+            return _state.Delivered.Consumer + 1;
+        }
+        finally
+        {
+            _mu.ExitReadLock();
+        }
+    }
+
+    internal bool HasSkipListPending() => false;
+
+    internal void SelectStartingSeqNo()
+    {
+        _mu.EnterWriteLock();
+        try
+        {
+            var start = Config.OptStartSeq > 0 ? Config.OptStartSeq : 1UL;
+            _state.Delivered = new SequencePair { Consumer = 1, Stream = start };
+            _state.AckFloor = new SequencePair { Consumer = 0, Stream = start > 0 ? start - 1 : 0 };
+            _npc = 0;
+            _npf = _state.AckFloor.Stream;
+        }
+        finally
+        {
+            _mu.ExitWriteLock();
+        }
+    }
+
+    internal static bool IsDurableConsumer(ConsumerConfig? config) =>
+        config is not null && !string.IsNullOrWhiteSpace(config.Durable);
+
+    internal bool IsDurable() => !string.IsNullOrWhiteSpace(Config.Durable);
+
+    internal string String() => Name;
+
+    internal static string CreateConsumerName() => Guid.NewGuid().ToString("N")[..12];
+
+    internal NatsStream? GetStream()
+    {
+        _mu.EnterReadLock();
+        try
+        {
+            return _streamRef;
+        }
+        finally
+        {
+            _mu.ExitReadLock();
+        }
+    }
+
+    internal string StreamName() => GetStream()?.Name ?? string.Empty;
+
+    internal bool IsActive()
+    {
+        _mu.EnterReadLock();
+        try
+        {
+            return !_closed && (_hasLocalDeliveryInterest || IsPullMode());
+        }
+        finally
+        {
+            _mu.ExitReadLock();
+        }
+    }
+
+    internal bool HasNoLocalInterest() => !HasDeliveryInterest(localInterest: true);
+
+    internal void Purge()
+    {
+        _mu.EnterWriteLock();
+        try
+        {
+            _state.Pending?.Clear();
+            _state.Redelivered?.Clear();
+            _redeliveryQueue.Clear();
+            _redeliveryIndex.Clear();
+            _npc = 0;
+        }
+        finally
+        {
+            _mu.ExitWriteLock();
+        }
+    }
+
+    internal static Timer? StopAndClearTimer(Timer? timer)
+    {
+        timer?.Dispose();
+        return null;
+    }
+
+    internal void DeleteWithoutAdvisory() => Stop();
+}

dotnet/src/ZB.MOM.NatsNet.Server/JetStream/NatsStream.Consumers.cs

@@ -227,6 +227,20 @@ internal sealed partial class NatsStream
         }
     }
 
+    internal Exception? DeleteConsumer(NatsConsumer consumer)
+    {
+        ArgumentNullException.ThrowIfNull(consumer);
+
+        lock (_consumersSync)
+        {
+            _consumers.Remove(consumer.Name);
+            _consumerList.RemoveAll(c => ReferenceEquals(c, consumer));
+        }
+
+        consumer.DeleteWithoutAdvisory();
+        return null;
+    }
+
     internal void SwapSigSubs(NatsConsumer consumer, string[]? newFilters)
     {
         _ = consumer;