内存优化

NewLife.NovaDb/Core/CompressionCodec.cs

@@ -1,3 +1,4 @@
+using System.Buffers.Binary;
 using System.IO.Compression;
 
 namespace NewLife.NovaDb.Core;
@@ -38,8 +39,15 @@ public Byte[] Compress(Byte[] data)
         output.WriteByte((Byte)Algorithm);
 
         // 写入原始长度（4 字节，用于预分配解压缓冲区）
-        var lenBytes = BitConverter.GetBytes(data.Length);
+#if NETSTANDARD2_1_OR_GREATER || NETCOREAPP3_1_OR_GREATER
+        Span<Byte> lenBytes = stackalloc Byte[4];
+        BinaryPrimitives.WriteInt32LittleEndian(lenBytes, data.Length);
+        output.Write(lenBytes);
+#else
+        var lenBytes = new Byte[4];
+        BinaryPrimitives.WriteInt32LittleEndian(lenBytes, data.Length);
         output.Write(lenBytes, 0, 4);
+#endif
 
         // 压缩
         using (var compressStream = CreateCompressStream(output))

NewLife.NovaDb/Core/MetadataLock.cs

@@ -1,6 +1,4 @@
-using System.Threading;
-
-namespace NewLife.NovaDb.Core;
+namespace NewLife.NovaDb.Core;
 
 /// <summary>元数据读写锁，用于 DDL 与 DML/SELECT 的并发控制</summary>
 /// <remarks>

NewLife.NovaDb/Core/NovaMetrics.cs

@@ -1,6 +1,4 @@
-using System.Threading;
-
-namespace NewLife.NovaDb.Core;
+namespace NewLife.NovaDb.Core;
 
 /// <summary>NovaDb 运行时指标</summary>
 /// <remarks>所有计数器均为线程安全，支持多线程并发递增</remarks>

NewLife.NovaDb/Core/SlowQueryLog.cs

@@ -1,5 +1,4 @@
-using System.Collections.Concurrent;
-using NewLife.Log;
+using NewLife.Log;
 
 namespace NewLife.NovaDb.Core;
 

NewLife.NovaDb/Engine/ColdIndexDirectory.cs

@@ -1,6 +1,4 @@
-using System.Linq;
-
-namespace NewLife.NovaDb.Engine;
+namespace NewLife.NovaDb.Engine;
 
 /// <summary>冷段目录项（稀疏索引）</summary>
 public class ColdDirectoryEntry

NewLife.NovaDb/Engine/Flux/FluxEngine.Persist.cs

@@ -1,4 +1,7 @@
+using System.Buffers;
+using System.Buffers.Binary;
 using System.Text;
+using NewLife.NovaDb.Utilities;
 using NewLife.Security;
 
 namespace NewLife.NovaDb.Engine.Flux;
@@ -22,6 +25,7 @@ public partial class FluxEngine
     private const Byte RecordType_FluxAppend = 1;
     private const Byte RecordType_FluxPurge = 2;
 
+    private static readonly Encoding _encoding = Encoding.UTF8;
     private static readonly Byte[] FluxLogMagic = [(Byte)'N', (Byte)'F', (Byte)'L', (Byte)'G'];
     private const Int32 FluxLogHeaderSize = 32;
 
@@ -63,12 +67,24 @@ private void OpenFluxLog()
     /// <summary>写入文件头</summary>
     private void WriteFluxLogHeader()
     {
+#if NETSTANDARD2_1_OR_GREATER || NETCOREAPP3_1_OR_GREATER
+        Span<Byte> header = stackalloc Byte[FluxLogHeaderSize];
+        FluxLogMagic.AsSpan().CopyTo(header.Slice(0, 4));
+#else
         var header = new Byte[FluxLogHeaderSize];
-        Array.Copy(FluxLogMagic, 0, header, 0, 4);
+        FluxLogMagic.AsSpan().CopyTo(header.AsSpan(0, 4));
+#endif
+
         header[4] = 1; // Version
 
         _fluxLogStream!.Position = 0;
+
+#if NETSTANDARD2_1_OR_GREATER || NETCOREAPP3_1_OR_GREATER
+        _fluxLogStream.Write(header);
+#else
         _fluxLogStream.Write(header, 0, header.Length);
+#endif
+
         _fluxLogStream.Flush();
     }
 
@@ -78,9 +94,13 @@ private void ValidateFluxLogHeader()
         if (_fluxLogStream!.Length < FluxLogHeaderSize) return;
 
         _fluxLogStream.Position = 0;
+#if NETSTANDARD2_1_OR_GREATER || NETCOREAPP3_1_OR_GREATER
+        Span<Byte> header = stackalloc Byte[FluxLogHeaderSize];
+        if (_fluxLogStream.Read(header) < FluxLogHeaderSize) return;
+#else
         var header = new Byte[FluxLogHeaderSize];
         if (_fluxLogStream.Read(header, 0, header.Length) < FluxLogHeaderSize) return;
-
+#endif
         if (header[0] != FluxLogMagic[0] || header[1] != FluxLogMagic[1] ||
             header[2] != FluxLogMagic[2] || header[3] != FluxLogMagic[3])
             throw new InvalidOperationException("Invalid Flux log file header");
@@ -96,31 +116,38 @@ private void PersistFluxAppend(FluxEntry entry)
     {
         if (_fluxLogStream == null) return;
 
-        using var ms = new MemoryStream();
-        using var bw = new BinaryWriter(ms);
+        // 初始容量给个经验值：头部(8+4) + fields/tags 数量 + 少量字符串
+        // 不够会自动扩容（扩容也不会产生 GC 垃圾，走 ArrayPool）
+        var w = new PooledBufferWriter(initialCapacity: 1024);
+        try
+        {
+            w.WriteInt64(entry.Timestamp);
+            w.WriteInt32(entry.SequenceId);
 
-        bw.Write(entry.Timestamp);
-        bw.Write(entry.SequenceId);
+            // Fields
+            var fields = entry.Fields;
+            w.WriteInt32(fields.Count);
+            foreach (var kv in fields)
+            {
+                WriteString(ref w, kv.Key);
+                WriteFieldValue(ref w, kv.Value);
+            }
 
-        // Fields
-        var fields = entry.Fields;
-        bw.Write(fields.Count);
-        foreach (var kv in fields)
-        {
-            WriteString(bw, kv.Key);
-            WriteFieldValue(bw, kv.Value);
-        }
+            // Tags
+            var tags = entry.Tags;
+            w.WriteInt32(tags.Count);
+            foreach (var kv in tags)
+            {
+                WriteString(ref w, kv.Key);
+                WriteString(ref w, kv.Value);
+            }
 
-        // Tags
-        var tags = entry.Tags;
-        bw.Write(tags.Count);
-        foreach (var kv in tags)
+            WriteFluxRecord(1, w.Buffer, 0, w.WrittenCount);
+        }
+        finally
         {
-            WriteString(bw, kv.Key);
-            WriteString(bw, kv.Value);
+            w.Dispose();
         }
-
-        WriteFluxRecord(RecordType_FluxAppend, ms.ToArray());
     }
 
     /// <summary>持久化 Purge 记录（删除过期分区）</summary>
@@ -129,88 +156,123 @@ private void PersistFluxPurge(String cutoffKey)
     {
         if (_fluxLogStream == null) return;
 
-        var data = Encoding.UTF8.GetBytes(cutoffKey);
-        WriteFluxRecord(RecordType_FluxPurge, data);
+        using var pooledBytes = _encoding.GetPooledEncodedBytes(cutoffKey);
+        WriteFluxRecord(RecordType_FluxPurge, pooledBytes.Buffer, 0, pooledBytes.Length);
     }
 
-    /// <summary>写入一条记录</summary>
-    private void WriteFluxRecord(Byte recordType, Byte[] data)
+    private void WriteFluxRecord(Byte recordType, Byte[] data, Int32 offset, Int32 count)
     {
-        var recordLength = 1 + data.Length + 4;
+        // recordLength: [recordType(1)] + [payload(count)] + [crc32(4)]
+        var recordLength = checked(1 + count + 4);
+        var totalLength = checked(4 + recordLength); // length prefix + record
+
+        Byte[]? rented = null;
+        var buffer = totalLength <= 1024
+            ? stackalloc Byte[totalLength]
+            : (rented = ArrayPool<Byte>.Shared.Rent(totalLength)).AsSpan(0, totalLength);
 
-        using var ms = new MemoryStream(4 + recordLength);
-        using var bw = new BinaryWriter(ms);
+        try
+        {
+            // 写 recordLength (Little Endian)
+            BinaryPrimitives.WriteInt32LittleEndian(buffer.Slice(0, 4), recordLength);
 
-        bw.Write(recordLength);
-        bw.Write(recordType);
-        bw.Write(data);
+            // 写 recordType
+            buffer[4] = recordType;
 
-        // CRC32 校验
-        var checkBuffer = new Byte[1 + data.Length];
-        checkBuffer[0] = recordType;
-        Array.Copy(data, 0, checkBuffer, 1, data.Length);
-        var checksum = Crc32.Compute(checkBuffer, 0, checkBuffer.Length);
-        bw.Write(checksum);
+            // 写 payload
+            data.AsSpan(offset, count).CopyTo(buffer.Slice(5, count));
 
-        var buffer = ms.ToArray();
-        _fluxLogStream!.Position = _fluxLogStream.Length;
-        _fluxLogStream.Write(buffer, 0, buffer.Length);
-        _fluxLogStream.Flush();
+            // 计算 CRC32：覆盖 [recordType + payload]，也就是 buffer[4..(5+count))
+            var checksum = Crc32.Compute(buffer.Slice(4, 1 + count));
+
+            // 写 CRC32 (Little Endian)
+            BinaryPrimitives.WriteUInt32LittleEndian(buffer.Slice(5 + count, 4), checksum);
+
+            // 写入到底层流
+            _fluxLogStream!.Seek(0, SeekOrigin.End);
+#if NETSTANDARD2_1_OR_GREATER || NETCOREAPP3_1_OR_GREATER
+            _fluxLogStream.Write(buffer); // .NET Standard 2.1+ 有 Span 重载；低版本见下面兼容写法
+#else
+            if (rented is not null)
+            {
+                _fluxLogStream.Write(rented, 0, totalLength);
+            }
+            else
+            {
+                var tempBuffer = ArrayPool<Byte>.Shared.Rent(totalLength);
+                try
+                {
+                    buffer.CopyTo(tempBuffer.AsSpan(0, totalLength));
+                    _fluxLogStream.Write(tempBuffer, 0, totalLength);
+                }
+                finally
+                {
+                    ArrayPool<Byte>.Shared.Return(tempBuffer);
+                }
+            }
+#endif
+            _fluxLogStream.Flush();
+        }
+        finally
+        {
+            if (rented is not null)
+                ArrayPool<Byte>.Shared.Return(rented);
+        }
     }
 
     #endregion
 
     #region 字段序列化
 
     /// <summary>写入 UTF-8 字符串（长度前缀）</summary>
-    private static void WriteString(BinaryWriter bw, String value)
+    private static void WriteString(ref PooledBufferWriter w, String value)
     {
-        var bytes = Encoding.UTF8.GetBytes(value);
-        bw.Write(bytes.Length);
-        bw.Write(bytes);
+        using var bytes = value.ToPooledUtf8Bytes();
+        w.WriteInt32(bytes.Length);
+        w.WriteBytes(bytes.AsSpan());
     }
 
     /// <summary>读取 UTF-8 字符串（长度前缀）</summary>
     private static String ReadString(BinaryReader br)
     {
         var len = br.ReadInt32();
         var bytes = br.ReadBytes(len);
-        return Encoding.UTF8.GetString(bytes);
+        return _encoding.GetString(bytes);
     }
 
     /// <summary>写入字段值（带类型标签）</summary>
-    private static void WriteFieldValue(BinaryWriter bw, Object? value)
+    private static void WriteFieldValue(ref PooledBufferWriter w, Object? value)
     {
         switch (value)
         {
             case null:
-                bw.Write(TypeTag_Null);
+                w.WriteByte(TypeTag_Null);
                 break;
             case Int32 i:
-                bw.Write(TypeTag_Int32);
-                bw.Write(i);
+                w.WriteByte(TypeTag_Int32);
+                w.WriteInt32(i);
                 break;
             case Int64 l:
-                bw.Write(TypeTag_Int64);
-                bw.Write(l);
+                w.WriteByte(TypeTag_Int64);
+                w.WriteInt64(l);
                 break;
             case Double d:
-                bw.Write(TypeTag_Double);
-                bw.Write(d);
+                w.WriteByte(TypeTag_Double);
+                w.WriteDouble(d);
                 break;
             case Boolean b:
-                bw.Write(TypeTag_Boolean);
-                bw.Write(b);
+                w.WriteByte(TypeTag_Boolean);
+                w.WriteBool(b);
                 break;
             case Byte[] bytes:
-                bw.Write(TypeTag_Bytes);
-                bw.Write(bytes.Length);
-                bw.Write(bytes);
+                w.WriteByte(TypeTag_Bytes);
+                w.WriteInt32(bytes.Length);
+                w.WriteBytes(bytes);
                 break;
             default:
                 // 其他类型统一转为 String
-                bw.Write(TypeTag_String);
-                WriteString(bw, value.ToString() ?? "");
+                w.WriteByte(TypeTag_String);
+                WriteString(ref w, value.ToString() ?? String.Empty);
                 break;
         }
     }
@@ -324,7 +386,7 @@ private void ReplayFluxAppend(Byte[] body, Int32 offset, Int32 dataLength)
     /// <summary>回放 Purge 记录</summary>
     private void ReplayFluxPurge(Byte[] body, Int32 offset, Int32 dataLength)
     {
-        var cutoffKey = Encoding.UTF8.GetString(body, offset, dataLength);
+        var cutoffKey = _encoding.GetString(body, offset, dataLength);
 
         var toRemove = new List<String>();
         foreach (var key in _partitions.Keys)

NewLife.NovaDb/Engine/Flux/FluxEntry.cs

@@ -30,7 +30,7 @@ public static (Int64 timestamp, Int32 seq) ParseMessageId(String id)
         if (dashIndex < 0)
             throw new FormatException($"Invalid message ID format: '{id}'");
 
-#if NETSTANDARD2_1_OR_GREATER
+#if NETSTANDARD2_1_OR_GREATER || NETCOREAPP3_1_OR_GREATER
         var timestamp = Int64.Parse(id.AsSpan(0, dashIndex));
         var seq = Int32.Parse(id.AsSpan(dashIndex + 1));
         return (timestamp, seq);

NewLife.NovaDb/Engine/Flux/MessageId.cs

@@ -51,7 +51,7 @@ public static MessageId Parse(String value)
         if (dashIndex < 0)
             throw new FormatException($"Invalid MessageId format: '{value}'");
 
-#if NETSTANDARD2_1_OR_GREATER
+#if NETSTANDARD2_1_OR_GREATER || NETCOREAPP3_1_OR_GREATER
         var timestamp = Int64.Parse(value.AsSpan(0, dashIndex));
         var sequence = Int32.Parse(value.AsSpan(dashIndex + 1));
         return new MessageId(timestamp, sequence);
@@ -93,7 +93,7 @@ public Boolean Equals(MessageId? other)
     /// <returns>哈希码</returns>
     public override Int32 GetHashCode()
     {
-#if NETSTANDARD2_1_OR_GREATER
+#if NETSTANDARD2_1_OR_GREATER || NETCOREAPP3_1_OR_GREATER
         return HashCode.Combine(Timestamp, Sequence);
 #else
         unchecked

NewLife.NovaDb/Engine/KV/KvEntry.cs

@@ -1,4 +1,6 @@
-namespace NewLife.NovaDb.Engine.KV;
+using System.Runtime.CompilerServices;
+
+namespace NewLife.NovaDb.Engine.KV;
 
 /// <summary>KV 内存索引项。Bitcask 模型仅索引驻留内存，值保留在磁盘按需读取</summary>
 /// <remarks>
@@ -17,5 +19,6 @@ public struct KvEntry
     public DateTime ExpiresAt;
 
     /// <summary>检查是否已过期</summary>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public readonly Boolean IsExpired() => ExpiresAt < DateTime.MaxValue && DateTime.UtcNow >= ExpiresAt;
 }