Removed Old BufferReader (#2025)

* Unified Readers * Removed PositionOf from reader * Added tests for CopyTo * reacted to changes to ReadOnlyBuffer * Renamed CopyTo to Peek
dotnet · Jan 9, 2018 · 1fecfe7 · 1fecfe7
1 parent 00bc61f
commit 1fecfe7
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Showing 12 changed files with 373 additions and 474 deletions.
diff --git a/src/System.Buffers.Experimental/System/Buffers/BufferReader_binary.cs b/src/System.Buffers.Experimental/System/Buffers/BufferReader_binary.cs
@@ -0,0 +1,49 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.Buffers.Binary;
+using System.Collections.Sequences;
+
+namespace System.Buffers
+{
+    public static partial class BufferReaderExtensions
+    {
+        public static bool TryRead<TSequence>(ref BufferReader<TSequence> reader, out int value, bool littleEndian = false)
+            where TSequence : ISequence<ReadOnlyMemory<byte>>
+        {
+            var unread = reader.UnreadSegment;
+            if (littleEndian)
+            {
+                if (BinaryPrimitives.TryReadInt32LittleEndian(unread, out value))
+                {
+                    reader.Skip(sizeof(int));
+                    return true;
+                }
+            }
+            else if (BinaryPrimitives.TryReadInt32BigEndian(unread, out value))
+            {
+                reader.Skip(sizeof(int));
+                return true;
+            }
+
+            Span<byte> tempSpan = stackalloc byte[4];
+            var copied = BufferReader.Peek(reader, tempSpan);
+            if (copied < 4)
+            {
+                value = default;
+                return false;
+            }
+
+            if (littleEndian)
+            {
+                value = BinaryPrimitives.ReadInt32LittleEndian(tempSpan);
+            }
+            else
+            {
+                value = BinaryPrimitives.ReadInt32BigEndian(tempSpan);
+            }
+            reader.Skip(sizeof(int));
+            return true;
+        }
+    }
+}
diff --git a/src/System.Buffers.Experimental/System/Buffers/BufferReader_search.cs b/src/System.Buffers.Experimental/System/Buffers/BufferReader_search.cs
@@ -0,0 +1,61 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.Collections.Sequences;
+
+namespace System.Buffers
+{
+    // TODO: the TryReadUntill methods are very inneficient. We need to fix that.
+    public static partial class BufferReaderExtensions
+    {
+        public static bool TryReadUntill(ref BufferReader<ReadOnlyBytes> reader, out ReadOnlyBytes bytes, byte delimiter)
+        {
+            var copy = reader;
+            var start = reader.Position;
+            while (!reader.End) {
+                Position end = reader.Position;
+                if(reader.Take() == delimiter)
+                {
+                    bytes = new ReadOnlyBytes(start, end);
+                    return true;
+                }
+            }
+            reader = copy;
+            bytes = default;
+            return false;
+        }
+
+        public static bool TryReadUntill(ref BufferReader<ReadOnlyBytes> reader, out ReadOnlyBytes bytes, ReadOnlySpan<byte> delimiter)
+        {
+            if (delimiter.Length == 0)
+            {
+                bytes = ReadOnlyBytes.Empty;
+                return true;
+            }
+
+            int matched = 0;
+            var copy = reader;
+            var start = reader.Position;
+            var end = reader.Position;
+            while (!reader.End)
+            {
+                if (reader.Take() == delimiter[matched]) {
+                    matched++;
+                }
+                else
+                {
+                    end = reader.Position;
+                    matched = 0;
+                }
+                if(matched >= delimiter.Length)
+                {
+                    bytes = new ReadOnlyBytes(start, end);
+                    return true;
+                }
+            }
+            reader = copy;
+            bytes = default;
+            return false;
+        }
+    }
+}
diff --git a/src/System.Buffers.Experimental/System/Buffers/BufferReader_text.cs b/src/System.Buffers.Experimental/System/Buffers/BufferReader_text.cs
@@ -0,0 +1,83 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.Buffers.Text;
+using System.Collections.Sequences;
+
+namespace System.Buffers
+{
+    public static partial class BufferReaderExtensions 
+    {
+        public static bool TryParse<TSequence>(ref BufferReader<TSequence> reader, out bool value) 
+            where TSequence : ISequence<ReadOnlyMemory<byte>>
+        {
+            var unread = reader.UnreadSegment;
+            if (Utf8Parser.TryParse(unread, out value, out int consumed))
+            {
+                if (unread.Length > consumed)
+                {
+                    reader.Skip(consumed);
+                    return true;
+                }
+            }
+
+            Span<byte> tempSpan = stackalloc byte[5];
+            var copied = BufferReader.Peek(reader, tempSpan);
+            if (Utf8Parser.TryParse(tempSpan.Slice(0, copied), out value, out consumed))
+            {
+                reader.Skip(consumed);
+                return true;
+            }
+
+            return false;
+        }
+
+        public static bool TryParse<TSequence>(ref BufferReader<TSequence> reader, out int value)
+            where TSequence : ISequence<ReadOnlyMemory<byte>>
+        {
+            var unread = reader.UnreadSegment;
+            if (Utf8Parser.TryParse(unread, out value, out int consumed))
+            {
+                if (unread.Length > consumed)
+                {
+                    reader.Skip(consumed);
+                    return true;
+                }
+            }
+
+            Span<byte> tempSpan = stackalloc byte[15];
+            var copied = BufferReader.Peek(reader, tempSpan);
+            if (Utf8Parser.TryParse(tempSpan.Slice(0, copied), out value, out consumed))
+            {
+                reader.Skip(consumed);
+                return true;
+            }
+
+            return false;
+        }
+
+        public static bool TryParse<TSequence>(ref BufferReader<TSequence> reader, out ulong value)
+            where TSequence : ISequence<ReadOnlyMemory<byte>>
+        {
+            var unread = reader.UnreadSegment;
+            if (Utf8Parser.TryParse(unread, out value, out int consumed))
+            {
+                if (unread.Length > consumed)
+                {
+                    reader.Skip(consumed);
+                    return true;
+                }
+            }
+
+            Span<byte> tempSpan = stackalloc byte[30];
+            var copied = BufferReader.Peek(reader, tempSpan);
+            if (Utf8Parser.TryParse(tempSpan.Slice(0, copied), out value, out consumed))
+            {
+                reader.Skip(consumed);
+                return true;
+            }
+
+            return false;
+        }
+    }
+}
diff --git a/src/System.Buffers.Experimental/System/Buffers/Sequences/ReadOnlyBytes.cs b/src/System.Buffers.Experimental/System/Buffers/Sequences/ReadOnlyBytes.cs
@@ -283,7 +283,14 @@ public bool TryGet(ref Position position, out ReadOnlyMemory<byte> item, bool ad
             {
                 var start = (int)position;
                 var length = _endIndex - (int)position;
-                item = new ReadOnlyMemory<byte>(array, start, length);
+                if (length == 0)
+                {
+                    item = ReadOnlyMemory<byte>.Empty;
+                }
+                else
+                {
+                    item = new ReadOnlyMemory<byte>(array, start, length);
+                }
                 if (advance) position = default;
                 return true;
             }
@@ -304,6 +311,16 @@ public bool TryGet(ref Position position, out ReadOnlyMemory<byte> item, bool ad
                 return true;
             }
 
+            var om = _start as OwnedMemory<byte>;
+            if (om != null)
+            {
+                var start = (int)position;
+                var length = _endIndex - (int)position;
+                item = om.Memory.Slice(start, length);
+                if (advance) position = default;
+                return true;
+            }
+
             throw new NotImplementedException();
         }