Mark bytes as consumed #13372 (#13394)

src/Http/WebUtilities/src/FormPipeReader.cs

@@ -252,6 +252,8 @@ namespace Microsoft.AspNetCore.WebUtilities
                 {
                     ParseFormValuesFast(keyValuePair.FirstSpan, ref accumulator, isFinalBlock: true, out var segmentConsumed);
                     Debug.Assert(segmentConsumed == keyValuePair.FirstSpan.Length);
+                    consumedBytes = sequenceReader.Consumed;
+                    consumed = sequenceReader.Position;
                     continue;
                 }
 

src/Http/WebUtilities/test/FormPipeReaderTests.cs

@@ -184,6 +184,7 @@ namespace Microsoft.AspNetCore.WebUtilities
             var formReader = new FormPipeReader(null, encoding);
 
             formReader.ParseFormValues(ref readOnlySequence, ref accumulator, isFinalBlock: true);
+            Assert.True(readOnlySequence.IsEmpty);
 
             Assert.Equal(2, accumulator.KeyCount);
             var dict = accumulator.GetResults();
@@ -201,6 +202,7 @@ namespace Microsoft.AspNetCore.WebUtilities
 
             var formReader = new FormPipeReader(null, encoding);
             formReader.ParseFormValues(ref readOnlySequence, ref accumulator, isFinalBlock: true);
+            Assert.True(readOnlySequence.IsEmpty);
 
             Assert.Equal(3, accumulator.KeyCount);
             var dict = accumulator.GetResults();
@@ -219,6 +221,7 @@ namespace Microsoft.AspNetCore.WebUtilities
 
             var formReader = new FormPipeReader(null, encoding);
             formReader.ParseFormValues(ref readOnlySequence, ref accumulator, isFinalBlock: true);
+            Assert.True(readOnlySequence.IsEmpty);
 
             Assert.Equal(3, accumulator.KeyCount);
             var dict = accumulator.GetResults();
@@ -237,6 +240,7 @@ namespace Microsoft.AspNetCore.WebUtilities
 
             var formReader = new FormPipeReader(null, encoding);
             formReader.ParseFormValues(ref readOnlySequence, ref accumulator, isFinalBlock: true);
+            Assert.True(readOnlySequence.IsEmpty);
 
             Assert.Equal(2, accumulator.KeyCount);
             var dict = accumulator.GetResults();
@@ -254,6 +258,7 @@ namespace Microsoft.AspNetCore.WebUtilities
 
             var formReader = new FormPipeReader(null, encoding);
             formReader.ParseFormValues(ref readOnlySequence, ref accumulator, isFinalBlock: true);
+            Assert.True(readOnlySequence.IsEmpty);
 
             Assert.Equal(3, accumulator.KeyCount);
             var dict = accumulator.GetResults();
@@ -272,6 +277,7 @@ namespace Microsoft.AspNetCore.WebUtilities
 
             var formReader = new FormPipeReader(null, encoding);
             formReader.ParseFormValues(ref readOnlySequence, ref accumulator, isFinalBlock: true);
+            Assert.True(readOnlySequence.IsEmpty);
 
             Assert.Equal(3, accumulator.KeyCount);
             var dict = accumulator.GetResults();
@@ -290,6 +296,7 @@ namespace Microsoft.AspNetCore.WebUtilities
 
             var formReader = new FormPipeReader(null, encoding);
             formReader.ParseFormValues(ref readOnlySequence, ref accumulator, isFinalBlock: true);
+            Assert.True(readOnlySequence.IsEmpty);
 
             Assert.Equal(2, accumulator.KeyCount);
             var dict = accumulator.GetResults();
@@ -297,6 +304,23 @@ namespace Microsoft.AspNetCore.WebUtilities
             Assert.Equal("wow", dict["\"%-.<>\\^_`{|}"]);
         }
 
+        [Fact]
+        public void TryParseFormValues_MultiSegmentFastPathWorks()
+        {
+            var readOnlySequence = ReadOnlySequenceFactory.CreateSegments(Encoding.UTF8.GetBytes("foo=bar&"), Encoding.UTF8.GetBytes("baz=boo"));
+
+            KeyValueAccumulator accumulator = default;
+
+            var formReader = new FormPipeReader(null);
+            formReader.ParseFormValues(ref readOnlySequence, ref accumulator, isFinalBlock: true);
+            Assert.True(readOnlySequence.IsEmpty);
+
+            Assert.Equal(2, accumulator.KeyCount);
+            var dict = accumulator.GetResults();
+            Assert.Equal("bar", dict["foo"]);
+            Assert.Equal("boo", dict["baz"]);
+        }
+
         [Fact]
         public void TryParseFormValues_ExceedKeyLengthThrows()
         {
@@ -411,6 +435,7 @@ namespace Microsoft.AspNetCore.WebUtilities
             };
 
             formReader.ParseFormValues(ref readOnlySequence, ref accumulator, isFinalBlock: true);
+            Assert.True(readOnlySequence.IsEmpty);
 
             IDictionary<string, StringValues> values = accumulator.GetResults();
             Assert.Contains("fo", values);
@@ -431,6 +456,7 @@ namespace Microsoft.AspNetCore.WebUtilities
             };
 
             formReader.ParseFormValues(ref readOnlySequence, ref accumulator, isFinalBlock: true);
+            Assert.True(readOnlySequence.IsEmpty);
 
             IDictionary<string, StringValues> values = accumulator.GetResults();
             Assert.Contains("fo", values);