74 lines
2.3 KiB
C#
74 lines
2.3 KiB
C#
//
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// FixedSizeReadStream.cs
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//
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// Author:
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// Martin Baulig <mabaul@microsoft.com>
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//
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// Copyright (c) 2018 Xamarin Inc. (http://www.xamarin.com)
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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using System;
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using System.IO;
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using System.Threading;
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using System.Threading.Tasks;
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namespace System.Net
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{
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class FixedSizeReadStream : WebReadStream
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{
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public long ContentLength {
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get;
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}
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long position;
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public FixedSizeReadStream (WebOperation operation, Stream innerStream,
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long contentLength)
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: base (operation, innerStream)
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{
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ContentLength = contentLength;
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}
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protected override async Task<int> ProcessReadAsync (
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byte[] buffer, int offset, int size,
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CancellationToken cancellationToken)
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{
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cancellationToken.ThrowIfCancellationRequested ();
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var remaining = ContentLength - position;
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WebConnection.Debug ($"{ME} READ: position={position} length={ContentLength} size={size} remaining={remaining}");
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if (remaining == 0)
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return 0;
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var readSize = (int)Math.Min (remaining, size);
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WebConnection.Debug ($"{ME} READ #1: readSize={readSize}");
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var ret = await InnerStream.ReadAsync (
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buffer, offset, readSize, cancellationToken).ConfigureAwait (false);
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WebConnection.Debug ($"{ME} READ #2: ret={ret}");
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if (ret <= 0)
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return ret;
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position += ret;
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return ret;
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}
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}
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}
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