Implemented TextReader.ReadLineAsync(CancellationToken) and TextReade…

…r.ReadToEndAsync(CancellationToken)
orthoxerox · May 13, 2021 · 22ed6ed · 22ed6ed
1 parent b7f54e9
commit 22ed6ed
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Showing 3 changed files with 27 additions and 15 deletions.
diff --git a/src/libraries/System.Private.CoreLib/src/System/IO/StreamReader.cs b/src/libraries/System.Private.CoreLib/src/System/IO/StreamReader.cs
@@ -813,8 +813,10 @@ private int ReadBuffer(Span<char> userBuffer, out bool readToUserBuffer)
             } while (ReadBuffer() > 0);
             return sb.ToString();
         }
+
+        public override Task<string?> ReadLineAsync() => ReadLineAsync(CancellationToken.None);
 
-        public override Task<string?> ReadLineAsync()
+        public override Task<string?> ReadLineAsync(CancellationToken cancellationToken)
         {
             // If we have been inherited into a subclass, the following implementation could be incorrect
             // since it does not call through to Read() which a subclass might have overridden.
@@ -828,15 +830,15 @@ private int ReadBuffer(Span<char> userBuffer, out bool readToUserBuffer)
             ThrowIfDisposed();
             CheckAsyncTaskInProgress();
 
-            Task<string?> task = ReadLineAsyncInternal();
+            Task<string?> task = ReadLineAsyncInternal(cancellationToken);
             _asyncReadTask = task;
 
             return task;
         }
 
-        private async Task<string?> ReadLineAsyncInternal()
+        private async Task<string?> ReadLineAsyncInternal(CancellationToken cancellationToken)
         {
-            if (_charPos == _charLen && (await ReadBufferAsync(CancellationToken.None).ConfigureAwait(false)) == 0)
+            if (_charPos == _charLen && (await ReadBufferAsync(cancellationToken).ConfigureAwait(false)) == 0)
             {
                 return null;
             }
@@ -872,7 +874,7 @@ private int ReadBuffer(Span<char> userBuffer, out bool readToUserBuffer)
 
                         _charPos = tmpCharPos = i + 1;
 
-                        if (ch == '\r' && (tmpCharPos < tmpCharLen || (await ReadBufferAsync(CancellationToken.None).ConfigureAwait(false)) > 0))
+                        if (ch == '\r' && (tmpCharPos < tmpCharLen || (await ReadBufferAsync(cancellationToken).ConfigureAwait(false)) > 0))
                         {
                             tmpCharPos = _charPos;
                             if (_charBuffer[tmpCharPos] == '\n')
@@ -890,12 +892,14 @@ private int ReadBuffer(Span<char> userBuffer, out bool readToUserBuffer)
                 i = tmpCharLen - tmpCharPos;
                 sb ??= new StringBuilder(i + 80);
                 sb.Append(tmpCharBuffer, tmpCharPos, i);
-            } while (await ReadBufferAsync(CancellationToken.None).ConfigureAwait(false) > 0);
+            } while (await ReadBufferAsync(cancellationToken).ConfigureAwait(false) > 0);
 
             return sb.ToString();
         }
 
-        public override Task<string> ReadToEndAsync()
+        public override Task<string> ReadToEndAsync() => ReadToEndAsync(CancellationToken.None);
+
+        public override Task<string> ReadToEndAsync(CancellationToken cancellationToken)
         {
             // If we have been inherited into a subclass, the following implementation could be incorrect
             // since it does not call through to Read() which a subclass might have overridden.
@@ -909,13 +913,13 @@ public override Task<string> ReadToEndAsync()
             ThrowIfDisposed();
             CheckAsyncTaskInProgress();
 
-            Task<string> task = ReadToEndAsyncInternal();
+            Task<string> task = ReadToEndAsyncInternal(cancellationToken);
             _asyncReadTask = task;
 
             return task;
         }
 
-        private async Task<string> ReadToEndAsyncInternal()
+        private async Task<string> ReadToEndAsyncInternal(CancellationToken cancellationToken)
         {
             // Call ReadBuffer, then pull data out of charBuffer.
             StringBuilder sb = new StringBuilder(_charLen - _charPos);
@@ -924,7 +928,7 @@ private async Task<string> ReadToEndAsyncInternal()
                 int tmpCharPos = _charPos;
                 sb.Append(_charBuffer, tmpCharPos, _charLen - tmpCharPos);
                 _charPos = _charLen;  // We consumed these characters
-                await ReadBufferAsync(CancellationToken.None).ConfigureAwait(false);
+                await ReadBufferAsync(cancellationToken).ConfigureAwait(false);
             } while (_charLen > 0);
 
             return sb.ToString();

diff --git a/src/libraries/System.Private.CoreLib/src/System/IO/StringReader.cs b/src/libraries/System.Private.CoreLib/src/System/IO/StringReader.cs
@@ -210,12 +210,16 @@ public override string ReadToEnd()
         }
 
         #region Task based Async APIs
-        public override Task<string?> ReadLineAsync()
+        public override Task<string?> ReadLineAsync() => ReadLineAsync(CancellationToken.None);
+
+        public override Task<string?> ReadLineAsync(CancellationToken cancellationToken)
         {
             return Task.FromResult(ReadLine());
         }
 
-        public override Task<string> ReadToEndAsync()
+        public override Task<string> ReadToEndAsync() => ReadToEndAsync(CancellationToken.None);
+
+        public override Task<string> ReadToEndAsync(CancellationToken cancellationToken)
         {
             return Task.FromResult(ReadToEnd());
         }

diff --git a/src/libraries/System.Private.CoreLib/src/System/IO/TextReader.cs b/src/libraries/System.Private.CoreLib/src/System/IO/TextReader.cs
@@ -203,18 +203,22 @@ public virtual int ReadBlock(Span<char> buffer)
         }
 
         #region Task based Async APIs
-        public virtual Task<string?> ReadLineAsync() =>
+        public virtual Task<string?> ReadLineAsync() => ReadLineAsync(CancellationToken.None);
+
+        public virtual async Task<string?> ReadLineAsync(CancellationToken cancellationToken) =>
             Task<string?>.Factory.StartNew(static state => ((TextReader)state!).ReadLine(), this,
                 CancellationToken.None, TaskCreationOptions.DenyChildAttach, TaskScheduler.Default);
 
-        public virtual async Task<string> ReadToEndAsync()
+        public virtual async Task<string> ReadToEndAsync() => ReadToEndAsync(CancellationToken.None);
+
+        public virtual async Task<string> ReadToEndAsync(CancellationToken cancellationToken)
         {
             var sb = new StringBuilder(4096);
             char[] chars = ArrayPool<char>.Shared.Rent(4096);
             try
             {
                 int len;
-                while ((len = await ReadAsyncInternal(chars, default).ConfigureAwait(false)) != 0)
+                while ((len = await ReadAsyncInternal(chars, cancellationToken).ConfigureAwait(false)) != 0)
                 {
                     sb.Append(chars, 0, len);
                 }