Made code in OperationQueue more readable; added new class PartialStream which wraps a segment of a larger stream as if it was a separate stream, allowing access to certain regions of a stream to be prohibited and headers of a stream to be cut off without requiring a lengthy copy operation
git-svn-id: file:///srv/devel/repo-conversion/nusu@134 d2e56fa2-650e-0410-a79f-9358c0239efd
This commit is contained in:
parent
1c317b3f66
commit
7e9e0e2bf1
|
@ -118,6 +118,10 @@
|
|||
<Compile Include="Source\Collections\ReverseComparer.Test.cs">
|
||||
<DependentUpon>ReverseComparer.cs</DependentUpon>
|
||||
</Compile>
|
||||
<Compile Include="Source\IO\PartialStream.cs" />
|
||||
<Compile Include="Source\IO\PartialStream.Test.cs">
|
||||
<DependentUpon>PartialStream.cs</DependentUpon>
|
||||
</Compile>
|
||||
<Compile Include="Source\IO\RingMemoryStream.cs" />
|
||||
<Compile Include="Source\IO\RingMemoryStream.Test.cs">
|
||||
<DependentUpon>RingMemoryStream.cs</DependentUpon>
|
||||
|
|
|
@ -100,6 +100,10 @@
|
|||
<Compile Include="Source\Collections\ReverseComparer.Test.cs">
|
||||
<DependentUpon>ReverseComparer.cs</DependentUpon>
|
||||
</Compile>
|
||||
<Compile Include="Source\IO\PartialStream.cs" />
|
||||
<Compile Include="Source\IO\PartialStream.Test.cs">
|
||||
<DependentUpon>PartialStream.cs</DependentUpon>
|
||||
</Compile>
|
||||
<Compile Include="Source\IO\RingMemoryStream.cs" />
|
||||
<Compile Include="Source\IO\RingMemoryStream.Test.cs">
|
||||
<DependentUpon>RingMemoryStream.cs</DependentUpon>
|
||||
|
|
515
Source/IO/PartialStream.Test.cs
Normal file
515
Source/IO/PartialStream.Test.cs
Normal file
|
@ -0,0 +1,515 @@
|
|||
#region CPL License
|
||||
/*
|
||||
Nuclex Framework
|
||||
Copyright (C) 2002-2009 Nuclex Development Labs
|
||||
|
||||
This library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the IBM Common Public License as
|
||||
published by the IBM Corporation; either version 1.0 of the
|
||||
License, or (at your option) any later version.
|
||||
|
||||
This library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
IBM Common Public License for more details.
|
||||
|
||||
You should have received a copy of the IBM Common Public
|
||||
License along with this library
|
||||
*/
|
||||
#endregion
|
||||
|
||||
#if UNITTEST
|
||||
|
||||
using System;
|
||||
using System.IO;
|
||||
|
||||
using NUnit.Framework;
|
||||
|
||||
namespace Nuclex.Support.IO {
|
||||
|
||||
/// <summary>Unit Test for the partial stream</summary>
|
||||
[TestFixture]
|
||||
public class PartialStreamTest {
|
||||
|
||||
#region class TestStream
|
||||
|
||||
/// <summary>Testing stream that allows specific features to be disabled</summary>
|
||||
private class TestStream : Stream {
|
||||
|
||||
/// <summary>Initializes a new test stream</summary>
|
||||
/// <param name="wrappedStream">Stream that will be wrapped</param>
|
||||
/// <param name="allowRead">Whether to allow reading from the stream</param>
|
||||
/// <param name="allowWrite">Whether to allow writing to the stream</param>
|
||||
/// <param name="allowSeek">Whether to allow seeking within the stream</param>
|
||||
public TestStream(
|
||||
Stream wrappedStream, bool allowRead, bool allowWrite, bool allowSeek
|
||||
) {
|
||||
this.stream = wrappedStream;
|
||||
this.readAllowed = allowRead;
|
||||
this.writeAllowed = allowWrite;
|
||||
this.seekAllowed = allowSeek;
|
||||
}
|
||||
|
||||
/// <summary>Whether data can be read from the stream</summary>
|
||||
public override bool CanRead {
|
||||
get { return this.readAllowed; }
|
||||
}
|
||||
|
||||
/// <summary>Whether the stream supports seeking</summary>
|
||||
public override bool CanSeek {
|
||||
get { return this.seekAllowed; }
|
||||
}
|
||||
|
||||
/// <summary>Whether data can be written into the stream</summary>
|
||||
public override bool CanWrite {
|
||||
get { return this.writeAllowed; }
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Clears all buffers for this stream and causes any buffered data to be written
|
||||
/// to the underlying device.
|
||||
/// </summary>
|
||||
public override void Flush() {
|
||||
++this.flushCallCount;
|
||||
this.stream.Flush();
|
||||
}
|
||||
|
||||
/// <summary>Length of the stream in bytes</summary>
|
||||
public override long Length {
|
||||
get {
|
||||
enforceSeekAllowed();
|
||||
return this.stream.Length;
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Absolute position of the file pointer within the stream</summary>
|
||||
/// <exception cref="NotSupportedException">
|
||||
/// At least one of the chained streams does not support seeking
|
||||
/// </exception>
|
||||
public override long Position {
|
||||
get {
|
||||
enforceSeekAllowed();
|
||||
return this.stream.Position;
|
||||
}
|
||||
set {
|
||||
enforceSeekAllowed();
|
||||
this.stream.Position = value;
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Reads a sequence of bytes from the stream and advances the position of
|
||||
/// the file pointer by the number of bytes read.
|
||||
/// </summary>
|
||||
/// <param name="buffer">Buffer that will receive the data read from the stream</param>
|
||||
/// <param name="offset">
|
||||
/// Offset in the buffer at which the stream will place the data read
|
||||
/// </param>
|
||||
/// <param name="count">Maximum number of bytes that will be read</param>
|
||||
/// <returns>
|
||||
/// The number of bytes that were actually read from the stream and written into
|
||||
/// the provided buffer
|
||||
/// </returns>
|
||||
public override int Read(byte[] buffer, int offset, int count) {
|
||||
enforceReadAllowed();
|
||||
return this.stream.Read(buffer, offset, count);
|
||||
}
|
||||
|
||||
/// <summary>Changes the position of the file pointer</summary>
|
||||
/// <param name="offset">
|
||||
/// Offset to move the file pointer by, relative to the position indicated by
|
||||
/// the <paramref name="origin" /> parameter.
|
||||
/// </param>
|
||||
/// <param name="origin">
|
||||
/// Reference point relative to which the file pointer is placed
|
||||
/// </param>
|
||||
/// <returns>The new absolute position within the stream</returns>
|
||||
public override long Seek(long offset, SeekOrigin origin) {
|
||||
enforceSeekAllowed();
|
||||
return this.stream.Seek(offset, origin);
|
||||
}
|
||||
|
||||
/// <summary>Changes the length of the stream</summary>
|
||||
/// <param name="value">New length the stream shall have</param>
|
||||
public override void SetLength(long value) {
|
||||
enforceSeekAllowed();
|
||||
this.stream.SetLength(value);
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Writes a sequence of bytes to the stream and advances the position of
|
||||
/// the file pointer by the number of bytes written.
|
||||
/// </summary>
|
||||
/// <param name="buffer">
|
||||
/// Buffer containing the data that will be written to the stream
|
||||
/// </param>
|
||||
/// <param name="offset">
|
||||
/// Offset in the buffer at which the data to be written starts
|
||||
/// </param>
|
||||
/// <param name="count">Number of bytes that will be written into the stream</param>
|
||||
public override void Write(byte[] buffer, int offset, int count) {
|
||||
enforceWriteAllowed();
|
||||
this.stream.Write(buffer, offset, count);
|
||||
}
|
||||
|
||||
/// <summary>Number of times the Flush() method has been called</summary>
|
||||
public int FlushCallCount {
|
||||
get { return this.flushCallCount; }
|
||||
}
|
||||
|
||||
/// <summary>Throws an exception if reading is not allowed</summary>
|
||||
private void enforceReadAllowed() {
|
||||
if(!this.readAllowed) {
|
||||
throw new NotSupportedException("Reading has been disabled");
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Throws an exception if writing is not allowed</summary>
|
||||
private void enforceWriteAllowed() {
|
||||
if(!this.writeAllowed) {
|
||||
throw new NotSupportedException("Writing has been disabled");
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Throws an exception if seeking is not allowed</summary>
|
||||
private void enforceSeekAllowed() {
|
||||
if(!this.seekAllowed) {
|
||||
throw new NotSupportedException("Seeking has been disabled");
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Stream being wrapped for testing</summary>
|
||||
private Stream stream;
|
||||
/// <summary>whether to allow reading from the wrapped stream</summary>
|
||||
private bool readAllowed;
|
||||
/// <summary>Whether to allow writing to the wrapped stream</summary>
|
||||
private bool writeAllowed;
|
||||
/// <summary>Whether to allow seeking within the wrapped stream</summary>
|
||||
private bool seekAllowed;
|
||||
/// <summary>Number of times the Flush() method has been called</summary>
|
||||
private int flushCallCount;
|
||||
|
||||
}
|
||||
|
||||
#endregion // class TestStream
|
||||
|
||||
/// <summary>Tests whether the partial stream constructor is working</summary>
|
||||
[Test]
|
||||
public void TestConstructor() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
memoryStream.SetLength(123);
|
||||
PartialStream partialStream = new PartialStream(memoryStream, 23, 100);
|
||||
Assert.AreEqual(100, partialStream.Length);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Verifies that the partial stream constructor throws an exception if
|
||||
/// it's invoked with an invalid start offset
|
||||
/// </summary>
|
||||
[Test, ExpectedException(typeof(ArgumentException))]
|
||||
public void TestThrowOnInvalidStartInConstructor() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
memoryStream.SetLength(123);
|
||||
PartialStream partialStream = new PartialStream(memoryStream, -1, 10);
|
||||
Assert.AreNotEqual(partialStream.Length, partialStream.Length);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Verifies that the partial stream constructor throws an exception if
|
||||
/// it's invoked with an invalid start offset
|
||||
/// </summary>
|
||||
[Test, ExpectedException(typeof(ArgumentException))]
|
||||
public void TestThrowOnInvalidLengthInConstructor() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
memoryStream.SetLength(123);
|
||||
PartialStream partialStream = new PartialStream(memoryStream, 100, 24);
|
||||
Assert.AreNotEqual(partialStream.Length, partialStream.Length);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Verifies that the partial stream constructor throws an exception if
|
||||
/// it's invoked with a start offset on an unseekable stream
|
||||
/// </summary>
|
||||
[Test, ExpectedException(typeof(ArgumentException))]
|
||||
public void TestThrowOnUnseekableStreamWithOffsetInConstructor() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
memoryStream.SetLength(123);
|
||||
TestStream testStream = new TestStream(memoryStream, true, true, false);
|
||||
PartialStream partialStream = new PartialStream(testStream, 23, 100);
|
||||
Assert.AreNotEqual(partialStream.Length, partialStream.Length);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Tests whether the CanRead property reports its status correctly
|
||||
/// </summary>
|
||||
[Test]
|
||||
public void TestCanReadProperty() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
TestStream yesStream = new TestStream(memoryStream, true, true, true);
|
||||
TestStream noStream = new TestStream(memoryStream, false, true, true);
|
||||
|
||||
Assert.IsTrue(new PartialStream(yesStream, 0, 0).CanRead);
|
||||
Assert.IsFalse(new PartialStream(noStream, 0, 0).CanRead);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Tests whether the CanWrite property reports its status correctly
|
||||
/// </summary>
|
||||
[Test]
|
||||
public void TestCanWriteProperty() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
TestStream yesStream = new TestStream(memoryStream, true, true, true);
|
||||
TestStream noStream = new TestStream(memoryStream, true, false, true);
|
||||
|
||||
Assert.IsTrue(new PartialStream(yesStream, 0, 0).CanWrite);
|
||||
Assert.IsFalse(new PartialStream(noStream, 0, 0).CanWrite);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Tests whether the CanSeek property reports its status correctly
|
||||
/// </summary>
|
||||
[Test]
|
||||
public void TestCanSeekProperty() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
TestStream yesStream = new TestStream(memoryStream, true, true, true);
|
||||
TestStream noStream = new TestStream(memoryStream, true, true, false);
|
||||
|
||||
Assert.IsTrue(new PartialStream(yesStream, 0, 0).CanSeek);
|
||||
Assert.IsFalse(new PartialStream(noStream, 0, 0).CanSeek);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Tests whether the CompleteStream property returns the original stream
|
||||
/// </summary>
|
||||
[Test]
|
||||
public void TestCompleteStreamProperty() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
PartialStream partialStream = new PartialStream(memoryStream, 0, 0);
|
||||
Assert.AreSame(memoryStream, partialStream.CompleteStream);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Tests whether the Flush() method can be called</summary>
|
||||
[Test]
|
||||
public void TestFlush() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
PartialStream partialStream = new PartialStream(memoryStream, 0, 0);
|
||||
partialStream.Flush();
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Tests whether the Position property correctly reports the file pointer position
|
||||
/// </summary>
|
||||
[Test]
|
||||
public void TestGetPosition() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
memoryStream.SetLength(123);
|
||||
PartialStream partialStream = new PartialStream(memoryStream, 23, 100);
|
||||
|
||||
Assert.AreEqual(0, partialStream.Position);
|
||||
|
||||
byte[] test = new byte[10];
|
||||
int bytesRead = partialStream.Read(test, 0, 10);
|
||||
|
||||
Assert.AreEqual(10, bytesRead);
|
||||
Assert.AreEqual(10, partialStream.Position);
|
||||
|
||||
bytesRead = partialStream.Read(test, 0, 10);
|
||||
|
||||
Assert.AreEqual(10, bytesRead);
|
||||
Assert.AreEqual(20, partialStream.Position);
|
||||
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Tests whether the Position property is correctly updated
|
||||
/// </summary>
|
||||
[Test]
|
||||
public void TestSetPosition() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
memoryStream.SetLength(123);
|
||||
PartialStream partialStream = new PartialStream(memoryStream, 23, 100);
|
||||
|
||||
Assert.AreEqual(0, partialStream.Position);
|
||||
partialStream.Position = 7;
|
||||
Assert.AreEqual(partialStream.Position, 7);
|
||||
partialStream.Position = 14;
|
||||
Assert.AreEqual(partialStream.Position, 14);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Tests whether the Position property throws an exception if the stream does
|
||||
/// not support seeking.
|
||||
/// </summary>
|
||||
[Test, ExpectedException(typeof(NotSupportedException))]
|
||||
public void TestThrowOnGetPositionOnUnseekableStream() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
TestStream testStream = new TestStream(memoryStream, true, true, false);
|
||||
|
||||
PartialStream partialStream = new PartialStream(testStream, 0, 0);
|
||||
Assert.AreEqual(-12345, partialStream.Position);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Tests whether the Position property throws an exception if the stream does
|
||||
/// not support seeking.
|
||||
/// </summary>
|
||||
[Test, ExpectedException(typeof(NotSupportedException))]
|
||||
public void TestThrowOnSetPositionOnUnseekableStream() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
TestStream testStream = new TestStream(memoryStream, true, true, false);
|
||||
|
||||
PartialStream partialStream = new PartialStream(testStream, 0, 0);
|
||||
partialStream.Position = 0;
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Tests whether the Read() method throws an exception if the stream does
|
||||
/// not support reading
|
||||
/// </summary>
|
||||
[Test, ExpectedException(typeof(NotSupportedException))]
|
||||
public void TestThrowOnReadFromUnreadableStream() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
TestStream testStream = new TestStream(memoryStream, false, true, true);
|
||||
PartialStream partialStream = new PartialStream(testStream, 0, 0);
|
||||
|
||||
byte[] test = new byte[10];
|
||||
int bytesRead = partialStream.Read(test, 0, 10);
|
||||
|
||||
Assert.AreNotEqual(bytesRead, bytesRead);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Tests whether the Seek() method of the partial stream is working
|
||||
/// </summary>
|
||||
[Test]
|
||||
public void TestSeeking() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
memoryStream.SetLength(20);
|
||||
PartialStream partialStream = new PartialStream(memoryStream, 0, 20);
|
||||
|
||||
Assert.AreEqual(7, partialStream.Seek(-13, SeekOrigin.End));
|
||||
Assert.AreEqual(14, partialStream.Seek(7, SeekOrigin.Current));
|
||||
Assert.AreEqual(11, partialStream.Seek(11, SeekOrigin.Begin));
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Tests whether the Seek() method throws an exception if an invalid
|
||||
/// reference point is provided
|
||||
/// </summary>
|
||||
[Test, ExpectedException(typeof(ArgumentException))]
|
||||
public void TestThrowOnInvalidSeekReferencePoint() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
PartialStream partialStream = new PartialStream(memoryStream, 0, 0);
|
||||
partialStream.Seek(1, (SeekOrigin)12345);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Verifies that the partial stream throws an exception if the attempt is
|
||||
/// made to change the length of the stream
|
||||
/// </summary>
|
||||
[Test, ExpectedException(typeof(NotSupportedException))]
|
||||
public void TestThrowOnLengthChange() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
PartialStream partialStream = new PartialStream(memoryStream, 0, 0);
|
||||
partialStream.SetLength(123);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Tests whether the Read() method returns 0 bytes if the attempt is made
|
||||
/// to read data from an invalid position
|
||||
/// </summary>
|
||||
[Test]
|
||||
public void TestReadFromInvalidPosition() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
memoryStream.SetLength(123);
|
||||
|
||||
memoryStream.Position = 1123;
|
||||
byte[] test = new byte[10];
|
||||
|
||||
Assert.AreEqual(0, memoryStream.Read(test, 0, 10));
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Verifies that the Read() method is working</summary>
|
||||
[Test]
|
||||
public void TestReadFromPartialStream() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
memoryStream.SetLength(123);
|
||||
|
||||
memoryStream.Position = 100;
|
||||
memoryStream.Write(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }, 0, 10);
|
||||
|
||||
PartialStream partialStream = new PartialStream(memoryStream, 95, 10);
|
||||
|
||||
byte[] buffer = new byte[15];
|
||||
int bytesRead = partialStream.Read(buffer, 0, 15);
|
||||
|
||||
Assert.AreEqual(10, bytesRead);
|
||||
Assert.AreEqual(
|
||||
new byte[] { 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 0, 0, 0, 0, 0 }, buffer
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Verifies that the Write() method is working</summary>
|
||||
[Test]
|
||||
public void TestWriteToPartialStream() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
memoryStream.SetLength(123);
|
||||
|
||||
memoryStream.Position = 60;
|
||||
memoryStream.Write(new byte[] { 11, 12, 13, 14, 15 }, 0, 5);
|
||||
|
||||
PartialStream partialStream = new PartialStream(memoryStream, 50, 15);
|
||||
partialStream.Position = 3;
|
||||
partialStream.Write(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }, 0, 10);
|
||||
|
||||
byte[] buffer = new byte[17];
|
||||
memoryStream.Position = 49;
|
||||
int bytesRead = memoryStream.Read(buffer, 0, 17);
|
||||
|
||||
Assert.AreEqual(17, bytesRead);
|
||||
Assert.AreEqual(
|
||||
new byte[] { 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 14, 15, 0 },
|
||||
buffer
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Verifies that an exception is thrown if the Write() method of the partial stream
|
||||
/// is attempted to be used to extend the partial stream's length
|
||||
/// </summary>
|
||||
[Test, ExpectedException(typeof(NotSupportedException))]
|
||||
public void TestThrowOnExtendPartialStream() {
|
||||
using(MemoryStream memoryStream = new MemoryStream()) {
|
||||
memoryStream.SetLength(25);
|
||||
|
||||
PartialStream partialStream = new PartialStream(memoryStream, 10, 10);
|
||||
partialStream.Position = 5;
|
||||
partialStream.Write(new byte[] { 1, 2, 3, 4, 5, 6 }, 0, 6);
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
} // namespace Nuclex.Support.IO
|
||||
|
||||
#endif // UNITTEST
|
264
Source/IO/PartialStream.cs
Normal file
264
Source/IO/PartialStream.cs
Normal file
|
@ -0,0 +1,264 @@
|
|||
#region CPL License
|
||||
/*
|
||||
Nuclex Framework
|
||||
Copyright (C) 2002-2009 Nuclex Development Labs
|
||||
|
||||
This library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the IBM Common Public License as
|
||||
published by the IBM Corporation; either version 1.0 of the
|
||||
License, or (at your option) any later version.
|
||||
|
||||
This library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
IBM Common Public License for more details.
|
||||
|
||||
You should have received a copy of the IBM Common Public
|
||||
License along with this library
|
||||
*/
|
||||
#endregion
|
||||
|
||||
using System;
|
||||
using System.Collections.Generic;
|
||||
using System.Diagnostics;
|
||||
using System.IO;
|
||||
|
||||
namespace Nuclex.Support.IO {
|
||||
|
||||
/// <summary>Wraps a stream and exposes only a limited region of its data</summary>
|
||||
public class PartialStream : Stream {
|
||||
|
||||
/// <summary>Initializes a new partial stream</summary>
|
||||
/// <param name="stream">
|
||||
/// Stream the wrapper will make a limited region accessible of
|
||||
/// </param>
|
||||
/// <param name="start">
|
||||
/// Start index in the stream which becomes the beginning for the wrapper
|
||||
/// </param>
|
||||
/// <param name="length">
|
||||
/// Length the wrapped stream should report and allow access to
|
||||
/// </param>
|
||||
public PartialStream(Stream stream, long start, long length) {
|
||||
if(start < 0) {
|
||||
throw new ArgumentException("Start index must not be less than 0", "start");
|
||||
}
|
||||
|
||||
if(!stream.CanSeek) {
|
||||
if(start != 0) {
|
||||
throw new ArgumentException(
|
||||
"The only valid start for unseekable streams is 0", "start"
|
||||
);
|
||||
}
|
||||
} else {
|
||||
if(start + length > stream.Length) {
|
||||
throw new ArgumentException(
|
||||
"Partial stream exceeds end of full stream", "length"
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
this.stream = stream;
|
||||
this.start = start;
|
||||
this.length = length;
|
||||
}
|
||||
|
||||
/// <summary>Whether data can be read from the stream</summary>
|
||||
public override bool CanRead {
|
||||
get { return this.stream.CanRead; }
|
||||
}
|
||||
|
||||
/// <summary>Whether the stream supports seeking</summary>
|
||||
public override bool CanSeek {
|
||||
get { return this.stream.CanSeek; }
|
||||
}
|
||||
|
||||
/// <summary>Whether data can be written into the stream</summary>
|
||||
public override bool CanWrite {
|
||||
get { return this.stream.CanWrite; }
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Clears all buffers for this stream and causes any buffered data to be written
|
||||
/// to the underlying device.
|
||||
/// </summary>
|
||||
public override void Flush() {
|
||||
this.stream.Flush();
|
||||
}
|
||||
|
||||
/// <summary>Length of the stream in bytes</summary>
|
||||
/// <exception cref="NotSupportedException">
|
||||
/// The wrapped stream does not support seeking
|
||||
/// </exception>
|
||||
public override long Length {
|
||||
get { return this.length; }
|
||||
}
|
||||
|
||||
/// <summary>Absolute position of the file pointer within the stream</summary>
|
||||
/// <exception cref="NotSupportedException">
|
||||
/// The wrapped stream does not support seeking
|
||||
/// </exception>
|
||||
public override long Position {
|
||||
get {
|
||||
if(!this.stream.CanSeek) {
|
||||
throw makeSeekNotSupportedException("seek");
|
||||
}
|
||||
|
||||
return this.position;
|
||||
}
|
||||
set { moveFilePointer(value); }
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Reads a sequence of bytes from the stream and advances the position of
|
||||
/// the file pointer by the number of bytes read.
|
||||
/// </summary>
|
||||
/// <param name="buffer">Buffer that will receive the data read from the stream</param>
|
||||
/// <param name="offset">
|
||||
/// Offset in the buffer at which the stream will place the data read
|
||||
/// </param>
|
||||
/// <param name="count">Maximum number of bytes that will be read</param>
|
||||
/// <returns>
|
||||
/// The number of bytes that were actually read from the stream and written into
|
||||
/// the provided buffer
|
||||
/// </returns>
|
||||
/// <exception cref="NotSupportedException">
|
||||
/// The wrapped stream does not support reading
|
||||
/// </exception>
|
||||
public override int Read(byte[] buffer, int offset, int count) {
|
||||
if(!this.stream.CanRead) {
|
||||
throw new NotSupportedException(
|
||||
"Can't read: the wrapped stream doesn't support reading"
|
||||
);
|
||||
}
|
||||
|
||||
long remaining = this.length - this.position;
|
||||
int bytesToRead = (int)Math.Min(count, remaining);
|
||||
|
||||
if(this.stream.CanSeek) {
|
||||
this.stream.Position = this.position + this.start;
|
||||
}
|
||||
int bytesRead = this.stream.Read(buffer, offset, bytesToRead);
|
||||
this.position += bytesRead;
|
||||
|
||||
return bytesRead;
|
||||
}
|
||||
|
||||
/// <summary>Changes the position of the file pointer</summary>
|
||||
/// <param name="offset">
|
||||
/// Offset to move the file pointer by, relative to the position indicated by
|
||||
/// the <paramref name="origin" /> parameter.
|
||||
/// </param>
|
||||
/// <param name="origin">
|
||||
/// Reference point relative to which the file pointer is placed
|
||||
/// </param>
|
||||
/// <returns>The new absolute position within the stream</returns>
|
||||
public override long Seek(long offset, SeekOrigin origin) {
|
||||
switch(origin) {
|
||||
case SeekOrigin.Begin: {
|
||||
return Position = offset;
|
||||
}
|
||||
case SeekOrigin.Current: {
|
||||
return Position += offset;
|
||||
}
|
||||
case SeekOrigin.End: {
|
||||
return Position = (Length + offset);
|
||||
}
|
||||
default: {
|
||||
throw new ArgumentException("Invalid seek origin", "origin");
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Changes the length of the stream</summary>
|
||||
/// <param name="value">New length the stream shall have</param>
|
||||
/// <exception cref="NotSupportedException">
|
||||
/// Always, the stream chainer does not support the SetLength() operation
|
||||
/// </exception>
|
||||
public override void SetLength(long value) {
|
||||
throw new NotSupportedException("Resizing partial streams is not supported");
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Writes a sequence of bytes to the stream and advances the position of
|
||||
/// the file pointer by the number of bytes written.
|
||||
/// </summary>
|
||||
/// <param name="buffer">
|
||||
/// Buffer containing the data that will be written to the stream
|
||||
/// </param>
|
||||
/// <param name="offset">
|
||||
/// Offset in the buffer at which the data to be written starts
|
||||
/// </param>
|
||||
/// <param name="count">Number of bytes that will be written into the stream</param>
|
||||
/// <remarks>
|
||||
/// The behavior of this method is as follows: If one or more chained streams
|
||||
/// do not support seeking, all data is appended to the final stream in the
|
||||
/// chain. Otherwise, writing will begin with the stream the current file pointer
|
||||
/// offset falls into. If the end of that stream is reached, writing continues
|
||||
/// in the next stream. On the last stream, writing more data into the stream
|
||||
/// that it current size allows will enlarge the stream.
|
||||
/// </remarks>
|
||||
public override void Write(byte[] buffer, int offset, int count) {
|
||||
long remaining = this.length - this.position;
|
||||
if(count > remaining) {
|
||||
throw new NotSupportedException(
|
||||
"Cannot extend the length of the partial stream"
|
||||
);
|
||||
}
|
||||
|
||||
if(this.stream.CanSeek) {
|
||||
this.stream.Position = this.position + this.start;
|
||||
}
|
||||
this.stream.Write(buffer, offset, count);
|
||||
|
||||
this.position += count;
|
||||
}
|
||||
|
||||
/// <summary>Stream being wrapped by the partial stream wrapper</summary>
|
||||
public Stream CompleteStream {
|
||||
get { return this.stream; }
|
||||
}
|
||||
|
||||
/// <summary>Moves the file pointer</summary>
|
||||
/// <param name="position">New position the file pointer will be moved to</param>
|
||||
private void moveFilePointer(long position) {
|
||||
if(!this.stream.CanSeek) {
|
||||
throw makeSeekNotSupportedException("seek");
|
||||
}
|
||||
|
||||
// Seemingly, it is okay to move the file pointer beyond the end of
|
||||
// the stream until you try to Read() or Write()
|
||||
this.position = position;
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Constructs a NotSupportException for an error caused by the wrapped
|
||||
/// stream having no seek support
|
||||
/// </summary>
|
||||
/// <param name="action">Action that was tried to perform</param>
|
||||
/// <returns>The newly constructed NotSupportedException</returns>
|
||||
private static NotSupportedException makeSeekNotSupportedException(string action) {
|
||||
return new NotSupportedException(
|
||||
string.Format(
|
||||
"Can't {0}: the wrapped stream does not support seeking",
|
||||
action
|
||||
)
|
||||
);
|
||||
}
|
||||
|
||||
/// <summary>Streams that have been chained together</summary>
|
||||
private Stream stream;
|
||||
/// <summary>Start index of the partial stream in the wrapped stream</summary>
|
||||
private long start;
|
||||
/// <summary>Zero-based position of the partial stream's file pointer</summary>
|
||||
/// <remarks>
|
||||
/// If the stream does not support seeking, the position will simply be counted
|
||||
/// up until it reaches <see cref="PartialStream.length" />.
|
||||
/// </remarks>
|
||||
private long position;
|
||||
/// <summary>Length of the partial stream</summary>
|
||||
private long length;
|
||||
|
||||
|
||||
}
|
||||
|
||||
} // namespace Nuclex.Support.IO
|
|
@ -119,10 +119,10 @@ namespace Nuclex.Support.Scheduling {
|
|||
copy(this, eventArguments);
|
||||
}
|
||||
|
||||
/// <summary>Prepares the current operation and calls its Begin() method</summary>
|
||||
/// <summary>Prepares the current operation and calls its Start() method</summary>
|
||||
/// <remarks>
|
||||
/// This subscribes the queue to the events of to the current operation
|
||||
/// and launches the operation by calling its Begin() method.
|
||||
/// and launches the operation by calling its Start() method.
|
||||
/// </remarks>
|
||||
private void startCurrentOperation() {
|
||||
OperationType operation = this.children[this.currentOperationIndex].Transaction;
|
||||
|
@ -168,8 +168,8 @@ namespace Nuclex.Support.Scheduling {
|
|||
|
||||
/// <summary>Called when the current executing operation ends</summary>
|
||||
/// <param name="sender">Operation that ended</param>
|
||||
/// <param name="e">Not used</param>
|
||||
private void asyncOperationEnded(object sender, EventArgs e) {
|
||||
/// <param name="arguments">Not used</param>
|
||||
private void asyncOperationEnded(object sender, EventArgs arguments) {
|
||||
|
||||
// Unsubscribe from the current operation's events and update the
|
||||
// accumulating progress counter
|
||||
|
@ -196,16 +196,17 @@ namespace Nuclex.Support.Scheduling {
|
|||
|
||||
/// <summary>Called when currently executing operation makes progress</summary>
|
||||
/// <param name="sender">Operation that has achieved progress</param>
|
||||
/// <param name="e">Not used</param>
|
||||
private void asyncOperationProgressChanged(object sender, ProgressReportEventArgs e) {
|
||||
/// <param name="arguments">Not used</param>
|
||||
private void asyncOperationProgressChanged(
|
||||
object sender, ProgressReportEventArgs arguments
|
||||
) {
|
||||
|
||||
// Determine the completed weight of the currently executing operation
|
||||
float currentOperationCompletedWeight =
|
||||
e.Progress * this.children[this.currentOperationIndex].Weight;
|
||||
float operationWeight = this.children[this.currentOperationIndex].Weight;
|
||||
float operationCompletedWeight = arguments.Progress * operationWeight;
|
||||
|
||||
// Build the total normalized amount of progress for the queue
|
||||
float progress =
|
||||
(this.completedWeight + currentOperationCompletedWeight) / this.totalWeight;
|
||||
float progress = (this.completedWeight + operationCompletedWeight) / this.totalWeight;
|
||||
|
||||
// Done, we can send the actual progress to any event subscribers
|
||||
OnAsyncProgressChanged(progress);
|
||||
|
|
Loading…
Reference in New Issue
Block a user