Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / Framework / MS / Internal / IO / Packaging / ManagedIStream.cs / 1305600 / ManagedIStream.cs
//---------------------------------------------------------------------------- // //// Copyright (C) Microsoft Corporation. All rights reserved. // // // Description: // Implements an IStream component initialized from an // object of type System.IO.Stream. // // History: // 03/28/2004: JohnLarc: Initial implementation //--------------------------------------------------------------------------- using System; using System.IO; using System.Diagnostics; // for Assert using System.IO.Packaging; // for native APIs using System.Runtime.InteropServices; // for Marshal, COMException, etc. using System.Runtime.InteropServices.ComTypes; // for IStream using System.Windows; // for ExceptionStringTable using System.Security; // for SecurityCritical using MS.Win32; // for NativeMethods namespace MS.Internal.IO.Packaging { // The class ManagedIStream is not COM-visible. Its purpose is to be able to invoke COM interfaces // from managed code rather than the contrary. internal class ManagedIStream : IStream { ////// Constructor /// internal ManagedIStream(Stream ioStream) { if (ioStream == null) { throw new ArgumentNullException("ioStream"); } _ioStream = ioStream; } ////// Read at most bufferSize bytes into buffer and return the effective /// number of bytes read in bytesReadPtr (unless null). /// ////// mscorlib disassembly shows the following MarshalAs parameters /// void Read([Out, MarshalAs(UnmanagedType.LPArray, SizeParamIndex=1)] byte[] pv, int cb, IntPtr pcbRead); /// This means marshaling code will have found the size of the array buffer in the parameter bufferSize. /// ////// Critical: calls Marshal.WriteInt32 which LinkDemands, takes pointers as input /// [SecurityCritical] void IStream.Read(Byte[] buffer, Int32 bufferSize, IntPtr bytesReadPtr) { Int32 bytesRead = _ioStream.Read(buffer, 0, (int) bufferSize); if (bytesReadPtr != IntPtr.Zero) { Marshal.WriteInt32(bytesReadPtr, bytesRead); } } ////// Move the stream pointer to the specified position. /// ////// System.IO.stream supports searching past the end of the stream, like /// OLE streams. /// newPositionPtr is not an out parameter because the method is required /// to accept NULL pointers. /// ////// Critical: calls Marshal.WriteInt64 which LinkDemands, takes pointers as input /// [SecurityCritical] void IStream.Seek(Int64 offset, Int32 origin, IntPtr newPositionPtr) { SeekOrigin seekOrigin; // The operation will generally be I/O bound, so there is no point in // eliminating the following switch by playing on the fact that // System.IO uses the same integer values as IStream for SeekOrigin. switch(origin) { case NativeMethods.STREAM_SEEK_SET: seekOrigin = SeekOrigin.Begin; break; case NativeMethods.STREAM_SEEK_CUR: seekOrigin = SeekOrigin.Current; break; case NativeMethods.STREAM_SEEK_END: seekOrigin = SeekOrigin.End; break; default: throw new ArgumentOutOfRangeException("origin"); } long position = _ioStream.Seek(offset, seekOrigin); // Dereference newPositionPtr and assign to the pointed location. if (newPositionPtr != IntPtr.Zero) { Marshal.WriteInt64(newPositionPtr, position); } } ////// Sets stream's size. /// void IStream.SetSize(Int64 libNewSize) { _ioStream.SetLength(libNewSize); } ////// Obtain stream stats. /// ////// STATSG has to be qualified because it is defined both in System.Runtime.InteropServices and /// System.Runtime.InteropServices.ComTypes. /// The STATSTG structure is shared by streams, storages and byte arrays. Members irrelevant to streams /// or not available from System.IO.Stream are not returned, which leaves only cbSize and grfMode as /// meaningful and available pieces of information. /// grfStatFlag is used to indicate whether the stream name should be returned and is ignored because /// this information is unavailable. /// void IStream.Stat(out System.Runtime.InteropServices.ComTypes.STATSTG streamStats, int grfStatFlag) { streamStats = new System.Runtime.InteropServices.ComTypes.STATSTG(); streamStats.type = NativeMethods.STGTY_STREAM; streamStats.cbSize = _ioStream.Length; // Return access information in grfMode. streamStats.grfMode = 0; // default value for each flag will be false if (_ioStream.CanRead && _ioStream.CanWrite) { streamStats.grfMode |= NativeMethods.STGM_READWRITE; } else if (_ioStream.CanRead) { streamStats.grfMode |= NativeMethods.STGM_READ; } else if (_ioStream.CanWrite) { streamStats.grfMode |= NativeMethods.STGM_WRITE; } else { // A stream that is neither readable nor writable is a closed stream. // Note the use of an exception that is known to the interop marshaller // (unlike ObjectDisposedException). throw new IOException(SR.Get(SRID.StreamObjectDisposed)); } } ////// Write at most bufferSize bytes from buffer. /// ////// Critical: calls Marshal.WriteInt32 which LinkDemands, takes pointers as input /// [SecurityCritical] void IStream.Write(Byte[] buffer, Int32 bufferSize, IntPtr bytesWrittenPtr) { _ioStream.Write(buffer, 0, bufferSize); if (bytesWrittenPtr != IntPtr.Zero) { // If fewer than bufferSize bytes had been written, an exception would // have been thrown, so it can be assumed we wrote bufferSize bytes. Marshal.WriteInt32(bytesWrittenPtr, bufferSize); } } #region Unimplemented methods ////// Create a clone. /// ////// Not implemented. /// void IStream.Clone(out IStream streamCopy) { streamCopy = null; throw new NotSupportedException(); } ////// Read at most bufferSize bytes from the receiver and write them to targetStream. /// ////// Not implemented. /// void IStream.CopyTo(IStream targetStream, Int64 bufferSize, IntPtr buffer, IntPtr bytesWrittenPtr) { throw new NotSupportedException(); } ////// Commit changes. /// ////// Only relevant to transacted streams. /// void IStream.Commit(Int32 flags) { throw new NotSupportedException(); } ////// Lock at most byteCount bytes starting at offset. /// ////// Not supported by System.IO.Stream. /// void IStream.LockRegion(Int64 offset, Int64 byteCount, Int32 lockType) { throw new NotSupportedException(); } ////// Undo writes performed since last Commit. /// ////// Relevant only to transacted streams. /// void IStream.Revert() { throw new NotSupportedException(); } ////// Unlock the specified region. /// ////// Not supported by System.IO.Stream. /// void IStream.UnlockRegion(Int64 offset, Int64 byteCount, Int32 lockType) { throw new NotSupportedException(); } #endregion Unimplemented methods #region Fields private Stream _ioStream; #endregion Fields } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved. //---------------------------------------------------------------------------- // //// Copyright (C) Microsoft Corporation. All rights reserved. // // // Description: // Implements an IStream component initialized from an // object of type System.IO.Stream. // // History: // 03/28/2004: JohnLarc: Initial implementation //--------------------------------------------------------------------------- using System; using System.IO; using System.Diagnostics; // for Assert using System.IO.Packaging; // for native APIs using System.Runtime.InteropServices; // for Marshal, COMException, etc. using System.Runtime.InteropServices.ComTypes; // for IStream using System.Windows; // for ExceptionStringTable using System.Security; // for SecurityCritical using MS.Win32; // for NativeMethods namespace MS.Internal.IO.Packaging { // The class ManagedIStream is not COM-visible. Its purpose is to be able to invoke COM interfaces // from managed code rather than the contrary. internal class ManagedIStream : IStream { ////// Constructor /// internal ManagedIStream(Stream ioStream) { if (ioStream == null) { throw new ArgumentNullException("ioStream"); } _ioStream = ioStream; } ////// Read at most bufferSize bytes into buffer and return the effective /// number of bytes read in bytesReadPtr (unless null). /// ////// mscorlib disassembly shows the following MarshalAs parameters /// void Read([Out, MarshalAs(UnmanagedType.LPArray, SizeParamIndex=1)] byte[] pv, int cb, IntPtr pcbRead); /// This means marshaling code will have found the size of the array buffer in the parameter bufferSize. /// ////// Critical: calls Marshal.WriteInt32 which LinkDemands, takes pointers as input /// [SecurityCritical] void IStream.Read(Byte[] buffer, Int32 bufferSize, IntPtr bytesReadPtr) { Int32 bytesRead = _ioStream.Read(buffer, 0, (int) bufferSize); if (bytesReadPtr != IntPtr.Zero) { Marshal.WriteInt32(bytesReadPtr, bytesRead); } } ////// Move the stream pointer to the specified position. /// ////// System.IO.stream supports searching past the end of the stream, like /// OLE streams. /// newPositionPtr is not an out parameter because the method is required /// to accept NULL pointers. /// ////// Critical: calls Marshal.WriteInt64 which LinkDemands, takes pointers as input /// [SecurityCritical] void IStream.Seek(Int64 offset, Int32 origin, IntPtr newPositionPtr) { SeekOrigin seekOrigin; // The operation will generally be I/O bound, so there is no point in // eliminating the following switch by playing on the fact that // System.IO uses the same integer values as IStream for SeekOrigin. switch(origin) { case NativeMethods.STREAM_SEEK_SET: seekOrigin = SeekOrigin.Begin; break; case NativeMethods.STREAM_SEEK_CUR: seekOrigin = SeekOrigin.Current; break; case NativeMethods.STREAM_SEEK_END: seekOrigin = SeekOrigin.End; break; default: throw new ArgumentOutOfRangeException("origin"); } long position = _ioStream.Seek(offset, seekOrigin); // Dereference newPositionPtr and assign to the pointed location. if (newPositionPtr != IntPtr.Zero) { Marshal.WriteInt64(newPositionPtr, position); } } ////// Sets stream's size. /// void IStream.SetSize(Int64 libNewSize) { _ioStream.SetLength(libNewSize); } ////// Obtain stream stats. /// ////// STATSG has to be qualified because it is defined both in System.Runtime.InteropServices and /// System.Runtime.InteropServices.ComTypes. /// The STATSTG structure is shared by streams, storages and byte arrays. Members irrelevant to streams /// or not available from System.IO.Stream are not returned, which leaves only cbSize and grfMode as /// meaningful and available pieces of information. /// grfStatFlag is used to indicate whether the stream name should be returned and is ignored because /// this information is unavailable. /// void IStream.Stat(out System.Runtime.InteropServices.ComTypes.STATSTG streamStats, int grfStatFlag) { streamStats = new System.Runtime.InteropServices.ComTypes.STATSTG(); streamStats.type = NativeMethods.STGTY_STREAM; streamStats.cbSize = _ioStream.Length; // Return access information in grfMode. streamStats.grfMode = 0; // default value for each flag will be false if (_ioStream.CanRead && _ioStream.CanWrite) { streamStats.grfMode |= NativeMethods.STGM_READWRITE; } else if (_ioStream.CanRead) { streamStats.grfMode |= NativeMethods.STGM_READ; } else if (_ioStream.CanWrite) { streamStats.grfMode |= NativeMethods.STGM_WRITE; } else { // A stream that is neither readable nor writable is a closed stream. // Note the use of an exception that is known to the interop marshaller // (unlike ObjectDisposedException). throw new IOException(SR.Get(SRID.StreamObjectDisposed)); } } ////// Write at most bufferSize bytes from buffer. /// ////// Critical: calls Marshal.WriteInt32 which LinkDemands, takes pointers as input /// [SecurityCritical] void IStream.Write(Byte[] buffer, Int32 bufferSize, IntPtr bytesWrittenPtr) { _ioStream.Write(buffer, 0, bufferSize); if (bytesWrittenPtr != IntPtr.Zero) { // If fewer than bufferSize bytes had been written, an exception would // have been thrown, so it can be assumed we wrote bufferSize bytes. Marshal.WriteInt32(bytesWrittenPtr, bufferSize); } } #region Unimplemented methods ////// Create a clone. /// ////// Not implemented. /// void IStream.Clone(out IStream streamCopy) { streamCopy = null; throw new NotSupportedException(); } ////// Read at most bufferSize bytes from the receiver and write them to targetStream. /// ////// Not implemented. /// void IStream.CopyTo(IStream targetStream, Int64 bufferSize, IntPtr buffer, IntPtr bytesWrittenPtr) { throw new NotSupportedException(); } ////// Commit changes. /// ////// Only relevant to transacted streams. /// void IStream.Commit(Int32 flags) { throw new NotSupportedException(); } ////// Lock at most byteCount bytes starting at offset. /// ////// Not supported by System.IO.Stream. /// void IStream.LockRegion(Int64 offset, Int64 byteCount, Int32 lockType) { throw new NotSupportedException(); } ////// Undo writes performed since last Commit. /// ////// Relevant only to transacted streams. /// void IStream.Revert() { throw new NotSupportedException(); } ////// Unlock the specified region. /// ////// Not supported by System.IO.Stream. /// void IStream.UnlockRegion(Int64 offset, Int64 byteCount, Int32 lockType) { throw new NotSupportedException(); } #endregion Unimplemented methods #region Fields private Stream _ioStream; #endregion Fields } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved.
Link Menu

This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- Dynamic.cs
- DataObjectAttribute.cs
- PtsCache.cs
- QilInvokeLateBound.cs
- HostProtectionPermission.cs
- StylusPointCollection.cs
- DataServiceRequestException.cs
- CellParagraph.cs
- ItemContainerProviderWrapper.cs
- DataAdapter.cs
- EventBookmark.cs
- DesignerOptionService.cs
- HostAdapter.cs
- CodeGotoStatement.cs
- CompilerLocalReference.cs
- CharEnumerator.cs
- ServicePointManagerElement.cs
- ModelTreeEnumerator.cs
- ThreadPool.cs
- StyleTypedPropertyAttribute.cs
- _ScatterGatherBuffers.cs
- MenuItemStyleCollectionEditor.cs
- TreeNodeCollection.cs
- PixelFormats.cs
- AutomationFocusChangedEventArgs.cs
- DocumentViewerBase.cs
- AdCreatedEventArgs.cs
- TextEffectCollection.cs
- MessageEnumerator.cs
- IRCollection.cs
- StringReader.cs
- TableProviderWrapper.cs
- DrawingContextWalker.cs
- TextStore.cs
- StringResourceManager.cs
- DependencyObjectType.cs
- NavigationProgressEventArgs.cs
- ActivityExecutionFilter.cs
- EntityCollectionChangedParams.cs
- TraceContext.cs
- smtpconnection.cs
- HitTestDrawingContextWalker.cs
- IndexerNameAttribute.cs
- OuterGlowBitmapEffect.cs
- ListViewInsertionMark.cs
- HttpHandlersSection.cs
- ViewStateException.cs
- PrintDialog.cs
- XmlAttributeCollection.cs
- util.cs
- HasActivatableWorkflowEvent.cs
- OletxVolatileEnlistment.cs
- SchemaImporter.cs
- _LocalDataStoreMgr.cs
- AttributeEmitter.cs
- HitTestParameters3D.cs
- FileUtil.cs
- SelfIssuedAuthProofToken.cs
- AnimationClock.cs
- DbProviderSpecificTypePropertyAttribute.cs
- CreateUserErrorEventArgs.cs
- ChtmlImageAdapter.cs
- ToggleButtonAutomationPeer.cs
- DataServiceBehavior.cs
- HttpDigestClientCredential.cs
- DefaultValueConverter.cs
- DataSourceSelectArguments.cs
- altserialization.cs
- CalendarDay.cs
- UntypedNullExpression.cs
- xmlfixedPageInfo.cs
- WindowsStatusBar.cs
- LeafCellTreeNode.cs
- DigitShape.cs
- ConfigurationLocationCollection.cs
- AutomationEventArgs.cs
- MessageHeaderAttribute.cs
- AssemblyInfo.cs
- HwndHost.cs
- SecurityDocument.cs
- DefaultValueTypeConverter.cs
- SystemIPv4InterfaceProperties.cs
- MetadataFile.cs
- DateTimeConstantAttribute.cs
- XmlDownloadManager.cs
- InstalledVoice.cs
- DeferredSelectedIndexReference.cs
- FlowNode.cs
- CellTreeNode.cs
- ObjectFactoryCodeDomTreeGenerator.cs
- SecurityManager.cs
- ListBox.cs
- MappingException.cs
- ObjectComplexPropertyMapping.cs
- CommandLineParser.cs
- QilUnary.cs
- IPEndPoint.cs
- MediaPlayerState.cs
- LeafCellTreeNode.cs
- DocumentSchemaValidator.cs