/// <summary>
/// See .NET Framework SDK under System.IO.Stream
/// </summary>
/// <param name="buffer">Read data buffer</param>
/// <param name="offset">Buffer start position</param>
/// <param name="count">Number of bytes to read</param>
/// <returns>Number of bytes actually read</returns>
public override int Read(byte[] buffer, int offset, int count)
{
CheckDisposedStatus();
PackagingUtilities.VerifyStreamReadArgs(this, buffer, offset, count);
int read = 0;
if (0 == offset) // Zero offset is typical case
{
_safeIStream.Read(buffer, count, out read);
}
else // Non-zero offset
{
// Read into local array and then copy it into the given buffer at
// the specified offset.
byte[] localBuffer = new byte[count];
_safeIStream.Read(localBuffer, count, out read);
if (read > 0)
{
Array.Copy(localBuffer, 0, buffer, offset, read);
}
}
return(read);
}
/// <summary>
/// See .NET Framework SDK under System.IO.Stream
/// </summary>
public override int Read(byte[] buffer, int offset, int count)
{
CheckDisposed();
PackagingUtilities.VerifyStreamReadArgs(this, buffer, offset, count);
int result = InternalRead(_streamPosition, buffer, offset, count);
FlushCacheIfNecessary();
checked { _streamPosition += result; }
return(result);
}
private int ReadFromCache(SparseMemoryStream cache, long start, int count, byte[] buffer, int bufferOffset)
{
#if DEBUG
// debug only check for valid parameters, as we generally expect callers to verify them
PackagingUtilities.VerifyStreamReadArgs(this, buffer, bufferOffset, count);
#endif
Debug.Assert(cache != null);
Debug.Assert(start >= 0);
IList <MemoryStreamBlock> collection = cache.MemoryBlockCollection;
checked
{
// use BinarySearch to locate blocks of interest quickly
bool match; // exact match?
int index = FindIndexOfBlockAtOffset(cache, start, out match);
// if match was found, read from it
int bytesRead = 0;
if (match)
{
MemoryStreamBlock memStreamBlock = collection[index];
long overlapBlockOffset;
long overlapBlockSize;
// we have got an overlap which can be used to satisfy the read request,
// at least partially
PackagingUtilities.CalculateOverlap(memStreamBlock.Offset, memStreamBlock.Stream.Length,
start, count,
out overlapBlockOffset, out overlapBlockSize);
if (overlapBlockSize > 0)
{
// overlap must be starting at the start as we know for sure that
// memStreamBlock.Offset <= start
Debug.Assert(overlapBlockOffset == start);
memStreamBlock.Stream.Seek(overlapBlockOffset - memStreamBlock.Offset, SeekOrigin.Begin);
// we know that memStream will return as much data as we requested
// even if this logic changes we do not have to return everything
// a partially complete read is acceptable here
bytesRead = memStreamBlock.Stream.Read(buffer, bufferOffset, (int)overlapBlockSize);
}
}
return(bytesRead);
}
}
public override int Read(byte[] buffer, int offset, int count)
{
int num3;
this.CheckDisposed();
PackagingUtilities.VerifyStreamReadArgs(this, buffer, offset, count);
if (count == 0)
{
return(0);
}
if (this._currentStreamLength <= this._currentStreamPosition)
{
return(0);
}
int num2 = (int)Math.Min((long)count, this._currentStreamLength - this._currentStreamPosition);
if (this._isolatedStorageMode)
{
this._isolatedStorageStream.Seek(this._currentStreamPosition, SeekOrigin.Begin);
num3 = this._isolatedStorageStream.Read(buffer, offset, num2);
}
else
{
Array.Clear(buffer, offset, num2);
int num = this._memoryStreamList.BinarySearch(this.GetSearchBlockForOffset(this._currentStreamPosition));
if (num < 0)
{
num = ~num;
}
while (num < this._memoryStreamList.Count)
{
long num4;
long num5;
MemoryStreamBlock block = this._memoryStreamList[num];
PackagingUtilities.CalculateOverlap(block.Offset, (long)((int)block.Stream.Length), this._currentStreamPosition, (long)num2, out num5, out num4);
if (num4 <= 0L)
{
break;
}
Array.Copy(block.Stream.GetBuffer(), (int)(num5 - block.Offset), buffer, (int)((offset + num5) - this._currentStreamPosition), (int)num4);
num++;
}
num3 = num2;
}
this._currentStreamPosition += num3;
return(num3);
}
public override int Read(byte[] buffer, int offset, int count)
{
this.CheckDisposed();
PackagingUtilities.VerifyStreamReadArgs(this, buffer, offset, count);
if (count == 0)
{
return(0);
}
if (this._currentStreamLength <= this._currentStreamPosition)
{
return(0);
}
int num2 = 0;
int num4 = 0;
long num5 = 0L;
int num3 = 0;
long num = this._currentStreamPosition;
if (num < this._persistedSize)
{
num5 = Math.Min(this._currentStreamLength, this._persistedSize) - num;
num4 = (int)Math.Min((long)count, num5);
this._blockManager.Stream.Seek(this._persistedOffset + num, SeekOrigin.Begin);
num2 = this._blockManager.Stream.Read(buffer, offset, num4);
num += num2;
count -= num2;
offset += num2;
if (num2 < num4)
{
this._currentStreamPosition = num;
return(num2);
}
}
if ((this._sparseMemoryStreamSuffix != null) && ((num + count) > this._persistedSize))
{
this._sparseMemoryStreamSuffix.Seek(num - this._persistedSize, SeekOrigin.Begin);
num3 = this._sparseMemoryStreamSuffix.Read(buffer, offset, count);
num += num3;
}
int num6 = num2 + num3;
this._currentStreamPosition = num;
return(num6);
}
public override int Read(byte[] buffer, int offset, int count)
{
this.CheckDisposed();
PackagingUtilities.VerifyStreamReadArgs(this, buffer, offset, count);
if (count == 0)
{
return(0);
}
switch (this._mode)
{
case Mode.Start:
if (this._position != 0L)
{
this.ChangeMode(Mode.Emulation);
break;
}
this.ChangeMode(Mode.ReadPassThrough);
break;
case Mode.WritePassThrough:
if (this._position != 0L)
{
this.ChangeMode(Mode.Emulation);
break;
}
this.ChangeMode(Mode.ReadPassThrough);
break;
}
if (this._current == null)
{
return(0);
}
int num = this._current.Read(buffer, offset, count);
if ((this._mode == Mode.ReadPassThrough) && (num == 0))
{
this.UpdateUncompressedDataLength(this._position);
this.ChangeMode(Mode.Start);
}
this._position += num;
return(num);
}
override public int Read(byte[] buffer, int offset, int count)
{
CheckDisposed();
PackagingUtilities.VerifyStreamReadArgs(this, buffer, offset, count);
Debug.Assert(_cachePrefixStream == null); // we only expect this thing to be not null during Archive Save execution
// that would between PreSaveNotofication call and Save SaveStreaming
Debug.Assert(_currentStreamPosition >= 0);
if (count == 0)
{
return(0);
}
if (_currentStreamLength <= _currentStreamPosition)
{
// we are past the end of the stream so let's just return 0
return(0);
}
int totalBytesRead;
int diskBytesRead = 0;
int diskBytesToRead = 0;
long persistedTailSize = 0;
int memoryBytesRead = 0;
long newStreamPosition = _currentStreamPosition;
checked
{
// Try to satisfy request with the Read from the Disk
if (newStreamPosition < _persistedSize)
{
// we have at least partial overlap between request and the data on disk
//first let's get min between size of the stream's tail and the tail of the persisted chunk
// in some cases stream might be smaller
// e.g. _currentStreamLength < _persistedSize, if let's say stream was truncated
persistedTailSize = Math.Min(_currentStreamLength, _persistedSize) - newStreamPosition;
Debug.Assert(persistedTailSize > 0);
// we also do not want to read more data than was requested by the user
diskBytesToRead = (int)Math.Min((long)count, persistedTailSize); // this is a safe cast as count has int type
Debug.Assert(diskBytesToRead > 0);
// and now we can actually read it
_blockManager.Stream.Seek(_persistedOffset + newStreamPosition, SeekOrigin.Begin);
// we are ready for getting fewer bytes than reqested
diskBytesRead = _blockManager.Stream.Read(buffer, offset, diskBytesToRead);
newStreamPosition += diskBytesRead;
count -= diskBytesRead;
offset += diskBytesRead;
if (diskBytesRead < diskBytesToRead)
{
// we didn't everything that we hae asked for. In such case we shouldn't
// try to get data from the _sparseMemoryStreamSuffix
_currentStreamPosition = newStreamPosition;
return(diskBytesRead);
}
}
// check whether we need to get data from the memory Stream;
if ((_sparseMemoryStreamSuffix != null) && (newStreamPosition + count > _persistedSize))
{
// we are either trying to finish the request partially satisfied by the
// on disk data or the read is entirely within the suffix
_sparseMemoryStreamSuffix.Seek(newStreamPosition - _persistedSize, SeekOrigin.Begin);
memoryBytesRead = _sparseMemoryStreamSuffix.Read(buffer, offset, count);
newStreamPosition += memoryBytesRead;
}
totalBytesRead = diskBytesRead + memoryBytesRead;
}
_currentStreamPosition = newStreamPosition;
return(totalBytesRead);
}
