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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
// ---------------------------------------------------------------------------
//
// Buffer.cpp
// ---------------------------------------------------------------------------
#include "stdafx.h"
#include "sbuffer.h"
#include "ex.h"
#include "holder.h"
#include "stdmacros.h"
// Try to minimize the performance impact of contracts on CHK build.
#if defined(_MSC_VER)
#pragma inline_depth (20)
#endif
const DWORD g_garbageFillBuffer[GARBAGE_FILL_BUFFER_ITEMS] =
{
GARBAGE_FILL_DWORD, GARBAGE_FILL_DWORD, GARBAGE_FILL_DWORD, GARBAGE_FILL_DWORD,
GARBAGE_FILL_DWORD, GARBAGE_FILL_DWORD, GARBAGE_FILL_DWORD, GARBAGE_FILL_DWORD,
GARBAGE_FILL_DWORD, GARBAGE_FILL_DWORD, GARBAGE_FILL_DWORD, GARBAGE_FILL_DWORD,
GARBAGE_FILL_DWORD, GARBAGE_FILL_DWORD, GARBAGE_FILL_DWORD, GARBAGE_FILL_DWORD,
};
//----------------------------------------------------------------------------
// ReallocateBuffer
// Low level buffer reallocate routine
//----------------------------------------------------------------------------
void SBuffer::ReallocateBuffer(COUNT_T allocation, Preserve preserve)
{
CONTRACT_VOID
{
PRECONDITION(CheckPointer(this));
PRECONDITION(CheckBufferClosed());
PRECONDITION(CheckAllocation(allocation));
PRECONDITION(allocation >= m_size);
POSTCONDITION(m_allocation == allocation);
if (allocation > 0) THROWS; else NOTHROW;
GC_NOTRIGGER;
SUPPORTS_DAC_HOST_ONLY;
}
CONTRACT_END;
BYTE *newBuffer = NULL;
if (allocation > 0)
{
newBuffer = NewBuffer(allocation);
if (preserve == PRESERVE)
{
// Copy the relevant contents of the old buffer over
DebugMoveBuffer(newBuffer, m_buffer, m_size);
}
}
if (IsAllocated())
DeleteBuffer(m_buffer, m_allocation);
m_buffer = newBuffer;
m_allocation = allocation;
if (allocation > 0)
SetAllocated();
else
ClearAllocated();
ClearImmutable();
RETURN;
}
void SBuffer::Replace(const Iterator &i, COUNT_T deleteSize, COUNT_T insertSize)
{
CONTRACT_VOID
{
THROWS;
GC_NOTRIGGER;
PRECONDITION(CheckPointer(this));
PRECONDITION(CheckIteratorRange(i, deleteSize));
SUPPORTS_DAC_HOST_ONLY;
}
CONTRACT_END;
COUNT_T startRange = (COUNT_T) (i.m_ptr - m_buffer);
// The PRECONDITION(CheckIterationRange(i, deleteSize)) should check this in
// contract-checking builds, but this ensures we don't integer overflow if someone
// passes in an aggregious deleteSize by capping it to the remaining length in the
// buffer.
if ((COUNT_T)(m_buffer + m_size - i.m_ptr) < deleteSize)
{
_ASSERTE(!"Trying to replace more bytes than are remaining in the buffer.");
deleteSize = (COUNT_T)(m_buffer + m_size - i.m_ptr);
}
COUNT_T endRange = startRange + deleteSize;
COUNT_T end = m_size;
SCOUNT_T delta = insertSize - deleteSize;
if (delta < 0)
{
// Buffer is shrinking
DebugDestructBuffer(i.m_ptr, deleteSize);
DebugMoveBuffer(m_buffer + endRange + delta,
m_buffer + endRange,
end - endRange);
Resize(m_size+delta, PRESERVE);
i.Resync(this, m_buffer + startRange);
}
else if (delta > 0)
{
// Buffer is growing
ResizePadded(m_size+delta);
i.Resync(this, m_buffer + startRange);
DebugDestructBuffer(i.m_ptr, deleteSize);
DebugMoveBuffer(m_buffer + endRange + delta,
m_buffer + endRange,
end - endRange);
}
else
{
// Buffer stays the same size. We need to DebugDestruct it first to keep
// the invariant that the new space is clean.
DebugDestructBuffer(i.m_ptr, insertSize);
}
DebugConstructBuffer(i.m_ptr, insertSize);
RETURN;
}
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