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// Copyright 2017 PDFium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
#include "core/fxcrt/cfx_memorystream.h"
#include <algorithm>
#include "core/fxcrt/fx_safe_types.h"
CFX_MemoryStream::CFX_MemoryStream() : m_nTotalSize(0), m_nCurSize(0) {}
CFX_MemoryStream::CFX_MemoryStream(uint8_t* pBuffer, size_t nSize)
: m_data(pBuffer), m_nTotalSize(nSize), m_nCurSize(nSize) {}
CFX_MemoryStream::~CFX_MemoryStream() = default;
FX_FILESIZE CFX_MemoryStream::GetSize() {
return static_cast<FX_FILESIZE>(m_nCurSize);
}
bool CFX_MemoryStream::IsEOF() {
return m_nCurPos >= static_cast<size_t>(GetSize());
}
FX_FILESIZE CFX_MemoryStream::GetPosition() {
return static_cast<FX_FILESIZE>(m_nCurPos);
}
bool CFX_MemoryStream::Flush() {
return true;
}
bool CFX_MemoryStream::ReadBlock(void* buffer,
FX_FILESIZE offset,
size_t size) {
if (!buffer || offset < 0 || !size)
return false;
FX_SAFE_SIZE_T newPos = size;
newPos += offset;
if (!newPos.IsValid() || newPos.ValueOrDefault(0) == 0 ||
newPos.ValueOrDie() > m_nCurSize) {
return false;
}
m_nCurPos = newPos.ValueOrDie();
memcpy(buffer, &GetBuffer()[offset], size);
return true;
}
size_t CFX_MemoryStream::ReadBlock(void* buffer, size_t size) {
if (m_nCurPos >= m_nCurSize)
return 0;
size_t nRead = std::min(size, m_nCurSize - m_nCurPos);
if (!ReadBlock(buffer, static_cast<int32_t>(m_nCurPos), nRead))
return 0;
return nRead;
}
bool CFX_MemoryStream::WriteBlock(const void* buffer,
FX_FILESIZE offset,
size_t size) {
if (!buffer || offset < 0 || !size)
return false;
FX_SAFE_SIZE_T safe_new_pos = size;
safe_new_pos += offset;
if (!safe_new_pos.IsValid())
return false;
size_t new_pos = safe_new_pos.ValueOrDie();
if (new_pos > m_nTotalSize) {
static constexpr size_t kBlockSize = 64 * 1024;
FX_SAFE_SIZE_T new_size = new_pos;
new_size *= 2;
new_size += (kBlockSize - 1);
new_size /= kBlockSize;
new_size *= kBlockSize;
if (!new_size.IsValid())
return false;
m_nTotalSize = new_size.ValueOrDie();
if (m_data)
m_data.reset(FX_Realloc(uint8_t, m_data.get(), m_nTotalSize));
else
m_data.reset(FX_Alloc(uint8_t, m_nTotalSize));
}
m_nCurPos = new_pos;
memcpy(&m_data.get()[offset], buffer, size);
m_nCurSize = std::max(m_nCurSize, m_nCurPos);
return true;
}
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