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authorLei Zhang <thestig@chromium.org>2018-08-15 18:42:32 +0000
committerChromium commit bot <commit-bot@chromium.org>2018-08-15 18:42:32 +0000
commit48ae3075a5c80e75923a60d4d0ba0b56d9b08c2a (patch)
tree464540a6b17b7e2cc3096d7f579729745f5b0664 /core/fxcrt/cfx_memorystream.cpp
parent55ccb526913debb3269a33792bbd61b05656ec46 (diff)
downloadpdfium-48ae3075a5c80e75923a60d4d0ba0b56d9b08c2a.tar.xz
Make CFX_MemoryStream always consecutive.chromium/3524
Non-consecutive mode has questionable correctness and is not an obvious performance win. Change-Id: Idaa66e5ee5c4604628a0f55b67d5a04ab47ea5ec Reviewed-on: https://pdfium-review.googlesource.com/40050 Reviewed-by: Tom Sepez <tsepez@chromium.org> Commit-Queue: Lei Zhang <thestig@chromium.org>
Diffstat (limited to 'core/fxcrt/cfx_memorystream.cpp')
-rw-r--r--core/fxcrt/cfx_memorystream.cpp109
1 files changed, 28 insertions, 81 deletions
diff --git a/core/fxcrt/cfx_memorystream.cpp b/core/fxcrt/cfx_memorystream.cpp
index b0a0bd91d1..d64d2a0b43 100644
--- a/core/fxcrt/cfx_memorystream.cpp
+++ b/core/fxcrt/cfx_memorystream.cpp
@@ -10,24 +10,12 @@
#include "core/fxcrt/fx_safe_types.h"
-namespace {
-
-constexpr size_t kBlockSize = 64 * 1024;
-
-} // namespace
-
-CFX_MemoryStream::CFX_MemoryStream(bool bConsecutive)
- : m_nTotalSize(0), m_nCurSize(0), m_bConsecutive(bConsecutive) {}
+CFX_MemoryStream::CFX_MemoryStream() : m_nTotalSize(0), m_nCurSize(0) {}
CFX_MemoryStream::CFX_MemoryStream(uint8_t* pBuffer, size_t nSize)
- : m_nTotalSize(nSize), m_nCurSize(nSize), m_bConsecutive(true) {
- m_Blocks.push_back(pBuffer);
-}
+ : m_data(pBuffer), m_nTotalSize(nSize), m_nCurSize(nSize) {}
-CFX_MemoryStream::~CFX_MemoryStream() {
- for (uint8_t* pBlock : m_Blocks)
- FX_Free(pBlock);
-}
+CFX_MemoryStream::~CFX_MemoryStream() = default;
FX_FILESIZE CFX_MemoryStream::GetSize() {
return static_cast<FX_FILESIZE>(m_nCurSize);
@@ -48,7 +36,7 @@ bool CFX_MemoryStream::Flush() {
bool CFX_MemoryStream::ReadBlock(void* buffer,
FX_FILESIZE offset,
size_t size) {
- if (!buffer || !size || offset < 0)
+ if (!buffer || offset < 0 || !size)
return false;
FX_SAFE_SIZE_T newPos = size;
@@ -59,21 +47,7 @@ bool CFX_MemoryStream::ReadBlock(void* buffer,
}
m_nCurPos = newPos.ValueOrDie();
- if (m_bConsecutive) {
- memcpy(buffer, m_Blocks[0] + static_cast<size_t>(offset), size);
- return true;
- }
-
- size_t nStartBlock = static_cast<size_t>(offset) / kBlockSize;
- offset -= static_cast<FX_FILESIZE>(nStartBlock * kBlockSize);
- while (size) {
- size_t nRead = std::min(size, kBlockSize - static_cast<size_t>(offset));
- memcpy(buffer, m_Blocks[nStartBlock] + offset, nRead);
- buffer = static_cast<uint8_t*>(buffer) + nRead;
- size -= nRead;
- ++nStartBlock;
- offset = 0;
- }
+ memcpy(buffer, &GetBuffer()[offset], size);
return true;
}
@@ -91,62 +65,35 @@ size_t CFX_MemoryStream::ReadBlock(void* buffer, size_t size) {
bool CFX_MemoryStream::WriteBlock(const void* buffer,
FX_FILESIZE offset,
size_t size) {
- if (!buffer || !size)
+ if (!buffer || offset < 0 || !size)
return false;
- if (m_bConsecutive) {
- FX_SAFE_SIZE_T newPos = size;
- newPos += offset;
- if (!newPos.IsValid())
- return false;
-
- m_nCurPos = newPos.ValueOrDie();
- if (m_nCurPos > m_nTotalSize) {
- m_nTotalSize = (m_nCurPos + kBlockSize - 1) / kBlockSize * kBlockSize;
- if (m_Blocks.empty())
- m_Blocks.push_back(FX_Alloc(uint8_t, m_nTotalSize));
- else
- m_Blocks[0] = FX_Realloc(uint8_t, m_Blocks[0], m_nTotalSize);
- }
+ FX_SAFE_SIZE_T safe_new_pos = size;
+ safe_new_pos += offset;
+ if (!safe_new_pos.IsValid())
+ return false;
- memcpy(m_Blocks[0] + offset, buffer, size);
- m_nCurSize = std::max(m_nCurSize, m_nCurPos);
+ 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;
- return true;
+ 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;
- FX_SAFE_SIZE_T newPos = size;
- newPos += offset;
- if (!newPos.IsValid())
- return false;
- if (!ExpandBlocks(newPos.ValueOrDie()))
- return false;
+ memcpy(&m_data.get()[offset], buffer, size);
+ m_nCurSize = std::max(m_nCurSize, m_nCurPos);
- m_nCurPos = newPos.ValueOrDie();
- size_t nStartBlock = static_cast<size_t>(offset) / kBlockSize;
- offset -= static_cast<FX_FILESIZE>(nStartBlock * kBlockSize);
- while (size) {
- size_t nWrite = std::min(size, kBlockSize - static_cast<size_t>(offset));
- memcpy(m_Blocks[nStartBlock] + offset, buffer, nWrite);
- buffer = static_cast<const uint8_t*>(buffer) + nWrite;
- size -= nWrite;
- ++nStartBlock;
- offset = 0;
- }
- return true;
-}
-
-bool CFX_MemoryStream::ExpandBlocks(size_t size) {
- m_nCurSize = std::max(m_nCurSize, size);
- if (size <= m_nTotalSize)
- return true;
-
- size = (size - m_nTotalSize + kBlockSize - 1) / kBlockSize;
- size_t iCount = m_Blocks.size();
- m_Blocks.resize(iCount + size);
- while (size--) {
- m_Blocks[iCount++] = FX_Alloc(uint8_t, kBlockSize);
- m_nTotalSize += kBlockSize;
- }
return true;
}