From 48ae3075a5c80e75923a60d4d0ba0b56d9b08c2a Mon Sep 17 00:00:00 2001 From: Lei Zhang Date: Wed, 15 Aug 2018 18:42:32 +0000 Subject: Make CFX_MemoryStream always consecutive. 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 Commit-Queue: Lei Zhang --- core/fxcrt/cfx_memorystream.cpp | 109 +++++++++++----------------------------- core/fxcrt/cfx_memorystream.h | 14 ++---- 2 files changed, 33 insertions(+), 90 deletions(-) (limited to 'core') 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(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(offset), size); - return true; - } - - size_t nStartBlock = static_cast(offset) / kBlockSize; - offset -= static_cast(nStartBlock * kBlockSize); - while (size) { - size_t nRead = std::min(size, kBlockSize - static_cast(offset)); - memcpy(buffer, m_Blocks[nStartBlock] + offset, nRead); - buffer = static_cast(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(offset) / kBlockSize; - offset -= static_cast(nStartBlock * kBlockSize); - while (size) { - size_t nWrite = std::min(size, kBlockSize - static_cast(offset)); - memcpy(m_Blocks[nStartBlock] + offset, buffer, nWrite); - buffer = static_cast(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; } diff --git a/core/fxcrt/cfx_memorystream.h b/core/fxcrt/cfx_memorystream.h index 95f62b6a2c..47e491275c 100644 --- a/core/fxcrt/cfx_memorystream.h +++ b/core/fxcrt/cfx_memorystream.h @@ -7,8 +7,9 @@ #ifndef CORE_FXCRT_CFX_MEMORYSTREAM_H_ #define CORE_FXCRT_CFX_MEMORYSTREAM_H_ -#include +#include +#include "core/fxcrt/fx_memory.h" #include "core/fxcrt/fx_stream.h" #include "core/fxcrt/retain_ptr.h" @@ -26,24 +27,19 @@ class CFX_MemoryStream : public IFX_SeekableStream { bool WriteBlock(const void* buffer, FX_FILESIZE offset, size_t size) override; bool Flush() override; - uint8_t* GetBuffer() { - return !m_Blocks.empty() ? m_Blocks.front() : nullptr; - } + const uint8_t* GetBuffer() const { return m_data.get(); } private: - explicit CFX_MemoryStream(bool bConsecutive); + CFX_MemoryStream(); // Takes ownership of |pBuffer|. CFX_MemoryStream(uint8_t* pBuffer, size_t nSize); ~CFX_MemoryStream() override; - bool ExpandBlocks(size_t size); - - std::vector m_Blocks; + std::unique_ptr m_data; size_t m_nTotalSize; size_t m_nCurSize; size_t m_nCurPos = 0; - const bool m_bConsecutive; }; #endif // CORE_FXCRT_CFX_MEMORYSTREAM_H_ -- cgit v1.2.3