1 // Copyright 2018 The PDFium Authors 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "core/fxcodec/cfx_codec_memory.h" 6 7 #include <algorithm> 8 9 #include "core/fxcrt/span_util.h" 10 #include "core/fxcrt/stl_util.h" 11 CFX_CodecMemory(size_t buffer_size)12CFX_CodecMemory::CFX_CodecMemory(size_t buffer_size) 13 : buffer_(FX_Alloc(uint8_t, buffer_size)), size_(buffer_size) {} 14 15 CFX_CodecMemory::~CFX_CodecMemory() = default; 16 Seek(size_t pos)17bool CFX_CodecMemory::Seek(size_t pos) { 18 if (pos > size_) 19 return false; 20 21 pos_ = pos; 22 return true; 23 } 24 ReadBlock(pdfium::span<uint8_t> buffer)25size_t CFX_CodecMemory::ReadBlock(pdfium::span<uint8_t> buffer) { 26 if (buffer.empty() || IsEOF()) 27 return 0; 28 29 size_t bytes_to_read = std::min(buffer.size(), size_ - pos_); 30 fxcrt::Copy(GetBufferSpan().subspan(pos_, bytes_to_read), buffer); 31 pos_ += bytes_to_read; 32 return bytes_to_read; 33 } 34 TryResize(size_t new_buffer_size)35bool CFX_CodecMemory::TryResize(size_t new_buffer_size) { 36 uint8_t* pOldBuf = buffer_.release(); 37 uint8_t* pNewBuf = FX_TryRealloc(uint8_t, pOldBuf, new_buffer_size); 38 if (new_buffer_size && !pNewBuf) { 39 buffer_.reset(pOldBuf); 40 return false; 41 } 42 buffer_.reset(pNewBuf); 43 size_ = new_buffer_size; 44 return true; 45 } 46 Consume(size_t consumed)47void CFX_CodecMemory::Consume(size_t consumed) { 48 fxcrt::spanmove(GetBufferSpan(), GetBufferSpan().subspan(consumed)); 49 } 50