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 CFX_CodecMemory(size_t buffer_size)11CFX_CodecMemory::CFX_CodecMemory(size_t buffer_size) 12 : buffer_(FX_Alloc(uint8_t, buffer_size)), size_(buffer_size) {} 13 14 CFX_CodecMemory::~CFX_CodecMemory() = default; 15 Seek(size_t pos)16bool CFX_CodecMemory::Seek(size_t pos) { 17 if (pos > size_) 18 return false; 19 20 pos_ = pos; 21 return true; 22 } 23 ReadBlock(pdfium::span<uint8_t> buffer)24size_t CFX_CodecMemory::ReadBlock(pdfium::span<uint8_t> buffer) { 25 if (buffer.empty() || IsEOF()) 26 return 0; 27 28 size_t bytes_to_read = std::min(buffer.size(), size_ - pos_); 29 fxcrt::spancpy(buffer, GetBufferSpan().subspan(pos_, bytes_to_read)); 30 pos_ += bytes_to_read; 31 return bytes_to_read; 32 } 33 TryResize(size_t new_buffer_size)34bool CFX_CodecMemory::TryResize(size_t new_buffer_size) { 35 uint8_t* pOldBuf = buffer_.release(); 36 uint8_t* pNewBuf = FX_TryRealloc(uint8_t, pOldBuf, new_buffer_size); 37 if (new_buffer_size && !pNewBuf) { 38 buffer_.reset(pOldBuf); 39 return false; 40 } 41 buffer_.reset(pNewBuf); 42 size_ = new_buffer_size; 43 return true; 44 } 45 Consume(size_t consumed)46void CFX_CodecMemory::Consume(size_t consumed) { 47 fxcrt::spanmove(GetBufferSpan(), GetBufferSpan().subspan(consumed)); 48 } 49