| // Copyright 2022 The PDFium Authors |
| // 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_read_only_span_stream.h" |
| |
| #include "core/fxcrt/fx_safe_types.h" |
| #include "core/fxcrt/span_util.h" |
| #include "third_party/base/numerics/safe_conversions.h" |
| |
| CFX_ReadOnlySpanStream::CFX_ReadOnlySpanStream(pdfium::span<const uint8_t> span) |
| : span_(span) {} |
| |
| CFX_ReadOnlySpanStream::~CFX_ReadOnlySpanStream() = default; |
| |
| FX_FILESIZE CFX_ReadOnlySpanStream::GetSize() { |
| return pdfium::base::checked_cast<FX_FILESIZE>(span_.size()); |
| } |
| |
| bool CFX_ReadOnlySpanStream::ReadBlockAtOffset(pdfium::span<uint8_t> buffer, |
| FX_FILESIZE offset) { |
| if (buffer.empty() || offset < 0) |
| return false; |
| |
| FX_SAFE_SIZE_T pos = buffer.size(); |
| pos += offset; |
| if (!pos.IsValid() || pos.ValueOrDie() > span_.size()) |
| return false; |
| |
| fxcrt::spancpy( |
| buffer, |
| span_.subspan(pdfium::base::checked_cast<size_t>(offset), buffer.size())); |
| return true; |
| } |