40cd26fdbc
TBR=rsesek Bug: 926235 Change-Id: Ibaf250d761cc5f0fc5e334319c12ecb09f7e69c6 Reviewed-on: https://chromium-review.googlesource.com/c/1461320 Commit-Queue: Nico Weber <thakis@chromium.org> Auto-Submit: Nico Weber <thakis@chromium.org> Reviewed-by: Scott Violet <sky@chromium.org> Cr-Commit-Position: refs/heads/master@{#630638}
125 lines
3.4 KiB
C++
125 lines
3.4 KiB
C++
// Copyright (c) 2010 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef PDF_CHUNK_STREAM_H_
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#define PDF_CHUNK_STREAM_H_
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#include <stddef.h>
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#include <string.h>
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#include <algorithm>
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#include <array>
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#include <memory>
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#include <utility>
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#include <vector>
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#include "pdf/range_set.h"
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namespace chrome_pdf {
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// This class collects a chunks of data into one data stream. Client can check
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// if data in certain range is available, and get missing chunks of data.
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template <uint32_t N>
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class ChunkStream {
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public:
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static constexpr uint32_t kChunkSize = N;
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using ChunkData = typename std::array<unsigned char, N>;
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ChunkStream() {}
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~ChunkStream() {}
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void SetChunkData(uint32_t chunk_index, std::unique_ptr<ChunkData> data) {
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if (!data)
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return;
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if (chunk_index >= data_.size())
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data_.resize(chunk_index + 1);
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if (!data_[chunk_index])
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++filled_chunks_count_;
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data_[chunk_index] = std::move(data);
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filled_chunks_.Union(gfx::Range(chunk_index, chunk_index + 1));
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}
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bool ReadData(const gfx::Range& range, void* buffer) const {
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if (!IsRangeAvailable(range))
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return false;
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unsigned char* data_buffer = static_cast<unsigned char*>(buffer);
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uint32_t start = range.start();
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while (start != range.end()) {
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const uint32_t chunk_index = GetChunkIndex(start);
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const uint32_t chunk_start = start % kChunkSize;
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const uint32_t len =
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std::min(kChunkSize - chunk_start, range.end() - start);
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memcpy(data_buffer, data_[chunk_index]->data() + chunk_start, len);
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data_buffer += len;
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start += len;
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}
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return true;
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}
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uint32_t GetChunkIndex(uint32_t offset) const { return offset / kChunkSize; }
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gfx::Range GetChunksRange(uint32_t offset, uint32_t size) const {
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return gfx::Range(GetChunkIndex(offset), GetChunkEnd(offset + size));
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}
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bool IsRangeAvailable(const gfx::Range& range) const {
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if (!range.IsValid() || range.is_reversed() ||
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(eof_pos_ > 0 && eof_pos_ < range.end())) {
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return false;
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}
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if (range.is_empty())
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return true;
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const gfx::Range chunks_range(GetChunkIndex(range.start()),
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GetChunkEnd(range.end()));
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return filled_chunks_.Contains(chunks_range);
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}
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bool IsChunkAvailable(uint32_t chunk_index) const {
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return filled_chunks_.Contains(chunk_index);
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}
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void set_eof_pos(uint32_t eof_pos) { eof_pos_ = eof_pos; }
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uint32_t eof_pos() const { return eof_pos_; }
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const RangeSet& filled_chunks() const { return filled_chunks_; }
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bool IsComplete() const {
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return eof_pos_ > 0 && IsRangeAvailable(gfx::Range(0, eof_pos_));
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}
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bool IsValidChunkIndex(uint32_t chunk_index) const {
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return !eof_pos_ || (chunk_index <= GetChunkIndex(eof_pos_ - 1));
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}
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void Clear() {
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data_.clear();
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eof_pos_ = 0;
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filled_chunks_.Clear();
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filled_chunks_count_ = 0;
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}
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uint32_t filled_chunks_count() const { return filled_chunks_count_; }
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uint32_t total_chunks_count() const { return GetChunkEnd(eof_pos_); }
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private:
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uint32_t GetChunkEnd(uint32_t offset) const {
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return (offset + kChunkSize - 1) / kChunkSize;
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}
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std::vector<std::unique_ptr<ChunkData>> data_;
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uint32_t eof_pos_ = 0;
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RangeSet filled_chunks_;
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uint32_t filled_chunks_count_ = 0;
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};
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} // namespace chrome_pdf
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#endif // PDF_CHUNK_STREAM_H_
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