tor-browser

render_pipeline.h (5019B)

---

// Copyright (c) the JPEG XL Project Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#ifndef LIB_JXL_RENDER_PIPELINE_RENDER_PIPELINE_H_
#define LIB_JXL_RENDER_PIPELINE_RENDER_PIPELINE_H_

#include <jxl/memory_manager.h>

#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <memory>
#include <utility>
#include <vector>

#include "lib/jxl/base/rect.h"
#include "lib/jxl/base/status.h"
#include "lib/jxl/frame_dimensions.h"
#include "lib/jxl/image.h"
#include "lib/jxl/render_pipeline/render_pipeline_stage.h"

namespace jxl {

// Interface to provide input to the rendering pipeline. When this object is
// destroyed, all the data in the provided ImageF's Rects must have been
// initialized.
class RenderPipelineInput {
public:
 RenderPipelineInput(const RenderPipelineInput&) = delete;
 RenderPipelineInput(RenderPipelineInput&& other) noexcept {
   *this = std::move(other);
 }
 RenderPipelineInput& operator=(RenderPipelineInput&& other) noexcept {
   pipeline_ = other.pipeline_;
   group_id_ = other.group_id_;
   thread_id_ = other.thread_id_;
   buffers_ = std::move(other.buffers_);
   other.pipeline_ = nullptr;
   return *this;
 }

 RenderPipelineInput() = default;
 Status Done();

 const std::pair<ImageF*, Rect>& GetBuffer(size_t c) const {
   JXL_DASSERT(c < buffers_.size());
   return buffers_[c];
 }

private:
 RenderPipeline* pipeline_ = nullptr;
 size_t group_id_;
 size_t thread_id_;
 std::vector<std::pair<ImageF*, Rect>> buffers_;
 friend class RenderPipeline;
};

class RenderPipeline {
public:
 class Builder {
  public:
   explicit Builder(JxlMemoryManager* memory_manager, size_t num_c)
       : memory_manager_(memory_manager), num_c_(num_c) {
     JXL_DASSERT(num_c > 0);
   }

   // Adds a stage to the pipeline. Must be called at least once; the last
   // added stage cannot have kInOut channels.
   Status AddStage(std::unique_ptr<RenderPipelineStage> stage);

   // Enables using the simple (i.e. non-memory-efficient) implementation of
   // the pipeline.
   void UseSimpleImplementation() { use_simple_implementation_ = true; }

   // Finalizes setup of the pipeline. Shifts for all channels should be 0 at
   // this point.
   StatusOr<std::unique_ptr<RenderPipeline>> Finalize(
       FrameDimensions frame_dimensions) &&;

  private:
   JxlMemoryManager* memory_manager_;
   std::vector<std::unique_ptr<RenderPipelineStage>> stages_;
   size_t num_c_;
   bool use_simple_implementation_ = false;
 };

 friend class Builder;

 virtual ~RenderPipeline() = default;

 Status IsInitialized() const {
   for (const auto& stage : stages_) {
     JXL_RETURN_IF_ERROR(stage->IsInitialized());
   }
   return true;
 }

 // Allocates storage to run with `num` threads. If `use_group_ids` is true,
 // storage is allocated for each group, not each thread. The behaviour is
 // undefined if calling this function multiple times with a different value
 // for `use_group_ids`.
 Status PrepareForThreads(size_t num, bool use_group_ids);

 // Retrieves a buffer where input data should be stored by the callee. When
 // input has been provided for all buffers, the pipeline will complete its
 // processing. This method may be called multiple times concurrently from
 // different threads, provided that a different `thread_id` is given.
 RenderPipelineInput GetInputBuffers(size_t group_id, size_t thread_id);

 size_t PassesWithAllInput() const {
   return *std::min_element(group_completed_passes_.begin(),
                            group_completed_passes_.end());
 }

 virtual void ClearDone(size_t i) {}

protected:
 explicit RenderPipeline(JxlMemoryManager* memory_manager)
     : memory_manager_(memory_manager) {}
 JxlMemoryManager* memory_manager_;

 std::vector<std::unique_ptr<RenderPipelineStage>> stages_;
 // Shifts for every channel at the input of each stage.
 std::vector<std::vector<std::pair<size_t, size_t>>> channel_shifts_;

 // Amount of (cumulative) padding required by each stage and channel, in
 // either direction.
 std::vector<std::vector<std::pair<size_t, size_t>>> padding_;

 FrameDimensions frame_dimensions_;

 std::vector<uint8_t> group_completed_passes_;

 friend class RenderPipelineInput;

private:
 Status InputReady(size_t group_id, size_t thread_id,
                   const std::vector<std::pair<ImageF*, Rect>>& buffers);

 virtual std::vector<std::pair<ImageF*, Rect>> PrepareBuffers(
     size_t group_id, size_t thread_id) = 0;

 virtual Status ProcessBuffers(size_t group_id, size_t thread_id) = 0;

 // Note that this method may be called multiple times with different (or
 // equal) `num`.
 virtual Status PrepareForThreadsInternal(size_t num, bool use_group_ids) = 0;

 // Called once frame dimensions and stages are known.
 virtual Status Init() { return true; }
};

}  // namespace jxl

#endif  // LIB_JXL_RENDER_PIPELINE_RENDER_PIPELINE_H_