1 files changed, 277 insertions, 0 deletions
diff --git a/gfx/2d/DrawEventRecorder.h b/gfx/2d/DrawEventRecorder.h
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+++ b/gfx/2d/DrawEventRecorder.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MOZILLA_GFX_DRAWEVENTRECORDER_H_
+#define MOZILLA_GFX_DRAWEVENTRECORDER_H_
+
+#include "2D.h"
+#include "RecordedEvent.h"
+#include "RecordingTypes.h"
+
+#include <unordered_set>
+#include <unordered_map>
+#include <functional>
+#include <vector>
+
+#include "mozilla/DataMutex.h"
+#include "mozilla/ThreadSafeWeakPtr.h"
+#include "nsTHashSet.h"
+
+namespace mozilla {
+namespace gfx {
+
+class PathRecording;
+
+class DrawEventRecorderPrivate : public DrawEventRecorder {
+ public:
+  MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(DrawEventRecorderPrivate, override)
+
+  DrawEventRecorderPrivate();
+  virtual ~DrawEventRecorderPrivate() = default;
+  bool Finish() override {
+    ClearResources();
+    return true;
+  }
+  virtual void FlushItem(IntRect) {}
+  void DetachResources() {
+    std::unordered_set<ScaledFont*> fonts;
+    fonts.swap(mStoredFonts);
+    std::for_each(fonts.begin(), fonts.end(), [this](auto font) {
+      font->RemoveUserData(reinterpret_cast<UserDataKey*>(this));
+    });
+
+    // SourceSurfaces can be deleted off the main thread, so we use
+    // ThreadSafeWeakPtrs to allow for this. RemoveUserData is thread safe.
+    std::unordered_map<void*, ThreadSafeWeakPtr<SourceSurface>> surfaces;
+    surfaces.swap(mStoredSurfaces);
+    std::for_each(surfaces.begin(), surfaces.end(), [this](auto surfacePair) {
+      RefPtr<SourceSurface> strongRef(surfacePair.second);
+      if (strongRef) {
+        strongRef->RemoveUserData(reinterpret_cast<UserDataKey*>(this));
+      }
+    });
+
+    // Now that we've detached we can't get any more pending deletions, so
+    // processing now should mean we include all clean up operations.
+    ProcessPendingDeletions();
+  }
+
+  void ClearResources() {
+    mStoredObjects.clear();
+    mStoredFontData.clear();
+    mScaledFonts.clear();
+  }
+
+  template <class S>
+  void WriteHeader(S& aStream) {
+    WriteElement(aStream, kMagicInt);
+    WriteElement(aStream, kMajorRevision);
+    WriteElement(aStream, kMinorRevision);
+  }
+
+  virtual void RecordEvent(const RecordedEvent& aEvent) = 0;
+
+  void AddStoredObject(const ReferencePtr aObject) {
+    ProcessPendingDeletions();
+    mStoredObjects.insert(aObject);
+  }
+
+  /**
+   * This is a combination of HasStoredObject and AddStoredObject, so that we
+   * only have to call ProcessPendingDeletions once, which involves locking.
+   * @param aObject the object to store if not already stored
+   * @return true if the object was not already stored, false if it was
+   */
+  bool TryAddStoredObject(const ReferencePtr aObject) {
+    ProcessPendingDeletions();
+    if (mStoredObjects.find(aObject) != mStoredObjects.end()) {
+      return false;
+    }
+
+    mStoredObjects.insert(aObject);
+    return true;
+  }
+
+  void AddPendingDeletion(std::function<void()>&& aPendingDeletion) {
+    auto lockedPendingDeletions = mPendingDeletions.Lock();
+    lockedPendingDeletions->emplace_back(std::move(aPendingDeletion));
+  }
+
+  void RemoveStoredObject(const ReferencePtr aObject) {
+    mStoredObjects.erase(aObject);
+  }
+
+  /**
+   * @param aUnscaledFont the UnscaledFont to increment the reference count for
+   * @return the previous reference count
+   */
+  int32_t IncrementUnscaledFontRefCount(const ReferencePtr aUnscaledFont) {
+    int32_t& count = mUnscaledFontRefs[aUnscaledFont];
+    return count++;
+  }
+
+  /**
+   * Decrements the reference count for aUnscaledFont and, if count is now zero,
+   * records its destruction.
+   * @param aUnscaledFont the UnscaledFont to decrement the reference count for
+   */
+  void DecrementUnscaledFontRefCount(const ReferencePtr aUnscaledFont);
+
+  void AddScaledFont(ScaledFont* aFont) {
+    if (mStoredFonts.insert(aFont).second && WantsExternalFonts()) {
+      mScaledFonts.push_back(aFont);
+    }
+  }
+
+  void RemoveScaledFont(ScaledFont* aFont) { mStoredFonts.erase(aFont); }
+
+  void AddSourceSurface(SourceSurface* aSurface) {
+    mStoredSurfaces.emplace(aSurface, aSurface);
+  }
+
+  void RemoveSourceSurface(SourceSurface* aSurface) {
+    mStoredSurfaces.erase(aSurface);
+  }
+
+#if defined(DEBUG)
+  // Only used within debug assertions.
+  bool HasStoredObject(const ReferencePtr aObject) {
+    ProcessPendingDeletions();
+    return mStoredObjects.find(aObject) != mStoredObjects.end();
+  }
+#endif
+
+  void AddStoredFontData(const uint64_t aFontDataKey) {
+    mStoredFontData.insert(aFontDataKey);
+  }
+
+  bool HasStoredFontData(const uint64_t aFontDataKey) {
+    return mStoredFontData.find(aFontDataKey) != mStoredFontData.end();
+  }
+
+  bool WantsExternalFonts() const { return mExternalFonts; }
+
+  void TakeExternalSurfaces(std::vector<RefPtr<SourceSurface>>& aSurfaces) {
+    aSurfaces = std::move(mExternalSurfaces);
+  }
+
+  virtual void StoreSourceSurfaceRecording(SourceSurface* aSurface,
+                                           const char* aReason);
+
+  /**
+   * Used when a source surface is destroyed, aSurface is a void* instead of a
+   * SourceSurface* because this is called during the SourceSurface destructor,
+   * so it is partially destructed and should not be accessed.
+   * @param aSurface the surface whose destruction is being recorded
+   */
+  void RecordSourceSurfaceDestruction(void* aSurface);
+
+  virtual void AddDependentSurface(uint64_t aDependencyId) {
+    MOZ_CRASH("GFX: AddDependentSurface");
+  }
+
+ protected:
+  void StoreExternalSurfaceRecording(SourceSurface* aSurface, uint64_t aKey);
+
+  void ProcessPendingDeletions() {
+    MOZ_ASSERT(NS_IsMainThread());
+
+    PendingDeletionsVector pendingDeletions;
+    {
+      auto lockedPendingDeletions = mPendingDeletions.Lock();
+      pendingDeletions.swap(*lockedPendingDeletions);
+    }
+    for (const auto& pendingDeletion : pendingDeletions) {
+      pendingDeletion();
+    }
+  }
+
+  virtual void Flush() = 0;
+
+  std::unordered_set<const void*> mStoredObjects;
+
+  using PendingDeletionsVector = std::vector<std::function<void()>>;
+  DataMutex<PendingDeletionsVector> mPendingDeletions{
+      "DrawEventRecorderPrivate::mPendingDeletions"};
+
+  // It's difficult to track the lifetimes of UnscaledFonts directly, so we
+  // instead track the number of recorded ScaledFonts that hold a reference to
+  // an Unscaled font and use that as a proxy to the real lifetime. An
+  // UnscaledFonts lifetime could be longer than this, but we only use the
+  // ScaledFonts directly and if another uses an UnscaledFont we have destroyed
+  // on the translation side, it will be recreated.
+  std::unordered_map<const void*, int32_t> mUnscaledFontRefs;
+
+  std::unordered_set<uint64_t> mStoredFontData;
+  std::unordered_set<ScaledFont*> mStoredFonts;
+  std::vector<RefPtr<ScaledFont>> mScaledFonts;
+
+  // SourceSurfaces can get deleted off the main thread, so we hold a map of the
+  // raw pointer to a ThreadSafeWeakPtr to protect against this.
+  std::unordered_map<void*, ThreadSafeWeakPtr<SourceSurface>> mStoredSurfaces;
+  std::vector<RefPtr<SourceSurface>> mExternalSurfaces;
+  bool mExternalFonts;
+};
+
+typedef std::function<void(MemStream& aStream,
+                           std::vector<RefPtr<ScaledFont>>& aScaledFonts)>
+    SerializeResourcesFn;
+
+// WARNING: This should not be used in its existing state because
+// it is likely to OOM because of large continguous allocations.
+class DrawEventRecorderMemory : public DrawEventRecorderPrivate {
+ public:
+  MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(DrawEventRecorderMemory, override)
+
+  /**
+   * Constructs a DrawEventRecorder that stores the recording in memory.
+   */
+  DrawEventRecorderMemory();
+  explicit DrawEventRecorderMemory(const SerializeResourcesFn& aSerialize);
+
+  void RecordEvent(const RecordedEvent& aEvent) override;
+
+  void AddDependentSurface(uint64_t aDependencyId) override;
+
+  nsTHashSet<uint64_t>&& TakeDependentSurfaces();
+
+  /**
+   * @return the current size of the recording (in chars).
+   */
+  size_t RecordingSize();
+
+  /**
+   * Wipes the internal recording buffer, but the recorder does NOT forget which
+   * objects it has recorded. This can be used so that a recording can be copied
+   * and processed in chunks, releasing memory as it goes.
+   */
+  void WipeRecording();
+  bool Finish() override;
+  void FlushItem(IntRect) override;
+
+  MemStream mOutputStream;
+  /* The index stream is of the form:
+   * ItemIndex { size_t dataEnd; size_t extraDataEnd; }
+   * It gets concatenated to the end of mOutputStream in Finish()
+   * The last size_t in the stream is offset of the begining of the
+   * index.
+   */
+  MemStream mIndex;
+
+ protected:
+  virtual ~DrawEventRecorderMemory() = default;
+
+ private:
+  SerializeResourcesFn mSerializeCallback;
+  nsTHashSet<uint64_t> mDependentSurfaces;
+
+  void Flush() override;
+};
+
+}  // namespace gfx
+}  // namespace mozilla
+
+#endif /* MOZILLA_GFX_DRAWEVENTRECORDER_H_ */