1 files changed, 142 insertions, 0 deletions
diff --git a/gfx/2d/CaptureCommandList.h b/gfx/2d/CaptureCommandList.h
new file mode 100644
index 0000000000..f47aacb263
--- /dev/null
+++ b/gfx/2d/CaptureCommandList.h
@@ -0,0 +1,142 @@
+/* -*- 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_2d_CaptureCommandList_h
+#define mozilla_gfx_2d_CaptureCommandList_h
+
+#include <limits>
+#include <utility>
+#include <vector>
+
+#include "DrawCommand.h"
+#include "Logging.h"
+#include "mozilla/PodOperations.h"
+
+// Command object is stored into record with header containing size and
+// redundant size of whole record. Some platforms may require Command
+// object to be stored on 8 bytes aligned address. Therefore we need to
+// adjust size of header for these platforms.
+#ifdef __sparc__
+typedef uint32_t kAdvance_t;
+#else
+typedef uint16_t kAdvance_t;
+#endif
+
+namespace mozilla {
+namespace gfx {
+
+class CaptureCommandList {
+ public:
+  CaptureCommandList() : mLastCommand(nullptr) {}
+  CaptureCommandList(CaptureCommandList&& aOther)
+      : mStorage(std::move(aOther.mStorage)),
+        mLastCommand(aOther.mLastCommand) {
+    aOther.mLastCommand = nullptr;
+  }
+  ~CaptureCommandList();
+
+  CaptureCommandList& operator=(CaptureCommandList&& aOther) {
+    mStorage = std::move(aOther.mStorage);
+    mLastCommand = aOther.mLastCommand;
+    aOther.mLastCommand = nullptr;
+    return *this;
+  }
+
+  template <typename T>
+  T* Append() {
+    static_assert(sizeof(T) + 2 * sizeof(kAdvance_t) <=
+                      std::numeric_limits<kAdvance_t>::max(),
+                  "encoding is too small to contain advance");
+    const kAdvance_t kAdvance = sizeof(T) + 2 * sizeof(kAdvance_t);
+
+    size_t size = mStorage.size();
+    mStorage.resize(size + kAdvance);
+
+    uint8_t* current = &mStorage.front() + size;
+    *(kAdvance_t*)(current) = kAdvance;
+    current += sizeof(kAdvance_t);
+    *(kAdvance_t*)(current) = ~kAdvance;
+    current += sizeof(kAdvance_t);
+
+    T* command = reinterpret_cast<T*>(current);
+    mLastCommand = command;
+    return command;
+  }
+
+  template <typename T>
+  T* ReuseOrAppend() {
+    {  // Scope lock
+      if (mLastCommand != nullptr && mLastCommand->GetType() == T::Type) {
+        return reinterpret_cast<T*>(mLastCommand);
+      }
+    }
+    return Append<T>();
+  }
+
+  bool IsEmpty() const { return mStorage.empty(); }
+
+  template <typename T>
+  bool BufferWillAlloc() const {
+    const kAdvance_t kAdvance = sizeof(T) + 2 * sizeof(kAdvance_t);
+    return mStorage.size() + kAdvance > mStorage.capacity();
+  }
+
+  size_t BufferCapacity() const { return mStorage.capacity(); }
+
+  void Clear();
+
+  class iterator {
+   public:
+    explicit iterator(CaptureCommandList& aParent)
+        : mParent(aParent), mCurrent(nullptr), mEnd(nullptr) {
+      if (!mParent.mStorage.empty()) {
+        mCurrent = &mParent.mStorage.front();
+        mEnd = mCurrent + mParent.mStorage.size();
+      }
+    }
+
+    bool Done() const { return mCurrent >= mEnd; }
+    void Next() {
+      MOZ_ASSERT(!Done());
+      kAdvance_t advance = *reinterpret_cast<kAdvance_t*>(mCurrent);
+      kAdvance_t redundant =
+          ~*reinterpret_cast<kAdvance_t*>(mCurrent + sizeof(kAdvance_t));
+      MOZ_RELEASE_ASSERT(advance == redundant);
+      mCurrent += advance;
+    }
+    DrawingCommand* Get() {
+      MOZ_ASSERT(!Done());
+      return reinterpret_cast<DrawingCommand*>(mCurrent +
+                                               2 * sizeof(kAdvance_t));
+    }
+
+   private:
+    CaptureCommandList& mParent;
+    uint8_t* mCurrent;
+    uint8_t* mEnd;
+  };
+
+  void Log(TreeLog<>& aStream) {
+    for (iterator iter(*this); !iter.Done(); iter.Next()) {
+      DrawingCommand* cmd = iter.Get();
+      cmd->Log(aStream);
+      aStream << "\n";
+    }
+  }
+
+ private:
+  CaptureCommandList(const CaptureCommandList& aOther) = delete;
+  void operator=(const CaptureCommandList& aOther) = delete;
+
+ private:
+  std::vector<uint8_t> mStorage;
+  DrawingCommand* mLastCommand;
+};
+
+}  // namespace gfx
+}  // namespace mozilla
+
+#endif  // mozilla_gfx_2d_CaptureCommandList_h