From ccea287183c5b5aff6f22448fe5f031f5e3e8d02 Mon Sep 17 00:00:00 2001
From: Bas Schouten <bschouten@mozilla.com>
Date: Thu, 16 Jan 2014 13:17:22 +0100
Subject: [PATCH] Bug 960254 - Part 1: Add new Map/Unmap APIs to
 DataSourceSurface. r=jrmuizel

---
 gfx/2d/2D.h | 38 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 36 insertions(+), 2 deletions(-)

diff --git a/gfx/2d/2D.h b/gfx/2d/2D.h
index f084c4e1028..b462817f5b9 100644
--- a/gfx/2d/2D.h
+++ b/gfx/2d/2D.h
@@ -23,6 +23,8 @@
 // solution.
 #include "mozilla/RefPtr.h"
 
+#include "mozilla/DebugOnly.h"
+
 #ifdef MOZ_ENABLE_FREETYPE
 #include <string>
 #endif
@@ -337,14 +339,30 @@ public:
 class DataSourceSurface : public SourceSurface
 {
 public:
+  DataSourceSurface()
+    : mIsMapped(false)
+  {
+  }
+
+  struct MappedSurface {
+    uint8_t *mData;
+    int32_t mStride;
+  };
+
+  enum MapType {
+    READ,
+    WRITE,
+    READ_WRITE
+  };
+
   virtual SurfaceType GetType() const { return SurfaceType::DATA; }
-  /*
+  /* [DEPRECATED]
    * Get the raw bitmap data of the surface.
    * Can return null if there was OOM allocating surface data.
    */
   virtual uint8_t *GetData() = 0;
 
-  /*
+  /* [DEPRECATED]
    * Stride of the surface, distance in bytes between the start of the image
    * data belonging to row y and row y+1. This may be negative.
    * Can return 0 if there was OOM allocating surface data.
@@ -357,11 +375,27 @@ public:
    */
   virtual void MarkDirty() {}
 
+  virtual bool Map(MapType, MappedSurface *aMappedSurface)
+  {
+    aMappedSurface->mData = GetData();
+    aMappedSurface->mStride = Stride();
+    mIsMapped = true;
+    return true;
+  }
+
+  virtual void Unmap()
+  {
+    MOZ_ASSERT(mIsMapped);
+    mIsMapped = false;
+  }
+
   /*
    * Returns a DataSourceSurface with the same data as this one, but
    * guaranteed to have surface->GetType() == SurfaceType::DATA.
    */
   virtual TemporaryRef<DataSourceSurface> GetDataSurface();
+
+  DebugOnly<bool> mIsMapped;
 };
 
 /* This is an abstract object that accepts path segments. */