unify pixelref and image ID space, so we can share IDs when we share pixels

I view this as a performance opportunity, not a feature or bug fix per-se.

BUG=skia:

Review URL: https://codereview.chromium.org/1266883002

6 files changed, 31 insertions, 26 deletions

diff --git a/src/image/SkImage.cpp b/src/image/SkImage.cpp
index 081785f4b3..a17f336c9c 100644
--- a/src/image/SkImage.cpp
+++ b/src/image/SkImage.cpp
@@ -11,6 +11,7 @@
 #include "SkImageGenerator.h"
 #include "SkImagePriv.h"
 #include "SkImage_Base.h"
+#include "SkNextID.h"
 #include "SkPixelRef.h"
 #include "SkReadPixelsRec.h"
 #include "SkString.h"
@@ -22,15 +23,13 @@
 #include "SkImage_Gpu.h"
 #endif
 
-uint32_t SkImage::NextUniqueID() {
-    static int32_t gUniqueID;
-
-    // never return 0;
-    uint32_t id;
-    do {
-        id = sk_atomic_inc(&gUniqueID) + 1;
-    } while (0 == id);
-    return id;
+SkImage::SkImage(int width, int height, uint32_t uniqueID)
+    : fWidth(width)
+    , fHeight(height)
+    , fUniqueID(kNeedNewImageUniqueID == uniqueID ? SkNextID::ImageID() : uniqueID)
+{
+    SkASSERT(width > 0);
+    SkASSERT(height > 0);
 }
 
 const void* SkImage::peekPixels(SkImageInfo* info, size_t* rowBytes) const {
@@ -248,8 +247,8 @@ SkImage* SkImage::NewFromBitmap(const SkBitmap& bm) {
             unrefCopy.reset(tex);
         }
         const SkImageInfo info = bm.info();
-        return SkNEW_ARGS(SkImage_Gpu, (info.width(), info.height(), info.alphaType(),
-                                        tex, 0, SkSurface::kNo_Budgeted));
+        return SkNEW_ARGS(SkImage_Gpu, (info.width(), info.height(), bm.getGenerationID(),
+                                        info.alphaType(), tex, 0, SkSurface::kNo_Budgeted));
     }
 #endif
 
diff --git a/src/image/SkImage_Base.h b/src/image/SkImage_Base.h
index b3661d99fe..37dcb40d25 100644
--- a/src/image/SkImage_Base.h
+++ b/src/image/SkImage_Base.h
@@ -11,14 +11,18 @@
 #include "SkImage.h"
 #include "SkSurface.h"
 
+enum {
+    kNeedNewImageUniqueID = 0
+};
+
 static SkSurfaceProps copy_or_safe_defaults(const SkSurfaceProps* props) {
     return props ? *props : SkSurfaceProps(0, kUnknown_SkPixelGeometry);
 }
 
 class SkImage_Base : public SkImage {
 public:
-    SkImage_Base(int width, int height, const SkSurfaceProps* props)
-        : INHERITED(width, height)
+    SkImage_Base(int width, int height, uint32_t uniqueID, const SkSurfaceProps* props)
+        : INHERITED(width, height, uniqueID)
         , fProps(copy_or_safe_defaults(props))
     {}
 
diff --git a/src/image/SkImage_Gpu.cpp b/src/image/SkImage_Gpu.cpp
index 31ae5a90fd..7ce6831b63 100644
--- a/src/image/SkImage_Gpu.cpp
+++ b/src/image/SkImage_Gpu.cpp
@@ -13,9 +13,9 @@
 #include "SkGpuDevice.h"
 
 
-SkImage_Gpu::SkImage_Gpu(int w, int h, SkAlphaType at, GrTexture* tex,
+SkImage_Gpu::SkImage_Gpu(int w, int h, uint32_t uniqueID, SkAlphaType at, GrTexture* tex,
                          int sampleCountForNewSurfaces, SkSurface::Budgeted budgeted)
-    : INHERITED(w, h, NULL)
+    : INHERITED(w, h, uniqueID, NULL)
     , fTexture(SkRef(tex))
     , fSampleCountForNewSurfaces(sampleCountForNewSurfaces)
     , fAlphaType(at)
@@ -130,7 +130,8 @@ static SkImage* new_wrapped_texture_common(GrContext* ctx, const GrBackendTextur
     }
 
     const SkSurface::Budgeted budgeted = SkSurface::kNo_Budgeted;
-    return SkNEW_ARGS(SkImage_Gpu, (desc.fWidth, desc.fHeight, at, tex, 0, budgeted));
+    return SkNEW_ARGS(SkImage_Gpu,
+                      (desc.fWidth, desc.fHeight, kNeedNewImageUniqueID, at, tex, 0, budgeted));
 
 }
 
@@ -164,7 +165,8 @@ SkImage* SkImage::NewFromTextureCopy(GrContext* ctx, const GrBackendTextureDesc&
 
     const SkSurface::Budgeted budgeted = SkSurface::kYes_Budgeted;
     const int sampleCount = 0;  // todo: make this an explicit parameter to newSurface()?
-    return SkNEW_ARGS(SkImage_Gpu, (desc.fWidth, desc.fHeight, at, dst, sampleCount, budgeted));
+    return SkNEW_ARGS(SkImage_Gpu, (desc.fWidth, desc.fHeight, kNeedNewImageUniqueID,
+                                    at, dst, sampleCount, budgeted));
 }
 
 SkImage* SkImage::NewFromYUVTexturesCopy(GrContext* ctx , SkYUVColorSpace colorSpace,
@@ -238,8 +240,8 @@ SkImage* SkImage::NewFromYUVTexturesCopy(GrContext* ctx , SkYUVColorSpace colorS
     GrDrawContext* drawContext = ctx->drawContext();
     drawContext->drawRect(dst->asRenderTarget(), GrClip::WideOpen(), paint, SkMatrix::I(), rect);
     ctx->flushSurfaceWrites(dst);
-    return SkNEW_ARGS(SkImage_Gpu, (dstDesc.fWidth, dstDesc.fHeight, kOpaque_SkAlphaType, dst, 0,
-                                    budgeted));
+    return SkNEW_ARGS(SkImage_Gpu, (dstDesc.fWidth, dstDesc.fHeight, kNeedNewImageUniqueID,
+                                    kOpaque_SkAlphaType, dst, 0, budgeted));
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
diff --git a/src/image/SkImage_Gpu.h b/src/image/SkImage_Gpu.h
index df26f82b74..4c7ebd6f71 100644
--- a/src/image/SkImage_Gpu.h
+++ b/src/image/SkImage_Gpu.h
@@ -23,8 +23,8 @@ public:
      *  An "image" can be a subset/window into a larger texture, so we explicit take the
      *  width and height.
      */
-    SkImage_Gpu(int w, int h, SkAlphaType, GrTexture*, int sampleCountForNewSurfaces,
-                SkSurface::Budgeted);
+    SkImage_Gpu(int w, int h, uint32_t uniqueID, SkAlphaType, GrTexture*,
+                int sampleCountForNewSurfaces, SkSurface::Budgeted);
 
     void applyBudgetDecision() const {
         GrTexture* tex = this->getTexture();
diff --git a/src/image/SkImage_Raster.cpp b/src/image/SkImage_Raster.cpp
index bde4c347aa..7b5cf9bb1b 100644
--- a/src/image/SkImage_Raster.cpp
+++ b/src/image/SkImage_Raster.cpp
@@ -82,7 +82,7 @@ public:
     bool onAsLegacyBitmap(SkBitmap*, LegacyBitmapMode) const override;
 
     SkImage_Raster(const SkBitmap& bm, const SkSurfaceProps* props, bool lockPixels = false)
-        : INHERITED(bm.width(), bm.height(), props)
+        : INHERITED(bm.width(), bm.height(), bm.getGenerationID(), props)
         , fBitmap(bm) {
         if (lockPixels) {
             fBitmap.lockPixels();
@@ -91,7 +91,7 @@ public:
     }
 
 private:
-    SkImage_Raster() : INHERITED(0, 0, NULL) {
+    SkImage_Raster() : INHERITED(0, 0, fBitmap.getGenerationID(), NULL) {
         fBitmap.setImmutable();
     }
 
@@ -109,7 +109,7 @@ static void release_data(void* addr, void* context) {
 
 SkImage_Raster::SkImage_Raster(const Info& info, SkData* data, size_t rowBytes,
                                SkColorTable* ctable, const SkSurfaceProps* props)
-    : INHERITED(info.width(), info.height(), props)
+    : INHERITED(info.width(), info.height(), kNeedNewImageUniqueID, props)
 {
     data->ref();
     void* addr = const_cast<void*>(data->data());
@@ -121,7 +121,7 @@ SkImage_Raster::SkImage_Raster(const Info& info, SkData* data, size_t rowBytes,
 
 SkImage_Raster::SkImage_Raster(const Info& info, SkPixelRef* pr, const SkIPoint& pixelRefOrigin,
                                size_t rowBytes,  const SkSurfaceProps* props)
-    : INHERITED(info.width(), info.height(), props)
+    : INHERITED(info.width(), info.height(), pr->getGenerationID(), props)
 {
     fBitmap.setInfo(info, rowBytes);
     fBitmap.setPixelRef(pr, pixelRefOrigin);
diff --git a/src/image/SkSurface_Gpu.cpp b/src/image/SkSurface_Gpu.cpp
index 67f54d5bbb..dbe82f8c9f 100644
--- a/src/image/SkSurface_Gpu.cpp
+++ b/src/image/SkSurface_Gpu.cpp
@@ -83,7 +83,7 @@ SkImage* SkSurface_Gpu::onNewImageSnapshot(Budgeted budgeted) {
     GrTexture* tex = fDevice->accessRenderTarget()->asTexture();
     if (tex) {
         image = SkNEW_ARGS(SkImage_Gpu,
-                           (info.width(), info.height(), info.alphaType(),
+                           (info.width(), info.height(), kNeedNewImageUniqueID, info.alphaType(),
                             tex, sampleCount, budgeted));
     }
     if (image) {