SkPDFCanon

src/pdf/SkPDFShader.cpp

Index: src/pdf/SkPDFShader.cpp
diff --git a/src/pdf/SkPDFShader.cpp b/src/pdf/SkPDFShader.cpp
index 40f7d93f8907b30ab5c9ae191c449c60fa292879..ec92742b6ea76e253f4e87ea7f1223cc4631aded 100644
--- a/src/pdf/SkPDFShader.cpp
+++ b/src/pdf/SkPDFShader.cpp
@@ -10,6 +10,7 @@
 #include "SkPDFShader.h"
 
 #include "SkData.h"
+#include "SkPDFCanon.h"
 #include "SkPDFCatalog.h"
 #include "SkPDFDevice.h"
 #include "SkPDFFormXObject.h"
@@ -475,7 +476,7 @@ static void drawBitmapMatrix(SkCanvas* canvas, const SkBitmap& bm, const SkMatri
     canvas->drawBitmap(bm, 0, 0);
 }
 
-class SkPDFShader::State {
+class SkPDFShaderState {
 public:
     SkShader::GradientType fType;
     SkShader::GradientInfo fInfo;
@@ -488,35 +489,41 @@ public:
     uint32_t fPixelGeneration;
     SkShader::TileMode fImageTileModes[2];
 
-    State(const SkShader& shader, const SkMatrix& canvasTransform,
-          const SkIRect& bbox);
+    SkPDFShaderState(const SkShader& shader,
+                     const SkMatrix& canvasTransform,
+                     const SkIRect& bbox);
 
-    bool operator==(const State& b) const;
+    bool operator==(const SkPDFShaderState& b) const;
 
-    SkPDFShader::State* CreateAlphaToLuminosityState() const;
-    SkPDFShader::State* CreateOpaqueState() const;
+    SkPDFShaderState* CreateAlphaToLuminosityState() const;
+    SkPDFShaderState* CreateOpaqueState() const;
 
     bool GradientHasAlpha() const;
 
 private:
-    State(const State& other);
-    State operator=(const State& rhs);
+    SkPDFShaderState(const SkPDFShaderState& other);
+    SkPDFShaderState operator=(const SkPDFShaderState& rhs);
     void AllocateGradientInfoStorage();
 };
 
 class SkPDFFunctionShader : public SkPDFDict, public SkPDFShader {
     SK_DECLARE_INST_COUNT(SkPDFFunctionShader)
 public:
-    explicit SkPDFFunctionShader(SkPDFShader::State* state);
+    explicit SkPDFFunctionShader(SkPDFShaderState* state);
     virtual ~SkPDFFunctionShader() {
         if (isValid()) {
-            RemoveShader(this);
+            SkAutoMutexAcquire lock(SkPDFCanon::GetShaderMutex());
+            SkPDFCanon::GetCanon().removeShader(this);
         }
         fResources.unrefAll();
     }
 
     bool isValid() SK_OVERRIDE { return fResources.count() > 0; }
 
+    virtual SkPDFObject* toPDFObject() SK_OVERRIDE {
+        return this;
+    }
+
     void getResources(const SkTSet<SkPDFObject*>& knownResourceObjects,
                       SkTSet<SkPDFObject*>* newResourceObjects) SK_OVERRIDE {
         GetResourcesHelper(&fResources,
@@ -528,7 +535,6 @@ private:
     static SkPDFObject* RangeObject();
 
     SkTDArray<SkPDFObject*> fResources;
-    SkAutoTDelete<const SkPDFShader::State> fState;
 
     SkPDFStream* makePSFunction(const SkString& psCode, SkPDFArray* domain);
     typedef SkPDFDict INHERITED;
@@ -541,10 +547,11 @@ private:
  */
 class SkPDFAlphaFunctionShader : public SkPDFStream, public SkPDFShader {
 public:
-    explicit SkPDFAlphaFunctionShader(SkPDFShader::State* state);
+    explicit SkPDFAlphaFunctionShader(SkPDFShaderState* state);
     virtual ~SkPDFAlphaFunctionShader() {
         if (isValid()) {
-            RemoveShader(this);
+            SkAutoMutexAcquire lock(SkPDFCanon::GetShaderMutex());
+            SkPDFCanon::GetCanon().removeShader(this);
         }
     }
 
@@ -552,9 +559,11 @@ public:
         return fColorShader.get() != NULL;
     }
 
-private:
-    SkAutoTDelete<const SkPDFShader::State> fState;
+    virtual SkPDFObject* toPDFObject() SK_OVERRIDE {
+        return this;
+    }
 
+private:
     SkPDFGraphicState* CreateSMaskGraphicState();
 
     void getResources(const SkTSet<SkPDFObject*>& knownResourceObjects,
@@ -570,16 +579,21 @@ private:
 
 class SkPDFImageShader : public SkPDFStream, public SkPDFShader {
 public:
-    explicit SkPDFImageShader(SkPDFShader::State* state);
+    explicit SkPDFImageShader(SkPDFShaderState* state);
     virtual ~SkPDFImageShader() {
         if (isValid()) {
-            RemoveShader(this);
+            SkAutoMutexAcquire lock(SkPDFCanon::GetShaderMutex());
+            SkPDFCanon::GetCanon().removeShader(this);
         }
         fResources.unrefAll();
     }
 
     bool isValid() SK_OVERRIDE { return size() > 0; }
 
+    virtual SkPDFObject* toPDFObject() SK_OVERRIDE {
+        return this;
+    }
+
     void getResources(const SkTSet<SkPDFObject*>& knownResourceObjects,
                       SkTSet<SkPDFObject*>* newResourceObjects) SK_OVERRIDE {
         GetResourcesHelper(&fResources.toArray(),
@@ -589,16 +603,26 @@ public:
 
 private:
     SkTSet<SkPDFObject*> fResources;
-    SkAutoTDelete<const SkPDFShader::State> fState;
 };
 
-SkPDFShader::SkPDFShader() {}
+SkPDFShader::SkPDFShader(const SkPDFShaderState* state)
+    : fPDFShaderState(state) {
+}
 
-// static
-SkPDFObject* SkPDFShader::GetPDFShaderByState(State* inState) {
-    SkPDFObject* result;
+SkPDFShader::~SkPDFShader() {
+}
+
+bool SkPDFShader::equals(const SkPDFShaderState& state) const {
+    return state == this->pdfShaderState();
+}
+
+const SkPDFShaderState& SkPDFShader::pdfShaderState() const {
+    return *fPDFShaderState;
+}
 
-    SkAutoTDelete<State> shaderState(inState);
+// static
+SkPDFObject* SkPDFShader::GetPDFShaderByState(SkPDFShaderState* inState) {
+    SkAutoTDelete<SkPDFShaderState> shaderState(inState);
     if (shaderState.get()->fType == SkShader::kNone_GradientType &&
             shaderState.get()->fImage.isNull()) {
         // TODO(vandebo) This drops SKComposeShader on the floor.  We could
@@ -608,77 +632,57 @@ SkPDFObject* SkPDFShader::GetPDFShaderByState(State* inState) {
         return NULL;
     }
 
-    ShaderCanonicalEntry entry(NULL, shaderState.get());
-    int index = CanonicalShaders().find(entry);
-    if (index >= 0) {
-        result = CanonicalShaders()[index].fPDFShader;
-        result->ref();
-        return result;
+    SkPDFShader* pdfShader = SkPDFCanon::GetCanon().findShader(*shaderState);
+    if (pdfShader) {
+        return SkRef(pdfShader->toPDFObject());
     }
 
-    bool valid = false;
     // The PDFShader takes ownership of the shaderSate.
-    if (shaderState.get()->fType == SkShader::kNone_GradientType) {
+    if (shaderState->fType == SkShader::kNone_GradientType) {
         SkPDFImageShader* imageShader =
             new SkPDFImageShader(shaderState.detach());
-        valid = imageShader->isValid();
-        result = imageShader;
-    } else {
-        if (shaderState.get()->GradientHasAlpha()) {
-            SkPDFAlphaFunctionShader* gradientShader =
+        if (imageShader->isValid()) {

[mtklein, 2015/01/20 21:59:52]

Might want to extract this if-else block as add_to_canon(SkPDFShader*) ?

[hal.canary, 2015/01/21 17:07:51]

GREAT idea

+            SkPDFCanon::GetCanon().addShader(imageShader);
+            return imageShader->toPDFObject();
+        } else {
+            SkDELETE(imageShader);
+            return NULL;
+        }
+    } else if (shaderState->GradientHasAlpha()) {
+        SkPDFAlphaFunctionShader* gradientShader =
                 SkNEW_ARGS(SkPDFAlphaFunctionShader, (shaderState.detach()));
-            valid = gradientShader->isValid();
-            result = gradientShader;
+        if (gradientShader->isValid()) {
+            SkPDFCanon::GetCanon().addShader(gradientShader);
+            return gradientShader->toPDFObject();
         } else {
-            SkPDFFunctionShader* functionShader =
+            SkDELETE(gradientShader);
+            return NULL;
+        }
+    } else {
+        SkPDFFunctionShader* functionShader =
                 SkNEW_ARGS(SkPDFFunctionShader, (shaderState.detach()));
-            valid = functionShader->isValid();
-            result = functionShader;
+        if (functionShader->isValid()) {
+            SkPDFCanon::GetCanon().addShader(functionShader);
+            return functionShader->toPDFObject();
+        } else {
+            SkDELETE(functionShader);
+            return NULL;
         }
     }
-    if (!valid) {
-        delete result;
-        return NULL;
-    }
-    entry.fPDFShader = result;
-    CanonicalShaders().push(entry);
-    return result;  // return the reference that came from new.
-}
-
-// static
-void SkPDFShader::RemoveShader(SkPDFObject* shader) {
-    SkAutoMutexAcquire lock(CanonicalShadersMutex());
-    ShaderCanonicalEntry entry(shader, NULL);
-    int index = CanonicalShaders().find(entry);
-    SkASSERT(index >= 0);
-    CanonicalShaders().removeShuffle(index);
 }
 
 // static
 SkPDFObject* SkPDFShader::GetPDFShader(const SkShader& shader,
                                        const SkMatrix& matrix,
                                        const SkIRect& surfaceBBox) {
-    SkAutoMutexAcquire lock(CanonicalShadersMutex());
+    SkAutoMutexAcquire lock(SkPDFCanon::GetShaderMutex());
     return GetPDFShaderByState(
-            SkNEW_ARGS(State, (shader, matrix, surfaceBBox)));
-}
-
-// static
-SkTDArray<SkPDFShader::ShaderCanonicalEntry>& SkPDFShader::CanonicalShaders() {
-    SkPDFShader::CanonicalShadersMutex().assertHeld();
-    static SkTDArray<ShaderCanonicalEntry> gCanonicalShaders;
-    return gCanonicalShaders;
-}
-
-SK_DECLARE_STATIC_MUTEX(gCanonicalShadersMutex);
-// static
-SkBaseMutex& SkPDFShader::CanonicalShadersMutex() {
-    return gCanonicalShadersMutex;
+            SkNEW_ARGS(SkPDFShaderState, (shader, matrix, surfaceBBox)));
 }
 
 // static
 SkPDFObject* SkPDFFunctionShader::RangeObject() {
-    SkPDFShader::CanonicalShadersMutex().assertHeld();
+    SkPDFCanon::GetShaderMutex().assertHeld();
     static SkPDFArray* range = NULL;
     // This method is only used with CanonicalShadersMutex, so it's safe to
     // populate domain.
@@ -756,11 +760,10 @@ static SkStream* create_pattern_fill_content(int gsIndex, SkRect& bounds) {
  */
 SkPDFGraphicState* SkPDFAlphaFunctionShader::CreateSMaskGraphicState() {
     SkRect bbox;
-    bbox.set(fState.get()->fBBox);
+    bbox.set(this->pdfShaderState().fBBox);
 
-    SkAutoTUnref<SkPDFObject> luminosityShader(
-            SkPDFShader::GetPDFShaderByState(
-                 fState->CreateAlphaToLuminosityState()));
+    SkAutoTUnref<SkPDFObject> luminosityShader(SkPDFShader::GetPDFShaderByState(
+            this->pdfShaderState().CreateAlphaToLuminosityState()));
 
     SkAutoTUnref<SkStream> alphaStream(create_pattern_fill_content(-1, bbox));
 
@@ -775,10 +778,10 @@ SkPDFGraphicState* SkPDFAlphaFunctionShader::CreateSMaskGraphicState() {
             SkPDFGraphicState::kLuminosity_SMaskMode);
 }
 
-SkPDFAlphaFunctionShader::SkPDFAlphaFunctionShader(SkPDFShader::State* state)
-        : fState(state) {
+SkPDFAlphaFunctionShader::SkPDFAlphaFunctionShader(SkPDFShaderState* state)
+    : SkPDFShader(state) {
     SkRect bbox;
-    bbox.set(fState.get()->fBBox);
+    bbox.set(this->pdfShaderState().fBBox);
 
     fColorShader.reset(
             SkPDFShader::GetPDFShaderByState(state->CreateOpaqueState()));
@@ -835,19 +838,18 @@ static bool split_perspective(const SkMatrix in, SkMatrix* affine,
     return true;
 }
 
-SkPDFFunctionShader::SkPDFFunctionShader(SkPDFShader::State* state)
-        : SkPDFDict("Pattern"),
-          fState(state) {
+SkPDFFunctionShader::SkPDFFunctionShader(SkPDFShaderState* state)
+    : SkPDFDict("Pattern"), SkPDFShader(state) {
     SkString (*codeFunction)(const SkShader::GradientInfo& info,
                              const SkMatrix& perspectiveRemover) = NULL;
     SkPoint transformPoints[2];
 
     // Depending on the type of the gradient, we want to transform the
     // coordinate space in different ways.
-    const SkShader::GradientInfo* info = &fState.get()->fInfo;
+    const SkShader::GradientInfo* info = &this->pdfShaderState().fInfo;

[mtklein, 2015/01/20 21:59:52]

Why don't we just write "this->pdfShaderState()" as "fState"?

[hal.canary, 2015/01/21 17:07:51]

Done.

     transformPoints[0] = info->fPoint[0];
     transformPoints[1] = info->fPoint[1];
-    switch (fState.get()->fType) {
+    switch (this->pdfShaderState().fType) {
         case SkShader::kLinear_GradientType:
             codeFunction = &linearCode;
             break;
@@ -892,8 +894,8 @@ SkPDFFunctionShader::SkPDFFunctionShader(SkPDFShader::State* state)
     SkMatrix mapperMatrix;
     unitToPointsMatrix(transformPoints, &mapperMatrix);
 
-    SkMatrix finalMatrix = fState.get()->fCanvasTransform;
-    finalMatrix.preConcat(fState.get()->fShaderTransform);
+    SkMatrix finalMatrix = this->pdfShaderState().fCanvasTransform;
+    finalMatrix.preConcat(this->pdfShaderState().fShaderTransform);
     finalMatrix.preConcat(mapperMatrix);
 
     // Preserves as much as posible in the final matrix, and only removes
@@ -910,7 +912,7 @@ SkPDFFunctionShader::SkPDFFunctionShader(SkPDFShader::State* state)
     }
 
     SkRect bbox;
-    bbox.set(fState.get()->fBBox);
+    bbox.set(this->pdfShaderState().fBBox);
     if (!inverseTransformBBox(finalMatrix, &bbox)) {
         return;
     }
@@ -923,10 +925,11 @@ SkPDFFunctionShader::SkPDFFunctionShader(SkPDFShader::State* state)
     domain->appendScalar(bbox.fBottom);
 
     SkString functionCode;
-    // The two point radial gradient further references fState.get()->fInfo
+    // The two point radial gradient further references
+    // this->pdfShaderState().fInfo
     // in translating from x, y coordinates to the t parameter. So, we have
     // to transform the points and radii according to the calculated matrix.
-    if (fState.get()->fType == SkShader::kRadial2_GradientType) {
+    if (this->pdfShaderState().fType == SkShader::kRadial2_GradientType) {
         SkShader::GradientInfo twoPointRadialInfo = *info;
         SkMatrix inverseMapperMatrix;
         if (!mapperMatrix.invert(&inverseMapperMatrix)) {
@@ -956,8 +959,9 @@ SkPDFFunctionShader::SkPDFFunctionShader(SkPDFShader::State* state)
     insert("Shading", pdfShader.get());
 }
 
-SkPDFImageShader::SkPDFImageShader(SkPDFShader::State* state) : fState(state) {
-    fState.get()->fImage.lockPixels();
+SkPDFImageShader::SkPDFImageShader(SkPDFShaderState* state)
+    : SkPDFShader(state) {
+    this->pdfShaderState().fImage.lockPixels();
 
     // The image shader pattern cell will be drawn into a separate device
     // in pattern cell space (no scaling on the bitmap, though there may be
@@ -965,15 +969,15 @@ SkPDFImageShader::SkPDFImageShader(SkPDFShader::State* state) : fState(state) {
 
     // Map clip bounds to shader space to ensure the device is large enough
     // to handle fake clamping.
-    SkMatrix finalMatrix = fState.get()->fCanvasTransform;
-    finalMatrix.preConcat(fState.get()->fShaderTransform);
+    SkMatrix finalMatrix = this->pdfShaderState().fCanvasTransform;
+    finalMatrix.preConcat(this->pdfShaderState().fShaderTransform);
     SkRect deviceBounds;
-    deviceBounds.set(fState.get()->fBBox);
+    deviceBounds.set(this->pdfShaderState().fBBox);
     if (!inverseTransformBBox(finalMatrix, &deviceBounds)) {
         return;
     }
 
-    const SkBitmap* image = &fState.get()->fImage;
+    const SkBitmap* image = &this->pdfShaderState().fImage;
     SkRect bitmapBounds;
     image->getBounds(&bitmapBounds);
 
@@ -982,8 +986,8 @@ SkPDFImageShader::SkPDFImageShader(SkPDFShader::State* state) : fState(state) {
     // For clamp modes, we're only interested in the clip region, whether
     // or not the main bitmap is in it.
     SkShader::TileMode tileModes[2];
-    tileModes[0] = fState.get()->fImageTileModes[0];
-    tileModes[1] = fState.get()->fImageTileModes[1];
+    tileModes[0] = this->pdfShaderState().fImageTileModes[0];
+    tileModes[1] = this->pdfShaderState().fImageTileModes[1];
     if (tileModes[0] != SkShader::kClamp_TileMode ||
             tileModes[1] != SkShader::kClamp_TileMode) {
         deviceBounds.join(bitmapBounds);
@@ -1163,7 +1167,7 @@ SkPDFImageShader::SkPDFImageShader(SkPDFShader::State* state) : fState(state) {
     populate_tiling_pattern_dict(this, patternBBox,
                                  pattern.getResourceDict(), finalMatrix);
 
-    fState.get()->fImage.unlockPixels();
+    this->pdfShaderState().fImage.unlockPixels();
 }
 
 SkPDFStream* SkPDFFunctionShader::makePSFunction(const SkString& psCode, SkPDFArray* domain) {
@@ -1175,17 +1179,7 @@ SkPDFStream* SkPDFFunctionShader::makePSFunction(const SkString& psCode, SkPDFAr
     return result;
 }
 
-SkPDFShader::ShaderCanonicalEntry::ShaderCanonicalEntry(SkPDFObject* pdfShader, const State* state)
-    : fPDFShader(pdfShader)
-    , fState(state)
-{}
-
-bool SkPDFShader::ShaderCanonicalEntry::operator==(const ShaderCanonicalEntry& b) const {
-    return fPDFShader == b.fPDFShader ||
-           (fState != NULL && b.fState != NULL && *fState == *b.fState);
-}
-
-bool SkPDFShader::State::operator==(const SkPDFShader::State& b) const {
+bool SkPDFShaderState::operator==(const SkPDFShaderState& b) const {
     if (fType != b.fType ||
             fCanvasTransform != b.fCanvasTransform ||
             fShaderTransform != b.fShaderTransform ||
@@ -1239,11 +1233,10 @@ bool SkPDFShader::State::operator==(const SkPDFShader::State& b) const {
     return true;
 }
 
-SkPDFShader::State::State(const SkShader& shader,
-                          const SkMatrix& canvasTransform, const SkIRect& bbox)
-        : fCanvasTransform(canvasTransform),
-          fBBox(bbox),
-          fPixelGeneration(0) {
+SkPDFShaderState::SkPDFShaderState(const SkShader& shader,
+                                   const SkMatrix& canvasTransform,
+                                   const SkIRect& bbox)
+    : fCanvasTransform(canvasTransform), fBBox(bbox), fPixelGeneration(0) {
     fInfo.fColorCount = 0;
     fInfo.fColors = NULL;
     fInfo.fColorOffsets = NULL;
@@ -1268,12 +1261,11 @@ SkPDFShader::State::State(const SkShader& shader,
     }
 }
 
-SkPDFShader::State::State(const SkPDFShader::State& other)
-  : fType(other.fType),
-    fCanvasTransform(other.fCanvasTransform),
-    fShaderTransform(other.fShaderTransform),
-    fBBox(other.fBBox)
-{
+SkPDFShaderState::SkPDFShaderState(const SkPDFShaderState& other)
+    : fType(other.fType)
+    , fCanvasTransform(other.fCanvasTransform)
+    , fShaderTransform(other.fShaderTransform)
+    , fBBox(other.fBBox) {
     // Only gradients supported for now, since that is all that is used.
     // If needed, image state copy constructor can be added here later.
     SkASSERT(fType != SkShader::kNone_GradientType);
@@ -1293,10 +1285,10 @@ SkPDFShader::State::State(const SkPDFShader::State& other)
  * Create a copy of this gradient state with alpha assigned to RGB luminousity.
  * Only valid for gradient states.
  */
-SkPDFShader::State* SkPDFShader::State::CreateAlphaToLuminosityState() const {
+SkPDFShaderState* SkPDFShaderState::CreateAlphaToLuminosityState() const {
     SkASSERT(fType != SkShader::kNone_GradientType);
 
-    SkPDFShader::State* newState = new SkPDFShader::State(*this);
+    SkPDFShaderState* newState = new SkPDFShaderState(*this);
 
     for (int i = 0; i < fInfo.fColorCount; i++) {
         SkAlpha alpha = SkColorGetA(fInfo.fColors[i]);
@@ -1310,10 +1302,10 @@ SkPDFShader::State* SkPDFShader::State::CreateAlphaToLuminosityState() const {
  * Create a copy of this gradient state with alpha set to fully opaque
  * Only valid for gradient states.
  */
-SkPDFShader::State* SkPDFShader::State::CreateOpaqueState() const {
+SkPDFShaderState* SkPDFShaderState::CreateOpaqueState() const {
     SkASSERT(fType != SkShader::kNone_GradientType);
 
-    SkPDFShader::State* newState = new SkPDFShader::State(*this);
+    SkPDFShaderState* newState = new SkPDFShaderState(*this);
     for (int i = 0; i < fInfo.fColorCount; i++) {
         newState->fInfo.fColors[i] = SkColorSetA(fInfo.fColors[i],
                                                  SK_AlphaOPAQUE);
@@ -1325,7 +1317,7 @@ SkPDFShader::State* SkPDFShader::State::CreateOpaqueState() const {
 /**
  * Returns true if state is a gradient and the gradient has alpha.
  */
-bool SkPDFShader::State::GradientHasAlpha() const {
+bool SkPDFShaderState::GradientHasAlpha() const {
     if (fType == SkShader::kNone_GradientType) {
         return false;
     }
@@ -1339,7 +1331,7 @@ bool SkPDFShader::State::GradientHasAlpha() const {
     return false;
 }
 
-void SkPDFShader::State::AllocateGradientInfoStorage() {
+void SkPDFShaderState::AllocateGradientInfoStorage() {
     fColorData.set(sk_malloc_throw(
                fInfo.fColorCount * (sizeof(SkColor) + sizeof(SkScalar))));
     fInfo.fColors = reinterpret_cast<SkColor*>(fColorData.get());