SkPDF: SkPDFGraphicState Lookup hashtabled

src/pdf/SkPDFCanon.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkPDFCanon_DEFINED
 #define SkPDFCanon_DEFINED
 
+#include "SkPDFGraphicState.h"
 #include "SkPDFShader.h"
 #include "SkTDArray.h"
+#include "SkTHash.h"
 
 class SkBitmap;
 class SkPDFFont;
-class SkPDFGraphicState;
 class SkPDFBitmap;
 class SkPaint;
 
 /**
  *  The SkPDFCanon canonicalizes objects across PDF pages(SkPDFDevices).
  *
  *  The PDF backend works correctly if:
  *  -  There is no more than one SkPDFCanon for each thread.
  *  -  Every SkPDFDevice is given a pointer to a SkPDFCanon on creation.
  *  -  All SkPDFDevices in a document share the same SkPDFCanon.
@@ skipping 23 matching lines @@
 
     SkPDFFunctionShader* findFunctionShader(const SkPDFShader::State&) const;
     void addFunctionShader(SkPDFFunctionShader*);
 
     SkPDFAlphaFunctionShader* findAlphaShader(const SkPDFShader::State&) const;
     void addAlphaShader(SkPDFAlphaFunctionShader*);
 
     SkPDFImageShader* findImageShader(const SkPDFShader::State&) const;
     void addImageShader(SkPDFImageShader*);
 
-    SkPDFGraphicState* findGraphicState(const SkPaint&) const;
-    void addGraphicState(SkPDFGraphicState*);
+    const SkPDFGraphicState* findGraphicState(const SkPDFGraphicState&) const;
+    void addGraphicState(const SkPDFGraphicState*);
 
     SkPDFBitmap* findBitmap(const SkBitmap&) const;
     void addBitmap(SkPDFBitmap*);
 
 private:
     struct FontRec {
         SkPDFFont* fFont;
         uint32_t fFontID;
         uint16_t fGlyphID;
     };
     SkTDArray<FontRec> fFontRecords;
 
     SkTDArray<SkPDFFunctionShader*> fFunctionShaderRecords;
 
     SkTDArray<SkPDFAlphaFunctionShader*> fAlphaShaderRecords;
 
     SkTDArray<SkPDFImageShader*> fImageShaderRecords;
 
-    SkTDArray<SkPDFGraphicState*> fGraphicStateRecords;
+    struct WrapGS {
+        explicit WrapGS(const SkPDFGraphicState* ptr = NULL) : fPtr(ptr) {}
+        const SkPDFGraphicState* fPtr;
+        bool operator==(const WrapGS& rhs) const {
+            SkASSERT(fPtr);
+            SkASSERT(rhs.fPtr);
+            return *fPtr == *rhs.fPtr;
+        }
+        static uint32_t Hash(const WrapGS& w) {
+            SkASSERT(w.fPtr);
+            return w.fPtr->hash();
+        }
+    };
+    SkTHashSet<WrapGS, WrapGS::Hash> fGraphicStateRecords;
 
     SkTDArray<SkPDFBitmap*> fBitmapRecords;
 };
 #endif  // SkPDFCanon_DEFINED