SkRemote: more refactoring

src/core/SkRemote.cpp

Index: src/core/SkRemote.cpp
diff --git a/src/core/SkRemote.cpp b/src/core/SkRemote.cpp
index 21fbdf3d978a078077f2bcba953545f11874d5c7..ff658ff20d146f92158d0b6eb00678bbc31124f7 100644
--- a/src/core/SkRemote.cpp
+++ b/src/core/SkRemote.cpp
@@ -5,9 +5,12 @@
  * found in the LICENSE file.
  */
 
+#include "SkCanvas.h"
 #include "SkPath.h"
 #include "SkRect.h"
 #include "SkRemote.h"
+#include "SkShader.h"
+#include "SkTHash.h"
 
 namespace SkRemote {
 
@@ -72,6 +75,278 @@ namespace SkRemote {
 
     // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ //
 
+    class Canvas final : public SkCanvas {
+    public:
+        explicit Canvas(Encoder* encoder)
+            : SkCanvas(1,1)
+            , fEncoder(encoder) {}
+
+    private:
+        // Calls Encoder::define() when created, Encoder::undefine() when destroyed.
+        class AutoID : ::SkNoncopyable {
+        public:
+            template <typename T>
+            explicit AutoID(Encoder* encoder, const T& val)
+                : fEncoder(encoder)
+                , fID(encoder->define(val)) {}
+            ~AutoID() { if (fEncoder) fEncoder->undefine(fID); }
+
+            AutoID(AutoID&& o) : fEncoder(o.fEncoder), fID(o.fID) {
+                o.fEncoder = nullptr;
+            }
+            AutoID& operator=(AutoID&&) = delete;
+
+            operator ID () const { return fID; }
+
+        private:
+            Encoder* fEncoder;
+            const ID fID;
+        };
+
+        template <typename T>
+        AutoID id(const T& val) { return AutoID(fEncoder, val); }
+
+        void   willSave() override { fEncoder->   save(); }
+        void didRestore() override { fEncoder->restore(); }
+
+        void    didConcat(const SkMatrix&) override { this->didSetMatrix(this->getTotalMatrix()); }
+        void didSetMatrix(const SkMatrix& matrix) override {
+            fEncoder->setMatrix(this->id(matrix));
+        }
+
+        void onDrawOval(const SkRect& oval, const SkPaint& paint) override {
+            SkPath path;
+            path.addOval(oval);
+            this->onDrawPath(path, paint);
+        }
+
+        void onDrawRect(const SkRect& rect, const SkPaint& paint) override {
+            SkPath path;
+            path.addRect(rect);
+            this->onDrawPath(path, paint);
+        }
+
+        void onDrawRRect(const SkRRect& rrect, const SkPaint& paint) override {
+            SkPath path;
+            path.addRRect(rrect);
+            this->onDrawPath(path, paint);
+        }
+
+        void onDrawDRRect(const SkRRect& outside, const SkRRect& inside,
+                          const SkPaint& paint) override {
+            SkPath path;
+            path.addRRect(outside);
+            path.addRRect(inside, SkPath::kCCW_Direction);
+            this->onDrawPath(path, paint);
+        }
+
+        void onDrawPath(const SkPath& path, const SkPaint& paint) override {
+            auto p = this->id(path),
+                 m = this->id(Misc::CreateFrom(paint)),
+                 s = this->id(paint.getShader()),
+                 x = this->id(paint.getXfermode());
+
+            if (paint.getStyle() == SkPaint::kFill_Style) {
+                fEncoder->fillPath(p, m, s, x);
+            } else {
+                // TODO: handle kStrokeAndFill_Style
+                fEncoder->strokePath(p, m, s, x, this->id(Stroke::CreateFrom(paint)));
+            }
+        }
+
+        void onDrawPaint(const SkPaint& paint) override {
+            SkPath path;
+            path.setFillType(SkPath::kInverseWinding_FillType);  // Either inverse FillType is fine.
+            this->onDrawPath(path, paint);
+        }
+
+        void onDrawText(const void* text, size_t byteLength,
+                        SkScalar x, SkScalar y, const SkPaint& paint) override {
+            // Text-as-paths is a temporary hack.
+            // TODO: send SkTextBlobs and SkTypefaces
+            SkPath path;
+            paint.getTextPath(text, byteLength, x, y, &path);
+            this->onDrawPath(path, paint);
+        }
+
+        void onDrawPosText(const void* text, size_t byteLength,
+                           const SkPoint pos[], const SkPaint& paint) override {
+            // Text-as-paths is a temporary hack.
+            // TODO: send SkTextBlobs and SkTypefaces
+            SkPath path;
+            paint.getPosTextPath(text, byteLength, pos, &path);
+            this->onDrawPath(path, paint);
+        }
+
+        void onDrawPosTextH(const void* text, size_t byteLength,
+                            const SkScalar xpos[], SkScalar constY, const SkPaint& paint) override {
+            size_t length = paint.countText(text, byteLength);
+            SkAutoTArray<SkPoint> pos(length);
+            for(size_t i = 0; i < length; ++i) {
+                pos[i].set(xpos[i], constY);
+            }
+            this->onDrawPosText(text, byteLength, &pos[0], paint);
+        }
+
+        void onClipRect(const SkRect& rect, SkRegion::Op op, ClipEdgeStyle edgeStyle) override {
+            SkPath path;
+            path.addRect(rect);
+            this->onClipPath(path, op, edgeStyle);
+        }
+
+        void onClipRRect(const SkRRect& rrect, SkRegion::Op op, ClipEdgeStyle edgeStyle) override {
+            SkPath path;
+            path.addRRect(rrect);
+            this->onClipPath(path, op, edgeStyle);
+        }
+
+        void onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle edgeStyle) override {
+            fEncoder->clipPath(this->id(path), op, edgeStyle == kSoft_ClipEdgeStyle);
+        }
+
+        Encoder* fEncoder;
+    };
+
+    SkCanvas* NewCanvas(Encoder* encoder) { return new Canvas(encoder); }
+
+    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ //
+
+    class Decoder final : public Encoder {
+    public:
+        explicit Decoder(SkCanvas* canvas) : fCanvas(canvas) {}
+
+    private:
+        template <typename Map, typename T>
+        ID define(Type type, Map* map, const T& val) {
+            ID id(type, fNextID++);
+            map->set(id, val);
+            return id;
+        }
+
+        ID define(const SkMatrix& v) override {return this->define(Type::kMatrix,   &fMatrix,   v);}
+        ID define(const Misc&     v) override {return this->define(Type::kMisc,     &fMisc,     v);}
+        ID define(const SkPath&   v) override {return this->define(Type::kPath,     &fPath,     v);}
+        ID define(const Stroke&   v) override {return this->define(Type::kStroke,   &fStroke,   v);}
+        ID define(SkShader*       v) override {return this->define(Type::kShader,   &fShader,   v);}
+        ID define(SkXfermode*     v) override {return this->define(Type::kXfermode, &fXfermode, v);}
+
+        void undefine(ID id) override {
+            switch(id.type()) {
+                case Type::kMatrix:   return fMatrix  .remove(id);
+                case Type::kMisc:     return fMisc    .remove(id);
+                case Type::kPath:     return fPath    .remove(id);
+                case Type::kStroke:   return fStroke  .remove(id);
+                case Type::kShader:   return fShader  .remove(id);
+                case Type::kXfermode: return fXfermode.remove(id);
+            };
+        }
+
+        void    save() override { fCanvas->save(); }
+        void restore() override { fCanvas->restore(); }
+
+        void setMatrix(ID matrix) override { fCanvas->setMatrix(fMatrix.find(matrix)); }
+
+        void clipPath(ID path, SkRegion::Op op, bool aa) override {
+            fCanvas->clipPath(fPath.find(path), op, aa);
+        }
+        void fillPath(ID path, ID misc, ID shader, ID xfermode) override {
+            SkPaint paint;
+            paint.setStyle(SkPaint::kFill_Style);
+            fMisc.find(misc).applyTo(&paint);
+            paint.setShader  (fShader  .find(shader));
+            paint.setXfermode(fXfermode.find(xfermode));
+            fCanvas->drawPath(fPath.find(path), paint);
+        }
+        void strokePath(ID path, ID misc, ID shader, ID xfermode, ID stroke) override {
+            SkPaint paint;
+            paint.setStyle(SkPaint::kStroke_Style);
+            fMisc  .find(misc  ).applyTo(&paint);
+            fStroke.find(stroke).applyTo(&paint);
+            paint.setShader  (fShader  .find(shader));
+            paint.setXfermode(fXfermode.find(xfermode));
+            fCanvas->drawPath(fPath.find(path), paint);
+        }
+
+        // Maps ID -> T.
+        template <typename T, Type kType>
+        class IDMap {
+        public:
+            ~IDMap() {
+                // A well-behaved client always cleans up its definitions.
+                SkASSERT(fMap.count() == 0);
+            }
+
+            void set(const ID& id, const T& val) {
+                SkASSERT(id.type() == kType);
+                fMap.set(id, val);
+            }
+
+            void remove(const ID& id) {
+                SkASSERT(id.type() == kType);
+                fMap.remove(id);
+            }
+
+            const T& find(const ID& id) const {
+                SkASSERT(id.type() == kType);
+                T* val = fMap.find(id);
+                SkASSERT(val != nullptr);
+                return *val;
+            }
+
+        private:
+            SkTHashMap<ID, T> fMap;
+        };
+
+        // Maps ID -> T*, and keeps the T alive by reffing it.
+        template <typename T, Type kType>
+        class ReffedIDMap {
+        public:
+            ReffedIDMap() {}
+            ~ReffedIDMap() {
+                // A well-behaved client always cleans up its definitions.
+                SkASSERT(fMap.count() == 0);
+            }
+
+            void set(const ID& id, T* val) {
+                SkASSERT(id.type() == kType);
+                fMap.set(id, SkSafeRef(val));
+            }
+
+            void remove(const ID& id) {
+                SkASSERT(id.type() == kType);
+                T** val = fMap.find(id);
+                SkASSERT(val);
+                SkSafeUnref(*val);
+                fMap.remove(id);
+            }
+
+            T* find(const ID& id) const {
+                SkASSERT(id.type() == kType);
+                T** val = fMap.find(id);
+                SkASSERT(val);
+                return *val;
+            }
+
+        private:
+            SkTHashMap<ID, T*> fMap;
+        };
+
+
+        IDMap<SkMatrix        , Type::kMatrix>   fMatrix;
+        IDMap<Misc            , Type::kMisc  >   fMisc;
+        IDMap<SkPath          , Type::kPath  >   fPath;
+        IDMap<Stroke          , Type::kStroke>   fStroke;
+        ReffedIDMap<SkShader  , Type::kShader>   fShader;
+        ReffedIDMap<SkXfermode, Type::kXfermode> fXfermode;
+
+        SkCanvas* fCanvas;
+        uint64_t fNextID = 0;
+    };
+
+    Encoder* NewDecoder(SkCanvas* canvas) { return new Decoder(canvas); }
+
+    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ //
+
     class CachingEncoder final : public Encoder {
     public:
         explicit CachingEncoder(Encoder* wrapped) : fWrapped(wrapped) {}
@@ -166,194 +441,6 @@ namespace SkRemote {
         Encoder* fWrapped;
     };
 
-    Encoder* Encoder::CreateCachingEncoder(Encoder* wrapped) { return new CachingEncoder(wrapped); }
-
-    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ //
-
-    // Calls Encoder::define() when created, Encoder::undefine() when destroyed.
-    class Client::AutoID : ::SkNoncopyable {
-    public:
-        template <typename T>
-        explicit AutoID(Encoder* encoder, const T& val)
-            : fEncoder(encoder)
-            , fID(encoder->define(val)) {}
-        ~AutoID() { if (fEncoder) fEncoder->undefine(fID); }
-
-        AutoID(AutoID&& o) : fEncoder(o.fEncoder), fID(o.fID) {
-            o.fEncoder = nullptr;
-        }
-        AutoID& operator=(AutoID&&) = delete;
-
-        operator ID () const { return fID; }
-
-    private:
-        Encoder* fEncoder;
-        const ID fID;
-    };
-
-    template <typename T>
-    Client::AutoID Client::id(const T& val) { return AutoID(fEncoder, val); }
-
-    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ //
-
-    Client::Client(Encoder* encoder)
-        : SkCanvas(1,1)
-        , fEncoder(encoder)
-    {}
-
-    void Client::willSave()   { fEncoder->save(); }
-    void Client::didRestore() { fEncoder->restore(); }
-
-    void Client::didConcat   (const SkMatrix&) { this->didSetMatrix(this->getTotalMatrix()); }
-    void Client::didSetMatrix(const SkMatrix& matrix) {
-        fEncoder->setMatrix(this->id(matrix));
-    }
-
-    void Client::onDrawOval(const SkRect& oval, const SkPaint& paint) {
-        SkPath path;
-        path.addOval(oval);
-        this->onDrawPath(path, paint);
-    }
-
-    void Client::onDrawRect(const SkRect& rect, const SkPaint& paint) {
-        SkPath path;
-        path.addRect(rect);
-        this->onDrawPath(path, paint);
-    }
-
-    void Client::onDrawRRect(const SkRRect& rrect, const SkPaint& paint) {
-        SkPath path;
-        path.addRRect(rrect);
-        this->onDrawPath(path, paint);
-    }
-
-    void Client::onDrawDRRect(const SkRRect& outside,
-                              const SkRRect& inside,
-                              const SkPaint& paint) {
-        SkPath path;
-        path.addRRect(outside);
-        path.addRRect(inside, SkPath::kCCW_Direction);
-        this->onDrawPath(path, paint);
-    }
-
-    void Client::onDrawPath(const SkPath& path, const SkPaint& paint) {
-        auto p = this->id(path),
-             m = this->id(Misc::CreateFrom(paint)),
-             s = this->id(paint.getShader()),
-             x = this->id(paint.getXfermode());
-
-        if (paint.getStyle() == SkPaint::kFill_Style) {
-            fEncoder->fillPath(p, m, s, x);
-        } else {
-            // TODO: handle kStrokeAndFill_Style
-            fEncoder->strokePath(p, m, s, x, this->id(Stroke::CreateFrom(paint)));
-        }
-    }
-
-    void Client::onDrawPaint(const SkPaint& paint) {
-        SkPath path;
-        path.setFillType(SkPath::kInverseWinding_FillType);  // Either inverse FillType works fine.
-        this->onDrawPath(path, paint);
-    }
-
-    void Client::onDrawText(const void* text, size_t byteLength, SkScalar x,
-                            SkScalar y, const SkPaint& paint) {
-        // Text-as-paths is a temporary hack.
-        // TODO: send SkTextBlobs and SkTypefaces
-        SkPath path;
-        paint.getTextPath(text, byteLength, x, y, &path);
-        this->onDrawPath(path, paint);
-    }
-
-    void Client::onDrawPosText(const void* text, size_t byteLength,
-                               const SkPoint pos[], const SkPaint& paint) {
-        // Text-as-paths is a temporary hack.
-        // TODO: send SkTextBlobs and SkTypefaces
-        SkPath path;
-        paint.getPosTextPath(text, byteLength, pos, &path);
-        this->onDrawPath(path, paint);
-    }
-
-    void Client::onDrawPosTextH(const void* text, size_t byteLength,
-                                const SkScalar xpos[], SkScalar constY,
-                                const SkPaint& paint) {
-        size_t length = paint.countText(text, byteLength);
-        SkAutoTArray<SkPoint> pos(length);
-        for(size_t i = 0; i < length; ++i) {
-            pos[i].set(xpos[i], constY);
-        }
-        this->onDrawPosText(text, byteLength, &pos[0], paint);
-    }
-
-    void Client::onClipRect(const SkRect& rect, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
-        SkPath path;
-        path.addRect(rect);
-        this->onClipPath(path, op, edgeStyle);
-    }
-
-    void Client::onClipRRect(const SkRRect& rrect, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
-        SkPath path;
-        path.addRRect(rrect);
-        this->onClipPath(path, op, edgeStyle);
-    }
-
-    void Client::onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
-        fEncoder->clipPath(this->id(path), op, edgeStyle == kSoft_ClipEdgeStyle);
-    }
-
-    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ //
-
-    Server::Server(SkCanvas* canvas) : fCanvas(canvas) {}
-
-    template <typename Map, typename T>
-    ID Server::define(Type type, Map* map, const T& val) {
-        ID id(type, fNextID++);
-        map->set(id, val);
-        return id;
-    }
-
-    ID Server::define(const SkMatrix& v) { return this->define(Type::kMatrix,   &fMatrix,   v); }
-    ID Server::define(const Misc&     v) { return this->define(Type::kMisc,     &fMisc,     v); }
-    ID Server::define(const SkPath&   v) { return this->define(Type::kPath,     &fPath,     v); }
-    ID Server::define(const Stroke&   v) { return this->define(Type::kStroke,   &fStroke,   v); }
-    ID Server::define(SkShader*       v) { return this->define(Type::kShader,   &fShader,   v); }
-    ID Server::define(SkXfermode*     v) { return this->define(Type::kXfermode, &fXfermode, v); }
-
-    void Server::undefine(ID id) {
-        switch(id.type()) {
-            case Type::kMatrix:   return fMatrix  .remove(id);
-            case Type::kMisc:     return fMisc    .remove(id);
-            case Type::kPath:     return fPath    .remove(id);
-            case Type::kStroke:   return fStroke  .remove(id);
-            case Type::kShader:   return fShader  .remove(id);
-            case Type::kXfermode: return fXfermode.remove(id);
-        };
-    }
-
-    void Server::   save() { fCanvas->save(); }
-    void Server::restore() { fCanvas->restore(); }
-
-    void Server::setMatrix(ID matrix) { fCanvas->setMatrix(fMatrix.find(matrix)); }
-
-    void Server::clipPath(ID path, SkRegion::Op op, bool aa) {
-        fCanvas->clipPath(fPath.find(path), op, aa);
-    }
-    void Server::fillPath(ID path, ID misc, ID shader, ID xfermode) {
-        SkPaint paint;
-        paint.setStyle(SkPaint::kFill_Style);
-        fMisc.find(misc).applyTo(&paint);
-        paint.setShader  (fShader  .find(shader));
-        paint.setXfermode(fXfermode.find(xfermode));
-        fCanvas->drawPath(fPath.find(path), paint);
-    }
-    void Server::strokePath(ID path, ID misc, ID shader, ID xfermode, ID stroke) {
-        SkPaint paint;
-        paint.setStyle(SkPaint::kStroke_Style);
-        fMisc  .find(misc  ).applyTo(&paint);
-        fStroke.find(stroke).applyTo(&paint);
-        paint.setShader  (fShader  .find(shader));
-        paint.setXfermode(fXfermode.find(xfermode));
-        fCanvas->drawPath(fPath.find(path), paint);
-    }
+    Encoder* NewCachingEncoder(Encoder* wrapped) { return new CachingEncoder(wrapped); }
 
 } // namespace SkRemote