SkRecord strawman

src/record/SkRecorder.cpp

Index: src/record/SkRecorder.cpp
diff --git a/src/record/SkRecorder.cpp b/src/record/SkRecorder.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..1edcc52239fa950d2733bd80cb01b299d5945684
--- /dev/null
+++ b/src/record/SkRecorder.cpp
@@ -0,0 +1,224 @@
+#include "SkRecorder.h"
+#include "SkPicture.h"
+
+// SkCanvas will fail in mysterious ways if it doesn't know the real width and height.
+SkRecorder::SkRecorder(SkRecord* record, int width, int height)
+    : SkCanvas(width, height), fRecord(record) {}
+
+// To make appending to fRecord a little less verbose.
+#define APPEND(T, ...) \
+        SkNEW_PLACEMENT_ARGS(fRecord->append<SkRecords::T>(), SkRecords::T, (__VA_ARGS__))
+
+// The structs we're creating all copy their constructor arguments.  Given the way the SkRecords
+// framework works, sometimes they happen to technically be copied twice, which is fine and elided
+// into a single copy unless the class has a non-trivial copy constructor.  For classes with
+// non-trivial copy constructors, we skip the first copy (and its destruction) by wrapping the value
+// with delay_copy(), forcing the argument to be passed by const&.
+//
+// This is used below for SkBitmap, SkPaint, SkPath, and SkRegion, which all have non-trivial copy
+// constructors and destructors.  You'll know you've got a good candidate T if you see ~T() show up
+// unexpectedly on a profile of record time.  Otherwise don't bother.
+template <typename T>
+class Reference {
+public:
+    Reference(const T& x) : fX(x) {}
+    operator const T&() const { return fX; }
+private:
+    const T& fX;
+};
+
+template <typename T>
+static Reference<T> delay_copy(const T& x) { return Reference<T>(x); }
+
+// Use copy() only for optional arguments, to be copied if present or skipped if not.
+// (For most types we just pass by value and let copy constructors do their thing.)
+template <typename T>
+T* SkRecorder::copy(const T* src) {
+    if (NULL == src) {
+        return NULL;
+    }
+    return SkNEW_PLACEMENT_ARGS(fRecord->alloc<T>(), T, (*src));
+}
+
+// This copy() is for arrays.
+// It will work with POD or non-POD, though currently we only use it for POD.
+template <typename T>
+T* SkRecorder::copy(const T src[], unsigned count) {
+    if (NULL == src) {
+        return NULL;
+    }
+    T* dst = fRecord->alloc<T>(count);
+    for (unsigned i = 0; i < count; i++) {
+        SkNEW_PLACEMENT_ARGS(dst + i, T, (src[i]));
+    }
+    return dst;
+}
+
+// Specialization for copying strings, using memcpy.
+// This measured around 2x faster for copying code points,
+// but I found no corresponding speedup for other arrays.
+template <>
+char* SkRecorder::copy(const char src[], unsigned count) {
+    if (NULL == src) {
+        return NULL;
+    }
+    char* dst = fRecord->alloc<char>(count);
+    memcpy(dst, src, count);
+    return dst;
+}
+
+void SkRecorder::clear(SkColor color) {
+    APPEND(Clear, color);
+}
+
+void SkRecorder::drawPaint(const SkPaint& paint) {
+    APPEND(DrawPaint, delay_copy(paint));
+}
+
+void SkRecorder::drawPoints(PointMode mode,
+                            size_t count,
+                            const SkPoint pts[],
+                            const SkPaint& paint) {
+    APPEND(DrawPoints, mode, count, this->copy(pts, count), delay_copy(paint));
+}
+
+void SkRecorder::drawRect(const SkRect& rect, const SkPaint& paint) {
+    APPEND(DrawRect, rect, delay_copy(paint));
+}
+
+void SkRecorder::drawOval(const SkRect& oval, const SkPaint& paint) {
+    APPEND(DrawOval, oval, delay_copy(paint));
+}
+
+void SkRecorder::drawRRect(const SkRRect& rrect, const SkPaint& paint) {
+    APPEND(DrawRRect, rrect, delay_copy(paint));
+}
+
+void SkRecorder::drawPath(const SkPath& path, const SkPaint& paint) {
+    APPEND(DrawPath, delay_copy(path), delay_copy(paint));
+}
+
+void SkRecorder::drawBitmap(const SkBitmap& bitmap,
+                            SkScalar left,
+                            SkScalar top,
+                            const SkPaint* paint) {
+    APPEND(DrawBitmap, delay_copy(bitmap), left, top, this->copy(paint));
+}
+
+void SkRecorder::drawBitmapRectToRect(const SkBitmap& bitmap,
+                                      const SkRect* src,
+                                      const SkRect& dst,
+                                      const SkPaint* paint,
+                                      DrawBitmapRectFlags flags) {
+    APPEND(DrawBitmapRectToRect,
+           delay_copy(bitmap), this->copy(src), dst, this->copy(paint), flags);
+}
+
+void SkRecorder::drawBitmapMatrix(const SkBitmap& bitmap,
+                                  const SkMatrix& matrix,
+                                  const SkPaint* paint) {
+    APPEND(DrawBitmapMatrix, delay_copy(bitmap), matrix, this->copy(paint));
+}
+
+void SkRecorder::drawBitmapNine(const SkBitmap& bitmap,
+                                const SkIRect& center,
+                                const SkRect& dst,
+                                const SkPaint* paint) {
+    APPEND(DrawBitmapNine, delay_copy(bitmap), center, dst, this->copy(paint));
+}
+
+void SkRecorder::drawSprite(const SkBitmap& bitmap, int left, int top, const SkPaint* paint) {
+    APPEND(DrawSprite, delay_copy(bitmap), left, top, this->copy(paint));
+}
+
+void SkRecorder::drawText(const void* text, size_t byteLength,
+                          SkScalar x, SkScalar y, const SkPaint& paint) {
+    APPEND(DrawText,
+           this->copy((const char*)text, byteLength), byteLength, x, y, delay_copy(paint));
+}
+
+void SkRecorder::drawPosText(const void* text, size_t byteLength,
+                             const SkPoint pos[], const SkPaint& paint) {
+    const unsigned points = paint.countText(text, byteLength);
+    APPEND(DrawPosText,
+           this->copy((const char*)text, byteLength), byteLength,
+           this->copy(pos, points), delay_copy(paint));
+}
+
+void SkRecorder::drawPosTextH(const void* text, size_t byteLength,
+                              const SkScalar xpos[], SkScalar constY, const SkPaint& paint) {
+    const unsigned points = paint.countText(text, byteLength);
+    APPEND(DrawPosTextH,
+           this->copy((const char*)text, byteLength), byteLength,
+           this->copy(xpos, points), constY, delay_copy(paint));
+}
+
+void SkRecorder::drawTextOnPath(const void* text, size_t byteLength,
+                                const SkPath& path, const SkMatrix* matrix, const SkPaint& paint) {
+    APPEND(DrawTextOnPath,
+           this->copy((const char*)text, byteLength), byteLength,
+           delay_copy(path), this->copy(matrix), delay_copy(paint));
+}
+
+void SkRecorder::drawPicture(SkPicture& picture) {
+    picture.draw(this);
+}
+
+void SkRecorder::drawVertices(VertexMode vmode,
+                              int vertexCount, const SkPoint vertices[],
+                              const SkPoint texs[], const SkColor colors[],
+                              SkXfermode* xmode,
+                              const uint16_t indices[], int indexCount, const SkPaint& paint) {
+    APPEND(DrawVertices, vmode,
+                         vertexCount,
+                         this->copy(vertices, vertexCount),
+                         texs ? this->copy(texs, vertexCount) : NULL,
+                         colors ? this->copy(colors, vertexCount) : NULL,
+                         xmode,
+                         this->copy(indices, indexCount),
+                         indexCount,
+                         delay_copy(paint));
+}
+
+void SkRecorder::willSave(SkCanvas::SaveFlags flags) {
+    APPEND(Save, flags);
+}
+
+SkCanvas::SaveLayerStrategy SkRecorder::willSaveLayer(const SkRect* bounds,
+                                                      const SkPaint* paint,
+                                                      SkCanvas::SaveFlags flags) {
+    APPEND(SaveLayer, this->copy(bounds), this->copy(paint), flags);
+    return SkCanvas::kNoLayer_SaveLayerStrategy;
+}
+
+void SkRecorder::willRestore() {
+    APPEND(Restore);
+}
+
+void SkRecorder::didConcat(const SkMatrix& matrix) {
+    APPEND(Concat, matrix);
+}
+
+void SkRecorder::didSetMatrix(const SkMatrix& matrix) {
+    APPEND(SetMatrix, matrix);
+}
+
+void SkRecorder::onDrawDRRect(const SkRRect& outer, const SkRRect& inner, const SkPaint& paint) {
+    APPEND(DrawDRRect, outer, inner, delay_copy(paint));
+}
+
+void SkRecorder::onClipRect(const SkRect& rect, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
+    APPEND(ClipRect, rect, op, edgeStyle == kSoft_ClipEdgeStyle);
+}
+
+void SkRecorder::onClipRRect(const SkRRect& rrect, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
+    APPEND(ClipRRect, rrect, op, edgeStyle == kSoft_ClipEdgeStyle);
+}
+
+void SkRecorder::onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
+    APPEND(ClipPath, delay_copy(path), op, edgeStyle == kSoft_ClipEdgeStyle);
+}
+
+void SkRecorder::onClipRegion(const SkRegion& deviceRgn, SkRegion::Op op) {
+    APPEND(ClipRegion, delay_copy(deviceRgn), op);
+}