Don't store empty objects on SF traces

Proto3 doesn't store default values for object, however, it stored the
object start-end tags if an empty object was created.

Do not create objects when they are empty

Test: Flash a device. Record SF trace. Open them in the new winscope
version with "display defaults" unchecked. Check if there are no empty
objects

Change-Id: I3f48047e43e9c62c572d5b83e63a0f96527ef146
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index daef7c6..2c73b53 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -2042,26 +2042,26 @@
     }
 
     LayerProtoHelper::writeToProto(state.activeTransparentRegion_legacy,
-                                   layerInfo->mutable_transparent_region());
-    LayerProtoHelper::writeToProto(visibleRegion, layerInfo->mutable_visible_region());
-    LayerProtoHelper::writeToProto(surfaceDamageRegion, layerInfo->mutable_damage_region());
+                                   [&]() { return layerInfo->mutable_transparent_region(); });
+    LayerProtoHelper::writeToProto(visibleRegion,
+                                   [&]() { return layerInfo->mutable_visible_region(); });
+    LayerProtoHelper::writeToProto(surfaceDamageRegion,
+                                   [&]() { return layerInfo->mutable_damage_region(); });
 
     layerInfo->set_layer_stack(getLayerStack());
     layerInfo->set_z(state.z);
 
-    PositionProto* position = layerInfo->mutable_position();
-    position->set_x(transform.tx());
-    position->set_y(transform.ty());
+    LayerProtoHelper::writePositionToProto(transform.tx(), transform.ty(),
+                                           [&]() { return layerInfo->mutable_position(); });
 
-    PositionProto* requestedPosition = layerInfo->mutable_requested_position();
-    requestedPosition->set_x(requestedTransform.tx());
-    requestedPosition->set_y(requestedTransform.ty());
+    LayerProtoHelper::writePositionToProto(requestedTransform.tx(), requestedTransform.ty(), [&]() {
+        return layerInfo->mutable_requested_position();
+    });
 
-    SizeProto* size = layerInfo->mutable_size();
-    size->set_w(state.active_legacy.w);
-    size->set_h(state.active_legacy.h);
+    LayerProtoHelper::writeSizeToProto(state.active_legacy.w, state.active_legacy.h,
+                                       [&]() { return layerInfo->mutable_size(); });
 
-    LayerProtoHelper::writeToProto(state.crop_legacy, layerInfo->mutable_crop());
+    LayerProtoHelper::writeToProto(state.crop_legacy, [&]() { return layerInfo->mutable_crop(); });
     layerInfo->set_corner_radius(getRoundedCornerState().radius);
 
     layerInfo->set_is_opaque(isOpaque(state));
@@ -2071,8 +2071,9 @@
     layerInfo->set_dataspace(dataspaceDetails(static_cast<android_dataspace>(mCurrentDataSpace)));
 
     layerInfo->set_pixel_format(decodePixelFormat(getPixelFormat()));
-    LayerProtoHelper::writeToProto(getColor(), layerInfo->mutable_color());
-    LayerProtoHelper::writeToProto(state.color, layerInfo->mutable_requested_color());
+    LayerProtoHelper::writeToProto(getColor(), [&]() { return layerInfo->mutable_color(); });
+    LayerProtoHelper::writeToProto(state.color,
+                                   [&]() { return layerInfo->mutable_requested_color(); });
     layerInfo->set_flags(state.flags);
 
     LayerProtoHelper::writeToProto(transform, layerInfo->mutable_transform());
@@ -2094,7 +2095,8 @@
 
     auto buffer = mActiveBuffer;
     if (buffer != nullptr) {
-        LayerProtoHelper::writeToProto(buffer, layerInfo->mutable_active_buffer());
+        LayerProtoHelper::writeToProto(buffer,
+                                       [&]() { return layerInfo->mutable_active_buffer(); });
         LayerProtoHelper::writeToProto(ui::Transform(mCurrentTransform),
                                        layerInfo->mutable_buffer_transform());
     }
@@ -2118,9 +2120,11 @@
         (*protoMap)[entry.first] = std::string(entry.second.cbegin(), entry.second.cend());
     }
     LayerProtoHelper::writeToProto(mEffectiveTransform, layerInfo->mutable_effective_transform());
-    LayerProtoHelper::writeToProto(mSourceBounds, layerInfo->mutable_source_bounds());
-    LayerProtoHelper::writeToProto(mScreenBounds, layerInfo->mutable_screen_bounds());
-    LayerProtoHelper::writeToProto(mBounds, layerInfo->mutable_bounds());
+    LayerProtoHelper::writeToProto(mSourceBounds,
+                                   [&]() { return layerInfo->mutable_source_bounds(); });
+    LayerProtoHelper::writeToProto(mScreenBounds,
+                                   [&]() { return layerInfo->mutable_screen_bounds(); });
+    LayerProtoHelper::writeToProto(mBounds, [&]() { return layerInfo->mutable_bounds(); });
 }
 
 void Layer::writeToProto(LayerProto* layerInfo, const sp<DisplayDevice>& displayDevice) {
@@ -2134,10 +2138,10 @@
     const auto& compositionState = outputLayer->getState();
 
     const Rect& frame = compositionState.displayFrame;
-    LayerProtoHelper::writeToProto(frame, layerInfo->mutable_hwc_frame());
+    LayerProtoHelper::writeToProto(frame, [&]() { return layerInfo->mutable_hwc_frame(); });
 
     const FloatRect& crop = compositionState.sourceCrop;
-    LayerProtoHelper::writeToProto(crop, layerInfo->mutable_hwc_crop());
+    LayerProtoHelper::writeToProto(crop, [&]() { return layerInfo->mutable_hwc_crop(); });
 
     const int32_t transform =
             getCompositionLayer() ? static_cast<int32_t>(compositionState.bufferTransform) : 0;
diff --git a/services/surfaceflinger/LayerProtoHelper.cpp b/services/surfaceflinger/LayerProtoHelper.cpp
index 3289e8f..02383a6 100644
--- a/services/surfaceflinger/LayerProtoHelper.cpp
+++ b/services/surfaceflinger/LayerProtoHelper.cpp
@@ -18,53 +18,106 @@
 
 namespace android {
 namespace surfaceflinger {
-void LayerProtoHelper::writeToProto(const Region& region, RegionProto* regionProto) {
+
+void LayerProtoHelper::writePositionToProto(const float x, const float y,
+                                            std::function<PositionProto*()> getPositionProto) {
+    if (x != 0 || y != 0) {
+        // Use a lambda do avoid writing the object header when the object is empty
+        PositionProto* position = getPositionProto();
+        position->set_x(x);
+        position->set_y(y);
+    }
+}
+
+void LayerProtoHelper::writeSizeToProto(const uint32_t w, const uint32_t h,
+                                        std::function<SizeProto*()> getSizeProto) {
+    if (w != 0 || h != 0) {
+        // Use a lambda do avoid writing the object header when the object is empty
+        SizeProto* size = getSizeProto();
+        size->set_w(w);
+        size->set_h(h);
+    }
+}
+
+void LayerProtoHelper::writeToProto(const Region& region,
+                                    std::function<RegionProto*()> getRegionProto) {
+    if (region.isEmpty()) {
+        return;
+    }
+
     Region::const_iterator head = region.begin();
     Region::const_iterator const tail = region.end();
+    // Use a lambda do avoid writing the object header when the object is empty
+    RegionProto* regionProto = getRegionProto();
     uint64_t address = reinterpret_cast<uint64_t>(&region);
     regionProto->set_id(address);
     while (head != tail) {
-        RectProto* rectProto = regionProto->add_rect();
-        writeToProto(*head, rectProto);
+        std::function<RectProto*()> getProtoRect = [&]() { return regionProto->add_rect(); };
+        writeToProto(*head, getProtoRect);
         head++;
     }
 }
 
-void LayerProtoHelper::writeToProto(const Rect& rect, RectProto* rectProto) {
-    rectProto->set_left(rect.left);
-    rectProto->set_top(rect.top);
-    rectProto->set_bottom(rect.bottom);
-    rectProto->set_right(rect.right);
+void LayerProtoHelper::writeToProto(const Rect& rect, std::function<RectProto*()> getRectProto) {
+    if (rect.left != 0 || rect.right != 0 || rect.top != 0 || rect.bottom != 0) {
+        // Use a lambda do avoid writing the object header when the object is empty
+        RectProto* rectProto = getRectProto();
+        rectProto->set_left(rect.left);
+        rectProto->set_top(rect.top);
+        rectProto->set_bottom(rect.bottom);
+        rectProto->set_right(rect.right);
+    }
 }
 
-void LayerProtoHelper::writeToProto(const FloatRect& rect, FloatRectProto* rectProto) {
-    rectProto->set_left(rect.left);
-    rectProto->set_top(rect.top);
-    rectProto->set_bottom(rect.bottom);
-    rectProto->set_right(rect.right);
+void LayerProtoHelper::writeToProto(const FloatRect& rect,
+                                    std::function<FloatRectProto*()> getFloatRectProto) {
+    if (rect.left != 0 || rect.right != 0 || rect.top != 0 || rect.bottom != 0) {
+        // Use a lambda do avoid writing the object header when the object is empty
+        FloatRectProto* rectProto = getFloatRectProto();
+        rectProto->set_left(rect.left);
+        rectProto->set_top(rect.top);
+        rectProto->set_bottom(rect.bottom);
+        rectProto->set_right(rect.right);
+    }
 }
 
-void LayerProtoHelper::writeToProto(const half4 color, ColorProto* colorProto) {
-    colorProto->set_r(color.r);
-    colorProto->set_g(color.g);
-    colorProto->set_b(color.b);
-    colorProto->set_a(color.a);
+void LayerProtoHelper::writeToProto(const half4 color, std::function<ColorProto*()> getColorProto) {
+    if (color.r != 0 || color.g != 0 || color.b != 0 || color.a != 0) {
+        // Use a lambda do avoid writing the object header when the object is empty
+        ColorProto* colorProto = getColorProto();
+        colorProto->set_r(color.r);
+        colorProto->set_g(color.g);
+        colorProto->set_b(color.b);
+        colorProto->set_a(color.a);
+    }
 }
 
 void LayerProtoHelper::writeToProto(const ui::Transform& transform,
                                     TransformProto* transformProto) {
-    transformProto->set_dsdx(transform[0][0]);
-    transformProto->set_dtdx(transform[0][1]);
-    transformProto->set_dsdy(transform[1][0]);
-    transformProto->set_dtdy(transform[1][1]);
+    const uint32_t type = transform.getType();
+    transformProto->set_type(type);
+
+    if (type &
+        (ui::Transform::SCALE | ui::Transform::ROTATE | ui::Transform::TRANSLATE |
+         ui::Transform::UNKNOWN)) {
+        transformProto->set_dsdx(transform[0][0]);
+        transformProto->set_dtdx(transform[0][1]);
+        transformProto->set_dsdy(transform[1][0]);
+        transformProto->set_dtdy(transform[1][1]);
+    }
 }
 
 void LayerProtoHelper::writeToProto(const sp<GraphicBuffer>& buffer,
-                                    ActiveBufferProto* activeBufferProto) {
-    activeBufferProto->set_width(buffer->getWidth());
-    activeBufferProto->set_height(buffer->getHeight());
-    activeBufferProto->set_stride(buffer->getStride());
-    activeBufferProto->set_format(buffer->format);
+                                    std::function<ActiveBufferProto*()> getActiveBufferProto) {
+    if (buffer->getWidth() != 0 || buffer->getHeight() != 0 || buffer->getStride() != 0 ||
+        buffer->format != 0) {
+        // Use a lambda do avoid writing the object header when the object is empty
+        ActiveBufferProto* activeBufferProto = getActiveBufferProto();
+        activeBufferProto->set_width(buffer->getWidth());
+        activeBufferProto->set_height(buffer->getHeight());
+        activeBufferProto->set_stride(buffer->getStride());
+        activeBufferProto->set_format(buffer->format);
+    }
 }
 
 } // namespace surfaceflinger
diff --git a/services/surfaceflinger/LayerProtoHelper.h b/services/surfaceflinger/LayerProtoHelper.h
index 6df5aea..dca9a5e 100644
--- a/services/surfaceflinger/LayerProtoHelper.h
+++ b/services/surfaceflinger/LayerProtoHelper.h
@@ -26,12 +26,18 @@
 namespace surfaceflinger {
 class LayerProtoHelper {
 public:
-    static void writeToProto(const Rect& rect, RectProto* rectProto);
-    static void writeToProto(const FloatRect& rect, FloatRectProto* rectProto);
-    static void writeToProto(const Region& region, RegionProto* regionProto);
-    static void writeToProto(const half4 color, ColorProto* colorProto);
+    static void writePositionToProto(const float x, const float y,
+                                     std::function<PositionProto*()> getPositionProto);
+    static void writeSizeToProto(const uint32_t w, const uint32_t h,
+                                 std::function<SizeProto*()> getSizeProto);
+    static void writeToProto(const Rect& rect, std::function<RectProto*()> getRectProto);
+    static void writeToProto(const FloatRect& rect,
+                             std::function<FloatRectProto*()> getFloatRectProto);
+    static void writeToProto(const Region& region, std::function<RegionProto*()> getRegionProto);
+    static void writeToProto(const half4 color, std::function<ColorProto*()> getColorProto);
     static void writeToProto(const ui::Transform& transform, TransformProto* transformProto);
-    static void writeToProto(const sp<GraphicBuffer>& buffer, ActiveBufferProto* activeBufferProto);
+    static void writeToProto(const sp<GraphicBuffer>& buffer,
+                             std::function<ActiveBufferProto*()> getActiveBufferProto);
 };
 
 } // namespace surfaceflinger
diff --git a/services/surfaceflinger/layerproto/layers.proto b/services/surfaceflinger/layerproto/layers.proto
index faf0c54..a0fb0a0 100644
--- a/services/surfaceflinger/layerproto/layers.proto
+++ b/services/surfaceflinger/layerproto/layers.proto
@@ -113,6 +113,7 @@
   float dtdx = 2;
   float dsdy = 3;
   float dtdy = 4;
+  int32 type = 5;
 }
 
 message RegionProto {