improve [un]marshalling of non-binder objects

this change introduces a new class LightFlattenable<> which is
a protocol to flatten simple objects that don't require
binders or file descriptors; the benefit of this protocol is that
it doesn't require the objects to have a virtual table and give us
a consitant way of doing this.

we also introduce an implementation of this protocol for
POD structures, LightFlattenablePod<>.

Parcel has been update to handle this protocol automatically.

Sensor, Rect, Point and Region now use this new protocol.

Change-Id: Icb3ce7fa1d785249eb666f39c2129f2fc143ea4a

1 files changed, 7 insertions, 9 deletions

diff --git a/include/gui/Sensor.h b/include/gui/Sensor.h
index e59757a..2af2307 100644
--- a/include/gui/Sensor.h
+++ b/include/gui/Sensor.h
@@ -41,7 +41,7 @@ class Parcel;
 
 // ----------------------------------------------------------------------------
 
-class Sensor : public ASensor, public Flattenable
+class Sensor : public ASensor, public LightFlattenable<Sensor>
 {
 public:
     enum {
@@ -54,7 +54,7 @@ public:
 
             Sensor();
             Sensor(struct sensor_t const* hwSensor);
-    virtual ~Sensor();
+            ~Sensor();
 
     const String8& getName() const;
     const String8& getVendor() const;
@@ -68,13 +68,11 @@ public:
     nsecs_t getMinDelayNs() const;
     int32_t getVersion() const;
 
-    // Flattenable interface
-    virtual size_t getFlattenedSize() const;
-    virtual size_t getFdCount() const;
-    virtual status_t flatten(void* buffer, size_t size,
-            int fds[], size_t count) const;
-    virtual status_t unflatten(void const* buffer, size_t size,
-            int fds[], size_t count);
+    // LightFlattenable protocol
+    inline bool isFixedSize() const { return false; }
+    size_t getSize() const;
+    status_t flatten(void* buffer) const;
+    status_t unflatten(void const* buffer, size_t size);
 
 private:
     String8 mName;