Make Flattenable not virtual

Fallout from the Flattenable change, update all its uses.

Additionnaly, fix/tighten size checks when (un)flatten()ing
things.

Removed the assumption by some flattenables (e.g.: Fence)
that the size passed to them would be exact (it can
and will be larger in some cases)

The code in Parcel is a bit complicated so that we don't
have to expose the full implementation (and also to
keep the code smallish).

Change-Id: I0bf1c8aca2a3128491b4f45510bc46667e566dde

6 files changed, 79 insertions, 34 deletions

diff --git a/include/binder/Parcel.h b/include/binder/Parcel.h
index 3ff95d2..7a782f5 100644
--- a/include/binder/Parcel.h
+++ b/include/binder/Parcel.h
@@ -27,8 +27,8 @@
 // ---------------------------------------------------------------------------
 namespace android {
 
+template <typename T> class Flattenable;
 template <typename T> class LightFlattenable;
-class Flattenable;
 class IBinder;
 class IPCThreadState;
 class ProcessState;
@@ -37,8 +37,7 @@ class TextOutput;
 
 struct flat_binder_object;  // defined in support_p/binder_module.h
 
-class Parcel
-{
+class Parcel {
 public:
     class ReadableBlob;
     class WritableBlob;
@@ -102,7 +101,9 @@ public:
     status_t            writeString16(const char16_t* str, size_t len);
     status_t            writeStrongBinder(const sp<IBinder>& val);
     status_t            writeWeakBinder(const wp<IBinder>& val);
-    status_t            write(const Flattenable& val);
+
+    template<typename T>
+    status_t            write(const Flattenable<T>& val);
 
     template<typename T>
     status_t            write(const LightFlattenable<T>& val);
@@ -157,7 +158,9 @@ public:
     const char16_t*     readString16Inplace(size_t* outLen) const;
     sp<IBinder>         readStrongBinder() const;
     wp<IBinder>         readWeakBinder() const;
-    status_t            read(Flattenable& val) const;
+
+    template<typename T>
+    status_t            read(Flattenable<T>& val) const;
 
     template<typename T>
     status_t            read(LightFlattenable<T>& val) const;
@@ -260,6 +263,39 @@ private:
         size_t mSize;
     };
 
+    class FlattenableHelperInterface {
+    protected:
+        ~FlattenableHelperInterface() { }
+    public:
+        virtual size_t getFlattenedSize() const = 0;
+        virtual size_t getFdCount() const = 0;
+        virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const = 0;
+        virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) = 0;
+    };
+
+    template<typename T>
+    class FlattenableHelper : public FlattenableHelperInterface {
+        friend class Parcel;
+        const Flattenable<T>& val;
+        explicit FlattenableHelper(const Flattenable<T>& val) : val(val) { }
+
+    public:
+        virtual size_t getFlattenedSize() const {
+            return val.getFlattenedSize();
+        }
+        virtual size_t getFdCount() const {
+            return val.getFdCount();
+        }
+        virtual status_t flatten(void* buffer, size_t size, int* fds, size_t count) const {
+            return val.flatten(buffer, size, fds, count);
+        }
+        virtual status_t unflatten(void const* buffer, size_t size, int const* fds, size_t count) {
+            return const_cast<Flattenable<T>&>(val).unflatten(buffer, size, fds, count);
+        }
+    };
+    status_t write(const FlattenableHelperInterface& val);
+    status_t read(FlattenableHelperInterface& val) const;
+
 public:
     class ReadableBlob : public Blob {
         friend class Parcel;
@@ -277,8 +313,14 @@ public:
 // ---------------------------------------------------------------------------
 
 template<typename T>
+status_t Parcel::write(const Flattenable<T>& val) {
+    const FlattenableHelper<T> helper(val);
+    return write(helper);
+}
+
+template<typename T>
 status_t Parcel::write(const LightFlattenable<T>& val) {
-    size_t size(val.getSize());
+    size_t size(val.getFlattenedSize());
     if (!val.isFixedSize()) {
         status_t err = writeInt32(size);
         if (err != NO_ERROR) {
@@ -287,17 +329,24 @@ status_t Parcel::write(const LightFlattenable<T>& val) {
     }
     if (size) {
         void* buffer = writeInplace(size);
-        return buffer == NULL ? NO_MEMORY :
-                val.flatten(buffer);
+        if (buffer == NULL)
+            return NO_MEMORY;
+        return val.flatten(buffer, size);
     }
     return NO_ERROR;
 }
 
 template<typename T>
+status_t Parcel::read(Flattenable<T>& val) const {
+    FlattenableHelper<T> helper(val);
+    return read(helper);
+}
+
+template<typename T>
 status_t Parcel::read(LightFlattenable<T>& val) const {
     size_t size;
     if (val.isFixedSize()) {
-        size = val.getSize();
+        size = val.getFlattenedSize();
     } else {
         int32_t s;
         status_t err = readInt32(&s);
diff --git a/include/gui/IGraphicBufferProducer.h b/include/gui/IGraphicBufferProducer.h
index 9677962..033c727 100644
--- a/include/gui/IGraphicBufferProducer.h
+++ b/include/gui/IGraphicBufferProducer.h
@@ -105,7 +105,8 @@ public:
     // and height of the window and current transform applied to buffers,
     // respectively.
 
-    struct QueueBufferInput : public Flattenable {
+    struct QueueBufferInput : public Flattenable<QueueBufferInput> {
+        friend class Flattenable<QueueBufferInput>;
         inline QueueBufferInput(const Parcel& parcel);
         inline QueueBufferInput(int64_t timestamp,
                 const Rect& crop, int scalingMode, uint32_t transform, bool async,
@@ -123,13 +124,11 @@ public:
             *outFence = fence;
         }
 
-        // 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);
+        // Flattenable protocol
+        size_t getFlattenedSize() const;
+        size_t getFdCount() const;
+        status_t flatten(void*& buffer, size_t& size, int*& fds, size_t& count) const;
+        status_t unflatten(void const*& buffer, size_t& size, int const*& fds, size_t& count);
 
     private:
         int64_t timestamp;
diff --git a/include/gui/Sensor.h b/include/gui/Sensor.h
index 2af2307..9197372 100644
--- a/include/gui/Sensor.h
+++ b/include/gui/Sensor.h
@@ -70,8 +70,8 @@ public:
 
     // LightFlattenable protocol
     inline bool isFixedSize() const { return false; }
-    size_t getSize() const;
-    status_t flatten(void* buffer) const;
+    size_t getFlattenedSize() const;
+    status_t flatten(void* buffer, size_t size) const;
     status_t unflatten(void const* buffer, size_t size);
 
 private:
diff --git a/include/ui/Fence.h b/include/ui/Fence.h
index 60156e7..20466b6 100644
--- a/include/ui/Fence.h
+++ b/include/ui/Fence.h
@@ -36,7 +36,7 @@ namespace android {
 // ===========================================================================
 
 class Fence
-    : public LightRefBase<Fence>, public Flattenable
+    : public LightRefBase<Fence>, public Flattenable<Fence>
 {
 public:
     static const sp<Fence> NO_FENCE;
@@ -96,15 +96,13 @@ public:
     // Flattenable interface
     size_t getFlattenedSize() const;
     size_t getFdCount() const;
-    status_t flatten(void* buffer, size_t size,
-            int fds[], size_t count) const;
-    status_t unflatten(void const* buffer, size_t size,
-            int fds[], size_t count);
+    status_t flatten(void*& buffer, size_t& size, int*& fds, size_t& count) const;
+    status_t unflatten(void const*& buffer, size_t& size, int const*& fds, size_t& count);
 
 private:
     // Only allow instantiation using ref counting.
     friend class LightRefBase<Fence>;
-    virtual ~Fence();
+    ~Fence();
 
     // Disallow copying
     Fence(const Fence& rhs);
diff --git a/include/ui/GraphicBuffer.h b/include/ui/GraphicBuffer.h
index e5ad1e0..8184b7d 100644
--- a/include/ui/GraphicBuffer.h
+++ b/include/ui/GraphicBuffer.h
@@ -39,8 +39,9 @@ class GraphicBufferMapper;
 
 class GraphicBuffer
     : public ANativeObjectBase< ANativeWindowBuffer, GraphicBuffer, RefBase >,
-      public Flattenable
+      public Flattenable<GraphicBuffer>
 {
+    friend class Flattenable<GraphicBuffer>;
 public:
 
     enum {
@@ -106,7 +107,7 @@ public:
     static void dumpAllocationsToSystemLog();
 
 private:
-    virtual ~GraphicBuffer();
+    ~GraphicBuffer();
 
     enum {
         ownNone   = 0,
@@ -136,13 +137,11 @@ private:
 
     void free_handle();
 
-    // Flattenable interface
+    // Flattenable protocol
     size_t getFlattenedSize() const;
     size_t getFdCount() const;
-    status_t flatten(void* buffer, size_t size,
-            int fds[], size_t count) const;
-    status_t unflatten(void const* buffer, size_t size,
-            int fds[], size_t count);
+    status_t flatten(void*& buffer, size_t& size, int*& fds, size_t& count) const;
+    status_t unflatten(void const*& buffer, size_t& size, int const*& fds, size_t& count);
 
 
     GraphicBufferMapper& mBufferMapper;
diff --git a/include/ui/Region.h b/include/ui/Region.h
index ce91f3b..d906dbb 100644
--- a/include/ui/Region.h
+++ b/include/ui/Region.h
@@ -136,8 +136,8 @@ public:
             void        addRectUnchecked(int l, int t, int r, int b);
 
     inline  bool        isFixedSize() const { return false; }
-            size_t      getSize() const;
-            status_t    flatten(void* buffer) const;
+            size_t      getFlattenedSize() const;
+            status_t    flatten(void* buffer, size_t size) const;
             status_t    unflatten(void const* buffer, size_t size);
 
     void        dump(String8& out, const char* what, uint32_t flags=0) const;