Add support for indirect ByteBuffer

Author: vtrifonov

test-app/app/src/main/assets/app/tests/byte-buffer-test.js

@@ -1,5 +1,5 @@
 describe("Tests mapped ByteBuffer conversion", function () {
-	it("should convert ByteBuffer to ArrayBuffer", function () {
+	it("should convert ByteBuffer to ArrayBuffer [Direct ByteBuffer]", function () {
 		var bb = java.nio.ByteBuffer.allocateDirect(12);
 		var ab = ArrayBuffer.from(bb);
 		var int8arr = new Int8Array(ab);
@@ -8,7 +8,16 @@ describe("Tests mapped ByteBuffer conversion", function () {
 		expect(int32arr.length).toBe(3);
 	});
 
-	it("should share the same memory of all typed arrays", function () {
+	it("should convert ByteBuffer to ArrayBuffer [Indirect ByteBuffer]", function () {
+        var bb = java.nio.ByteBuffer.allocate(12);
+        var ab = ArrayBuffer.from(bb);
+        var int8arr = new Int8Array(ab);
+        expect(int8arr.length).toBe(12);
+        var int32arr = new Int32Array(ab);
+        expect(int32arr.length).toBe(3);
+    });
+
+	it("should share the same memory of all typed arrays [Direct ByteBuffer]", function () {
 		var bb = java.nio.ByteBuffer.allocateDirect(12);
 		var ab = ArrayBuffer.from(bb);
 		var int8arr = new Int8Array(ab);
@@ -23,13 +32,35 @@ describe("Tests mapped ByteBuffer conversion", function () {
 		expect(value).toBe(0x44332211);
 	});
 
-	it("should keep original ByteBuffer after conversion", function () {
+	it("should share the same memory of all typed arrays [Indirect ByteBuffer]", function () {
+        var bb = java.nio.ByteBuffer.allocate(12);
+        var ab = ArrayBuffer.from(bb);
+        var int8arr = new Int8Array(ab);
+        expect(int8arr.length).toBe(12);
+        var int32arr = new Int32Array(ab);
+        expect(int32arr.length).toBe(3);
+        int8arr[0] = 0x11;
+        int8arr[1] = 0x22;
+        int8arr[2] = 0x33;
+        int8arr[3] = 0x44;
+        var value = int32arr[0];
+        expect(value).toBe(0x44332211);
+    });
+
+	it("should keep original ByteBuffer after conversion [Direct ByteBuffer]", function () {
 		var bb = java.nio.ByteBuffer.allocateDirect(12);
 		var ab = ArrayBuffer.from(bb);
 		var same = bb === ab.nativeObject;
 		expect(same).toBe(true);
 	});
 
+	it("should keep original ByteBuffer after conversion [Indirect ByteBuffer]", function () {
+        var bb = java.nio.ByteBuffer.allocate(12);
+        var ab = ArrayBuffer.from(bb);
+        var same = bb === ab.nativeObject;
+        expect(same).toBe(true);
+    });
+
 	it("should throw exception when ArrayBuffer.from is called with wrong number of arguments", function () {
 		var exceptionCaught = false;
 		try {

test-app/runtime/src/main/cpp/ArrayBufferHelper.cpp

@@ -8,7 +8,8 @@ using namespace v8;
 using namespace tns;
 
 ArrayBufferHelper::ArrayBufferHelper()
-    : m_objectManager(nullptr), m_ByteBufferClass(nullptr), m_isDirectMethodID(nullptr) {
+        : m_objectManager(nullptr), m_ByteBufferClass(nullptr), m_isDirectMethodID(nullptr),
+          m_remainingMethodID(nullptr), m_getMethodID(nullptr) {
 }
 
 void ArrayBufferHelper::CreateConvertFunctions(Isolate* isolate, const Local<Object>& global, ObjectManager* objectManager) {
@@ -82,14 +83,34 @@ void ArrayBufferHelper::CreateFromCallbackImpl(const FunctionCallbackInfo<Value>
 
     auto isDirectBuffer = ret == JNI_TRUE;
 
-    if (!isDirectBuffer) {
-        throw NativeScriptException("Direct ByteBuffer expected)");
-    }
+    Local<ArrayBuffer> arrayBuffer;
+
+    if (isDirectBuffer) {
+        auto data = env.GetDirectBufferAddress(obj);
+        auto size = env.GetDirectBufferCapacity(obj);
+
+        arrayBuffer = ArrayBuffer::New(isolate, data, size);
+    } else {
+        if (m_remainingMethodID == nullptr) {
+            m_remainingMethodID = env.GetMethodID(m_ByteBufferClass, "remaining", "()I");
+            assert(m_remainingMethodID != nullptr);
+        }
+
+        int bufferRemainingSize = env.CallIntMethod(obj, m_remainingMethodID);
 
-    auto data = env.GetDirectBufferAddress(obj);
-    auto size = env.GetDirectBufferCapacity(obj);
+        if (m_getMethodID == nullptr) {
+            m_getMethodID = env.GetMethodID(m_ByteBufferClass, "get", "([BII)Ljava/nio/ByteBuffer;");
+            assert(m_getMethodID != nullptr);
+        }
+
+        jbyteArray byteArray = env.NewByteArray(bufferRemainingSize);
+        env.CallObjectMethod(obj, m_getMethodID, byteArray, 0, bufferRemainingSize);
+
+        auto buffer = env.GetByteArrayElements(byteArray, 0);
+        arrayBuffer = ArrayBuffer::New(isolate, bufferRemainingSize);
+        memcpy(arrayBuffer->GetContents().Data(), buffer, bufferRemainingSize);
+    }
 
-    auto arrayBuffer = ArrayBuffer::New(isolate, data, size);
     auto ctx = isolate->GetCurrentContext();
     arrayBuffer->Set(ctx, ArgConverter::ConvertToV8String(isolate, "nativeObject"), argObj);
 

test-app/runtime/src/main/cpp/ArrayBufferHelper.h

@@ -5,24 +5,25 @@
 #include "ObjectManager.h"
 
 namespace tns {
-class ArrayBufferHelper {
-    public:
-        ArrayBufferHelper();
+    class ArrayBufferHelper {
+        public:
+            ArrayBufferHelper();
 
-        void CreateConvertFunctions(v8::Isolate* isolate, const v8::Local<v8::Object>& global, ObjectManager* objectManager);
+            void CreateConvertFunctions(v8::Isolate* isolate, const v8::Local<v8::Object>& global, ObjectManager* objectManager);
 
-    private:
+        private:
 
-        static void CreateFromCallbackStatic(const v8::FunctionCallbackInfo<v8::Value>& info);
+            static void CreateFromCallbackStatic(const v8::FunctionCallbackInfo<v8::Value>& info);
 
-        void CreateFromCallbackImpl(const v8::FunctionCallbackInfo<v8::Value>& info);
+            void CreateFromCallbackImpl(const v8::FunctionCallbackInfo<v8::Value>& info);
 
-        ObjectManager* m_objectManager;
+            ObjectManager* m_objectManager;
 
-        jclass m_ByteBufferClass;
-
-        jmethodID m_isDirectMethodID;
-};
+            jclass m_ByteBufferClass;
+            jmethodID m_isDirectMethodID;
+            jmethodID m_remainingMethodID;
+            jmethodID m_getMethodID;
+    };
 }