Avoid unnecessary native method calling java method

app/proguard-rules.pro

@@ -34,4 +34,3 @@
 -dontwarn org.openjsse.net.ssl.OpenJSSE
 
 -keepclasseswithmembernames class * { native <methods>;}
--keepclassmembers class com.hippo.image.Image {private <init>(long, int, int, int);}

app/src/main/cpp/image/image.c

@@ -83,6 +83,7 @@ IMAGE *create(int32_t width, int32_t height, const void *data) {
     buffer = malloc(length);
     memcpy(buffer, data, length);
 
+    // plain->isAnimated = false; this is unnecessary since we use calloc
     plain->width = width;
     plain->height = height;
     plain->buffer = buffer;

app/src/main/cpp/image/java_wrapper.c

@@ -39,32 +39,19 @@ static int jniGetFDFromFileDescriptor(JNIEnv *env, jobject fileDescriptor) {
     return fd;
 }
 
-jobject create_image_object(JNIEnv *env, void *ptr, int format, int width, int height) {
-    jclass image_clazz;
-    jmethodID constructor;
-
-    image_clazz = (*env)->FindClass(env, "com/hippo/image/Image");
-    constructor = (*env)->GetMethodID(env, image_clazz, "<init>", "(JIII)V");
-    return (*env)->NewObject(env, image_clazz, constructor,
-                             (jlong) (uintptr_t) ptr, (jint) format, (jint) width,
-                             (jint) height);
-}
-
-JNIEXPORT jobject JNICALL
+JNIEXPORT jlong JNICALL
 Java_com_hippo_image_Image_nativeDecodeFdInt(JNIEnv *env, jclass clazz, jint fd) {
     IMAGE *image = createFromFd(fd);
-    if (!image)
-        return NULL;
-    return create_image_object(env, image, image->isAnimated, image->width, image->height);
+    return (jlong) image;
 }
 
-JNIEXPORT jobject JNICALL
+JNIEXPORT jlong JNICALL
 Java_com_hippo_image_Image_nativeDecode(JNIEnv *env, jclass clazz, jobject fd) {
     return Java_com_hippo_image_Image_nativeDecodeFdInt(env, clazz,
                                                         jniGetFDFromFileDescriptor(env, fd));
 }
 
-JNIEXPORT jobject JNICALL
+JNIEXPORT jlong JNICALL
 Java_com_hippo_image_Image_nativeCreate(JNIEnv *env, jclass clazz, jobject bitmap) {
     AndroidBitmapInfo info;
     void *pixels = NULL;
@@ -75,7 +62,7 @@ Java_com_hippo_image_Image_nativeCreate(JNIEnv *env, jclass clazz, jobject bitma
 
     image = create(info.width, info.height, pixels);
     AndroidBitmap_unlockPixels(env, bitmap);
-    return create_image_object(env, image, 0, info.width, info.height);
+    return (jlong) image;
 }
 
 JNIEXPORT void JNICALL
@@ -141,10 +128,25 @@ void image_onUnload() {
     tile_buffer = NULL;
 }
 
-JNIEXPORT jobject JNICALL
+JNIEXPORT jlong JNICALL
 Java_com_hippo_image_Image_nativeDecodeAddr(JNIEnv *env, jclass clazz, jlong addr) {
     Memarea *memarea = (Memarea *) addr;
     IMAGE *image = createFromAddr(memarea->buffer, memarea->size);
     free(memarea);
-    return create_image_object(env, image, image->isAnimated, image->width, image->height);
+    return (jlong) image;
+}
+
+JNIEXPORT jint JNICALL
+Java_com_hippo_image_Image_nativeGetFormat(JNIEnv *env, jclass clazz, jlong native_ptr) {
+    return ((IMAGE *) native_ptr)->isAnimated;
+}
+
+JNIEXPORT jint JNICALL
+Java_com_hippo_image_Image_nativeGetWidth(JNIEnv *env, jclass clazz, jlong native_ptr) {
+    return ((IMAGE *) native_ptr)->width;
+}
+
+JNIEXPORT jint JNICALL
+Java_com_hippo_image_Image_nativeGetHeight(JNIEnv *env, jclass clazz, jlong native_ptr) {
+    return ((IMAGE *) native_ptr)->height;
 }

app/src/main/java/com/hippo/image/Image.java

@@ -28,29 +28,24 @@ import java.util.ArrayList;
  */
 public final class Image {
     public static final int FORMAT_NORMAL = 0;
-
     public static final int FORMAT_ANIMATED = 1;
-
     private static final ArrayList<Image> imageList = new ArrayList<>();
     private static boolean needEvictAll = false;
-
-    private final int mFormat;
-    private final int mWidth;
-    private final int mHeight;
     private long mNativePtr;
 
-    private Image(long nativePtr, int format, int width, int height) {
+    private Image(long nativePtr) {
         if (needEvictAll)
             evictAll();
-
         mNativePtr = nativePtr;
-        mFormat = format;
-        mWidth = width;
-        mHeight = height;
-
         imageList.add(this);
     }
 
+    private static Image newFromAddr(long addr) {
+        if (addr == 0)
+            return null;
+        return new Image(addr);
+    }
+
     public static void lazyEvictAll() {
         needEvictAll = true;
     }
@@ -65,7 +60,7 @@ public final class Image {
      */
     @Nullable
     public static Image decode(FileDescriptor fd, boolean partially) {
-        return nativeDecode(fd);
+        return newFromAddr(nativeDecode(fd));
     }
 
     /**
@@ -73,7 +68,7 @@ public final class Image {
      */
     @Nullable
     public static Image decode(Integer fd, boolean partially) {
-        return nativeDecodeFdInt(fd);
+        return newFromAddr(nativeDecodeFdInt(fd));
     }
 
     /**
@@ -81,7 +76,7 @@ public final class Image {
      */
     @Nullable
     public static Image decodeAddr(Long addr, boolean partially) {
-        return nativeDecodeAddr(addr);
+        return newFromAddr(nativeDecodeAddr(addr));
     }
 
     /**
@@ -89,7 +84,7 @@ public final class Image {
      */
     @Nullable
     public static Image create(Bitmap bitmap) {
-        return nativeCreate(bitmap);
+        return newFromAddr(nativeCreate(bitmap));
     }
 
     /**
@@ -100,13 +95,13 @@ public final class Image {
         return imageList.size();
     }
 
-    private static native Image nativeDecode(FileDescriptor fd);
+    private static native long nativeDecode(FileDescriptor fd);
 
-    private static native Image nativeDecodeFdInt(int fd);
+    private static native long nativeDecodeFdInt(int fd);
 
-    private static native Image nativeDecodeAddr(long addr);
+    private static native long nativeDecodeAddr(long addr);
 
-    private static native Image nativeCreate(Bitmap bitmap);
+    private static native long nativeCreate(Bitmap bitmap);
 
     private static native void nativeRender(long nativePtr,
                                             int srcX, int srcY, Bitmap dst, int dstX, int dstY,
@@ -122,25 +117,34 @@ public final class Image {
 
     private static native void nativeRecycle(long nativePtr);
 
+    private static native int nativeGetFormat(long nativePtr);
+
+    private static native int nativeGetWidth(long nativePtr);
+
+    private static native int nativeGetHeight(long nativePtr);
+
     /**
      * Return the format of the image
      */
     public int getFormat() {
-        return mFormat;
+        checkRecycled();
+        return nativeGetFormat(mNativePtr);
     }
 
     /**
      * Return the width of the image
      */
     public int getWidth() {
-        return mWidth;
+        checkRecycled();
+        return nativeGetWidth(mNativePtr);
     }
 
     /**
      * Return the height of the image
      */
     public int getHeight() {
-        return mHeight;
+        checkRecycled();
+        return nativeGetHeight(mNativePtr);
     }
 
     private void checkRecycled() {