Untangle MediaPlayer, MediaRecorder, MediaScanner and MediaMetadataRetriever JNI

code, so that creating one of those doesn't initialize all the others. Shaves
a hundred milliseconds or so off music app startup time.

6 files changed, 157 insertions, 134 deletions

diff --git a/media/jni/android_media_AmrInputStream.cpp b/media/jni/android_media_AmrInputStream.cpp
index 51cb6c7..c4dd07e 100644
--- a/media/jni/android_media_AmrInputStream.cpp
+++ b/media/jni/android_media_AmrInputStream.cpp
@@ -169,13 +169,6 @@ static JNINativeMethod gMethods[] = {
 int register_android_media_AmrInputStream(JNIEnv *env)
 {
     const char* const kClassPathName = "android/media/AmrInputStream";
-    jclass clazz;
-
-    clazz = env->FindClass(kClassPathName);
-    if (clazz == NULL) {
-        LOGE("Can't find %s", kClassPathName);
-        return -1;
-    }
 
     return AndroidRuntime::registerNativeMethods(env,
             kClassPathName, gMethods, NELEM(gMethods));
diff --git a/media/jni/android_media_MediaMetadataRetriever.cpp b/media/jni/android_media_MediaMetadataRetriever.cpp
index 4624a18..49f8cdd 100644
--- a/media/jni/android_media_MediaMetadataRetriever.cpp
+++ b/media/jni/android_media_MediaMetadataRetriever.cpp
@@ -40,6 +40,7 @@ struct fields_t {
 
 static fields_t fields;
 static Mutex sLock;
+static const char* const kClassPathName = "android/media/MediaMetadataRetriever";
 
 static void process_media_retriever_call(JNIEnv *env, status_t opStatus, const char* exception, const char *message)
 {
@@ -269,6 +270,36 @@ static void android_media_MediaMetadataRetriever_native_finalize(JNIEnv *env, jo
     android_media_MediaMetadataRetriever_release(env, thiz);
 }
 
+// This function gets a field ID, which in turn causes class initialization.
+// It is called from a static block in MediaMetadataRetriever, which won't run until the
+// first time an instance of this class is used.
+static void android_media_MediaMetadataRetriever_native_init(JNIEnv *env)
+{
+    jclass clazz = env->FindClass(kClassPathName);
+    if (clazz == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find android/media/MediaMetadataRetriever");
+        return;
+    }
+
+    fields.context = env->GetFieldID(clazz, "mNativeContext", "I");
+    if (fields.context == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find MediaMetadataRetriever.mNativeContext");
+        return;
+    }
+
+    fields.bitmapClazz = env->FindClass("android/graphics/Bitmap");
+    if (fields.bitmapClazz == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find android/graphics/Bitmap");
+        return;
+    }
+
+    fields.bitmapConstructor = env->GetMethodID(fields.bitmapClazz, "<init>", "(IZ[B)V");
+    if (fields.bitmapConstructor == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find Bitmap constructor");
+        return;
+    }
+}
+
 static void android_media_MediaMetadataRetriever_native_setup(JNIEnv *env, jobject thiz)
 {
     LOGV("native_setup");
@@ -292,36 +323,13 @@ static JNINativeMethod nativeMethods[] = {
         {"release",         "()V", (void *)android_media_MediaMetadataRetriever_release},
         {"native_finalize", "()V", (void *)android_media_MediaMetadataRetriever_native_finalize},
         {"native_setup",    "()V", (void *)android_media_MediaMetadataRetriever_native_setup},
+        {"native_init",     "()V", (void *)android_media_MediaMetadataRetriever_native_init},
 };
 
-// Register native mehtods with Android runtime environment
+// This function only registers the native methods, and is called from
+// JNI_OnLoad in android_media_MediaPlayer.cpp
 int register_android_media_MediaMetadataRetriever(JNIEnv *env)
 {
-    static const char* const kClassPathName = "android/media/MediaMetadataRetriever";
-    jclass clazz = env->FindClass(kClassPathName);
-    if (clazz == NULL) {
-        LOGE("Can't find class: %s", kClassPathName);
-        return -1;
-    }
-
-    fields.context = env->GetFieldID(clazz, "mNativeContext", "I");
-    if (fields.context == NULL) {
-        LOGE("Can't find MediaMetadataRetriever.mNativeContext");
-        return -1;
-    }
-
-    fields.bitmapClazz = env->FindClass("android/graphics/Bitmap");
-    if (fields.bitmapClazz == NULL) {
-        LOGE("Bitmap class is not found");
-        return -1;
-    }
-
-    fields.bitmapConstructor = env->GetMethodID(fields.bitmapClazz, "<init>", "(IZ[B)V");
-    if (fields.bitmapConstructor == NULL) {
-        LOGE("Bitmap constructor is not found");
-        return -1;
-    }
-
     return AndroidRuntime::registerNativeMethods
-    (env, kClassPathName, nativeMethods, NELEM(nativeMethods));
+        (env, kClassPathName, nativeMethods, NELEM(nativeMethods));
 }
diff --git a/media/jni/android_media_MediaPlayer.cpp b/media/jni/android_media_MediaPlayer.cpp
index d26d039..df98de5 100644
--- a/media/jni/android_media_MediaPlayer.cpp
+++ b/media/jni/android_media_MediaPlayer.cpp
@@ -511,6 +511,51 @@ android_media_MediaPlayer_getMetadata(JNIEnv *env, jobject thiz, jboolean update
     return media_player->getMetadata(update_only, apply_filter, metadata) == OK;
 }
 
+// This function gets some field IDs, which in turn causes class initialization.
+// It is called from a static block in MediaPlayer, which won't run until the
+// first time an instance of this class is used.
+static void
+android_media_MediaPlayer_native_init(JNIEnv *env)
+{
+    jclass clazz;
+
+    clazz = env->FindClass("android/media/MediaPlayer");
+    if (clazz == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find android/media/MediaPlayer");
+        return;
+    }
+
+    fields.context = env->GetFieldID(clazz, "mNativeContext", "I");
+    if (fields.context == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find MediaPlayer.mNativeContext");
+        return;
+    }
+
+    fields.post_event = env->GetStaticMethodID(clazz, "postEventFromNative",
+                                               "(Ljava/lang/Object;IIILjava/lang/Object;)V");
+    if (fields.post_event == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find MediaPlayer.postEventFromNative");
+        return;
+    }
+
+    fields.surface = env->GetFieldID(clazz, "mSurface", "Landroid/view/Surface;");
+    if (fields.surface == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find MediaPlayer.mSurface");
+        return;
+    }
+
+    jclass surface = env->FindClass("android/view/Surface");
+    if (surface == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find android/view/Surface");
+        return;
+    }
+
+    fields.surface_native = env->GetFieldID(surface, "mSurface", "I");
+    if (fields.surface_native == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find Surface.mSurface");
+        return;
+    }
+}
 
 static void
 android_media_MediaPlayer_native_setup(JNIEnv *env, jobject thiz, jobject weak_this)
@@ -576,53 +621,16 @@ static JNINativeMethod gMethods[] = {
     {"native_invoke",       "(Landroid/os/Parcel;Landroid/os/Parcel;)I",(void *)android_media_MediaPlayer_invoke},
     {"native_setMetadataFilter", "(Landroid/os/Parcel;)I",      (void *)android_media_MediaPlayer_setMetadataFilter},
     {"native_getMetadata", "(ZZLandroid/os/Parcel;)Z",          (void *)android_media_MediaPlayer_getMetadata},
+    {"native_init",         "()V",                              (void *)android_media_MediaPlayer_native_init},
     {"native_setup",        "(Ljava/lang/Object;)V",            (void *)android_media_MediaPlayer_native_setup},
     {"native_finalize",     "()V",                              (void *)android_media_MediaPlayer_native_finalize},
 };
 
 static const char* const kClassPathName = "android/media/MediaPlayer";
 
+// This function only registers the native methods
 static int register_android_media_MediaPlayer(JNIEnv *env)
 {
-    jclass clazz;
-
-    clazz = env->FindClass("android/media/MediaPlayer");
-    if (clazz == NULL) {
-        LOGE("Can't find android/media/MediaPlayer");
-        return -1;
-    }
-
-    fields.context = env->GetFieldID(clazz, "mNativeContext", "I");
-    if (fields.context == NULL) {
-        LOGE("Can't find MediaPlayer.mNativeContext");
-        return -1;
-    }
-
-    fields.post_event = env->GetStaticMethodID(clazz, "postEventFromNative",
-                                               "(Ljava/lang/Object;IIILjava/lang/Object;)V");
-    if (fields.post_event == NULL) {
-        LOGE("Can't find MediaPlayer.postEventFromNative");
-        return -1;
-    }
-
-    fields.surface = env->GetFieldID(clazz, "mSurface", "Landroid/view/Surface;");
-    if (fields.surface == NULL) {
-        LOGE("Can't find MediaPlayer.mSurface");
-        return -1;
-    }
-
-    jclass surface = env->FindClass("android/view/Surface");
-    if (surface == NULL) {
-        LOGE("Can't find android/view/Surface");
-        return -1;
-    }
-
-    fields.surface_native = env->GetFieldID(surface, "mSurface", "I");
-    if (fields.surface_native == NULL) {
-        LOGE("Can't find Surface fields");
-        return -1;
-    }
-
     return AndroidRuntime::registerNativeMethods(env,
                 "android/media/MediaPlayer", gMethods, NELEM(gMethods));
 }
diff --git a/media/jni/android_media_MediaRecorder.cpp b/media/jni/android_media_MediaRecorder.cpp
index 304f521..cad65b3 100644
--- a/media/jni/android_media_MediaRecorder.cpp
+++ b/media/jni/android_media_MediaRecorder.cpp
@@ -371,6 +371,53 @@ android_media_MediaRecorder_release(JNIEnv *env, jobject thiz)
     }
 }
 
+// This function gets some field IDs, which in turn causes class initialization.
+// It is called from a static block in MediaRecorder, which won't run until the
+// first time an instance of this class is used.
+static void
+android_media_MediaRecorder_native_init(JNIEnv *env)
+{
+    jclass clazz;
+
+    clazz = env->FindClass("android/media/MediaRecorder");
+    if (clazz == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find android/media/MediaRecorder");
+        return;
+    }
+
+    fields.context = env->GetFieldID(clazz, "mNativeContext", "I");
+    if (fields.context == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find MediaRecorder.mNativeContext");
+        return;
+    }
+
+    fields.surface = env->GetFieldID(clazz, "mSurface", "Landroid/view/Surface;");
+    if (fields.surface == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find MediaRecorder.mSurface");
+        return;
+    }
+
+    jclass surface = env->FindClass("android/view/Surface");
+    if (surface == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find android/view/Surface");
+        return;
+    }
+
+    fields.surface_native = env->GetFieldID(surface, "mSurface", "I");
+    if (fields.surface_native == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find Surface.mSurface");
+        return;
+    }
+
+    fields.post_event = env->GetStaticMethodID(clazz, "postEventFromNative",
+                                               "(Ljava/lang/Object;IIILjava/lang/Object;)V");
+    if (fields.post_event == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "MediaRecorder.postEventFromNative");
+        return;
+    }
+}
+
+
 static void
 android_media_MediaRecorder_native_setup(JNIEnv *env, jobject thiz, jobject weak_this)
 {
@@ -418,55 +465,19 @@ static JNINativeMethod gMethods[] = {
     {"getMaxAmplitude",      "()I",                             (void *)android_media_MediaRecorder_native_getMaxAmplitude},
     {"start",                "()V",                             (void *)android_media_MediaRecorder_start},
     {"stop",                 "()V",                             (void *)android_media_MediaRecorder_stop},
-    {"native_reset",                "()V",                             (void *)android_media_MediaRecorder_native_reset},
+    {"native_reset",         "()V",                             (void *)android_media_MediaRecorder_native_reset},
     {"release",              "()V",                             (void *)android_media_MediaRecorder_release},
+    {"native_init",          "()V",                             (void *)android_media_MediaRecorder_native_init},
     {"native_setup",         "(Ljava/lang/Object;)V",           (void *)android_media_MediaRecorder_native_setup},
     {"native_finalize",      "()V",                             (void *)android_media_MediaRecorder_native_finalize},
 };
 
 static const char* const kClassPathName = "android/media/MediaRecorder";
 
+// This function only registers the native methods, and is called from
+// JNI_OnLoad in android_media_MediaPlayer.cpp
 int register_android_media_MediaRecorder(JNIEnv *env)
 {
-    jclass clazz;
-
-    clazz = env->FindClass("android/media/MediaRecorder");
-    if (clazz == NULL) {
-        LOGE("Can't find android/media/MediaRecorder");
-        return -1;
-    }
-
-    fields.context = env->GetFieldID(clazz, "mNativeContext", "I");
-    if (fields.context == NULL) {
-        LOGE("Can't find MediaRecorder.mNativeContext");
-        return -1;
-    }
-
-    fields.surface = env->GetFieldID(clazz, "mSurface", "Landroid/view/Surface;");
-    if (fields.surface == NULL) {
-        LOGE("Can't find MediaRecorder.mSurface");
-        return -1;
-    }
-
-    jclass surface = env->FindClass("android/view/Surface");
-    if (surface == NULL) {
-        LOGE("Can't find android/view/Surface");
-        return -1;
-    }
-
-    fields.surface_native = env->GetFieldID(surface, "mSurface", "I");
-    if (fields.surface_native == NULL) {
-        LOGE("Can't find Surface fields");
-        return -1;
-    }
-
-    fields.post_event = env->GetStaticMethodID(clazz, "postEventFromNative",
-                                               "(Ljava/lang/Object;IIILjava/lang/Object;)V");
-    if (fields.post_event == NULL) {
-        LOGE("Can't find MediaRecorder.postEventFromNative");
-        return -1;
-    }
-
     return AndroidRuntime::registerNativeMethods(env,
                 "android/media/MediaRecorder", gMethods, NELEM(gMethods));
 }
diff --git a/media/jni/android_media_MediaScanner.cpp b/media/jni/android_media_MediaScanner.cpp
index 8764a70..97de486 100644
--- a/media/jni/android_media_MediaScanner.cpp
+++ b/media/jni/android_media_MediaScanner.cpp
@@ -241,6 +241,27 @@ done:
     return array;
 }
 
+// This function gets a field ID, which in turn causes class initialization.
+// It is called from a static block in MediaScanner, which won't run until the
+// first time an instance of this class is used.
+static void
+android_media_MediaScanner_native_init(JNIEnv *env)
+{
+     jclass clazz;
+
+    clazz = env->FindClass("android/media/MediaScanner");
+    if (clazz == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find android/media/MediaScanner");
+        return;
+    }
+
+    fields.context = env->GetFieldID(clazz, "mNativeContext", "I");
+    if (fields.context == NULL) {
+        jniThrowException(env, "java/lang/RuntimeException", "Can't find MediaScanner.mNativeContext");
+        return;
+    }
+}
+
 static void
 android_media_MediaScanner_native_setup(JNIEnv *env, jobject thiz)
 {
@@ -275,28 +296,17 @@ static JNINativeMethod gMethods[] = {
                                                         (void *)android_media_MediaScanner_processFile},
     {"setLocale",         "(Ljava/lang/String;)V",      (void *)android_media_MediaScanner_setLocale},
     {"extractAlbumArt",   "(Ljava/io/FileDescriptor;)[B",     (void *)android_media_MediaScanner_extractAlbumArt},
+    {"native_init",        "()V",                      (void *)android_media_MediaScanner_native_init},
     {"native_setup",        "()V",                      (void *)android_media_MediaScanner_native_setup},
     {"native_finalize",     "()V",                      (void *)android_media_MediaScanner_native_finalize},
 };
 
 static const char* const kClassPathName = "android/media/MediaScanner";
 
+// This function only registers the native methods, and is called from
+// JNI_OnLoad in android_media_MediaPlayer.cpp
 int register_android_media_MediaScanner(JNIEnv *env)
 {
-    jclass clazz;
-
-    clazz = env->FindClass("android/media/MediaScanner");
-    if (clazz == NULL) {
-        LOGE("Can't find android/media/MediaScanner");
-        return -1;
-    }
-
-    fields.context = env->GetFieldID(clazz, "mNativeContext", "I");
-    if (fields.context == NULL) {
-        LOGE("Can't find MediaScanner.mNativeContext");
-        return -1;
-    }
-
     return AndroidRuntime::registerNativeMethods(env,
                 "android/media/MediaScanner", gMethods, NELEM(gMethods));
 }
diff --git a/media/jni/android_media_ResampleInputStream.cpp b/media/jni/android_media_ResampleInputStream.cpp
index 0247cdb..f248557 100644
--- a/media/jni/android_media_ResampleInputStream.cpp
+++ b/media/jni/android_media_ResampleInputStream.cpp
@@ -128,13 +128,6 @@ static JNINativeMethod gMethods[] = {
 int register_android_media_ResampleInputStream(JNIEnv *env)
 {
     const char* const kClassPathName = "android/media/ResampleInputStream";
-    jclass clazz;
-
-    clazz = env->FindClass(kClassPathName);
-    if (clazz == NULL) {
-        LOGE("Can't find %s", kClassPathName);
-        return -1;
-    }
 
     return AndroidRuntime::registerNativeMethods(env,
             kClassPathName, gMethods, NELEM(gMethods));