Unhide the android.media.[Media]DataSource interface.

This allows apps to implement MediaDataSource, which is modeled on
stagefright's DataSource, to supply media data to the framework. This
was already implemented for MediaExtractor, but it was renamed from
DataSource.

MediaExtractor, MediaPlayer and MediaMetadataRetriever each have a new
overload: #setDataSource(android.media.MediaDataSource)

Only NuPlayer supports this new data source.

The change introduces:
 * IDataSource:        The binder interface for DataSource.
 * JMediaDataSource:   The native counterpart to the java interface. It
                       implements IDataSource.
 * CallbackDataSource: A stagefright DataSource that wraps an IDataSource.

Change-Id: I6d9c1167b4a7384c469b1e928f31791a7ebed716

7 files changed, 265 insertions, 72 deletions

diff --git a/media/jni/Android.mk b/media/jni/Android.mk
index 5b177e5..8cf9874 100644
--- a/media/jni/Android.mk
+++ b/media/jni/Android.mk
@@ -7,6 +7,7 @@ LOCAL_SRC_FILES:= \
     android_media_MediaCrypto.cpp \
     android_media_MediaCodec.cpp \
     android_media_MediaCodecList.cpp \
+    android_media_MediaDataSource.cpp \
     android_media_MediaDrm.cpp \
     android_media_MediaExtractor.cpp \
     android_media_MediaHTTPConnection.cpp \
diff --git a/media/jni/android_media_MediaDataSource.cpp b/media/jni/android_media_MediaDataSource.cpp
new file mode 100644
index 0000000..1e6d2af
--- /dev/null
+++ b/media/jni/android_media_MediaDataSource.cpp
@@ -0,0 +1,148 @@
+/*
+ * Copyright 2015, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//#define LOG_NDEBUG 0
+#define LOG_TAG "JMediaDataSource-JNI"
+#include <utils/Log.h>
+
+#include "android_media_MediaDataSource.h"
+
+#include "android_runtime/AndroidRuntime.h"
+#include "android_runtime/Log.h"
+#include "jni.h"
+#include "JNIHelp.h"
+
+#include <binder/MemoryDealer.h>
+#include <media/stagefright/foundation/ADebug.h>
+#include <nativehelper/ScopedLocalRef.h>
+
+namespace android {
+
+JMediaDataSource::JMediaDataSource(JNIEnv* env, jobject source)
+    : mJavaObjStatus(OK), mSizeIsCached(false), mCachedSize(0), mMemory(NULL) {
+    mMediaDataSourceObj = env->NewGlobalRef(source);
+    CHECK(mMediaDataSourceObj != NULL);
+
+    ScopedLocalRef<jclass> mediaDataSourceClass(env, env->GetObjectClass(mMediaDataSourceObj));
+    CHECK(mediaDataSourceClass.get() != NULL);
+
+    mReadMethod = env->GetMethodID(mediaDataSourceClass.get(), "readAt", "(J[BI)I");
+    CHECK(mReadMethod != NULL);
+    mGetSizeMethod = env->GetMethodID(mediaDataSourceClass.get(), "getSize", "()J");
+    CHECK(mGetSizeMethod != NULL);
+    mCloseMethod = env->GetMethodID(mediaDataSourceClass.get(), "close", "()V");
+    CHECK(mCloseMethod != NULL);
+
+    ScopedLocalRef<jbyteArray> tmp(env, env->NewByteArray(kBufferSize));
+    mByteArrayObj = (jbyteArray)env->NewGlobalRef(tmp.get());
+    CHECK(mByteArrayObj != NULL);
+
+    sp<MemoryDealer> memoryDealer = new MemoryDealer(kBufferSize, "JMediaDataSource");
+    mMemory = memoryDealer->allocate(kBufferSize);
+    if (mMemory == NULL) {
+        ALOGE("Failed to allocate memory!");
+    }
+}
+
+JMediaDataSource::~JMediaDataSource() {
+    JNIEnv* env = AndroidRuntime::getJNIEnv();
+    env->DeleteGlobalRef(mMediaDataSourceObj);
+    env->DeleteGlobalRef(mByteArrayObj);
+}
+
+sp<IMemory> JMediaDataSource::getIMemory() {
+    Mutex::Autolock lock(mLock);
+    return mMemory;
+}
+
+ssize_t JMediaDataSource::readAt(off64_t offset, size_t size) {
+    Mutex::Autolock lock(mLock);
+
+    if (mJavaObjStatus != OK || mMemory == NULL) {
+        return -1;
+    }
+    if (size > kBufferSize) {
+        size = kBufferSize;
+    }
+
+    JNIEnv* env = AndroidRuntime::getJNIEnv();
+    jint numread = env->CallIntMethod(mMediaDataSourceObj, mReadMethod,
+                                      (jlong)offset, mByteArrayObj, (jint)size);
+    if (env->ExceptionCheck()) {
+        ALOGW("An exception occurred in readAt()");
+        LOGW_EX(env);
+        env->ExceptionClear();
+        mJavaObjStatus = UNKNOWN_ERROR;
+        return -1;
+    }
+    if (numread < 0) {
+        ALOGW("An error occurred in readAt()");
+        mJavaObjStatus = UNKNOWN_ERROR;
+        return -1;
+    }
+    if ((size_t)numread > size) {
+        ALOGE("readAt read too many bytes.");
+        mJavaObjStatus = UNKNOWN_ERROR;
+        return -1;
+    }
+
+    ALOGV("readAt %lld / %zu => %d.", (long long)offset, size, numread);
+    env->GetByteArrayRegion(mByteArrayObj, 0, numread, (jbyte*)mMemory->pointer());
+    return numread;
+}
+
+status_t JMediaDataSource::getSize(off64_t* size) {
+    Mutex::Autolock lock(mLock);
+
+    if (mJavaObjStatus != OK) {
+        return UNKNOWN_ERROR;
+    }
+    if (mSizeIsCached) {
+        return mCachedSize;
+    }
+
+    JNIEnv* env = AndroidRuntime::getJNIEnv();
+    *size = env->CallLongMethod(mMediaDataSourceObj, mGetSizeMethod);
+    if (env->ExceptionCheck()) {
+        ALOGW("An exception occurred in getSize()");
+        LOGW_EX(env);
+        env->ExceptionClear();
+        // After returning an error, size shouldn't be used by callers.
+        *size = UNKNOWN_ERROR;
+        mJavaObjStatus = UNKNOWN_ERROR;
+        return UNKNOWN_ERROR;
+    }
+
+    // The minimum size should be -1, which indicates unknown size.
+    if (*size < 0) {
+        *size = -1;
+    }
+
+    mCachedSize = *size;
+    mSizeIsCached = true;
+    return OK;
+}
+
+void JMediaDataSource::close() {
+    Mutex::Autolock lock(mLock);
+
+    JNIEnv* env = AndroidRuntime::getJNIEnv();
+    env->CallVoidMethod(mMediaDataSourceObj, mCloseMethod);
+    // The closed state is effectively the same as an error state.
+    mJavaObjStatus = UNKNOWN_ERROR;
+}
+
+}  // namespace android
diff --git a/media/jni/android_media_MediaDataSource.h b/media/jni/android_media_MediaDataSource.h
new file mode 100644
index 0000000..2bc237e
--- /dev/null
+++ b/media/jni/android_media_MediaDataSource.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2015, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _ANDROID_MEDIA_MEDIADATASOURCE_H_
+#define _ANDROID_MEDIA_MEDIADATASOURCE_H_
+
+#include "jni.h"
+
+#include <media/IDataSource.h>
+#include <media/stagefright/foundation/ABase.h>
+#include <utils/Errors.h>
+#include <utils/Mutex.h>
+
+namespace android {
+
+// The native counterpart to a Java android.media.MediaDataSource. It inherits from
+// IDataSource so that it can be accessed remotely.
+//
+// If the java DataSource returns an error or throws an exception it
+// will be considered to be in a broken state, and the only further call this
+// will make is to close().
+class JMediaDataSource : public BnDataSource {
+public:
+    enum {
+        kBufferSize = 64 * 1024,
+    };
+
+    JMediaDataSource(JNIEnv *env, jobject source);
+    virtual ~JMediaDataSource();
+
+    virtual sp<IMemory> getIMemory();
+    virtual ssize_t readAt(off64_t offset, size_t size);
+    virtual status_t getSize(off64_t* size);
+    virtual void close();
+
+private:
+    // Protect all member variables with mLock because this object will be
+    // accessed on different binder worker threads.
+    Mutex mLock;
+
+    // The status of the java DataSource. Set to OK unless an error occurred or
+    // close() was called.
+    status_t mJavaObjStatus;
+    // Only call the java getSize() once so the app can't change the size on us.
+    bool mSizeIsCached;
+    off64_t mCachedSize;
+    sp<IMemory> mMemory;
+
+    jobject mMediaDataSourceObj;
+    jmethodID mReadMethod;
+    jmethodID mGetSizeMethod;
+    jmethodID mCloseMethod;
+    jbyteArray mByteArrayObj;
+
+    DISALLOW_EVIL_CONSTRUCTORS(JMediaDataSource);
+};
+
+}  // namespace android
+
+#endif  // _ANDROID_MEDIA_MEDIADATASOURCE_H_
diff --git a/media/jni/android_media_MediaExtractor.cpp b/media/jni/android_media_MediaExtractor.cpp
index c0795b6..b6b7a80 100644
--- a/media/jni/android_media_MediaExtractor.cpp
+++ b/media/jni/android_media_MediaExtractor.cpp
@@ -25,6 +25,7 @@
 #include "android_runtime/Log.h"
 #include "jni.h"
 #include "JNIHelp.h"
+#include "android_media_MediaDataSource.h"
 
 #include <media/IMediaHTTPService.h>
 #include <media/hardware/CryptoAPI.h>
@@ -50,74 +51,6 @@ struct fields_t {
 
 static fields_t gFields;
 
-class JavaDataSourceBridge : public DataSource {
-    jmethodID mReadMethod;
-    jmethodID mGetSizeMethod;
-    jmethodID mCloseMethod;
-    jobject   mDataSource;
- public:
-    JavaDataSourceBridge(JNIEnv *env, jobject source) {
-        mDataSource = env->NewGlobalRef(source);
-
-        jclass datasourceclass = env->GetObjectClass(mDataSource);
-        CHECK(datasourceclass != NULL);
-
-        mReadMethod = env->GetMethodID(datasourceclass, "readAt", "(J[BI)I");
-        CHECK(mReadMethod != NULL);
-
-        mGetSizeMethod = env->GetMethodID(datasourceclass, "getSize", "()J");
-        CHECK(mGetSizeMethod != NULL);
-
-        mCloseMethod = env->GetMethodID(datasourceclass, "close", "()V");
-        CHECK(mCloseMethod != NULL);
-    }
-
-    ~JavaDataSourceBridge() {
-        JNIEnv *env = AndroidRuntime::getJNIEnv();
-        env->CallVoidMethod(mDataSource, mCloseMethod);
-        env->DeleteGlobalRef(mDataSource);
-    }
-
-    virtual status_t initCheck() const {
-        return OK;
-    }
-
-    virtual ssize_t readAt(off64_t offset, void* buffer, size_t size) {
-        JNIEnv *env = AndroidRuntime::getJNIEnv();
-
-        // XXX could optimize this by reusing the same array
-        jbyteArray byteArrayObj = env->NewByteArray(size);
-        env->DeleteLocalRef(env->GetObjectClass(mDataSource));
-        env->DeleteLocalRef(env->GetObjectClass(byteArrayObj));
-        ssize_t numread = env->CallIntMethod(mDataSource, mReadMethod, offset, byteArrayObj, (jint)size);
-        env->GetByteArrayRegion(byteArrayObj, 0, size, (jbyte*) buffer);
-        env->DeleteLocalRef(byteArrayObj);
-        if (env->ExceptionCheck()) {
-            ALOGW("Exception occurred while reading %zu at %lld", size, (long long)offset);
-            LOGW_EX(env);
-            env->ExceptionClear();
-            return -1;
-        }
-        return numread;
-    }
-
-    virtual status_t getSize(off64_t *size) {
-        JNIEnv *env = AndroidRuntime::getJNIEnv();
-
-        CHECK(size != NULL);
-
-        int64_t len = env->CallLongMethod(mDataSource, mGetSizeMethod);
-        if (len < 0) {
-            *size = ERROR_UNSUPPORTED;
-        } else {
-            *size = len;
-        }
-        return OK;
-    }
-};
-
-////////////////////////////////////////////////////////////////////////////////
-
 JMediaExtractor::JMediaExtractor(JNIEnv *env, jobject thiz)
     : mClass(NULL),
       mObject(NULL) {
@@ -777,7 +710,8 @@ static void android_media_MediaExtractor_setDataSourceCallback(
         return;
     }
 
-    sp<JavaDataSourceBridge> bridge = new JavaDataSourceBridge(env, callbackObj);
+    sp<DataSource> bridge =
+        DataSource::CreateFromIDataSource(new JMediaDataSource(env, callbackObj));
     status_t err = extractor->setDataSource(bridge);
 
     if (err != OK) {
@@ -881,7 +815,7 @@ static JNINativeMethod gMethods[] = {
     { "setDataSource", "(Ljava/io/FileDescriptor;JJ)V",
       (void *)android_media_MediaExtractor_setDataSourceFd },
 
-    { "setDataSource", "(Landroid/media/DataSource;)V",
+    { "setDataSource", "(Landroid/media/MediaDataSource;)V",
       (void *)android_media_MediaExtractor_setDataSourceCallback },
 
     { "getCachedDuration", "()J",
diff --git a/media/jni/android_media_MediaHTTPConnection.cpp b/media/jni/android_media_MediaHTTPConnection.cpp
index 7226ef5..393003d 100644
--- a/media/jni/android_media_MediaHTTPConnection.cpp
+++ b/media/jni/android_media_MediaHTTPConnection.cpp
@@ -134,7 +134,6 @@ static jobject android_media_MediaHTTPConnection_native_getIMemory(
 static jint android_media_MediaHTTPConnection_native_readAt(
         JNIEnv *env, jobject thiz, jlong offset, jint size) {
     sp<JMediaHTTPConnection> conn = getObject(env, thiz);
-
     if (size > JMediaHTTPConnection::kBufferSize) {
         size = JMediaHTTPConnection::kBufferSize;
     }
diff --git a/media/jni/android_media_MediaMetadataRetriever.cpp b/media/jni/android_media_MediaMetadataRetriever.cpp
index c6fa379..59fb6d6 100644
--- a/media/jni/android_media_MediaMetadataRetriever.cpp
+++ b/media/jni/android_media_MediaMetadataRetriever.cpp
@@ -30,6 +30,7 @@
 #include "jni.h"
 #include "JNIHelp.h"
 #include "android_runtime/AndroidRuntime.h"
+#include "android_media_MediaDataSource.h"
 #include "android_media_Utils.h"
 #include "android_util_Binder.h"
 
@@ -171,6 +172,23 @@ static void android_media_MediaMetadataRetriever_setDataSourceFD(JNIEnv *env, jo
     process_media_retriever_call(env, retriever->setDataSource(fd, offset, length), "java/lang/RuntimeException", "setDataSource failed");
 }
 
+static void android_media_MediaMetadataRetriever_setDataSourceCallback(JNIEnv *env, jobject thiz, jobject dataSource)
+{
+    ALOGV("setDataSourceCallback");
+    MediaMetadataRetriever* retriever = getRetriever(env, thiz);
+    if (retriever == 0) {
+        jniThrowException(env, "java/lang/IllegalStateException", "No retriever available");
+        return;
+    }
+    if (dataSource == NULL) {
+        jniThrowException(env, "java/lang/IllegalArgumentException", NULL);
+        return;
+    }
+
+    sp<IDataSource> callbackDataSource = new JMediaDataSource(env, dataSource);
+    process_media_retriever_call(env, retriever->setDataSource(callbackDataSource), "java/lang/RuntimeException", "setDataSourceCallback failed");
+}
+
 template<typename T>
 static void rotate0(T* dst, const T* src, size_t width, size_t height)
 {
@@ -457,6 +475,7 @@ static JNINativeMethod nativeMethods[] = {
         },
 
         {"setDataSource",   "(Ljava/io/FileDescriptor;JJ)V", (void *)android_media_MediaMetadataRetriever_setDataSourceFD},
+        {"_setDataSource",   "(Landroid/media/MediaDataSource;)V", (void *)android_media_MediaMetadataRetriever_setDataSourceCallback},
         {"_getFrameAtTime", "(JI)Landroid/graphics/Bitmap;", (void *)android_media_MediaMetadataRetriever_getFrameAtTime},
         {"extractMetadata", "(I)Ljava/lang/String;", (void *)android_media_MediaMetadataRetriever_extractMetadata},
         {"getEmbeddedPicture", "(I)[B", (void *)android_media_MediaMetadataRetriever_getEmbeddedPicture},
diff --git a/media/jni/android_media_MediaPlayer.cpp b/media/jni/android_media_MediaPlayer.cpp
index 3e41716..c247220 100644
--- a/media/jni/android_media_MediaPlayer.cpp
+++ b/media/jni/android_media_MediaPlayer.cpp
@@ -36,6 +36,7 @@
 #include "utils/Errors.h"  // for status_t
 #include "utils/KeyedVector.h"
 #include "utils/String8.h"
+#include "android_media_MediaDataSource.h"
 #include "android_media_Utils.h"
 
 #include "android_os_Parcel.h"
@@ -251,6 +252,23 @@ android_media_MediaPlayer_setDataSourceFD(JNIEnv *env, jobject thiz, jobject fil
     process_media_player_call( env, thiz, mp->setDataSource(fd, offset, length), "java/io/IOException", "setDataSourceFD failed." );
 }
 
+static void
+android_media_MediaPlayer_setDataSourceCallback(JNIEnv *env, jobject thiz, jobject dataSource)
+{
+    sp<MediaPlayer> mp = getMediaPlayer(env, thiz);
+    if (mp == NULL ) {
+        jniThrowException(env, "java/lang/IllegalStateException", NULL);
+        return;
+    }
+
+    if (dataSource == NULL) {
+        jniThrowException(env, "java/lang/IllegalArgumentException", NULL);
+        return;
+    }
+    sp<IDataSource> callbackDataSource = new JMediaDataSource(env, dataSource);
+    process_media_player_call(env, thiz, mp->setDataSource(callbackDataSource), "java/lang/RuntimeException", "setDataSourceCallback failed." );
+}
+
 static sp<IGraphicBufferProducer>
 getVideoSurfaceTexture(JNIEnv* env, jobject thiz) {
     IGraphicBufferProducer * const p = (IGraphicBufferProducer*)env->GetLongField(thiz, fields.surface_texture);
@@ -871,7 +889,8 @@ static JNINativeMethod gMethods[] = {
         (void *)android_media_MediaPlayer_setDataSourceAndHeaders
     },
 
-    {"_setDataSource",       "(Ljava/io/FileDescriptor;JJ)V",    (void *)android_media_MediaPlayer_setDataSourceFD},
+    {"_setDataSource",      "(Ljava/io/FileDescriptor;JJ)V",    (void *)android_media_MediaPlayer_setDataSourceFD},
+    {"_setDataSource",      "(Landroid/media/MediaDataSource;)V",(void *)android_media_MediaPlayer_setDataSourceCallback },
     {"_setVideoSurface",    "(Landroid/view/Surface;)V",        (void *)android_media_MediaPlayer_setVideoSurface},
     {"_prepare",            "()V",                              (void *)android_media_MediaPlayer_prepare},
     {"prepareAsync",        "()V",                              (void *)android_media_MediaPlayer_prepareAsync},