PTP: Improve performance and reliability of file importing

Now the file copy is done completely within the media process
rather than pushing data to the client via ContProvider.openFile().

File system writes are now interleaved with USB reads, which allows us
to copy the data faster and prevents the camera from timing out during transfer.

File is automatically inserted in the media provider after a successful import
and a Uri is returned to the client.

BUG: 2994234

Change-Id: Ie75c63da76f623343d3d966c6a707aa1ae871972
Signed-off-by: Mike Lockwood <lockwood@android.com>

1 files changed, 10 insertions, 53 deletions

diff --git a/media/jni/android_media_MtpClient.cpp b/media/jni/android_media_MtpClient.cpp
index d23185b..6235fc0 100644
--- a/media/jni/android_media_MtpClient.cpp
+++ b/media/jni/android_media_MtpClient.cpp
@@ -39,19 +39,6 @@ static jmethodID method_deviceAdded;
 static jmethodID method_deviceRemoved;
 static jfieldID field_context;
 
-static struct file_descriptor_offsets_t
-{
-    jclass mClass;
-    jmethodID mConstructor;
-    jfieldID mDescriptor;
-} gFileDescriptorOffsets;
-
-static struct parcel_file_descriptor_offsets_t
-{
-    jclass mClass;
-    jmethodID mConstructor;
-} gParcelFileDescriptorOffsets;
-
 #ifdef HAVE_ANDROID_OS
 
 static void checkAndClearExceptionFromCallback(JNIEnv* env, const char* methodName) {
@@ -201,34 +188,19 @@ android_media_MtpClient_get_storage_id(JNIEnv *env, jobject thiz,
         return -1;
 }
 
-static jobject
-android_media_MtpClient_open_file(JNIEnv *env, jobject thiz,
-        jint device_id, jlong object_id)
+static jboolean
+android_media_MtpClient_import_file(JNIEnv *env, jobject thiz,
+        jint device_id, jlong object_id, jstring dest_path)
 {
 #ifdef HAVE_ANDROID_OS
     MyClient *client = (MyClient *)env->GetIntField(thiz, field_context);
     MtpDevice* device = client->getDevice(device_id);
-    if (!device)
-        return NULL;
-
-    MtpObjectInfo* info = device->getObjectInfo(object_id);
-    if (!info)
-        return NULL;
-    int object_size = info->mCompressedSize;
-    delete info;
-    int fd = device->readObject(object_id, object_size);
-    if (fd < 0)
-        return NULL;
-
-    jobject fileDescriptor = env->NewObject(gFileDescriptorOffsets.mClass,
-        gFileDescriptorOffsets.mConstructor);
-    if (fileDescriptor != NULL) {
-        env->SetIntField(fileDescriptor, gFileDescriptorOffsets.mDescriptor, fd);
-    } else {
-        return NULL;
+    if (device) {
+        const char *destPathStr = env->GetStringUTFChars(dest_path, NULL);
+        bool result = device->readObject(object_id, destPathStr);
+        env->ReleaseStringUTFChars(dest_path, destPathStr);
+        return result;
     }
-    return env->NewObject(gParcelFileDescriptorOffsets.mClass,
-        gParcelFileDescriptorOffsets.mConstructor, fileDescriptor);
 #endif
     return NULL;
 }
@@ -243,8 +215,8 @@ static JNINativeMethod gMethods[] = {
     {"native_delete_object",   "(IJ)Z", (void *)android_media_MtpClient_delete_object},
     {"native_get_parent",      "(IJ)J", (void *)android_media_MtpClient_get_parent},
     {"native_get_storage_id",  "(IJ)J", (void *)android_media_MtpClient_get_storage_id},
-    {"native_open_file",       "(IJ)Landroid/os/ParcelFileDescriptor;",
-                                        (void *)android_media_MtpClient_open_file},
+    {"native_import_file",     "(IJLjava/lang/String;)Z",
+                                        (void *)android_media_MtpClient_import_file},
 };
 
 static const char* const kClassPathName = "android/media/MtpClient";
@@ -276,21 +248,6 @@ int register_android_media_MtpClient(JNIEnv *env)
         return -1;
     }
 
-   clazz = env->FindClass("java/io/FileDescriptor");
-    LOG_FATAL_IF(clazz == NULL, "Unable to find class java.io.FileDescriptor");
-    gFileDescriptorOffsets.mClass = (jclass) env->NewGlobalRef(clazz);
-    gFileDescriptorOffsets.mConstructor = env->GetMethodID(clazz, "<init>", "()V");
-    gFileDescriptorOffsets.mDescriptor = env->GetFieldID(clazz, "descriptor", "I");
-    LOG_FATAL_IF(gFileDescriptorOffsets.mDescriptor == NULL,
-                 "Unable to find descriptor field in java.io.FileDescriptor");
-
-   clazz = env->FindClass("android/os/ParcelFileDescriptor");
-    LOG_FATAL_IF(clazz == NULL, "Unable to find class android.os.ParcelFileDescriptor");
-    gParcelFileDescriptorOffsets.mClass = (jclass) env->NewGlobalRef(clazz);
-    gParcelFileDescriptorOffsets.mConstructor = env->GetMethodID(clazz, "<init>", "(Ljava/io/FileDescriptor;)V");
-    LOG_FATAL_IF(gParcelFileDescriptorOffsets.mConstructor == NULL,
-                 "Unable to find constructor for android.os.ParcelFileDescriptor");
-
     return AndroidRuntime::registerNativeMethods(env,
                 "android/media/MtpClient", gMethods, NELEM(gMethods));
 }