MTP host: Add support for reading files from an MTP device via ParcelFileDescriptor

Also added some support for sending files to the device that hasn't been debugged yet.
Add locking to MtpDevice to prevent it from attempting multiple transactions simultaneously.

Change-Id: I2b995ba0af086cc6920bd6b8c869f540ad78560a
Signed-off-by: Mike Lockwood <lockwood@android.com>

1 files changed, 14 insertions, 1 deletions

diff --git a/media/mtp/MtpDevice.h b/media/mtp/MtpDevice.h
index e41a872..57f492f 100644
--- a/media/mtp/MtpDevice.h
+++ b/media/mtp/MtpDevice.h
@@ -22,6 +22,8 @@
 #include "MtpResponsePacket.h"
 #include "MtpTypes.h"
 
+#include <utils/threads.h>
+
 struct usb_device;
 
 namespace android {
@@ -52,6 +54,9 @@ private:
     MtpDataPacket           mData;
     MtpResponsePacket       mResponse;
 
+    // to ensure only one MTP transaction at a time
+    Mutex                   mMutex;
+
 public:
                             MtpDevice(struct usb_device* device, int interface,
                                     struct usb_endpoint *ep_in, struct usb_endpoint *ep_out,
@@ -73,16 +78,24 @@ public:
     MtpObjectHandleList*    getObjectHandles(MtpStorageID storageID, MtpObjectFormat format, MtpObjectHandle parent);
     MtpObjectInfo*          getObjectInfo(MtpObjectHandle handle);
     void*                   getThumbnail(MtpObjectHandle handle, int& outLength);
+    MtpObjectHandle         sendObjectInfo(MtpObjectInfo* info);
+    bool                    sendObject(MtpObjectInfo* info, int srcFD);
     bool                    deleteObject(MtpObjectHandle handle);
     MtpObjectHandle         getParent(MtpObjectHandle handle);
     MtpObjectHandle         getStorageID(MtpObjectHandle handle);
 
     MtpProperty*            getDevicePropDesc(MtpDeviceProperty code);
 
+    // returns the file descriptor for a pipe to read the object's data
+    int                     readObject(MtpObjectHandle handle, int objectSize);
+
 private:
+    friend class ReadObjectThread;
+
     bool                    sendRequest(MtpOperationCode operation);
-    bool                    sendData(MtpOperationCode operation);
+    bool                    sendData();
     bool                    readData();
+    bool                    writeDataHeader(MtpOperationCode operation, int dataLength);
     MtpResponseCode         readResponse();
 
 };