mtp/ffs/MtpDevice.h

/*
 * Copyright (C) 2010 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 _MTP_DEVICE_H
#define _MTP_DEVICE_H

#include "MtpEventPacket.h"
#include "MtpDataPacket.h"
#include "MtpRequestPacket.h"
#include "MtpResponsePacket.h"
#include "MtpTypes.h"

#include <mutex>

struct usb_device;
struct usb_request;
struct usb_endpoint_descriptor;

class MtpDeviceInfo;
class MtpEventPacket;
class MtpObjectInfo;
class MtpStorageInfo;

class MtpDevice {
private:
	struct usb_device*		mDevice;
	int						mInterface;
	struct usb_request*		mRequestIn1;
	struct usb_request*		mRequestIn2;
	struct usb_request*		mRequestOut;
	struct usb_request*		mRequestIntr;
	MtpDeviceInfo*			mDeviceInfo;
	MtpPropertyList			mDeviceProperties;

	// current session ID
	MtpSessionID			mSessionID;
	// current transaction ID
	MtpTransactionID		mTransactionID;

	MtpRequestPacket		mRequest;
	MtpDataPacket			mData;
	MtpResponsePacket		mResponse;
	MtpEventPacket			mEventPacket;

	// set to true if we received a response packet instead of a data packet
	bool					mReceivedResponse;
	bool					mProcessingEvent;
	int						mCurrentEventHandle;

	// to check if a sendObject request follows the last sendObjectInfo request.
	MtpTransactionID		mLastSendObjectInfoTransactionID;
	MtpObjectHandle			mLastSendObjectInfoObjectHandle;

	// to ensure only one MTP transaction at a time
	std::mutex				mMutex;
	std::mutex				mEventMutex;
	std::mutex				mEventMutexForInterrupt;

	// Remember the device's packet division mode.
	UrbPacketDivisionMode	mPacketDivisionMode;

public:
	typedef bool (*ReadObjectCallback)
			(void* data, uint32_t offset, uint32_t length, void* clientData);

	MtpDevice(struct usb_device* device,
			  int interface,
			  const struct usb_endpoint_descriptor *ep_in,
			  const struct usb_endpoint_descriptor *ep_out,
			  const struct usb_endpoint_descriptor *ep_intr);

	static MtpDevice*		open(const char* deviceName, int fd);

	virtual					~MtpDevice();

	void					initialize();
	void					close();
	void					print();
	const char*				getDeviceName();

	bool					openSession();
	bool					closeSession();

	MtpDeviceInfo*			getDeviceInfo();
	MtpStorageIDList*		getStorageIDs();
	MtpStorageInfo*			getStorageInfo(MtpStorageID storageID);
	MtpObjectHandleList*	getObjectHandles(MtpStorageID storageID, MtpObjectFormat format,
									MtpObjectHandle parent);
	MtpObjectInfo*			getObjectInfo(MtpObjectHandle handle);
	void*					getThumbnail(MtpObjectHandle handle, int& outLength);
	MtpObjectHandle			sendObjectInfo(MtpObjectInfo* info);
	bool					sendObject(MtpObjectHandle handle, int size, int srcFD);
	bool					deleteObject(MtpObjectHandle handle);
	MtpObjectHandle			getParent(MtpObjectHandle handle);
	MtpStorageID			getStorageID(MtpObjectHandle handle);

	MtpObjectPropertyList*	getObjectPropsSupported(MtpObjectFormat format);

	MtpProperty*			getDevicePropDesc(MtpDeviceProperty code);
	MtpProperty*			getObjectPropDesc(MtpObjectProperty code, MtpObjectFormat format);

	// Reads value of |property| for |handle|. Returns true on success.
	bool					getObjectPropValue(MtpObjectHandle handle, MtpProperty* property);

	bool					readObject(MtpObjectHandle handle, ReadObjectCallback callback,
									uint32_t objectSize, void* clientData);
	bool					readObject(MtpObjectHandle handle, const char* destPath, int group,
									int perm);
	bool					readObject(MtpObjectHandle handle, int fd);
	bool					readPartialObject(MtpObjectHandle handle,
											  uint32_t offset,
											  uint32_t size,
											  uint32_t *writtenSize,
											  ReadObjectCallback callback,
											  void* clientData);
	bool					readPartialObject64(MtpObjectHandle handle,
												uint64_t offset,
												uint32_t size,
												uint32_t *writtenSize,
												ReadObjectCallback callback,
												void* clientData);
	// Starts a request to read MTP event from MTP device. It returns a request handle that
	// can be used for blocking read or cancel. If other thread has already been processing an
	// event returns -1.
	int						submitEventRequest();
	// Waits for MTP event from the device and returns MTP event code. It blocks the current thread
	// until it receives an event from the device. |handle| should be a request handle returned
	// by |submitEventRequest|. The function writes event parameters to |parameters|. Returns 0 for
	// cancellations. Returns -1 for errors.
	int						reapEventRequest(int handle, uint32_t (*parameters)[3]);
	// Cancels an event request. |handle| should be request handle returned by
	// |submitEventRequest|. If there is a thread blocked by |reapEventRequest| with the same
	// |handle|, the thread will resume.
	void					discardEventRequest(int handle);

private:
	// If |objectSize| is not NULL, it checks object size before reading data bytes.
	bool					readObjectInternal(MtpObjectHandle handle,
											   ReadObjectCallback callback,
											   const uint32_t* objectSize,
											   void* clientData);
	// If |objectSize| is not NULL, it checks object size before reading data bytes.
	bool					readData(ReadObjectCallback callback,
									 const uint32_t* objectSize,
									 uint32_t* writtenData,
									 void* clientData);
	bool					sendRequest(MtpOperationCode operation);
	bool					sendData();
	bool					readData();
	bool					writeDataHeader(MtpOperationCode operation, int dataLength);
	MtpResponseCode			readResponse();
};

#endif // _MTP_DEVICE_H