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Commit 4d9da140 authored by Mike Lockwood's avatar Mike Lockwood
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DO NOT MERGE MTP: Add extended operations to support in-place editing of files 



MTP does not support partial writes of files (the entire file must be transferred at once).
This makes it impossible to implement a FUSE file system for MTP
with acceptable performance.
To fix this problem, this change adds extended MTP operations to allow
partial writes to files:

SendPartialObject - allows writing a subset of a file, or appending to the end of a file

TruncateObject - allows changing the size of a file

BeginEditObject - must be called before using SendPartialObject and TruncateObject

EndEditObject - commits changes to a file after it has been edited with SendPartialObject or TruncateObject

We also add GetPartialObject64, which is the same as GetPartialObject
but has a 64 bit offset rather than 32.

Change-Id: Id5365e1c4dc55a2d819c16c9db0a3ac2260f9309
Signed-off-by: default avatarMike Lockwood <lockwood@android.com>
parent 462accab

media/mtp/MtpDatabase.h

+2 −1
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ namespace android { 


class MtpDataPacket;

class MtpProperty;

class MtpObjectInfo;



class MtpDatabase {

public:
@@ -81,7 +82,7 @@ public: 
                                            MtpDataPacket& packet) = 0;



    virtual MtpResponseCode         getObjectInfo(MtpObjectHandle handle,

                                            MtpDataPacket& packet) = 0;

                                            MtpObjectInfo& info) = 0;



    virtual MtpResponseCode         getObjectFilePath(MtpObjectHandle handle,

                                            MtpString& outFilePath,

media/mtp/MtpDebug.cpp

+6 −0
Original line number Diff line number Diff line
@@ -63,6 +63,12 @@ static const CodeEntry sOperationCodes[] = { 
    { "MTP_OPERATION_GET_OBJECT_REFERENCES",        0x9810 },

    { "MTP_OPERATION_SET_OBJECT_REFERENCES",        0x9811 },

    { "MTP_OPERATION_SKIP",                         0x9820 },

    // android extensions

    { "MTP_OPERATION_GET_PARTIAL_OBJECT_64",        0x95C1 },

    { "MTP_OPERATION_SEND_PARTIAL_OBJECT",          0x95C2 },

    { "MTP_OPERATION_TRUNCATE_OBJECT",              0x95C3 },

    { "MTP_OPERATION_BEGIN_EDIT_OBJECT",            0x95C4 },

    { "MTP_OPERATION_END_EDIT_OBJECT",              0x95C5 },

    { 0,                                            0      },

};

media/mtp/MtpServer.cpp

+225 −6
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 


#include "MtpDebug.h"

#include "MtpDatabase.h"

#include "MtpObjectInfo.h"

#include "MtpProperty.h"

#include "MtpServer.h"

#include "MtpStorage.h"
@@ -79,6 +80,12 @@ static const MtpOperationCode kSupportedOperationCodes[] = { 
    MTP_OPERATION_GET_OBJECT_REFERENCES,

    MTP_OPERATION_SET_OBJECT_REFERENCES,

//    MTP_OPERATION_SKIP,

    // Android extension for direct file IO

    MTP_OPERATION_GET_PARTIAL_OBJECT_64,

    MTP_OPERATION_SEND_PARTIAL_OBJECT,

    MTP_OPERATION_TRUNCATE_OBJECT,

    MTP_OPERATION_BEGIN_EDIT_OBJECT,

    MTP_OPERATION_END_EDIT_OBJECT,

};



static const MtpEventCode kSupportedEventCodes[] = {
@@ -218,6 +225,15 @@ void MtpServer::run() { 
        }

    }



    // commit any open edits

    int count = mObjectEditList.size();

    for (int i = 0; i < count; i++) {

        ObjectEdit* edit = mObjectEditList[i];

        commitEdit(edit);

        delete edit;

    }

    mObjectEditList.clear();



    if (mSessionOpen)

        mDatabase->sessionEnded();

}
@@ -252,6 +268,44 @@ void MtpServer::sendEvent(MtpEventCode code, uint32_t param1) { 
    }

}



void MtpServer::addEditObject(MtpObjectHandle handle, MtpString& path,

        uint64_t size, MtpObjectFormat format, int fd) {

    ObjectEdit*  edit = new ObjectEdit;

    edit->handle = handle;

    edit->path = path;

    edit->size = size;

    edit->format = format;

    edit->fd = fd;

    mObjectEditList.add(edit);

}



MtpServer::ObjectEdit* MtpServer::getEditObject(MtpObjectHandle handle) {

    int count = mObjectEditList.size();

    for (int i = 0; i < count; i++) {

        ObjectEdit* edit = mObjectEditList[i];

        if (edit->handle == handle) return edit;

    }

    return NULL;

}



void MtpServer::removeEditObject(MtpObjectHandle handle) {

    int count = mObjectEditList.size();

    for (int i = 0; i < count; i++) {

        ObjectEdit* edit = mObjectEditList[i];

        if (edit->handle == handle) {

            delete edit;

            mObjectEditList.removeAt(i);

            return;

        }

    }

    LOGE("ObjectEdit not found in removeEditObject");

}



void MtpServer::commitEdit(ObjectEdit* edit) {

    mDatabase->endSendObject((const char *)edit->path, edit->handle, edit->format, true);

}





bool MtpServer::handleRequest() {

    Mutex::Autolock autoLock(mMutex);
@@ -322,7 +376,8 @@ bool MtpServer::handleRequest() { 
            response = doGetObject();

            break;

        case MTP_OPERATION_GET_PARTIAL_OBJECT:

            response = doGetPartialObject();

        case MTP_OPERATION_GET_PARTIAL_OBJECT_64:

            response = doGetPartialObject(operation);

            break;

        case MTP_OPERATION_SEND_OBJECT_INFO:

            response = doSendObjectInfo();
@@ -339,6 +394,18 @@ bool MtpServer::handleRequest() { 
        case MTP_OPERATION_GET_DEVICE_PROP_DESC:

            response = doGetDevicePropDesc();

            break;

        case MTP_OPERATION_SEND_PARTIAL_OBJECT:

            response = doSendPartialObject();

            break;

        case MTP_OPERATION_TRUNCATE_OBJECT:

            response = doTruncateObject();

            break;

        case MTP_OPERATION_BEGIN_EDIT_OBJECT:

            response = doBeginEditObject();

            break;

        case MTP_OPERATION_END_EDIT_OBJECT:

            response = doEndEditObject();

            break;

        default:

            LOGE("got unsupported command %s", MtpDebug::getOperationCodeName(operation));

            response = MTP_RESPONSE_OPERATION_NOT_SUPPORTED;
@@ -363,7 +430,7 @@ MtpResponseCode MtpServer::doGetDeviceInfo() { 
    mData.putUInt16(MTP_STANDARD_VERSION);

    mData.putUInt32(6); // MTP Vendor Extension ID

    mData.putUInt16(MTP_STANDARD_VERSION);

    string.set("microsoft.com: 1.0;");

    string.set("microsoft.com: 1.0; android.com: 1.0;");

    mData.putString(string); // MTP Extensions

    mData.putUInt16(0); //Functional Mode

    mData.putAUInt16(kSupportedOperationCodes,
@@ -601,7 +668,40 @@ MtpResponseCode MtpServer::doGetObjectInfo() { 
    if (!hasStorage())

        return MTP_RESPONSE_INVALID_OBJECT_HANDLE;

    MtpObjectHandle handle = mRequest.getParameter(1);

    return mDatabase->getObjectInfo(handle, mData);

    MtpObjectInfo info(handle);

    MtpResponseCode result = mDatabase->getObjectInfo(handle, info);

    if (result == MTP_RESPONSE_OK) {

        char    date[20];



        mData.putUInt32(info.mStorageID);

        mData.putUInt16(info.mFormat);

        mData.putUInt16(info.mProtectionStatus);



        // if object is being edited the database size may be out of date

        uint32_t size = info.mCompressedSize;

        ObjectEdit* edit = getEditObject(handle);

        if (edit)

            size = (edit->size > 0xFFFFFFFFLL ? 0xFFFFFFFF : (uint32_t)edit->size);

        mData.putUInt32(size);



        mData.putUInt16(info.mThumbFormat);

        mData.putUInt32(info.mThumbCompressedSize);

        mData.putUInt32(info.mThumbPixWidth);

        mData.putUInt32(info.mThumbPixHeight);

        mData.putUInt32(info.mImagePixWidth);

        mData.putUInt32(info.mImagePixHeight);

        mData.putUInt32(info.mImagePixDepth);

        mData.putUInt32(info.mParent);

        mData.putUInt16(info.mAssociationType);

        mData.putUInt32(info.mAssociationDesc);

        mData.putUInt32(info.mSequenceNumber);

        mData.putString(info.mName);

        mData.putEmptyString();    // date created

        formatDateTime(info.mDateModified, date, sizeof(date));

        mData.putString(date);   // date modified

        mData.putEmptyString();   // keywords

    }

    return result;

}



MtpResponseCode MtpServer::doGetObject() {
@@ -641,12 +741,22 @@ MtpResponseCode MtpServer::doGetObject() { 
    return MTP_RESPONSE_OK;

}



MtpResponseCode MtpServer::doGetPartialObject() {

MtpResponseCode MtpServer::doGetPartialObject(MtpOperationCode operation) {

    if (!hasStorage())

        return MTP_RESPONSE_INVALID_OBJECT_HANDLE;

    MtpObjectHandle handle = mRequest.getParameter(1);

    uint32_t offset = mRequest.getParameter(2);

    uint32_t length = mRequest.getParameter(3);

    uint64_t offset;

    uint32_t length;

    offset = mRequest.getParameter(2);

    if (operation == MTP_OPERATION_GET_PARTIAL_OBJECT_64) {

        // android extension with 64 bit offset

        uint64_t offset2 = mRequest.getParameter(3);

        offset = offset | (offset2 << 32);

        length = mRequest.getParameter(4);

    } else {

        // standard GetPartialObject

        length = mRequest.getParameter(3);

    }

    MtpString pathBuf;

    int64_t fileLength;

    MtpObjectFormat format;
@@ -933,4 +1043,113 @@ MtpResponseCode MtpServer::doGetDevicePropDesc() { 
    return MTP_RESPONSE_OK;

}



MtpResponseCode MtpServer::doSendPartialObject() {

    if (!hasStorage())

        return MTP_RESPONSE_INVALID_OBJECT_HANDLE;

    MtpObjectHandle handle = mRequest.getParameter(1);

    uint64_t offset = mRequest.getParameter(2);

    uint64_t offset2 = mRequest.getParameter(3);

    offset = offset | (offset2 << 32);

    uint32_t length = mRequest.getParameter(4);



    ObjectEdit* edit = getEditObject(handle);

    if (!edit) {

        LOGE("object not open for edit in doSendPartialObject");

        return MTP_RESPONSE_GENERAL_ERROR;

    }



    // can't start writing past the end of the file

    if (offset > edit->size) {

        LOGD("writing past end of object, offset: %lld, edit->size: %lld", offset, edit->size);

        return MTP_RESPONSE_GENERAL_ERROR;

    }



    // read the header

    int ret = mData.readDataHeader(mFD);

    // FIXME - check for errors here.



    // reset so we don't attempt to send this back

    mData.reset();



    const char* filePath = (const char *)edit->path;

    LOGV("receiving partial %s %lld %ld\n", filePath, offset, length);

    mtp_file_range  mfr;

    mfr.fd = edit->fd;

    mfr.offset = offset;

    mfr.length = length;



    // transfer the file

    ret = ioctl(mFD, MTP_RECEIVE_FILE, (unsigned long)&mfr);

    LOGV("MTP_RECEIVE_FILE returned %d", ret);

    if (ret < 0) {

        mResponse.setParameter(1, 0);

        if (errno == ECANCELED)

            return MTP_RESPONSE_TRANSACTION_CANCELLED;

        else

            return MTP_RESPONSE_GENERAL_ERROR;

    }

    mResponse.setParameter(1, length);

    uint64_t end = offset + length;

    if (end > edit->size) {

        edit->size = end;

    }

    return MTP_RESPONSE_OK;

}



MtpResponseCode MtpServer::doTruncateObject() {

    MtpObjectHandle handle = mRequest.getParameter(1);

    ObjectEdit* edit = getEditObject(handle);

    if (!edit) {

        LOGE("object not open for edit in doTruncateObject");

        return MTP_RESPONSE_GENERAL_ERROR;

    }



    uint64_t offset = mRequest.getParameter(2);

    uint64_t offset2 = mRequest.getParameter(3);

    offset |= (offset2 << 32);

    if (ftruncate(edit->fd, offset) != 0) {

        return MTP_RESPONSE_GENERAL_ERROR;

    } else {

        edit->size = offset;

        return MTP_RESPONSE_OK;

    }

}



MtpResponseCode MtpServer::doBeginEditObject() {

    MtpObjectHandle handle = mRequest.getParameter(1);

    if (getEditObject(handle)) {

        LOGE("object already open for edit in doBeginEditObject");

        return MTP_RESPONSE_GENERAL_ERROR;

    }



    MtpString path;

    int64_t fileLength;

    MtpObjectFormat format;

    int result = mDatabase->getObjectFilePath(handle, path, fileLength, format);

    if (result != MTP_RESPONSE_OK)

        return result;



    int fd = open((const char *)path, O_RDWR | O_EXCL);

    if (fd < 0) {

        LOGE("open failed for %s in doBeginEditObject (%d)", (const char *)path, errno);

        return MTP_RESPONSE_GENERAL_ERROR;

    }



    addEditObject(handle, path, fileLength, format, fd);

    return MTP_RESPONSE_OK;

}



MtpResponseCode MtpServer::doEndEditObject() {

    MtpObjectHandle handle = mRequest.getParameter(1);

    ObjectEdit* edit = getEditObject(handle);

    if (!edit) {

        LOGE("object not open for edit in doEndEditObject");

        return MTP_RESPONSE_GENERAL_ERROR;

    }



    commitEdit(edit);

    removeEditObject(handle);

    return MTP_RESPONSE_OK;

}



}  // namespace android

media/mtp/MtpServer.h

+22 −1
Original line number Diff line number Diff line
@@ -65,6 +65,17 @@ private: 


    Mutex               mMutex;



    // represents an MTP object that is being edited using the android extensions

    // for direct editing (BeginEditObject, SendPartialObject, TruncateObject and EndEditObject)

    struct ObjectEdit {

        MtpObjectHandle     handle;

        MtpString           path;

        uint64_t            size;

        MtpObjectFormat     format;

        int                 fd;

    };

    Vector<ObjectEdit*>  mObjectEditList;



public:

                        MtpServer(int fd, MtpDatabase* database,

                                    int fileGroup, int filePerm, int directoryPerm);
@@ -86,6 +97,12 @@ private: 
    void                sendStoreRemoved(MtpStorageID id);

    void                sendEvent(MtpEventCode code, uint32_t param1);



    void                addEditObject(MtpObjectHandle handle, MtpString& path,

                                uint64_t size, MtpObjectFormat format, int fd);

    ObjectEdit*         getEditObject(MtpObjectHandle handle);

    void                removeEditObject(MtpObjectHandle handle);

    void                commitEdit(ObjectEdit* edit);



    bool                handleRequest();



    MtpResponseCode     doGetDeviceInfo();
@@ -106,12 +123,16 @@ private: 
    MtpResponseCode     doGetObjectPropList();

    MtpResponseCode     doGetObjectInfo();

    MtpResponseCode     doGetObject();

    MtpResponseCode     doGetPartialObject();

    MtpResponseCode     doGetPartialObject(MtpOperationCode operation);

    MtpResponseCode     doSendObjectInfo();

    MtpResponseCode     doSendObject();

    MtpResponseCode     doDeleteObject();

    MtpResponseCode     doGetObjectPropDesc();

    MtpResponseCode     doGetDevicePropDesc();

    MtpResponseCode     doSendPartialObject();

    MtpResponseCode     doTruncateObject();

    MtpResponseCode     doBeginEditObject();

    MtpResponseCode     doEndEditObject();

};



}; // namespace android

media/mtp/mtp.h

+13 −0
Original line number Diff line number Diff line
@@ -391,6 +391,19 @@ 
#define MTP_OPERATION_SET_OBJECT_REFERENCES                 0x9811

#define MTP_OPERATION_SKIP                                  0x9820



// Android extensions for direct file IO



// Same as GetPartialObject, but with 64 bit offset

#define MTP_OPERATION_GET_PARTIAL_OBJECT_64                 0x95C1

// Same as GetPartialObject64, but copying host to device

#define MTP_OPERATION_SEND_PARTIAL_OBJECT                   0x95C2

// Truncates file to 64 bit length

#define MTP_OPERATION_TRUNCATE_OBJECT                       0x95C3

// Must be called before using SendPartialObject and TruncateObject

#define MTP_OPERATION_BEGIN_EDIT_OBJECT                     0x95C4

// Called to commit changes made by SendPartialObject and TruncateObject

#define MTP_OPERATION_END_EDIT_OBJECT                       0x95C5



// MTP Response Codes

#define MTP_RESPONSE_UNDEFINED                                  0x2000

#define MTP_RESPONSE_OK                                         0x2001