DO NOT MERGE MTP: Implement GetThumb command

This allows the PC to access thumbnails in JPEG files over MTP/PTP

Bug: 3219495

Change-Id: Id61f353ba70e896fae9a47338bf7871c0f185d3e
Signed-off-by: Mike Lockwood <lockwood@android.com>

5 files changed, 34 insertions, 1 deletions

diff --git a/media/mtp/MtpDataPacket.cpp b/media/mtp/MtpDataPacket.cpp
index 0b0c80d..817eac0 100644
--- a/media/mtp/MtpDataPacket.cpp
+++ b/media/mtp/MtpDataPacket.cpp
@@ -388,6 +388,16 @@ int MtpDataPacket::writeDataHeader(int fd, uint32_t length) {
     int ret = ::write(fd, mBuffer, MTP_CONTAINER_HEADER_SIZE);
     return (ret < 0 ? ret : 0);
 }
+
+int MtpDataPacket::writeData(int fd, void* data, uint32_t length) {
+    MtpPacket::putUInt32(MTP_CONTAINER_LENGTH_OFFSET, length + MTP_CONTAINER_HEADER_SIZE);
+    MtpPacket::putUInt16(MTP_CONTAINER_TYPE_OFFSET, MTP_CONTAINER_TYPE_DATA);
+    int ret = ::write(fd, mBuffer, MTP_CONTAINER_HEADER_SIZE);
+    if (ret == MTP_CONTAINER_HEADER_SIZE)
+        ret = ::write(fd, data, length);
+    return (ret < 0 ? ret : 0);
+}
+
 #endif // MTP_DEVICE
 
 #ifdef MTP_HOST
diff --git a/media/mtp/MtpDataPacket.h b/media/mtp/MtpDataPacket.h
index 577cea1..8a08948 100644
--- a/media/mtp/MtpDataPacket.h
+++ b/media/mtp/MtpDataPacket.h
@@ -100,6 +100,7 @@ public:
     // write our data to the given file descriptor
     int                 write(int fd);
     int                 writeDataHeader(int fd, uint32_t length);
+    int                 writeData(int fd, void* data, uint32_t length);
 #endif
 
 #ifdef MTP_HOST
diff --git a/media/mtp/MtpDatabase.h b/media/mtp/MtpDatabase.h
index d7bde00..4e6ac7a 100644
--- a/media/mtp/MtpDatabase.h
+++ b/media/mtp/MtpDatabase.h
@@ -84,6 +84,8 @@ public:
     virtual MtpResponseCode         getObjectInfo(MtpObjectHandle handle,
                                             MtpObjectInfo& info) = 0;
 
+    virtual void*                   getThumbnail(MtpObjectHandle handle, size_t& outThumbSize) = 0;
+
     virtual MtpResponseCode         getObjectFilePath(MtpObjectHandle handle,
                                             MtpString& outFilePath,
                                             int64_t& outFileLength,
diff --git a/media/mtp/MtpServer.cpp b/media/mtp/MtpServer.cpp
index b744b5b..4a8fd3e 100644
--- a/media/mtp/MtpServer.cpp
+++ b/media/mtp/MtpServer.cpp
@@ -50,7 +50,7 @@ static const MtpOperationCode kSupportedOperationCodes[] = {
     MTP_OPERATION_GET_OBJECT_HANDLES,
     MTP_OPERATION_GET_OBJECT_INFO,
     MTP_OPERATION_GET_OBJECT,
-//    MTP_OPERATION_GET_THUMB,
+    MTP_OPERATION_GET_THUMB,
     MTP_OPERATION_DELETE_OBJECT,
     MTP_OPERATION_SEND_OBJECT_INFO,
     MTP_OPERATION_SEND_OBJECT,
@@ -370,6 +370,9 @@ bool MtpServer::handleRequest() {
         case MTP_OPERATION_GET_OBJECT:
             response = doGetObject();
             break;
+        case MTP_OPERATION_GET_THUMB:
+            response = doGetThumb();
+            break;
         case MTP_OPERATION_GET_PARTIAL_OBJECT:
         case MTP_OPERATION_GET_PARTIAL_OBJECT_64:
             response = doGetPartialObject(operation);
@@ -736,6 +739,22 @@ MtpResponseCode MtpServer::doGetObject() {
     return MTP_RESPONSE_OK;
 }
 
+MtpResponseCode MtpServer::doGetThumb() {
+    MtpObjectHandle handle = mRequest.getParameter(1);
+    size_t thumbSize;
+    void* thumb = mDatabase->getThumbnail(handle, thumbSize);
+    if (thumb) {
+        // send data
+        mData.setOperationCode(mRequest.getOperationCode());
+        mData.setTransactionID(mRequest.getTransactionID());
+        mData.writeData(mFD, thumb, thumbSize);
+        free(thumb);
+        return MTP_RESPONSE_OK;
+    } else {
+        return MTP_RESPONSE_GENERAL_ERROR;
+    }
+}
+
 MtpResponseCode MtpServer::doGetPartialObject(MtpOperationCode operation) {
     if (!hasStorage())
         return MTP_RESPONSE_INVALID_OBJECT_HANDLE;
diff --git a/media/mtp/MtpServer.h b/media/mtp/MtpServer.h
index b06eb28..859a18e 100644
--- a/media/mtp/MtpServer.h
+++ b/media/mtp/MtpServer.h
@@ -133,6 +133,7 @@ private:
     MtpResponseCode     doGetObjectPropList();
     MtpResponseCode     doGetObjectInfo();
     MtpResponseCode     doGetObject();
+    MtpResponseCode     doGetThumb();
     MtpResponseCode     doGetPartialObject(MtpOperationCode operation);
     MtpResponseCode     doSendObjectInfo();
     MtpResponseCode     doSendObject();