patches/15_read_chunks.patch

Index: src/libmtp.c
===================================================================
--- src/libmtp.c	(revision 167447)
+++ src/libmtp.c	(working copy)
@@ -4972,6 +4972,56 @@
 }
 
 /**
+ * This copies a chunk of a file off the device to memory.
+ * @param device a pointer to the device to get the track from.
+ * @param id the file ID of the file to retrieve.
+ * @param offset the offset of the file to read from.
+ * @param count the amount of data to read.
+ * @param data a pointer to the data from the device. Must be
+ *             <coded>free()</code>:ed by the caller after use.
+ * @param datalen the amount of data written to <code>data</code>.
+ * @return 0 if the transfer was successful, any other value means
+ *           failure.
+ */
+int LIBMTP_Get_File_Chunk(LIBMTP_mtpdevice_t* device, uint32_t id,
+                          uint32_t offset, uint32_t count,
+                          unsigned char** data, uint32_t* datalen)
+{
+  uint16_t ret;
+  PTPParams *params = (PTPParams *) device->params;
+  PTP_USB *ptp_usb = (PTP_USB*) device->usbinfo;
+  PTPObject *ob;
+
+  if (!data || !datalen) {
+    add_error_to_errorstack(device, LIBMTP_ERROR_GENERAL, "LIBMTP_Get_File_Chunk(): Invalid parameter.");
+    return -1;
+  }
+
+  ret = ptp_object_want (params, id, PTPOBJECT_OBJECTINFO_LOADED, &ob);
+  if (ret != PTP_RC_OK) {
+    add_error_to_errorstack(device, LIBMTP_ERROR_GENERAL, "LIBMTP_Get_File_Chunk(): Could not get object info.");
+    return -1;
+  }
+  if (ob->oi.ObjectFormat == PTP_OFC_Association) {
+    add_error_to_errorstack(device, LIBMTP_ERROR_GENERAL, "LIBMTP_Get_File_Chunk(): Bad object format.");
+    return -1;
+  }
+
+  ret = ptp_getpartialobject(params, id, offset, count, data, datalen);
+
+  if (ret == PTP_ERROR_CANCEL) {
+    add_error_to_errorstack(device, LIBMTP_ERROR_CANCELLED, "LIBMTP_Get_File_Chunk(): Cancelled transfer.");
+    return -1;
+  }
+  if (ret != PTP_RC_OK) {
+    add_ptp_error_to_errorstack(device, ret, "LIBMTP_Get_File_Chunk(): Could not get file from device.");
+    return -1;
+  }
+
+  return 0;
+}
+
+/**
  * This is a manual conversion from MTPDataGetFunc to PTPDataGetFunc
  * to isolate the internal type.
  */
Index: src/libmtp.h
===================================================================
--- src/libmtp.h	(revision 167447)
+++ src/libmtp.h	(working copy)
@@ -876,6 +876,8 @@
 					     uint32_t const,
 					     uint32_t const);
 LIBMTP_file_t *LIBMTP_Get_Filemetadata(LIBMTP_mtpdevice_t *, uint32_t const);
+int LIBMTP_Get_File_Chunk(LIBMTP_mtpdevice_t*, uint32_t, uint32_t, uint32_t,
+                          unsigned char**, uint32_t*);
 int LIBMTP_Get_File_To_File(LIBMTP_mtpdevice_t*, uint32_t, char const * const,
 			LIBMTP_progressfunc_t const, void const * const);
 int LIBMTP_Get_File_To_File_Descriptor(LIBMTP_mtpdevice_t*,
Index: src/libmtp.h.in
===================================================================
--- src/libmtp.h.in	(revision 167447)
+++ src/libmtp.h.in	(working copy)
@@ -876,6 +876,8 @@
 					     uint32_t const,
 					     uint32_t const);
 LIBMTP_file_t *LIBMTP_Get_Filemetadata(LIBMTP_mtpdevice_t *, uint32_t const);
+int LIBMTP_Get_File_Chunk(LIBMTP_mtpdevice_t*, uint32_t, uint32_t, uint32_t,
+                          unsigned char**, uint32_t*);
 int LIBMTP_Get_File_To_File(LIBMTP_mtpdevice_t*, uint32_t, char const * const,
 			LIBMTP_progressfunc_t const, void const * const);
 int LIBMTP_Get_File_To_File_Descriptor(LIBMTP_mtpdevice_t*,
Index: src/libmtp.sym
===================================================================
--- src/libmtp.sym	(revision 167447)
+++ src/libmtp.sym	(working copy)
@@ -49,6 +49,7 @@
 LIBMTP_Get_Filelisting_With_Callback
 LIBMTP_Get_Files_And_Folders
 LIBMTP_Get_Filemetadata
+LIBMTP_Get_File_Chunk
 LIBMTP_Get_File_To_File
 LIBMTP_Get_File_To_File_Descriptor
 LIBMTP_Get_File_To_Handler