Implement get_file_by_name for windows MTP driver

src/calibre/devices/mtp/windows/device.cpp

@@ -76,7 +76,37 @@ py_get_file(Device *self, PyObject *args) {
     if (!PyArg_ParseTuple(args, "O&O|O", py_to_wchar, &object, &stream, &callback)) return NULL;
     if (callback == NULL || !PyCallable_Check(callback)) callback = NULL;
     return wpd::get_file(self->device, object.ptr(), stream, callback);
-} // }}}
+}
+
+static PyObject*
+get_file_by_name(Device *self, PyObject *args) {
+    PyObject *stream, *callback = NULL, *names;
+    wchar_raii parent_id;
+
+    if (!PyArg_ParseTuple(args, "O&O!O|O", py_to_wchar, &parent_id, &PyTuple_Type, &names, &stream, &callback)) return NULL;
+    CComPtr<IPortableDeviceContent> content;
+    HRESULT hr; bool found = false;
+
+    Py_BEGIN_ALLOW_THREADS;
+    hr = self->device->Content(&content);
+    Py_END_ALLOW_THREADS;
+    if (FAILED(hr)) { hresult_set_exc("Failed to create content interface", hr); return NULL; }
+    for (Py_ssize_t i = 0; i < PyTuple_GET_SIZE(names); i++) {
+        PyObject *k = PyTuple_GET_ITEM(names, i);
+        if (!PyUnicode_Check(k)) { PyErr_SetString(PyExc_TypeError, "names must contain only unicode strings"); return NULL; }
+        pyobject_raii l(PyObject_CallMethod(k, "lower", NULL)); if (!l) return NULL;
+        pyobject_raii object_id(wpd::find_in_parent(content, parent_id.ptr(), l.ptr()));
+        if (!object_id) break;
+        if (!py_to_wchar_(object_id.ptr(), &parent_id)) return NULL;
+        found = true;
+    }
+    if (PyErr_Occurred()) return NULL;
+    if (!found) { PyErr_SetString(PyExc_KeyError, "File not found"); return NULL; }
+    if (callback == NULL || !PyCallable_Check(callback)) callback = NULL;
+    return wpd::get_file(self->device, parent_id.ptr(), stream, callback);
+}
+
+// }}}
 
 // list_folder_by_name() {{{
 
@@ -116,6 +146,7 @@ get_metadata_by_name(Device *self, PyObject *args) {
     wchar_raii parent_id; PyObject *names;
     CComPtr<IPortableDeviceContent> content;
     HRESULT hr; bool found = false;
+    if (!PyArg_ParseTuple(args, "O&O!", py_to_wchar, &parent_id, &PyTuple_Type, &names)) return NULL;
 
     Py_BEGIN_ALLOW_THREADS;
     hr = self->device->Content(&content);
@@ -123,7 +154,6 @@ get_metadata_by_name(Device *self, PyObject *args) {
     if (FAILED(hr)) { hresult_set_exc("Failed to create content interface", hr); return NULL; }
 
 
-    if (!PyArg_ParseTuple(args, "O&O!", py_to_wchar, &parent_id, &PyTuple_Type, &names)) return NULL;
     for (Py_ssize_t i = 0; i < PyTuple_GET_SIZE(names); i++) {
         PyObject *k = PyTuple_GET_ITEM(names, i);
         if (!PyUnicode_Check(k)) { PyErr_SetString(PyExc_TypeError, "names must contain only unicode strings"); return NULL; }
@@ -190,6 +220,11 @@ static PyMethodDef Device_methods[] = {
      "get_file(object_id, stream, callback=None) -> Get the file identified by object_id from the device. The file is written to the stream object, which must be a file like object. If callback is not None, it must be a callable that accepts two arguments: (bytes_read, total_size). It will be called after each chunk is read from the device. Note that it can be called multiple times with the same values."
     },
 
+    {"get_file_by_name", (PyCFunction)get_file_by_name, METH_VARARGS,
+     "get_file_by_name(storage_id, parent_id, names, stream, callback=None) -> Get the file specified by names (a tuple of name components) relative to parent_id from the device. stream must be a file-like object. The file will be written to it. callback works the same as in get_filelist()."
+    },
+
+
     {"create_folder", (PyCFunction)py_create_folder, METH_VARARGS,
      "create_folder(parent_id, name) -> Create a folder. Returns the folder metadata."
     },

src/calibre/devices/mtp/windows/driver.py

@@ -5,6 +5,7 @@ __license__   = 'GPL v3'
 __copyright__ = '2012, Kovid Goyal <kovid at kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
+import os
 import threading
 import time
 import traceback
@@ -409,6 +410,26 @@ class MTP_DEVICE(MTPDeviceBase):
             raise DeviceError(f'Could not find folder named: {"/".join(names)} in {parent.full_path}')
         return x
 
+    @same_thread
+    def get_mtp_file_by_name(self, parent, *names: str, stream=None, callback=None):
+        if not parent.is_folder:
+            raise ValueError(f'{parent.full_path} is not a folder')
+        set_name = stream is None
+        if stream is None:
+            stream = SpooledTemporaryFile(5*1024*1024, '_wpd_receive_file.dat')
+        try:
+            try:
+                self.dev.get_file_by_name(parent.object_id, names, stream, callback)
+            except self.wpd.WPDFileBusy:
+                time.sleep(2)
+                self.dev.get_file_by_name(parent.object_id, names, stream, callback)
+        except Exception as e:
+            raise DeviceError(f'Failed to fetch the file {os.sep.join(names)} from {parent.full_path} with error: {as_unicode(e)}')
+        stream.seek(0)
+        if set_name:
+            stream.name = '/'.join(names)
+        return stream
+
     @same_thread
     def get_mtp_file(self, f, stream=None, callback=None):
         if f.is_folder: