[rhythmbox] transfer-target: add prepare and upload methods

[Jonathan Matthew <jmatthew src gnome org>]

commit 14c9fbbbfe87cda73205f8501372339a7de94180
Author: Jonathan Matthew <jonathan d14n org>
Date:   Thu Oct 21 14:58:42 2021 +1000

    transfer-target: add prepare and upload methods
    
    These are called from task threads (using the signals just added
    to RBTrackTransferBatch).  If the target has an upload method,
    always use a temporary file as the destination for the transfer,
    so the target doesn't need to have a build_dest_uri method.

 sources/rb-transfer-target.c | 85 ++++++++++++++++++++++++++++++++++++++++++++
 sources/rb-transfer-target.h | 20 +++++++++++
 2 files changed, 105 insertions(+)
---
diff --git a/sources/rb-transfer-target.c b/sources/rb-transfer-target.c
index 0692576e3..41228710d 100644
--- a/sources/rb-transfer-target.c
+++ b/sources/rb-transfer-target.c
@@ -88,6 +88,10 @@ rb_transfer_target_build_dest_uri (RBTransferTarget *target,
        RBTransferTargetInterface *iface = RB_TRANSFER_TARGET_GET_IFACE (target);
        char *uri;
 
+       /* if we require a separate upload step, always transfer to a temporary file */
+       if (iface->track_upload)
+               return g_strdup (RB_ENCODER_DEST_TEMPFILE);
+
        uri = iface->build_dest_uri (target, entry, media_type, extension);
        if (uri != NULL) {
                rb_debug ("built dest uri for media type '%s', extension '%s': %s",
@@ -100,6 +104,54 @@ rb_transfer_target_build_dest_uri (RBTransferTarget *target,
        return uri;
 }
 
+/**
+ * rb_transfer_target_track_prepare:
+ * @target: an #RBTransferTarget
+ * @entry: the source #RhythmDBEntry for the transfer
+ * @uri: the destination URI
+ * @error: returns error information
+ *
+ * Performs any preparation necessary before starting the transfer.
+ * This is called on a task thread, so no UI interaction is possible.
+ *
+ */
+void
+rb_transfer_target_track_prepare (RBTransferTarget *target,
+                                 RhythmDBEntry *entry,
+                                 const char *uri,
+                                 GError **error)
+{
+       RBTransferTargetInterface *iface = RB_TRANSFER_TARGET_GET_IFACE (target);
+       if (iface->track_prepare)
+               iface->track_prepare (target, entry, uri, error);
+}
+
+/**
+ * rb_transfer_target_track_upload:
+ * @target: an #RBTransferTarget
+ * @entry: the source #RhythmDBEntry for the transfer
+ * @uri: the destination URI
+ * @dest_size: the size of the destination file
+ * @media_type: the media type of the destination file
+ * @error: returns error information
+ *
+ * This is called after a transfer to a temporary file has finished,
+ * allowing the transfer target to upload the file to a device or a
+ * remote service.
+ */
+void
+rb_transfer_target_track_upload (RBTransferTarget *target,
+                                RhythmDBEntry *entry,
+                                const char *uri,
+                                guint64 dest_size,
+                                const char *media_type,
+                                GError **error)
+{
+       RBTransferTargetInterface *iface = RB_TRANSFER_TARGET_GET_IFACE (target);
+       g_assert (iface->track_upload != NULL);
+       iface->track_upload (target, entry, uri, dest_size, media_type, error);
+}
+
 /**
  * rb_transfer_target_track_added:
  * @target: an #RBTransferTarget
@@ -344,6 +396,35 @@ get_dest_uri_cb (RBTrackTransferBatch *batch,
        return uri;
 }
 
+static void
+track_prepare_cb (RBTrackTransferBatch *batch,
+                 GTask *task,
+                 RhythmDBEntry *entry,
+                 const char *uri,
+                 RBTransferTarget *target)
+{
+       GError *error = NULL;
+       rb_transfer_target_track_prepare (target, entry, uri, &error);
+       if (error != NULL)
+               g_task_return_error (task, error);
+}
+
+static void
+track_postprocess_cb (RBTrackTransferBatch *batch,
+                     GTask *task,
+                     RhythmDBEntry *entry,
+                     const char *uri,
+                     guint64 dest_size,
+                     const char *media_type,
+                     RBTransferTarget *target)
+{
+       GError *error = NULL;
+
+       rb_transfer_target_track_upload (target, entry, uri, dest_size, media_type, &error);
+       if (error != NULL)
+               g_task_return_error (task, error);
+}
+
 static void
 track_done_cb (RBTrackTransferBatch *batch,
               RhythmDBEntry *entry,
@@ -382,6 +463,7 @@ track_done_cb (RBTrackTransferBatch *batch,
 RBTrackTransferBatch *
 rb_transfer_target_transfer (RBTransferTarget *target, GSettings *settings, GList *entries, gboolean defer)
 {
+       RBTransferTargetInterface *iface = RB_TRANSFER_TARGET_GET_IFACE (target);
        RBTrackTransferQueue *xferq;
        RBTaskList *tasklist;
        RBShell *shell;
@@ -406,6 +488,9 @@ rb_transfer_target_transfer (RBTransferTarget *target, GSettings *settings, GLis
                batch = rb_track_transfer_batch_new (NULL, settings, NULL, G_OBJECT (target), G_OBJECT 
(xferq));
 
                g_signal_connect_object (batch, "get-dest-uri", G_CALLBACK (get_dest_uri_cb), target, 0);
+               g_signal_connect_object (batch, "track-prepare", G_CALLBACK (track_prepare_cb), target, 0);
+               if (iface->track_upload)
+                       g_signal_connect_object (batch, "track-postprocess", G_CALLBACK 
(track_postprocess_cb), target, 0);
                g_signal_connect_object (batch, "track-done", G_CALLBACK (track_done_cb), target, 0);
        } else {
                start_batch = TRUE;
diff --git a/sources/rb-transfer-target.h b/sources/rb-transfer-target.h
index 15f2adc4b..6331eb980 100644
--- a/sources/rb-transfer-target.h
+++ b/sources/rb-transfer-target.h
@@ -49,6 +49,16 @@ struct _RBTransferTargetInterface
                                                 RhythmDBEntry *entry,
                                                 const char *media_type,
                                                 const char *extension);
+       void            (*track_prepare)        (RBTransferTarget *target,
+                                                RhythmDBEntry *entry,
+                                                const char *uri,
+                                                GError **error);
+       void            (*track_upload)         (RBTransferTarget *target,
+                                                RhythmDBEntry *entry,
+                                                const char *uri,
+                                                guint64 dest_size,
+                                                const char *media_type,
+                                                GError **error);
        gboolean        (*track_added)          (RBTransferTarget *target,
                                                 RhythmDBEntry *entry,
                                                 const char *uri,
@@ -68,6 +78,16 @@ char*                rb_transfer_target_build_dest_uri       (RBTransferTarget *target,
                                                         RhythmDBEntry *entry,
                                                         const char *media_type,
                                                         const char *extension);
+void           rb_transfer_target_track_prepare        (RBTransferTarget *target,
+                                                        RhythmDBEntry *entry,
+                                                        const char *uri,
+                                                        GError **error);
+void           rb_transfer_target_track_upload         (RBTransferTarget *target,
+                                                        RhythmDBEntry *entry,
+                                                        const char *uri,
+                                                        guint64 dest_size,
+                                                        const char *media_type,
+                                                        GError **error);
 void           rb_transfer_target_track_added          (RBTransferTarget *target,
                                                         RhythmDBEntry *entry,
                                                         const char *uri,