[evolution-data-server] [CalDAV] Instead of query for UID, try to get the object directly

[Milan Crha <mcrha src gnome org>]

commit 818aa8f4b0b273a615a686e92adb805709297945
Author: Milan Crha <mcrha redhat com>
Date:   Tue Apr 5 22:09:05 2016 +0200

    [CalDAV] Instead of query for UID, try to get the object directly
    
    Neither Google, nor iCloud, like the query based on UID. It's advised
    to try with a direct URI for the object and even it's a guess sometimes,
    it seems to work better for these two.

 calendar/backends/caldav/e-cal-backend-caldav.c |  265 +++++++----------------
 1 files changed, 84 insertions(+), 181 deletions(-)
---
diff --git a/calendar/backends/caldav/e-cal-backend-caldav.c b/calendar/backends/caldav/e-cal-backend-caldav.c
index e74281b..a79ec36 100644
--- a/calendar/backends/caldav/e-cal-backend-caldav.c
+++ b/calendar/backends/caldav/e-cal-backend-caldav.c
@@ -1670,176 +1670,6 @@ caldav_server_list_objects (ECalBackendCalDAV *cbdav,
        return result;
 }
 
-static void
-caldav_synchronize_cache (ECalBackendCalDAV *cbdav,
-                         time_t start_time,
-                         time_t end_time,
-                         gboolean can_check_ctag,
-                         GCancellable *cancellable);
-
-static gboolean
-caldav_server_query_google_for_uid (ECalBackendCalDAV *cbdav,
-                                   const gchar *uid,
-                                   GCancellable *cancellable,
-                                   GError **error)
-{
-       if (!check_calendar_changed_on_server (cbdav, FALSE, cancellable))
-               return FALSE;
-
-       caldav_synchronize_cache (cbdav, 0, 0, FALSE, cancellable);
-
-       return !g_cancellable_is_cancelled (cancellable);
-}
-
-static gboolean
-caldav_server_query_for_uid (ECalBackendCalDAV *cbdav,
-                             const gchar *uid,
-                             GCancellable *cancellable,
-                             GError **error)
-{
-       SoupMessage *message;
-       xmlOutputBufferPtr buf;
-       xmlNodePtr node;
-       xmlNodePtr sn;
-       xmlNodePtr root;
-       xmlDocPtr doc;
-       xmlNsPtr nsdav;
-       xmlNsPtr nscd;
-       gconstpointer buf_content;
-       gsize buf_size;
-       gboolean result = FALSE;
-       gint ii, len = 0;
-       CalDAVObject *objs = NULL, *object;
-
-       g_return_val_if_fail (cbdav != NULL, FALSE);
-       g_return_val_if_fail (E_IS_CAL_BACKEND_CALDAV (cbdav), FALSE);
-       g_return_val_if_fail (uid && *uid, FALSE);
-
-       if (cbdav->priv->is_google)
-               return caldav_server_query_google_for_uid (cbdav, uid, cancellable, error);
-
-       /* Allocate the soup message */
-       message = soup_message_new ("REPORT", cbdav->priv->uri);
-       if (message == NULL)
-               return FALSE;
-
-       /* Maybe we should just do a g_strdup_printf here? */
-       /* Prepare request body */
-       doc = xmlNewDoc ((xmlChar *) "1.0");
-       root = xmlNewDocNode (doc, NULL, (xmlChar *) "calendar-query", NULL);
-       nscd = xmlNewNs (root, (xmlChar *) "urn:ietf:params:xml:ns:caldav", (xmlChar *) "C");
-       xmlSetNs (root, nscd);
-       xmlDocSetRootElement (doc, root);
-
-       /* Add webdav tags */
-       nsdav = xmlNewNs (root, (xmlChar *) "DAV:", (xmlChar *) "D");
-       node = xmlNewTextChild (root, nsdav, (xmlChar *) "prop", NULL);
-       xmlNewTextChild (node, nsdav, (xmlChar *) "getetag", NULL);
-       xmlNewTextChild (node, nscd, (xmlChar *) "calendar-data", NULL);
-
-       node = xmlNewTextChild (root, nscd, (xmlChar *) "filter", NULL);
-       node = xmlNewTextChild (node, nscd, (xmlChar *) "comp-filter", NULL);
-       xmlSetProp (node, (xmlChar *) "name", (xmlChar *) "VCALENDAR");
-
-       sn = xmlNewTextChild (node, nscd, (xmlChar *) "comp-filter", NULL);
-       switch (e_cal_backend_get_kind (E_CAL_BACKEND (cbdav))) {
-               default:
-               case ICAL_VEVENT_COMPONENT:
-                       xmlSetProp (sn, (xmlChar *) "name", (xmlChar *) "VEVENT");
-                       break;
-               case ICAL_VJOURNAL_COMPONENT:
-                       xmlSetProp (sn, (xmlChar *) "name", (xmlChar *) "VJOURNAL");
-                       break;
-               case ICAL_VTODO_COMPONENT:
-                       xmlSetProp (sn, (xmlChar *) "name", (xmlChar *) "VTODO");
-                       break;
-       }
-
-       node = xmlNewTextChild (sn, nscd, (xmlChar *) "prop-filter", NULL);
-       xmlSetProp (node, (xmlChar *) "name", (xmlChar *) "UID");
-
-       sn = xmlNewTextChild (node, nscd, (xmlChar *) "text-match", NULL);
-       xmlSetProp (sn, (xmlChar *) "collation", (xmlChar *) "i;octet");
-       xmlNodeSetContent (sn, (xmlChar *) uid);
-
-       buf = xmlAllocOutputBuffer (NULL);
-       xmlNodeDumpOutput (buf, doc, root, 0, 1, NULL);
-       xmlOutputBufferFlush (buf);
-
-       /* Prepare the soup message */
-       soup_message_headers_append (
-               message->request_headers,
-               "User-Agent", "Evolution/" VERSION);
-       soup_message_headers_append (
-               message->request_headers,
-               "Depth", "1");
-
-       buf_content = compat_libxml_output_buffer_get_content (buf, &buf_size);
-       soup_message_set_request (
-               message,
-               "application/xml",
-               SOUP_MEMORY_COPY,
-               buf_content, buf_size);
-
-       /* Send the request now */
-       send_and_handle_redirection (cbdav, message, NULL, cancellable, error);
-
-       /* Clean up the memory */
-       xmlOutputBufferClose (buf);
-       xmlFreeDoc (doc);
-
-       /* Check the result */
-       if (message->status_code != SOUP_STATUS_MULTI_STATUS) {
-               switch (message->status_code) {
-               case SOUP_STATUS_CANT_RESOLVE:
-               case SOUP_STATUS_CANT_RESOLVE_PROXY:
-               case SOUP_STATUS_CANT_CONNECT:
-               case SOUP_STATUS_CANT_CONNECT_PROXY:
-                       cbdav->priv->opened = FALSE;
-                       update_slave_cmd (cbdav->priv, SLAVE_SHOULD_SLEEP);
-                       e_cal_backend_set_writable (
-                               E_CAL_BACKEND (cbdav), FALSE);
-                       break;
-               case SOUP_STATUS_UNAUTHORIZED:
-               case SOUP_STATUS_FORBIDDEN:
-                       caldav_credentials_required_sync (cbdav, TRUE, FALSE, NULL, NULL);
-                       break;
-               default:
-                       g_warning ("Server did not response with SOUP_STATUS_MULTI_STATUS, but with code %d 
(%s)", message->status_code, soup_status_get_phrase (message->status_code) ? soup_status_get_phrase 
(message->status_code) : "Unknown code");
-                       break;
-               }
-
-               g_object_unref (message);
-               return FALSE;
-       }
-
-       /* Parse the response body */
-       if (parse_report_response (message, &objs, &len)) {
-               result = TRUE;
-
-               for (ii = 0, object = objs; ii < len; ii++, object++) {
-                       if (object->status == 200 && object->href && object->etag && object->cdata && 
*object->cdata) {
-                               icalcomponent *icomp = icalparser_parse_string (object->cdata);
-
-                               if (icomp) {
-                                       put_server_comp_to_cache (cbdav, icomp, object->href, object->etag, 
NULL);
-                                       icalcomponent_free (icomp);
-                               }
-                       }
-
-                       /* these free immediately */
-                       caldav_object_free (object, FALSE);
-               }
-
-               /* cache update done for fetched items */
-               g_free (objs);
-       }
-
-       g_object_unref (message);
-
-       return result;
-}
-
 static gboolean
 caldav_server_download_attachment (ECalBackendCalDAV *cbdav,
                                    const gchar *attachment_uri,
@@ -1912,7 +1742,7 @@ caldav_server_get_object (ECalBackendCalDAV *cbdav,
 
                if (message->status_code == SOUP_STATUS_UNAUTHORIZED || message->status_code == 
SOUP_STATUS_FORBIDDEN)
                        caldav_credentials_required_sync (cbdav, FALSE, FALSE, NULL, NULL);
-               else
+               else if (message->status_code != SOUP_STATUS_NOT_FOUND)
                        g_warning ("Could not fetch object '%s' from server, status:%d (%s)", uri, 
message->status_code, soup_status_get_phrase (message->status_code) ? soup_status_get_phrase 
(message->status_code) : "Unknown code");
                g_object_unref (message);
                g_free (uri);
@@ -1990,12 +1820,27 @@ caldav_post_freebusy (ECalBackendCalDAV *cbdav,
 }
 
 static gchar *
+caldav_gen_file_from_uid (ECalBackendCalDAV *cbdav,
+                         const gchar *uid)
+{
+       gchar *filename, *res;
+
+       if (!uid)
+               return NULL;
+
+       filename = g_strconcat (uid, ".ics", NULL);
+       res = soup_uri_encode (filename, NULL);
+       g_free (filename);
+
+       return res;
+}
+
+static gchar *
 caldav_gen_file_from_uid_cal (ECalBackendCalDAV *cbdav,
                               icalcomponent *icalcomp)
 {
        icalcomponent_kind my_kind;
        const gchar *uid = NULL;
-       gchar *filename, *res;
 
        g_return_val_if_fail (cbdav != NULL, NULL);
        g_return_val_if_fail (icalcomp != NULL, NULL);
@@ -2015,14 +1860,7 @@ caldav_gen_file_from_uid_cal (ECalBackendCalDAV *cbdav,
                uid = icalcomponent_get_uid (icalcomp);
        }
 
-       if (!uid)
-               return NULL;
-
-       filename = g_strconcat (uid, ".ics", NULL);
-       res = soup_uri_encode (filename, NULL);
-       g_free (filename);
-
-       return res;
+       return caldav_gen_file_from_uid (cbdav, uid);
 }
 
 static gboolean
@@ -5095,6 +4933,71 @@ caldav_send_objects (ECalBackendSync *backend,
        *modified_calobj = g_strdup (calobj);
 }
 
+static gboolean
+caldav_server_download_uid (ECalBackendCalDAV *cbdav,
+                           const gchar *uid,
+                           GCancellable *cancellable,
+                           GError **error)
+{
+       CalDAVObject obj;
+       GError *local_error = NULL;
+
+       g_return_val_if_fail (E_IS_CAL_BACKEND_CALDAV (cbdav), FALSE);
+       g_return_val_if_fail (uid != NULL, FALSE);
+
+       obj.href = g_strdup (uid);
+       obj.etag = NULL;
+       obj.status = 0;
+       obj.cdata = NULL;
+
+       if (!caldav_server_get_object (cbdav, &obj, cancellable, &local_error)) {
+               if (g_error_matches (local_error, E_DATA_CAL_ERROR, ObjectNotFound)) {
+                       gchar *file;
+
+                       /* OK, the event was properly created, but cannot be found on the place
+                        * where it was PUT - why didn't server tell us where it saved it? */
+                       g_clear_error (&local_error);
+
+                       /* try whether it's saved as its UID.ics file */
+                       file = caldav_gen_file_from_uid (cbdav, uid);
+                       if (file) {
+                               g_free (obj.href);
+                               obj.href = file;
+
+                               if (!caldav_server_get_object (cbdav, &obj, cancellable, &local_error)) {
+                               }
+                       }
+               }
+       }
+
+       if (!local_error) {
+               icalcomponent *use_comp = NULL;
+
+               if (obj.cdata) {
+                       /* maybe server also modified component, thus rather store the server's */
+                       use_comp = icalparser_parse_string (obj.cdata);
+                       put_comp_to_cache (cbdav, use_comp, obj.href, obj.etag);
+               }
+
+               if (use_comp)
+                       icalcomponent_free (use_comp);
+               else
+                       local_error = EDC_ERROR (ObjectNotFound);
+       }
+
+       if (local_error) {
+               g_propagate_error (error, local_error);
+
+               return FALSE;
+       }
+
+       g_free (obj.href);
+       g_free (obj.etag);
+       g_free (obj.cdata);
+
+       return TRUE;
+}
+
 static void
 caldav_get_object (ECalBackendSync *backend,
                    EDataCal *cal,
@@ -5114,7 +5017,7 @@ caldav_get_object (ECalBackendSync *backend,
 
        if (!icalcomp && e_backend_get_online (E_BACKEND (backend))) {
                /* try to fetch from the server, maybe the event was received only recently */
-               if (caldav_server_query_for_uid (cbdav, uid, cancellable, NULL)) {
+               if (caldav_server_download_uid (cbdav, uid, cancellable, NULL)) {
                        icalcomp = get_comp_from_cache (cbdav, uid, rid, NULL, NULL);
                }
        }