Start of support for sync-collection report for webdav-sync extension.

dba/patches/1.2.7.sql

@@ -0,0 +1,65 @@
+
+-- This database update refines the constraint on usr in order to try and be
+-- able to actually DELETE FROM usr WHERE user_no = x; and have the database
+-- do the right thing...
+
+BEGIN;
+SELECT check_db_revision(1,2,6);
+
+CREATE TABLE sync_tokens (
+  sync_token SERIAL PRIMARY KEY,
+  collection_id INT8 REFERENCES collection(collection_id) ON DELETE CASCADE ON UPDATE CASCADE,
+  modification_time TIMESTAMP WITH TIME ZONE DEFAULT current_timestamp
+);
+
+CREATE TABLE sync_changes (
+  sync_time TIMESTAMP WITH TIME ZONE DEFAULT current_timestamp,
+  status INT2,
+  dav_id INT8 REFERENCES calendar_item(dav_id)
+);
+
+SELECT new_db_revision(1,2,7, 'Juli' );
+
+COMMIT;
+ROLLBACK;
+
+
+CREATE or REPLACE FUNCTION write_sync_change( INT8, INT, TEXT ) RETURNS BOOLEAN AS $$
+DECLARE
+  in_collection_id ALIAS FOR $1;
+  in_status ALIAS FOR $2;
+  in_dav_name ALIAS FOR $3;
+  tmp_int INT8;
+BEGIN
+  SELECT 1 INTO tmp_int FROM sync_tokens
+           WHERE collection_id = in_collection_id
+           LIMIT 1;
+  IF NOT FOUND THEN
+    RETURN FALSE;
+  END IF;
+  SELECT dav_id INTO tmp_int FROM calendar_item WHERE dav_name = in_dav_name;
+  INSERT INTO sync_changes ( collection_id, status, dav_id)
+                     VALUES( in_collection_id, in_status::INT2, tmp_int);
+  RETURN TRUE;
+END
+$$ LANGUAGE 'PlPgSQL' VOLATILE STRICT;
+
+
+CREATE or REPLACE FUNCTION new_sync_token( INT8, INT8 ) RETURNS INT8 AS $$
+DECLARE
+  in_old_sync_token ALIAS FOR $1;
+  in_collection_id ALIAS FOR $2;
+  tmp_int INT8;
+BEGIN
+  SELECT 1 INTO tmp_int FROM sync_changes
+          WHERE collection_id = in_collection_id
+            AND sync_time > (SELECT modification_time FROM sync_tokens WHERE sync_token = in_old_sync_token)
+          LIMIT 1;
+  IF NOT FOUND THEN
+    RETURN in_old_sync_token;
+  END IF;
+  SELECT nextval('dav_id_seq') INTO tmp_int;
+  INSERT INTO sync_tokens(collection_id, sync_token) VALUES( in_collection_id, tmp_int );
+  RETURN tmp_int;
+END
+$$ LANGUAGE 'PlPgSQL' STRICT;