[gnome-documents] miner: add a versioning system to the mining operation

[Cosimo Cecchi <cosimoc src gnome org>]

commit c73d00248bb561efe7c921984dd7448bb65aa9bd
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Mon Apr 1 18:20:58 2013 -0400

    miner: add a versioning system to the mining operation
    
    It's useful to have a way to associate a full reindex of an online
    resource to a programmatic change in the code, since we avoid
    updating information for entries that haven't changed by looking at
    their mtime.
    
    Add support for this. Right now the version of all the miners is set to
    one, and is one by default, so nothing will be reindexed just yet.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=696928

 src/miner/gd-gdata-miner.c |    1 +
 src/miner/gd-miner.c       |   39 ++++++++++++++++++++++++++++++++-------
 src/miner/gd-miner.h       |    2 ++
 src/miner/gd-zpj-miner.c   |    1 +
 4 files changed, 36 insertions(+), 7 deletions(-)
---
diff --git a/src/miner/gd-gdata-miner.c b/src/miner/gd-gdata-miner.c
index 508cf54..65ae1d6 100644
--- a/src/miner/gd-gdata-miner.c
+++ b/src/miner/gd-gdata-miner.c
@@ -367,6 +367,7 @@ gd_gdata_miner_class_init (GdGDataMinerClass *klass)
 
   miner_class->goa_provider_type = "google";
   miner_class->miner_identifier = MINER_IDENTIFIER;
+  miner_class->version = 1;
 
   miner_class->create_service = create_service;
   miner_class->query = query_gdata;
diff --git a/src/miner/gd-miner.c b/src/miner/gd-miner.c
index df13d93..88ef522 100644
--- a/src/miner/gd-miner.c
+++ b/src/miner/gd-miner.c
@@ -54,6 +54,7 @@ gd_account_miner_job_free (GdAccountMinerJob *job)
   g_clear_object (&job->async_result);
 
   g_free (job->datasource_urn);
+  g_free (job->root_element_urn);
 
   g_hash_table_unref (job->previous_resources);
 
@@ -172,15 +173,17 @@ gd_account_miner_job_ensure_datasource (GdAccountMinerJob *job,
                                         GError **error)
 {
   GString *datasource_insert;
+  GdMinerClass *klass = GD_MINER_GET_CLASS (job->miner);
 
   datasource_insert = g_string_new (NULL);
   g_string_append_printf (datasource_insert,
                           "INSERT OR REPLACE INTO <%s> {"
-                          "  <%s> a nie:DataSource ; nao:identifier \"%s\""
+                          "  <%s> a nie:DataSource ; nao:identifier \"%s\" . "
+                          "  <%s> a nie:InformationElement ; nie:rootElementOf <%s> ; nie:version \"%d\""
                           "}",
                           job->datasource_urn,
-                          job->datasource_urn,
-                          GD_MINER_GET_CLASS (job->miner)->miner_identifier);
+                          job->datasource_urn, klass->miner_identifier,
+                          job->root_element_urn, job->datasource_urn, klass->version);
 
   tracker_sparql_connection_update (job->connection,
                                     datasource_insert->str,
@@ -376,6 +379,8 @@ gd_account_miner_job_new (GdMiner *self,
   retval->service = miner_class->create_service (self, object);
   retval->datasource_urn = g_strdup_printf ("gd:goa-account:%s",
                                             goa_account_get_id (retval->account));
+  retval->root_element_urn = g_strdup_printf ("gd:goa-account:%s:root-element",
+                                              goa_account_get_id (retval->account));
 
   return retval;
 }
@@ -543,16 +548,20 @@ cleanup_job (GIOSchedulerJob *sched_job,
   GString *select;
   GError *error = NULL;
   TrackerSparqlCursor *cursor;
-  const gchar *datasource;
+  const gchar *datasource, *old_version_str;
+  gint old_version;
   GList *element;
   CleanupJob *job = user_data;
   GdMiner *self = job->self;
+  GdMinerClass *klass = GD_MINER_GET_CLASS (self);
 
   /* find all our datasources in the tracker DB */
   select = g_string_new (NULL);
-  g_string_append_printf (select, "SELECT ?datasource WHERE { ?datasource a nie:DataSource . "
-                          "?datasource nao:identifier \"%s\" }",
-                          GD_MINER_GET_CLASS (self)->miner_identifier);
+  g_string_append_printf (select, "SELECT ?datasource nie:version(?root) WHERE { "
+                          "?datasource a nie:DataSource . "
+                          "?datasource nao:identifier \"%s\" . "
+                          "OPTIONAL { ?root nie:rootElementOf ?datasource } }",
+                          klass->miner_identifier);
 
   cursor = tracker_sparql_connection_query (self->priv->connection,
                                             select->str,
@@ -574,6 +583,8 @@ cleanup_job (GIOSchedulerJob *sched_job,
        * documents, in case the switch has been disabled in System Settings.
        * In fact, we only remove all the account data in case the account
        * is really removed from the panel.
+       *
+       * Also, cleanup sources for which the version has increased.
        */
       datasource = tracker_sparql_cursor_get_string (cursor, 0, NULL);
       element = g_list_find_custom (job->acc_objects, datasource,
@@ -582,6 +593,20 @@ cleanup_job (GIOSchedulerJob *sched_job,
       if (element == NULL)
         job->old_datasources = g_list_prepend (job->old_datasources,
                                                g_strdup (datasource));
+
+      old_version_str = tracker_sparql_cursor_get_string (cursor, 1, NULL);
+      if (old_version_str == NULL)
+        old_version = 1;
+      else
+        sscanf (old_version_str, "%d", &old_version);
+
+      g_debug ("Stored version: %d - new version %d", old_version, klass->version);
+
+      if ((element == NULL) || (old_version < klass->version))
+        {
+          job->old_datasources = g_list_prepend (job->old_datasources,
+                                                 g_strdup (datasource));
+        }
     }
 
   g_object_unref (cursor);
diff --git a/src/miner/gd-miner.h b/src/miner/gd-miner.h
index 9a0b2e8..f16b780 100644
--- a/src/miner/gd-miner.h
+++ b/src/miner/gd-miner.h
@@ -57,6 +57,7 @@ typedef struct {
 
   GHashTable *previous_resources;
   gchar *datasource_urn;
+  gchar *root_element_urn;
 } GdAccountMinerJob;
 
 struct _GdMiner
@@ -72,6 +73,7 @@ struct _GdMinerClass
 
   char *goa_provider_type;
   char *miner_identifier;
+  gint  version;
 
   GObject * (*create_service) (GdMiner *self,
                                GoaObject *object);
diff --git a/src/miner/gd-zpj-miner.c b/src/miner/gd-zpj-miner.c
index f9f598b..fa4fe78 100644
--- a/src/miner/gd-zpj-miner.c
+++ b/src/miner/gd-zpj-miner.c
@@ -281,6 +281,7 @@ gd_zpj_miner_class_init (GdZpjMinerClass *klass)
 
   miner_class->goa_provider_type = "windows_live";
   miner_class->miner_identifier = MINER_IDENTIFIER;
+  miner_class->version = 1;
 
   miner_class->create_service = create_service;
   miner_class->query = query_zpj;