log-walker: Keep a list of (iter, count) tuples

This represents the order in which events were handed over to the user
from each iterator. Lets say we have 10 events numbered from 0 to 9,
with 0 being the oldest and 9 the latest event, and we have 3
iterators Ia, Ib and Ic. If they were returned in batches of 5 as:
+-----+--------+
|event|iterator|
+-----+--------+
|  5  |   Ia   |
|  6  |   Ib   |
|  7  |   Ia   |
|  8  |   Ia   |
|  9  |   Ic   |
+ - - + - -- - +
|  0  |   Ic   |
|  1  |   Ic   |
|  2  |   Ib   |
|  3  |   Ib   |
|  4  |   Ia   |
+-----+--------+
Then the list would be:
(Ic, 2), (Ib, 2), (Ia, 2), (Ib, 1), (Ia, 2), (Ic, 1)

Fixes: https://bugs.freedesktop.org/41772

1 files changed, 45 insertions, 0 deletions

diff --git a/telepathy-logger/log-walker.c b/telepathy-logger/log-walker.c
index 9abc2e0..d9cbf1b 100644
--- a/telepathy-logger/log-walker.c
+++ b/telepathy-logger/log-walker.c
@@ -44,6 +44,7 @@
 struct _TplLogWalkerPriv
 {
   GList *caches;
+  GList *history;
   GList *iters;
   GMutex mutex;
   gboolean is_begin;
@@ -63,6 +64,12 @@ typedef struct
   guint num_events;
 } TplLogWalkerAsyncData;
 
+typedef struct
+{
+  TplLogIter *iter;
+  guint count;
+} TplLogWalkerHistoryData;
+
 
 static TplLogWalkerAsyncData *
 tpl_log_walker_async_data_new (void)
@@ -78,6 +85,21 @@ tpl_log_walker_async_data_free (TplLogWalkerAsyncData *data)
 }
 
 
+static TplLogWalkerHistoryData *
+tpl_log_walker_history_data_new (void)
+{
+  return g_slice_new0 (TplLogWalkerHistoryData);
+}
+
+
+static void
+tpl_log_walker_history_data_free (TplLogWalkerHistoryData *data)
+{
+  g_object_unref (data->iter);
+  g_slice_free (TplLogWalkerHistoryData, data);
+}
+
+
 static void
 tpl_log_walker_async_operation_cb (GObject *source_object,
     GAsyncResult *result,
@@ -125,10 +147,12 @@ tpl_log_walker_get_events (TplLogWalker *walker,
       GList *l;
       GList **latest_cache;
       GList *latest_event;
+      TplLogIter *latest_iter;
       gint64 latest_timestamp;
 
       latest_cache = NULL;
       latest_event = NULL;
+      latest_iter = NULL;
       latest_timestamp = 0;
 
       for (k = priv->caches, l = priv->iters;
@@ -157,15 +181,32 @@ tpl_log_walker_get_events (TplLogWalker *walker,
             {
               latest_cache = cache;
               latest_event = event;
+              latest_iter = iter;
               latest_timestamp = timestamp;
             }
         }
 
       if (latest_event != NULL)
         {
+          GList *h;
+          TplLogWalkerHistoryData *data;
+
           *latest_cache = g_list_remove_link (*latest_cache, latest_event);
           events = g_list_prepend (events, latest_event->data);
           i++;
+
+          h = priv->history;
+          if (h == NULL ||
+              ((TplLogWalkerHistoryData *) h->data)->iter != latest_iter)
+            {
+              data = tpl_log_walker_history_data_new ();
+              data->iter = g_object_ref (latest_iter);
+              priv->history = g_list_prepend (priv->history, data);
+            }
+          else
+            data = (TplLogWalkerHistoryData *) h->data;
+
+          data->count++;
         }
       else
         priv->is_end = TRUE;
@@ -217,6 +258,10 @@ tpl_log_walker_dispose (GObject *object)
   g_list_free_full (priv->caches, tpl_log_walker_caches_free_func);
   priv->caches = NULL;
 
+  g_list_free_full (priv->history,
+      (GDestroyNotify) tpl_log_walker_history_data_free);
+  priv->history = NULL;
+
   g_list_free_full (priv->iters, g_object_unref);
   priv->iters = NULL;