[tracker/wip/carlosg/prune-batch] libtracker-sparql/direct: Prune content of already executed batches

[Carlos Garnacho <carlosg src gnome org>]

commit 944988326dda228c3257df4cefd0e98ca86a648c
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue Sep 27 13:46:10 2022 +0200

    libtracker-sparql/direct: Prune content of already executed batches
    
    When using TrackerBatch from a garbage collected language, we have
    little control over the actual lifetime of a batch object, while
    at the same time we keep the GC unaware about how much memory does
    really depend on that object. This may cause RAM usage spikes when
    the GC hoards too many already executed batches during intensive
    data insertion.
    
    A TrackerBatch is a single-use object though, in order to ease this
    memory usage, we can dispose early of all inserted resources and
    SPARQL updates right after execution, so the TrackerBatch is left a
    husk when all that is left to do with it is freeing it.

 src/libtracker-sparql/direct/tracker-direct-batch.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/src/libtracker-sparql/direct/tracker-direct-batch.c 
b/src/libtracker-sparql/direct/tracker-direct-batch.c
index bf3d04b66..cab313836 100644
--- a/src/libtracker-sparql/direct/tracker-direct-batch.c
+++ b/src/libtracker-sparql/direct/tracker-direct-batch.c
@@ -242,6 +242,8 @@ tracker_direct_batch_update (TrackerDirectBatch  *batch,
                        break;
        }
 
+       g_array_set_size (priv->array, 0);
+
        if (!inner_error)
                tracker_data_update_buffer_flush (data, &inner_error);