[core] Refactor getRegionCompletedStatus; add completedTileCount; add tests

1 files changed, 10 insertions, 2 deletions

diff --git a/include/mbgl/storage/offline.hpp b/include/mbgl/storage/offline.hpp
index 2c6ca05eec..fc0bf7f01e 100644
--- a/include/mbgl/storage/offline.hpp
+++ b/include/mbgl/storage/offline.hpp
@@ -93,12 +93,20 @@ public:
     uint64_t completedResourceCount = 0;
 
     /**
-     * The cumulative size, in bytes, of all resources (inclusive of tiles) that have been fully downloaded.
+     * The cumulative size, in bytes, of all resources (inclusive of tiles) that have
+     * been fully downloaded.
      */
     uint64_t completedResourceSize = 0;
-    
+
+    /**
+     * The number of tiles that are known to be required for this region. This is a
+     * subset of `completedResourceCount`.
+     */
+    uint64_t completedTileCount = 0;
+
     /**
      * The cumulative size, in bytes, of all tiles that have been fully downloaded.
+     * This is a subset of `completedResourceSize`.
      */
     uint64_t completedTileSize = 0;