[core] Surface cache management APIs

These APIs need to be on the DefaultFileSource in order to
be visible for the SDKs bindings.

include/mbgl/storage/default_file_source.hpp

@@ -144,6 +144,14 @@ public:
      */
     void deleteOfflineRegion(OfflineRegion&&, std::function<void (std::exception_ptr)>);
 
+    /*
+     * Invalidate all the tiles from an offline region forcing Mapbox GL to revalidate
+     * the tiles with the server before using. This is more efficient than deleting the
+     * offline region and downloading it again because if the data on the cache matches
+     * the server, no new data gets transmitted.
+     */
+    void invalidateOfflineRegion(OfflineRegion&, std::function<void (std::exception_ptr)>);
+
     /*
      * Changing or bypassing this limit without permission from Mapbox is prohibited
      * by the Mapbox Terms of Service.
@@ -186,6 +194,26 @@ public:
      */
     void resetCache(std::function<void (std::exception_ptr)>);
 
+    /*
+     * Forces revalidation of tiles in the ambient cache.
+     *
+     * Forces Mapbox GL Native to revalidate tiles stored in the ambient
+     * cache with the tile server before using them, making sure they
+     * are the latest version. This is more efficient than cleaning the
+     * cache because if the tile is considered valid after the server
+     * lookup, it will not get downloaded again.
+     */
+    void invalidateTileCache(std::function<void (std::exception_ptr)>);
+
+    /*
+     * Erase tiles from the ambient cache, freeing storage space.
+     *
+     * Erases the tile cache, freeing resources. This operation can be
+     * potentially slow because it will trigger a VACUUM on SQLite,
+     * forcing the database to move pages on the filesystem.
+     */
+    void clearTileCache(std::function<void (std::exception_ptr)>);
+
     // For testing only.
     void setOnlineStatus(bool);
 

platform/default/src/mbgl/storage/default_file_source.cpp

@@ -87,6 +87,10 @@ public:
         callback(offlineDatabase->deleteRegion(std::move(region)));
     }
 
+    void invalidateRegion(int64_t regionID, std::function<void (std::exception_ptr)> callback) {
+        callback(offlineDatabase->invalidateRegion(regionID));
+    }
+
     void setRegionObserver(int64_t regionID, std::unique_ptr<OfflineRegionObserver> observer) {
         if (auto download = getDownload(regionID)) {
             download.value()->setObserver(std::move(observer));
@@ -184,6 +188,14 @@ public:
         callback(offlineDatabase->resetCache());
     }
 
+    void invalidateTileCache(std::function<void (std::exception_ptr)> callback) {
+        callback(offlineDatabase->invalidateTileCache());
+    }
+
+    void clearTileCache(std::function<void (std::exception_ptr)> callback) {
+        callback(offlineDatabase->clearTileCache());
+    }
+
 private:
     expected<OfflineDownload*, std::exception_ptr> getDownload(int64_t regionID) {
         auto it = downloads.find(regionID);
@@ -295,6 +307,10 @@ void DefaultFileSource::deleteOfflineRegion(OfflineRegion&& region, std::functio
     impl->actor().invoke(&Impl::deleteRegion, std::move(region), callback);
 }
 
+void DefaultFileSource::invalidateOfflineRegion(OfflineRegion& region, std::function<void (std::exception_ptr)> callback) {
+    impl->actor().invoke(&Impl::invalidateRegion, region.getID(), callback);
+}
+
 void DefaultFileSource::setOfflineRegionObserver(OfflineRegion& region, std::unique_ptr<OfflineRegionObserver> observer) {
     impl->actor().invoke(&Impl::setRegionObserver, region.getID(), std::move(observer));
 }
@@ -327,6 +343,14 @@ void DefaultFileSource::resetCache(std::function<void (std::exception_ptr)> call
     impl->actor().invoke(&Impl::resetCache, callback);
 }
 
+void DefaultFileSource::invalidateTileCache(std::function<void (std::exception_ptr)> callback) {
+    impl->actor().invoke(&Impl::invalidateTileCache, callback);
+}
+
+void DefaultFileSource::clearTileCache(std::function<void (std::exception_ptr)> callback) {
+    impl->actor().invoke(&Impl::clearTileCache, callback);
+}
+
 // For testing only:
 
 void DefaultFileSource::setOnlineStatus(const bool status) {