[core] Extend DefaultFileSource API

Add `packDatabase()` method and `bool pack` argument to the `deleteOfflineRegion()` method.

2 files changed, 32 insertions, 9 deletions

diff --git a/include/mbgl/storage/default_file_source.hpp b/include/mbgl/storage/default_file_source.hpp
index 4f4c7136c6..8fc8ed50df 100644
--- a/include/mbgl/storage/default_file_source.hpp
+++ b/include/mbgl/storage/default_file_source.hpp
@@ -121,6 +121,11 @@ public:
      * Eviction works by removing the least-recently requested resources not also required
      * by other regions, until the database shrinks below a certain size.
      *
+     * If the |pack| argument is `false` the database file packing is skipped and the
+     * database file does not shrink after this operation completes. Database file
+     * packing can be done later with `packDatabase()`. It is a useful optimization
+     * e.g. when several regions should be deleted in a row.
+     *
      * Note that this method takes ownership of the input, reflecting the fact that once
      * region deletion is initiated, it is not legal to perform further actions with the
      * region.
@@ -129,7 +134,7 @@ public:
      * executed on the database thread; it is the responsibility of the SDK bindings
      * to re-execute a user-provided callback on the main thread.
      */
-    void deleteOfflineRegion(OfflineRegion&&, std::function<void (std::exception_ptr)>);
+    void deleteOfflineRegion(OfflineRegion&&, std::function<void(std::exception_ptr)>, bool pack = true);
 
     /*
      * Invalidate all the tiles from an offline region forcing Mapbox GL to revalidate
@@ -137,7 +142,7 @@ public:
      * 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)>);
+    void invalidateOfflineRegion(OfflineRegion&, std::function<void(std::exception_ptr)>);
 
     /*
      * Changing or bypassing this limit without permission from Mapbox is prohibited
@@ -179,7 +184,16 @@ public:
      * executed on the database thread; it is the responsibility of the SDK bindings
      * to re-execute a user-provided callback on the main thread.
      */
-    void resetDatabase(std::function<void (std::exception_ptr)>);
+    void resetDatabase(std::function<void(std::exception_ptr)>);
+
+    /*
+     * Packs the existing database file into a minimal amount of disk space.
+     *
+     * When the operation is complete or encounters an error, the given callback will be
+     * executed on the database thread; it is the responsibility of the SDK bindings
+     * to re-execute a user-provided callback on the main thread.
+     */
+    void packDatabase(std::function<void(std::exception_ptr)> callback);
 
     /*
      * Forces revalidation of the ambient cache.
diff --git a/platform/default/src/mbgl/storage/default_file_source.cpp b/platform/default/src/mbgl/storage/default_file_source.cpp
index dc4b2908a8..3982f3dbc7 100644
--- a/platform/default/src/mbgl/storage/default_file_source.cpp
+++ b/platform/default/src/mbgl/storage/default_file_source.cpp
@@ -82,9 +82,9 @@ public:
         }
     }
 
-    void deleteRegion(OfflineRegion&& region, std::function<void (std::exception_ptr)> callback) {
+    void deleteRegion(OfflineRegion&& region, std::function<void(std::exception_ptr)> callback, bool pack) {
         downloads.erase(region.getID());
-        callback(offlineDatabase->deleteRegion(std::move(region)));
+        callback(offlineDatabase->deleteRegion(std::move(region), pack));
     }
 
     void invalidateRegion(int64_t regionID, std::function<void (std::exception_ptr)> callback) {
@@ -200,6 +200,8 @@ public:
         callback(offlineDatabase->setMaximumAmbientCacheSize(size));
     }
 
+    void packDatabase(std::function<void(std::exception_ptr)> callback) { callback(offlineDatabase->pack()); }
+
 private:
     expected<OfflineDownload*, std::exception_ptr> getDownload(int64_t regionID) {
         auto it = downloads.find(regionID);
@@ -308,11 +310,14 @@ void DefaultFileSource::updateOfflineMetadata(const int64_t regionID,
     impl->actor().invoke(&Impl::updateMetadata, regionID, metadata, callback);
 }
 
-void DefaultFileSource::deleteOfflineRegion(OfflineRegion&& region, std::function<void (std::exception_ptr)> callback) {
-    impl->actor().invoke(&Impl::deleteRegion, std::move(region), callback);
+void DefaultFileSource::deleteOfflineRegion(OfflineRegion&& region,
+                                            std::function<void(std::exception_ptr)> callback,
+                                            bool pack) {
+    impl->actor().invoke(&Impl::deleteRegion, std::move(region), callback, pack);
 }
 
-void DefaultFileSource::invalidateOfflineRegion(OfflineRegion& region, std::function<void (std::exception_ptr)> callback) {
+void DefaultFileSource::invalidateOfflineRegion(OfflineRegion& region,
+                                                std::function<void(std::exception_ptr)> callback) {
     impl->actor().invoke(&Impl::invalidateRegion, region.getID(), callback);
 }
 
@@ -348,11 +353,15 @@ void DefaultFileSource::resetDatabase(std::function<void (std::exception_ptr)> c
     impl->actor().invoke(&Impl::resetDatabase, std::move(callback));
 }
 
+void DefaultFileSource::packDatabase(std::function<void(std::exception_ptr)> callback) {
+    impl->actor().invoke(&Impl::packDatabase, std::move(callback));
+}
+
 void DefaultFileSource::invalidateAmbientCache(std::function<void (std::exception_ptr)> callback) {
     impl->actor().invoke(&Impl::invalidateAmbientCache, std::move(callback));
 }
 
-void DefaultFileSource::clearAmbientCache(std::function<void (std::exception_ptr)> callback) {
+void DefaultFileSource::clearAmbientCache(std::function<void(std::exception_ptr)> callback) {
     impl->actor().invoke(&Impl::clearAmbientCache, std::move(callback));
 }