[core] Introduce resetCache API

Add an API to delete existing database and re-initialize.

7 files changed, 45 insertions, 2 deletions

diff --git a/include/mbgl/storage/default_file_source.hpp b/include/mbgl/storage/default_file_source.hpp
index 8f88964acf..10a836094c 100644
--- a/include/mbgl/storage/default_file_source.hpp
+++ b/include/mbgl/storage/default_file_source.hpp
@@ -174,6 +174,15 @@ public:
      */
     void put(const Resource&, const Response&);
 
+    /*
+     * Delete existing database and re-initialize.
+     *
+     * 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 resetCache(std::function<void (std::exception_ptr)>);
+
     // For testing only.
     void setOnlineStatus(bool);
 
diff --git a/platform/default/include/mbgl/storage/offline_database.hpp b/platform/default/include/mbgl/storage/offline_database.hpp
index 6414affbbe..3ba15d5813 100644
--- a/platform/default/include/mbgl/storage/offline_database.hpp
+++ b/platform/default/include/mbgl/storage/offline_database.hpp
@@ -44,8 +44,7 @@ public:
     ~OfflineDatabase();
 
     void changePath(const std::string&);
-
-    void cleanup();
+    std::exception_ptr resetCache();
 
     optional<Response> get(const Resource&);
 
@@ -91,6 +90,7 @@ private:
     void migrateToVersion5();
     void migrateToVersion3();
     void migrateToVersion6();
+    void cleanup();
 
     mapbox::sqlite::Statement& getStatement(const char *);
 
diff --git a/platform/default/src/mbgl/storage/default_file_source.cpp b/platform/default/src/mbgl/storage/default_file_source.cpp
index 1ccf999109..08fbbff9a0 100644
--- a/platform/default/src/mbgl/storage/default_file_source.cpp
+++ b/platform/default/src/mbgl/storage/default_file_source.cpp
@@ -177,6 +177,10 @@ public:
         offlineDatabase->put(resource, response);
     }
 
+    void resetCache(std::function<void (std::exception_ptr)> callback) {
+        callback(offlineDatabase->resetCache());
+    }
+
 private:
     expected<OfflineDownload*, std::exception_ptr> getDownload(int64_t regionID) {
         auto it = downloads.find(regionID);
@@ -316,6 +320,10 @@ void DefaultFileSource::put(const Resource& resource, const Response& response)
     impl->actor().invoke(&Impl::put, resource, response);
 }
 
+void DefaultFileSource::resetCache(std::function<void (std::exception_ptr)> callback) {
+    impl->actor().invoke(&Impl::resetCache, callback);
+}
+
 // For testing only:
 
 void DefaultFileSource::setOnlineStatus(const bool status) {
diff --git a/platform/default/src/mbgl/storage/offline_database.cpp b/platform/default/src/mbgl/storage/offline_database.cpp
index 752f5ac20a..1639c4484c 100644
--- a/platform/default/src/mbgl/storage/offline_database.cpp
+++ b/platform/default/src/mbgl/storage/offline_database.cpp
@@ -1136,4 +1136,12 @@ bool OfflineDatabase::exceedsOfflineMapboxTileCountLimit(const Resource& resourc
         && offlineMapboxTileCountLimitExceeded();
 }
 
+std::exception_ptr OfflineDatabase::resetCache() try {
+    removeExisting();
+    initialize();
+    return nullptr;
+} catch (...) {
+    return std::current_exception();
+}
+
 } // namespace mbgl
diff --git a/platform/glfw/glfw_view.cpp b/platform/glfw/glfw_view.cpp
index 2772ed0773..fe956d8a68 100644
--- a/platform/glfw/glfw_view.cpp
+++ b/platform/glfw/glfw_view.cpp
@@ -124,6 +124,7 @@ GLFWView::GLFWView(bool fullscreen_, bool benchmark_)
     printf("- Press `O` to toggle online connectivity\n");
     printf("- Press `Z` to cycle through north orientations\n");
     printf("- Prezz `X` to cycle through the viewport modes\n");
+    printf("- Press `I` to Delete existing database and re-initialize\n");
     printf("- Press `A` to cycle through Mapbox offices in the world + dateline monument\n");
     printf("- Press `B` to cycle through the color, stencil, and depth buffer\n");
     printf("- Press `D` to cycle through camera bounds: inside, crossing IDL at left, crossing IDL at right, and disabled\n");
@@ -221,6 +222,9 @@ void GLFWView::onKey(GLFWwindow *window, int key, int /*scancode*/, int action,
         case GLFW_KEY_C:
             view->clearAnnotations();
             break;
+        case GLFW_KEY_I:
+            view->resetCacheCallback();
+            break;
         case GLFW_KEY_K:
             view->addRandomCustomPointAnnotations(1);
             break;
diff --git a/platform/glfw/glfw_view.hpp b/platform/glfw/glfw_view.hpp
index 9b580f80cc..1957970b85 100644
--- a/platform/glfw/glfw_view.hpp
+++ b/platform/glfw/glfw_view.hpp
@@ -40,6 +40,10 @@ public:
         onlineStatusCallback = callback;
     }
 
+    void setResetCacheCallback(std::function<void()> callback) {
+        resetCacheCallback = callback;
+    };
+
     void setShouldClose();
 
     void setWindowTitle(const std::string&);
@@ -120,6 +124,7 @@ private:
     std::function<void()> changeStyleCallback;
     std::function<void()> pauseResumeCallback;
     std::function<void()> onlineStatusCallback;
+    std::function<void()> resetCacheCallback;
     std::function<void(mbgl::Map*)> animateRouteCallback;
 
     mbgl::util::RunLoop runLoop;
diff --git a/platform/glfw/main.cpp b/platform/glfw/main.cpp
index 0a4ace6a19..4e631ec895 100644
--- a/platform/glfw/main.cpp
+++ b/platform/glfw/main.cpp
@@ -6,6 +6,7 @@
 #include <mbgl/util/logging.hpp>
 #include <mbgl/util/platform.hpp>
 #include <mbgl/util/default_thread_pool.hpp>
+#include <mbgl/util/string.hpp>
 #include <mbgl/storage/default_file_source.hpp>
 #include <mbgl/style/style.hpp>
 #include <mbgl/renderer/renderer.hpp>
@@ -159,6 +160,14 @@ int main(int argc, char *argv[]) {
         isPaused = !isPaused;
     });
 
+    view->setResetCacheCallback([fileSource] () {
+        fileSource->resetCache([](std::exception_ptr ex) {
+            if (ex) {
+                mbgl::Log::Error(mbgl::Event::Database, "Failed to reset cache:: %s", mbgl::util::toString(ex).c_str());
+            }
+        });
+    });
+
     // Load style
     if (style.empty()) {
         const char *url = getenv("MAPBOX_STYLE_URL");