[core] Interface and implementation for offline

1 files changed, 62 insertions, 0 deletions

diff --git a/platform/default/mbgl/storage/offline_download.hpp b/platform/default/mbgl/storage/offline_download.hpp
new file mode 100644
index 0000000000..4200020487
--- /dev/null
+++ b/platform/default/mbgl/storage/offline_download.hpp
@@ -0,0 +1,62 @@
+    #pragma once
+
+#include <mbgl/storage/offline.hpp>
+#include <mbgl/style/types.hpp>
+
+#include <list>
+#include <set>
+#include <memory>
+
+namespace mbgl {
+
+class OfflineDatabase;
+class FileSource;
+class FileRequest;
+class Resource;
+class Response;
+class SourceInfo;
+class StyleParser;
+class Source;
+
+/**
+ * Coordinates the request and storage of all resources for an offline region.
+
+ * @private
+ */
+class OfflineDownload {
+public:
+    OfflineDownload(int64_t id, OfflineRegionDefinition&&, OfflineDatabase& offline, FileSource& online);
+    ~OfflineDownload();
+
+    void setObserver(std::unique_ptr<OfflineRegionObserver>);
+    void setState(OfflineRegionDownloadState);
+
+    OfflineRegionStatus getStatus() const;
+
+private:
+    void activateDownload();
+    void deactivateDownload();
+
+    std::vector<Resource> spriteResources(const StyleParser&) const;
+    std::vector<Resource> glyphResources(const StyleParser&) const;
+    std::vector<Resource> tileResources(SourceType, uint16_t, const SourceInfo&) const;
+
+    /*
+     * Ensure that the resource is stored in the database, requesting it if necessary.
+     * While the request is in progress, it is recorded in `requests`. If the download
+     * is deactivated, all in progress requests are cancelled.
+     */
+    void ensureResource(const Resource&, std::function<void (Response)> = {});
+    void ensureTiles(SourceType, uint16_t, const SourceInfo&);
+
+    int64_t id;
+    OfflineRegionDefinition definition;
+    OfflineDatabase& offlineDatabase;
+    FileSource& onlineFileSource;
+    OfflineRegionStatus status;
+    std::unique_ptr<OfflineRegionObserver> observer;
+    std::list<std::unique_ptr<FileRequest>> requests;
+    std::set<std::string> requiredSourceURLs;
+};
+
+} // namespace mbgl