Dynamic_Add_Media v2 (#11550)

src/client/clientmedia.h

@@ -21,6 +21,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include "irrlichttypes.h"
 #include "filecache.h"
+#include "util/basic_macros.h"
 #include <ostream>
 #include <map>
 #include <set>
@@ -38,7 +39,62 @@ struct HTTPFetchResult;
 bool clientMediaUpdateCache(const std::string &raw_hash,
 	const std::string &filedata);
 
-class ClientMediaDownloader
+// more of a base class than an interface but this name was most convenient...
+class IClientMediaDownloader
+{
+public:
+	DISABLE_CLASS_COPY(IClientMediaDownloader)
+
+	virtual bool isStarted() const = 0;
+
+	// If this returns true, the downloader is done and can be deleted
+	virtual bool isDone() const = 0;
+
+	// Add a file to the list of required file (but don't fetch it yet)
+	virtual void addFile(const std::string &name, const std::string &sha1) = 0;
+
+	// Add a remote server to the list; ignored if not built with cURL
+	virtual void addRemoteServer(const std::string &baseurl) = 0;
+
+	// Steps the media downloader:
+	// - May load media into client by calling client->loadMedia()
+	// - May check media cache for files
+	// - May add files to media cache
+	// - May start remote transfers by calling httpfetch_async
+	// - May check for completion of current remote transfers
+	// - May start conventional transfers by calling client->request_media()
+	// - May inform server that all media has been loaded
+	//   by calling client->received_media()
+	// After step has been called once, don't call addFile/addRemoteServer.
+	virtual void step(Client *client) = 0;
+
+	// Must be called for each file received through TOCLIENT_MEDIA
+	// returns true if this file belongs to this downloader
+	virtual bool conventionalTransferDone(const std::string &name,
+			const std::string &data, Client *client) = 0;
+
+protected:
+	IClientMediaDownloader();
+	virtual ~IClientMediaDownloader() = default;
+
+	// Forwards the call to the appropriate Client method
+	virtual bool loadMedia(Client *client, const std::string &data,
+		const std::string &name) = 0;
+
+	void createCacheDirs();
+
+	bool tryLoadFromCache(const std::string &name, const std::string &sha1,
+			Client *client);
+
+	bool checkAndLoad(const std::string &name, const std::string &sha1,
+			const std::string &data, bool is_from_cache, Client *client);
+
+	// Filesystem-based media cache
+	FileCache m_media_cache;
+	bool m_write_to_cache;
+};
+
+class ClientMediaDownloader : public IClientMediaDownloader
 {
 public:
 	ClientMediaDownloader();
@@ -52,39 +108,29 @@ public:
 		return 0.0f;
 	}
 
-	bool isStarted() const {
+	bool isStarted() const override {
 		return m_initial_step_done;
 	}
 
-	// If this returns true, the downloader is done and can be deleted
-	bool isDone() const {
+	bool isDone() const override {
 		return m_initial_step_done &&
 			m_uncached_received_count == m_uncached_count;
 	}
 
-	// Add a file to the list of required file (but don't fetch it yet)
-	void addFile(const std::string &name, const std::string &sha1);
+	void addFile(const std::string &name, const std::string &sha1) override;
 
-	// Add a remote server to the list; ignored if not built with cURL
-	void addRemoteServer(const std::string &baseurl);
+	void addRemoteServer(const std::string &baseurl) override;
 
-	// Steps the media downloader:
-	// - May load media into client by calling client->loadMedia()
-	// - May check media cache for files
-	// - May add files to media cache
-	// - May start remote transfers by calling httpfetch_async
-	// - May check for completion of current remote transfers
-	// - May start conventional transfers by calling client->request_media()
-	// - May inform server that all media has been loaded
-	//   by calling client->received_media()
-	// After step has been called once, don't call addFile/addRemoteServer.
-	void step(Client *client);
+	void step(Client *client) override;
 
-	// Must be called for each file received through TOCLIENT_MEDIA
-	void conventionalTransferDone(
+	bool conventionalTransferDone(
 			const std::string &name,
 			const std::string &data,
-			Client *client);
+			Client *client) override;
+
+protected:
+	bool loadMedia(Client *client, const std::string &data,
+			const std::string &name) override;
 
 private:
 	struct FileStatus {
@@ -107,13 +153,9 @@ private:
 	void startRemoteMediaTransfers();
 	void startConventionalTransfers(Client *client);
 
-	bool checkAndLoad(const std::string &name, const std::string &sha1,
-			const std::string &data, bool is_from_cache,
-			Client *client);
-
-	std::string serializeRequiredHashSet();
 	static void deSerializeHashSet(const std::string &data,
 			std::set<std::string> &result);
+	std::string serializeRequiredHashSet();
 
 	// Maps filename to file status
 	std::map<std::string, FileStatus*> m_files;
@@ -121,9 +163,6 @@ private:
 	// Array of remote media servers
 	std::vector<RemoteServerStatus*> m_remotes;
 
-	// Filesystem-based media cache
-	FileCache m_media_cache;
-
 	// Has an attempt been made to load media files from the file cache?
 	// Have hash sets been requested from remote servers?
 	bool m_initial_step_done = false;
@@ -149,3 +188,63 @@ private:
 	std::string m_name_bound = "";
 
 };
+
+// A media downloader that only downloads a single file.
+// It does/doesn't do several things the normal downloader does:
+// - won't fetch hash sets from remote servers
+// - will mark loaded media as coming from file push
+// - writing to file cache is optional
+class SingleMediaDownloader : public IClientMediaDownloader
+{
+public:
+	SingleMediaDownloader(bool write_to_cache);
+	~SingleMediaDownloader();
+
+	bool isStarted() const override {
+		return m_stage > STAGE_INIT;
+	}
+
+	bool isDone() const override {
+		return m_stage >= STAGE_DONE;
+	}
+
+	void addFile(const std::string &name, const std::string &sha1) override;
+
+	void addRemoteServer(const std::string &baseurl) override;
+
+	void step(Client *client) override;
+
+	bool conventionalTransferDone(const std::string &name,
+			const std::string &data, Client *client) override;
+
+protected:
+	bool loadMedia(Client *client, const std::string &data,
+			const std::string &name) override;
+
+private:
+	void initialStep(Client *client);
+	void remoteMediaReceived(const HTTPFetchResult &fetch_result, Client *client);
+	void startRemoteMediaTransfer();
+	void startConventionalTransfer(Client *client);
+
+	enum Stage {
+		STAGE_INIT,
+		STAGE_CACHE_CHECKED, // we have tried to load the file from cache
+		STAGE_DONE
+	};
+
+	// Information about the one file we want to fetch
+	std::string m_file_name;
+	std::string m_file_sha1;
+	s32 m_current_remote;
+
+	// Array of remote media servers
+	std::vector<std::string> m_remotes;
+
+	enum Stage m_stage = STAGE_INIT;
+
+	// Status of remote transfers
+	unsigned long m_httpfetch_caller;
+	unsigned long m_httpfetch_next_id = 0;
+
+};