Server pushing media at runtime (#9961)

src/client/client.cpp

@@ -670,11 +670,9 @@ void Client::step(float dtime)
 	}
 }
 
-bool Client::loadMedia(const std::string &data, const std::string &filename)
+bool Client::loadMedia(const std::string &data, const std::string &filename,
+	bool from_media_push)
 {
-	// Silly irrlicht's const-incorrectness
-	Buffer<char> data_rw(data.c_str(), data.size());
-
 	std::string name;
 
 	const char *image_ext[] = {
@@ -690,6 +688,9 @@ bool Client::loadMedia(const std::string &data, const std::string &filename)
 		io::IFileSystem *irrfs = RenderingEngine::get_filesystem();
 		video::IVideoDriver *vdrv = RenderingEngine::get_video_driver();
 
+		// Silly irrlicht's const-incorrectness
+		Buffer<char> data_rw(data.c_str(), data.size());
+
 		// Create an irrlicht memory file
 		io::IReadFile *rfile = irrfs->createMemoryReadFile(
 				*data_rw, data_rw.getSize(), "_tempreadfile");
@@ -727,7 +728,6 @@ bool Client::loadMedia(const std::string &data, const std::string &filename)
 		".x", ".b3d", ".md2", ".obj",
 		NULL
 	};
-
 	name = removeStringEnd(filename, model_ext);
 	if (!name.empty()) {
 		verbosestream<<"Client: Storing model into memory: "
@@ -744,6 +744,8 @@ bool Client::loadMedia(const std::string &data, const std::string &filename)
 	};
 	name = removeStringEnd(filename, translate_ext);
 	if (!name.empty()) {
+		if (from_media_push)
+			return false;
 		TRACESTREAM(<< "Client: Loading translation: "
 				<< "\"" << filename << "\"" << std::endl);
 		g_client_translations->loadTranslation(data);

src/client/client.h

@@ -222,6 +222,7 @@ public:
 	void handleCommand_FormspecPrepend(NetworkPacket *pkt);
 	void handleCommand_CSMRestrictionFlags(NetworkPacket *pkt);
 	void handleCommand_PlayerSpeed(NetworkPacket *pkt);
+	void handleCommand_MediaPush(NetworkPacket *pkt);
 
 	void ProcessData(NetworkPacket *pkt);
 
@@ -376,7 +377,8 @@ public:
 
 	// The following set of functions is used by ClientMediaDownloader
 	// Insert a media file appropriately into the appropriate manager
-	bool loadMedia(const std::string &data, const std::string &filename);
+	bool loadMedia(const std::string &data, const std::string &filename,
+		bool from_media_push = false);
 	// Send a request for conventional media transfer
 	void request_media(const std::vector<std::string> &file_requests);
 
@@ -488,6 +490,7 @@ private:
 	Camera *m_camera = nullptr;
 	Minimap *m_minimap = nullptr;
 	bool m_minimap_disabled_by_server = false;
+
 	// Server serialization version
 	u8 m_server_ser_ver;
 
@@ -529,7 +532,6 @@ private:
 	AuthMechanism m_chosen_auth_mech;
 	void *m_auth_data = nullptr;
 
-
 	bool m_access_denied = false;
 	bool m_access_denied_reconnect = false;
 	std::string m_access_denied_reason = "";
@@ -538,7 +540,10 @@ private:
 	bool m_nodedef_received = false;
 	bool m_activeobjects_received = false;
 	bool m_mods_loaded = false;
+
 	ClientMediaDownloader *m_media_downloader;
+	// Set of media filenames pushed by server at runtime
+	std::unordered_set<std::string> m_media_pushed_files;
 
 	// time_of_day speed approximation for old protocol
 	bool m_time_of_day_set = false;

src/client/clientmedia.cpp

@@ -35,6 +35,15 @@ static std::string getMediaCacheDir()
 	return porting::path_cache + DIR_DELIM + "media";
 }
 
+bool clientMediaUpdateCache(const std::string &raw_hash, const std::string &filedata)
+{
+	FileCache media_cache(getMediaCacheDir());
+	std::string sha1_hex = hex_encode(raw_hash);
+	if (!media_cache.exists(sha1_hex))
+		return media_cache.update(sha1_hex, filedata);
+	return true;
+}
+
 /*
 	ClientMediaDownloader
 */
@@ -559,7 +568,6 @@ bool ClientMediaDownloader::checkAndLoad(
 	return true;
 }
 
-
 /*
 	Minetest Hashset File Format
 

src/client/clientmedia.h

@@ -33,6 +33,11 @@ struct HTTPFetchResult;
 #define MTHASHSET_FILE_SIGNATURE 0x4d544853 // 'MTHS'
 #define MTHASHSET_FILE_NAME "index.mth"
 
+// Store file into media cache (unless it exists already)
+// Validating the hash is responsibility of the caller
+bool clientMediaUpdateCache(const std::string &raw_hash,
+	const std::string &filedata);
+
 class ClientMediaDownloader
 {
 public:

src/client/filecache.cpp

@@ -82,8 +82,16 @@ bool FileCache::update(const std::string &name, const std::string &data)
 	std::string path = m_dir + DIR_DELIM + name;
 	return updateByPath(path, data);
 }
+
 bool FileCache::load(const std::string &name, std::ostream &os)
 {
 	std::string path = m_dir + DIR_DELIM + name;
 	return loadByPath(path, os);
 }
+
+bool FileCache::exists(const std::string &name)
+{
+	std::string path = m_dir + DIR_DELIM + name;
+	std::ifstream fis(path.c_str(), std::ios_base::binary);
+	return fis.good();
+}

src/client/filecache.h

@@ -33,6 +33,7 @@ public:
 
 	bool update(const std::string &name, const std::string &data);
 	bool load(const std::string &name, std::ostream &os);
+	bool exists(const std::string &name);
 
 private:
 	std::string m_dir;