//////////////////////////////////////////////////////////////////////////////// /// @brief Class to get and cache information about the cluster state /// /// @file ClusterInfo.h /// /// DISCLAIMER /// /// Copyright 2010-2013 triagens GmbH, Cologne, Germany /// /// Licensed under the Apache License, Version 2.0 (the "License"); /// you may not use this file except in compliance with the License. /// You may obtain a copy of the License at /// /// http://www.apache.org/licenses/LICENSE-2.0 /// /// Unless required by applicable law or agreed to in writing, software /// distributed under the License is distributed on an "AS IS" BASIS, /// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. /// See the License for the specific language governing permissions and /// limitations under the License. /// /// Copyright holder is triAGENS GmbH, Cologne, Germany /// /// @author Max Neunhoeffer /// @author Copyright 2013, triagens GmbH, Cologne, Germany //////////////////////////////////////////////////////////////////////////////// #ifndef TRIAGENS_CLUSTER_STATE_H #define TRIAGENS_CLUSTER_STATE_H 1 #include "Basics/Common.h" #include "Cluster/AgencyComm.h" #ifdef __cplusplus extern "C" { #endif namespace triagens { namespace arango { // ----------------------------------------------------------------------------- // --SECTION-- some types for ClusterInfo // ----------------------------------------------------------------------------- typedef string ServerID; // ID of a server typedef string DatabaseID; // ID/name of a database typedef string CollectionID; // ID of a collection typedef string ShardID; // ID of a shard // ----------------------------------------------------------------------------- // --SECTION-- class CollectionInfo // ----------------------------------------------------------------------------- struct CollectionInfo { enum Status { LOADED = 1, UNLOADED = 2 }; enum Type { NORMAL = 1, EDGES = 2 }; DatabaseID database; string id; string name; Status status; Type type; vector shards; CollectionInfo () : id(""), name(""), status(LOADED), type(NORMAL) { } ~CollectionInfo () { } }; // ----------------------------------------------------------------------------- // --SECTION-- class ClusterInfo // ----------------------------------------------------------------------------- class ClusterInfo { // ----------------------------------------------------------------------------- // --SECTION-- constructors and destructors // ----------------------------------------------------------------------------- //////////////////////////////////////////////////////////////////////////////// /// @brief initialises library /// /// We are a singleton class, therefore nobody is allowed to create /// new instances or copy them, except we ourselves. //////////////////////////////////////////////////////////////////////////////// ClusterInfo (); ClusterInfo (ClusterInfo const&); // not implemented void operator= (ClusterInfo const&); // not implemented static ClusterInfo* _theinstance; public: //////////////////////////////////////////////////////////////////////////////// /// @brief shuts down library //////////////////////////////////////////////////////////////////////////////// ~ClusterInfo (); // ----------------------------------------------------------------------------- // --SECTION-- public methods // ----------------------------------------------------------------------------- //////////////////////////////////////////////////////////////////////////////// /// @brief get the unique instance //////////////////////////////////////////////////////////////////////////////// static ClusterInfo* instance (); //////////////////////////////////////////////////////////////////////////////// /// @brief initialise function to call once when still single-threaded //////////////////////////////////////////////////////////////////////////////// static void initialise (); //////////////////////////////////////////////////////////////////////////////// /// @brief cleanup function to call once when shutting down //////////////////////////////////////////////////////////////////////////////// static void cleanup () { delete _theinstance; _theinstance = 0; } //////////////////////////////////////////////////////////////////////////////// /// @brief find the endpoint of a server from its ID. /// /// If it is not found in the cache, the cache is reloaded once, if /// it is still not there an empty string is returned as an error. //////////////////////////////////////////////////////////////////////////////// string getServerEndpoint(ServerID const& serverID); //////////////////////////////////////////////////////////////////////////////// /// @brief (re-)load the information about servers from the agency /// /// Usually one does not have to call this directly. //////////////////////////////////////////////////////////////////////////////// void loadServerInformation (); //////////////////////////////////////////////////////////////////////////////// /// @brief find the server who is responsible for a shard /// /// If it is not found in the cache, the cache is reloaded once, if /// it is still not there an empty string is returned as an error. //////////////////////////////////////////////////////////////////////////////// ServerID getResponsibleServer(ShardID const& shardID); //////////////////////////////////////////////////////////////////////////////// /// @brief (re-)load the information about shards from the agency /// /// Usually one does not have to call this directly. //////////////////////////////////////////////////////////////////////////////// void loadShardInformation (); //////////////////////////////////////////////////////////////////////////////// /// @brief ask whether a cluster database exists //////////////////////////////////////////////////////////////////////////////// bool doesDatabaseExist (DatabaseID const& databaseID); //////////////////////////////////////////////////////////////////////////////// /// @brief (re-)load the information about databases from the agency /// /// Usually one does not have to call this directly. //////////////////////////////////////////////////////////////////////////////// void loadDatabaseInformation (); //////////////////////////////////////////////////////////////////////////////// /// @brief ask about a collection /// /// If it is not found in the cache, the cache is reloaded once, if /// it is still not there an empty 0 pointer is returned. The caller /// must not delete the pointer. //////////////////////////////////////////////////////////////////////////////// CollectionInfo const* getCollectionInfo( DatabaseID const& databaseID, CollectionID const& collectionID); //////////////////////////////////////////////////////////////////////////////// /// @brief (re-)load the information about collections from the agency /// /// Usually one does not have to call this directly. //////////////////////////////////////////////////////////////////////////////// void loadCollectionsInformation (); //////////////////////////////////////////////////////////////////////////////// /// @brief get a number of cluster-wide unique IDs, returns the first /// one and guarantees that are reserved for the caller. //////////////////////////////////////////////////////////////////////////////// uint64_t fetchIDs (uint64_t number); private: AgencyComm _agency; // Cached data from the agency, we reload whenever necessary: map serverAddresses; // from Current/ServersRegistered map shards; // from Current/ShardLocation map collections; // from Current/Collections/ triagens::basics::ReadWriteLock lock; }; } // end namespace arango } // end namespace triagens #ifdef __cplusplus } #endif #endif // Local Variables: // mode: outline-minor // outline-regexp: "^\\(/// @brief\\|/// {@inheritDoc}\\|/// @addtogroup\\|// --SECTION--\\|/// @\\}\\)" // End: