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arangodb/arangod/Cluster/ClusterInfo.h

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C++

////////////////////////////////////////////////////////////////////////////////
/// @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 Jan Steemann
/// @author Copyright 2013, triagens GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#ifndef TRIAGENS_CLUSTER_CLUSTER_INFO_H
#define TRIAGENS_CLUSTER_CLUSTER_INFO_H 1
#include "Basics/Common.h"
#include "Cluster/AgencyComm.h"
#include "VocBase/collection.h"
#include "VocBase/voc-types.h"
#include "VocBase/vocbase.h"
#ifdef __cplusplus
extern "C" {
struct TRI_json_s;
struct TRI_memory_zone_s;
#endif
namespace triagens {
namespace arango {
class ClusterInfo;
// -----------------------------------------------------------------------------
// --SECTION-- some types for ClusterInfo
// -----------------------------------------------------------------------------
typedef std::string ServerID; // ID of a server
typedef std::string DatabaseID; // ID/name of a database
typedef std::string CollectionID; // ID of a collection
typedef std::string ShardID; // ID of a shard
// -----------------------------------------------------------------------------
// --SECTION-- class CollectionInfo
// -----------------------------------------------------------------------------
class CollectionInfo {
friend class ClusterInfo;
// -----------------------------------------------------------------------------
// --SECTION-- constructors / destructors
// -----------------------------------------------------------------------------
public:
CollectionInfo ();
CollectionInfo (std::string const&);
CollectionInfo (CollectionInfo const&);
CollectionInfo& operator= (CollectionInfo const&);
~CollectionInfo ();
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
public:
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the collection id
////////////////////////////////////////////////////////////////////////////////
TRI_voc_cid_t cid () const {
return _id;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the collection name
////////////////////////////////////////////////////////////////////////////////
std::string name () const {
return _name;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the collection type
////////////////////////////////////////////////////////////////////////////////
TRI_col_type_e type () const {
return _type;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the collection status
////////////////////////////////////////////////////////////////////////////////
TRI_vocbase_col_status_e status () const {
return _status;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the collection status
////////////////////////////////////////////////////////////////////////////////
std::string statusString () const {
return TRI_GetStatusStringCollectionVocBase(_status);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the properties
////////////////////////////////////////////////////////////////////////////////
TRI_col_info_t properties () const;
////////////////////////////////////////////////////////////////////////////////
/// @brief TODO: returns the indexes
////////////////////////////////////////////////////////////////////////////////
/*
std::vector<std::string> indexes () const {
return _indexes;
}
*/
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the shard keys
////////////////////////////////////////////////////////////////////////////////
std::vector<std::string> shardKeys () const {
return _shardKeys;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief returns the shard ids
////////////////////////////////////////////////////////////////////////////////
std::map<std::string, std::string> shardIds () const {
return _shardIds;
}
// -----------------------------------------------------------------------------
// --SECTION-- private methods
// -----------------------------------------------------------------------------
private:
////////////////////////////////////////////////////////////////////////////////
/// @brief invalidates a collection info object
////////////////////////////////////////////////////////////////////////////////
void invalidate ();
////////////////////////////////////////////////////////////////////////////////
/// @brief populate object properties from the JSON given
////////////////////////////////////////////////////////////////////////////////
bool createFromJson (struct TRI_json_s const*);
////////////////////////////////////////////////////////////////////////////////
/// @brief create a JSON string from the object
////////////////////////////////////////////////////////////////////////////////
struct TRI_json_s* toJson (struct TRI_memory_zone_s*);
// -----------------------------------------------------------------------------
// --SECTION-- private variables
// -----------------------------------------------------------------------------
TRI_voc_cid_t _id;
std::string _name;
TRI_col_type_e _type;
TRI_vocbase_col_status_e _status;
TRI_voc_size_t _maximalSize;
bool _deleted;
bool _doCompact;
bool _isSystem;
bool _isVolatile;
bool _waitForSync;
TRI_json_t* _keyOptions;
// TODO: indexes
std::vector<std::string> _shardKeys;
std::map<std::string, std::string> _shardIds;
};
// -----------------------------------------------------------------------------
// --SECTION-- class ClusterInfo
// -----------------------------------------------------------------------------
// -----------------------------------------------------------------------------
// --SECTION-- typedefs
// -----------------------------------------------------------------------------
class ClusterInfo {
private:
typedef std::map<CollectionID, CollectionInfo> DatabaseCollections;
typedef std::map<DatabaseID, DatabaseCollections> AllCollections;
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
private:
////////////////////////////////////////////////////////////////////////////////
/// @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
////////////////////////////////////////////////////////////////////////////////
/// @brief shuts down library
////////////////////////////////////////////////////////////////////////////////
public:
~ClusterInfo ();
// -----------------------------------------------------------------------------
// --SECTION-- public static methods
// -----------------------------------------------------------------------------
public:
////////////////////////////////////////////////////////////////////////////////
/// @brief get the unique instance
////////////////////////////////////////////////////////////////////////////////
static ClusterInfo* instance ();
////////////////////////////////////////////////////////////////////////////////
/// @brief cleanup function to call once when shutting down
////////////////////////////////////////////////////////////////////////////////
static void cleanup () {
delete _theinstance;
_theinstance = 0;
}
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
public:
////////////////////////////////////////////////////////////////////////////////
/// @brief get a number of cluster-wide unique IDs, returns the first
/// one and guarantees that <number> are reserved for the caller.
////////////////////////////////////////////////////////////////////////////////
uint64_t uniqid (uint64_t = 1);
////////////////////////////////////////////////////////////////////////////////
/// @brief flush the caches (used for testing only)
////////////////////////////////////////////////////////////////////////////////
void flush ();
////////////////////////////////////////////////////////////////////////////////
/// @brief ask whether a cluster database exists
////////////////////////////////////////////////////////////////////////////////
bool doesDatabaseExist (DatabaseID const& databaseID);
////////////////////////////////////////////////////////////////////////////////
/// @brief get list of databases in the cluster
////////////////////////////////////////////////////////////////////////////////
vector<DatabaseID> listDatabases ();
////////////////////////////////////////////////////////////////////////////////
/// @brief (re-)load the information about collections from the agency
/// Usually one does not have to call this directly.
////////////////////////////////////////////////////////////////////////////////
void loadCurrentCollections ();
////////////////////////////////////////////////////////////////////////////////
/// @brief (re-)load the information about planned databases
/// Usually one does not have to call this directly.
////////////////////////////////////////////////////////////////////////////////
void loadPlannedDatabases ();
////////////////////////////////////////////////////////////////////////////////
/// @brief ask about a collection
/// If it is not found in the cache, the cache is reloaded once.
////////////////////////////////////////////////////////////////////////////////
CollectionInfo getCollection (DatabaseID const&,
CollectionID const&);
////////////////////////////////////////////////////////////////////////////////
/// @brief get properties of a collection
////////////////////////////////////////////////////////////////////////////////
TRI_col_info_t getCollectionProperties (CollectionInfo const&);
////////////////////////////////////////////////////////////////////////////////
/// @brief get properties of a collection
////////////////////////////////////////////////////////////////////////////////
TRI_col_info_t getCollectionProperties (DatabaseID const&,
CollectionID const&);
////////////////////////////////////////////////////////////////////////////////
/// @brief ask about all collections
////////////////////////////////////////////////////////////////////////////////
const std::vector<CollectionInfo> getCollections (DatabaseID const&);
////////////////////////////////////////////////////////////////////////////////
/// @brief (re-)load the information about all DBservers from the agency
/// Usually one does not have to call this directly.
////////////////////////////////////////////////////////////////////////////////
void loadCurrentDBServers ();
////////////////////////////////////////////////////////////////////////////////
/// @brief return a list of all DBServers in the cluster that have
/// currently registered
////////////////////////////////////////////////////////////////////////////////
std::vector<ServerID> getCurrentDBServers ();
////////////////////////////////////////////////////////////////////////////////
/// @brief (re-)load the information about servers from the agency
/// Usually one does not have to call this directly.
////////////////////////////////////////////////////////////////////////////////
void loadServers ();
////////////////////////////////////////////////////////////////////////////////
/// @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.
////////////////////////////////////////////////////////////////////////////////
std::string getServerEndpoint (ServerID const&);
////////////////////////////////////////////////////////////////////////////////
/// @brief lookup the server's endpoint by scanning Target/MapIDToEnpdoint for
/// our id
////////////////////////////////////////////////////////////////////////////////
std::string getTargetServerEndpoint (ServerID const&);
////////////////////////////////////////////////////////////////////////////////
/// @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&);
// -----------------------------------------------------------------------------
// --SECTION-- private variables
// -----------------------------------------------------------------------------
private:
AgencyComm _agency;
triagens::basics::ReadWriteLock _lock;
////////////////////////////////////////////////////////////////////////////////
/// @brief uniqid sequence
////////////////////////////////////////////////////////////////////////////////
struct {
uint64_t _currentValue;
uint64_t _upperValue;
}
_uniqid;
// Cached data from the agency, we reload whenever necessary:
std::map<DatabaseID, struct TRI_json_s*> _plannedDatabases; // from Plan/Databases
AllCollections _collections; // from Current/Collections/
bool _collectionsValid;
std::map<ServerID, std::string> _servers; // from Current/ServersRegistered
bool _serversValid;
std::map<ServerID, ServerID> _DBServers; // from Current/DBServers
bool _DBServersValid;
std::map<ShardID, ServerID> _shardIds; // from Current/ShardLocation
// -----------------------------------------------------------------------------
// --SECTION-- private static variables
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief the sole instance
////////////////////////////////////////////////////////////////////////////////
static ClusterInfo* _theinstance;
////////////////////////////////////////////////////////////////////////////////
/// @brief how big a batch is for unique ids
////////////////////////////////////////////////////////////////////////////////
static const uint64_t MinIdsPerBatch = 100;
};
} // end namespace arango
} // end namespace triagens
#ifdef __cplusplus
}
#endif
#endif
// Local Variables:
// mode: outline-minor
// outline-regexp: "^\\(/// @brief\\|/// {@inheritDoc}\\|/// @addtogroup\\|// --SECTION--\\|/// @\\}\\)"
// End: