citus/src/include/distributed/connection_cache.h

52 lines
1.7 KiB
C

/*-------------------------------------------------------------------------
*
* connection_cache.h
*
* Declarations for public functions and types related to connection hash
* functionality.
*
* Copyright (c) 2014-2016, Citus Data, Inc.
*
*-------------------------------------------------------------------------
*/
#ifndef CONNECTION_CACHE_H
#define CONNECTION_CACHE_H
#include "c.h"
#include "libpq-fe.h"
#include "utils/hsearch.h"
#include "distributed/connection_management.h"
/*
* NodeConnectionKey acts as the key to index into the (process-local) hash
* keeping track of open connections. Node name and port are sufficient.
*/
typedef struct NodeConnectionKey
{
char nodeName[MAX_NODE_LENGTH + 1]; /* hostname of host to connect to */
int32 nodePort; /* port of host to connect to */
char nodeUser[NAMEDATALEN + 1]; /* user name to connect as */
} NodeConnectionKey;
/* NodeConnectionEntry keeps track of connections themselves. */
typedef struct NodeConnectionEntry
{
NodeConnectionKey cacheKey; /* hash entry key */
MultiConnection *connection; /* connection to remote server, if any */
} NodeConnectionEntry;
/* function declarations for obtaining and using a connection */
extern PGconn * GetOrEstablishConnection(char *nodeName, int32 nodePort);
extern void BuildKeyForConnection(PGconn *connection, NodeConnectionKey *connectionKey);
extern void WarnRemoteError(PGconn *connection, PGresult *result);
extern void ReraiseRemoteError(PGconn *connection, PGresult *result);
extern PGconn * ConnectToNode(char *nodeName, int nodePort, char *nodeUser);
extern char * ConnectionGetOptionValue(PGconn *connection, char *optionKeyword);
#endif /* CONNECTION_CACHE_H */