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/*
* machine/m_common.c
*
* Functionalities common to all the platforms.
*
* Copyright (c) 2013 VMware, Inc. All Rights Reserved.
*/
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <unistd.h>
#include <libpq-fe.h>
#include "machine.h"
/* Query to fetch information about database activity */
#define QUERY_STAT_DB \
"SELECT datid, datname, numbackends, xact_commit, xact_rollback, \n" \
" blks_read, blks_hit, tup_returned, tup_fetched, \n" \
" tup_inserted, tup_updated, tup_deleted, conflicts \n" \
"FROM pg_stat_database;"
#define QUERY_DATA_DIRECTORY "SHOW data_directory;"
char *backendstatenames[] =
{
"", "idle", "active", "idltxn", "fast", "abort", "disabl", NULL
};
/* Store data directory to avoid unnecessary requests to server */
static char *data_directory = NULL;
/*
* Get database info via the above QUERY_STAT_DB info.
* Returns rate info on the various statistics by comparing current
* values with previous values.
*/
void
get_database_info(struct db_info *db_info, const char *values[])
{
struct timeval thistime;
double timediff;
int i;
int rows;
PGconn *pgconn;
PGresult *pgresult = NULL;
struct db_info cur_info;
static struct timeval lasttime;
static struct db_info last_db_info;
/* calculate the time difference since our last check */
gettimeofday(&thistime, 0);
if (lasttime.tv_sec)
timediff = ((thistime.tv_sec - lasttime.tv_sec) +
(thistime.tv_usec - lasttime.tv_usec) * 1e-6);
else
timediff = 0;
lasttime = thistime;
rows = 0;
pgconn = connect_to_db(values);
if (pgconn != NULL)
{
pgresult = PQexec(pgconn, QUERY_STAT_DB);
if (PQresultStatus(pgresult) == PGRES_TUPLES_OK)
rows = PQntuples(pgresult);
}
if (rows == 0)
{
/* Database probably stopped, clear current and last */
memset(&last_db_info, 0, sizeof(last_db_info));
}
memset(&cur_info, 0, sizeof(cur_info));
for (i = 0; i < rows; i++)
{
PQgetvalue(pgresult, i, 2);
/* Count all databases, even with no active backends */
cur_info.numDb++;
cur_info.numXact += atoi(PQgetvalue(pgresult, i, 3));
cur_info.numRollback += atoi(PQgetvalue(pgresult, i, 4));
cur_info.numBlockRead += atoi(PQgetvalue(pgresult, i, 5));
cur_info.numBlockHit += atoi(PQgetvalue(pgresult, i, 6));
cur_info.numTupleFetched += atoi(PQgetvalue(pgresult, i, 8));
cur_info.numTupleAltered += atoi(PQgetvalue(pgresult, i, 9)) +
atoi(PQgetvalue(pgresult, i, 10)) +
atoi(PQgetvalue(pgresult, i, 11));
cur_info.numConflict += atoi(PQgetvalue(pgresult, i, 12));
}
if (pgresult != NULL)
PQclear(pgresult);
PQfinish(pgconn);
if (timediff <= 0)
{
last_db_info = cur_info;
memset(db_info, 0, sizeof(*db_info));
return;
}
/* Compute the rate information */
db_info->numDb = cur_info.numDb;
db_info->numXact = (double)(cur_info.numXact - last_db_info.numXact) / timediff;
db_info->numRollback = (double)(cur_info.numRollback - last_db_info.numRollback) / timediff;
db_info->numBlockRead = (double)(cur_info.numBlockRead - last_db_info.numBlockRead) / timediff;
db_info->numBlockHit = (double)(cur_info.numBlockHit - last_db_info.numBlockHit) / timediff;
db_info->numTupleFetched = (double)(cur_info.numTupleFetched - last_db_info.numTupleFetched) / timediff;
db_info->numTupleAltered = (double)(cur_info.numTupleAltered - last_db_info.numTupleAltered) / timediff;
db_info->numConflict = (double)(cur_info.numConflict - last_db_info.numConflict) / timediff;
last_db_info = cur_info;
}
/*
* Obtain data directory of server if necessary. if this has already been
* queried to server, return existing value.
*/
char *
get_data_directory(const char *values[])
{
PGconn *pgconn;
PGresult *pgresult = NULL;
int rows;
/* Return existing value if any */
if (data_directory)
return data_directory;
/* No existing value, so query server */
rows = 0;
pgconn = connect_to_db(values);
if (pgconn != NULL)
{
pgresult = PQexec(pgconn, QUERY_DATA_DIRECTORY);
if (PQresultStatus(pgresult) == PGRES_TUPLES_OK)
rows = PQntuples(pgresult);
}
if (rows != 0)
{
char *dir;
dir = PQgetvalue(pgresult, 0, 0);
if (dir != NULL)
data_directory = strdup(dir);
}
/* Clean up */
if (pgresult != NULL)
PQclear(pgresult);
PQfinish(pgconn);
return data_directory;
}
void
update_state(int *pgstate, char *state)
{
if (strcmp(state, "idle") == 0)
*pgstate = STATE_IDLE;
else if (strcmp(state, "active") == 0)
*pgstate = STATE_RUNNING;
else if (strcmp(state, "idle in transaction") == 0)
*pgstate = STATE_IDLEINTRANSACTION;
else if (strcmp(state, "fastpath function call") == 0)
*pgstate = STATE_FASTPATH;
else if (strcmp(state, "idle in transaction (aborted)") == 0)
*pgstate = STATE_IDLEINTRANSACTION_ABORTED;
else if (strcmp(state, "disabled") == 0)
*pgstate = STATE_DISABLED;
else
*pgstate = STATE_UNDEFINED;
}
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