/*
 * derived from testlibpq3.c
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include "libpq-fe.h"


#define TABLESIZE 1000000		/* rows in table */
#define ITERS 10


static void
exit_nicely(PGconn *conn)
{
	PQfinish(conn);
	exit(1);
}

static char *
elapsed_time(struct timeval start_t, struct timeval elapse_t)
{
	static char buf[64];

	if (elapse_t.tv_usec < start_t.tv_usec)
	{
		elapse_t.tv_sec--;
		elapse_t.tv_usec += 1000000;
	}

	sprintf(buf, "%3ld.%06ld", (long) (elapse_t.tv_sec - start_t.tv_sec),
		   (long) (elapse_t.tv_usec - start_t.tv_usec));
	return buf;
}

static void
do_cmd(PGconn *conn, const char *cmd)
{
	PGresult   *res;
	struct timeval start_t;
	struct timeval elapse_t;

	gettimeofday(&start_t, NULL);
	res = PQexec(conn, cmd);
	gettimeofday(&elapse_t, NULL);
	if (PQresultStatus(res) != PGRES_COMMAND_OK)
	{
		fprintf(stderr, "%s\nCommand failed: %s", cmd, PQerrorMessage(conn));
		PQclear(res);
		exit_nicely(conn);
	}
	printf("executed %-.6s in %s sec\n", cmd,
		   elapsed_time(start_t, elapse_t));
	fflush(stdout);
	PQclear(res);
}

static void
do_select(PGconn *conn, const char *cmd)
{
	PGresult   *res;
	struct timeval start_t;
	struct timeval elapse_t;

	gettimeofday(&start_t, NULL);
	res = PQexec(conn, cmd);
	gettimeofday(&elapse_t, NULL);
	if (PQresultStatus(res) != PGRES_TUPLES_OK)
	{
		fprintf(stderr, "%s\nCommand failed: %s", cmd, PQerrorMessage(conn));
		PQclear(res);
		exit_nicely(conn);
	}
	printf("retrieved %4s tuples in %s sec\n", PQgetvalue(res, 0, 0),
		   elapsed_time(start_t, elapse_t));
	fflush(stdout);
	PQclear(res);
}

int
main(int argc, char **argv)
{
	const char *conninfo;
	PGconn	   *conn;
	PGresult   *res;
	char		cmd[1024];
	int			i;

	/*
	 * If the user supplies a parameter on the command line, use it as the
	 * conninfo string; otherwise default to setting dbname=postgres and using
	 * environment variables or defaults for all other connection parameters.
	 */
	if (argc > 1)
		conninfo = argv[1];
	else
		conninfo = "dbname = postgres";

	/* Make a connection to the database */
	conn = PQconnectdb(conninfo);

	/* Check to see that the backend connection was successfully made */
	if (PQstatus(conn) != CONNECTION_OK)
	{
		fprintf(stderr, "Connection to database failed: %s",
				PQerrorMessage(conn));
		exit_nicely(conn);
	}

	/* Ignore any error while dropping old table */
	res = PQexec(conn, "DROP TABLE testtab");
	PQclear(res);

	/* Set up test table */
	do_cmd(conn, "CREATE TABLE testtab(k int, d text)");
	sprintf(cmd, "INSERT INTO testtab "
			"SELECT x, repeat('x',350) FROM generate_series(1,%d) x",
			TABLESIZE);
	do_cmd(conn, cmd);
	do_cmd(conn, "CREATE INDEX testtabi ON testtab(k)");
	do_cmd(conn, "CLUSTER testtab USING testtabi");
	do_cmd(conn, "VACUUM ANALYZE testtab");

	for (i = 0; i < ITERS; i++)
	{
		int			st;

		sprintf(cmd, "DELETE FROM testtab WHERE random() < 1.0/50");
		do_cmd(conn, cmd);
		do_cmd(conn, "VACUUM testtab");
		sprintf(cmd, "INSERT INTO testtab "
				"SELECT (random() * %d)::int, repeat('x',350) "
				"FROM generate_series(1,%d)",
				TABLESIZE, TABLESIZE/50);
		do_cmd(conn, cmd);
		st = ((double) random() * (TABLESIZE - 1000)) / 0x7FFFFFFF;
		sprintf(cmd, "SELECT count(*) FROM testtab "
				"WHERE k BETWEEN %d AND %d",
				st, st + 1000);
		do_select(conn, cmd);
		do_select(conn, "SELECT count(*) FROM testtab");
	}

	/* close the connection to the database and cleanup */
	PQfinish(conn);

	return 0;
}