/*
 * Authors: Petr Spacek <pspacek@redhat.com>
 *
 * Copyright (C) 2012  Red Hat
 * see file 'COPYING' for use and warranty information
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; version 2 or later
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <isc/mem.h>
#include <isc/result.h>
#include <isc/util.h>

#include <dns/result.h>

#include <string.h>
#include <unistd.h>

void
logger(const char *format, ...)
{
	va_list args;

	va_start(args, format);
	vfprintf(stderr, format, args);
	va_end(args);
}

#define CHECK(op)						\
	do {							\
		logger("%4u: %s = ", __LINE__, #op);		\
		result = (op);					\
		logger("%s\n", dns_result_totext(result));	\
		if (result != ISC_R_SUCCESS)			\
			goto cleanup;				\
	} while (0)

#define PRINT(op)						\
	do {							\
		logger("%4u: %s\n", __LINE__, #op);		\
		(op);						\
	} while (0)

void wait() {
	fprintf(stderr, "\nPress ENTER to continue ...\n");
	getchar();
}

#define BLOCK_SIZE  1024
#define BLOCK_COUNT 1024*1024

void *blocks[BLOCK_COUNT] = {};

int
main (int argc, char ** argv) {
	isc_result_t result = ISC_R_SUCCESS;
	isc_mem_t *mctx = NULL;
	size_t inuse;

	CHECK(isc_mem_create2(0, 0, &mctx, ISC_MEMFLAG_DEFAULT));

	inuse = isc_mem_inuse(mctx);
	printf("inuse = %lu\n", inuse);
	isc_mem_stats(mctx, stderr);
	logger("Real memory consumption at this point is near to 0.\n");
	wait();

	logger("getting blocks");
	for (int i = 1; i <= BLOCK_COUNT; i++) {
		if (i % 1024 == 0)
			logger("\rgetting block %d/%d", i, BLOCK_COUNT);
		blocks[i-1] = isc_mem_get(mctx, BLOCK_SIZE);
	}
	logger(": done => got %lu bytes\n", BLOCK_COUNT*BLOCK_SIZE);
	printf("block[BLOCK_COUNT-1] = %p\n", blocks[BLOCK_COUNT-1]);
	inuse = isc_mem_inuse(mctx);
	printf("inuse = %lu\n", inuse);
	isc_mem_stats(mctx, stderr);
	logger("Real memory consumption at this point is ~ 1 GB.\n");
	wait();

	logger("putting blocks");
	for (int i = 1; i <= BLOCK_COUNT; i++) {
		if (i % 1024 == 0)
			logger("\rputting block %d/%d", i, BLOCK_COUNT);
		isc_mem_put(mctx, blocks[i-1], BLOCK_SIZE);
	}
	logger(": done => put %lu bytes\n", BLOCK_COUNT*BLOCK_SIZE);
	inuse = isc_mem_inuse(mctx);
	printf("inuse = %lu\n", inuse);
	isc_mem_stats(mctx, stderr);
	logger("Real memory consumption at this point is still ~ 1 GB !\n");
	wait();

	logger("destroying memory context\n");
	isc_mem_destroy(&mctx);
	logger("Real memory consumption at this point is finally near 0.\n");
	wait();

cleanup:
	(void) argc;
	(void) argv;

	return 0;
}