/*

 * blktrace output analysis: generate a timeline & gather statistics

 *

 * Copyright (C) 2006 Alan D. Brunelle <Alan.Brunelle@hp.com>

 *

 *  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; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  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 <stdio.h>

#include <unistd.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <sys/mman.h>

#include <string.h>

#include "blktrace.h"

#include "globals.h"

#define DEF_LEN	(16 * 1024 * 1024)

static int fd;

static void *cur_map = MAP_FAILED;

static off_t cur_min, cur, cur_max, total_size;

static size_t len;

static struct blk_io_trace *next_t;

static long pgsz;

int data_is_native = -1;

static inline size_t min_len(size_t a, size_t b)

{

	return a < b ? a : b;

}

static inline size_t convert_to_cpu(struct blk_io_trace *t,

                                    struct blk_io_trace *tp,

				    void **pdu)

{

	if (data_is_native == -1)

		check_data_endianness(t->magic);

	if (data_is_native)

		memcpy(tp, t, sizeof(*tp));

	else {

		tp->magic	= be32_to_cpu(t->magic);

		tp->sequence	= be32_to_cpu(t->sequence);

		tp->time	= be64_to_cpu(t->time);

		tp->sector	= be64_to_cpu(t->sector);

		tp->bytes	= be32_to_cpu(t->bytes);

		tp->action	= be32_to_cpu(t->action);

		tp->pid		= be32_to_cpu(t->pid);

		tp->device	= be32_to_cpu(t->device);

		tp->cpu		= be16_to_cpu(t->cpu);

		tp->error	= be16_to_cpu(t->error);

		tp->pdu_len	= be16_to_cpu(t->pdu_len);

	}

	if (tp->pdu_len) {

		*pdu = malloc(tp->pdu_len);

		memcpy(*pdu, t+1, tp->pdu_len);

	} else

		*pdu = NULL;

	return sizeof(*tp) + tp->pdu_len;

}

static int move_map(void)

{

	if (cur_map != MAP_FAILED)

		munmap(cur_map, len);

	cur_min = (cur & ~(pgsz-1));

	len = min_len(DEF_LEN, total_size - cur_min);

	if (len < sizeof(*next_t))

		return 0;

	cur_map = mmap(NULL, len, PROT_READ, MAP_SHARED, fd,

		       cur_min);

	if (cur_map == MAP_FAILED) {

		perror("mmap");

		exit(1);

	}

	cur_max = cur_min + len;

	return (cur < cur_max);

}

void setup_ifile(char *fname)

{

	struct stat buf;

	pgsz = sysconf(_SC_PAGESIZE);

	fd = my_open(fname, O_RDONLY);

	if (fd < 0) {

		perror(fname);

		exit(1);

	}

	if (fstat(fd, &buf) < 0) {

		perror(fname);

		exit(1);

	}

	total_size = buf.st_size;

	if (!move_map())

		exit(0);

}

void cleanup_ifile(void)

{

	if (cur_map != MAP_FAILED)

		munmap(cur_map, len);

	close(fd);

}

int next_trace(struct blk_io_trace *t, void **pdu)

{

	size_t this_len;

	if ((cur + 512) > cur_max)

		if (!move_map()) {

			cleanup_ifile();

			return 0;

		}

	next_t = cur_map + (cur - cur_min);

	this_len = convert_to_cpu(next_t, t, pdu);

	cur += this_len;

	return 1;

}

double pct_done(void)

{

	return 100.0 * ((double)cur / (double)total_size);

}