/* GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * 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 version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2011 Whamcloud, Inc.
 * Use is subject to license terms.
 *
 * Author: Niu Yawei <niu@whamcloud.com>
 */
/*
 * lustre/obdclass/lprocfs_jobstats.c
 */

#ifndef EXPORT_SYMTAB
# define EXPORT_SYMTAB
#endif
#define DEBUG_SUBSYSTEM S_CLASS

#ifndef __KERNEL__
# include <liblustre.h>
#endif

#include <obd_class.h>
#include <lprocfs_status.h>
#include <lustre/lustre_idl.h>

#if defined(LPROCFS)

/*
 * JobID formats & JobID environment variable names for supported
 * job schedulers:
 *
 * SLURM:
 *   JobID format:  32 bit integer.
 *   JobID env var: SLURM_JOB_ID.
 * SGE:
 *   JobID format:  Decimal integer range to 99999.
 *   JobID env var: JOB_ID.
 * LSF:
 *   JobID format:  6 digit integer by default (up to 999999), can be
 *		  increased to 10 digit (up to 2147483646).
 *   JobID env var: LSB_JOBID.
 * Loadleveler:
 *   JobID format:  String of machine_name.cluster_id.process_id, for
 *		  example: fr2n02.32.0
 *   JobID env var: LOADL_STEP_ID.
 * PBS:
 *   JobID format:  String of sequence_number[.server_name][@server].
 *   JobID env var: PBS_JOBID.
 * Maui/MOAB:
 *   JobID format:  Same as PBS.
 *   JobID env var: Same as PBS.
 */

struct job_stat {
	cfs_hlist_node_t      js_hash;
	cfs_list_t            js_list;
	cfs_atomic_t          js_refcount;
	char                  js_jobid[JOBSTATS_JOBID_SIZE];
	time_t                js_timestamp; /* seconds */
	struct lprocfs_stats *js_stats;
	struct obd_job_stats *js_jobstats;
};

static unsigned job_stat_hash(cfs_hash_t *hs, const void *key, unsigned mask)
{
	return cfs_hash_djb2_hash(key, strlen(key), mask);
}

static void *job_stat_key(cfs_hlist_node_t *hnode)
{
	struct job_stat *job;
	job = cfs_hlist_entry(hnode, struct job_stat, js_hash);
	return job->js_jobid;
}

static int job_stat_keycmp(const void *key, cfs_hlist_node_t *hnode)
{
	struct job_stat *job;
	job = cfs_hlist_entry(hnode, struct job_stat, js_hash);
	return (strlen(job->js_jobid) == strlen(key)) &&
	       !strncmp(job->js_jobid, key, strlen(key));
}

static void *job_stat_object(cfs_hlist_node_t *hnode)
{
	return cfs_hlist_entry(hnode, struct job_stat, js_hash);
}

static void job_stat_get(cfs_hash_t *hs, cfs_hlist_node_t *hnode)
{
	struct job_stat *job;
	job = cfs_hlist_entry(hnode, struct job_stat, js_hash);
	cfs_atomic_inc(&job->js_refcount);
}

static void job_free(struct job_stat *job)
{
	LASSERT(atomic_read(&job->js_refcount) == 0);
	LASSERT(job->js_jobstats);

	cfs_write_lock(&job->js_jobstats->ojs_lock);
	cfs_list_del_init(&job->js_list);
	cfs_write_unlock(&job->js_jobstats->ojs_lock);

	lprocfs_free_stats(&job->js_stats);
	OBD_FREE_PTR(job);
}

static void job_putref(struct job_stat *job)
{
	LASSERT(atomic_read(&job->js_refcount) > 0);
	if (atomic_dec_and_test(&job->js_refcount))
		job_free(job);
}

static void job_stat_put_locked(cfs_hash_t *hs, cfs_hlist_node_t *hnode)
{
	struct job_stat *job;
	job = cfs_hlist_entry(hnode, struct job_stat, js_hash);
	job_putref(job);
}

static void job_stat_exit(cfs_hash_t *hs, cfs_hlist_node_t *hnode)
{
	CERROR("Should not have any items!");
}

static cfs_hash_ops_t job_stats_hash_ops = {
	.hs_hash       = job_stat_hash,
	.hs_key        = job_stat_key,
	.hs_keycmp     = job_stat_keycmp,
	.hs_object     = job_stat_object,
	.hs_get        = job_stat_get,
	.hs_put_locked = job_stat_put_locked,
	.hs_exit       = job_stat_exit,
};

static struct job_stat *job_alloc(char *jobid, struct obd_job_stats *jobs)
{
	struct job_stat *job;

	LASSERT(jobs->ojs_cntr_num && jobs->ojs_cntr_init_fn);

	OBD_ALLOC_PTR(job);
	if (job == NULL)
		return NULL;

	job->js_stats = lprocfs_alloc_stats(jobs->ojs_cntr_num, 0);
	if (job->js_stats == NULL) {
		OBD_FREE_PTR(job);
		return NULL;
	}

	jobs->ojs_cntr_init_fn(job->js_stats);

	memcpy(job->js_jobid, jobid, JOBSTATS_JOBID_SIZE);
	job->js_timestamp = cfs_time_current_sec();
	job->js_jobstats = jobs;
	CFS_INIT_HLIST_NODE(&job->js_hash);
	CFS_INIT_LIST_HEAD(&job->js_list);
	cfs_atomic_set(&job->js_refcount, 1);

	return job;
}

int lprocfs_job_stats_log(struct obd_device *obd, char *jobid,
			  int event, long amount)
{
	struct obd_job_stats *stats = &obd->u.obt.obt_jobstats;
	struct job_stat *job, *job2;
	ENTRY;

	LASSERT(stats && stats->ojs_hash);

	if (!jobid || !strlen(jobid))
		RETURN(-EINVAL);

	if (strlen(jobid) >= JOBSTATS_JOBID_SIZE) {
		CERROR("Invalid jobid size (%lu), expect(%d)\n",
		       (unsigned long)strlen(jobid) + 1, JOBSTATS_JOBID_SIZE);
		RETURN(-EINVAL);
	}

	job = cfs_hash_lookup(stats->ojs_hash, jobid);
	if (job)
		goto found;

	job = job_alloc(jobid, stats);
	if (job == NULL)
		RETURN(-ENOMEM);

	job2 = cfs_hash_findadd_unique(stats->ojs_hash, job->js_jobid,
				       &job->js_hash);
	if (job2 != job) {
		job_putref(job);
		job = job2;
		LASSERT(!cfs_list_empty(&job->js_list));
	} else {
		LASSERT(cfs_list_empty(&job->js_list));
		cfs_write_lock(&stats->ojs_lock);
		cfs_list_add_tail(&job->js_list, &stats->ojs_list);
		cfs_write_unlock(&stats->ojs_lock);
	}

found:
	LASSERT(stats == job->js_jobstats);
	LASSERT(stats->ojs_cntr_num > event);
	job->js_timestamp = cfs_time_current_sec();
	lprocfs_counter_add(job->js_stats, event, amount);

	job_putref(job);
	RETURN(0);
}
EXPORT_SYMBOL(lprocfs_job_stats_log);

static int job_iter_callback(cfs_hash_t *hs, cfs_hash_bd_t *bd,
			     cfs_hlist_node_t *hnode, void *data)
{
	time_t oldest = *((time_t *)data);
	struct job_stat *job;

	job = cfs_hlist_entry(hnode, struct job_stat, js_hash);
	if (!oldest || job->js_timestamp < oldest)
		cfs_hash_bd_del_locked(hs, bd, hnode);

	return 0;
}

void lprocfs_job_stats_fini(struct obd_device *obd)
{
	struct obd_job_stats *stats = &obd->u.obt.obt_jobstats;
	time_t oldest = 0;

	if (stats->ojs_hash == NULL)
		return;
	cfs_timer_disarm(&stats->ojs_cleanup_timer);
	cfs_hash_for_each_safe(stats->ojs_hash, job_iter_callback, &oldest);
	cfs_hash_putref(stats->ojs_hash);
	stats->ojs_hash = NULL;
	LASSERT(cfs_list_empty(&stats->ojs_list));
}
EXPORT_SYMBOL(lprocfs_job_stats_fini);

static void *lprocfs_jobstats_seq_start(struct seq_file *p, loff_t *pos)
{
	struct obd_job_stats *stats = p->private;
	loff_t off = *pos;
	struct job_stat *job;

	cfs_read_lock(&stats->ojs_lock);
	if (off == 0)
		return SEQ_START_TOKEN;
	off--;
	cfs_list_for_each_entry(job, &stats->ojs_list, js_list) {
		if (!off--)
			return job;
	}
	return NULL;
}

static void lprocfs_jobstats_seq_stop(struct seq_file *p, void *v)
{
	struct obd_job_stats *stats = p->private;

	cfs_read_unlock(&stats->ojs_lock);
}

static void *lprocfs_jobstats_seq_next(struct seq_file *p, void *v, loff_t *pos)
{
	struct obd_job_stats *stats = p->private;
	struct job_stat *job;
	cfs_list_t *next;

	++*pos;
	if (v == SEQ_START_TOKEN) {
		next = stats->ojs_list.next;
	} else {
		job = (struct job_stat *)v;
		next = job->js_list.next;
	}

	return next == &stats->ojs_list ? NULL :
		cfs_list_entry(next, struct job_stat, js_list);
}

/*
 * Example of output on MDT:
 *
 * job_stats:
 * - job_id:        test_id.222.25844
 *   snapshot_time: 1322494486
 *   open:          { samples:	       3, unit: reqs }
 *   close:         { samples:	       3, unit: reqs }
 *   mknod:         { samples:	       0, unit: reqs }
 *   link:          { samples:	       0, unit: reqs }
 *   unlink:        { samples:	       0, unit: reqs }
 *   mkdir:         { samples:	       0, unit: reqs }
 *   rmdir:         { samples:	       0, unit: reqs }
 *   rename:        { samples:	       1, unit: reqs }
 *   getattr:       { samples:	       7, unit: reqs }
 *   setattr:       { samples:	       0, unit: reqs }
 *   getxattr:      { samples:	       0, unit: reqs }
 *   setxattr:      { samples:	       0, unit: reqs }
 *   statfs:        { samples:	       0, unit: reqs }
 *   sync:          { samples:	       0, unit: reqs }
 *
 * Example of output on OST:
 *
 * job_stats:
 * - job_id         4854
 *   snapshot_time: 1322494602
 *   read:          { samples:  0, unit: bytes, min:  0, max:  0, sum:  0 }
 *   write:         { samples:  1, unit: bytes, min: 10, max: 10, sum: 10 }
 *   setattr:       { samples:  0, unit: reqs }
 *   punch:         { samples:  0, unit: reqs }
 *   sync:          { samples:  0, unit: reqs }
 */

static const char spaces[] = "                    ";

static int inline width(const char *str, int len)
{
	return len - min((int)strlen(str), 15);
}

static int lprocfs_jobstats_seq_show(struct seq_file *p, void *v)
{
	struct job_stat *job = v;
	struct lprocfs_stats *s;
	struct lprocfs_counter ret, *cntr;
	int i;

	if (v == SEQ_START_TOKEN) {
		seq_printf(p, "job_stats:\n");
		return 0;
	}

	seq_printf(p, "- %-16s %s\n", "job_id:", job->js_jobid);
	seq_printf(p, "  %-16s %ld\n", "snapshot_time:", job->js_timestamp);

	s = job->js_stats;
	for (i = 0; i < s->ls_num; i++) {
		cntr = &(s->ls_percpu[0]->lp_cntr[i]);
		lprocfs_stats_collect(s, i, &ret);

		seq_printf(p, "  %s:%.*s { samples: %11"LPF64"u",
			   cntr->lc_name, width(cntr->lc_name, 15), spaces,
			   ret.lc_count);
		if (cntr->lc_units[0] != '\0')
			seq_printf(p, ", unit: %5s", cntr->lc_units);

		if (cntr->lc_config & LPROCFS_CNTR_AVGMINMAX) {
			seq_printf(p, ", min:%8"LPF64"u, max:%8"LPF64"u,"
				   " sum:%16"LPF64"u",
				   ret.lc_count ? ret.lc_min : 0,
				   ret.lc_count ? ret.lc_max : 0,
				   ret.lc_count ? ret.lc_sum : 0);
		}
		if (cntr->lc_config & LPROCFS_CNTR_STDDEV) {
			seq_printf(p, ", sumsq: %18"LPF64"u",
				   ret.lc_count ? ret.lc_sumsquare : 0);
		}

		seq_printf(p, " }\n");

	}
	return 0;
}

struct seq_operations lprocfs_jobstats_seq_sops = {
	start: lprocfs_jobstats_seq_start,
	stop:  lprocfs_jobstats_seq_stop,
	next:  lprocfs_jobstats_seq_next,
	show:  lprocfs_jobstats_seq_show,
};

static int lprocfs_jobstats_seq_open(struct inode *inode, struct file *file)
{
	struct proc_dir_entry *dp = PDE(inode);
	struct seq_file *seq;
	int rc;

	if (LPROCFS_ENTRY_AND_CHECK(dp))
		return -ENOENT;

	rc = seq_open(file, &lprocfs_jobstats_seq_sops);
	if (rc) {
		LPROCFS_EXIT();
		return rc;
	}
	seq = file->private_data;
	seq->private = dp->data;
	return 0;
}

static ssize_t lprocfs_jobstats_seq_write(struct file *file, const char *buf,
					  size_t len, loff_t *off)
{
	struct seq_file *seq = file->private_data;
	struct obd_job_stats *stats = seq->private;
	char jobid[JOBSTATS_JOBID_SIZE];
	int all = 0;
	struct job_stat *job;

	if (!memcmp(buf, "clear", strlen("clear"))) {
		all = 1;
	} else if (len < JOBSTATS_JOBID_SIZE) {
		memset(jobid, 0, JOBSTATS_JOBID_SIZE);
		/* Trim '\n' if any */
		if (buf[len - 1] == '\n')
			memcpy(jobid, buf, len - 1);
		else
			memcpy(jobid, buf, len);
	} else {
		return -EINVAL;
	}

	LASSERT(stats->ojs_hash);
	if (all) {
		time_t oldest = 0;
		cfs_hash_for_each_safe(stats->ojs_hash, job_iter_callback,
				       &oldest);
		return len;
	}

	if (!strlen(jobid))
		return -EINVAL;

	job = cfs_hash_lookup(stats->ojs_hash, jobid);
	if (!job)
		return -EINVAL;

	cfs_hash_del_key(stats->ojs_hash, jobid);

	job_putref(job);
	return len;
}

struct file_operations lprocfs_jobstats_seq_fops = {
	.owner   = THIS_MODULE,
	.open    = lprocfs_jobstats_seq_open,
	.read    = seq_read,
	.write   = lprocfs_jobstats_seq_write,
	.llseek  = seq_lseek,
	.release = lprocfs_seq_release,
};

static void job_cleanup_callback(unsigned long data)
{
	struct obd_job_stats *stats = (struct obd_job_stats *)data;
	time_t oldest;

	if (stats->ojs_cleanup_interval) {
		oldest = cfs_time_current_sec() - stats->ojs_cleanup_interval;
		cfs_hash_for_each_safe(stats->ojs_hash, job_iter_callback,
				       &oldest);
		cfs_timer_arm(&stats->ojs_cleanup_timer,
			      cfs_time_shift(stats->ojs_cleanup_interval));
	}
}

int lprocfs_job_stats_init(struct obd_device *obd, int cntr_num,
			   cntr_init_callback init_fn)
{
	struct proc_dir_entry *entry;
	struct obd_job_stats *stats;
	ENTRY;

	LASSERT(obd->obd_proc_entry != NULL);
	LASSERT(obd->obd_type->typ_name);

	if (strcmp(obd->obd_type->typ_name, LUSTRE_MDT_NAME) &&
	    strcmp(obd->obd_type->typ_name, LUSTRE_OST_NAME)) {
		CERROR("Invalid obd device type.\n");
		RETURN(-EINVAL);
	}
	stats = &obd->u.obt.obt_jobstats;

	LASSERT(stats->ojs_hash == NULL);
	stats->ojs_hash = cfs_hash_create("JOB_STATS",
					  HASH_JOB_STATS_CUR_BITS,
					  HASH_JOB_STATS_MAX_BITS,
					  HASH_JOB_STATS_BKT_BITS, 0,
					  CFS_HASH_MIN_THETA,
					  CFS_HASH_MAX_THETA,
					  &job_stats_hash_ops,
					  CFS_HASH_DEFAULT);
	if (stats->ojs_hash == NULL)
		RETURN(-ENOMEM);

	CFS_INIT_LIST_HEAD(&stats->ojs_list);
	cfs_rwlock_init(&stats->ojs_lock);
	stats->ojs_cntr_num = cntr_num;
	stats->ojs_cntr_init_fn = init_fn;
	cfs_timer_init(&stats->ojs_cleanup_timer, job_cleanup_callback, stats);
	stats->ojs_cleanup_interval = 600; /* 10 mins by default */
	cfs_timer_arm(&stats->ojs_cleanup_timer,
		      cfs_time_shift(stats->ojs_cleanup_interval));

	LPROCFS_WRITE_ENTRY();
	entry = create_proc_entry("job_stats", 0644, obd->obd_proc_entry);
	LPROCFS_WRITE_EXIT();
	if (entry) {
		entry->proc_fops = &lprocfs_jobstats_seq_fops;
		entry->data = stats;
		RETURN(0);
	} else {
		lprocfs_job_stats_fini(obd);
		RETURN(-ENOMEM);
	}
}
EXPORT_SYMBOL(lprocfs_job_stats_init);

int lprocfs_rd_job_interval(char *page, char **start, off_t off,
			    int count, int *eof, void *data)
{
	struct obd_device *obd = (struct obd_device *)data;
	struct obd_job_stats *stats;

	LASSERT(obd != NULL);
	stats = &obd->u.obt.obt_jobstats;
	*eof = 1;
	return snprintf(page, count, "%d\n", stats->ojs_cleanup_interval);
}
EXPORT_SYMBOL(lprocfs_rd_job_interval);

int lprocfs_wr_job_interval(struct file *file, const char *buffer,
			    unsigned long count, void *data)
{
	struct obd_device *obd = (struct obd_device *)data;
	struct obd_job_stats *stats;
	int val, rc;

	LASSERT(obd != NULL);
	stats = &obd->u.obt.obt_jobstats;

	rc = lprocfs_write_helper(buffer, count, &val);
	if (rc)
		return rc;

	stats->ojs_cleanup_interval = val;
	if (!stats->ojs_cleanup_interval)
		cfs_timer_disarm(&stats->ojs_cleanup_timer);
	else
		cfs_timer_arm(&stats->ojs_cleanup_timer,
			      cfs_time_shift(stats->ojs_cleanup_interval));

	return count;

}
EXPORT_SYMBOL(lprocfs_wr_job_interval);

#endif /* LPROCFS*/