/*****************************************************************************\
 *  burst_buffer_generic.c - Generic library for managing a burst_buffer
 *****************************************************************************
 *  Copyright (C) 2014-2015 SchedMD LLC.
 *  Written by Morris Jette <jette@schedmd.com>
 *
 *  This file is part of Slurm, a resource management program.
 *  For details, see <https://slurm.schedmd.com/>.
 *  Please also read the included file: DISCLAIMER.
 *
 *  Slurm 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.
 *
 *  In addition, as a special exception, the copyright holders give permission
 *  to link the code of portions of this program with the OpenSSL library under
 *  certain conditions as described in each individual source file, and
 *  distribute linked combinations including the two. You must obey the GNU
 *  General Public License in all respects for all of the code used other than
 *  OpenSSL. If you modify file(s) with this exception, you may extend this
 *  exception to your version of the file(s), but you are not obligated to do
 *  so. If you do not wish to do so, delete this exception statement from your
 *  version.  If you delete this exception statement from all source files in
 *  the program, then also delete it here.
 *
 *  Slurm 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 Slurm; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA.
\*****************************************************************************/

#include <poll.h>
#include <stdlib.h>
#include <unistd.h>

#include "slurm/slurm.h"

#include "src/common/list.h"
#include "src/common/pack.h"
#include "src/common/parse_config.h"
#include "src/common/slurm_protocol_api.h"
#include "src/common/timers.h"
#include "src/common/uid.h"
#include "src/common/xmalloc.h"
#include "src/common/xstring.h"
#include "src/slurmctld/locks.h"
#include "src/slurmctld/reservation.h"
#include "src/slurmctld/slurmctld.h"
#include "src/plugins/burst_buffer/common/burst_buffer_common.h"

/*
 * These variables are required by the generic plugin interface.  If they
 * are not found in the plugin, the plugin loader will ignore it.
 *
 * plugin_name - a string giving a human-readable description of the
 * plugin.  There is no maximum length, but the symbol must refer to
 * a valid string.
 *
 * plugin_type - a string suggesting the type of the plugin or its
 * applicability to a particular form of data or method of data handling.
 * If the low-level plugin API is used, the contents of this string are
 * unimportant and may be anything.  Slurm uses the higher-level plugin
 * interface which requires this string to be of the form
 *
 *      <application>/<method>
 *
 * where <application> is a description of the intended application of
 * the plugin (e.g., "burst_buffer" for Slurm burst_buffer) and <method> is a
 * description of how this plugin satisfies that application.  Slurm will only
 * load a burst_buffer plugin if the plugin_type string has a prefix of
 * "burst_buffer/".
 *
 * plugin_version - an unsigned 32-bit integer containing the Slurm version
 * (major.minor.micro combined into a single number).
 */
const char plugin_name[]        = "burst_buffer generic plugin";
const char plugin_type[]        = "burst_buffer/generic";
const uint32_t plugin_version   = SLURM_VERSION_NUMBER;

/*
 * init() is called when the plugin is loaded, before any other functions
 * are called.  Put global initialization here.
 */
extern int init(void)
{
	return SLURM_SUCCESS;
}

/*
 * fini() is called when the plugin is unloaded. Free all memory.
 */
extern int fini(void)
{
	return SLURM_SUCCESS;
}

/*
 * Return the total burst buffer size in MB
 */
extern uint64_t bb_p_get_system_size(void)
{
	uint64_t size = 0;
	return size;
}

/*
 * Load the current burst buffer state (e.g. how much space is available now).
 * Run at the beginning of each scheduling cycle in order to recognize external
 * changes to the burst buffer state (e.g. capacity is added, removed, fails,
 * etc.)
 *
 * init_config IN - true if called as part of slurmctld initialization
 * Returns a Slurm errno.
 */
extern int bb_p_load_state(bool init_config)
{
	return SLURM_SUCCESS;
}

/*
 * Return string containing current burst buffer status
 * argc IN - count of status command arguments
 * argv IN - status command arguments
 * RET status string, release memory using xfree()
 */
extern char *bb_p_get_status(uint32_t argc, char **argv)
{
	return NULL;
}

/*
 * Note configuration may have changed. Handle changes in BurstBufferParameters.
 *
 * Returns a Slurm errno.
 */
extern int bb_p_reconfig(void)
{
	return SLURM_SUCCESS;
}

/*
 * Pack current burst buffer state information for network transmission to
 * user (e.g. "scontrol show burst")
 *
 * Returns a Slurm errno.
 */
extern int bb_p_state_pack(uid_t uid, Buf buffer, uint16_t protocol_version)
{
	return SLURM_SUCCESS;
}

/*
 * Preliminary validation of a job submit request with respect to burst buffer
 * options. Performed after setting default account + qos, but prior to
 * establishing job ID or creating script file.
 *
 * Returns a Slurm errno.
 */
extern int bb_p_job_validate(job_desc_msg_t *job_desc, uid_t submit_uid)
{
	return SLURM_SUCCESS;
}

/*
 * Secondary validation of a job submit request with respect to burst buffer
 * options. Performed after establishing job ID and creating script file.
 *
 * Returns a Slurm errno.
 */
extern int bb_p_job_validate2(job_record_t *job_ptr, char **err_msg)
{
	return SLURM_SUCCESS;
}

/*
 * Fill in the tres_cnt (in MB) based off the job record
 * NOTE: Based upon job-specific burst buffers, excludes persistent buffers
 * IN job_ptr - job record
 * IN/OUT tres_cnt - fill in this already allocated array with tres_cnts
 * IN locked - if the assoc_mgr tres read locked is locked or not
 */
extern void bb_p_job_set_tres_cnt(job_record_t *job_ptr, uint64_t *tres_cnt,
				  bool locked)
{
}

/*
 * For a given job, return our best guess if when it might be able to start
 */
extern time_t bb_p_job_get_est_start(job_record_t *job_ptr)
{
	time_t est_start = time(NULL);
	return est_start;
}

/*
 * Attempt to allocate resources and begin file staging for pending jobs.
 */
extern int bb_p_job_try_stage_in(List job_queue)
{
	return SLURM_SUCCESS;
}

/*
 * Determine if a job's burst buffer stage-in is complete
 * job_ptr IN - Job to test
 * test_only IN - If false, then attempt to allocate burst buffer if possible
 *
 * RET: 0 - stage-in is underway
 *      1 - stage-in complete
 *     -1 - stage-in not started or burst buffer in some unexpected state
 */
extern int bb_p_job_test_stage_in(job_record_t *job_ptr, bool test_only)
{
	return 1;
}

/* Attempt to claim burst buffer resources.
 * At this time, bb_g_job_test_stage_in() should have been run successfully AND
 * the compute nodes selected for the job.
 *
 * Returns a Slurm errno.
 */
extern int bb_p_job_begin(job_record_t *job_ptr)
{
	return SLURM_SUCCESS;
}

/* Revoke allocation, but do not release resources.
 * Executed after bb_p_job_begin() if there was an allocation failure.
 * Does not release previously allocated resources.
 *
 * Returns a Slurm errno.
 */
extern int bb_p_job_revoke_alloc(job_record_t *job_ptr)
{
	return SLURM_SUCCESS;
}

/*
 * Trigger a job's burst buffer stage-out to begin
 *
 * Returns a Slurm errno.
 */
extern int bb_p_job_start_stage_out(job_record_t *job_ptr)
{
	return SLURM_SUCCESS;
}

/*
 * Determine if a job's burst buffer post_run operation is complete
 *
 * RET: 0 - post_run is underway
 *      1 - post_run complete
 *     -1 - fatal error
 */
extern int bb_p_job_test_post_run(job_record_t *job_ptr)
{
	return 1;
}

/*
 * Determine if a job's burst buffer stage-out is complete
 *
 * RET: 0 - stage-out is underway
 *      1 - stage-out complete
 *     -1 - fatal error
 */
extern int bb_p_job_test_stage_out(job_record_t *job_ptr)
{
	return 1;
}

/*
 * Terminate any file staging and completely release burst buffer resources
 *
 * Returns a Slurm errno.
 */
extern int bb_p_job_cancel(job_record_t *job_ptr)
{
	return SLURM_SUCCESS;
}

/*
 * Translate a burst buffer string to it's equivalent TRES string
 * Caller must xfree the return value
 */
extern char *bb_p_xlate_bb_2_tres_str(char *burst_buffer)
{
	return NULL;
}