/*****************************************************************************\
 *  file_bcast.c - File transfer agent (handles message traffic)
 *****************************************************************************
 *  Copyright (C) 2015 SchedMD LLC.
 *  Copyright (C) 2008-2009 Lawrence Livermore National Security.
 *  Copyright (C) 2006-2007 The Regents of the University of California.
 *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
 *  Written by Morris Jette <jette1@llnl.gov>
 *  CODE-OCEC-09-009. All rights reserved.
 *
 *  This file is part of SLURM, a resource management program.
 *  For details, see <http://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.
\*****************************************************************************/

#if HAVE_CONFIG_H
#  include "config.h"
#endif

#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#if HAVE_LIBZ
#  include <zlib.h>
#  if defined(__CYGWIN__)
#    include <fcntl.h>
#    include <io.h>
#    define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
#  else
#    define SET_BINARY_MODE(file)
#  endif
#  define CHUNK (256 * 1024)
   z_stream strm;
#endif

#include "slurm/slurm_errno.h"
#include "src/common/file_bcast.h"
#include "src/common/forward.h"
#include "src/common/hostlist.h"
#include "src/common/log.h"
#include "src/common/macros.h"
#include "src/common/read_config.h"
#include "src/common/slurm_protocol_api.h"
#include "src/common/slurm_protocol_defs.h"
#include "src/common/slurm_protocol_interface.h"
#include "src/common/slurm_time.h"
#include "src/common/timers.h"
#include "src/common/uid.h"
#include "src/common/xmalloc.h"
#include "src/common/xstring.h"

#define MAX_RETRIES     10
#define MAX_THREADS      8	/* These can be huge messages, so
				 * only run MAX_THREADS at one time */
typedef struct thd {
	pthread_t thread;	/* thread ID */
	slurm_msg_t msg;	/* message to send */
	int rc;			/* highest return codes from RPC */
	char *nodelist;
} thd_t;

static int fd;				/* source file descriptor */
static struct stat f_stat;		/* source file stats */
job_sbcast_cred_msg_t *sbcast_cred;	/* job alloc info and sbcast cred */

static int   _bcast_file(struct bcast_parameters *params);
static int   _file_bcast(struct bcast_parameters *params,
			 file_bcast_msg_t *bcast_msg,
			 job_sbcast_cred_msg_t *sbcast_cred);
static int   _file_state(struct bcast_parameters *params);
static ssize_t _get_block(struct bcast_parameters *params,
			  char *buffer, size_t buf_size);
static int  _get_job_info(struct bcast_parameters *params);


static int _file_state(struct bcast_parameters *params)
{
	/* validate the source file */
	if ((fd = open(params->src_fname, O_RDONLY)) < 0) {
		error("Can't open `%s`: %s", params->src_fname,
			strerror(errno));
		return SLURM_ERROR;
	}
	if (fstat(fd, &f_stat)) {
		error("Can't stat `%s`: %s", params->src_fname,
			strerror(errno));
		return SLURM_ERROR;
	}
	verbose("modes    = %o", (unsigned int) f_stat.st_mode);
	verbose("uid      = %d", (int) f_stat.st_uid);
	verbose("gid      = %d", (int) f_stat.st_gid);
	verbose("atime    = %s", slurm_ctime2(&f_stat.st_atime));
	verbose("mtime    = %s", slurm_ctime2(&f_stat.st_mtime));
	verbose("ctime    = %s", slurm_ctime2(&f_stat.st_ctime));
	verbose("size     = %ld", (long) f_stat.st_size);

	return SLURM_SUCCESS;
}

/* get details about this slurm job: jobid and allocated node */
static int _get_job_info(struct bcast_parameters *params)
{
	int rc;

	xassert(params->job_id != NO_VAL);

	rc = slurm_sbcast_lookup(params->job_id, params->step_id, &sbcast_cred);
	if (rc != SLURM_SUCCESS) {
		if (params->step_id == NO_VAL) {
			error("Slurm job ID %u lookup error: %s",
			      params->job_id,
			      slurm_strerror(slurm_get_errno()));
		} else {
			error("Slurm step ID %u.%u lookup error: %s",
			      params->job_id, params->step_id,
			      slurm_strerror(slurm_get_errno()));
		}
		return rc;
	}
	if (params->step_id == NO_VAL)
		verbose("jobid      = %u", params->job_id);
	else
		verbose("stepid     = %u.%u", params->job_id, params->step_id);
	verbose("node_cnt   = %u", sbcast_cred->node_cnt);
	verbose("node_list  = %s", sbcast_cred->node_list);
	/* also see sbcast_cred->node_addr (array) */

	if (params->verbose)
		print_sbcast_cred(sbcast_cred->sbcast_cred);

	/* do not bother to release the return message,
	 * we need to preserve and use most of the information later */

	return rc;
}

/* Issue the RPC to transfer the file's data */
static int _file_bcast(struct bcast_parameters *params,
		       file_bcast_msg_t *bcast_msg,
		       job_sbcast_cred_msg_t *sbcast_cred)
{
	List ret_list = NULL;
	ListIterator itr;
	ret_data_info_t *ret_data_info = NULL;
	int rc = 0, msg_rc;
	slurm_msg_t msg;

	slurm_msg_t_init(&msg);
	msg.data = bcast_msg;
	msg.msg_type = REQUEST_FILE_BCAST;

	ret_list = slurm_send_recv_msgs(
		sbcast_cred->node_list, &msg, params->timeout, true);
	if (ret_list == NULL) {
		error("slurm_send_recv_msgs: %m");
		exit(1);
	}

	itr = list_iterator_create(ret_list);
	while ((ret_data_info = list_next(itr))) {
		msg_rc = slurm_get_return_code(ret_data_info->type,
					       ret_data_info->data);
		if (msg_rc == SLURM_SUCCESS)
			continue;

		error("REQUEST_FILE_BCAST(%s): %s",
		      ret_data_info->node_name,
		      slurm_strerror(msg_rc));
		rc = MAX(rc, msg_rc);
	}
	list_iterator_destroy(itr);
	FREE_NULL_LIST(ret_list);

	return rc;
}

/* load a buffer with data from the file to broadcast,
 * return number of bytes read, zero on end of file */
static ssize_t _get_block(struct bcast_parameters *params,
			  char *buffer, size_t buf_size)
{
	static int fd = 0;
	ssize_t buf_used = 0, rc;

	if (!fd) {
		fd = open(params->src_fname, O_RDONLY);
		if (!fd) {
			error("Can't open `%s`: %s",
			      params->src_fname, strerror(errno));
			return SLURM_ERROR;
		}
	}

	while (buf_size) {
		rc = read(fd, buffer, buf_size);
		if (rc == -1) {
			if ((errno == EINTR) || (errno == EAGAIN))
				continue;
			error("Can't read `%s`: %s",
			      params->src_fname, strerror(errno));
			return SLURM_ERROR;
		} else if (rc == 0) {
			debug("end of file reached");
			break;
		}

		buffer   += rc;
		buf_size -= rc;
		buf_used += rc;
	}
	return buf_used;
}

static int32_t _compress_data(struct bcast_parameters *params, char **buffer,
			      int32_t block_len)
{
#if HAVE_LIBZ
	int buf_in_offset = 0;
	int buf_out_offset = 0, buf_out_size = 0;
	int flush = Z_NO_FLUSH, have;
	unsigned char zlib_out[CHUNK];
	char *buf_in = *buffer, *buf_out = NULL;

	if (params->compress == 0)
		return block_len;

	/* allocate deflate state, compress each block independently */
	strm.zalloc = Z_NULL;
	strm.zfree = Z_NULL;
	strm.opaque = Z_NULL;
	strm.avail_in = 0;
	strm.next_in = Z_NULL;
	if (deflateInit(&strm, Z_DEFAULT_COMPRESSION) != Z_OK) {
		error("File compression configuration error, sending uncompressed file");
		params->compress = 0;
		return block_len;
	}

	buf_out_size = block_len + 1024;
	buf_out = xmalloc(buf_out_size);
	while (block_len > buf_in_offset) {
		strm.next_in = (unsigned char *) buf_in + buf_in_offset;
		strm.avail_in = MIN(CHUNK, block_len - buf_in_offset);
		buf_in_offset += strm.avail_in;
		if (buf_in_offset >= block_len)
			flush = Z_FINISH;
		do {
			strm.avail_out = CHUNK;
			strm.next_out = zlib_out;
			if (deflate(&strm, flush) == Z_STREAM_ERROR)
				fatal("Error compressing file");
			have = CHUNK - strm.avail_out;
			if (buf_out_offset + have >= buf_out_size) {
				buf_out_size += have;
				buf_out = xrealloc(buf_out, buf_out_size);
			}
			memcpy(buf_out + buf_out_offset, zlib_out, have);
			buf_out_offset += have;
		} while (strm.avail_out == 0);
		if (strm.avail_in != 0)
			fatal("Failed to compress input buffer");
	}
	(void)deflateEnd(&strm);
	xfree(*buffer);
	*buffer = buf_out;
	return buf_out_offset;
#else
	if (params->compress != 0) {
		info("File compression not supported, sending uncompressed file");
		params->compress = 0;
	}
	return block_len;
#endif
}

/* read and broadcast the file */
static int _bcast_file(struct bcast_parameters *params)
{
	int buf_size, rc = SLURM_SUCCESS;
	ssize_t size_read = 0;
	file_bcast_msg_t bcast_msg;
	char *buffer;
	int32_t block_len;
	uint32_t size_uncompressed = 0, size_compressed = 0;
	uint32_t time_compression = 0;
	DEF_TIMERS;

	if (params->block_size)
		buf_size = MIN(params->block_size, f_stat.st_size);
	else
		buf_size = MIN((512 * 1024), f_stat.st_size);

	bzero(&bcast_msg, sizeof(file_bcast_msg_t));
	bcast_msg.fname		= params->dst_fname;
	bcast_msg.block_no	= 1;
	bcast_msg.force		= params->force;
	bcast_msg.modes		= f_stat.st_mode;
	bcast_msg.uid		= f_stat.st_uid;
	bcast_msg.user_name	= uid_to_string(f_stat.st_uid);
	bcast_msg.gid		= f_stat.st_gid;
	buffer			= xmalloc(buf_size);
	bcast_msg.cred          = sbcast_cred->sbcast_cred;

	if (params->preserve) {
		bcast_msg.atime     = f_stat.st_atime;
		bcast_msg.mtime     = f_stat.st_mtime;
	}

	if (!params->fanout)
		params->fanout = MAX_THREADS;
	slurm_set_tree_width(MIN(MAX_THREADS, params->fanout));

	while (1) {
		block_len = _get_block(params, buffer, buf_size);
		if (block_len < 0)
			rc = SLURM_ERROR;
		if (block_len <= 0)
			break;
		START_TIMER;
		bcast_msg.block_len = _compress_data(params, &buffer,block_len);
		END_TIMER;
		time_compression += DELTA_TIMER;
		size_uncompressed += block_len;
		size_compressed += bcast_msg.block_len;
		debug("block %d, size %u", bcast_msg.block_no,
		      bcast_msg.block_len);
		if (params->compress)
			bcast_msg.compress = 1;
		bcast_msg.block = buffer;
		size_read += block_len;
		if (size_read >= f_stat.st_size)
			bcast_msg.last_block = 1;

		rc = _file_bcast(params, &bcast_msg, sbcast_cred);
		if (rc != SLURM_SUCCESS)
			break;
		if (bcast_msg.last_block)
			break;	/* end of file */
		bcast_msg.block_no++;
	}
	xfree(bcast_msg.user_name);
	xfree(buffer);

	if (size_uncompressed && params->compress != 0) {
		int64_t pct = (int64_t) size_uncompressed - size_compressed;
		/* Dividing a negative by a positive in C99 results in
		 * "truncation towards zero" which gives unexpected values for
		 * pct. This construct avoids that problem.
		 */
		pct = (pct>=0) ? pct * 100 / size_uncompressed
			       : - (-pct * 100 / size_uncompressed);
		verbose("File compressed from %u to %u (%d percent) in %u usec",
			size_uncompressed, size_compressed, (int) pct,
			time_compression);
	}

	return rc;
}

extern int bcast_file(struct bcast_parameters *params)
{
	int rc;

	if ((rc = _file_state(params)) != SLURM_SUCCESS)
		return rc;
	if ((rc = _get_job_info(params)) != SLURM_SUCCESS)
		return rc;
	if ((rc = _bcast_file(params)) != SLURM_SUCCESS)
		return rc;

/*	slurm_free_sbcast_cred_msg(sbcast_cred); */
	return rc;
}
