/*************************************************************************/
/* Copyright (c) 2004                                                    */
/* Daniel Sleator, David Temperley, and John Lafferty                    */
/* All rights reserved                                                   */
/*                                                                       */
/* Use of the link grammar parsing system is subject to the terms of the */
/* license set forth in the LICENSE file included with this software,    */
/* and also available at http://www.link.cs.cmu.edu/link/license.html    */
/* This license allows free redistribution and use in source and binary  */
/* forms, with or without modification, subject to certain conditions.   */
/*                                                                       */
/*************************************************************************/

#include <link-grammar/api.h>
#include <time.h>

#if !defined(_WIN32)
   #include <sys/time.h>
   #include <sys/resource.h>
#endif

#if defined(__linux__)
/* based on reading the man page for getrusage on linux, I inferred that
   I needed to include this.  However it doesn't seem to be necessary */
   #include <unistd.h>
#endif

#if defined(__hpux__)
  #include <sys/syscall.h>
  int syscall(int, int, struct rusage *rusage);  /* can't find
													the prototype for this */
  #define getrusage(a, b)  syscall(SYS_GETRUSAGE, (a), (b))
#endif /* __hpux__ */

#if defined(__sun__)
int getrusage(int who, struct rusage *rusage);
/* Declaration missing from sys/resource.h in sun operating systems (?) */
#endif /* __sun__ */

#define MAX_PARSE_TIME_UNLIMITED -1
#define MAX_MEMORY_UNLIMITED ((size_t) -1)

/** returns the current usage time clock in seconds */
static double current_usage_time(void)
{
#if !defined(_WIN32)
	struct rusage u;
	getrusage (RUSAGE_SELF, &u);
	return (u.ru_utime.tv_sec + ((double) u.ru_utime.tv_usec) / 1000000.0);
#else
	return ((double) clock())/CLOCKS_PER_SEC;
#endif
}

Resources resources_create(void)
{
	Resources r;

	r = (Resources) xalloc(sizeof(struct Resources_s));
	r->max_parse_time = MAX_PARSE_TIME_UNLIMITED;
	r->when_created = current_usage_time();
	r->when_last_called = current_usage_time();
	r->time_when_parse_started = current_usage_time();
	r->space_when_parse_started = get_space_in_use();
	r->max_memory = MAX_MEMORY_UNLIMITED;
	r->cumulative_time = 0;
	r->memory_exhausted = FALSE;
	r->timer_expired = FALSE;

	return r;
}

void resources_delete(Resources r)
{
	xfree(r, sizeof(struct Resources_s));
}

void resources_reset(Resources r)
{
	r->when_last_called = r->time_when_parse_started = current_usage_time();
	r->space_when_parse_started = get_space_in_use();
	r->timer_expired = FALSE;
	r->memory_exhausted = FALSE;
}

#if 0
static void resources_reset_time(Resources r)
{
	r->when_last_called = r->time_when_parse_started = current_usage_time();
}
#endif

void resources_reset_space(Resources r)
{
	r->space_when_parse_started = get_space_in_use();
}

int resources_exhausted(Resources r)
{
	if (resources_timer_expired(r)) {
		r->timer_expired = TRUE;
	}
	if (resources_memory_exhausted(r)) {
		r->memory_exhausted = TRUE;
	}
	return (r->timer_expired || r->memory_exhausted);
}

int resources_timer_expired(Resources r)
{
	if (r->max_parse_time == MAX_PARSE_TIME_UNLIMITED) return 0;
	else return (r->timer_expired || 
	     (current_usage_time() - r->time_when_parse_started > r->max_parse_time));
}

int resources_memory_exhausted(Resources r)
{
	if (r->max_memory == MAX_MEMORY_UNLIMITED) return 0;
	else return (r->memory_exhausted || (get_space_in_use() > r->max_memory));
}

/** print out the cpu ticks since this was last called */
static void resources_print_time(int verbosity, Resources r, const char * s)
{
	double new_t;
	new_t = current_usage_time();
	if (verbosity > 1) {
		printf("++++");
		left_print_string(stdout, s,
			"                                     ");
		printf("%7.2f seconds\n", new_t - r->when_last_called);
	}
	r->when_last_called = new_t;
}

/** print out the cpu ticks since this was last called */
static void resources_print_total_time(int verbosity, Resources r)
{
	double new_t;
	new_t = current_usage_time();
	r->cumulative_time += (new_t - r->time_when_parse_started) ;
	if (verbosity > 0) {
		printf("++++");
		left_print_string(stdout, "Time",
		                  "                                           ");
		printf("%7.2f seconds (%.2f total)\n",
			   new_t - r->time_when_parse_started, r->cumulative_time);
	}
	r->time_when_parse_started = new_t;
}

static void resources_print_total_space(int verbosity, Resources r)
{
	if (verbosity > 1) {
		printf("++++");
		left_print_string(stdout, "Total space",
		                  "                                            ");
		printf("%lu bytes (%lu max)\n", 
			(long unsigned int) get_space_in_use(), 
			(long unsigned int) get_max_space_used());
	}
}

void print_time(Parse_Options opts, const char * s)
{
	resources_print_time(opts->verbosity, opts->resources, s);
}

void parse_options_print_total_time(Parse_Options opts)
{
	resources_print_total_time(opts->verbosity, opts->resources);
}

void print_total_space(Parse_Options opts)
{
	resources_print_total_space(opts->verbosity, opts->resources);
}

