#include <sys/types.h>
#include <sys/stat.h>

#include <errno.h>
#include <pthread.h>

// if we're using linux's crazy version of the pthread header, 
// it probably forgot to include PTHREAD_STACK_MIN 

#ifndef PTHREAD_STACK_MIN
#include <limits.h>
#endif

#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <assert.h>
#include <db.h>

#define	ENV_DIRECTORY	"TXNAPP"

#define MAX_SECONDS 100
#define COUNTER_RESOLUTION 240

int buckets[COUNTER_RESOLUTION];

int activeThreads = 0;
int max_active = 0;

pthread_cond_t never;
pthread_mutex_t mutex;


void  run_xact(DB_ENV *, DB *, int, int);
void *checkpoint_thread(void *);
void  log_archlist(DB_ENV *);
void *logfile_thread(void *);
void  db_open(DB_ENV *, DB **, char *, int);
void  env_dir_create(void);
void  env_open(DB_ENV **);
void  usage(void);

DB_ENV *dbenv;
DB *db_cats; /*, *db_color, *db_fruit; */

int num_xact;
int insert_per_xact;
void * runThread(void * arg);
int
main(int argc, char *argv[])
{
	extern int optind;

	pthread_t ptid;
	int ch, ret;

	assert(argc == 3);
	/* threads have static thread sizes.  Ughh. */
	pthread_attr_t attr;
	pthread_attr_init(&attr);
	
	pthread_mutex_init(&mutex, NULL);
	pthread_cond_init(&never, NULL);
  
	pthread_attr_setstacksize (&attr, 4 * PTHREAD_STACK_MIN);
	
	pthread_mutex_lock(&mutex);

	
	int l;
	
	for(l = 0; l < COUNTER_RESOLUTION; l++) {
	  buckets[l] = 0;
	}
	

	env_dir_create();
	env_open(&dbenv);

	/* Start a checkpoint thread. */
	if ((ret = pthread_create(
	    &ptid, &attr, checkpoint_thread, (void *)dbenv)) != 0) {
		fprintf(stderr,
		    "txnapp: failed spawning checkpoint thread: %s\n",
		    strerror(ret));
		exit (1);
	}

	/* Start a logfile removal thread. */
	if ((ret = pthread_create(
	    &ptid, &attr, logfile_thread, (void *)dbenv)) != 0) {
		fprintf(stderr,
		    "txnapp: failed spawning log file removal thread: %s\n",
		    strerror(ret));
		exit (1);
	}

	/* Open database: Key is fruit class; Data is specific type. */
	/*	db_open(dbenv, &db_fruit, "fruit", 0); */

	/* Open database: Key is a color; Data is an integer. */
	/*db_open(dbenv, &db_color, "color", 0); */

	/*
	 * Open database:
	 *	Key is a name; Data is: company name, address, cat breeds.
	 */
	db_open(dbenv, &db_cats, "cats", 1);

	int r;
	int num_threads         = atoi(argv[1]);

	num_xact = 1;
	insert_per_xact = atoi(argv[2]);

	pthread_t * threads = malloc(num_threads * sizeof(pthread_t));
	int i ;
	for(i = 0; i < num_threads; i++) {

	  if ((ret = pthread_create(&(threads[i]), &attr, runThread, (void *)i)) != 0){
	    fprintf(stderr,
		    "txnapp: failed spawning worker thread: %s\n",
		    strerror(ret));
	    exit (1);
	  }

	}     
	
	pthread_mutex_unlock(&mutex);

	for(i = 0; i < num_threads; i++) {
	  pthread_join(threads[i], NULL);
	}

	free(threads);

	int k;
	double log_multiplier = (COUNTER_RESOLUTION / log(MAX_SECONDS * 1000000000.0));
	for(k = 0; k < COUNTER_RESOLUTION; k++) {
	  printf("%3.4f\t%d\n", exp(((double)k)/log_multiplier)/1000000000.0, buckets[k]);
	}

	return (0);
}


void * runThread(void * arg) {
  int offset = (int) arg;
  
  pthread_mutex_lock(&mutex);
  activeThreads++;
  if(activeThreads > max_active) {
    max_active = activeThreads;
  }
  pthread_mutex_unlock(&mutex);


  int r;

  double sum_x_squared = 0;
  double sum = 0;

  double log_multiplier = COUNTER_RESOLUTION / log(MAX_SECONDS * 1000000000.0);

  struct timeval timeout_tv;
  struct timespec timeout;

  gettimeofday(&timeout_tv, NULL);

  timeout.tv_sec = timeout_tv.tv_sec;
  timeout.tv_nsec = 1000 * timeout_tv.tv_usec;

  timeout.tv_nsec = (int)(1000000000.0 * ((double)random() / (double)RAND_MAX));

  timeout.tv_sec++;

  //  struct timeval start;

  pthread_mutex_lock(&mutex);
  pthread_cond_timedwait(&never, &mutex, &timeout);
  pthread_mutex_unlock(&mutex);
  

  for(r = 0; r < num_xact; r ++) {

    struct timeval endtime_tv;
    struct timespec endtime;

    run_xact(dbenv, db_cats, offset*(1+r)*insert_per_xact, insert_per_xact);

   gettimeofday(&endtime_tv, NULL);

    endtime.tv_sec = endtime_tv.tv_sec;
    endtime.tv_nsec = 1000 * endtime_tv.tv_usec;

    double microSecondsPassed = 1000000000.0 * (double)(endtime.tv_sec - timeout.tv_sec);


    microSecondsPassed = (microSecondsPassed + (double)endtime.tv_nsec) - (double)timeout.tv_nsec;

    assert(microSecondsPassed > 0.0);


    sum += microSecondsPassed;
    sum_x_squared += (microSecondsPassed * microSecondsPassed) ;

    int bucket = (log_multiplier * log(microSecondsPassed));
    
    if(bucket >= COUNTER_RESOLUTION) { bucket = COUNTER_RESOLUTION - 1; }
    
    timeout.tv_sec++;
    pthread_mutex_lock(&mutex);
    buckets[bucket]++;
    pthread_cond_timedwait(&never, &mutex, &timeout);
    pthread_mutex_unlock(&mutex);

  }

  pthread_mutex_lock(&mutex);
  activeThreads--;
  pthread_mutex_unlock(&mutex);


  //  printf("%d done\n", offset);
}


void
env_dir_create()
{
	struct stat sb;

	/*
	 * If the directory exists, we're done.  We do not further check
	 * the type of the file, DB will fail appropriately if it's the
	 * wrong type.
	 */
	if (stat(ENV_DIRECTORY, &sb) == 0)
		return;

	/* Create the directory, read/write/access owner only. */
	if (mkdir(ENV_DIRECTORY, S_IRWXU) != 0) {
		fprintf(stderr,
		    "txnapp: mkdir: %s: %s\n", ENV_DIRECTORY, strerror(errno));
		exit (1);
	}
}

void
env_open(DB_ENV **dbenvp)
{
	DB_ENV *dbenv;
	int ret;

	/* Create the environment handle. */
	if ((ret = db_env_create(&dbenv, 0)) != 0) {
		fprintf(stderr,
		    "txnapp: db_env_create: %s\n", db_strerror(ret));
		exit (1);
	}

	/* Set up error handling. */
	dbenv->set_errpfx(dbenv, "txnapp");
	dbenv->set_errfile(dbenv, stderr);

	/* Do deadlock detection internally. */
	if ((ret = dbenv->set_lk_detect(dbenv, DB_LOCK_DEFAULT)) != 0) {
		dbenv->err(dbenv, ret, "set_lk_detect: DB_LOCK_DEFAULT");
		exit (1);
	}

	/*
	 * Open a transactional environment:
	 *	create if it doesn't exist
	 *	free-threaded handle
	 *	run recovery
	 *	read/write owner only
	 */
	if ((ret = dbenv->open(dbenv, ENV_DIRECTORY,
	    DB_CREATE | DB_INIT_LOCK | DB_INIT_LOG |
	    DB_INIT_MPOOL | DB_INIT_TXN | DB_RECOVER | DB_THREAD,
	    S_IRUSR | S_IWUSR)) != 0) {
		dbenv->err(dbenv, ret, "dbenv->open: %s", ENV_DIRECTORY);
		exit (1);
	}

	*dbenvp = dbenv;
}

void *
checkpoint_thread(void *arg)
{
	DB_ENV *dbenv;
	int ret;

	dbenv = arg;
	dbenv->errx(dbenv, "Checkpoint thread: %lu", (u_long)pthread_self());

	/* Checkpoint once a minute. */
	for (;; sleep(60))
		if ((ret = dbenv->txn_checkpoint(dbenv, 0, 0, 0)) != 0) {
			dbenv->err(dbenv, ret, "checkpoint thread");
			exit (1);
		}

	/* NOTREACHED */
}

void *
logfile_thread(void *arg)
{
	DB_ENV *dbenv;
	int ret;
	char **begin, **list;

	dbenv = arg;
	dbenv->errx(dbenv,
	    "Log file removal thread: %lu", (u_long)pthread_self());

	/* Check once every 5 minutes. */
	for (;; sleep(300)) {
		/* Get the list of log files. */
		if ((ret =
		    dbenv->log_archive(dbenv, &list, DB_ARCH_ABS)) != 0) {
			dbenv->err(dbenv, ret, "DB_ENV->log_archive");
			exit (1);
		}

		/* Remove the log files. */
		if (list != NULL) {
			for (begin = list; *list != NULL; ++list)
				if ((ret = remove(*list)) != 0) {
					dbenv->err(dbenv,
					    ret, "remove %s", *list);
					exit (1);
				}
			free (begin);
		}
	}
	/* NOTREACHED */
}

void
log_archlist(DB_ENV *dbenv)
{
	int ret;
	char **begin, **list;

	/* Get the list of database files. */
	if ((ret = dbenv->log_archive(dbenv,
	    &list, DB_ARCH_ABS | DB_ARCH_DATA)) != 0) {
		dbenv->err(dbenv, ret, "DB_ENV->log_archive: DB_ARCH_DATA");
		exit (1);
	}
	if (list != NULL) {
		for (begin = list; *list != NULL; ++list)
			printf("database file: %s\n", *list);
		free (begin);
	}

	/* Get the list of log files. */
	if ((ret = dbenv->log_archive(dbenv,
	    &list, DB_ARCH_ABS | DB_ARCH_LOG)) != 0) {
		dbenv->err(dbenv, ret, "DB_ENV->log_archive: DB_ARCH_LOG");
		exit (1);
	}
	if (list != NULL) {
		for (begin = list; *list != NULL; ++list)
			printf("log file: %s\n", *list);
		free (begin);
	}
}

void
db_open(DB_ENV *dbenv, DB **dbp, char *name, int dups)
{
	DB *db;
	int ret;

	/* Create the database handle. */
	if ((ret = db_create(&db, dbenv, 0)) != 0) {
		dbenv->err(dbenv, ret, "db_create");
		exit (1);
	}

	/* Optionally, turn on duplicate data items. */
	/*	if (dups && (ret = db->set_flags(db, DB_DUP)) != 0) {
		dbenv->err(dbenv, ret, "db->set_flags: DB_DUP");
		exit (1);
		} */

	/*
	 * Open a database in the environment:
	 *	create if it doesn't exist
	 *	free-threaded handle
	 *	read/write owner only
	 */
	if ((ret = db->open(db, NULL, name, NULL, /*DB_BTREE*//* DB_RECNO */DB_HASH,
			    DB_AUTO_COMMIT | DB_DIRTY_READ | DB_TXN_SYNC | DB_CREATE | DB_THREAD, S_IRUSR | S_IWUSR)) != 0) {
		(void)db->close(db, 0);
		dbenv->err(dbenv, ret, "db->open: %s", name);
		exit (1);
	}

	*dbp = db;
}

void
run_xact(DB_ENV *dbenv, DB *db, int offset, int count)
{
  //	va_list ap;
	DBC *dbc;
	DBT key, data;
	DB_TXN *tid;
	int ret;
	char *s;

	/* Initialization. */
	memset(&key, 0, sizeof(key));
	memset(&data, 0, sizeof(data));
	int keyPtr;
	int valPtr;
	key.data = &keyPtr;
	key.size = sizeof(int);/*strlen(name);*/
	data.data = &valPtr;
	data.size = sizeof(int);

retry:	/* Begin the transaction. */
	if ((ret = dbenv->txn_begin(dbenv, NULL, &tid, 0)) != 0) {
		dbenv->err(dbenv, ret, "DB_ENV->txn_begin");
		exit (1);
	}

	/* Create a cursor. */
	if ((ret = db->cursor(db, tid, &dbc, 0)) != 0) {
		dbenv->err(dbenv, ret, "db->cursor");
		exit (1);
	}

	int q;
	/* Count is one for this test */
	assert(count == 1);

	for(q = offset; q < offset + count; q++) {
	  keyPtr = q;
	  valPtr = q;

		switch (ret = dbc->c_put(dbc, &key, &data, DB_KEYLAST)) {
		case 0:
		  break;
		case DB_LOCK_DEADLOCK:
		  //		  va_end(ap);
		  abort();  // Locking should be disabled!
		  /* Deadlock: retry the operation. */
		  if ((ret = dbc->c_close(dbc)) != 0) {
		    dbenv->err(
			       dbenv, ret, "dbc->c_close");
		    exit (1);
		  }
		  if ((ret = tid->abort(tid)) != 0) {
		    dbenv->err(dbenv, ret, "DB_TXN->abort");
		    exit (1);
		  }
		  goto retry;
		default:
		  abort();  // Error invalidates benchmark!
		  /* Error: run recovery. */
		  dbenv->err(dbenv, ret, "dbc->put: %d/%d", q, q);
		  exit (1);
		}
	}

	/* Success: commit the change. */
	if ((ret = dbc->c_close(dbc)) != 0) {
		dbenv->err(dbenv, ret, "dbc->c_close");
		exit (1);
	}
	if ((ret = tid->commit(tid, 0)) != 0) {
		dbenv->err(dbenv, ret, "DB_TXN->commit");
		exit (1);
	}
}

void
usage()
{
	(void)fprintf(stderr, "usage: txnapp\n");
	exit(1);
}