/**
* (non-PHPdoc)
* @see util/Phirehose::log()
*/
protected function log($message)
{
if (!isset($this->db)) {
$this->db = Storage::getDatabase();
}
$this->db->log('Phirehose', $message);
}
/**
* @see Action::run()
*/
public function run()
{
$this->db = Storage::getDatabase();
// First, figure out how many tweets there are in the whole database.
$query = 'SELECT COUNT(*) FROM `' . DB_NAME . '`.`' . POST_TABLE . '`';
$this->db->setQuery($query);
$result = $this->db->query();
$numPosts = $result[0]['COUNT(*)'];
$toDelete = 0;
if ($this->maxAllowed > 0) {
if ($this->maxAllowed > $numPosts) {
return parent::SUCCESS;
}
$toDelete = $numPosts - $this->maxAllowed;
} else {
if ($this->number > 0) {
if ($this->number > $numPosts) {
return parent::SUCCESS;
}
// Delete this number of posts.
$toDelete = $this->number;
} else {
$toDelete = intval($this->percent * (double) $numPosts);
}
}
$query = 'DELETE FROM `' . DB_NAME . '`.`' . POST_TABLE . '` ORDER BY ' . '`date_saved` ASC LIMIT ' . $toDelete;
$this->db->setQuery($query);
$this->db->query();
$this->db->log($this->getName(), $toDelete . ' tweet' . ($toDelete != 1 ? 's' : '') . ' deleted!');
return parent::SUCCESS;
}
/**
* Overridden from parent class' declaration. Since this action relies
* on a probability distribution to determine its next firing, it is not
* a simple addition of terms. Thus, for this class, the "frequency" field
* is ignored and replaced with "delayMean" and "delayVar".
*
* @see Action::setNextAttempt()
*/
public function setNextAttempt()
{
$mean = floatval($this->delayMean);
$var = floatval($this->delayVar);
$rand1 = floatval(mt_rand()) / floatval(mt_getrandmax());
$rand2 = floatval(mt_rand()) / floatval(mt_getrandmax());
// sample from a normal (gaussian) distribution
$delay = intval(sqrt(-2 * log($rand1)) * cos(2 * pi() * $rand2) * $var + $mean);
if ($delay <= 0) {
$delay = 1;
}
// sanity check
$this->nextAttempt = time() + intval($delay * 60);
// log the next attempt
$this->db = Storage::getDatabase();
$this->db->log($this->getName(), 'Next action firing set for ' . date('Y-m-d H:i:s', $this->nextAttempt));
unset($this->db);
}
<?php
define('TWITTERBOT', 1);
// script for installing the twitterbot's SQL back-end
// NOTE: only run this AFTER setting up config.php!
include_once 'config.php';
include_once 'action.php';
include_once 'storage.php';
// first, set up any tables needed for the core install
$db = Storage::getDatabase();
$sql = 'CREATE TABLE IF NOT EXISTS `' . DB_NAME . '`.`' . POST_TABLE . '` (' . '`postid` INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY ,' . '`text` VARCHAR( 140 ) NOT NULL ,' . '`user` VARCHAR( 50 ) NOT NULL ,' . '`date_saved` DATETIME NOT NULL ,' . '`modeled` SMALLINT NOT NULL DEFAULT \'0\')';
$db->setQuery($sql);
$db->query();
$sql = 'CREATE TABLE IF NOT EXISTS `' . DB_NAME . '`.`' . LOG_TABLE . '` (' . '`eventid` INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY ,' . '`eventtime` DATETIME NOT NULL ,' . '`message` TEXT NOT NULL)';
$db->setQuery($sql);
$db->query();
/**
* Signal handler for child processes that have exited via SIGCHLD.
* @param int $signal
*/
private function sig_child($signal)
{
$status = Action::FAILURE;
while (($pid = pcntl_wait($status, WNOHANG)) > 0) {
$action = $this->current[$pid];
unset($this->current[$pid]);
if (pcntl_wifexited($status) && pcntl_wexitstatus($status) == Action::SUCCESS) {
$status = Action::SUCCESS;
}
if ($action != $this->aggregator) {
$action->post_run($status);
} else {
// the aggregator failed! this is a problem
$db = Storage::getDatabase();
$db->log('Twitterbot', 'Aggregator crashed! Exiting.');
unset($db);
exit;
}
}
}
/**
* This method can be called after the run() method to perform
* post-processing.
*
* In this case, it logs any failures (if the run() return value is
* Action::FAILURE) and saves the necessary values to the database.
* @param int $status The return code from the child process exiting.
*/
public function post_run($status)
{
$this->db = Storage::getDatabase();
// log the status of this action
if ($status !== $this->currentStatus) {
$this->previousStatus = $this->currentStatus;
}
if ($status === self::FAILURE) {
if ($this->currentStatus === self::FAILURE) {
// failed consecutive times
$this->db->log($this->name, "Still have not recovered from previous" . "error!");
} else {
// this is the first time the action has failed
$this->db->log($this->name, "Error has occurred!");
}
} else {
// Action::SUCCESS. Log this only if the previous status
// was Action::FAILURE, so we know we've recovered from something.
if ($this->previousStatus === Action::FAILURE) {
$this->db->log($this->name, "Recovered from previous failure.");
} else {
$this->db->log($this->name, "Successful run!");
}
}
// set the current status
$this->currentStatus = $status;
// destroy the database connection
unset($this->db);
}
