class.tx_scheduler_croncmd.php

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<?php
/***************************************************************
 *  Copyright notice
 *
 *  (c) 2008-2011 Markus Friedrich (markus.friedrich@dkd.de)
 *  All rights reserved
 *
 *  This script is part of the TYPO3 project. The TYPO3 project 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.
 *
 *  The GNU General Public License can be found at
 *  http://www.gnu.org/copyleft/gpl.html.
 *
 *  This script 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.
 *
 *  This copyright notice MUST APPEAR in all copies of the script!
 ***************************************************************/

/**
 * This class provides calulations for the cron command format.
 *
 * @author Markus Friedrich <markus.friedrich@dkd.de>
 * @author Christian Kuhn <lolli@schwarzbu.ch>
 * @package TYPO3
 * @subpackage tx_scheduler
 */
class tx_scheduler_CronCmd {

    /**
     * Normalized sections of the cron command.
     * Allowed are comma separated lists of integers and the character '*'
     *
     *  field          lower and upper bound
     *  -----          --------------
     *  minute         0-59
     *  hour           0-23
     *  day of month   1-31
     *  month          1-12
     *  day of week    1-7
     *
     * @var array $cronCommandSections
     */
    protected $cronCommandSections;

    /**
     * Timestamp of next execution date.
     * This value starts with 'now + 1 minute' if not set externally
     * by unit tests. After a call to calculateNextValue() it holds the timestamp of
     * the next execution date which matches the cron command restrictions.
     */
    protected $timestamp;

    /**
     * Constructor
     *
     * @api
     * @param string $cronCommand: The cron command can hold any combination documented as valid
     *      expression in usual unix like crons like vixiecron. Special commands like @weekly,
     *      ranges, steps and three letter month and weekday abbreviations are allowed.
     * @param integer $timestamp: optional start time, used in unit tests
     * @return void
     */
    public function __construct($cronCommand, $timestamp = FALSE) {
        $cronCommand = tx_scheduler_CronCmd_Normalize::normalize($cronCommand);

            // Explode cron command to sections
        $this->cronCommandSections = t3lib_div::trimExplode(' ', $cronCommand);

            // Initialize the values with the starting time
            // This takes care that the calculated time is always in the future
        if ($timestamp === FALSE) {
            $timestamp = strtotime('+1 minute');
        } else {
            $timestamp += 60;
        }
        $this->timestamp = $this->roundTimestamp($timestamp);
    }

    /**
     * Calulates the date of the next execution.
     *
     * @api
     * @param integer $level (Deprecated) Number of the current level, e.g. 2 is the day level
     * @return void
     */
    public function calculateNextValue($level = NULL) {
        if (!is_null($level)) {
            t3lib_div::deprecationLog('The parameter $level is deprecated since TYPO3 version 4.5.');
        }

        $newTimestamp = $this->getTimestamp();

            // Calculate next minute and hour field
        $loopCount = 0;
        while (TRUE) {
            $loopCount ++;
                // If there was no match within two days, cron command is invalid.
                // The second day is needed to catch the summertime leap in some countries.
            if ($loopCount > 2880) {
                throw new RuntimeException(
                    'Unable to determine next execution timestamp: Hour and minute combination is invalid.',
                    1291494126
                );
            }
            if ($this->minuteAndHourMatchesCronCommand($newTimestamp)) {
                break;
            }
            $newTimestamp += 60;
        }

        $loopCount = 0;
        while (TRUE) {
            $loopCount ++;
                // A date must match within the next 4 years, this high number makes
                // sure leap year cron command configuration are caught.
                // If the loop runs longer than that, the cron command is invalid.
            if ($loopCount > 1464) {
                throw new RuntimeException(
                    'Unable to determine next execution timestamp: Day of month, month and day of week combination is invalid.',
                    1291501280
                );
            }
            if ($this->dayMatchesCronCommand($newTimestamp)) {
                break;
            }
            $newTimestamp += $this->numberOfSecondsInDay($newTimestamp);
        }

        $this->timestamp = $newTimestamp;
    }

    /*
     * Get next timestamp
     *
     * @api
     * @return integer Unix timestamp
     */
    public function getTimestamp() {
        return $this->timestamp;
    }

    /**
     * Get cron command sections. Array of strings, each containing either
     * a list of comma seperated integers or *
     *
     * @return array command sections:
     *  0 => minute
     *  1 => hour
     *  2 => day of month
     *  3 => month
     *  4 => day of week
     */
    public function getCronCommandSections() {
        return $this->cronCommandSections;
    }

    /**
     * Determine if current timestamp matches minute and hour cron command restriction.
     *
     * @param integer $timestamp to test
     * @return boolean TRUE if cron command conditions are met
     */
    protected function minuteAndHourMatchesCronCommand($timestamp) {
        $minute = intval(date('i', $timestamp));
        $hour = intval(date('G', $timestamp));

        $commandMatch = FALSE;
        if (
            $this->isInCommandList($this->cronCommandSections[0], $minute)
            && $this->isInCommandList($this->cronCommandSections[1], $hour)
        ) {
            $commandMatch = TRUE;
        }

        return $commandMatch;
    }

    /**
     * Determine if current timestamp matches day of month, month and day of week
     * cron command restriction
     *
     * @param integer $timestamp to test
     * @return boolean TRUE if cron command conditions are met
     */
    protected function dayMatchesCronCommand($timestamp) {
        $dayOfMonth = date('j', $timestamp);
        $month = date('n', $timestamp);
        $dayOfWeek = date('N', $timestamp);

        $isInDayOfMonth = $this->isInCommandList($this->cronCommandSections[2], $dayOfMonth);
        $isInMonth = $this->isInCommandList($this->cronCommandSections[3], $month);
        $isInDayOfWeek = $this->isInCommandList($this->cronCommandSections[4], $dayOfWeek);

            // Quote from vixiecron:
            // Note: The day of a command's execution can be specified by two fields — day of month, and day of week.
            // If both fields are restricted (i.e., aren't  *),  the  command will be run when either field
            // matches the current time.  For example, `30 4 1,15 * 5' would cause
            // a command to be run at 4:30 am on the 1st and 15th of each month, plus every Friday.

        $isDayOfMonthRestricted = (string)$this->cronCommandSections[2] ===  '*' ? FALSE : TRUE;
        $isDayOfWeekRestricted = (string)$this->cronCommandSections[4] === '*' ? FALSE : TRUE;

        $commandMatch = FALSE;
        if ($isInMonth) {
            if (
                ($isInDayOfMonth && $isDayOfMonthRestricted)
                || ($isInDayOfWeek && $isDayOfWeekRestricted)
                || ($isInDayOfMonth && !$isDayOfMonthRestricted && $isInDayOfWeek && !$isDayOfWeekRestricted)
            ) {
                $commandMatch = TRUE;
            }
        }

        return $commandMatch;
    }

    /**
     * Determine if a given number validates a cron command section. The given cron
     * command must be a 'normalized' list with only comma separated integers or '*'
     *
     * @param string $commandExpression: cron command
     * @param integer $numberToMatch: number to look up
     * @return boolean TRUE if number is in list
     */
    protected function isInCommandList($commandExpression, $numberToMatch) {
        $inList = FALSE;
        if ((string)$commandExpression === '*') {
            $inList = TRUE;
        } else {
            $inList = t3lib_div::inList($commandExpression, $numberToMatch);
        }

        return $inList;
    }

    /**
     * Helper method to calculate number of seconds in a day.
     *
     * This is not always 86400 (60*60*24) and depends on the timezone:
     * Some countries like Germany have a summertime / wintertime switch,
     * on every last sunday in march clocks are forwarded by one hour (set from 2:00 to 3:00),
     * and on last sunday of october they are set back one hour (from 3:00 to 2:00).
     * This shortens and lengthens the length of a day by one hour.
     *
     * @param integer timestamp
     * @return integer Number of seconds of day
     */
    protected function numberOfSecondsInDay($timestamp) {
        $now = mktime(0, 0, 0, date('n', $timestamp), date('j', $timestamp), date('Y', $timestamp));
            // Make sure to be in next day, even if day has 25 hours
        $nextDay = $now + 60*60*25;
        $nextDay = mktime(0, 0, 0, date('n', $nextDay), date('j', $nextDay), date('Y', $nextDay));

        return ($nextDay - $now);
    }

    /**
     * Round a timestamp down to full minute.
     *
     * @param integer timestamp
     * @return integer Rounded timestamp
     */
    protected function roundTimestamp($timestamp) {
        return mktime(date('H', $timestamp), date('i', $timestamp), 0, date('n', $timestamp), date('j', $timestamp), date('Y', $timestamp));
    }

    /**
     * Returns the first value that is higher than the current value
     * from a list of possible values.
     *
     * @deprecated since 4.5
     * @param   mixed   $currentValue: the value to be searched in the list
     * @param   array   $listArray: the list of values
     * @return  mixed   The value from the list right after the current value
     */
    public function getNextValue($currentValue, array $listArray) {
        t3lib_div::deprecationLog('The method is deprecated since TYPO3 version 4.5.');

        $next_value = false;

        $numValues = count($listArray);
        for ($i = 0; $i < $numValues; $i++) {
            if ($listArray[$i] > $currentValue) {
                $next_value = $listArray[$i];
                break;
            }
        }

        return $next_value;
    }

    /**
     * Returns the timestamp for the value parts in $this->values.
     *
     * @deprecated since 4.5
     * @return integer unix timestamp
     */
    public function getTstamp() {
        t3lib_div::deprecationLog('The method is deprecated since TYPO3 version 4.5.');
        return $this->getTimestamp();
    }
}

if (defined('TYPO3_MODE') && isset($GLOBALS['TYPO3_CONF_VARS'][TYPO3_MODE]['XCLASS']['ext/scheduler/class.tx_scheduler_croncmd.php'])) {
    include_once($GLOBALS['TYPO3_CONF_VARS'][TYPO3_MODE]['XCLASS']['ext/scheduler/class.tx_scheduler_croncmd.php']);
}