Your IP : 192.168.165.1
<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle 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 3 of the License, or
// (at your option) any later version.
//
// Moodle 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 Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* @package moodlecore
* @subpackage backup-helper
* @copyright 2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
/**
* Helper class used to restore logs, converting all the information as needed
*
* This class allows each restore task to specify which logs (by action) will
* be handled on restore and which transformations will be performed in order
* to accomodate them into their new destination
*
* TODO: Complete phpdocs
*/
class restore_log_rule implements processable {
protected $module; // module of the log record
protected $action; // action of the log record
protected $urlread; // url format of the log record in backup file
protected $inforead; // info format of the log record in backup file
protected $modulewrite;// module of the log record to be written (defaults to $module if not specified)
protected $actionwrite;// action of the log record to be written (defaults to $action if not specified)
protected $urlwrite; // url format of the log record to be written (defaults to $urlread if not specified)
protected $infowrite;// info format of the log record to be written (defaults to $inforead if not specified)
protected $urlreadregexp; // Regexps for extracting information from url and info
protected $inforeadregexp;
protected $allpairs; // to acummulate all tokens and values pairs on each log record restored
protected $urltokens; // tokens present int the $urlread attribute
protected $infotokens;// tokens present in the $inforead attribute
protected $fixedvalues; // Some values that will have precedence over mappings to save tons of DB mappings
protected $restoreid;
public function __construct($module, $action, $urlread, $inforead,
$modulewrite = null, $actionwrite = null, $urlwrite = null, $infowrite = null) {
$this->module = $module;
$this->action = $action;
$this->urlread = $urlread;
$this->inforead = $inforead;
$this->modulewrite = is_null($modulewrite) ? $module : $modulewrite;
$this->actionwrite= is_null($actionwrite) ? $action : $actionwrite;
$this->urlwrite = is_null($urlwrite) ? $urlread : $urlwrite;
$this->infowrite= is_null($infowrite) ? $inforead : $infowrite;
$this->allpairs = array();
$this->urltokens = array();
$this->infotokens= array();
$this->urlreadregexp = null;
$this->inforeadregexp = null;
$this->fixedvalues = array();
$this->restoreid = null;
// TODO: validate module, action are valid => exception
// Calculate regexps and tokens, both for urlread and inforead
$this->calculate_url_regexp($this->urlread);
$this->calculate_info_regexp($this->inforead);
}
public function set_restoreid($restoreid) {
$this->restoreid = $restoreid;
}
public function set_fixed_values($values) {
//TODO: check $values is array => exception
$this->fixedvalues = $values;
}
public function get_key_name() {
return $this->module . '-' . $this->action;
}
public function process($inputlog) {
// There might be multiple rules that process this log, we can't alter it in the process of checking it.
$log = clone($inputlog);
// Reset the allpairs array
$this->allpairs = array();
$urlmatches = array();
$infomatches = array();
// Apply urlreadregexp to the $log->url if necessary
if ($this->urlreadregexp) {
preg_match($this->urlreadregexp, $log->url, $urlmatches);
if (empty($urlmatches)) {
return false;
}
} else {
if (!is_null($this->urlread)) { // If not null, use it (null means unmodified)
$log->url = $this->urlread;
}
}
// Apply inforeadregexp to the $log->info if necessary
if ($this->inforeadregexp) {
preg_match($this->inforeadregexp, $log->info, $infomatches);
if (empty($infomatches)) {
return false;
}
} else {
if (!is_null($this->inforead)) { // If not null, use it (null means unmodified)
$log->info = $this->inforead;
}
}
// If there are $urlmatches, let's process them
if (!empty($urlmatches)) {
array_shift($urlmatches); // Take out first element
if (count($urlmatches) !== count($this->urltokens)) { // Number of matches must be number of tokens
return false;
}
// Let's process all the tokens and matches, using them to parse the urlwrite
$log->url = $this->parse_tokens_and_matches($this->urltokens, $urlmatches, $this->urlwrite);
}
// If there are $infomatches, let's process them
if (!empty($infomatches)) {
array_shift($infomatches); // Take out first element
if (count($infomatches) !== count($this->infotokens)) { // Number of matches must be number of tokens
return false;
}
// Let's process all the tokens and matches, using them to parse the infowrite
$log->info = $this->parse_tokens_and_matches($this->infotokens, $infomatches, $this->infowrite);
}
// Arrived here, if there is any pending token in $log->url or $log->info, stop
if ($this->extract_tokens($log->url) || $this->extract_tokens($log->info)) {
return false;
}
// Finally, set module and action
$log->module = $this->modulewrite;
$log->action = $this->actionwrite;
return $log;
}
// Protected API starts here
protected function parse_tokens_and_matches($tokens, $values, $content) {
$pairs = array_combine($tokens, $values);
ksort($pairs); // First literals, then mappings
foreach ($pairs as $token => $value) {
// If one token has already been processed, continue
if (array_key_exists($token, $this->allpairs)) {
continue;
}
// If the pair is one literal token, just keep it unmodified
if (substr($token, 0, 1) == '[') {
$this->allpairs[$token] = $value;
// If the pair is one mapping token, let's process it
} else if (substr($token, 0, 1) == '{') {
$ctoken = $token;
// First, resolve mappings to literals if necessary
if (substr($token, 1, 1) == '[') {
$literaltoken = trim($token, '{}');
if (array_key_exists($literaltoken, $this->allpairs)) {
$ctoken = '{' . $this->allpairs[$literaltoken] . '}';
}
}
// Look for mapping in fixedvalues before going to DB
$plaintoken = trim($ctoken, '{}');
if (array_key_exists($plaintoken, $this->fixedvalues)) {
$this->allpairs[$token] = $this->fixedvalues[$plaintoken];
// Last chance, fetch value from backup_ids_temp, via mapping
} else {
if ($mapping = restore_dbops::get_backup_ids_record($this->restoreid, $plaintoken, $value)) {
$this->allpairs[$token] = $mapping->newitemid;
}
}
}
}
// Apply all the conversions array (allpairs) to content
krsort($this->allpairs); // First mappings, then literals
$content = str_replace(array_keys($this->allpairs), $this->allpairs, $content);
return $content;
}
protected function calculate_url_regexp($urlexpression) {
// Detect all the tokens in the expression
if ($tokens = $this->extract_tokens($urlexpression)) {
$this->urltokens = $tokens;
// Now, build the regexp
$this->urlreadregexp = $this->build_regexp($urlexpression, $this->urltokens);
}
}
protected function calculate_info_regexp($infoexpression) {
// Detect all the tokens in the expression
if ($tokens = $this->extract_tokens($infoexpression)) {
$this->infotokens = $tokens;
// Now, build the regexp
$this->inforeadregexp = $this->build_regexp($infoexpression, $this->infotokens);
}
}
protected function extract_tokens($expression) {
// Extract all the tokens enclosed in square and curly brackets
preg_match_all('~\[[^\]]+\]|\{[^\}]+\}~', $expression, $matches);
return $matches[0];
}
protected function build_regexp($expression, $tokens) {
// Replace to temp (and preg_quote() safe) placeholders
foreach ($tokens as $token) {
$expression = preg_replace('~' . preg_quote($token, '~') . '~', '%@@%@@%', $expression, 1);
}
// quote the expression
$expression = preg_quote($expression, '~');
// Replace all the placeholders
$expression = preg_replace('~%@@%@@%~', '(.*)', $expression);
return '~' . $expression . '~';
}
}