Proyectos de Subversion Moodle

<?php

/**

 * Library for CSV serialization.

 *

 * This is used by the csv/proxy driver and is the CacheExecute()

 * serialization format.

 *

 * This file is part of ADOdb, a Database Abstraction Layer library for PHP.

 *

 * @package ADOdb

 * @link https://adodb.org Project's web site and documentation

 * @link https://github.com/ADOdb/ADOdb Source code and issue tracker

 *

 * The ADOdb Library is dual-licensed, released under both the BSD 3-Clause

 * and the GNU Lesser General Public Licence (LGPL) v2.1 or, at your option,

 * any later version. This means you can use it in proprietary products.

 * See the LICENSE.md file distributed with this source code for details.

 * @license BSD-3-Clause

 * @license LGPL-2.1-or-later

 *

 * @copyright 2000-2013 John Lim

 * @copyright 2014 Damien Regad, Mark Newnham and the ADOdb community

 */

// security - hide paths

if (!defined('ADODB_DIR')) die();

global $ADODB_INCLUDED_CSV;

$ADODB_INCLUDED_CSV = 1;

	/**

 	 * Convert a recordset into special format

	 *

	 * @param ADORecordSet  $rs the recordset

	 * @param ADOConnection $conn

	 * @param string        $sql

	 *

	 * @return string the CSV formatted data

	 */

	function _rs2serialize(&$rs,$conn=false,$sql='')

	{

		$max = ($rs) ? $rs->FieldCount() : 0;

		if ($sql) $sql = urlencode($sql);

		// metadata setup

		if ($max <= 0 || $rs->dataProvider == 'empty') { // is insert/update/delete

			if (is_object($conn)) {

				$sql .= ','.$conn->Affected_Rows();

				$sql .= ','.$conn->Insert_ID();

			} else

				$sql .= ',,';

			$text = "====-1,0,$sql\n";

			return $text;

		}

		$tt = ($rs->timeCreated) ? $rs->timeCreated : time();

		## changed format from ====0 to ====1

		$line = "====1,$tt,$sql\n";

		if ($rs->databaseType == 'array') {

			$rows = $rs->_array;

		} else {

			$rows = array();

			while (!$rs->EOF) {

				$rows[] = $rs->fields;

				$rs->MoveNext();

			}

		}

		for($i=0; $i < $max; $i++) {

			$o = $rs->FetchField($i);

			$flds[] = $o;

		}

		$savefetch = isset($rs->adodbFetchMode) ? $rs->adodbFetchMode : $rs->fetchMode;

		$class = $rs->connection->arrayClass;

		/** @var ADORecordSet $rs2 */

		$rs2 = new $class(ADORecordSet::DUMMY_QUERY_ID);

		$rs2->timeCreated = $rs->timeCreated; # memcache fix

		$rs2->sql = $rs->sql;

		$rs2->InitArrayFields($rows,$flds);

		$rs2->fetchMode = $savefetch;

		return $line.serialize($rs2);

	}

	/**

	 * Open CSV file and convert it into Data.

	 *

	 * @param string $url     file/ftp/http url

	 * @param string &$err    returns the error message

	 * @param int $timeout    dispose if recordset has been alive for $timeout secs

	 * @param string $rsclass RecordSet class to return

	 *

	 * @return ADORecordSet|false recordset, or false if error occurred.

	 *                            If no error occurred in sql INSERT/UPDATE/DELETE,

	 *                            empty recordset is returned.

	 */

	function csv2rs($url, &$err, $timeout=0, $rsclass='ADORecordSet_array')

	{

		$false = false;

		$err = false;

		$fp = @fopen($url,'rb');

		if (!$fp) {

			$err = $url.' file/URL not found';

			return $false;

		}

		@flock($fp, LOCK_SH);

		$arr = array();

		$ttl = 0;

		if ($meta = fgetcsv($fp, 32000, ",")) {

			// check if error message

			if (strncmp($meta[0],'****',4) === 0) {

				$err = trim(substr($meta[0],4,1024));

				fclose($fp);

				return $false;

			}

			// check for meta data

			// $meta[0] is -1 means return an empty recordset

			// $meta[1] contains a time

			if (strncmp($meta[0], '====',4) === 0) {

				if ($meta[0] == "====-1") {

					if (sizeof($meta) < 5) {

						$err = "Corrupt first line for format -1";

						fclose($fp);

						return $false;

					}

					fclose($fp);

					if ($timeout > 0) {

						$err = " Illegal Timeout $timeout ";

						return $false;

					}

					$rs = new $rsclass($val=true);

					$rs->fields = array();

					$rs->timeCreated = $meta[1];

					$rs->EOF = true;

					$rs->_numOfFields = 0;

					$rs->sql = urldecode($meta[2]);

					$rs->affectedrows = (integer)$meta[3];

					$rs->insertid = $meta[4];

					return $rs;

				}

			# Under high volume loads, we want only 1 thread/process to _write_file

			# so that we don't have 50 processes queueing to write the same data.

			# We use probabilistic timeout, ahead of time.

			#

			# -4 sec before timeout, give processes 1/32 chance of timing out

			# -2 sec before timeout, give processes 1/16 chance of timing out

			# -1 sec after timeout give processes 1/4 chance of timing out

			# +0 sec after timeout, give processes 100% chance of timing out

				if (sizeof($meta) > 1) {

					if($timeout >0){

						$tdiff = (integer)( $meta[1]+$timeout - time());

						if ($tdiff <= 2) {

							switch($tdiff) {

							case 4:

							case 3:

								if ((rand() & 31) == 0) {

									fclose($fp);

									$err = "Timeout 3";

									return $false;

								}

								break;

							case 2:

								if ((rand() & 15) == 0) {

									fclose($fp);

									$err = "Timeout 2";

									return $false;

								}

								break;

							case 1:

								if ((rand() & 3) == 0) {

									fclose($fp);

									$err = "Timeout 1";

									return $false;

								}

								break;

							default:

								fclose($fp);

								$err = "Timeout 0";

								return $false;

							} // switch

						} // if check flush cache

					}// (timeout>0)

					$ttl = $meta[1];

				}

				//================================================

				// new cache format - use serialize extensively...

				if ($meta[0] === '====1') {

					// slurp in the data

					$MAXSIZE = 128000;

					$text = fread($fp,$MAXSIZE);

					if (strlen($text)) {

						while ($txt = fread($fp,$MAXSIZE)) {

							$text .= $txt;

						}

					}

					fclose($fp);

					$rs = unserialize($text);

					if (is_object($rs)) $rs->timeCreated = $ttl;

					else {

						$err = "Unable to unserialize recordset";

						//echo htmlspecialchars($text),' !--END--!<p>';

					}

					return $rs;

				}

				$meta = false;

				$meta = fgetcsv($fp, 32000, ",");

				if (!$meta) {

					fclose($fp);

					$err = "Unexpected EOF 1";

					return $false;

				}

			}

			// Get Column definitions

			$flds = array();

			foreach($meta as $o) {

				$o2 = explode(':',$o);

				if (sizeof($o2)!=3) {

					$arr[] = $meta;

					$flds = false;

					break;

				}

				$fld = new ADOFieldObject();

				$fld->name = urldecode($o2[0]);

				$fld->type = $o2[1];

				$fld->max_length = $o2[2];

				$flds[] = $fld;

			}

		} else {

			fclose($fp);

			$err = "Recordset had unexpected EOF 2";

			return $false;

		}

		// slurp in the data

		$MAXSIZE = 128000;

		$text = '';

		while ($txt = fread($fp,$MAXSIZE)) {

			$text .= $txt;

		}

		fclose($fp);

		@$arr = unserialize($text);

		if (!is_array($arr)) {

			$err = "Recordset had unexpected EOF (in serialized recordset)";

			return $false;

		}

		$rs = new $rsclass();

		$rs->timeCreated = $ttl;

		$rs->InitArrayFields($arr,$flds);

		return $rs;

	}

	/**

	* Save a file $filename and its $contents (normally for caching) with file locking

	* Returns true if ok, false if fopen/fwrite error, 0 if rename error (eg. file is locked)

	*/

	function adodb_write_file($filename, $contents,$debug=false)

	{

	# http://www.php.net/bugs.php?id=9203 Bug that flock fails on Windows

	# So to simulate locking, we assume that rename is an atomic operation.

	# First we delete $filename, then we create a $tempfile write to it and

	# rename to the desired $filename. If the rename works, then we successfully

	# modified the file exclusively.

	# What a stupid need - having to simulate locking.

	# Risks:

	# 1. $tempfile name is not unique -- very very low

	# 2. unlink($filename) fails -- ok, rename will fail

	# 3. adodb reads stale file because unlink fails -- ok, $rs timeout occurs

	# 4. another process creates $filename between unlink() and rename() -- ok, rename() fails and  cache updated

		if (strncmp(PHP_OS,'WIN',3) === 0) {

			// skip the decimal place

			$mtime = substr(str_replace(' ','_',microtime()),2);

			// getmypid() actually returns 0 on Win98 - never mind!

			$tmpname = $filename.uniqid($mtime).getmypid();

			if (!($fd = @fopen($tmpname,'w'))) return false;

			if (fwrite($fd,$contents)) $ok = true;

			else $ok = false;

			fclose($fd);

			if ($ok) {

				@chmod($tmpname,0644);

				// the tricky moment

				@unlink($filename);

				if (!@rename($tmpname,$filename)) {

					@unlink($tmpname);

					$ok = 0;

				}

				if (!$ok) {

					if ($debug) ADOConnection::outp( " Rename $tmpname ".($ok? 'ok' : 'failed'));

				}

			}

			return $ok;

		}

		if (!($fd = @fopen($filename, 'a'))) return false;

		if (flock($fd, LOCK_EX) && ftruncate($fd, 0)) {

			if (fwrite( $fd, $contents )) $ok = true;

			else $ok = false;

			fclose($fd);

			@chmod($filename,0644);

		}else {

			fclose($fd);

			if ($debug)ADOConnection::outp( " Failed acquiring lock for $filename<br>\n");

			$ok = false;

		}

		return $ok;

	}