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<?php
/**
* Shlib - programming library
*
* @author Yannick Gaultier
* @copyright (c) Yannick Gaultier 2013
* @package shlib
* @license http://www.gnu.org/copyleft/gpl.html GNU/GPL
* @version 0.2.9.370
* @date 2014-06-11
*/
// Security check to ensure this file is being included by a parent file.
defined('_JEXEC') or die;
class ShlDbClass extends ShlSystem_Abstractdecorator
{
const CACHE_STATS_DATASET_NAME = 'shl_database';
// instance unique name
public $instanceName = '';
// query cache option
public $queryCacheEnabled = true;
public $queryCacheEnabledForJoomla = false;
public $queryCacheTableExclusionList = array('#__sh404sef_urls', '#__extensions', '#__schemas', '#__session', '#__update_categories',
'#__update_sites', '#__update_sites_extensions', '#__updates');
// a unique id needed when using the query cache
public $queryCacheUid = '';
// flag to help decide if this is a Joomla db
// request or one that goes through our db helper
private $_isShLibHelper = false;
/**
* Provides an object with cache usage stats
* for the current page load only
*/
public function shlGetCacheStats()
{
return ShlCache_Manager::getCacheStats(self::CACHE_STATS_DATASET_NAME);
}
/**
*
* Prepare a query, quoting or name quoting some
* of its constituents
* ?? will be replaced with name quoted data from the $nameQuoted parameter
* ? will be replaced with quoted data from the $quoted parameter
*
* Example:
* $query = 'select ?? from ?? where ?? <> ?'
* with
* $nameQuoted = array( 'id', '#__table', 'counter')
* $quoted = array( 'test')
*
* will return
*
* select `id` from `#__table` where `counter` <> 'test'
*
*
* @param string $query
* @param array $nameQuoted
* @param array $quoted
* @param string $namePlaceHolder
* @param string $dataPlaceHolder
*/
public function shlQuoteQuery($query, $nameQuoted = array(), $quoted = array(), $namePlaceHolder = '??', $dataPlaceHolder = '?')
{
$newQuery = '';
// name quoting
if (!empty($nameQuoted))
{
// find placeholders
$sqlBits = explode($namePlaceHolder, $query);
$i = 0;
// replace each place holder by the matching value
foreach ($nameQuoted as $data)
{
$newQuery .= $sqlBits[$i];
$newQuery .= $this->quoteName($data);
$i += 1;
}
if (isset($sqlBits[$i]))
{
$newQuery .= $sqlBits[$i];
}
}
if (strpos($newQuery, $namePlaceHolder) !== false)
{
throw new ShlDbException(__METHOD__ . ': ' . 'Invalid db query sent to queryQuote helper: ' . $query . '. Maybe missing some data.');
}
// name quoting
if (!empty($quoted))
{
// find placeholders
$sqlBits = explode($dataPlaceHolder, $newQuery);
$newQuery = '';
$i = 0;
// replace each place holder by the matching value
foreach ($quoted as $data)
{
$newQuery .= $sqlBits[$i];
$newQuery .= $this->_shlPrepareData($data);
$i += 1;
}
if (isset($sqlBits[$i]))
{
$newQuery .= $sqlBits[$i];
}
}
return $newQuery;
}
/**
* Prepare and set a query against the db object
*
* @param String $table The table name
* @param Array $aData An array of field to be inserted in the db ('columnName' => 'columnValue')
* @param String $mWhere Conditions. Taken as a litteral where clause ( WHERE `amount` > 100 ).
* @param Array $mWhere ( ie 'columnName' => 'columnValue') : a where clause is created like so : WHERE `columnName` = 'columnValue'. columnValue is escaped before being used
* @param Array $aWhereData Used only if $aWhere is a string. In such case, '?' place holders will be replaced by this array values, escaped
*/
public function shlSetInsertUpdateQuery($table, $aData, $mWhere = '', $aWhereData = array())
{
if ($this->shlIsRecord($table, $mWhere, $aWhereData))
{
// update it
$this->shlSetUpdateQuery($table, $aData, $mWhere, $aWhereData);
}
else
{
// or insert it
$this->shlSetInsertQuery($table, $aData);
}
return $this;
}
/**
* Prepare and set a SELECT query against the db
*
* @param String $table The table name
* @param Array $aColList array of strings of columns to be fetched
* @param String $mWhere Conditions. Taken as a litteral where clause ( WHERE `amount` > 100 ).
* @param Array $mWhere ( ie 'columnName' => 'columnValue') : a where clause is created like so : WHERE `columnName` = 'columnValue'. columnValue is escaped before being used
* @param Array $aWhereData Used only if $aWhere is a string. In such case, '?' place holders will be replaced by this array values, escaped
* @param Array $orderBy, a list of columns to order the results
* @param Integer $offset, first line of result set to select
* @param Integer $lines, max number of lines to select
*/
public function shlSetSelectQuery($table, $aColList = array('*'), $mWhere = '', $aWhereData = array(), $orderBy = array(), $offset = 0,
$lines = 0)
{
// sanitize
$aColList = empty($aColList) ? array('*') : $aColList;
$aColList = is_string($aColList) ? array($aColList) : $aColList;
// which columns to fetch ?
$quotedColList = array();
foreach ($aColList as $columnName)
{
$quotedColList[] = $columnName == '*' ? '*' : $this->quoteName($columnName);
}
$columns = implode(', ', $quotedColList);
// where to look for
$where = $this->_shlBuildWhereClause($mWhere, $aWhereData);
// order by clause
$orderByClause = $this->_shlBuildOrderByClause($orderBy);
// lines limit clause
$limitClause = $this->_shlBuildLimitClause($offset, $lines);
// set up the query
$this->setQuery('SELECT ' . $columns . ' FROM ' . $table . $where . $orderByClause . $limitClause . ';');
return $this;
} // end of setSelectQuery
/**
* Prepare and set a select/count query against the db
*
* @param String $table The table name
* @param String $column an optional column to be counter
* @param String $mWhere Conditions. Taken as a litteral where clause ( WHERE `amount` > 100 ).
* @param Array $mWhere ( ie 'columnName' => 'columnValue') : a where clause is created like so : WHERE `columnName` = 'columnValue'. columnValue is escaped before being used
* @param Array $aWhereData Used only if $aWhere is a string. In such case, '?' place holders will be replaced by this array values, escaped
*/
public function shlSetCountQuery($table, $column = '*', $mWhere = '', $aWhereData = array())
{
// sanitize
$column = empty($column) || $column == '*' ? '*' : $this->quoteName($column);
// where to look for
$where = $this->_shlBuildWhereClause($mWhere, $aWhereData);
// set up the query
$this->setQuery('SELECT count(' . $column . ') FROM ' . $table . $where . ';');
return $this;
} // end of setSelectQuery
/**
* Prepare and set an UPDATE query against the db
*
* @param String $table The table name
* @param Array $aData array of values pairs ( ie 'columnName' => 'columnValue')
* @param String $mWhere Conditions. Taken as a litteral where clause ( WHERE `amount` > 100 ).
* @param Array $mWhere ( ie 'columnName' => 'columnValue') : a where clause is created like so : WHERE `columnName` = 'columnValue'. columnValue is escaped before being used
* @param Array $aWhereData Used only if $aWhere is a string. In such case, '?' place holders will be replaced by this array values, escaped
*/
public function shlSetUpdateQuery($table, $aData, $mWhere = '', $aWhereData = array())
{
// which columns to set ?
$set = '';
if (!empty($aData))
{
foreach ($aData as $columnName => $columnValue)
{
$set .= ', ' . $this->quoteName($columnName) . '=' . $this->_shlPrepareData($columnValue);
}
// remove leading ', '
$set = substr($set, 2);
}
// check result
if (empty($set))
{
return false;
}
// where to look for
$where = $this->_shlBuildWhereClause($mWhere, $aWhereData);
// set up the query
$this->setQuery('UPDATE ' . $this->quoteName($table) . ' SET ' . $set . $where . ';');
return $this;
}
/**
* Prepare and set an INSERT query against the db
*
* @param String $table The table name
* @param Array $aData array of values pairs ( ie 'columnName' => 'columnValue')
*/
public function shlSetInsertQuery($table, $aData)
{
// which columns to set ?
$columns = '';
$values = '';
if (!empty($aData))
{
foreach ($aData as $columnName => $columnValue)
{
$columns .= ', ' . $this->quoteName($columnName);
$values .= ', ' . $this->_shlPrepareData($columnValue);
}
// remove leading ', '
$columns = substr($columns, 2);
$values = substr($values, 2);
}
// set up the query
$this->setQuery('INSERT INTO ' . $this->quoteName($table) . ' (' . $columns . ') VALUES (' . $values . ');');
return $this;
}
/**
* Prepare and set a DELETE query against the db
*
* @param String $table The table name
* @param String $mWhere Conditions. Taken as a litteral where clause ( WHERE `amount` > 100 ).
* @param Array $mWhere ( ie 'columnName' => 'columnValue') : a where clause is created like so : WHERE `columnName` = 'columnValue'. columnValue is escaped before being used
* @param Array $aWhereData Used only if $aWhere is a string. In such case, '?' place holders will be replaced by this array values, escaped
*/
public function shlSetDeleteQuery($table, $mWhere = '', $aWhereData = array())
{
// where to look for
$where = $this->_shlBuildWhereClause($mWhere, $aWhereData);
// set up the query
$this->setQuery('DELETE FROM ' . $this->quoteName($table) . $where . ';');
return $this;
}
/**
* Returns true if a record exists matching 'where' condition
*
* @param String $table, the table to look into
* @param String $mWhere Conditions. Taken as a litteral where clause ( WHERE `amount` > 100 ).
* @param Array $mWhere ( ie 'columnName' => 'columnValue') : a where clause is created like so : WHERE `columnName` = 'columnValue'. columnValue is escaped before being used
* @param Array $aWhereData Used only if $aWhere is a string. In such case, '?' place holders will be replaced by this array values, escaped
*/
public function shlIsRecord($table, $mWhere = '', $aWhereData = array())
{
// where to look for
$where = $this->_shlBuildWhereClause($mWhere, $aWhereData);
if (empty($where))
{
return false;
}
// set up the query and load result
$this->setQuery('SELECT count(*) FROM ' . $this->quoteName($table) . $where . ';');
$result = $this->shlLoadResult();
return !empty($result);
}
/**
* Returns true if a record exists with a given Id
*
* @param String $table, the table to look into
* @param Integer $id, the id to look for
* @param String $idName, default to 'id', the columns to look into, if not 'id'
*/
public function shlIsRecordById($table, $id, $idName = 'id')
{
$id = (int) $id;
if (empty($id))
{
return false;
}
// get db and look up record
$this->shlSetSelectQuery($table, array($idName), array($id));
$result = $this->shlLoadResult();
return !empty($result);
}
/**
* Wrapper around J! method, which
* throws exceptions
*/
public function shlLoadResult()
{
$this->_isShLibHelper = true;
$result = $this->loadResult();
$error = $this->getErrorNum();
if (!empty($error))
{
throw new ShlDbException($this->getErrorMsg(), $error);
}
$this->_isShLibHelper = false;
return $result;
}
/**
* Wrapper around J! method, which
* throws exceptions
* @deprecated Use shlLoadColumn() instead
*/
public function shlLoadResultArray($numinarray = 0)
{
ShlSystem_Log::debug('shlib', 'Using deprecated ShlDbClass::shlLoadResultArray() method. Use ShlDbClass::shlLoadColumn() instead');
return $this->shlLoadColumn($numinarray);
}
/**
* Wrapper around J! method, which
* throws exceptions
*/
public function shlLoadColumn($offset = 0)
{
$this->_isShLibHelper = true;
$array = $this->loadColumn($offset);
$error = $this->getErrorNum();
if (!empty($error))
{
throw new ShlDbException($this->getErrorMsg(), $error);
}
$this->_isShLibHelper = false;
return $array;
}
/**
* Wrapper around J! method, which
* throws exceptions
*/
public function shlLoadAssoc()
{
$this->_isShLibHelper = true;
$result = $this->loadAssoc();
$error = $this->getErrorNum();
if (!empty($error))
{
throw new ShlDbException($this->getErrorMsg(), $error);
}
$this->_isShLibHelper = false;
return $result;
}
/**
* Wrapper around J! method, which
* throws exceptions
*/
public function shlLoadAssocList($key = '')
{
$this->_isShLibHelper = true;
$result = $this->loadAssocList($key);
$error = $this->getErrorNum();
if (!empty($error))
{
throw new ShlDbException($this->getErrorMsg(), $error);
}
$this->_isShLibHelper = false;
return $result;
}
/**
* Wrapper around J! method, which
* throws exceptions
*/
public function shlLoadObject($className = 'stdClass')
{
$this->_isShLibHelper = true;
$object = $this->loadObject($className);
$error = $this->getErrorNum();
if (!empty($error))
{
throw new ShlDbException($this->getErrorMsg(), $error);
}
$this->_isShLibHelper = false;
return $object;
}
/**
* Wrapper around J! method, which
* throws exceptions
*/
public function shlLoadObjectList($key = '', $className = 'stdClass')
{
$this->_isShLibHelper = true;
$objectList = $this->loadObjectList($key, $className);
$error = $this->getErrorNum();
if (!empty($error))
{
throw new ShlDbException($this->getErrorMsg(), $error);
}
$this->_isShLibHelper = false;
return $objectList;
}
/**
* Wrapper around J! method, which
* throws exceptions
*/
public function shlQuery()
{
return $this->shlExecute();
}
/**
* Wrapper around J! method, which
* throws exceptions
*/
public function shlExecute()
{
$this->_isShLibHelper = true;
$status = $this->execute();
$error = empty($status) ? $this->getErrorNum() : '';
if (!empty($error))
{
throw new ShlDbException($this->getErrorMsg(), $error);
}
$this->_isShLibHelper = false;
return $this;
}
/**
* Base J! object overrides. These 3 methods are shortcuts
* implemented by Joomla! through a __call() magic method
* As we override Joomla! own __call() method
* we must re-implement those ourselves for B/C compat
*
*/
public function q()
{
$args = func_get_args();
return $this->quote($args[0], isset($args[1]) ? $args[1] : true);
}
public function nq()
{
$args = func_get_args();
return $this->quoteName($args[0]);
}
public function qn()
{
$args = func_get_args();
return $this->quoteName($args[0]);
}
/**
* Base J! object overrides, to allow query caching
*
*/
/**
* Method to get the first row of the result set from the database query as an associative array
* of ['field_name' => 'row_value'].
*
* @return mixed The return value or null if the query failed.
*
* @since 11.1
* @throws JDatabaseException
*/
public function loadAssoc()
{
// check cache
$cachedValue = $this->_shlQueryCacheRead('loadAssoc');
if ($cachedValue !== false)
{
return $cachedValue;
}
// call decorated object
$read = $this->_decorated->loadAssoc();
// and store in cache
$this->_shlQueryCacheStore($read, 'loadAssoc');
return $read;
}
/**
* Method to get an array of the result set rows from the database query where each row is an associative array
* of ['field_name' => 'row_value']. The array of rows can optionally be keyed by a field name, but defaults to
* a sequential numeric array.
*
* NOTE: Chosing to key the result array by a non-unique field name can result in unwanted
* behavior and should be avoided.
*
* @param string $key The name of a field on which to key the result array.
* @param string $column An optional column name. Instead of the whole row, only this column value will be in
* the result array.
*
* @return mixed The return value or null if the query failed.
*
* @since 11.1
* @throws JDatabaseException
*/
public function loadAssocList($key = null, $column = null)
{
// check cache
$cachedValue = $this->_shlQueryCacheRead('loadAssocList');
if ($cachedValue !== false)
{
return $cachedValue;
}
// call decorated object
$read = $this->_decorated->loadAssocList($key, $column);
// and store in cache
$this->_shlQueryCacheStore($read, 'loadAssocList');
return $read;
}
/**
* Method to get an array of values from the <var>$offset</var> field in each row of the result set from
* the database query.
*
* @param integer $offset The row offset to use to build the result array.
*
* @return mixed The return value or null if the query failed.
*
* @since 11.1
* @throws JDatabaseException
*/
public function loadColumn($offset = 0)
{
// check cache
$cachedValue = $this->_shlQueryCacheRead('loadColumn');
if ($cachedValue !== false)
{
return $cachedValue;
}
// call decorated object
$read = $this->_decorated->loadColumn($offset);
// and store in cache
$this->_shlQueryCacheStore($read, 'loadColumn');
return $read;
}
/**
* Method to get the first row of the result set from the database query as an object.
*
* @param string $class The class name to use for the returned row object.
*
* @return mixed The return value or null if the query failed.
*
* @since 11.1
* @throws JDatabaseException
*/
public function loadObject($class = 'stdClass')
{
// check cache
$cachedValue = $this->_shlQueryCacheRead('loadObject');
if ($cachedValue !== false)
{
return $cachedValue;
}
// call decorated object
$read = $this->_decorated->loadObject($class);
// and store in cache
$this->_shlQueryCacheStore($read, 'loadObject');
return $read;
}
/**
* Method to get an array of the result set rows from the database query where each row is an object. The array
* of objects can optionally be keyed by a field name, but defaults to a sequential numeric array.
*
* NOTE: Choosing to key the result array by a non-unique field name can result in unwanted
* behavior and should be avoided.
*
* @param string $key The name of a field on which to key the result array.
* @param string $class The class name to use for the returned row objects.
*
* @return mixed The return value or null if the query failed.
*
* @since 11.1
* @throws JDatabaseException
*/
public function loadObjectList($key = '', $class = 'stdClass')
{
// check cache
$cachedValue = $this->_shlQueryCacheRead('loadObjectList');
if ($cachedValue !== false)
{
return $cachedValue;
}
// call decorated object
$read = $this->_decorated->loadObjectList($key, $class);
// and store in cache
$this->_shlQueryCacheStore($read, 'loadObjectList');
return $read;
}
/**
* Method to get the first field of the first row of the result set from the database query.
*
* @return mixed The return value or null if the query failed.
*
* @since 11.1
* @throws JDatabaseException
*/
public function loadResult()
{
// check cache
$cachedValue = $this->_shlQueryCacheRead('loadResult');
if ($cachedValue !== false)
{
return $cachedValue;
}
// call decorated object
$read = $this->_decorated->loadResult();
// and store in cache
$this->_shlQueryCacheStore($read, 'loadResult');
return $read;
}
/**
* Method to get the first row of the result set from the database query as an array. Columns are indexed
* numerically so the first column in the result set would be accessible via <var>$row[0]</var>, etc.
*
* @return mixed The return value or null if the query failed.
*
* @since 11.1
* @throws JDatabaseException
*/
public function loadRow()
{
// check cache
$cachedValue = $this->_shlQueryCacheRead('loadRow');
if ($cachedValue !== false)
{
return $cachedValue;
}
// call decorated object
$read = $this->_decorated->loadRow();
// and store in cache
$this->_shlQueryCacheStore($read, 'loadRow');
return $read;
}
/**
* Method to get an array of the result set rows from the database query where each row is an array. The array
* of objects can optionally be keyed by a field offset, but defaults to a sequential numeric array.
*
* NOTE: Choosing to key the result array by a non-unique field can result in unwanted
* behavior and should be avoided.
*
* @param string $key The name of a field on which to key the result array.
*
* @return mixed The return value or null if the query failed.
*
* @since 11.1
* @throws JDatabaseException
*/
public function loadRowList($key = null)
{
// check cache
$cachedValue = $this->_shlQueryCacheRead('loadRowList');
if ($cachedValue !== false)
{
return $cachedValue;
}
// call decorated object
$read = $this->_decorated->loadRowList($key);
// and store in cache
$this->_shlQueryCacheStore($read, 'loadRowList');
return $read;
}
/**
* Workarounds: we have to implement those 2 proxies to cover for
* Joomla!'s implementation that uses reference for one of the
* method params. This is not compatible with our decorator
* technique, which uses __call() and call_user_func()
* that cannot handle references.
*/
public function updateObject($table, &$object, $key, $nulls = false)
{
return $this->_decorated->updateObject($table, $object, $key, $nulls);
}
public function insertObject($table, &$object, $key = null)
{
return $this->_decorated->insertObject($table, $object, $key);
}
/**
* Prepare data to be inserted in an sql statement
*
* @param mixed $data
*/
protected function _shlPrepareData($data)
{
// from Ron Baldwin <ron.baldwin#sourceprose.com>
// Only quote string types
$type = gettype($data);
if ($type == 'string')
{
$ret = $this->quote($data);
}
else if ($type == 'double')
{
$ret = str_replace(',', '.', $data); // locales fix so 1.1 does not get converted to 1,1
}
else if ($type == 'boolean')
{
$ret = $data ? '1' : '0';
}
else if ($type == 'object')
{
if (method_exists($data, '__toString'))
{
$ret = $this->quote($data->__toString());
}
else
{
$ret = $this->quote((string) $data);
}
}
else if ($data === null)
{
$ret = 'NULL';
}
else
{
$ret = $data;
}
return $ret;
}
/**
* Build a where clause
*
* @param String $mWhere Conditions. Taken as a litteral where clause ( WHERE `amount` > 100 ).
* @param Array $mWhere ( ie 'columnName' => 'columnValue') : a where clause is created like so : WHERE `columnName` = 'columnValue'. columnValue is escaped before being used
* @param Array $aWhereData Used only if $aWhere is a string. In such case, '?' place holders will be replaced by this array values, escaped
*/
protected function _shlBuildWhereClause($mWhere = '', $aWhereData = array())
{
// where clause
if (is_string($mWhere))
{
// litteral clause, find ? place holders
if (!is_array($aWhereData))
$aWhereData = array($aWhereData);
$holderCount = substr_count($mWhere, '?');
if ($holderCount = 0 || $holderCount != count($aWhereData))
{
// there is no ? place holders, or their number does not match the data array passed
throw new ShlDbException(
__METHOD__ . ': ' . 'Internal error: trying to build invalid db query where clause [ ' . serialize($mWhere) . ' ] [ '
. serialize($aWhereData) . ' ]', 500);
}
else
{
// we have ? placeholders and their number equals that of data passed
$where = '';
// find placeholders
$sqlBits = explode('?', $mWhere);
$i = 0;
// replace each place holder by the matching value
foreach ($aWhereData as $data)
{
$where .= $sqlBits[$i];
$where .= $this->_shlPrepareData($data);
$i += 1;
}
if (isset($sqlBits[$i]))
{
$where .= $sqlBits[$i];
}
}
}
elseif (is_array($mWhere))
{
// an array of columns/values, we must turn into a where clause
$where = '';
foreach ($mWhere as $columns => $value)
{
$where .= ' AND ' . $this->quoteName($columns) . '=' . $this->_shlPrepareData($value);
}
// remove initial AND
$where = substr($where, 5);
}
else
{
$where = '';
}
return empty($where) ? '' : ' WHERE ' . $where;
}
/**
* Builds an ORDER BY sql statement
*
* $orderBy = 'title';
* $orderBy = array( 'extension' => '', 'title' => 'desc');
* $orderBy = array( 'extension', 'title');
*
* @param String $orderBy name of unique column to sort with, direction is always ASC
* @param Array $orderBy a list of column names to order by, direction is always asc
* @param Array $orderBy a list of key => values, where key is a column name, and value is either '', 'asc' or 'desc'
*/
protected function _shlBuildOrderByClause($orderBy)
{
if (empty($orderBy))
{
return '';
}
$clause = '';
// 1: $orderBy is a string
if (is_string($orderBy))
{
$clause = $this->quoteName($orderBy);
}
else if (is_array($orderBy))
{
foreach ($orderBy as $key => $value)
{
if (is_int($key))
{
// 2 : $orderBy is an array of strings
// use directly, always with no direction
$clause .= ', ' . $this->quoteName((string) $value);
}
else
{
// 3 : $orderBy is an array of column names with direction
$clause .= ', ' . $this->quoteName($key) . (empty($value) ? '' : $this->escape($value));
}
}
$clause = empty($clause) ? '' : substr($clause, 2);
}
// put everything together
$clause = empty($clause) ? '' : ' ORDER BY ' . $clause;
return $clause;
}
/**
* Builds a LIMIT sql statement
*
* @param Integer $offset, the line in result set to start with
* @param Integer $lines, the max number of lines in result set to return
*/
protected function _shlBuildLimitClause($offset, $lines)
{
if (empty($offset) && empty($lines))
{
return '';
}
$clause = ' LIMIT ';
if (!empty($offset))
{
$clause .= $this->_shlPrepareData($offset);
}
if (!empty($lines))
{
$clause .= (empty($offset) ? '' : ', ') . $this->_shlPrepareData($lines);
}
return $clause;
}
/**
* Store the result of a db query into the query cache
* (if such feature is present and enabled)
*
* @param mixed $value the value to be stored
* @param string $prefix a prefix string to identify db operation, on top of sql query
* @return boolean $stored true if successfully stored, false if not
* @throws ShlDbException in case of cache internal error. Cache will be disabled if this happens (for current db instance)
*
*/
protected function _shlQueryCacheStore($value, $prefix)
{
$stored = false;
if ($this->_shlCanCache())
{
try
{
// cache id is made of db instance prepended with full sql query
$stored = ShlCache_Manager::store($this->instanceName . $prefix . $this->getQuery(), self::CACHE_STATS_DATASET_NAME, $value);
}
catch (Exception $e)
{
// there was an error: log that and disable cache for this instance
$this->queryCacheEnabled = false;
ShlSystem_Log::error('shlib',
__METHOD__ . ': error storing data in query cache for instance %s, disabling cache for this instance (%s)', $this->instanceName,
$e->getMessage());
}
}
return $stored;
}
/**
* Search the query cache for the previously stored
* result of a given database sql query
* (if such cache feature is present and enabled)
* The desired query must have been already prepared and set
* into the ShlDbClass database object passed to this method
*
* @param string $prefix a prefix string to identify db operation, on top of sql query
* @return mixed $read false if nothing found, whatever was found in the cache otherwise
* @throws ShlDbException in case of cache internal error. Cache will be disabled if this happens (for current db instance)
*/
protected function _shlQueryCacheRead($prefix)
{
$read = false;
if ($this->_shlCanCache())
{
try
{
// cache id is made of db instance prepended with full sql query
$read = ShlCache_Manager::read($this->instanceName . $prefix . $this->getQuery(), self::CACHE_STATS_DATASET_NAME);
}
catch (Exception $e)
{
// there was an error: log that and disable cache for this instance
$this->queryCacheEnabled = false;
ShlSystem_Log::error('shlib',
__METHOD__ . ': error reading data in query cache for instance %s, disabling cache for this instance (%s)', $this->instanceName,
$e->getMessage());
}
}
return is_null($read) ? false : $read;
}
/**
* Decide whether current opeation can read from/stored to
* query cache. Query cache must be enabled globally, but also,
* if this is a query coming directly from Joomla (ie not
* through our db helper class), query caching from Joomla should
* be enabled as well.
* Second condition is tha the query does not operate
* on one of the exluded db tables
*/
protected function _shlCanCache()
{
// 1st: enabled/disabled conditions
if (!$this->queryCacheEnabled)
{
return false;
}
if (!$this->_isShLibHelper && !$this->queryCacheEnabledForJoomla)
{
return false;
}
$app = JFactory::getApplication();
if (!$app->isSite())
{
return false;
}
// 2nd: does the query have excluded tables?
$sql = $this->getQuery();
foreach ($this->queryCacheTableExclusionList as $tableName)
{
if (strpos($sql, $tableName) !== false)
{
return false;
}
}
// various conditions
// if Joomla! content/categories queries with publish_up/down fields
// don't cache, as these fields are changing every seconds
if (strpos($sql, 'publish_up <=') !== false || strpos($sql, '>= a.publish_up') !== false || strpos($sql, 'publish_down >=') !== false
|| strpos($sql, '<= a.publish_down') !== false)
{
return false;
}
return true;
}
}