questlab/www/analytics/core/Segment.php
2014-05-14 18:30:25 +02:00

454 lines
16 KiB
PHP

<?php
/**
* Piwik - Open source web analytics
*
* @link http://piwik.org
* @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
*
*/
namespace Piwik;
use Exception;
use Piwik\Plugins\API\API;
/**
* Limits the set of visits Piwik uses when aggregating analytics data.
*
* A segment is a condition used to filter visits. They can, for example,
* select visits that have a specific browser or come from a specific
* country, or both.
*
* Individual segment dimensions (such as `browserCode` and `countryCode`)
* are defined by plugins. Read about the {@hook API.getSegmentDimensionMetadata}
* event to learn more.
*
* Plugins that aggregate data stored in Piwik can support segments by
* using this class when generating aggregation SQL queries.
*
* ### Examples
*
* **Basic usage**
*
* $idSites = array(1,2,3);
* $segmentStr = "browserCode==ff;countryCode==CA";
* $segment = new Segment($segmentStr, $idSites);
*
* $query = $segment->getSelectQuery(
* $select = "table.col1, table2.col2",
* $from = array("table", "table2"),
* $where = "table.col3 = ?",
* $bind = array(5),
* $orderBy = "table.col1 DESC",
* $groupBy = "table2.col2"
* );
*
* Db::fetchAll($query['sql'], $query['bind']);
*
* **Creating a _null_ segment**
*
* $idSites = array(1,2,3);
* $segment = new Segment('', $idSites);
* // $segment->getSelectQuery will return a query that selects all visits
*
* @api
*/
class Segment
{
/**
* @var SegmentExpression
*/
protected $segment = null;
/**
* Truncate the Segments to 8k
*/
const SEGMENT_TRUNCATE_LIMIT = 8192;
/**
* Constructor.
*
* @param string $segmentCondition The segment condition, eg, `'browserCode=ff;countryCode=CA'`.
* @param array $idSites The list of sites the segment will be used with. Some segments are
* dependent on the site, such as goal segments.
*/
public function __construct($segmentCondition, $idSites)
{
$segmentCondition = trim($segmentCondition);
if (!SettingsPiwik::isSegmentationEnabled()
&& !empty($segmentCondition)
) {
throw new Exception("The Super User has disabled the Segmentation feature.");
}
// First try with url decoded value. If that fails, try with raw value.
// If that also fails, it will throw the exception
try {
$this->initializeSegment(urldecode($segmentCondition), $idSites);
} catch (Exception $e) {
$this->initializeSegment($segmentCondition, $idSites);
}
}
/**
* @param $string
* @param $idSites
* @throws Exception
*/
protected function initializeSegment($string, $idSites)
{
// As a preventive measure, we restrict the filter size to a safe limit
$string = substr($string, 0, self::SEGMENT_TRUNCATE_LIMIT);
$this->string = $string;
$this->idSites = $idSites;
$segment = new SegmentExpression($string);
$this->segment = $segment;
// parse segments
$expressions = $segment->parseSubExpressions();
// convert segments name to sql segment
// check that user is allowed to view this segment
// and apply a filter to the value to match if necessary (to map DB fields format)
$cleanedExpressions = array();
foreach ($expressions as $expression) {
$operand = $expression[SegmentExpression::INDEX_OPERAND];
$cleanedExpression = $this->getCleanedExpression($operand);
$expression[SegmentExpression::INDEX_OPERAND] = $cleanedExpression;
$cleanedExpressions[] = $expression;
}
$segment->setSubExpressionsAfterCleanup($cleanedExpressions);
}
/**
* Returns `true` if the segment is empty, `false` if otherwise.
*/
public function isEmpty()
{
return empty($this->string);
}
protected $availableSegments = array();
protected function getCleanedExpression($expression)
{
if (empty($this->availableSegments)) {
$this->availableSegments = API::getInstance()->getSegmentsMetadata($this->idSites, $_hideImplementationData = false);
}
$name = $expression[0];
$matchType = $expression[1];
$value = $expression[2];
$sqlName = '';
foreach ($this->availableSegments as $segment) {
if ($segment['segment'] != $name) {
continue;
}
$sqlName = $segment['sqlSegment'];
// check permission
if (isset($segment['permission'])
&& $segment['permission'] != 1
) {
throw new Exception("You do not have enough permission to access the segment " . $name);
}
if($matchType != SegmentExpression::MATCH_IS_NOT_NULL_NOR_EMPTY
&& $matchType != SegmentExpression::MATCH_IS_NULL_OR_EMPTY) {
if(isset($segment['sqlFilterValue'])) {
$value = call_user_func($segment['sqlFilterValue'], $value);
}
// apply presentation filter
if (isset($segment['sqlFilter'])) {
$value = call_user_func($segment['sqlFilter'], $value, $segment['sqlSegment'], $matchType, $name);
// sqlFilter-callbacks might return arrays for more complex cases
// e.g. see TableLogAction::getIdActionFromSegment()
if (is_array($value) && isset($value['SQL'])) {
// Special case: returned value is a sub sql expression!
$matchType = SegmentExpression::MATCH_ACTIONS_CONTAINS;
}
}
}
break;
}
if (empty($sqlName)) {
throw new Exception("Segment '$name' is not a supported segment.");
}
return array($sqlName, $matchType, $value);
}
/**
* Returns the segment condition.
*
* @return string
*/
public function getString()
{
return $this->string;
}
/**
* Returns a hash of the segment condition, or the empty string if the segment
* condition is empty.
*
* @return string
*/
public function getHash()
{
if (empty($this->string)) {
return '';
}
// normalize the string as browsers may send slightly different payloads for the same archive
$normalizedSegmentString = urldecode($this->string);
return md5($normalizedSegmentString);
}
/**
* Extend an SQL query that aggregates data over one of the 'log_' tables with segment expressions.
*
* @param string $select The select clause. Should NOT include the **SELECT** just the columns, eg,
* `'t1.col1 as col1, t2.col2 as col2'`.
* @param array $from Array of table names (without prefix), eg, `array('log_visit', 'log_conversion')`.
* @param false|string $where (optional) Where clause, eg, `'t1.col1 = ? AND t2.col2 = ?'`.
* @param array|string $bind (optional) Bind parameters, eg, `array($col1Value, $col2Value)`.
* @param false|string $orderBy (optional) Order by clause, eg, `"t1.col1 ASC"`.
* @param false|string $groupBy (optional) Group by clause, eg, `"t2.col2"`.
* @return string The entire select query.
*/
public function getSelectQuery($select, $from, $where = false, $bind = array(), $orderBy = false, $groupBy = false)
{
if (!is_array($from)) {
$from = array($from);
}
if (!$this->isEmpty()) {
$this->segment->parseSubExpressionsIntoSqlExpressions($from);
$joins = $this->generateJoins($from);
$from = $joins['sql'];
$joinWithSubSelect = $joins['joinWithSubSelect'];
$segmentSql = $this->segment->getSql();
$segmentWhere = $segmentSql['where'];
if (!empty($segmentWhere)) {
if (!empty($where)) {
$where = "( $where )
AND
($segmentWhere)";
} else {
$where = $segmentWhere;
}
}
$bind = array_merge($bind, $segmentSql['bind']);
} else {
$joins = $this->generateJoins($from);
$from = $joins['sql'];
$joinWithSubSelect = $joins['joinWithSubSelect'];
}
if ($joinWithSubSelect) {
$sql = $this->buildWrappedSelectQuery($select, $from, $where, $orderBy, $groupBy);
} else {
$sql = $this->buildSelectQuery($select, $from, $where, $orderBy, $groupBy);
}
return array(
'sql' => $sql,
'bind' => $bind
);
}
/**
* Generate the join sql based on the needed tables
* @param array $tables tables to join
* @throws Exception if tables can't be joined
* @return array
*/
private function generateJoins($tables)
{
$knownTables = array("log_visit", "log_link_visit_action", "log_conversion", "log_conversion_item");
$visitsAvailable = $actionsAvailable = $conversionsAvailable = $conversionItemAvailable = false;
$joinWithSubSelect = false;
$sql = '';
// make sure the tables are joined in the right order
// base table first, then action before conversion
// this way, conversions can be joined on idlink_va
$actionIndex = array_search("log_link_visit_action", $tables);
$conversionIndex = array_search("log_conversion", $tables);
if ($actionIndex > 0 && $conversionIndex > 0 && $actionIndex > $conversionIndex) {
$tables[$actionIndex] = "log_conversion";
$tables[$conversionIndex] = "log_link_visit_action";
}
// same as above: action before visit
$actionIndex = array_search("log_link_visit_action", $tables);
$visitIndex = array_search("log_visit", $tables);
if ($actionIndex > 0 && $visitIndex > 0 && $actionIndex > $visitIndex) {
$tables[$actionIndex] = "log_visit";
$tables[$visitIndex] = "log_link_visit_action";
}
foreach ($tables as $i => $table) {
if (is_array($table)) {
// join condition provided
$alias = isset($table['tableAlias']) ? $table['tableAlias'] : $table['table'];
$sql .= "
LEFT JOIN " . Common::prefixTable($table['table']) . " AS " . $alias
. " ON " . $table['joinOn'];
continue;
}
if (!in_array($table, $knownTables)) {
throw new Exception("Table '$table' can't be used for segmentation");
}
$tableSql = Common::prefixTable($table) . " AS $table";
if ($i == 0) {
// first table
$sql .= $tableSql;
} else {
if ($actionsAvailable && $table == "log_conversion") {
// have actions, need conversions => join on idlink_va
$join = "log_conversion.idlink_va = log_link_visit_action.idlink_va "
. "AND log_conversion.idsite = log_link_visit_action.idsite";
} else if ($actionsAvailable && $table == "log_visit") {
// have actions, need visits => join on idvisit
$join = "log_visit.idvisit = log_link_visit_action.idvisit";
} else if ($visitsAvailable && $table == "log_link_visit_action") {
// have visits, need actions => we have to use a more complex join
// we don't hande this here, we just return joinWithSubSelect=true in this case
$joinWithSubSelect = true;
$join = "log_link_visit_action.idvisit = log_visit.idvisit";
} else if ($conversionsAvailable && $table == "log_link_visit_action") {
// have conversions, need actions => join on idlink_va
$join = "log_conversion.idlink_va = log_link_visit_action.idlink_va";
} else if (($visitsAvailable && $table == "log_conversion")
|| ($conversionsAvailable && $table == "log_visit")
) {
// have visits, need conversion (or vice versa) => join on idvisit
// notice that joining conversions on visits has lower priority than joining it on actions
$join = "log_conversion.idvisit = log_visit.idvisit";
// if conversions are joined on visits, we need a complex join
if ($table == "log_conversion") {
$joinWithSubSelect = true;
}
} elseif ($conversionItemAvailable && $table === 'log_visit') {
$join = "log_conversion_item.idvisit = log_visit.idvisit";
} elseif ($conversionItemAvailable && $table === 'log_link_visit_action') {
$join = "log_conversion_item.idvisit = log_link_visit_action.idvisit";
} elseif ($conversionItemAvailable && $table === 'log_conversion') {
$join = "log_conversion_item.idvisit = log_conversion.idvisit";
} else {
throw new Exception("Table '$table' can't be joined for segmentation");
}
// the join sql the default way
$sql .= "
LEFT JOIN $tableSql ON $join";
}
// remember which tables are available
$visitsAvailable = ($visitsAvailable || $table == "log_visit");
$actionsAvailable = ($actionsAvailable || $table == "log_link_visit_action");
$conversionsAvailable = ($conversionsAvailable || $table == "log_conversion");
$conversionItemAvailable = ($conversionItemAvailable || $table == "log_conversion_item");
}
$return = array(
'sql' => $sql,
'joinWithSubSelect' => $joinWithSubSelect
);
return $return;
}
/**
* Build select query the normal way
* @param string $select fieldlist to be selected
* @param string $from tablelist to select from
* @param string $where where clause
* @param string $orderBy order by clause
* @param string $groupBy group by clause
* @return string
*/
private function buildSelectQuery($select, $from, $where, $orderBy, $groupBy)
{
$sql = "
SELECT
$select
FROM
$from";
if ($where) {
$sql .= "
WHERE
$where";
}
if ($groupBy) {
$sql .= "
GROUP BY
$groupBy";
}
if ($orderBy) {
$sql .= "
ORDER BY
$orderBy";
}
return $sql;
}
/**
* Build a select query where actions have to be joined on visits (or conversions)
* In this case, the query gets wrapped in another query so that grouping by visit is possible
* @param string $select
* @param string $from
* @param string $where
* @param string $orderBy
* @param string $groupBy
* @throws Exception
* @return string
*/
private function buildWrappedSelectQuery($select, $from, $where, $orderBy, $groupBy)
{
$matchTables = "(log_visit|log_conversion_item|log_conversion|log_action)";
preg_match_all("/". $matchTables ."\.[a-z0-9_\*]+/", $select, $matches);
$neededFields = array_unique($matches[0]);
if (count($neededFields) == 0) {
throw new Exception("No needed fields found in select expression. "
. "Please use a table prefix.");
}
$select = preg_replace('/'.$matchTables.'\./', 'log_inner.', $select);
$orderBy = preg_replace('/'.$matchTables.'\./', 'log_inner.', $orderBy);
$groupBy = preg_replace('/'.$matchTables.'\./', 'log_inner.', $groupBy);
$from = "(
SELECT
" . implode(",
", $neededFields) . "
FROM
$from
WHERE
$where
GROUP BY log_visit.idvisit
) AS log_inner";
$where = false;
$query = $this->buildSelectQuery($select, $from, $where, $orderBy, $groupBy);
return $query;
}
}