Major refactoring: add a cache table to accelerate the search of linked tags by inference (children and synonyms)

git-svn-id: https://semanticscuttle.svn.sourceforge.net/svnroot/semanticscuttle/trunk@204 b3834d28-1941-0410-a4f8-b48e95affb8f

1 files changed, 345 insertions, 0 deletions

diff --git a/services/tagcacheservice.php b/services/tagcacheservice.php
new file mode 100644
index 0000000..bb82864
--- /dev/null
+++ b/services/tagcacheservice.php
@@ -0,0 +1,345 @@
+<?php
+
+/*
+ * This class infers on relation between tags by storing all the including tags or synonymous tag.
+ * For example, if the user creates: tag1>tag2>tag3, the system can infer that tag is included into tag1.
+ * Instead of computing this relation several times, it is saved into this current table.
+ * For synonymy, this table stores also the group of synonymous tags.
+ * The table must be updated for each modification of the relations between tags.
+ */
+
+class TagCacheService {
+	var $db;
+	var $tablename;
+
+	function &getInstance(&$db) {
+		static $instance;
+		if (!isset($instance))
+		$instance =& new TagCacheService($db);
+		return $instance;
+	}
+
+	function TagCacheService(&$db) {
+		$this->db =& $db;
+		$this->tablename = $GLOBALS['tableprefix'] .'tagscache';
+	}
+
+	function getChildren($tag1, $uId) {
+		$tagservice =& ServiceFactory::getServiceInstance('TagService');
+		$tag1 = $tagservice->normalize($tag1);
+
+		if($tag1 == '') return false;
+
+		$query = "SELECT DISTINCT tag2 as 'tag'";
+		$query.= " FROM `". $this->getTableName() ."`";
+		$query.= " WHERE relationType = '>'";
+		$query.= " AND tag1 = '".$tag1."'";
+		$query.= " AND uId = '".$uId."'";
+
+		//die($query);
+		if (! ($dbresult =& $this->db->sql_query($query)) ){
+			message_die(GENERAL_ERROR, 'Could not get related tags', '', __LINE__, __FILE__, $query, $this->db);
+			return false;
+		}
+
+
+		$rowset = $this->db->sql_fetchrowset($dbresult);
+		$output = array();
+		foreach($rowset as $row) {
+			$output[] = $row['tag'];
+		}
+
+		return $output;
+	}
+
+	function addChild($tag1, $tag2, $uId) {
+		$tagservice =& ServiceFactory::getServiceInstance('TagService');
+		$tag1 = $tagservice->normalize($tag1);
+		$tag2 = $tagservice->normalize($tag2);
+
+		if($tag1 == $tag2 || strlen($tag1) == 0 || strlen($tag2) == 0
+		|| ($this->existsChild($tag1, $tag2, $uId))) {
+			return false;
+		}
+
+		$values = array('tag1' => $tag1, 'tag2' => $tag2, 'relationType'=> '>', 'uId'=> $uId);
+		$query = 'INSERT INTO '. $this->getTableName() .' '. $this->db->sql_build_array('INSERT', $values);
+		//die($query);
+		if (!($dbresult =& $this->db->sql_query($query))) {
+			$this->db->sql_transaction('rollback');
+			message_die(GENERAL_ERROR, 'Could not add tag cache inference', '', __LINE__, __FILE__, $query, $this->db);
+			return false;
+		}
+		$this->db->sql_transaction('commit');
+	}
+
+	function removeChild($tag1, $tag2, $uId) {
+		if(($tag1 != '' && $tag1 == $tag2) ||
+		($tag1 == '' && $tag2 == '' && $uId == '')) {
+			return false;
+		}
+
+		$query = 'DELETE FROM '. $this->getTableName();
+		$query.= ' WHERE 1=1';
+		$query.= strlen($tag1)>0 ? ' AND tag1 = "'. $tag1 .'"' : '';
+		$query.= strlen($tag2)>0 ? ' AND tag2 = "'. $tag2 .'"' : '';
+		$query.= ' AND relationType = ">"';
+		$query.= strlen($uId)>0 ? ' AND uId = "'. $uId .'"' : '';
+
+		if (!($dbresult =& $this->db->sql_query($query))) {
+			message_die(GENERAL_ERROR, 'Could not remove tag cache inference', '', __LINE__, __FILE__, $query, $this->db);
+			return false;
+		}
+	}
+	
+	function removeChildren($tag1, $uId) {
+		$this->removeChild($tag1, NULL, $uId);
+	}
+
+	function existsChild($tag1, $tag2, $uId) {
+		$tagservice =& ServiceFactory::getServiceInstance('TagService');
+		$tag1 = $tagservice->normalize($tag1);
+		$tag2 = $tagservice->normalize($tag2);
+
+		$query = "SELECT tag1, tag2, relationType, uId FROM `". $this->getTableName() ."`";
+		$query.= " WHERE tag1 = '" .$tag1 ."'";
+		$query.= " AND tag2 = '".$tag2."'";
+		$query.= " AND relationType = '>'";
+		$query.= " AND uId = '".$uId."'";
+
+		//echo($query."<br>\n");
+
+		return $this->db->sql_numrows($this->db->sql_query($query)) > 0;
+
+	}
+
+	/*
+	 * Synonyms of a same concept are a group. A group has one main synonym called key
+	 * and a list of synonyms called values.
+	 */
+	function addSynonym($tag1, $tag2, $uId) {
+
+		if($tag1 == $tag2 || strlen($tag1) == 0 || strlen($tag2) == 0
+		|| ($this->existsSynonym($tag1, $tag2, $uId))) {
+			return false;
+		}
+
+		$case1 = '0'; // not in DB
+		if($this->_isSynonymKey($tag1, $uId)) {
+			$case1 = 'key';
+		} elseif($this->_isSynonymValue($tag1, $uId)) {
+			$case1 = 'value';
+		}
+
+		$case2 = '0'; // not in DB
+		if($this->_isSynonymKey($tag2, $uId)) {
+			$case2 = 'key';
+		} elseif($this->_isSynonymValue($tag2, $uId)) {
+			$case2 = 'value';
+		}
+		$case = $case1.$case2;
+
+		// all the possible cases
+		switch ($case) {
+			case 'keykey':
+				$values = $this->_getSynonymValues($tag2, $uId);
+				$this->removeSynonymGroup($tag2, $uId);
+				foreach($values as $value) {
+					$this->addSynonym($tag1, $value['tag'], $uId);
+				}
+				$this->addSynonym($tag1, $tag2, $uId);
+				break;
+
+			case 'valuekey':
+				$key = $this->_getSynonymKey($tag1, $uId);
+				$this->addSynonym($key, $tag2, $uId);
+				break;
+
+			case 'keyvalue':
+				$this->addSynonym($tag2, $tag1, $uId);
+				break;
+			case 'valuevalue':
+				$key1 =  $this->_getSynonymKey($tag1, $uId);
+				$key2 =  $this->_getSynonymKey($tag2, $uId);
+				$this->addSynonym($key1, $key2, $uId);
+				break;
+			case '0value':
+				$key = $this->_getSynonymKey($tag2, $uId);
+				$this->addSynonym($key, $tag1, $uId);
+				break;
+			case 'value0':
+				$this->addSynonym($tag2, $tag1, $uId);
+				break;
+			case '0key':
+				$this->addSynonym($tag2, $tag1, $uId);
+				break;
+			default:
+				$values = array('tag1' => $tag1, 'tag2' => $tag2, 'relationType'=> '=', 'uId'=> $uId);
+				$query = 'INSERT INTO '. $this->getTableName() .' '. $this->db->sql_build_array('INSERT', $values);
+				//die($query);
+				if (!($dbresult =& $this->db->sql_query($query))) {
+					$this->db->sql_transaction('rollback');
+					message_die(GENERAL_ERROR, 'Could not add tag cache synonymy', '', __LINE__, __FILE__, $query, $this->db);
+					return false;
+				}
+				$this->db->sql_transaction('commit');
+				break;
+		}
+	}
+
+	function removeSynonymGroup($tag1, $uId) {		
+		$query = 'DELETE FROM '. $this->getTableName();
+		$query.= ' WHERE 1=1';
+		$query.= ' AND tag1 = "'. $tag1 .'"';
+		$query.= ' AND relationType = "="';
+		$query.= ' AND uId = "'. $uId .'"';
+
+		if (!($dbresult =& $this->db->sql_query($query))) {
+			message_die(GENERAL_ERROR, 'Could not remove tag cache inference', '', __LINE__, __FILE__, $query, $this->db);
+			return false;
+		}
+	}
+
+	function _isSynonymKey($tag1, $uId) {
+		$tagservice =& ServiceFactory::getServiceInstance('TagService');
+		$tag1 = $tagservice->normalize($tag1);
+
+		$query = "SELECT tag1 FROM `". $this->getTableName() ."`";
+		$query.= " WHERE tag1 = '" .$tag1 ."'";
+		$query.= " AND relationType = '='";
+		$query.= " AND uId = '".$uId."'";
+
+		return $this->db->sql_numrows($this->db->sql_query($query)) > 0;
+	}
+
+	function _isSynonymValue($tag2, $uId) {
+		$tagservice =& ServiceFactory::getServiceInstance('TagService');
+		$tag2 = $tagservice->normalize($tag2);
+
+		$query = "SELECT tag2 FROM `". $this->getTableName() ."`";
+		$query.= " WHERE tag2 = '" .$tag2 ."'";
+		$query.= " AND relationType = '='";
+		$query.= " AND uId = '".$uId."'";
+
+		return $this->db->sql_numrows($this->db->sql_query($query)) > 0;
+	}
+
+	function getSynonyms($tag1, $uId) {	
+		$values = array();	
+		if($this->_isSynonymKey($tag1, $uId)) {
+			$values = $this->_getSynonymValues($tag1, $uId);
+		} elseif($this->_isSynonymValue($tag1, $uId)) {
+			$key = $this->_getSynonymKey($tag1, $uId);
+			$values = $this->_getSynonymValues($key, $uId, $tag1);
+			$values[] = $key;			
+		}
+		return $values;
+	}
+
+	function _getSynonymKey($tag2, $uId) {
+		$tagservice =& ServiceFactory::getServiceInstance('TagService');
+		$tag2 = $tagservice->normalize($tag2);
+
+		if($this->_isSynonymKey($tag2)) return $tag2;
+		
+		if($tag2 == '') return false;
+
+		$query = "SELECT DISTINCT tag1 as 'tag'";
+		$query.= " FROM `". $this->getTableName() ."`";
+		$query.= " WHERE relationType = '='";
+		$query.= " AND tag2 = '".$tag2."'";
+		$query.= " AND uId = '".$uId."'";
+
+		//die($query);
+		if (! ($dbresult =& $this->db->sql_query($query)) ){
+			message_die(GENERAL_ERROR, 'Could not get related tags', '', __LINE__, __FILE__, $query, $this->db);
+			return false;
+		}
+
+		$row = $this->db->sql_fetchrow($dbresult);
+		return $row['tag'];
+	}
+
+	/*
+	 * Return values associated with a key.
+	 * $tagExcepted allows to hide a value.
+	 */
+	function _getSynonymValues($tag1, $uId, $tagExcepted = NULL) {
+		$tagservice =& ServiceFactory::getServiceInstance('TagService');
+		$tag1 = $tagservice->normalize($tag1);
+		$tagExcepted = $tagservice->normalize($tagExcepted);
+
+		if($tag1 == '') return false;
+
+		$query = "SELECT DISTINCT tag2 as 'tag'";
+		$query.= " FROM `". $this->getTableName() ."`";
+		$query.= " WHERE relationType = '='";
+		$query.= " AND tag1 = '".$tag1."'";
+		$query.= " AND uId = '".$uId."'";
+		$query.= $tagExcepted!=''?" AND tag2!='".$tagExcepted."'":"";
+
+		if (! ($dbresult =& $this->db->sql_query($query)) ){
+			message_die(GENERAL_ERROR, 'Could not get related tags', '', __LINE__, __FILE__, $query, $this->db);
+			return false;
+		}
+
+		$rowset = $this->db->sql_fetchrowset($dbresult);
+
+		$output = array();
+		foreach($rowset as $row) {
+			$output[] = $row['tag'];
+		}
+		return $output;
+	}
+
+	function existsSynonym($tag1, $tag2, $uId) {
+		if($this->_getSynonymKey($tag1, $uId) == $tag2 || $this->_getSynonymKey($tag2, $uId) == $tag1) {
+			return true;
+		} else {
+			return false;
+		}
+	}
+
+
+	function updateTag($tag1, $relationType, $otherTags, $uId) {
+		if($relationType == '=') {
+			if($this->getSynonyms($tag1, $uId)) {  // remove previous data avoiding unconstistency
+				$this->removeSynonymGroup($tag1, $uId);
+			}
+				
+			foreach($otherTags as $tag2) {
+				$this->addSynonym($tag1, $tag2, $uId);
+			}
+		} elseif($relationType == '>') {
+			if(count($this->getChildren($tag1, $uId))>0) { // remove previous data avoiding unconstistency
+				$this->removeChildren($tag1);
+			}
+			
+			foreach($otherTags as $tag2) {
+				$this->addChild($tag1, $tag2, $uId);
+			}
+		}		
+	}
+
+	function deleteByUser($uId) {
+		$query = 'DELETE FROM '. $this->getTableName() .' WHERE uId = '. intval($uId);
+
+		if (!($dbresult = & $this->db->sql_query($query))) {
+			message_die(GENERAL_ERROR, 'Could not delete user tags cache', '', __LINE__, __FILE__, $query, $this->db);
+			return false;
+		}
+
+		return true;
+
+	}
+
+	function deleteAll() {
+		$query = 'TRUNCATE TABLE `'. $this->getTableName() .'`';
+		$this->db->sql_query($query);
+	}
+
+	// Properties
+	function getTableName()       { return $this->tablename; }
+	function setTableName($value) { $this->tablename = $value; }
+}
+?>