web/Zend/Search/Lucene/MultiSearcher.php
changeset 0 4eba9c11703f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/Zend/Search/Lucene/MultiSearcher.php	Mon Dec 13 18:29:26 2010 +0100
@@ -0,0 +1,973 @@
+<?php
+/**
+ * Zend Framework
+ *
+ * LICENSE
+ *
+ * This source file is subject to the new BSD license that is bundled
+ * with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * http://framework.zend.com/license/new-bsd
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@zend.com so we can send you a copy immediately.
+ *
+ * @category   Zend
+ * @package    Zend_Search_Lucene
+ * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ * @version    $Id: MultiSearcher.php 22967 2010-09-18 18:53:58Z ramon $
+ */
+
+
+/** Zend_Search_Lucene_Interface */
+require_once 'Zend/Search/Lucene/Interface.php';
+
+/**
+ * Multisearcher allows to search through several independent indexes.
+ *
+ * @category   Zend
+ * @package    Zend_Search_Lucene
+ * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ */
+class Zend_Search_Lucene_Interface_MultiSearcher implements Zend_Search_Lucene_Interface
+{
+    /**
+     * List of indices for searching.
+     * Array of Zend_Search_Lucene_Interface objects
+     *
+     * @var array
+     */
+    protected $_indices;
+
+    /**
+     * Object constructor.
+     *
+     * @param array $indices   Arrays of indices for search
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function __construct($indices = array())
+    {
+        $this->_indices = $indices;
+
+        foreach ($this->_indices as $index) {
+            if (!$index instanceof Zend_Search_Lucene_Interface) {
+                require_once 'Zend/Search/Lucene/Exception.php';
+                throw new Zend_Search_Lucene_Exception('sub-index objects have to implement Zend_Search_Lucene_Interface.');
+            }
+        }
+    }
+
+    /**
+     * Add index for searching.
+     *
+     * @param Zend_Search_Lucene_Interface $index
+     */
+    public function addIndex(Zend_Search_Lucene_Interface $index)
+    {
+        $this->_indices[] = $index;
+    }
+
+
+    /**
+     * Get current generation number
+     *
+     * Returns generation number
+     * 0 means pre-2.1 index format
+     * -1 means there are no segments files.
+     *
+     * @param Zend_Search_Lucene_Storage_Directory $directory
+     * @return integer
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public static function getActualGeneration(Zend_Search_Lucene_Storage_Directory $directory)
+    {
+        require_once 'Zend/Search/Lucene/Exception.php';
+        throw new Zend_Search_Lucene_Exception("Generation number can't be retrieved for multi-searcher");
+    }
+
+    /**
+     * Get segments file name
+     *
+     * @param integer $generation
+     * @return string
+     */
+    public static function getSegmentFileName($generation)
+    {
+        return Zend_Search_Lucene::getSegmentFileName($generation);
+    }
+
+    /**
+     * Get index format version
+     *
+     * @return integer
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function getFormatVersion()
+    {
+        require_once 'Zend/Search/Lucene/Exception.php';
+        throw new Zend_Search_Lucene_Exception("Format version can't be retrieved for multi-searcher");
+    }
+
+    /**
+     * Set index format version.
+     * Index is converted to this format at the nearest upfdate time
+     *
+     * @param int $formatVersion
+     */
+    public function setFormatVersion($formatVersion)
+    {
+        foreach ($this->_indices as $index) {
+            $index->setFormatVersion($formatVersion);
+        }
+    }
+
+    /**
+     * Returns the Zend_Search_Lucene_Storage_Directory instance for this index.
+     *
+     * @return Zend_Search_Lucene_Storage_Directory
+     */
+    public function getDirectory()
+    {
+        require_once 'Zend/Search/Lucene/Exception.php';
+        throw new Zend_Search_Lucene_Exception("Index directory can't be retrieved for multi-searcher");
+    }
+
+    /**
+     * Returns the total number of documents in this index (including deleted documents).
+     *
+     * @return integer
+     */
+    public function count()
+    {
+        $count = 0;
+
+        foreach ($this->_indices as $index) {
+            $count += $index->count();
+        }
+
+        return $count;
+    }
+
+    /**
+     * Returns one greater than the largest possible document number.
+     * This may be used to, e.g., determine how big to allocate a structure which will have
+     * an element for every document number in an index.
+     *
+     * @return integer
+     */
+    public function maxDoc()
+    {
+        return $this->count();
+    }
+
+    /**
+     * Returns the total number of non-deleted documents in this index.
+     *
+     * @return integer
+     */
+    public function numDocs()
+    {
+        $docs = 0;
+
+        foreach ($this->_indices as $index) {
+            $docs += $index->numDocs();
+        }
+
+        return $docs;
+    }
+
+    /**
+     * Checks, that document is deleted
+     *
+     * @param integer $id
+     * @return boolean
+     * @throws Zend_Search_Lucene_Exception    Exception is thrown if $id is out of the range
+     */
+    public function isDeleted($id)
+    {
+        foreach ($this->_indices as $index) {
+            $indexCount = $index->count();
+
+            if ($indexCount > $id) {
+                return $index->isDeleted($id);
+            }
+
+            $id -= $indexCount;
+        }
+
+        require_once 'Zend/Search/Lucene/Exception.php';
+        throw new Zend_Search_Lucene_Exception('Document id is out of the range.');
+    }
+
+    /**
+     * Set default search field.
+     *
+     * Null means, that search is performed through all fields by default
+     *
+     * Default value is null
+     *
+     * @param string $fieldName
+     */
+    public static function setDefaultSearchField($fieldName)
+    {
+        foreach ($this->_indices as $index) {
+            $index->setDefaultSearchField($fieldName);
+        }
+    }
+
+
+    /**
+     * Get default search field.
+     *
+     * Null means, that search is performed through all fields by default
+     *
+     * @return string
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public static function getDefaultSearchField()
+    {
+        if (count($this->_indices) == 0) {
+            require_once 'Zend/Search/Lucene/Exception.php';
+            throw new Zend_Search_Lucene_Exception('Indices list is empty');
+        }
+
+        $defaultSearchField = reset($this->_indices)->getDefaultSearchField();
+
+        foreach ($this->_indices as $index) {
+            if ($index->getDefaultSearchField() !== $defaultSearchField) {
+                require_once 'Zend/Search/Lucene/Exception.php';
+                throw new Zend_Search_Lucene_Exception('Indices have different default search field.');
+            }
+        }
+
+        return $defaultSearchField;
+    }
+
+    /**
+     * Set result set limit.
+     *
+     * 0 (default) means no limit
+     *
+     * @param integer $limit
+     */
+    public static function setResultSetLimit($limit)
+    {
+        foreach ($this->_indices as $index) {
+            $index->setResultSetLimit($limit);
+        }
+    }
+
+    /**
+     * Set result set limit.
+     *
+     * 0 means no limit
+     *
+     * @return integer
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public static function getResultSetLimit()
+    {
+        if (count($this->_indices) == 0) {
+            require_once 'Zend/Search/Lucene/Exception.php';
+            throw new Zend_Search_Lucene_Exception('Indices list is empty');
+        }
+
+        $defaultResultSetLimit = reset($this->_indices)->getResultSetLimit();
+
+        foreach ($this->_indices as $index) {
+            if ($index->getResultSetLimit() !== $defaultResultSetLimit) {
+                require_once 'Zend/Search/Lucene/Exception.php';
+                throw new Zend_Search_Lucene_Exception('Indices have different default search field.');
+            }
+        }
+
+        return $defaultResultSetLimit;
+    }
+
+    /**
+     * Retrieve index maxBufferedDocs option
+     *
+     * maxBufferedDocs is a minimal number of documents required before
+     * the buffered in-memory documents are written into a new Segment
+     *
+     * Default value is 10
+     *
+     * @return integer
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function getMaxBufferedDocs()
+    {
+        if (count($this->_indices) == 0) {
+            require_once 'Zend/Search/Lucene/Exception.php';
+            throw new Zend_Search_Lucene_Exception('Indices list is empty');
+        }
+
+        $maxBufferedDocs = reset($this->_indices)->getMaxBufferedDocs();
+
+        foreach ($this->_indices as $index) {
+            if ($index->getMaxBufferedDocs() !== $maxBufferedDocs) {
+                require_once 'Zend/Search/Lucene/Exception.php';
+                throw new Zend_Search_Lucene_Exception('Indices have different default search field.');
+            }
+        }
+
+        return $maxBufferedDocs;
+    }
+
+    /**
+     * Set index maxBufferedDocs option
+     *
+     * maxBufferedDocs is a minimal number of documents required before
+     * the buffered in-memory documents are written into a new Segment
+     *
+     * Default value is 10
+     *
+     * @param integer $maxBufferedDocs
+     */
+    public function setMaxBufferedDocs($maxBufferedDocs)
+    {
+        foreach ($this->_indices as $index) {
+            $index->setMaxBufferedDocs($maxBufferedDocs);
+        }
+    }
+
+    /**
+     * Retrieve index maxMergeDocs option
+     *
+     * maxMergeDocs is a largest number of documents ever merged by addDocument().
+     * Small values (e.g., less than 10,000) are best for interactive indexing,
+     * as this limits the length of pauses while indexing to a few seconds.
+     * Larger values are best for batched indexing and speedier searches.
+     *
+     * Default value is PHP_INT_MAX
+     *
+     * @return integer
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function getMaxMergeDocs()
+    {
+        if (count($this->_indices) == 0) {
+            require_once 'Zend/Search/Lucene/Exception.php';
+            throw new Zend_Search_Lucene_Exception('Indices list is empty');
+        }
+
+        $maxMergeDocs = reset($this->_indices)->getMaxMergeDocs();
+
+        foreach ($this->_indices as $index) {
+            if ($index->getMaxMergeDocs() !== $maxMergeDocs) {
+                require_once 'Zend/Search/Lucene/Exception.php';
+                throw new Zend_Search_Lucene_Exception('Indices have different default search field.');
+            }
+        }
+
+        return $maxMergeDocs;
+    }
+
+    /**
+     * Set index maxMergeDocs option
+     *
+     * maxMergeDocs is a largest number of documents ever merged by addDocument().
+     * Small values (e.g., less than 10,000) are best for interactive indexing,
+     * as this limits the length of pauses while indexing to a few seconds.
+     * Larger values are best for batched indexing and speedier searches.
+     *
+     * Default value is PHP_INT_MAX
+     *
+     * @param integer $maxMergeDocs
+     */
+    public function setMaxMergeDocs($maxMergeDocs)
+    {
+        foreach ($this->_indices as $index) {
+            $index->setMaxMergeDocs($maxMergeDocs);
+        }
+    }
+
+    /**
+     * Retrieve index mergeFactor option
+     *
+     * mergeFactor determines how often segment indices are merged by addDocument().
+     * With smaller values, less RAM is used while indexing,
+     * and searches on unoptimized indices are faster,
+     * but indexing speed is slower.
+     * With larger values, more RAM is used during indexing,
+     * and while searches on unoptimized indices are slower,
+     * indexing is faster.
+     * Thus larger values (> 10) are best for batch index creation,
+     * and smaller values (< 10) for indices that are interactively maintained.
+     *
+     * Default value is 10
+     *
+     * @return integer
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function getMergeFactor()
+    {
+        if (count($this->_indices) == 0) {
+            require_once 'Zend/Search/Lucene/Exception.php';
+            throw new Zend_Search_Lucene_Exception('Indices list is empty');
+        }
+
+        $mergeFactor = reset($this->_indices)->getMergeFactor();
+
+        foreach ($this->_indices as $index) {
+            if ($index->getMergeFactor() !== $mergeFactor) {
+                require_once 'Zend/Search/Lucene/Exception.php';
+                throw new Zend_Search_Lucene_Exception('Indices have different default search field.');
+            }
+        }
+
+        return $mergeFactor;
+    }
+
+    /**
+     * Set index mergeFactor option
+     *
+     * mergeFactor determines how often segment indices are merged by addDocument().
+     * With smaller values, less RAM is used while indexing,
+     * and searches on unoptimized indices are faster,
+     * but indexing speed is slower.
+     * With larger values, more RAM is used during indexing,
+     * and while searches on unoptimized indices are slower,
+     * indexing is faster.
+     * Thus larger values (> 10) are best for batch index creation,
+     * and smaller values (< 10) for indices that are interactively maintained.
+     *
+     * Default value is 10
+     *
+     * @param integer $maxMergeDocs
+     */
+    public function setMergeFactor($mergeFactor)
+    {
+        foreach ($this->_indices as $index) {
+            $index->setMaxMergeDocs($mergeFactor);
+        }
+    }
+
+    /**
+     * Performs a query against the index and returns an array
+     * of Zend_Search_Lucene_Search_QueryHit objects.
+     * Input is a string or Zend_Search_Lucene_Search_Query.
+     *
+     * @param mixed $query
+     * @return array Zend_Search_Lucene_Search_QueryHit
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function find($query)
+    {
+        if (count($this->_indices) == 0) {
+            return array();
+        }
+
+        $hitsList = array();
+
+        $indexShift = 0;
+        foreach ($this->_indices as $index) {
+            $hits = $index->find($query);
+
+            if ($indexShift != 0) {
+                foreach ($hits as $hit) {
+                    $hit->id += $indexShift;
+                }
+            }
+
+            $indexShift += $index->count();
+            $hitsList[] = $hits;
+        }
+
+        /** @todo Implement advanced sorting */
+
+        return call_user_func_array('array_merge', $hitsList);
+    }
+
+    /**
+     * Returns a list of all unique field names that exist in this index.
+     *
+     * @param boolean $indexed
+     * @return array
+     */
+    public function getFieldNames($indexed = false)
+    {
+        $fieldNamesList = array();
+
+        foreach ($this->_indices as $index) {
+            $fieldNamesList[] = $index->getFieldNames($indexed);
+        }
+
+        return array_unique(call_user_func_array('array_merge', $fieldNamesList));
+    }
+
+    /**
+     * Returns a Zend_Search_Lucene_Document object for the document
+     * number $id in this index.
+     *
+     * @param integer|Zend_Search_Lucene_Search_QueryHit $id
+     * @return Zend_Search_Lucene_Document
+     * @throws Zend_Search_Lucene_Exception    Exception is thrown if $id is out of the range
+     */
+    public function getDocument($id)
+    {
+        if ($id instanceof Zend_Search_Lucene_Search_QueryHit) {
+            /* @var $id Zend_Search_Lucene_Search_QueryHit */
+            $id = $id->id;
+        }
+
+        foreach ($this->_indices as $index) {
+            $indexCount = $index->count();
+
+            if ($indexCount > $id) {
+                return $index->getDocument($id);
+            }
+
+            $id -= $indexCount;
+        }
+
+        require_once 'Zend/Search/Lucene/Exception.php';
+        throw new Zend_Search_Lucene_Exception('Document id is out of the range.');
+    }
+
+    /**
+     * Returns true if index contain documents with specified term.
+     *
+     * Is used for query optimization.
+     *
+     * @param Zend_Search_Lucene_Index_Term $term
+     * @return boolean
+     */
+    public function hasTerm(Zend_Search_Lucene_Index_Term $term)
+    {
+        foreach ($this->_indices as $index) {
+            if ($index->hasTerm($term)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Returns IDs of all the documents containing term.
+     *
+     * @param Zend_Search_Lucene_Index_Term $term
+     * @param Zend_Search_Lucene_Index_DocsFilter|null $docsFilter
+     * @return array
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function termDocs(Zend_Search_Lucene_Index_Term $term, $docsFilter = null)
+    {
+        if ($docsFilter != null) {
+            require_once 'Zend/Search/Lucene/Exception.php';
+            throw new Zend_Search_Lucene_Exception('Document filters could not used with multi-searcher');
+        }
+
+        $docsList = array();
+
+        $indexShift = 0;
+        foreach ($this->_indices as $index) {
+            $docs = $index->termDocs($term);
+
+            if ($indexShift != 0) {
+                foreach ($docs as $id => $docId) {
+                    $docs[$id] += $indexShift;
+                }
+            }
+
+            $indexShift += $index->count();
+            $docsList[] = $docs;
+        }
+
+        return call_user_func_array('array_merge', $docsList);
+    }
+
+    /**
+     * Returns documents filter for all documents containing term.
+     *
+     * It performs the same operation as termDocs, but return result as
+     * Zend_Search_Lucene_Index_DocsFilter object
+     *
+     * @param Zend_Search_Lucene_Index_Term $term
+     * @param Zend_Search_Lucene_Index_DocsFilter|null $docsFilter
+     * @return Zend_Search_Lucene_Index_DocsFilter
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function termDocsFilter(Zend_Search_Lucene_Index_Term $term, $docsFilter = null)
+    {
+        require_once 'Zend/Search/Lucene/Exception.php';
+        throw new Zend_Search_Lucene_Exception('Document filters could not used with multi-searcher');
+    }
+
+    /**
+     * Returns an array of all term freqs.
+     * Return array structure: array( docId => freq, ...)
+     *
+     * @param Zend_Search_Lucene_Index_Term $term
+     * @param Zend_Search_Lucene_Index_DocsFilter|null $docsFilter
+     * @return integer
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function termFreqs(Zend_Search_Lucene_Index_Term $term, $docsFilter = null)
+    {
+        if ($docsFilter != null) {
+            require_once 'Zend/Search/Lucene/Exception.php';
+            throw new Zend_Search_Lucene_Exception('Document filters could not used with multi-searcher');
+        }
+
+        $freqsList = array();
+
+        $indexShift = 0;
+        foreach ($this->_indices as $index) {
+            $freqs = $index->termFreqs($term);
+
+            if ($indexShift != 0) {
+                $freqsShifted = array();
+
+                foreach ($freqs as $docId => $freq) {
+                    $freqsShifted[$docId + $indexShift] = $freq;
+                }
+                $freqs = $freqsShifted;
+            }
+
+            $indexShift += $index->count();
+            $freqsList[] = $freqs;
+        }
+
+        return call_user_func_array('array_merge', $freqsList);
+    }
+
+    /**
+     * Returns an array of all term positions in the documents.
+     * Return array structure: array( docId => array( pos1, pos2, ...), ...)
+     *
+     * @param Zend_Search_Lucene_Index_Term $term
+     * @param Zend_Search_Lucene_Index_DocsFilter|null $docsFilter
+     * @return array
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function termPositions(Zend_Search_Lucene_Index_Term $term, $docsFilter = null)
+    {
+        if ($docsFilter != null) {
+            require_once 'Zend/Search/Lucene/Exception.php';
+            throw new Zend_Search_Lucene_Exception('Document filters could not used with multi-searcher');
+        }
+
+        $termPositionsList = array();
+
+        $indexShift = 0;
+        foreach ($this->_indices as $index) {
+            $termPositions = $index->termPositions($term);
+
+            if ($indexShift != 0) {
+                $termPositionsShifted = array();
+
+                foreach ($termPositions as $docId => $positions) {
+                    $termPositions[$docId + $indexShift] = $positions;
+                }
+                $termPositions = $termPositionsShifted;
+            }
+
+            $indexShift += $index->count();
+            $termPositionsList[] = $termPositions;
+        }
+
+        return call_user_func_array('array_merge', $termPositions);
+    }
+
+    /**
+     * Returns the number of documents in this index containing the $term.
+     *
+     * @param Zend_Search_Lucene_Index_Term $term
+     * @return integer
+     */
+    public function docFreq(Zend_Search_Lucene_Index_Term $term)
+    {
+        $docFreq = 0;
+
+        foreach ($this->_indices as $index) {
+            $docFreq += $index->docFreq($term);
+        }
+
+        return $docFreq;
+    }
+
+    /**
+     * Retrive similarity used by index reader
+     *
+     * @return Zend_Search_Lucene_Search_Similarity
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function getSimilarity()
+    {
+        if (count($this->_indices) == 0) {
+            require_once 'Zend/Search/Lucene/Exception.php';
+            throw new Zend_Search_Lucene_Exception('Indices list is empty');
+        }
+
+        $similarity = reset($this->_indices)->getSimilarity();
+
+        foreach ($this->_indices as $index) {
+            if ($index->getSimilarity() !== $similarity) {
+                require_once 'Zend/Search/Lucene/Exception.php';
+                throw new Zend_Search_Lucene_Exception('Indices have different similarity.');
+            }
+        }
+
+        return $similarity;
+    }
+
+    /**
+     * Returns a normalization factor for "field, document" pair.
+     *
+     * @param integer $id
+     * @param string $fieldName
+     * @return float
+     */
+    public function norm($id, $fieldName)
+    {
+        foreach ($this->_indices as $index) {
+            $indexCount = $index->count();
+
+            if ($indexCount > $id) {
+                return $index->norm($id, $fieldName);
+            }
+
+            $id -= $indexCount;
+        }
+
+        return null;
+    }
+
+    /**
+     * Returns true if any documents have been deleted from this index.
+     *
+     * @return boolean
+     */
+    public function hasDeletions()
+    {
+        foreach ($this->_indices as $index) {
+            if ($index->hasDeletions()) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Deletes a document from the index.
+     * $id is an internal document id
+     *
+     * @param integer|Zend_Search_Lucene_Search_QueryHit $id
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function delete($id)
+    {
+        foreach ($this->_indices as $index) {
+            $indexCount = $index->count();
+
+            if ($indexCount > $id) {
+                $index->delete($id);
+                return;
+            }
+
+            $id -= $indexCount;
+        }
+
+        require_once 'Zend/Search/Lucene/Exception.php';
+        throw new Zend_Search_Lucene_Exception('Document id is out of the range.');
+    }
+
+
+    /**
+     * Callback used to choose target index for new documents
+     *
+     * Function/method signature:
+     *    Zend_Search_Lucene_Interface  callbackFunction(Zend_Search_Lucene_Document $document, array $indices);
+     *
+     * null means "default documents distributing algorithm"
+     *
+     * @var callback
+     */
+    protected $_documentDistributorCallBack = null;
+
+    /**
+     * Set callback for choosing target index.
+     *
+     * @param callback $callback
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function setDocumentDistributorCallback($callback)
+    {
+        if ($callback !== null  &&  !is_callable($callback)) {
+            require_once 'Zend/Search/Lucene/Exception.php';
+            throw new Zend_Search_Lucene_Exception('$callback parameter must be a valid callback.');
+        }
+
+        $this->_documentDistributorCallBack = $callback;
+    }
+
+    /**
+     * Get callback for choosing target index.
+     *
+     * @return callback
+     */
+    public function getDocumentDistributorCallback()
+    {
+        return $this->_documentDistributorCallBack;
+    }
+
+    /**
+     * Adds a document to this index.
+     *
+     * @param Zend_Search_Lucene_Document $document
+     * @throws Zend_Search_Lucene_Exception
+     */
+    public function addDocument(Zend_Search_Lucene_Document $document)
+    {
+        if ($this->_documentDistributorCallBack !== null) {
+            $index = call_user_func($this->_documentDistributorCallBack, $document, $this->_indices);
+        } else {
+            $index = $this->_indices[array_rand($this->_indices)];
+        }
+
+        $index->addDocument($document);
+    }
+
+    /**
+     * Commit changes resulting from delete() or undeleteAll() operations.
+     */
+    public function commit()
+    {
+        foreach ($this->_indices as $index) {
+            $index->commit();
+        }
+    }
+
+    /**
+     * Optimize index.
+     *
+     * Merges all segments into one
+     */
+    public function optimize()
+    {
+        foreach ($this->_indices as $index) {
+            $index->optimise();
+        }
+    }
+
+    /**
+     * Returns an array of all terms in this index.
+     *
+     * @return array
+     */
+    public function terms()
+    {
+        $termsList = array();
+
+        foreach ($this->_indices as $index) {
+            $termsList[] = $index->terms();
+        }
+
+        return array_unique(call_user_func_array('array_merge', $termsList));
+    }
+
+
+    /**
+     * Terms stream priority queue object
+     *
+     * @var Zend_Search_Lucene_TermStreamsPriorityQueue
+     */
+    private $_termsStream = null;
+
+    /**
+     * Reset terms stream.
+     */
+    public function resetTermsStream()
+    {
+        if ($this->_termsStream === null) {
+            /** Zend_Search_Lucene_TermStreamsPriorityQueue */
+            require_once 'Zend/Search/Lucene/TermStreamsPriorityQueue.php';
+
+            $this->_termsStream = new Zend_Search_Lucene_TermStreamsPriorityQueue($this->_indices);
+        } else {
+            $this->_termsStream->resetTermsStream();
+        }
+    }
+
+    /**
+     * Skip terms stream up to specified term preffix.
+     *
+     * Prefix contains fully specified field info and portion of searched term
+     *
+     * @param Zend_Search_Lucene_Index_Term $prefix
+     */
+    public function skipTo(Zend_Search_Lucene_Index_Term $prefix)
+    {
+        $this->_termsStream->skipTo($prefix);
+    }
+
+    /**
+     * Scans terms dictionary and returns next term
+     *
+     * @return Zend_Search_Lucene_Index_Term|null
+     */
+    public function nextTerm()
+    {
+        return $this->_termsStream->nextTerm();
+    }
+
+    /**
+     * Returns term in current position
+     *
+     * @return Zend_Search_Lucene_Index_Term|null
+     */
+    public function currentTerm()
+    {
+        return $this->_termsStream->currentTerm();
+    }
+
+    /**
+     * Close terms stream
+     *
+     * Should be used for resources clean up if stream is not read up to the end
+     */
+    public function closeTermsStream()
+    {
+        $this->_termsStream->closeTermsStream();
+        $this->_termsStream = null;
+    }
+
+
+    /**
+     * Undeletes all documents currently marked as deleted in this index.
+     */
+    public function undeleteAll()
+    {
+        foreach ($this->_indices as $index) {
+            $index->undeleteAll();
+        }
+    }
+
+
+    /**
+     * Add reference to the index object
+     *
+     * @internal
+     */
+    public function addReference()
+    {
+        // Do nothing, since it's never referenced by indices
+    }
+
+    /**
+     * Remove reference from the index object
+     *
+     * When reference count becomes zero, index is closed and resources are cleaned up
+     *
+     * @internal
+     */
+    public function removeReference()
+    {
+        // Do nothing, since it's never referenced by indices
+    }
+}