1 <?php

     2 /**

     3  * Zend Framework

     4  *

     5  * LICENSE

     6  *

     7  * This source file is subject to the new BSD license that is bundled

     8  * with this package in the file LICENSE.txt.

     9  * It is also available through the world-wide-web at this URL:

    10  * http://framework.zend.com/license/new-bsd

    11  * If you did not receive a copy of the license and are unable to

    12  * obtain it through the world-wide-web, please send an email

    13  * to license@zend.com so we can send you a copy immediately.

    14  *

    15  * @category   Zend

    16  * @package    Zend_Search_Lucene

    17  * @subpackage Index

    18  * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

    19  * @license    http://framework.zend.com/license/new-bsd     New BSD License

    20  * @version    $Id: TermStreamsPriorityQueue.php 22987 2010-09-21 10:39:53Z alexander $

    21  */

    22 

    23 /** Zend_Search_Lucene_Index_TermsStream_Interface */

    24 require_once 'Zend/Search/Lucene/Index/TermsStream/Interface.php';

    25 

    26 

    27 /**

    28  * @category   Zend

    29  * @package    Zend_Search_Lucene

    30  * @subpackage Index

    31  * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

    32  * @license    http://framework.zend.com/license/new-bsd     New BSD License

    33  */

    34 class Zend_Search_Lucene_TermStreamsPriorityQueue implements Zend_Search_Lucene_Index_TermsStream_Interface

    35 {

    36     /**

    37      * Array of term streams (Zend_Search_Lucene_Index_TermsStream_Interface objects)

    38      *

    39      * @var array

    40      */

    41     protected $_termStreams;

    42 

    43     /**

    44      * Terms stream queue

    45      *

    46      * @var Zend_Search_Lucene_Index_TermsPriorityQueue

    47      */

    48     protected $_termsStreamQueue = null;

    49 

    50     /**

    51      * Last Term in a terms stream

    52      *

    53      * @var Zend_Search_Lucene_Index_Term

    54      */

    55     protected $_lastTerm = null;

    56 

    57 

    58     /**

    59      * Object constructor

    60      *

    61      * @param array $termStreams  array of term streams (Zend_Search_Lucene_Index_TermsStream_Interface objects)

    62      */

    63     public function __construct(array $termStreams)

    64     {

    65         $this->_termStreams = $termStreams;

    66 

    67         $this->resetTermsStream();

    68     }

    69 

    70     /**

    71      * Reset terms stream.

    72      */

    73     public function resetTermsStream()

    74     {

    75         /** Zend_Search_Lucene_Index_TermsPriorityQueue */

    76         require_once 'Zend/Search/Lucene/Index/TermsPriorityQueue.php';

    77 

    78         $this->_termsStreamQueue = new Zend_Search_Lucene_Index_TermsPriorityQueue();

    79 

    80         foreach ($this->_termStreams as $termStream) {

    81             $termStream->resetTermsStream();

    82 

    83             // Skip "empty" containers

    84             if ($termStream->currentTerm() !== null) {

    85                 $this->_termsStreamQueue->put($termStream);

    86             }

    87         }

    88 

    89         $this->nextTerm();

    90     }

    91 

    92     /**

    93      * Skip terms stream up to the specified term preffix.

    94      *

    95      * Prefix contains fully specified field info and portion of searched term

    96      *

    97      * @param Zend_Search_Lucene_Index_Term $prefix

    98      */

    99     public function skipTo(Zend_Search_Lucene_Index_Term $prefix)

   100     {

   101         $this->_termsStreamQueue = new Zend_Search_Lucene_Index_TermsPriorityQueue();

   102 

   103         foreach ($this->_termStreams as $termStream) {

   104             $termStream->skipTo($prefix);

   105 

   106             if ($termStream->currentTerm() !== null) {

   107                 $this->_termsStreamQueue->put($termStream);

   108             }

   109         }

   110 

   111         return $this->nextTerm();

   112     }

   113 

   114     /**

   115      * Scans term streams and returns next term

   116      *

   117      * @return Zend_Search_Lucene_Index_Term|null

   118      */

   119     public function nextTerm()

   120     {

   121         while (($termStream = $this->_termsStreamQueue->pop()) !== null) {

   122             if ($this->_termsStreamQueue->top() === null ||

   123                 $this->_termsStreamQueue->top()->currentTerm()->key() !=

   124                             $termStream->currentTerm()->key()) {

   125                 // We got new term

   126                 $this->_lastTerm = $termStream->currentTerm();

   127 

   128                 if ($termStream->nextTerm() !== null) {

   129                     // Put segment back into the priority queue

   130                     $this->_termsStreamQueue->put($termStream);

   131                 }

   132 

   133                 return $this->_lastTerm;

   134             }

   135 

   136             if ($termStream->nextTerm() !== null) {

   137                 // Put segment back into the priority queue

   138                 $this->_termsStreamQueue->put($termStream);

   139             }

   140         }

   141 

   142         // End of stream

   143         $this->_lastTerm = null;

   144 

   145         return null;

   146     }

   147 

   148     /**

   149      * Returns term in current position

   150      *

   151      * @return Zend_Search_Lucene_Index_Term|null

   152      */

   153     public function currentTerm()

   154     {

   155         return $this->_lastTerm;

   156     }

   157 

   158     /**

   159      * Close terms stream

   160      *

   161      * Should be used for resources clean up if stream is not read up to the end

   162      */

   163     public function closeTermsStream()

   164     {

   165         while (($termStream = $this->_termsStreamQueue->pop()) !== null) {

   166             $termStream->closeTermsStream();

   167         }

   168 

   169         $this->_termsStreamQueue = null;

   170         $this->_lastTerm         = null;

   171     }

   172 }