Limiting use of readdir in the idx_indexLengths function (v2).

Each searches on the wiki use this function. Scanning the index directory eachtime is time consuming with a constant series of disk access.
Switching a normal search to use file_exists 1 or more times, and not readdir all the directory.
Switching a wildcard search to use a lengths.idx file containing all the word lengths used in the wiki, file generated if a new configuration parameter $conf[readdircache] is not 0 and fixed to a time in second. Creation of a new function idx_listIndexLengths to do this part.

1 files changed, 121 insertions, 0 deletions

diff --git a/_test/cases/inc/indexer_idx_indexlengths.test.php b/_test/cases/inc/indexer_idx_indexlengths.test.php
new file mode 100644
index 000000000..d1339a111
--- /dev/null
+++ b/_test/cases/inc/indexer_idx_indexlengths.test.php
@@ -0,0 +1,121 @@
+<?php
+
+require_once DOKU_INC.'inc/indexer.php';
+
+class indexer_idx_indexlengths_test extends UnitTestCase {
+
+    /**
+     * Test the function with an array of one value
+     */
+    function test_oneWord(){
+        global $conf;
+        $filter[8] = array('dokuwiki');
+        // one word should return the index
+        $ref[] = 8;
+        sort($ref);
+        $result = idx_indexLengths(&$filter);
+        sort($result);
+        $this->assertIdentical($result, $ref);
+    }
+
+    /**
+     * Test the function with an array of values
+     */
+    function test_moreWords() {
+        global $conf;
+        $filter = array( 4 => array('test'), 8 => array('dokuwiki'), 7 => array('powered'));
+        // more words should return the indexes
+        $ref = array(4, 7, 8);
+        sort($ref);
+        $result = idx_indexLengths(&$filter);
+        sort($result);
+        $this->assertIdentical($result, $ref);
+    }
+
+    /**
+     * Test a minimal value in case of wildcard search
+     */
+    function test_minValue() {
+        global $conf;
+        $filter = 5;
+        // construction of the list of the index to compare
+        $dir = @opendir($conf['indexdir']);
+        $ref = array();
+        while (($f = readdir($dir)) !== false) {
+            if (substr($f,0,1) == 'i' && substr($f,-4) == '.idx'){
+                $i = substr($f,1,-4);
+                if (is_numeric($i) && $i >= $filter)
+                $ref[] = (int)$i;
+            }
+        }
+        closedir($dir);
+        sort($ref);
+        $result = idx_indexLengths(&$filter);
+        sort($result);
+        $this->assertIdentical($result, $ref);
+    }
+}
+
+class indexer_idx_indexlengths_time extends UnitTestCase {
+
+    /**
+     * Test the time improvments of the new function
+     * Time reference for 10000 call oneWords: 4,6s
+     * It's 90% faster
+     */
+    function test_oneWord(){
+        global $conf;
+        $filter[8] = array('dokuwiki');
+        $start = microtime(true);
+        for ($i = 0; $i < 10000; $i++) {
+            $result = idx_indexLengths(&$filter);
+        }
+        $end = microtime(true);
+        $time = $end - $start;
+        $timeref = 4.6*0.10; // actual execution time of 4,6s for 10000 calls
+        echo "1) 10% ref : $timeref -> $time \n";
+        $this->assertTrue($time < $timeref);
+    }
+
+    /**
+     * Test the time improvments of the new function
+     * Time reference for 10000 call moreWords: 4,6s
+     * It's 90% faster
+     */
+    function test_moreWords() {
+        global $conf;
+        $filter = array( 4 => array('test'), 8 => array('dokuwiki'), 7 => array('powered'));
+        // more words should return the indexes
+        $start = microtime(true);
+        for ($i = 0; $i < 10000; $i++) {
+            $result = idx_indexLengths(&$filter);
+        }
+        $end = microtime(true);
+        $time = $end - $start;
+        $timeref = 4.6*0.10; // actual execution time of 4,6s for 10000 calls
+        echo "2) 10% ref : $timeref -> $time \n";
+        $this->assertTrue($time < $timeref);
+    }
+
+    /**
+     * Test the time improvments of the new function
+     * Time reference for 10000 call on minValue: 4,9s
+     * Sould be at least 65% faster
+     * Test fail with no cache
+     */
+    function test_minValue() {
+        global $conf;
+        $filter = 5;
+        $start = microtime(true);
+        for ($i = 0; $i < 10000; $i++) {
+            $result = idx_indexLengths(&$filter);
+        }
+        $end = microtime(true);
+        $time = $end - $start;
+        $timeref = 4.9 * 0.35; // actual execution time of 4,9s for 10000 calls
+        echo "3) 35% ref : $timeref -> $time \n";
+        $this->assertTrue($time < $timeref);
+    }
+}
+
+//Setup VIM: ex: et ts=4 enc=utf-8 :