From 755734ee8825b90993249b6fef87a59f1ac755c3 Mon Sep 17 00:00:00 2001
From: Karl 'vollmerk' Vollmer <vollmer@ampache.org>
Date: Fri, 27 Jul 2007 23:18:40 +0000
Subject: stupid vollmer no biscut

---
 lib/album.lib.php | 58 +++++++++++++++++++++++++------------------------------
 1 file changed, 26 insertions(+), 32 deletions(-)

(limited to 'lib/album.lib.php')

diff --git a/lib/album.lib.php b/lib/album.lib.php
index c484eca4..6edfc932 100644
--- a/lib/album.lib.php
+++ b/lib/album.lib.php
@@ -79,42 +79,36 @@ function get_image_from_source($data) {
  * This returns a random number of albums from the catalogs
  * this is used by the index to return some 'potential' albums to play
  */
-function get_random_albums($count=6) {
-        // There's a slight chance with this logic that the number of albums
-        // returned will be less than the number requested if the id's for the
-        // albums have signifigant gaps, but the speed increase is probably
-        // worth it
-        // - Vlet
-
-        $sql = 'SELECT ';
-	
-        for ($i = 0; $i < $count; $i++) {
-                if ($i > 0) $sql .= ', ';
-		
-                $sql .= 'floor(rand() * count(id))';
-        }
-	$sql .= ' FROM `album`';
-		
-        $db_results = Dba::query($sql);
-	
-        $sql = '';
-	
-	$row = Dba::fetch_assoc($db_results);
-	
-        for ($i = 0; $i < $count; $i++) {
-                if ($i > 0) $sql .= ' UNION ';
+function get_random_albums($count='') { 
+
+	if (!$count) { $count = 5; } 
 
-                $sql .= "SELECT * FROM (SELECT `id` FROM `album` LIMIT " . $row[$i] . ",1) t".$i;
-        }
+	$count = Dba::escape($count); 
 
-        $db_results = Dba::query($sql);
+	// We avoid a table scan by using the id index and then using a rand to pick a row #
+	$sql = "SELECT `id` FROM `album`";
+	$db_results = Dba::query($sql); 
 
-        $results = array();
+	while ($r = Dba::fetch_assoc($db_results)) { 
+		$albums[] = $r['id'];
+	} 
+
+	$total = count($albums); 
 
-        while($row = Dba::fetch_row($db_results)) {
-                $results[] = $row[0];
-        }
+	if ($total < ($count+2)) { return array(); } 
+
+	for ($i=0; $i <= $count; $i++) { 
+		$tries++; 
+		$record = rand(0,$total); 
+		if (isset($results[$record]) || !$albums[$record]) { $i--; continue; } 
+		else { 
+			$results[$record] = $albums[$record]; 
+		} 
+		if ($tries > 50) { return array(); } 
+	} // end for 
+	
+	return $results; 
 
-        return $results;
 } // get_random_albums
+
 ?>
-- 
cgit