From 01ceb7a82ba4ed0f88113d917c8180992f82ce95 Mon Sep 17 00:00:00 2001
From: "Edward Z. Yang" <edwardzyang@thewritingpot.com>
Date: Tue, 4 Sep 2007 19:28:49 +0000
Subject: [PATCH] Make SVN queries reuse cached entries.

git-svn-id: http://htmlpurifier.org/svnroot@1413 48356398-32a2-884e-a903-53898d9a118a
---
 TODO.txt      |  3 ---
 functions.php | 10 +++++++++-
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/TODO.txt b/TODO.txt
index eb69b8e..6e7beab 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -16,9 +16,6 @@ DOMFilter
 - Temporary different base URL (sorta like AbsolutePath, but more flexible)
 - Notify when there are BROKEN LINKS!
 
-DOMFilter_RSSFromSVN
-- Incremental updates of cache
-
 TextFilter
 - Tidy formatting (kinda useless, since Tidy isn't available on our server)
 - Alternate markup language: Markdown (.mktext), simplified HTML (.sxhtml)
diff --git a/functions.php b/functions.php
index e512d3d..7eb0511 100644
--- a/functions.php
+++ b/functions.php
@@ -159,17 +159,25 @@ function svn_log_limit($repos_url, $limit, $page = null) {
     if ($limit <= 0) return array();
     // attempt the cache
     $cache_filename = 'xhtml-compiler/cache/svn/log/' . md5($repos_url) . '.ser';
+    $cached_rev = false;
     if ($page && file_exists($cache_filename)) {
         $logs = unserialize(file_get_contents($cache_filename));
+        $cached_rev = $logs[0]['rev'];
         // determine current revision number
         $rev = $page->getSVNRevision();
-        if ($logs[0]['rev'] == $rev) return $logs;
+        if ($cached_rev == $rev && count($logs) == $limit) return $logs;
     }
     // -q flag used to prevent server from sending log messages
+    // most recent is retrieved first
     $output = shell_exec("svn log -q --limit $limit $repos_url");
     preg_match_all('/^r(\d+) /m', $output, $matches);
     $ret = array();
     foreach ($matches[1] as $rev) {
+        // reuse previously cached entries
+        if ($rev <= $cached_rev) {
+            $ret[] = array_shift($logs);
+            continue;
+        }
         $log = svn_log($repos_url, (int) $rev);
         $ret[] = $log[0]; // log is only one item long
     }
-- 
2.11.4.GIT