Add some logging to the caching.

In the process, streamline some of the caching-related code.
conormcd · Nov 20, 2014 · 832245a · 832245a
1 parent b6cd44a
commit 832245a
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Showing 9 changed files with 158 additions and 191 deletions.
diff --git a/controller/Controller.php b/controller/Controller.php
@@ -83,12 +83,14 @@ protected function content() {
         if ($model) {
             $key .= $model->eTag();
         }
-        $content = Cache::get($key);
-        if (!$content) {
-            $content = Mustache::render($view, $model);
-            Cache::set($key, $content, 86400 + rand(0, 3600));
-        }
-        return $content;
+
+        return Cache::run(
+            $key,
+            86400 + rand(0, 3600),
+            function () use ($view, $model) {
+                return Mustache::render($view, $model);
+            }
+        );
     }
 
     /**

diff --git a/lib/Cache.php b/lib/Cache.php
@@ -52,6 +52,32 @@ public static function clear() {
             apc_clear_cache('user');
         }
     }
+
+    /**
+     * Run some code and cache the result.
+     *
+     * @param string   $key      The key for the cache entry.
+     * @param int      $ttl      The life time for the cache entry.
+     * @param callable $callable The code to run and cache.
+     * @param array    $args     Arguments to pass to the cached function.
+     *
+     * @return mixed             The result of the wrapped, possibly from the
+     *                           cache.
+     */
+    public static function run($key, $ttl, $callable, $args = array()) {
+        $result = self::get($key);
+        if ($result === null) {
+            $start = microtime(true);
+            $result = call_user_func_array($callable, $args);
+            Logger::debug(
+                "Value recomputed for $key in " .
+                (microtime(true) - $start) .
+                " seconds."
+            );
+            self::set($key, $result, $ttl);
+        }
+        return $result;
+    }
 }
 
 ?>
diff --git a/lib/Flickr.php b/lib/Flickr.php
@@ -50,25 +50,27 @@ public function __construct($key, $secret, $user) {
      * @return array See {@link PhotoProvider#getAlbum()}
      */
     public function getAlbums() {
-        $key = 'FLICKR_ALBUMS';
-        $albums = Cache::get($key);
-        if (!$albums) {
-            $albums = array();
-            $response = $this->photosets->getList(
-                array('user_id' => $this->getCurrentUserNSID())
-            );
-            foreach ($response['photosets']['photoset'] as $set) {
-                $albums[] = new PhotoAlbumModel(
-                    $this,
-                    $set['id'],
-                    $set['title']['_content'],
-                    $set['date_create'],
-                    $set['primary']
+        $flickr = $this;
+        return Cache::run(
+            'FLICKR_ALBUMS',
+            3600 + rand(0, 300),
+            function () use ($flickr) {
+                $albums = array();
+                $response = $flickr->photosets->getList(
+                    array('user_id' => $flickr->getCurrentUserNSID())
                 );
+                foreach ($response['photosets']['photoset'] as $set) {
+                    $albums[] = new PhotoAlbumModel(
+                        $flickr,
+                        $set['id'],
+                        $set['title']['_content'],
+                        $set['date_create'],
+                        $set['primary']
+                    );
+                }
+                return $albums;
             }
-            Cache::set($key, $albums, 3600 + rand(0, 300));
-        }
-        return $albums;
+        );
     }
 
     /**
@@ -99,40 +101,42 @@ public function getAlbum($album_short_name) {
      * @return array See {@link PhotoProvider#getAlbum()}
      */
     public function getPhotos($album) {
-        $key = 'FLICKR_PHOTOS_' . $album->slug();
-        $photos = Cache::get($key);
-        if (!$photos) {
-            $photos = array();
-            $index = 0;
-            $result = $this->photosets->getPhotos(
-                array(
-                    'photoset_id' => $album->albumID(),
-                    'extras' => 'url_o,url_q,url_c,url_z,url_m'
-                )
-            );
-            foreach ($result['photoset']['photo'] as $photo) {
-                $sizes = array(
-                    'thumbnail' => $photo['url_q'],
-                    'fullsize' => $photo['url_o']
+        $flickr = $this;
+        return Cache::run(
+            'FLICKR_PHOTOS_' . $album->slug(),
+            $this->albumCacheLifetime($album),
+            function () use ($flickr, $album) {
+                $photos = array();
+                $index = 0;
+                $result = $flickr->photosets->getPhotos(
+                    array(
+                        'photoset_id' => $album->albumID(),
+                        'extras' => 'url_o,url_q,url_c,url_z,url_m'
+                    )
                 );
-                foreach (array('c', 'z', 'm', 'o') as $size) {
-                    if (array_key_exists("url_$size", $photo)) {
-                        $sizes['large'] = $photo["url_$size"];
-                        break;
+                foreach ($result['photoset']['photo'] as $photo) {
+                    $sizes = array(
+                        'thumbnail' => $photo['url_q'],
+                        'fullsize' => $photo['url_o']
+                    );
+                    foreach (array('c', 'z', 'm', 'o') as $size) {
+                        if (array_key_exists("url_$size", $photo)) {
+                            $sizes['large'] = $photo["url_$size"];
+                            break;
+                        }
                     }
+                    $photos[$index] = new PhotoModel(
+                        $album,
+                        $photo['id'],
+                        $index,
+                        $photo['title'],
+                        $sizes
+                    );
+                    $index++;
                 }
-                $photos[$index] = new PhotoModel(
-                    $album,
-                    $photo['id'],
-                    $index,
-                    $photo['title'],
-                    $sizes
-                );
-                $index++;
+                return $photos;
             }
-            Cache::set($key, $photos, $this->albumCacheLifetime($album));
-        }
-        return $photos;
+        );
     }
 
     /**
@@ -161,17 +165,18 @@ private function albumCacheLifetime($album) {
      *
      * @return string The NSID for the current user.
      */
-    private function getCurrentUserNSID() {
-        $key = 'FLICKR_API_NSID_' . $this->_username;
-        $nsid = Cache::get($key);
-        if (!$nsid) {
-            $response = $this->people->findByUsername(
-                array('username' => $this->_username)
-            );
-            $nsid = $response['user']['nsid'];
-            Cache::set($key, $nsid, 0);
-        }
-        return $nsid;
+    public function getCurrentUserNSID() {
+        $flickr = $this;
+        return Cache::run(
+            'FLICKR_API_NSID_' . $this->_username,
+            0,
+            function () use ($flickr) {
+                $response = $flickr->people->findByUsername(
+                    array('username' => $this->_username)
+                );
+                return $response['user']['nsid'];
+            }
+        );
     }
 
     /**
@@ -184,21 +189,23 @@ private function getCurrentUserNSID() {
      */
     public function request($method, $args=array()) {
         $url = $this->constructAPIURL($method, $args);
-        $key = 'FLICKR_API_REQUEST' . md5($url);
-        $result = Cache::get($key);
-        if (!$result) {
-            $result = JSON::decode($this->_http_client->get($url));
-            if ($result !== null) {
-                if ($result['stat'] == 'fail') {
-                    throw new Exception(
-                        $result['message'],
-                        $this->mapErrorCode($method, $result['code'])
-                    );
+        $flickr = $this;
+        return Cache::run(
+            'FLICKR_API_REQUEST' . md5($url),
+            3600 + rand(0, 300),
+            function () use ($flickr, $method, $url) {
+                $result = JSON::decode($flickr->_http_client->get($url));
+                if ($result !== null) {
+                    if ($result['stat'] == 'fail') {
+                        throw new Exception(
+                            $result['message'],
+                            $flickr->mapErrorCode($method, $result['code'])
+                        );
+                    }
                 }
-                Cache::set($key, $result, 3600 + rand(0, 300));
+                return $result;
             }
-        }
-        return $result;
+        );
     }
 
     /**
@@ -249,7 +256,7 @@ private function constructAPIURL($method, $args=array()) {
      * @return int The most appropriate HTTP status code or 500 if none can be
      *             calculated.
      */
-    private function mapErrorCode($method, $flickr_error_number) {
+    public function mapErrorCode($method, $flickr_error_number) {
         $error_map = array(
             'flickr.people.findByUsername' => array(1 => 404, 105 => 503),
             'flickr.photosets.getList' => array(1 => 404, 105 => 503),

diff --git a/lib/GitHub.php b/lib/GitHub.php
@@ -58,15 +58,16 @@ public function repos() {
      * @return array The decoded form of the JSON which was returned.
      */
     private function get($path) {
-        $key = 'GITHUB_API_REQUEST_' . md5($path);
-        $result = Cache::get($key);
-        if (!$result) {
-            $result = JSON::decode(
-                $this->_http_client->get("https://api.github.com$path")
-            );
-            Cache::set($key, $result, 3600 + rand(0, 300));
-        }
-        return $result;
+        $client = $this->_http_client;
+        return Cache::run(
+            'GITHUB_API_REQUEST_' . md5($path),
+            3600 + rand(0, 300),
+            function () use ($client, $path) {
+                return JSON::decode(
+                    $client->get("https://api.github.com$path")
+                );
+            }
+        );
     }
 }
 

diff --git a/lib/SyntaxHighlighter.php b/lib/SyntaxHighlighter.php
@@ -17,14 +17,15 @@ class SyntaxHighlighter {
      */
     public static function highlight($matches) {
         $key = join('_', array('syntax', $matches[1], md5($matches[2])));
-        $result = Cache::get($key);
-        if ($result === null) {
-            $geshi = new GeSHi(trim($matches[2]), $matches[1]);
-            $geshi->set_overall_class('codeblock');
-            $result = $geshi->parse_code();
-            Cache::set($key, $result, 0);
-        }
-        return $result;
+        return Cache::run(
+            $key,
+            0,
+            function () use ($matches) {
+                $geshi = new GeSHi(trim($matches[2]), $matches[1]);
+                $geshi->set_overall_class('codeblock');
+                return $geshi->parse_code();
+            }
+        );
     }
 }
 

diff --git a/model/BlogEntryModel.php b/model/BlogEntryModel.php
@@ -171,7 +171,7 @@ public function eTag() {
      */
     private function html() {
         $markdown = file_get_contents($this->_file);
-        return $this->cache(
+        return Cache::run(
             'blog_html_' . md5($markdown),
             0,
             function () use ($markdown) {

diff --git a/model/FrontPageModel.php b/model/FrontPageModel.php
@@ -34,36 +34,36 @@ public function link() {
      *               of data we fetch from.
      */
     public function all() {
-        $key = 'FRONT_PAGE_DATA';
-        $all = Cache::get($key);
-        if ($all) {
-            return $all;
-        }
-        $all = array();
+        return Cache::run(
+            'FRONT_PAGE_DATA',
+            $this->ttl(),
+            function () {
+                $all = array();
 
-        // Mix in the blog
-        $blog = new BlogModel(null, null, null, null, 1, -1);
-        foreach ($blog->entries() as $blog_entry) {
-            $all[$blog_entry->timestamp()] = $blog_entry;
-        }
+                // Mix in the blog
+                $blog = new BlogModel(null, null, null, null, 1, -1);
+                foreach ($blog->entries() as $blog_entry) {
+                    $all[$blog_entry->timestamp()] = $blog_entry;
+                }
 
-        // Mix in the photo albums
-        $photos = new PhotosModel(null, 1, -1);
-        foreach ($photos->albums() as $album) {
-            $all[$album->timestamp()] = $album;
-        }
+                // Mix in the photo albums
+                $photos = new PhotosModel(null, 1, -1);
+                foreach ($photos->albums() as $album) {
+                    $all[$album->timestamp()] = $album;
+                }
 
-        // Mix in the photos from Instagram
-        $instagram = Instagram::getInstance();
-        foreach ($instagram->getStream() as $photo) {
-            $all[$photo['timestamp']] = $photo;
-        }
+                // Mix in the photos from Instagram
+                $instagram = Instagram::getInstance();
+                foreach ($instagram->getStream() as $photo) {
+                    $all[$photo['timestamp']] = $photo;
+                }
 
-        krsort($all);
-        $all = array_values($all);
-        Cache::set($key, $all, $this->ttl());
+                krsort($all);
+                $all = array_values($all);
 
-        return $all;
+                return $all;
+            }
+        );
     }
 
     /**

diff --git a/model/Model.php b/model/Model.php
@@ -45,26 +45,6 @@ public function newRelicJSHeader() {
     public function ttl() {
         return 0;
     }
-
-    /**
-     * Wrap a chunk of code in some caching.
-     *
-     * @param string   $key      The key for the cache entry.
-     * @param int      $ttl      The life time for the cache entry.
-     * @param callable $callable The code to wrap in caching.
-     * @param array    $args     Arguments to pass to the cached function.
-     *
-     * @return mixed             The result of the wrapped code, possibly from
-     *                           the cache.
-     */
-    protected function cache($key, $ttl, $callable, $args = array()) {
-        $result = Cache::get($key);
-        if ($result === null) {
-            $result = call_user_func_array($callable, $args);
-            Cache::set($key, $result, $ttl);
-        }
-        return $result;
-    }
 }
 
 ?>