1: <?php
  2: 
  3: namespace Budabot\Core;
  4: 
  5: use Exception;
  6: 
  7: /**
  8:  * @Instance
  9:  */
 10: class CacheManager {
 11: 
 12:     /** @Inject */
 13:     public $chatBot;
 14: 
 15:     /** @Inject */
 16:     public $http;
 17: 
 18:     /** @Inject */
 19:     public $util;
 20: 
 21:     private $cacheDir;
 22: 
 23:     /** @Setup */
 24:     public function init() {
 25:         $this->cacheDir = $this->chatBot->vars["cachefolder"];
 26: 
 27:         //Making sure that the cache folder exists
 28:         if (!dir($this->cacheDir)) {
 29:             mkdir($this->cacheDir, 0777);
 30:         }
 31:     }
 32: 
 33:     public function lookup($url, $groupName, $filename, $isValidCallback, $maxCacheAge = 86400, $forceUpdate = false) {
 34:         if (empty($groupName)) {
 35:             throw new Exception("Cache group name cannot be empty");
 36:         }
 37: 
 38:         $cacheResult = new CacheResult();
 39: 
 40:         // Check if a xml file of the person exists and if it is uptodate
 41:         if (!$forceUpdate && $this->cacheExists($groupName, $filename)) {
 42:             $cacheAge = $this->getCacheAge($groupName, $filename);
 43:             if ($cacheAge < $maxCacheAge) {
 44:                 $data = $this->retrieve($groupName, $filename);
 45:                 if (call_user_func($isValidCallback, $data)) {
 46:                     $cacheResult->data = $data;
 47:                     $cacheResult->cacheAge = $cacheAge;
 48:                     $cacheResult->usedCache = true;
 49:                     $cacheResult->oldCache = false;
 50:                     $cacheResult->success = true;
 51:                 } else {
 52:                     unset($data);
 53:                     $this->remove($groupName, $filename);
 54:                 }
 55:             }
 56:         }
 57: 
 58:         //If no old history file was found or it was invalid try to update it from url
 59:         if ($cacheResult->success !== true) {
 60:             $response = $this->http->get($url)->waitAndReturnResponse();
 61:             $data = $response->body;
 62:             if (call_user_func($isValidCallback, $data)) {
 63:                 $cacheResult->data = $data;
 64:                 $cacheResult->cacheAge = 0;
 65:                 $cacheResult->usedCache = false;
 66:                 $cacheResult->oldCache = false;
 67:                 $cacheResult->success = true;
 68:             } else {
 69:                 unset($data);
 70:             }
 71:         }
 72: 
 73:         //If the site was not responding or the data was invalid and a xml file exists get that one
 74:         if ($cacheResult->success !== true && $this->cacheExists($groupName, $filename)) {
 75:             $data = $this->retrieve($groupName, $filename);
 76:             if (call_user_func($isValidCallback, $data)) {
 77:                 $cacheResult->data = $data;
 78:                 $cacheResult->cacheAge = $this->getCacheAge($groupName, $filename);
 79:                 $cacheResult->usedCache = true;
 80:                 $cacheResult->oldCache = true;
 81:                 $cacheResult->success = true;
 82:             } else {
 83:                 unset($data);
 84:                 $this->remove($groupName, $filename);
 85:             }
 86:         }
 87: 
 88:         // if a new file was downloaded, save it in the cache
 89:         if ($cacheResult->usedCache === false && $cacheResult->success === true) {
 90:             $this->store($groupName, $filename, $cacheResult->data);
 91:         }
 92: 
 93:         return $cacheResult;
 94:     }
 95: 
 96:     public function store($groupName, $filename, $contents) {
 97:         if (!dir($this->cacheDir . '/' . $groupName)) {
 98:             mkdir($this->cacheDir . '/' . $groupName, 0777);
 99:         }
100: 
101:         $cacheFile = "$this->cacheDir/$groupName/$filename";
102: 
103:         // at least in windows, modifcation timestamp will not change unless this is done
104:         // not sure why that is the case -tyrence
105:         @unlink($cacheFile);
106: 
107:         $fp = fopen($cacheFile, "w");
108:         fwrite($fp, $contents);
109:         fclose($fp);
110:     }
111:     
112:     public function retrieve($groupName, $filename) {
113:         $cacheFile = "{$this->cacheDir}/$groupName/$filename";
114: 
115:         if (file_exists($cacheFile)) {
116:             return file_get_contents($cacheFile);
117:         } else {
118:             return null;
119:         }
120:     }
121: 
122:     public function getCacheAge($groupName, $filename) {
123:         $cacheFile = "$this->cacheDir/$groupName/$filename";
124: 
125:         if (file_exists($cacheFile)) {
126:             return time() - filemtime($cacheFile);
127:         } else {
128:             return null;
129:         }
130:     }
131: 
132:     public function cacheExists($groupName, $filename) {
133:         $cacheFile = "$this->cacheDir/$groupName/$filename";
134: 
135:         return file_exists($cacheFile);
136:     }
137: 
138:     public function remove($groupName, $filename) {
139:         $cacheFile = "$this->cacheDir/$groupName/$filename";
140: 
141:         @unlink($cacheFile);
142:     }
143: 
144:     public function getFilesInGroup($groupName) {
145:         $path = "$this->cacheDir/$groupName/";
146: 
147:         return $this->util->getFilesInDirectory($path);
148:     }
149: 
150:     public function getGroups() {
151:         return $this->util->getDirectoriesInDirectory($this->cacheDir);
152:     }
153: }
154: 
155: class CacheResult {
156:     public $success = false;
157:     public $usedCache = false;
158:     public $oldCache = false;
159:     public $cacheAge = 0;
160:     public $data;
161: }
162: