class pCache in Visitors 7.2

Hierarchy

• class \pCache

File

pChart/class/pCache.class.php, line 17

class pCache {
  var $CacheFolder;
  var $CacheIndex;
  var $CacheDB;

  /* Class creator */
  function pCache($Settings = "") {
    $CacheFolder = isset($Settings["CacheFolder"]) ? $Settings["CacheFolder"] : "cache";
    $CacheIndex = isset($Settings["CacheIndex"]) ? $Settings["CacheIndex"] : "index.db";
    $CacheDB = isset($Settings["CacheDB"]) ? $Settings["CacheDB"] : "cache.db";
    $this->CacheFolder = $CacheFolder;
    $this->CacheIndex = $CacheIndex;
    $this->CacheDB = $CacheDB;
    if (!file_exists($this->CacheFolder . "/" . $this->CacheIndex)) {
      touch($this->CacheFolder . "/" . $this->CacheIndex);
    }
    if (!file_exists($this->CacheFolder . "/" . $this->CacheDB)) {
      touch($this->CacheFolder . "/" . $this->CacheDB);
    }
  }

  /* Flush the cache contents */
  function flush() {
    if (file_exists($this->CacheFolder . "/" . $this->CacheIndex)) {
      unlink($this->CacheFolder . "/" . $this->CacheIndex);
      touch($this->CacheFolder . "/" . $this->CacheIndex);
    }
    if (file_exists($this->CacheFolder . "/" . $this->CacheDB)) {
      unlink($this->CacheFolder . "/" . $this->CacheDB);
      touch($this->CacheFolder . "/" . $this->CacheDB);
    }
  }

  /* Return the MD5 of the data array to clearly identify the chart */
  function getHash($Data, $Marker = "") {
    return md5($Marker . serialize($Data->Data));
  }

  /* Write the generated picture to the cache */
  function writeToCache($ID, $pChartObject) {

    /* Compute the paths */
    $TemporaryFile = $this->CacheFolder . "/tmp_" . rand(0, 1000) . ".png";
    $Database = $this->CacheFolder . "/" . $this->CacheDB;
    $Index = $this->CacheFolder . "/" . $this->CacheIndex;

    /* Flush the picture to a temporary file */
    imagepng($pChartObject->Picture, $TemporaryFile);

    /* Retrieve the files size */
    $PictureSize = filesize($TemporaryFile);
    $DBSize = filesize($Database);

    /* Save the index */
    $Handle = fopen($Index, "a");
    fwrite($Handle, $ID . "," . $DBSize . "," . $PictureSize . "," . time() . ",0      \r\n");
    fclose($Handle);

    /* Get the picture raw contents */
    $Handle = fopen($TemporaryFile, "r");
    $Raw = fread($Handle, $PictureSize);
    fclose($Handle);

    /* Save the picture in the solid database file */
    $Handle = fopen($Database, "a");
    fwrite($Handle, $Raw);
    fclose($Handle);

    /* Remove temporary file */
    unlink($TemporaryFile);
  }

  /* Remove object older than the specified TS */
  function removeOlderThan($Expiry) {
    $this
      ->dbRemoval(array(
      "Expiry" => $Expiry,
    ));
  }

  /* Remove an object from the cache */
  function remove($ID) {
    $this
      ->dbRemoval(array(
      "Name" => $ID,
    ));
  }

  /* Remove with specified criterias */
  function dbRemoval($Settings) {
    $ID = isset($Settings["Name"]) ? $Settings["Name"] : NULL;
    $Expiry = isset($Settings["Expiry"]) ? $Settings["Expiry"] : -(24 * 60 * 60);
    $TS = time() - $Expiry;

    /* Compute the paths */
    $Database = $this->CacheFolder . "/" . $this->CacheDB;
    $Index = $this->CacheFolder . "/" . $this->CacheIndex;
    $DatabaseTemp = $this->CacheFolder . "/" . $this->CacheDB . ".tmp";
    $IndexTemp = $this->CacheFolder . "/" . $this->CacheIndex . ".tmp";

    /* Single file removal */
    if ($ID != NULL) {

      /* Retrieve object informations */
      $Object = $this
        ->isInCache($ID, TRUE);

      /* If it's not in the cache DB, go away */
      if (!$Object) {
        return 0;
      }
    }

    /* Create the temporary files */
    if (!file_exists($DatabaseTemp)) {
      touch($DatabaseTemp);
    }
    if (!file_exists($IndexTemp)) {
      touch($IndexTemp);
    }

    /* Open the file handles */
    $IndexHandle = @fopen($Index, "r");
    $IndexTempHandle = @fopen($IndexTemp, "w");
    $DBHandle = @fopen($Database, "r");
    $DBTempHandle = @fopen($DatabaseTemp, "w");

    /* Remove the selected ID from the database */
    while (!feof($IndexHandle)) {
      $Entry = fgets($IndexHandle, 4096);
      $Entry = str_replace("\r", "", $Entry);
      $Entry = str_replace("\n", "", $Entry);
      $Settings = preg_split("/,/", $Entry);
      if ($Entry != "") {
        $PicID = $Settings[0];
        $DBPos = $Settings[1];
        $PicSize = $Settings[2];
        $GeneratedTS = $Settings[3];
        $Hits = $Settings[4];
        if ($Settings[0] != $ID && $GeneratedTS > $TS) {
          $CurrentPos = ftell($DBTempHandle);
          fwrite($IndexTempHandle, $PicID . "," . $CurrentPos . "," . $PicSize . "," . $GeneratedTS . "," . $Hits . "\r\n");
          fseek($DBHandle, $DBPos);
          $Picture = fread($DBHandle, $PicSize);
          fwrite($DBTempHandle, $Picture);
        }
      }
    }

    /* Close the handles */
    fclose($IndexHandle);
    fclose($IndexTempHandle);
    fclose($DBHandle);
    fclose($DBTempHandle);

    /* Remove the prod files */
    unlink($Database);
    unlink($Index);

    /* Swap the temp & prod DB */
    rename($DatabaseTemp, $Database);
    rename($IndexTemp, $Index);
  }
  function isInCache($ID, $Verbose = FALSE, $UpdateHitsCount = FALSE) {

    /* Compute the paths */
    $Index = $this->CacheFolder . "/" . $this->CacheIndex;

    /* Search the picture in the index file */
    $Handle = @fopen($Index, "r");
    while (!feof($Handle)) {
      $IndexPos = ftell($Handle);
      $Entry = fgets($Handle, 4096);
      if ($Entry != "") {
        $Settings = preg_split("/,/", $Entry);
        $PicID = $Settings[0];
        if ($PicID == $ID) {
          fclose($Handle);
          $DBPos = $Settings[1];
          $PicSize = $Settings[2];
          $GeneratedTS = $Settings[3];
          $Hits = intval($Settings[4]);
          if ($UpdateHitsCount) {
            $Hits++;
            if (strlen($Hits) < 7) {
              $Hits = $Hits . str_repeat(" ", 7 - strlen($Hits));
            }
            $Handle = @fopen($Index, "r+");
            fseek($Handle, $IndexPos);
            fwrite($Handle, $PicID . "," . $DBPos . "," . $PicSize . "," . $GeneratedTS . "," . $Hits . "\r\n");
            fclose($Handle);
          }
          if ($Verbose) {
            return array(
              "DBPos" => $DBPos,
              "PicSize" => $PicSize,
              "GeneratedTS" => $GeneratedTS,
              "Hits" => $Hits,
            );
          }
          else {
            return TRUE;
          }
        }
      }
    }
    fclose($Handle);

    /* Picture isn't in the cache */
    return FALSE;
  }

  /* Automatic output method based on the calling interface */
  function autoOutput($ID, $Destination = "output.png") {
    if (php_sapi_name() == "cli") {
      $this
        ->saveFromCache($ID, $Destination);
    }
    else {
      $this
        ->strokeFromCache($ID);
    }
  }
  function strokeFromCache($ID) {

    /* Get the raw picture from the cache */
    $Picture = $this
      ->getFromCache($ID);

    /* Do we have a hit? */
    if ($Picture == NULL) {
      return FALSE;
    }
    header('Content-type: image/png');
    echo $Picture;
    return TRUE;
  }
  function saveFromCache($ID, $Destination) {

    /* Get the raw picture from the cache */
    $Picture = $this
      ->getFromCache($ID);

    /* Do we have a hit? */
    if ($Picture == NULL) {
      return FALSE;
    }

    /* Flush the picture to a file */
    $Handle = fopen($Destination, "w");
    fwrite($Handle, $Picture);
    fclose($Handle);

    /* All went fine */
    return TRUE;
  }
  function getFromCache($ID) {

    /* Compute the path */
    $Database = $this->CacheFolder . "/" . $this->CacheDB;

    /* Lookup for the picture in the cache */
    $CacheInfo = $this
      ->isInCache($ID, TRUE, TRUE);

    /* Not in the cache */
    if (!$CacheInfo) {
      return NULL;
    }

    /* Get the database extended information */
    $DBPos = $CacheInfo["DBPos"];
    $PicSize = $CacheInfo["PicSize"];

    /* Extract the picture from the solid cache file */
    $Handle = @fopen($Database, "r");
    fseek($Handle, $DBPos);
    $Picture = fread($Handle, $PicSize);
    fclose($Handle);

    /* Return back the raw picture data */
    return $Picture;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
pCache::$CacheDB		property
pCache::$CacheFolder		property
pCache::$CacheIndex		property
pCache::autoOutput		function
pCache::dbRemoval		function
pCache::flush		function
pCache::getFromCache		function
pCache::getHash		function
pCache::isInCache		function
pCache::pCache		function
pCache::remove		function
pCache::removeOlderThan		function
pCache::saveFromCache		function
pCache::strokeFromCache		function
pCache::writeToCache		function