Proyectos de Subversion Moodle

<?php
/*
pCache - speed up the rendering by caching up the pictures

Version     : 2.1.4
Made by     : Jean-Damien POGOLOTTI
Last Update : 19/01/2014

This file can be distributed under the license you can find at :

http://www.pchart.net/license

You can find the whole class documentation on the pChart web site.
*/
/* pData class definition */

class pCache
{
        var $CacheFolder;
        var $CacheIndex;
        var $CacheDB;
        /* Class creator */
        function __construct(array $Settings = [])
        {
                
                #if (!is_dir("cache")){
                #       mkdir("cache", 0775);
                #}
                
                $this->CacheFolder = isset($Settings["CacheFolder"]) ? $Settings["CacheFolder"] : "cache";
                
                $this->CacheIndex = isset($Settings["CacheIndex"]) ? $Settings["CacheIndex"] : "index.db";
                $this->CacheIndex = $this->CacheFolder . "/" . $this->CacheIndex;
                
                $this->CacheDB = isset($Settings["CacheDB"]) ? $Settings["CacheDB"] : "cache.db";
                $this->CacheDB = $this->CacheFolder . "/" . $this->CacheDB;
                
                if (!file_exists($this->CacheIndex)) {
                        touch($this->CacheIndex);
                }

                if (!file_exists($this->CacheDB)) {
                        touch($this->CacheDB);
                }
        }

        /* Flush the cache contents */
        function flush()
        {
                file_put_contents($this->CacheIndex, "");
                file_put_contents($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";

                /* Flush the picture to a temporary file */
                imagepng($pChartObject->Picture, $TemporaryFile);
                /* Retrieve the files size */
                $PictureSize = filesize($TemporaryFile);
                $DBSize = filesize($this->CacheDB);
                /* Save the index */
                $Handle = fopen($this->CacheIndex, "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 */
                $Handle = fopen($this->CacheDB, "a");
                fwrite($Handle, $Raw);
                fclose($Handle);
                /* Remove temporary file */
                unlink($TemporaryFile);
        }

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

        /* Remove an object from the cache */
        function remove($ID)
        {
                $this->dbRemoval(["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 */
                $DatabaseTemp = $this->CacheDB . ".tmp";
                $IndexTemp = $this->CacheIndex . ".tmp";
                /* Single file removal */
                if ($ID != NULL) {
                        /* If it's not in the cache DB, go away */
                        if (!$this->isInCache($ID, TRUE)) {
                                return 0;
                        }
                }

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

                if (!file_exists($IndexTemp)) {
                        touch($IndexTemp);
                }

                /* Open the file handles */
                $IndexHandle = fopen($this->CacheIndex, "r");
                $IndexTempHandle = fopen($IndexTemp, "w");
                $DBHandle = fopen($this->CacheDB, "r");
                $DBTempHandle = fopen($DatabaseTemp, "w");
                /* Remove the selected ID from the database */
                if ($IndexHandle && $IndexTempHandle && $DBHandle && $DBTempHandle) {
                        while (!feof($IndexHandle)) {
                                $Entry = fgets($IndexHandle, 4096);
                                $Entry = str_replace("\r", "", $Entry);
                                $Entry = str_replace("\n", "", $Entry);
                                $Settings = explode(",", $Entry);
                                if ($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($this->CacheDB);
                unlink($this->CacheIndex);
                /* Swap the temp & prod DB */
                rename($DatabaseTemp, $this->CacheDB);
                rename($IndexTemp, $this->CacheIndex);
        }

        function isInCache($ID, $Verbose = FALSE, $UpdateHitsCount = FALSE)
        {
                /* Search the picture in the index file */
                $Handle = fopen($this->CacheIndex, "r");
                if ($Handle){
                        while (!feof($Handle)) {
                                $IndexPos = ftell($Handle);
                                $Entry = fgets($Handle, 4096);
                                if ($Entry != "") {
                                        $Settings = explode(",", $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));
                                                        }

                                                        $Handle = fopen($this->CacheIndex, "r+");
                                                        fseek($Handle, $IndexPos);
                                                        fwrite($Handle, $PicID . "," . $DBPos . "," . $PicSize . "," . $GeneratedTS . "," . $Hits . "\r\n");
                                                        fclose($Handle);
                                                }

                                                if ($Verbose) {
                                                        return ["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 == FALSE) {
                        return FALSE;
                }

                header('Content-type: image/png');
                echo $Picture;
        }

        function saveFromCache($ID, $Destination)
        {
                /* Get the raw picture from the cache */
                $Picture = $this->getFromCache($ID);
                /* Do we have a hit? */
                if ($Picture == FALSE) {
                        return FALSE;
                }

                /* Flush the picture to a file */
                file_put_contents($Destination, $Picture);
        }

        function getFromCache($ID)
        {
                /* Lookup for the picture in the cache */
                $CacheInfo = $this->isInCache($ID, TRUE, TRUE);
                /* Not in the cache */
                if (!$CacheInfo) { 
                        # Momchil: fread returns FALSE on failure. Return FALSE here as well and not NULL
                        return FALSE;
                }

                /* Get the database extended information */
                $DBPos = $CacheInfo["DBPos"];
                $PicSize = $CacheInfo["PicSize"];
                /* Extract the picture from the solid cache file */
                $Handle = fopen($this->CacheDB, "r");
                fseek($Handle, $DBPos);
                $Picture = fread($Handle, $PicSize);
                fclose($Handle);
                /* Return back the raw picture data */
                return $Picture;
        }
}

?>