Refactoring of code base - modularized code, introduced configuration, started working on a PDO based DB connector

lib/zerobin_data.php

@@ -0,0 +1,283 @@
+<?php
+/**
+ * ZeroBin
+ *
+ * a zero-knowledge paste bin
+ *
+ * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
+ * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
+ * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
+ * @version   0.15
+ */
+
+/**
+ * zerobin_data
+ *
+ * Model for data access, implemented as a singleton.
+ */
+class zerobin_data
+{
+    /*
+     * @access private
+     * @static
+     * @var string directory where data is stored
+     */
+    private static $_dir = 'data/';
+
+    /**
+     * singleton instance
+     *
+     * @access private
+     * @static
+     * @var zerobin
+     */
+    private static $_instance = null;
+
+    /**
+     * enforce singleton, disable constructor
+     *
+     * Instantiate using {@link getInstance()}, zerobin is a singleton object.
+     *
+     * @access protected
+     */
+    protected function __construct() {}
+
+    /**
+     * enforce singleton, disable cloning
+     *
+     * Instantiate using {@link getInstance()}, zerobin is a singleton object.
+     *
+     * @access private
+     */
+    private function __clone() {}
+
+    /**
+     * get instance of singleton
+     *
+     * @access public
+     * @static
+     * @return zerobin
+     */
+    public static function getInstance($options)
+    {
+        // if needed initialize the singleton
+        if(null === self::$_instance) {
+            self::$_instance = new self;
+            self::_init();
+        }
+        if (
+        	is_array($options) && 
+        	array_key_exists('dir', $options)
+        ) self::$_dir = $options['dir'];
+        return self::$_instance;
+    }
+
+    /**
+     * Create a paste.
+     *
+     * @access public
+     * @param  string $pasteid
+     * @param  array  $paste
+     * @return int|false
+     */
+    public function create($pasteid, $paste)
+    {
+        $storagedir = self::_dataid2path($pasteid);
+        if (is_file($storagedir . $pasteid)) return false;
+        if (!is_dir($storagedir)) mkdir($storagedir, 0705, true);
+        return file_put_contents($storagedir . $pasteid, json_encode($paste));
+    }
+
+    /**
+     * Read a paste.
+     *
+     * @access public
+     * @param  string $pasteid
+     * @return string
+     */
+    public function read($pasteid)
+    {
+        if(!$this->exists($pasteid)) return json_decode(
+            '{"data":"","meta":{"burnafterreading":true,"postdate":0}}'
+        );
+        return json_decode(
+            file_get_contents(self::_dataid2path($pasteid) . $pasteid)
+        );
+    }
+
+    /**
+     * Delete a paste and its discussion.
+     *
+     * @access public
+     * @param  string $pasteid
+     * @return void
+     */
+    public function delete($pasteid)
+    {
+        // Delete the paste itself.
+        unlink(self::_dataid2path($pasteid) . $pasteid);
+
+        // Delete discussion if it exists.
+        $discdir = self::_dataid2discussionpath($pasteid);
+        if (is_dir($discdir))
+        {
+            // Delete all files in discussion directory
+            $dir = dir($discdir);
+            while (false !== ($filename = $dir->read()))
+            {
+                if (is_file($discdir.$filename)) unlink($discdir.$filename);
+            }
+            $dir->close();
+
+            // Delete the discussion directory.
+            rmdir($discdir);
+        }
+    }
+
+    /**
+     * Test if a paste exists.
+     *
+     * @access public
+     * @param  string $dataid
+     * @return void
+     */
+    public function exists($pasteid)
+    {
+        return is_file(self::_dataid2path($pasteid) . $pasteid);
+    }
+
+    /**
+     * Create a comment in a paste.
+     *
+     * @access public
+     * @param  string $pasteid
+     * @param  string $parentid
+     * @param  string $commentid
+     * @param  array  $comment
+     * @return int|false
+     */
+    public function createComment($pasteid, $parentid, $commentid, $comment)
+    {
+        $storagedir = self::_dataid2discussionpath($pasteid);
+        $filename = $pasteid . '.' . $commentid . '.' . $parentid;
+        if (is_file($storagedir . $filename)) return false;
+        if (!is_dir($storagedir)) mkdir($storagedir, 0705, true);
+        return file_put_contents($storagedir . $filename, json_encode($comment));
+    }
+
+    /**
+     * Read all comments of paste.
+     *
+     * @access public
+     * @param  string $pasteid
+     * @return array
+     */
+    public function readComments($pasteid)
+    {
+        $comments = array();
+        $discdir = self::_dataid2discussionpath($pasteid);
+        if (is_dir($discdir))
+        {
+            // Delete all files in discussion directory
+            $dir = dir($discdir);
+            while (false !== ($filename = $dir->read()))
+            {
+                // Filename is in the form pasteid.commentid.parentid:
+                // - pasteid is the paste this reply belongs to.
+                // - commentid is the comment identifier itself.
+                // - parentid is the comment this comment replies to (It can be pasteid)
+                if (is_file($discdir.$filename))
+                {
+                    $comment = json_decode(file_get_contents($discdir.$filename));
+                    $items = explode('.', $filename);
+                    // Add some meta information not contained in file.
+                    $comment->meta->commentid=$items[1];
+                    $comment->meta->parentid=$items[2];
+
+                    // Store in array
+                    $comments[$comment->meta->postdate]=$comment;
+                }
+            }
+            $dir->close();
+
+            // Sort comments by date, oldest first.
+            ksort($comments);
+        }
+        return $comments;
+    }
+
+    /**
+     * Test if a comment exists.
+     *
+     * @access public
+     * @param  string $dataid
+     * @param  string $parentid
+     * @param  string $commentid
+     * @return void
+     */
+    public function existsComment($pasteid, $parentid, $commentid)
+    {
+        return is_file(
+            self::_dataid2discussionpath($pasteid) .
+            $pasteid . '.' . $dataid . '.' . $parentid
+        );
+    }
+
+    /**
+     * initialize zerobin
+     *
+     * @access private
+     * @static
+     * @return void
+     */
+    private static function _init()
+    {
+        if (defined('PATH')) self::$_dir = PATH . self::$_dir;
+
+        // Create storage directory if it does not exist.
+        if (!is_dir(self::$_dir))
+        {
+            mkdir(self::$_dir, 0705);
+            file_put_contents(
+                self::$_dir . '.htaccess',
+                'Allow from none' . PHP_EOL .
+                'Deny from all'. PHP_EOL
+            );
+        }
+    }
+
+    /**
+     * Convert paste id to storage path.
+     *
+     * The idea is to creates subdirectories in order to limit the number of files per directory.
+     * (A high number of files in a single directory can slow things down.)
+     * eg. "f468483c313401e8" will be stored in "data/f4/68/f468483c313401e8"
+     * High-trafic websites may want to deepen the directory structure (like Squid does).
+     *
+     * eg. input 'e3570978f9e4aa90' --> output 'data/e3/57/'
+     *
+     * @access private
+     * @static
+     * @param  string $dataid
+     * @return void
+     */
+    private static function _dataid2path($dataid)
+    {
+        return self::$_dir . substr($dataid,0,2) . '/' . substr($dataid,2,2) . '/';
+    }
+
+    /**
+     * Convert paste id to discussion storage path.
+     *
+     * eg. input 'e3570978f9e4aa90' --> output 'data/e3/57/e3570978f9e4aa90.discussion/'
+     *
+     * @access private
+     * @static
+     * @param  string $dataid
+     * @return void
+     */
+    private static function _dataid2discussionpath($dataid)
+    {
+        return self::_dataid2path($dataid) . $dataid . '.discussion/';
+    }
+}