Db.php

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<?php
 
define('CAS_PGT_STORAGE_DB_DEFAULT_TABLE', 'cas_pgts');
 
class CAS_PGTStorage_Db extends CAS_PGTStorage_AbstractStorage
{
    private $_pdo;
 
    private function _getPdo()
    {
        return $this->_pdo;
    }
 
    private $_dsn;
    private $_username;
    private $_password;
    private $_table_options;
 
    private $_table;
 
    private function _getTable()
    {
        return $this->_table;
    }
 
    // ########################################################################
    //  DEBUGGING
    // ########################################################################
 
    public function getStorageType()
    {
        return "db";
    }
 
    public function getStorageInfo()
    {
        return 'table=`'.$this->_getTable().'\'';
    }
 
    // ########################################################################
    //  CONSTRUCTOR
    // ########################################################################
 
    public function __construct(
        $cas_parent, $dsn_or_pdo, $username='', $password='', $table='',
        $driver_options=null
    ) {
        phpCAS::traceBegin();
        // call the ancestor's constructor
        parent::__construct($cas_parent);
 
        // set default values
        if ( empty($table) ) {
            $table = CAS_PGT_STORAGE_DB_DEFAULT_TABLE;
        }
        if ( !is_array($driver_options) ) {
            $driver_options = array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION);
        }
 
        // store the specified parameters
        if ($dsn_or_pdo instanceof PDO) {
            $this->_pdo = $dsn_or_pdo;
        } else {
            $this->_dsn = $dsn_or_pdo;
            $this->_username = $username;
            $this->_password = $password;
            $this->_driver_options = $driver_options;
        }
 
        // store the table name
        $this->_table = $table;
 
        phpCAS::traceEnd();
    }
 
    // ########################################################################
    //  INITIALIZATION
    // ########################################################################
 
    public function init()
    {
        phpCAS::traceBegin();
        // if the storage has already been initialized, return immediatly
        if ($this->isInitialized()) {
            return;
        }
 
        // initialize the base object
        parent::init();
 
        // create the PDO object if it doesn't exist already
        if (!($this->_pdo instanceof PDO)) {
            try {
                $this->_pdo = new PDO(
                    $this->_dsn, $this->_username, $this->_password,
                    $this->_driver_options
                );
            }
            catch(PDOException $e) {
                phpCAS::error('Database connection error: ' . $e->getMessage());
            }
        }
 
        phpCAS::traceEnd();
    }
 
    // ########################################################################
    //  PDO database interaction
    // ########################################################################
 
    private $_errMode;
 
    private function _setErrorMode()
    {
        // get PDO object and enable exception error mode
        $pdo = $this->_getPdo();
        $this->_errMode = $pdo->getAttribute(PDO::ATTR_ERRMODE);
        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    }
 
    private function _resetErrorMode()
    {
        // get PDO object and reset the error mode to what it was originally
        $pdo = $this->_getPdo();
        $pdo->setAttribute(PDO::ATTR_ERRMODE, $this->_errMode);
    }
 
    // ########################################################################
    //  database queries
    // ########################################################################
    // these queries are potentially unsafe because the person using this library
    // can set the table to use, but there is no reliable way to escape SQL
    // fieldnames in PDO yet
 
    protected function createTableSql()
    {
        return 'CREATE TABLE ' . $this->_getTable()
            . ' (pgt_iou VARCHAR(255) NOT NULL PRIMARY KEY, pgt VARCHAR(255) NOT NULL)';
    }
 
    protected function storePgtSql()
    {
        return 'INSERT INTO ' . $this->_getTable()
            . ' (pgt_iou, pgt) VALUES (:pgt_iou, :pgt)';
    }
 
    protected function retrievePgtSql()
    {
        return 'SELECT pgt FROM ' . $this->_getTable() . ' WHERE pgt_iou = :pgt_iou';
    }
 
    protected function deletePgtSql()
    {
        return 'DELETE FROM ' . $this->_getTable() . ' WHERE pgt_iou = :pgt_iou';
    }
 
    // ########################################################################
    //  PGT I/O
    // ########################################################################
 
    public function createTable()
    {
        phpCAS::traceBegin();
 
        // initialize this PGTStorage object if it hasn't been initialized yet
        if ( !$this->isInitialized() ) {
            $this->init();
        }
 
        // initialize the PDO object for this method
        $pdo = $this->_getPdo();
        $this->_setErrorMode();
 
        try {
            $pdo->beginTransaction();
 
            $query = $pdo->query($this->createTableSQL());
            $query->closeCursor();
 
            $pdo->commit();
        }
        catch(PDOException $e) {
            // attempt rolling back the transaction before throwing a phpCAS error
            try {
                $pdo->rollBack();
            }
            catch(PDOException $e) {
            }
            phpCAS::error('error creating PGT storage table: ' . $e->getMessage());
        }
 
        // reset the PDO object
        $this->_resetErrorMode();
 
        phpCAS::traceEnd();
    }
 
    public function write($pgt, $pgt_iou)
    {
        phpCAS::traceBegin();
 
        // initialize the PDO object for this method
        $pdo = $this->_getPdo();
        $this->_setErrorMode();
 
        try {
            $pdo->beginTransaction();
 
            $query = $pdo->prepare($this->storePgtSql());
            $query->bindValue(':pgt', $pgt, PDO::PARAM_STR);
            $query->bindValue(':pgt_iou', $pgt_iou, PDO::PARAM_STR);
            $query->execute();
            $query->closeCursor();
 
            $pdo->commit();
        }
        catch(PDOException $e) {
            // attempt rolling back the transaction before throwing a phpCAS error
            try {
                $pdo->rollBack();
            }
            catch(PDOException $e) {
            }
            phpCAS::error('error writing PGT to database: ' . $e->getMessage());
        }
 
        // reset the PDO object
        $this->_resetErrorMode();
 
        phpCAS::traceEnd();
    }
 
    public function read($pgt_iou)
    {
        phpCAS::traceBegin();
        $pgt = false;
 
        // initialize the PDO object for this method
        $pdo = $this->_getPdo();
        $this->_setErrorMode();
 
        try {
            $pdo->beginTransaction();
 
            // fetch the pgt for the specified pgt_iou
            $query = $pdo->prepare($this->retrievePgtSql());
            $query->bindValue(':pgt_iou', $pgt_iou, PDO::PARAM_STR);
            $query->execute();
            $pgt = $query->fetchColumn(0);
            $query->closeCursor();
 
            // delete the specified pgt_iou from the database
            $query = $pdo->prepare($this->deletePgtSql());
            $query->bindValue(':pgt_iou', $pgt_iou, PDO::PARAM_STR);
            $query->execute();
            $query->closeCursor();
 
            $pdo->commit();
        }
        catch(PDOException $e) {
            // attempt rolling back the transaction before throwing a phpCAS error
            try {
                $pdo->rollBack();
            }
            catch(PDOException $e) {
            }
            phpCAS::trace('error reading PGT from database: ' . $e->getMessage());
        }
 
        // reset the PDO object
        $this->_resetErrorMode();
 
        phpCAS::traceEnd();
        return $pgt;
    }
 
}
 
?>