<?
/******************************************************************
class Db
Description:
A redundant MySQL connection class
If RANDOMIZE is set and SLAVES are provided
all SELECT statements will be run off a random mysql connections.
If no slaves are present just use the MASTER connection
Author: Vermonster SA
Maintainer: Jay Powers
Email: jay@vermonster.com
Purpose: Provide an OO API for redundant MySQL connection
This software is now distributed under the terms of the
Lesser GNU Public License
$Id: db.class.php,v 1.2 2002/05/03 15:16:28 brian.kaney Exp $
Usage:
// Connection to MASTER
$object = new Db("10.0.0.1","login","pass","test");
$slaves = array (
array(host=>"192.168.0.2",user=>"foo",pass=>"bar",db=>"test"),
array(host=>"192.168.0.10",user=>"foo",pass=>"bar",db=>"test")
);
// Add the slaves into the mix and trigger random selects
$object->set_slaves($slaves,true);
$result = $object->db_query("SELECT username,email1 FROM users");
******************************************************************/
class Db {
// Define all global vars
var $MASTER = array(); // Master database
var $SLAVES = array(); // Slave databases
var $TIMEOUT;
var $SOCKET;
var $PORT;
var $RANDOMIZE;
var $CK = array(); // Array of
function Db ($master, $login, $pass, $db, $timeout=5, $socket=true, $port=3306) {
// Initialize Global vars
$this->TIMEOUT = $timeout;
$this->SOCKET = $socket;
$this->PORT = $port;
$this->MASTER = array('host' => $master, 'user' => $login, 'pass' => $pass, 'db' =>$db);
}
function set_slaves($slaves, $randomize=false) {
/* Set all the slaves
* merge MASTER and SLAVES for random SELECTS */
$this->SLAVES = $slaves;
$this->RANDOMIZE = $randomize;
array_unshift($this->SLAVES, $this->MASTER);
}
function db_connect($db) {
/* This function is called from db_query.
* We need to see what type of query is being run */
if ($fp = fsockopen($db['host'], $this->PORT, &$errno, &$errstr, $this->TIMEOUT)) {
if (!$this->LINK_ID = mysql_pconnect($db['host'], $db['user'], $db['pass'])) {
echo "<h4>Can't connect to" . $db['host'] ." as " . $db['user'] . "</h4>";
echo "<b>MySQL Error</b>: ", mysql_error();
die();
}
mysql_select_db($db['db']) or die("Could not select database");
fclose($fp);
} else if (!in_array($db['host'], $this->CK)){
// Could not open connection. Lets try again?
$this->CK[$db['host']] = true;
$this->db_query($this->QUERY);
} else {
die('Unable to connect to any database');
}
return $this->LINK_ID;
}
function db_query($query, $debug=false, $die_on_debug=true) {
/* Run the query $query against the current database. if $debug is true, then
* we will just display the query on screen including host info.
* Check for SELECT statments and if SLAVES & RANDOMIZE are set. If so, run
* query against random db host.*/
$this->QUERY = $query;
if (eregi("^select", $query) and (!empty($this->RANDOMIZE)) and (!empty($this->SLAVES)) ) {
// Set the random number
srand ((float) microtime() * 10000000);
// Choose a random Database host
$rand_host = array_rand($this->SLAVES);
$this->LINK_ID = $this->db_connect($this->SLAVES[$rand_host]);
// Now the slave is the MASTER (For display)
$this->MASTER = $this->SLAVES[$rand_host];
} else {
// Use the Master Connection
$this->LINK_ID = $this->db_connect($this->MASTER);
}
if ($debug) {
echo "<pre>" . "LINK " . $this->LINK_ID . " <BR>Query: ". htmlspecialchars($query) . " <BR>HOST: " . $this->MASTER['host'] . "</pre>";
if ($die_on_debug) die;
}
return mysql_query($query, $this->LINK_ID);
}
function db_fetch_array($result) {
/* return next row as an associative array
return FALSE when ther are no more results*/
return mysql_fetch_array($result);
}
function db_fetch_row($result) {
/* return next row as an array
return FALSE when ther are no more results*/
return mysql_fetch_row($result);
}
function db_fetch_object($result) {
/* return next row as an object
return FALSE when ther are no more results*/
return mysql_fetch_object($result);
}
function db_num_rows($result) {
/* return the number of (rows) returned from the SELECT query with
* the query result identifier $result. */
return mysql_num_rows($result);
}
function db_affected_rows() {
/* return the number of rows affected by the last INSERT, UPDATE, or DELETE
* query */
return mysql_affected_rows();
}
function db_insert_id() {
/* if you just INSERTed a new row into a table with an autonumber, call this
* function to give you the ID of the new autonumber value */
return mysql_insert_id();
}
function db_free_result($result) {
/* free up the resources used by the query result identifier $result */
mysql_free_result($result);
}
function db_num_fields($result) {
/* return the number of fields returned from the SELECT query with the
* identifier $result */
return mysql_num_fields($result);
}
function db_field_name($result, $field) {
/* return the name of the field number $field returned from the SELECT query
* with the identifier $result */
return mysql_field_name($result, $field);
}
function db_data_seek($result, $row) {
/* move the database cursor to row $row on the SELECT query with the identifier
* $result */
if (db_num_rows($result)) { return mysql_data_seek($result, $row); }
}
}// END class DB
?>
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