Use multiple databases.

git-svn-id: http://svn.automattic.com/wordpress-mu/trunk@80 7be80a69-a1ef-0310-a953-fb0f7c49ff36

3 files changed, 126 insertions, 2 deletions

diff --git a/wp-inst/wp-config-sample.php b/wp-inst/wp-config-sample.php
index 6ceb2da..32f9276 100644
--- a/wp-inst/wp-config-sample.php
+++ b/wp-inst/wp-config-sample.php
@@ -16,6 +16,49 @@ $table_prefix  = 'wp_';   // example: 'wp_' or 'b2' or 'mylogin_'
 // to enable German language support.
 define ('WPLANG', '');
 
+define( "WP_USE_MULTIPLE_DB", false );
+$db_list = array( 
+	"write" => array( 
+			array(	"db_name"	=> "WRITE_DB_NAME1",
+				"db_user"	=> "WRITE_DB_USER1",
+				"db_password"	=> "WRITE_DB_PASS1",
+				"db_host"	=> "WRITE_DB_HOST1"
+			)
+		),
+	"read" => array(
+			array(	"db_name"	=> "READ_DB_NAME1",
+				"db_user"	=> "READ_DB_USER1",
+				"db_password"	=> "READ_DB_PASS1",
+				"db_host"	=> "READ_DB_HOST1"
+			),
+			array(	"db_name"	=> "READ_DB_NAME2",
+				"db_user"	=> "READ_DB_USER2",
+				"db_password"	=> "READ_DB_PASS2",
+				"db_host"	=> "READ_DB_HOST2"
+			),
+			array(	"db_name"	=> "READ_DB_NAME3",
+				"db_user"	=> "READ_DB_USER3",
+				"db_password"	=> "READ_DB_PASS3",
+				"db_host"	=> "READ_DB_HOST3"
+			),
+			array(	"db_name"	=> "READ_DB_NAME4",
+				"db_user"	=> "READ_DB_USER4",
+				"db_password"	=> "READ_DB_PASS4",
+				"db_host"	=> "READ_DB_HOST4"
+			),
+			array(	"db_name"	=> "READ_DB_NAME5",
+				"db_user"	=> "READ_DB_USER5",
+				"db_password"	=> "READ_DB_PASS5",
+				"db_host"	=> "READ_DB_HOST5"
+			),
+			array(	"db_name"	=> "READ_DB_NAME6",
+				"db_user"	=> "READ_DB_USER6",
+				"db_password"	=> "READ_DB_PASS6",
+				"db_host"	=> "READ_DB_HOST6"
+			)
+		)
+	);
+
 /* Stop editing */
 
 define('ABSPATH', dirname(__FILE__).'/');
diff --git a/wp-inst/wp-includes/wp-db.php b/wp-inst/wp-includes/wp-db.php
index 73d4be7..765b0c0 100644
--- a/wp-inst/wp-includes/wp-db.php
+++ b/wp-inst/wp-includes/wp-db.php
@@ -53,6 +53,10 @@ class wpdb {
 <p>If you're unsure what these terms mean you should probably contact your host. If you still need help you can always visit the <a href='http://wordpress.org/support/'>WordPress Support Forums</a>.</p>
 ");
 		}
+		$this->db_host		= $dbhost;
+		$this->db_user		= $dbuser;
+		$this->db_password	= $dbpass;
+		$this->db_name		= $dbname;
 
 		$this->select($dbname);
 	}
@@ -124,6 +128,48 @@ class wpdb {
 		$this->last_query = null;
 	}
 
+	function db_connect( $query ) {
+		global $db_list;
+		if( is_array( $db_list ) == false )
+			return true;
+
+		if ( preg_match("/^\\s*(insert|delete|update|replace) /i",$query) ) {
+			$details = $db_list[ 'write' ][ mt_rand( 0, count( $db_list[ 'write' ] ) -1 ) ];
+		} else {
+			$details = $db_list[ 'read' ][ mt_rand( 0, count( $db_list[ 'read' ] ) -1 ) ];
+		}
+
+		if( $this->db_host != $details[ 'db_host' ] || $this->db_user != $details[ 'db_user' ] || $this->db_password != $details[ 'db_password' ] ) {
+			if ($this->dbh) {
+				@mysql_close( $this->dbh );
+			}
+			$this->db_host		= $details[ 'db_host' ];
+			$this->db_user		= $details[ 'db_user' ];
+			$this->db_password	= $details[ 'db_password' ];
+
+			$this->dbh = @mysql_connect( $details[ 'db_host' ], $details[ 'db_user' ], $details[ 'db_password' ] );
+			if (!$this->dbh) {
+				$this->bail("
+<h1>Error establishing a database connection</h1>
+<p>This either means that the username and password information in your <code>wp-config.php</code> file is incorrect or we can't contact the database server at <code>$dbhost</code>. This could mean your host's database server is down.</p>
+<ul>
+	<li>Are you sure you have the correct username and password?</li>
+	<li>Are you sure that you have typed the correct hostname?</li>
+	<li>Are you sure that the database server is running?</li>
+</ul>
+<p>If you're unsure what these terms mean you should probably contact your host. If you still need help you can always visit the <a href='http://wordpress.org/support/'>WordPress Support Forums</a>.</p>
+");
+			}
+			$this->db_name = $details[ 'db_name' ];
+			$this->select( $details[ 'db_name' ] );
+		}
+
+		if( $this->db_name != $details[ 'db_name' ] ) {
+			$this->db_name = $details[ 'db_name' ];
+			$this->select( $details[ 'db_name' ] );
+		}
+	}
+
 	// ==================================================================
 	//	Basic Query	- see docs for more detail
 
@@ -142,6 +188,9 @@ class wpdb {
 		if (SAVEQUERIES)
 			$this->timer_start();
 		
+		if( defined( "WP_USE_MULTIPLE_DB" ) && CONSTANT( "WP_USE_MULTIPLE_DB" ) == true )
+			$this->db_connect( $query );
+
 		$this->result = @mysql_query($query, $this->dbh);
 		++$this->num_queries;
 
@@ -359,4 +408,4 @@ HEAD;
 }
 
 $wpdb = new wpdb(DB_USER, DB_PASSWORD, DB_NAME, DB_HOST);
-?>
\ No newline at end of file
+?>
diff --git a/wp-inst/wp-settings.php b/wp-inst/wp-settings.php
index 5cc3d63..7e51374 100644
--- a/wp-inst/wp-settings.php
+++ b/wp-inst/wp-settings.php
@@ -52,12 +52,38 @@ $domain = $_SERVER['HTTP_HOST'];
 if( substr( $domain, 0, 4 ) == 'www.' )
 	$domain = substr( $domain, 4 );
 
+function is_installed() {
+    global $wpdb, $domain, $base;
+    $check = $wpdb->get_results( "SELECT * FROM $wpdb->site" );
+    if( $check == false ) {
+	$msg = '<strong>Database Tables Missing.</strong><br /> The table <em>' . DB_NAME . '::' . $wpdb->site . '</em> is missing. Delete the .htaccess file and run the installer again!<br />';
+    } else {
+	$msg = '<strong>Could Not Find Blog!</strong><br />';
+	$msg .= "Searched for <em>" . $domain . $base . "</em> in " . DB_NAME . "::" . $wpdb->blogs . " table. Is that right?<br />";
+    }
+    $msg .= "Please check that your database contains the following tables:<ul>
+    <li> $wpdb->blogs </li>
+    <li> $wpdb->users </li>
+    <li> $wpdb->usermeta </li>
+    <li> $wpdb->site </li>
+    <li> $wpdb->sitemeta </li>
+    <li> $wpdb->sitecategories </li>
+    </ul>";
+    $msg .= "If you suspect a problem please report it to <a href='http://mu.wordpress.org/forums/'>support forums</a>!";
+    die( "<h1>Fatal Error</h1> " . $msg );
+}
 $current_blog = $wpdb->get_row("SELECT * FROM $wpdb->blogs WHERE domain = '$domain' AND path = '$base'");
+if( $current_blog == false ) {
+    is_installed();
+}
 $blog_id   = $current_blog->blog_id;
 $is_public = $current_blog->is_public;
 $site_id   = $current_blog->site_id;
 
 $current_site = $wpdb->get_row("SELECT * FROM $wpdb->site WHERE id='$site_id'");
+if( $current_site == false ) {
+    is_installed();
+}
 if( $current_site->domain == $domain && $current_site->path == $base ) {
 	$wpblog = 'main';
 }
@@ -76,7 +102,13 @@ if( $blog_id == false ) {
 	    $blog_id = 1;
 	}
     } else {
-	die( "No Blog by that name on this system." );
+	$check = $wpdb->get_results( "SELECT * FROM $wpdb->site" );
+	if( $check == false ) {
+	    $msg = ': DB Tables Missing';
+	} else {
+	    $msg = '';
+	}
+	die( "No Blog by that name on this system." . $msg );
     }
 }