X-Git-Url: https://jasonwoof.com/gitweb/?a=blobdiff_plain;f=db.php;h=d24d8b6f48a839f3481b96ea0518ae2f080ac452;hb=13d85a7f5e140e4983fcbaa22914ed6b16f31a78;hp=6964e9568d8667a4366520de08e232458b23fd95;hpb=70f9d228533a08f8b07aa55eebcf6371aee6cef6;p=wfpl.git

diff --git a/db.php b/db.php
index 6964e95..d24d8b6 100644
--- a/db.php
+++ b/db.php
@@ -64,9 +64,10 @@ function db_connect_now($database = 'auto', $user = 'auto', $pass = 'auto', $hos
 		}
 	}
 
-	$GLOBALS['wfpl_db_handle'] = mysqli_connect($host, $user, $pass);
+	$GLOBALS['wfpl_db_handle'] = @mysqli_connect($host, $user, $pass);
 	if(!$GLOBALS['wfpl_db_handle']) {
-		die('Could not connect to the database: ' . mysqli_error());
+		die('Server error: Database connection failed');
+		# to show username and host: mysqli_connect_error()
 	}
 
 	mysqli_set_charset($GLOBALS['wfpl_db_handle'], $encoding);
@@ -534,3 +535,73 @@ function db_reposition($table, $row_id, $new_pos, $field = 'ord', $pretty = 'sam
 		return $prev_ord + round(($next_ord - $prev_ord) / 2);
 	}
 }
+
+# Call this to upgrade your database (using upgrade functions you define.)
+#
+# You can call this from config.php right after db_connect() to make sure the
+# database is up to date.
+#
+# When you want to update your schema, define a new function named
+# db_upgrade_to_X() where X is the next integer (start at 1).
+#
+# If there are any page views while your upgrade function is running, they will
+# stall until the upgrade function completes. This is often better than running
+# while the databse is in a transitional state, and is way way better than
+# running the upgrade function multiple times concurrently.
+#
+# Efficiency: this function is designed to be lean enough that you'd run it on
+# every page load, so you never forget to upgrade your schema after uploading
+# code changes. If your schema is up to date, this will only execute one
+# database query, and that query loads the persistent data store (used by
+# persistent_get()), so if you use that, you'll need that query to happen
+# anyway (giving this function a zero-query overhead).
+
+function db_upgrade() {
+	if (isset($GLOBALS['wfpl_persistent'])) {
+		$version = persistent_get('wfpl_db_version');
+	} else {
+		# custom version of persistent_init() that creates the table if needed
+		# instead of dying
+		$GLOBALS['wfpl_persistent'] = array();
+		_db_connection_needed();
+		$result = mysqli_query($GLOBALS['wfpl_db_handle'], 'select k,v from wfpl_persistent');
+		if ($result) {
+			while($row = mysqli_fetch_assoc($result)) {
+				$GLOBALS['wfpl_persistent'][$row['k']] = json_decode($row['v'], true);
+			} unset($row);
+			if (isset($GLOBALS['wfpl_persistent']['wfpl_db_version'])) {
+				$version = $GLOBALS['wfpl_persistent']['wfpl_db_version'];
+			} else {
+				$version = -1;
+			}
+		} else {
+			db_send_query('create table if not exists wfpl_persistent (k varchar(30) binary not null default "", v mediumblob, primary key (k)) CHARSET=utf8;');
+			$version = -1;
+		}
+	}
+
+	if ($version === -1) {
+		db_send_query('create table if not exists wfpl_mutexes (id int unique auto_increment, name varchar(30) binary, expires int(11)) CHARSET=utf8;');
+		$version = 0;
+		# don't save version now in case another thread is doing this too
+	}
+	$next = $version + 1;
+	if (function_exists("db_upgrade_to_$next")) {
+		require_once(__DIR__.'/'.'persistent.php');
+		require_once(__DIR__.'/'.'mutex.php');
+		mutex_lock('wfpl_db_upgrade', 20);
+		# check version again, in case another thread upgraded the database
+		# while we waited for a lock just now
+		persistent_invalidate_cache();
+		$version = persistent_get('wfpl_db_version');
+		if ($version === null) {
+			$version = 0;
+		}
+
+		for ($next = $version + 1; function_exists("db_upgrade_to_$next"); ++$next) {
+			call_user_func("db_upgrade_to_$next");
+			persistent_set('wfpl_db_version', $next);
+		}
+		mutex_unlock('wfpl_db_upgrade');
+	}
+}