/* * Copyright (c) Contributors, http://opensimulator.org/ * See CONTRIBUTORS.TXT for a full list of copyright holders. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of the OpenSim Project nor the * names of its contributors may be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ using System; using System.Collections.Generic; using System.Data; using System.Data.Common; using System.IO; using System.Reflection; using System.Text.RegularExpressions; using log4net; namespace OpenSim.Data { /// <summary> /// /// The Migration theory is based on the ruby on rails concept. /// Each database driver is going to be allowed to have files in /// Resources that specify the database migrations. They will be /// of the form: /// /// 001_Users.sql /// 002_Users.sql /// 003_Users.sql /// 001_Prims.sql /// 002_Prims.sql /// ...etc... /// /// When a database driver starts up, it specifies a resource that /// needs to be brought up to the current revision. For instance: /// /// Migration um = new Migration(Assembly, DbConnection, "Users"); /// um.Upgrade(); /// /// This works out which version Users is at, and applies all the /// revisions past it to it. If there is no users table, all /// revisions are applied in order. Consider each future /// migration to be an incremental roll forward of the tables in /// question. /// /// Assembly must be specifically passed in because otherwise you /// get the assembly that Migration.cs is part of, and what you /// really want is the assembly of your database class. /// /// </summary> public class Migration { private static readonly log4net.ILog m_log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType); private string _type; private DbConnection _conn; private string _subtype; private Assembly _assem; private Regex _match; private static readonly string _migrations_create = "create table migrations(name varchar(100), version int)"; private static readonly string _migrations_init = "insert into migrations values('migrations', 1)"; private static readonly string _migrations_find = "select version from migrations where name='migrations'"; public Migration(DbConnection conn, Assembly assem, string type) { _type = type; _conn = conn; _assem = assem; _match = new Regex(@"\.(\d\d\d)_" + _type + @"\.sql"); Initialize(); } public Migration(DbConnection conn, Assembly assem, string subtype, string type) { _type = type; _conn = conn; _assem = assem; _match = new Regex(subtype + @"\.(\d\d\d)_" + _type + @"\.sql"); Initialize(); } private void Initialize() { // clever, eh, we figure out which migrations version we are int migration_version = FindVersion("migrations"); if (migration_version > 0) return; // If not, create the migration tables DbCommand cmd = _conn.CreateCommand(); cmd.CommandText = _migrations_create; cmd.ExecuteNonQuery(); InsertVersion("migrations", 1); } public void Update() { int version = 0; version = FindVersion(_type); SortedList<int, string> migrations = GetMigrationsAfter(version); DbCommand cmd = _conn.CreateCommand(); foreach (KeyValuePair<int, string> kvp in migrations) { int newversion = kvp.Key; cmd.CommandText = kvp.Value; cmd.ExecuteNonQuery(); if (version == 0) { InsertVersion(_type, newversion); } else { UpdateVersion(_type, newversion); } version = newversion; } } private int MaxVersion() { int max = 0; string[] names = _assem.GetManifestResourceNames(); foreach (string s in names) { Match m = _match.Match(s); if (m.Success) { int MigrationVersion = int.Parse(m.Groups[1].ToString()); if (MigrationVersion > max) max = MigrationVersion; } } return max; } public int Version { get { return FindVersion(_type); } set { if (Version < 1) { InsertVersion(_type, value); } else { UpdateVersion(_type, value); } } } private int FindVersion(string type) { int version = 0; DbCommand cmd = _conn.CreateCommand(); try { cmd.CommandText = "select version from migrations where name='" + type + "' limit 1"; using (IDataReader reader = cmd.ExecuteReader()) { if (reader.Read()) { version = Convert.ToInt32(reader["version"]); } reader.Close(); } } catch { // Something went wrong, so we're version 0 } return version; } private void InsertVersion(string type, int version) { DbCommand cmd = _conn.CreateCommand(); cmd.CommandText = "insert into migrations(name, version) values('" + type + "', " + version + ")"; m_log.InfoFormat("Creating {0} at version {1}", type, version); cmd.ExecuteNonQuery(); } private void UpdateVersion(string type, int version) { DbCommand cmd = _conn.CreateCommand(); cmd.CommandText = "update migrations set version=" + version + " where name='" + type + "'"; m_log.InfoFormat("Updating {0} to version {1}", type, version); cmd.ExecuteNonQuery(); } private SortedList<int, string> GetAllMigrations() { return GetMigrationsAfter(0); } private SortedList<int, string> GetMigrationsAfter(int after) { string[] names = _assem.GetManifestResourceNames(); SortedList<int, string> migrations = new SortedList<int, string>(); foreach (string s in names) { Match m = _match.Match(s); if (m.Success) { m_log.Info("MIGRATION: Match: " + m.Groups[1].ToString()); int version = int.Parse(m.Groups[1].ToString()); if (version > after) { using (Stream resource = _assem.GetManifestResourceStream(s)) { using (StreamReader resourceReader = new StreamReader(resource)) { string resourceString = resourceReader.ReadToEnd(); migrations.Add(version, resourceString); } } } } } // TODO: once this is working, get rid of this if (migrations.Count < 1) { m_log.InfoFormat("Resource '{0}' was not found", _type); } return migrations; } } }