First cut of AutoBackupModule; only compile-tested so far

1 files changed, 540 insertions, 0 deletions

diff --git a/OpenSim/Region/OptionalModules/World/AutoBackup/AutoBackupModule.cs b/OpenSim/Region/OptionalModules/World/AutoBackup/AutoBackupModule.cs
new file mode 100644
index 0000000..ed21e41
--- /dev/null
+++ b/OpenSim/Region/OptionalModules/World/AutoBackup/AutoBackupModule.cs
@@ -0,0 +1,540 @@
+/*
+ * 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 OpenSimulator 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.IO;
+using System.Timers;
+using System.Diagnostics;
+using System.Reflection;
+using System.Collections.Generic;
+using log4net;
+using Nini;
+using Nini.Config;
+using OpenSim.Framework;
+using OpenSim.Region.Framework.Interfaces;
+
+
+/*
+ * Config Settings Documentation.
+ * EACH REGION in e.g. Regions/Regions.ini can have the following options:
+ * AutoBackup: True/False. Default: False. If True, activate auto backup functionality. 
+ *      This is the only required option for enabling auto-backup; the other options have sane defaults. 
+ *      If False, the auto-backup module becomes a no-op for the region, and all other AutoBackup* settings are ignored.
+ * AutoBackupInterval: Double, non-negative value. Default: 720 (12 hours). 
+ *      The number of minutes between each backup attempt. 
+ *      If a negative or zero value is given, it is equivalent to setting AutoBackup = False.
+ * AutoBackupBusyCheck: True/False. Default: True. 
+ *      If True, we will only take an auto-backup if a set of conditions are met. 
+ *      These conditions are heuristics to try and avoid taking a backup when the sim is busy.
+ * AutoBackupScript: String. Default: not specified (disabled). 
+ *      File path to an executable script or binary to run when an automatic backup is taken.
+ *  The file should really be (Windows) an .exe or .bat, or (Linux/Mac) a shell script or binary.
+ *  Trying to "run" directories, or things with weird file associations on Win32, might cause unexpected results!
+ *      argv[1] of the executed file/script will be the file name of the generated OAR. 
+ *      If the process can't be spawned for some reason (file not found, no execute permission, etc), write a warning to the console.
+ * AutoBackupNaming: string. Default: Time.
+ *      One of three strings (case insensitive):
+ *      "Time": Current timestamp is appended to file name. An existing file will never be overwritten.
+ *  "Sequential": A number is appended to the file name. So if RegionName_x.oar exists, we'll save to RegionName_{x+1}.oar next. An existing file will never be overwritten.
+ *  "Overwrite": Always save to file named "${AutoBackupDir}/RegionName.oar", even if we have to overwrite an existing file.
+ * AutoBackupDir: String. Default: "." (the current directory).
+ *      A directory (absolute or relative) where backups should be saved.
+ * */
+
+namespace OpenSim.Region.OptionalModules.World.AutoBackup
+{
+        
+        public enum NamingType
+        {
+                TIME,
+                SEQUENTIAL,
+                OVERWRITE
+        };
+        
+        public class AutoBackupModule : ISharedRegionModule, IRegionModuleBase
+        {
+                
+                private static readonly ILog m_log = 
+            LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+                
+                //AutoBackupModuleState: Auto-Backup state for one region (scene).
+                public class AutoBackupModuleState
+                {
+                        private readonly IScene m_scene;
+                        private bool m_enabled = false;
+                        private NamingType m_naming = NamingType.TIME;
+                        private Timer m_timer = null;
+                        private bool m_busycheck = true;
+                        private string m_script = null;
+                        private string m_dir = ".";
+                        
+                        public AutoBackupModuleState(IScene scene)
+                        {
+                                m_scene = scene;
+                                if(scene == null)
+                                        throw new NullReferenceException("Required parameter missing for AutoBackupModuleState constructor");
+                        }
+                        
+                        public void SetEnabled(bool b)
+                        {
+                                m_enabled = b;  
+                        }
+                        
+                        public bool GetEnabled()
+                        {
+                                return m_enabled;       
+                        }
+                        
+                        public Timer GetTimer()
+                        {
+                                return m_timer; 
+                        }
+                        
+                        public void SetTimer(Timer t)
+                        {
+                                m_timer = t;    
+                        }
+                        
+                        public bool GetBusyCheck()
+                        {
+                                return m_busycheck;     
+                        }
+                        
+                        public void SetBusyCheck(bool b)
+                        {
+                                m_busycheck = b;        
+                        }
+                        
+                        
+                        public string GetScript()
+                        {
+                                return m_script;        
+                        }
+                        
+                        public void SetScript(string s)
+                        {
+                                m_script = s;   
+                        }
+                        
+                        public string GetBackupDir()
+                        {
+                                return m_dir;   
+                        }
+                        
+                        public void SetBackupDir(string s)
+                        {
+                                m_dir = s;      
+                        }
+                        
+                        public NamingType GetNamingType()
+                        {
+                                return m_naming;
+                        }
+                        
+                        public void SetNamingType(NamingType n)
+                        {
+                                m_naming = n;   
+                        }
+                }
+                
+                //Save memory by setting low initial capacities. Minimizes impact in common cases of all regions using same interval, and instances hosting 1 ~ 4 regions.
+                //Also helps if you don't want AutoBackup at all
+                readonly Dictionary<IScene, AutoBackupModuleState> states = new Dictionary<IScene, AutoBackupModuleState>(4);
+                readonly Dictionary<double, Timer> timers = new Dictionary<double, Timer>(1);
+                readonly Dictionary<Timer, List<IScene>> timerMap = new Dictionary<Timer, List<IScene>>(1);
+                
+                public AutoBackupModule ()
+                {
+                        
+                }
+
+                #region IRegionModuleBase implementation
+                void IRegionModuleBase.Initialise (Nini.Config.IConfigSource source)
+                {
+                        //I have no overall config settings to care about.
+                }
+
+                void IRegionModuleBase.Close ()
+                {
+                        //We don't want any timers firing while the sim's coming down; strange things may happen.
+                        StopAllTimers();
+                }
+
+                void IRegionModuleBase.AddRegion (Framework.Scenes.Scene scene)
+                {
+                        //NO-OP. Wait for the region to be loaded.
+                }
+
+                void IRegionModuleBase.RemoveRegion (Framework.Scenes.Scene scene)
+                {
+                        AutoBackupModuleState abms = states[scene];
+                        Timer timer = abms.GetTimer();
+                        List<IScene> list = timerMap[timer];
+                        list.Remove(scene);
+                        if(list.Count == 0)
+                        {
+                                timerMap.Remove(timer);
+                                timers.Remove(timer.Interval);
+                                timer.Close();
+                        }
+                }
+
+                void IRegionModuleBase.RegionLoaded (Framework.Scenes.Scene scene)
+                {
+                        //This really ought not to happen, but just in case, let's pretend it didn't...
+                        if(scene == null)
+                                return;
+                        
+                        AutoBackupModuleState st = new AutoBackupModuleState(scene);
+                        states.Add(scene, st);
+                        
+                        //Read the config settings and set variables.
+                        IConfig config = scene.Config.Configs[scene.RegionInfo.RegionName];
+                        st.SetEnabled(config.GetBoolean("AutoBackup", false));
+                        if(!st.GetEnabled()) //If you don't want AutoBackup, we stop.
+                                return;
+                        
+                        //Borrow an existing timer if one exists for the same interval; otherwise, make a new one.
+                        double interval = config.GetDouble("AutoBackupInterval", 720);
+                        if(timers.ContainsKey(interval))
+                        {
+                                st.SetTimer(timers[interval]);
+                        }
+                        else
+                        {
+                                st.SetTimer(new Timer(interval));
+                                timers.Add(interval, st.GetTimer());
+                                st.GetTimer().Elapsed += HandleElapsed;
+                        }
+                        
+                        //Add the current region to the list of regions tied to this timer.
+                        if(timerMap.ContainsKey(st.GetTimer()))
+                        {
+                                timerMap[st.GetTimer()].Add(scene);
+                        }
+                        else
+                        {
+                                List<IScene> scns = new List<IScene>(1);
+                                timerMap.Add(st.GetTimer(), scns);
+                        }
+                        
+                        st.SetBusyCheck(config.GetBoolean("AutoBackupBusyCheck", true));
+                        
+                        //Set file naming algorithm
+                        string namingtype = config.GetString("AutoBackupNaming", "Time");
+                        if(namingtype.Equals("Time", StringComparison.CurrentCultureIgnoreCase))
+                        {
+                                st.SetNamingType(NamingType.TIME);
+                        }
+                        else if(namingtype.Equals("Sequential", StringComparison.CurrentCultureIgnoreCase))
+                        {
+                                st.SetNamingType(NamingType.SEQUENTIAL);        
+                        }
+                        else if(namingtype.Equals("Overwrite", StringComparison.CurrentCultureIgnoreCase))
+                        {
+                                st.SetNamingType(NamingType.OVERWRITE); 
+                        }
+                        else
+                        {
+                                m_log.Warn("Unknown naming type specified for region " + scene.RegionInfo.RegionName + ": " + namingtype);
+                                st.SetNamingType(NamingType.TIME);
+                        }
+                        
+                        st.SetScript(config.GetString("AutoBackupScript", null));
+                        st.SetBackupDir(config.GetString("AutoBackupDir", "."));
+                        
+                        //Let's give the user *one* convenience and auto-mkdir
+                        if(st.GetBackupDir() != ".")
+                        {
+                                try
+                                {
+                                        DirectoryInfo dirinfo = new DirectoryInfo(st.GetBackupDir());
+                                        if(!dirinfo.Exists)
+                                        {
+                                                dirinfo.Create();       
+                                        }
+                                }
+                                catch(Exception e)
+                                {
+                                        m_log.Warn("BAD NEWS. You won't be able to save backups to directory " + st.GetBackupDir() +
+                                                   " because it doesn't exist or there's a permissions issue with it. Here's the exception.", e);
+                                }
+                        }
+                }
+
+                void HandleElapsed (object sender, ElapsedEventArgs e)
+                {
+                        bool heuristicsRun = false;
+                        bool heuristicsPassed = false;
+                        foreach(IScene scene in timerMap[(Timer)sender])
+                        {
+                                AutoBackupModuleState state = states[scene];
+                                bool heuristics = state.GetBusyCheck();
+                                
+                                //Fast path: heuristics are on; already ran em; and sim is fine; OR, no heuristics for the region.
+                                if((heuristics && heuristicsRun && heuristicsPassed)
+                                   || !heuristics)
+                                {
+                                        IRegionArchiverModule iram = scene.RequestModuleInterface<IRegionArchiverModule>();
+                                        string savePath = BuildOarPath(scene.RegionInfo.RegionName, state.GetBackupDir(), state.GetNamingType());
+                                        if(savePath == null)
+                                        {
+                                                m_log.Warn("savePath is null in HandleElapsed");
+                                                continue;
+                                        }
+                                        iram.ArchiveRegion(savePath, null);
+                                        ExecuteScript(state.GetScript(), savePath);
+                                }
+                                //Heuristics are on; ran but we're too busy -- keep going. Maybe another region will have heuristics off!
+                                else if(heuristics && heuristicsRun && !heuristicsPassed)
+                                {
+                                        continue;
+                                }
+                                //Logical Deduction: heuristics are on but haven't been run
+                                else
+                                {
+                                        heuristicsPassed = RunHeuristics();
+                                        heuristicsRun = true;
+                                        if(!heuristicsPassed)
+                                                continue;
+                                }
+                        }
+                }
+
+                string IRegionModuleBase.Name {
+                        get {
+                                return "AutoBackupModule";
+                        }
+                }
+
+                Type IRegionModuleBase.ReplaceableInterface {
+                        get {
+                                return null;
+                        }
+                }
+                                             
+                #endregion
+                #region ISharedRegionModule implementation
+                void ISharedRegionModule.PostInitialise ()
+                {
+                        //I don't care right now.
+                }
+                
+                #endregion
+                
+                //Is this even needed?
+                public bool IsSharedModule
+        {
+            get { return true; }
+        }
+                
+                private string BuildOarPath(string regionName, string baseDir, NamingType naming)
+                {
+                        FileInfo path = null;
+                        switch(naming)
+                        {
+                        case NamingType.OVERWRITE:
+                                path = new FileInfo(baseDir + Path.DirectorySeparatorChar + regionName);
+                                return path.FullName;
+                        case NamingType.TIME:
+                                path = new FileInfo(baseDir + Path.DirectorySeparatorChar + regionName + GetTimeString() + ".oar");
+                                return path.FullName;
+                        case NamingType.SEQUENTIAL:
+                                path = new FileInfo(baseDir + Path.DirectorySeparatorChar + regionName + "_" + GetNextFile(baseDir, regionName) + ".oar");
+                                return path.FullName;
+                        default:
+                                m_log.Warn("VERY BAD: Unhandled case element " + naming.ToString());
+                                break;
+                        }
+                        
+                        return path.FullName;
+                }
+                
+                //Welcome to the TIME STRING. 4 CORNER INTEGERS, CUBES 4 QUAD MEMORY -- No 1 Integer God.
+                //(Terrible reference to <timecube.com>)
+                //This format may turn out to be too unwieldy to keep...
+                //Besides, that's what ctimes are for. But then how do I name each file uniquely without using a GUID?
+                //Sequential numbers, right? Ugh. Almost makes TOO much sense.
+                private string GetTimeString()
+                {
+                        StringWriter sw = new StringWriter();
+                        sw.Write("_");
+                        DateTime now = DateTime.Now;
+                        sw.Write(now.Year);
+                        sw.Write("y_");
+                        sw.Write(now.Month);
+                        sw.Write("M_");
+                        sw.Write(now.Day);
+                        sw.Write("d_");
+                        sw.Write(now.Hour);
+                        sw.Write("h_");
+                        sw.Write(now.Minute);
+                        sw.Write("m_");
+                        sw.Write(now.Second);
+                        sw.Write("s");
+                        sw.Flush();
+                        string output = sw.ToString();
+                        sw.Close();
+                        return output;
+                }
+                
+                //Get the next logical file name
+                //I really shouldn't put fields here, but for now.... ;)
+                private string m_dirName = null;
+                private string m_regionName = null;
+                private string GetNextFile(string dirName, string regionName)
+                {
+                        FileInfo uniqueFile = null;
+                        m_dirName = dirName;
+                        m_regionName = regionName;
+                        long biggestExistingFile = HalfIntervalMaximize(1, FileExistsTest);
+                        biggestExistingFile++; //We don't want to overwrite the biggest existing file; we want to write to the NEXT biggest.
+                        
+                        uniqueFile = new FileInfo(m_dirName + Path.DirectorySeparatorChar + m_regionName + "_" + biggestExistingFile + ".oar");
+                        if(uniqueFile.Exists)
+                        {
+                                //Congratulations, your strange deletion patterns fooled my half-interval search into picking an existing file!
+                                //Now you get to pay the performance cost :)
+                                uniqueFile = UniqueFileSearchLinear(biggestExistingFile);
+                        }
+                        
+                        return uniqueFile.FullName;
+                }
+                                        
+                private bool RunHeuristics()
+                {
+                        return true;
+                }
+                
+                private void ExecuteScript(string scriptName, string savePath)
+                {
+                        //Fast path out
+                        if(scriptName == null || scriptName.Length <= 0)
+                                return;
+                        
+                        try
+                        {
+                                FileInfo fi = new FileInfo(scriptName);
+                                if(fi.Exists)
+                                {
+                                        ProcessStartInfo psi = new ProcessStartInfo(scriptName);
+                                        psi.Arguments = savePath;
+                                        psi.CreateNoWindow = true;
+                                        Process proc = Process.Start(psi);
+                                        proc.ErrorDataReceived += HandleProcErrorDataReceived;
+                                }
+                        }
+                        catch(Exception e)
+                        {
+                                m_log.Warn("Exception encountered when trying to run script for oar backup " + savePath, e);
+                        }
+                }
+
+                void HandleProcErrorDataReceived (object sender, DataReceivedEventArgs e)
+                {
+                        m_log.Warn("ExecuteScript hook " + ((Process)sender).ProcessName + " is yacking on stderr: " + e.Data);
+                }
+                
+                private void StopAllTimers()
+                {
+                        foreach(Timer t in timerMap.Keys)
+                        {
+                                t.Close();      
+                        }
+                }
+                
+                /* Find the largest value for which the predicate returns true.
+                 * We use a bisection algorithm (half interval) to make the algorithm scalable.
+                 * The worst-case complexity is about O(log(n)^2) in practice.
+                 * Only for extremely small values (under 10) do you notice it taking more iterations than a linear search.
+                 * The number of predicate invocations only hits a few hundred when the maximized value
+                 *     is in the tens of millions, so prepare for the predicate to be invoked between 10 and 100 times.
+                 * And of course it is fantastic with powers of 2, which are densely packed in values under 100 anyway.
+                 * The Predicate<long> parameter must be a function that accepts a long and returns a bool.
+                 * */
+                public long HalfIntervalMaximize(long start, Predicate<long> pred)
+                {
+                        long prev = start, curr = start, biggest = 0;
+                        
+                        if(start < 0)
+                                throw new IndexOutOfRangeException("Start value for HalfIntervalMaximize must be non-negative");
+                        
+                        do
+                        {
+                                if(pred(curr))
+                                {
+                                        if(curr > biggest)
+                                        {
+                                                biggest = curr;
+                                        }
+                                        prev = curr;
+                                        if(curr == 0)
+                                        {
+                                                //Special case because 0 * 2 = 0 :)
+                                                curr = 1;
+                                        }
+                                        else
+                                        {
+                                                //Look deeper
+                                                curr *= 2;
+                                        }
+                                }
+                                else
+                                {
+                                        // We went too far, back off halfway
+                                        curr = (curr + prev) / 2;
+                                }
+                        }
+                        while(curr - prev > 0);
+                        
+                        return biggest;
+                }
+                
+                public bool FileExistsTest(long num)
+                {
+                        FileInfo test = new FileInfo(m_dirName + Path.DirectorySeparatorChar + m_regionName + "_" + num + ".oar");
+                        return test.Exists;
+                }
+                
+                
+                //Very slow, hence why we try the HalfIntervalMaximize first!
+                public FileInfo UniqueFileSearchLinear(long start)
+                {
+                        long l = start;
+                        FileInfo retval = null;
+                        do
+                        {
+                                retval = new FileInfo(m_dirName + Path.DirectorySeparatorChar + m_regionName + "_" + (l++) + ".oar");
+                        }
+                        while(retval.Exists);
+                        
+                        return retval;
+                }
+}
+        
+}
+