aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/OpenSim/Region/OptionalModules/World/AutoBackup/AutoBackupModule.cs
blob: d40caebbee43fa78990f4a90eb2df69ed1f67ab5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
/*
 * 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.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Reflection;
using System.Timers;
using System.Text.RegularExpressions;
using log4net;
using Nini.Config;
using OpenSim.Framework;
using OpenSim.Region.Framework.Interfaces;
using OpenSim.Region.Framework.Scenes;

namespace OpenSim.Region.OptionalModules.World.AutoBackup
{
    /// <summary>
    /// Choose between ways of naming the backup files that are generated.
    /// </summary>
    /// <remarks>Time: OARs are named by a timestamp.
    /// Sequential: OARs are named by counting (Region_1.oar, Region_2.oar, etc.)
    /// Overwrite: Only one file per region is created; it's overwritten each time a backup is made.</remarks>
    public enum NamingType
    {
        Time,
        Sequential,
        Overwrite
    }

    ///<summary>
    /// AutoBackupModule: save OAR region backups to disk periodically
    /// </summary>
    /// <remarks>
    /// Config Settings Documentation.
    /// Each configuration setting can be specified in two places: OpenSim.ini or Regions.ini.
	/// If specified in Regions.ini, the settings should be within the region's section name.
	/// If specified in OpenSim.ini, the settings should be within the [AutoBackupModule] section.
    /// Region-specific settings take precedence.
    /// 
    /// AutoBackupModuleEnabled: True/False. Default: False. If True, use the auto backup module. This setting does not support per-region basis.
    ///     All other settings under [AutoBackupModule] are ignored if AutoBackupModuleEnabled is false, even per-region settings!
    /// 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 for a particular region, the auto-backup module becomes a no-op for the region, and all other AutoBackup* settings are ignored.
    /// 	If False globally (the default), only regions that specifically override it in Regions.ini will get AutoBackup functionality.
    /// 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.
    /// AutoBackupDilationThreshold: float. Default: 0.5. Lower bound on time dilation required for BusyCheck heuristics to pass.
    ///  If the time dilation is below this value, don't take a backup right now.
    /// AutoBackupAgentThreshold: int. Default: 10. Upper bound on # of agents in region required for BusyCheck heuristics to pass.
    ///  If the number of agents is greater than this value, don't take a backup right now
    /// 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.
    /// </remarks>
    public class AutoBackupModule : ISharedRegionModule
    {
        private static readonly ILog m_log =
            LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
        private readonly Dictionary<Guid, IScene> m_pendingSaves = new Dictionary<Guid, IScene>(1);
        private readonly AutoBackupModuleState m_defaultState = new AutoBackupModuleState();
        private readonly Dictionary<IScene, AutoBackupModuleState> m_states =
            new Dictionary<IScene, AutoBackupModuleState>(1);
        private readonly Dictionary<Timer, List<IScene>> m_timerMap =
            new Dictionary<Timer, List<IScene>>(1);
        private readonly Dictionary<double, Timer> m_timers = new Dictionary<double, Timer>(1);

        private delegate T DefaultGetter<T>(string settingName, T defaultValue);
        private bool m_enabled;

        /// <summary>
        /// Whether the shared module should be enabled at all. NOT the same as m_Enabled in AutoBackupModuleState!
        /// </summary>
        private bool m_closed;

        private IConfigSource m_configSource;

        /// <summary>
        /// Required by framework.
        /// </summary>
        public bool IsSharedModule
        {
            get { return true; }
        }

        #region ISharedRegionModule Members

        /// <summary>
        /// Identifies the module to the system.
        /// </summary>
        string IRegionModuleBase.Name
        {
            get { return "AutoBackupModule"; }
        }

        /// <summary>
        /// We don't implement an interface, this is a single-use module.
        /// </summary>
        Type IRegionModuleBase.ReplaceableInterface
        {
            get { return null; }
        }

        /// <summary>
        /// Called once in the lifetime of the module at startup.
        /// </summary>
        /// <param name="source">The input config source for OpenSim.ini.</param>
        void IRegionModuleBase.Initialise(IConfigSource source)
        {
            // Determine if we have been enabled at all in OpenSim.ini -- this is part and parcel of being an optional module
            this.m_configSource = source;
            IConfig moduleConfig = source.Configs["AutoBackupModule"];
            if (moduleConfig == null)
            {
                this.m_enabled = false;
                return;
            }
            else
            {
                this.m_enabled = moduleConfig.GetBoolean("AutoBackupModuleEnabled", false);
                if (this.m_enabled)
                {
                    m_log.Info("[AUTO BACKUP]: AutoBackupModule enabled");
                }
                else
                {
                    return;
                }
            }

            Timer defTimer = new Timer(43200000);
            this.m_defaultState.Timer = defTimer;
            this.m_timers.Add(43200000, defTimer);
            defTimer.Elapsed += this.HandleElapsed;
            defTimer.AutoReset = true;
            defTimer.Start();

            AutoBackupModuleState abms = this.ParseConfig(null, true);
            m_log.Debug("[AUTO BACKUP]: Here is the default config:");
            m_log.Debug(abms.ToString());
        }

        /// <summary>
        /// Called once at de-init (sim shutting down).
        /// </summary>
        void IRegionModuleBase.Close()
        {
            if (!this.m_enabled)
            {
                return;
            }

            // We don't want any timers firing while the sim's coming down; strange things may happen.
            this.StopAllTimers();
        }

        /// <summary>
        /// Currently a no-op for AutoBackup because we have to wait for region to be fully loaded.
        /// </summary>
        /// <param name="scene"></param>
        void IRegionModuleBase.AddRegion(Scene scene)
        {
        }

        /// <summary>
        /// Here we just clean up some resources and stop the OAR backup (if any) for the given scene.
        /// </summary>
        /// <param name="scene">The scene (region) to stop performing AutoBackup on.</param>
        void IRegionModuleBase.RemoveRegion(Scene scene)
        {
            if (!this.m_enabled)
            {
                return;
            }

            if (this.m_states.ContainsKey(scene))
            {
                AutoBackupModuleState abms = this.m_states[scene];

                // Remove this scene out of the timer map list
                Timer timer = abms.Timer;
                List<IScene> list = this.m_timerMap[timer];
                list.Remove(scene);

                // Shut down the timer if this was the last scene for the timer
                if (list.Count == 0)
                {
                    this.m_timerMap.Remove(timer);
                    this.m_timers.Remove(timer.Interval);
                    timer.Close();
                }
                this.m_states.Remove(scene);
            }
        }

        /// <summary>
        /// Most interesting/complex code paths in AutoBackup begin here.
        /// We read lots of Nini config, maybe set a timer, add members to state tracking Dictionaries, etc.
        /// </summary>
        /// <param name="scene">The scene to (possibly) perform AutoBackup on.</param>
        void IRegionModuleBase.RegionLoaded(Scene scene)
        {
            if (!this.m_enabled)
            {
                return;
            }

            // This really ought not to happen, but just in case, let's pretend it didn't...
            if (scene == null)
            {
                return;
            }

            AutoBackupModuleState abms = this.ParseConfig(scene, false);
            m_log.Debug("[AUTO BACKUP]: Config for " + scene.RegionInfo.RegionName);
            m_log.Debug((abms == null ? "DEFAULT" : abms.ToString()));
        }

        /// <summary>
        /// Currently a no-op.
        /// </summary>
        void ISharedRegionModule.PostInitialise()
        {
        }

        #endregion

        /// <summary>
        /// Set up internal state for a given scene. Fairly complex code.
        /// When this method returns, we've started auto-backup timers, put members in Dictionaries, and created a State object for this scene.
        /// </summary>
        /// <param name="scene">The scene to look at.</param>
        /// <param name="parseDefault">Whether this call is intended to figure out what we consider the "default" config (applied to all regions unless overridden by per-region settings).</param>
        /// <returns>An AutoBackupModuleState contains most information you should need to know relevant to auto-backup, as applicable to a single region.</returns>
        private AutoBackupModuleState ParseConfig(IScene scene, bool parseDefault)
        {
            string sRegionName;
            string sRegionLabel;
            string prepend;
            AutoBackupModuleState state;

            if (parseDefault)
            {
                sRegionName = null;
                sRegionLabel = "DEFAULT";
                prepend = "";
                state = this.m_defaultState;
            }
            else
            {
                sRegionName = scene.RegionInfo.RegionName;
                sRegionLabel = sRegionName;
                prepend = sRegionName + ".";
                state = null;
            }

            // Read the config settings and set variables.
            IConfig regionConfig = (scene != null ? scene.Config.Configs[sRegionName] : null);
            IConfig config = this.m_configSource.Configs["AutoBackupModule"];
            if (config == null)
            {
                // defaultState would be disabled too if the section doesn't exist.
                state = this.m_defaultState;
                return state;
            }

            bool tmpEnabled = ResolveBoolean("AutoBackup", this.m_defaultState.Enabled, config, regionConfig);
            if (state == null && tmpEnabled != this.m_defaultState.Enabled)
                //Varies from default state
            {
                state = new AutoBackupModuleState();
            }

            if (state != null)
            {
                state.Enabled = tmpEnabled;
            }

            // If you don't want AutoBackup, we stop.
            if ((state == null && !this.m_defaultState.Enabled) || (state != null && !state.Enabled))
            {
                return state;
            }
            else
            {
                m_log.Info("[AUTO BACKUP]: Region " + sRegionLabel + " is AutoBackup ENABLED.");
            }

            // Borrow an existing timer if one exists for the same interval; otherwise, make a new one.
            double interval =
                this.ResolveDouble("AutoBackupInterval", this.m_defaultState.IntervalMinutes,
                 config, regionConfig) * 60000.0;
            if (state == null && interval != this.m_defaultState.IntervalMinutes*60000.0)
            {
                state = new AutoBackupModuleState();
            }

            if (this.m_timers.ContainsKey(interval))
            {
                if (state != null)
                {
                    state.Timer = this.m_timers[interval];
                }
                m_log.Debug("[AUTO BACKUP]: Reusing timer for " + interval + " msec for region " +
                            sRegionLabel);
            }
            else
            {
                // 0 or negative interval == do nothing.
                if (interval <= 0.0 && state != null)
                {
                    state.Enabled = false;
                    return state;
                }
                if (state == null)
                {
                    state = new AutoBackupModuleState();
                }
                Timer tim = new Timer(interval);
                state.Timer = tim;
                //Milliseconds -> minutes
                this.m_timers.Add(interval, tim);
                tim.Elapsed += this.HandleElapsed;
                tim.AutoReset = true;
                tim.Start();
            }

            // Add the current region to the list of regions tied to this timer.
            if (scene != null)
            {
                if (state != null)
                {
                    if (this.m_timerMap.ContainsKey(state.Timer))
                    {
                        this.m_timerMap[state.Timer].Add(scene);
                    }
                    else
                    {
                        List<IScene> scns = new List<IScene>(1);
                        scns.Add(scene);
                        this.m_timerMap.Add(state.Timer, scns);
                    }
                }
                else
                {
                    if (this.m_timerMap.ContainsKey(this.m_defaultState.Timer))
                    {
                        this.m_timerMap[this.m_defaultState.Timer].Add(scene);
                    }
                    else
                    {
                        List<IScene> scns = new List<IScene>(1);
                        scns.Add(scene);
                        this.m_timerMap.Add(this.m_defaultState.Timer, scns);
                    }
                }
            }

            bool tmpBusyCheck = ResolveBoolean("AutoBackupBusyCheck",
                                                  this.m_defaultState.BusyCheck, config, regionConfig);
            if (state == null && tmpBusyCheck != this.m_defaultState.BusyCheck)
            {
                state = new AutoBackupModuleState();
            }

            if (state != null)
            {
                state.BusyCheck = tmpBusyCheck;
            }

            // Set file naming algorithm
            string stmpNamingType = ResolveString("AutoBackupNaming",
                                                     this.m_defaultState.NamingType.ToString(), config, regionConfig);
            NamingType tmpNamingType;
            if (stmpNamingType.Equals("Time", StringComparison.CurrentCultureIgnoreCase))
            {
                tmpNamingType = NamingType.Time;
            }
            else if (stmpNamingType.Equals("Sequential", StringComparison.CurrentCultureIgnoreCase))
            {
                tmpNamingType = NamingType.Sequential;
            }
            else if (stmpNamingType.Equals("Overwrite", StringComparison.CurrentCultureIgnoreCase))
            {
                tmpNamingType = NamingType.Overwrite;
            }
            else
            {
                m_log.Warn("Unknown naming type specified for region " + sRegionLabel + ": " +
                           stmpNamingType);
                tmpNamingType = NamingType.Time;
            }

            if (state == null && tmpNamingType != this.m_defaultState.NamingType)
            {
                state = new AutoBackupModuleState();
            }

            if (state != null)
            {
                state.NamingType = tmpNamingType;
            }

            string tmpScript = ResolveString("AutoBackupScript",
                                                this.m_defaultState.Script, config, regionConfig);
            if (state == null && tmpScript != this.m_defaultState.Script)
            {
                state = new AutoBackupModuleState();
            }

            if (state != null)
            {
                state.Script = tmpScript;
            }

            string tmpBackupDir = ResolveString("AutoBackupDir", ".", config, regionConfig);
            if (state == null && tmpBackupDir != this.m_defaultState.BackupDir)
            {
                state = new AutoBackupModuleState();
            }

            if (state != null)
            {
                state.BackupDir = tmpBackupDir;
                // Let's give the user some convenience and auto-mkdir
                if (state.BackupDir != ".")
                {
                    try
                    {
                        DirectoryInfo dirinfo = new DirectoryInfo(state.BackupDir);
                        if (!dirinfo.Exists)
                        {
                            dirinfo.Create();
                        }
                    }
                    catch (Exception e)
                    {
                        m_log.Warn(
                            "BAD NEWS. You won't be able to save backups to directory " +
                            state.BackupDir +
                            " because it doesn't exist or there's a permissions issue with it. Here's the exception.",
                            e);
                    }
                }
            }

            return state;
        }

        /// <summary>
        /// Helper function for ParseConfig.
        /// </summary>
        /// <param name="settingName"></param>
        /// <param name="defaultValue"></param>
        /// <param name="global"></param>
        /// <param name="local"></param>
        /// <returns></returns>
        private bool ResolveBoolean(string settingName, bool defaultValue, IConfig global, IConfig local)
        {
            if(local != null)
            {
                return local.GetBoolean(settingName, global.GetBoolean(settingName, defaultValue));
            }
            else
            {
                return global.GetBoolean(settingName, defaultValue);
            }
        }

        /// <summary>
        /// Helper function for ParseConfig.
        /// </summary>
        /// <param name="settingName"></param>
        /// <param name="defaultValue"></param>
        /// <param name="global"></param>
        /// <param name="local"></param>
        /// <returns></returns>
        private double ResolveDouble(string settingName, double defaultValue, IConfig global, IConfig local)
        {
            if (local != null)
            {
                return local.GetDouble(settingName, global.GetDouble(settingName, defaultValue));
            }
            else
            {
                return global.GetDouble(settingName, defaultValue);
            }
        }

        /// <summary>
        /// Helper function for ParseConfig.
        /// </summary>
        /// <param name="settingName"></param>
        /// <param name="defaultValue"></param>
        /// <param name="global"></param>
        /// <param name="local"></param>
        /// <returns></returns>
        private int ResolveInt(string settingName, int defaultValue, IConfig global, IConfig local)
        {
            if (local != null)
            {
                return local.GetInt(settingName, global.GetInt(settingName, defaultValue));
            }
            else
            {
                return global.GetInt(settingName, defaultValue);
            }
        }

        /// <summary>
        /// Helper function for ParseConfig.
        /// </summary>
        /// <param name="settingName"></param>
        /// <param name="defaultValue"></param>
        /// <param name="global"></param>
        /// <param name="local"></param>
        /// <returns></returns>
        private string ResolveString(string settingName, string defaultValue, IConfig global, IConfig local)
        {
            if (local != null)
            {
                return local.GetString(settingName, global.GetString(settingName, defaultValue));
            }
            else
            {
                return global.GetString(settingName, defaultValue);
            }
        }

        /// <summary>
        /// Called when any auto-backup timer expires. This starts the code path for actually performing a backup.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void HandleElapsed(object sender, ElapsedEventArgs e)
        {
            // TODO: heuristic thresholds are per-region, so we should probably run heuristics once per region
            // XXX: Running heuristics once per region could add undue performance penalty for something that's supposed to
            // check whether the region is too busy! Especially on sims with LOTS of regions.
            // Alternative: make heuristics thresholds global to the module rather than per-region. Less flexible,
            //  but would allow us to be semantically correct while being easier on perf.
            // Alternative 2: Run heuristics once per unique set of heuristics threshold parameters! Ay yi yi...
            // Alternative 3: Don't support per-region heuristics at all; just accept them as a global only parameter.
            // Since this is pretty experimental, I haven't decided which alternative makes the most sense.
            if (this.m_closed)
            {
                return;
            }
            bool heuristicsRun = false;
            bool heuristicsPassed = false;
            if (!this.m_timerMap.ContainsKey((Timer) sender))
            {
                m_log.Debug("Code-up error: timerMap doesn't contain timer " + sender);
            }

            List<IScene> tmap = this.m_timerMap[(Timer) sender];
            if (tmap != null && tmap.Count > 0)
            {
                foreach (IScene scene in tmap)
                {
                    AutoBackupModuleState state = this.m_states[scene];
                    bool heuristics = state.BusyCheck;

                    // Fast path: heuristics are on; already ran em; and sim is fine; OR, no heuristics for the region.
                    if ((heuristics && heuristicsRun && heuristicsPassed) || !heuristics)
                    {
                        this.DoRegionBackup(scene);
                        // Heuristics are on; ran but we're too busy -- keep going. Maybe another region will have heuristics off!
                    }
                    else if (heuristicsRun)
                    {
                        m_log.Info("[AUTO BACKUP]: Heuristics: too busy to backup " +
                                   scene.RegionInfo.RegionName + " right now.");
                        continue;
                        // Logical Deduction: heuristics are on but haven't been run
                    }
                    else
                    {
                        heuristicsPassed = this.RunHeuristics(scene);
                        heuristicsRun = true;
                        if (!heuristicsPassed)
                        {
                            m_log.Info("[AUTO BACKUP]: Heuristics: too busy to backup " +
                                       scene.RegionInfo.RegionName + " right now.");
                            continue;
                        }
                        this.DoRegionBackup(scene);
                    }
                }
            }
        }

        /// <summary>
        /// Save an OAR, register for the callback for when it's done, then call the AutoBackupScript (if applicable).
        /// </summary>
        /// <param name="scene"></param>
        private void DoRegionBackup(IScene scene)
        {
            if (scene.RegionStatus != RegionStatus.Up)
            {
                // We won't backup a region that isn't operating normally.
                m_log.Warn("[AUTO BACKUP]: Not backing up region " + scene.RegionInfo.RegionName +
                           " because its status is " + scene.RegionStatus);
                return;
            }

            AutoBackupModuleState state = this.m_states[scene];
            IRegionArchiverModule iram = scene.RequestModuleInterface<IRegionArchiverModule>();
            string savePath = BuildOarPath(scene.RegionInfo.RegionName,
                                                state.BackupDir,
                                                state.NamingType);
            if (savePath == null)
            {
                m_log.Warn("[AUTO BACKUP]: savePath is null in HandleElapsed");
                return;
            }
            Guid guid = Guid.NewGuid();
            m_pendingSaves.Add(guid, scene);
            state.LiveRequests.Add(guid, savePath);
            ((Scene) scene).EventManager.OnOarFileSaved += new EventManager.OarFileSaved(EventManager_OnOarFileSaved);
            iram.ArchiveRegion(savePath, guid, null);
        }

        /// <summary>
        /// Called by the Event Manager when the OnOarFileSaved event is fired.
        /// </summary>
        /// <param name="guid"></param>
        /// <param name="message"></param>
        void EventManager_OnOarFileSaved(Guid guid, string message)
        {
            // Ignore if the OAR save is being done by some other part of the system
            if (m_pendingSaves.ContainsKey(guid))
            {
                AutoBackupModuleState abms = m_states[(m_pendingSaves[guid])];
                ExecuteScript(abms.Script, abms.LiveRequests[guid]);
                m_pendingSaves.Remove(guid);
                abms.LiveRequests.Remove(guid);
            }
        }

        /// <summary>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? We support those, too!</summary>
        private static 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;
        }

        /// <summary>Return value of true ==> not too busy; false ==> too busy to backup an OAR right now, or error.</summary>
        private bool RunHeuristics(IScene region)
        {
            try
            {
                return this.RunTimeDilationHeuristic(region) && this.RunAgentLimitHeuristic(region);
            }
            catch (Exception e)
            {
                m_log.Warn("[AUTO BACKUP]: Exception in RunHeuristics", e);
                return false;
            }
        }

        /// <summary>
        /// If the time dilation right at this instant is less than the threshold specified in AutoBackupDilationThreshold (default 0.5),
        /// then we return false and trip the busy heuristic's "too busy" path (i.e. don't save an OAR).
        /// AutoBackupDilationThreshold is a _LOWER BOUND_. Lower Time Dilation is bad, so if you go lower than our threshold, it's "too busy".
        /// </summary>
        /// <param name="region"></param>
        /// <returns>Returns true if we're not too busy; false means we've got worse time dilation than the threshold.</returns>
        private bool RunTimeDilationHeuristic(IScene region)
        {
            string regionName = region.RegionInfo.RegionName;
            return region.TimeDilation >=
                   this.m_configSource.Configs["AutoBackupModule"].GetFloat(
                       regionName + ".AutoBackupDilationThreshold", 0.5f);
        }

        /// <summary>
        /// If the root agent count right at this instant is less than the threshold specified in AutoBackupAgentThreshold (default 10),
        /// then we return false and trip the busy heuristic's "too busy" path (i.e., don't save an OAR).
        /// AutoBackupAgentThreshold is an _UPPER BOUND_. Higher Agent Count is bad, so if you go higher than our threshold, it's "too busy".
        /// </summary>
        /// <param name="region"></param>
        /// <returns>Returns true if we're not too busy; false means we've got more agents on the sim than the threshold.</returns>
        private bool RunAgentLimitHeuristic(IScene region)
        {
            string regionName = region.RegionInfo.RegionName;
            try
            {
                Scene scene = (Scene) region;
                // TODO: Why isn't GetRootAgentCount() a method in the IScene interface? Seems generally useful...
                return scene.GetRootAgentCount() <=
                       this.m_configSource.Configs["AutoBackupModule"].GetInt(
                           regionName + ".AutoBackupAgentThreshold", 10);
            }
            catch (InvalidCastException ice)
            {
                m_log.Debug(
                    "[AUTO BACKUP]: I NEED MAINTENANCE: IScene is not a Scene; can't get root agent count!",
                    ice);
                return true;
                // Non-obstructionist safest answer...
            }
        }

        /// <summary>
        /// Run the script or executable specified by the "AutoBackupScript" config setting.
        /// Of course this is a security risk if you let anyone modify OpenSim.ini and they want to run some nasty bash script.
        /// But there are plenty of other nasty things that can be done with an untrusted OpenSim.ini, such as running high threat level scripting functions.
        /// </summary>
        /// <param name="scriptName"></param>
        /// <param name="savePath"></param>
        private static void ExecuteScript(string scriptName, string savePath)
        {
            // Do nothing if there's no script.
            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);
            }
        }

        /// <summary>
        /// Called if a running script process writes to stderr.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private static void HandleProcErrorDataReceived(object sender, DataReceivedEventArgs e)
        {
            m_log.Warn("ExecuteScript hook " + ((Process) sender).ProcessName +
                       " is yacking on stderr: " + e.Data);
        }

        /// <summary>
        /// Quickly stop all timers from firing.
        /// </summary>
        private void StopAllTimers()
        {
            foreach (Timer t in this.m_timerMap.Keys)
            {
                t.Close();
            }
            this.m_closed = true;
        }

        /// <summary>
        /// Determine the next unique filename by number, for "Sequential" AutoBackupNamingType.
        /// </summary>
        /// <param name="dirName"></param>
        /// <param name="regionName"></param>
        /// <returns></returns>
        private static string GetNextFile(string dirName, string regionName)
        {
            FileInfo uniqueFile = null;
            long biggestExistingFile = GetNextOarFileNumber(dirName, regionName);
            biggestExistingFile++;
            // We don't want to overwrite the biggest existing file; we want to write to the NEXT biggest.
            uniqueFile =
                new FileInfo(dirName + Path.DirectorySeparatorChar + regionName + "_" +
                             biggestExistingFile + ".oar");
            return uniqueFile.FullName;
        }

        /// <summary>
        /// Top-level method for creating an absolute path to an OAR backup file based on what naming scheme the user wants.
        /// </summary>
        /// <param name="regionName">Name of the region to save.</param>
        /// <param name="baseDir">Absolute or relative path to the directory where the file should reside.</param>
        /// <param name="naming">The naming scheme for the file name.</param>
        /// <returns></returns>
        private static string BuildOarPath(string regionName, string baseDir, NamingType naming)
        {
            FileInfo path = null;
            switch (naming)
            {
                case NamingType.Overwrite:
                    path = new FileInfo(baseDir + Path.DirectorySeparatorChar + regionName + ".oar");
                    return path.FullName;
                case NamingType.Time:
                    path =
                        new FileInfo(baseDir + Path.DirectorySeparatorChar + regionName +
                                     GetTimeString() + ".oar");
                    return path.FullName;
                case NamingType.Sequential:
                    // All codepaths in GetNextFile should return a file name ending in .oar
                    path = new FileInfo(GetNextFile(baseDir, regionName));
                    return path.FullName;
                default:
                    m_log.Warn("VERY BAD: Unhandled case element " + naming);
                    break;
            }

            return null;
        }

        /// <summary>
        /// Helper function for Sequential file naming type (see BuildOarPath and GetNextFile).
        /// </summary>
        /// <param name="dirName"></param>
        /// <param name="regionName"></param>
        /// <returns></returns>
        private static long GetNextOarFileNumber(string dirName, string regionName)
        {
            long retval = 1;

            DirectoryInfo di = new DirectoryInfo(dirName);
            FileInfo[] fi = di.GetFiles(regionName, SearchOption.TopDirectoryOnly);
            Array.Sort(fi, (f1, f2) => StringComparer.CurrentCultureIgnoreCase.Compare(f1.Name, f2.Name));

            if (fi.LongLength > 0)
            {
                long subtract = 1L;
                bool worked = false;
                Regex reg = new Regex(regionName + "_([0-9])+" + ".oar");

                while (!worked && subtract <= fi.LongLength)
                {
                    // Pick the file with the last natural ordering
                    string biggestFileName = fi[fi.LongLength - subtract].Name;
                    MatchCollection matches = reg.Matches(biggestFileName);
                    long l = 1;
                    if (matches.Count > 0 && matches[0].Groups.Count > 0)
                    {
                        try
                        {
                            long.TryParse(matches[0].Groups[1].Value, out l);
                            retval = l;
                            worked = true;
                        }
                        catch (FormatException fe)
                        {
                            m_log.Warn(
                                "[AUTO BACKUP]: Error: Can't parse long value from file name to determine next OAR backup file number!",
                                fe);
                            subtract++;
                        }
                    }
                    else
                    {
                        subtract++;
                    }
                }
            }
            return retval;
        }
    }
}