aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/OpenSim/Framework/WebUtil.cs
blob: c7f1bdb962be95494f5ca4737015d98ec7c51d96 (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
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
/*
 * 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;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Globalization;
using System.IO;
using System.IO.Compression;
using System.Net;
using System.Net.Security;
using System.Reflection;
using System.Text;
using System.Web;
using System.Xml;
using System.Xml.Serialization;
using log4net;
using OpenMetaverse.StructuredData;

namespace OpenSim.Framework
{
    /// <summary>
    /// Miscellaneous static methods and extension methods related to the web
    /// </summary>
    public static class WebUtil
    {
        private static readonly ILog m_log =
                LogManager.GetLogger(
                MethodBase.GetCurrentMethod().DeclaringType);

        /// <summary>
        /// Control the printing of certain debug messages.
        /// </summary>
        /// <remarks>
        /// If DebugLevel >= 3 then short notices about outgoing HTTP requests are logged.
        /// </remarks>
        public static int DebugLevel { get; set; }

        /// <summary>
        /// Request number for diagnostic purposes.
        /// </summary>
        public static int RequestNumber { get; internal set; }

        /// <summary>
        /// Control where OSD requests should be serialized per endpoint.
        /// </summary>
        public static bool SerializeOSDRequestsPerEndpoint { get; set; }

        /// <summary>
        /// this is the header field used to communicate the local request id
        /// used for performance and debugging
        /// </summary>
        public const string OSHeaderRequestID = "opensim-request-id";

        /// <summary>
        /// Number of milliseconds a call can take before it is considered
        /// a "long" call for warning & debugging purposes
        /// </summary>
        public const int LongCallTime = 3000;

        /// <summary>
        /// The maximum length of any data logged because of a long request time.
        /// </summary>
        /// <remarks>
        /// This is to truncate any really large post data, such as an asset.  In theory, the first section should
        /// give us useful information about the call (which agent it relates to if applicable, etc.).
        /// </remarks>
        public const int MaxRequestDiagLength = 100;

        /// <summary>
        /// Dictionary of end points
        /// </summary>
        private static Dictionary<string,object> m_endpointSerializer = new Dictionary<string,object>();

        private static object EndPointLock(string url)
        {
            System.Uri uri = new System.Uri(url);
            string endpoint = string.Format("{0}:{1}",uri.Host,uri.Port);

            lock (m_endpointSerializer)
            {
                object eplock = null;

                if (! m_endpointSerializer.TryGetValue(endpoint,out eplock))
                {
                    eplock = new object();
                    m_endpointSerializer.Add(endpoint,eplock);
                    // m_log.WarnFormat("[WEB UTIL] add a new host to end point serializer {0}",endpoint);
                }

                return eplock;
            }
        }

        #region JSONRequest

        /// <summary>
        /// PUT JSON-encoded data to a web service that returns LLSD or
        /// JSON data
        /// </summary>
        public static OSDMap PutToServiceCompressed(string url, OSDMap data, int timeout)
        {
            return ServiceOSDRequest(url,data, "PUT", timeout, true);
        }

        public static OSDMap PutToService(string url, OSDMap data, int timeout)
        {
            return ServiceOSDRequest(url,data, "PUT", timeout, false);
        }

        public static OSDMap PostToService(string url, OSDMap data, int timeout)
        {
            return ServiceOSDRequest(url, data, "POST", timeout, false);
        }

        public static OSDMap PostToServiceCompressed(string url, OSDMap data, int timeout)
        {
            return ServiceOSDRequest(url, data, "POST", timeout, true);
        }

        public static OSDMap GetFromService(string url, int timeout)
        {
            return ServiceOSDRequest(url, null, "GET", timeout, false);
        }
        
        public static OSDMap ServiceOSDRequest(string url, OSDMap data, string method, int timeout, bool compressed)
        {
            if (SerializeOSDRequestsPerEndpoint)
            {
                lock (EndPointLock(url))
                {
                    return ServiceOSDRequestWorker(url, data, method, timeout, compressed);
                }
            }
            else
            {
                return ServiceOSDRequestWorker(url, data, method, timeout, compressed);
            }
        }

        public static void LogOutgoingDetail(Stream outputStream)
        {
            using (StreamReader reader = new StreamReader(Util.Copy(outputStream), Encoding.UTF8))
            {
                string output;

                if (DebugLevel == 5)
                {
                    const int sampleLength = 80;
                    char[] sampleChars = new char[sampleLength];
                    reader.Read(sampleChars, 0, sampleLength);
                    output = new string(sampleChars);
                }
                else
                {
                    output = reader.ReadToEnd();
                }

                LogOutgoingDetail(output);
            }
        }

        public static void LogOutgoingDetail(string output)
        {
            if (DebugLevel == 5)
            {
                output = output.Substring(0, 80);
                output = output + "...";
            }

            m_log.DebugFormat("[WEB UTIL]: {0}", output.Replace("\n", @"\n"));
        }

        private static OSDMap ServiceOSDRequestWorker(string url, OSDMap data, string method, int timeout, bool compressed)
        {
            int reqnum = RequestNumber++;

            if (DebugLevel >= 3)
                m_log.DebugFormat(
                    "[WEB UTIL]: HTTP OUT {0} ServiceOSD {1} {2} (timeout {3}, compressed {4})",
                    reqnum, method, url, timeout, compressed);

            string errorMessage = "unknown error";
            int tickstart = Util.EnvironmentTickCount();
            int tickdata = 0;
            string strBuffer = null;

            try
            {
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
                request.Method = method;
                request.Timeout = timeout;
                request.KeepAlive = false;
                request.MaximumAutomaticRedirections = 10;
                request.ReadWriteTimeout = timeout / 4;
                request.Headers[OSHeaderRequestID] = reqnum.ToString();
                
                // If there is some input, write it into the request
                if (data != null)
                {
                    strBuffer = OSDParser.SerializeJsonString(data);

                    if (DebugLevel >= 5)
                        LogOutgoingDetail(strBuffer);

                    byte[] buffer = System.Text.Encoding.UTF8.GetBytes(strBuffer);

                    if (compressed)
                    {
                        request.ContentType = "application/x-gzip";
                        using (MemoryStream ms = new MemoryStream())
                        {
                            using (GZipStream comp = new GZipStream(ms, CompressionMode.Compress))
                            {
                                comp.Write(buffer, 0, buffer.Length);
                                // We need to close the gzip stream before we write it anywhere
                                // because apparently something important related to gzip compression
                                // gets written on the strteam upon Dispose()
                            }
                            byte[] buf = ms.ToArray();
                            request.ContentLength = buf.Length;   //Count bytes to send
                            using (Stream requestStream = request.GetRequestStream())
                                requestStream.Write(buf, 0, (int)buf.Length);
                        }
                    }
                    else
                    {
                        request.ContentType = "application/json";
                        request.ContentLength = buffer.Length;   //Count bytes to send
                        using (Stream requestStream = request.GetRequestStream())
                                requestStream.Write(buffer, 0, buffer.Length);         //Send it
                    }
                }
                
                // capture how much time was spent writing, this may seem silly
                // but with the number concurrent requests, this often blocks
                tickdata = Util.EnvironmentTickCountSubtract(tickstart);

                using (WebResponse response = request.GetResponse())
                {
                    using (Stream responseStream = response.GetResponseStream())
                    {
                        using (StreamReader reader = new StreamReader(responseStream))
                        {
                            string responseStr = reader.ReadToEnd();
                            // m_log.DebugFormat("[WEB UTIL]: <{0}> response is <{1}>",reqnum,responseStr);
                            return CanonicalizeResults(responseStr);
                        }
                    }
                }
            }
            catch (WebException we)
            {
                errorMessage = we.Message;
                if (we.Status == WebExceptionStatus.ProtocolError)
                {
                    using (HttpWebResponse webResponse = (HttpWebResponse)we.Response)
                        errorMessage = String.Format("[{0}] {1}", webResponse.StatusCode, webResponse.StatusDescription);
                }
            }
            catch (Exception ex)
            {
                errorMessage = ex.Message;
            }
            finally
            {
                int tickdiff = Util.EnvironmentTickCountSubtract(tickstart);
                if (tickdiff > LongCallTime)
                    m_log.InfoFormat(
                        "[WEB UTIL]: Slow ServiceOSD request {0} {1} {2} took {3}ms, {4}ms writing, {5}",
                        reqnum,
                        method,
                        url,
                        tickdiff,
                        tickdata,
                        strBuffer != null
                            ? (strBuffer.Length > MaxRequestDiagLength ? strBuffer.Remove(MaxRequestDiagLength) : strBuffer)
                            : "");
                else if (DebugLevel >= 4)
                    m_log.DebugFormat(
                        "[WEB UTIL]: HTTP OUT {0} took {1}ms, {2}ms writing",
                        reqnum, tickdiff, tickdata);
            }
           
            m_log.DebugFormat(
                "[WEB UTIL]: ServiceOSD request {0} {1} {2} FAILED: {3}", reqnum, url, method, errorMessage);

            return ErrorResponseMap(errorMessage);
        }

        /// <summary>
        /// Since there are no consistencies in the way web requests are
        /// formed, we need to do a little guessing about the result format.
        /// Keys:
        ///     Success|success == the success fail of the request
        ///     _RawResult == the raw string that came back
        ///     _Result == the OSD unpacked string
        /// </summary>
        private static OSDMap CanonicalizeResults(string response)
        {
            OSDMap result = new OSDMap();

            // Default values
            result["Success"] = OSD.FromBoolean(true);
            result["success"] = OSD.FromBoolean(true);
            result["_RawResult"] = OSD.FromString(response);
            result["_Result"] = new OSDMap();
            
            if (response.Equals("true",System.StringComparison.OrdinalIgnoreCase))
                return result;

            if (response.Equals("false",System.StringComparison.OrdinalIgnoreCase))
            {
                result["Success"] = OSD.FromBoolean(false);
                result["success"] = OSD.FromBoolean(false);
                return result;
            }

            try 
            {
                OSD responseOSD = OSDParser.Deserialize(response);
                if (responseOSD.Type == OSDType.Map)
                {
                    result["_Result"] = (OSDMap)responseOSD;
                    return result;
                }
            }
            catch
            {
                // don't need to treat this as an error... we're just guessing anyway
//                m_log.DebugFormat("[WEB UTIL] couldn't decode <{0}>: {1}",response,e.Message);
            }
            
            return result;
        }
        
        #endregion JSONRequest

        #region FormRequest

        /// <summary>
        /// POST URL-encoded form data to a web service that returns LLSD or
        /// JSON data
        /// </summary>
        public static OSDMap PostToService(string url, NameValueCollection data)
        {
            return ServiceFormRequest(url,data,10000);
        }
        
        public static OSDMap ServiceFormRequest(string url, NameValueCollection data, int timeout)
        {
            lock (EndPointLock(url))
            {
                return ServiceFormRequestWorker(url,data,timeout);
            }
        }

        private static OSDMap ServiceFormRequestWorker(string url, NameValueCollection data, int timeout)
        {
            int reqnum = RequestNumber++;
            string method = (data != null && data["RequestMethod"] != null) ? data["RequestMethod"] : "unknown";

            if (DebugLevel >= 3)
                m_log.DebugFormat(
                    "[WEB UTIL]: HTTP OUT {0} ServiceForm {1} {2} (timeout {3})",
                    reqnum, method, url, timeout);
            
            string errorMessage = "unknown error";
            int tickstart = Util.EnvironmentTickCount();
            int tickdata = 0;
            string queryString = null;

            try
            {
                HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
                request.Method = "POST";
                request.Timeout = timeout;
                request.KeepAlive = false;
                request.MaximumAutomaticRedirections = 10;
                request.ReadWriteTimeout = timeout / 4;
                request.Headers[OSHeaderRequestID] = reqnum.ToString();
                
                if (data != null)
                {
                    queryString = BuildQueryString(data);

                    if (DebugLevel >= 5)
                        LogOutgoingDetail(queryString);

                    byte[] buffer = System.Text.Encoding.UTF8.GetBytes(queryString);
                    
                    request.ContentLength = buffer.Length;
                    request.ContentType = "application/x-www-form-urlencoded";
                    using (Stream requestStream = request.GetRequestStream())
                        requestStream.Write(buffer, 0, buffer.Length);
                }

                // capture how much time was spent writing, this may seem silly
                // but with the number concurrent requests, this often blocks
                tickdata = Util.EnvironmentTickCountSubtract(tickstart);

                using (WebResponse response = request.GetResponse())
                {
                    using (Stream responseStream = response.GetResponseStream())
                    {
                        using (StreamReader reader = new StreamReader(responseStream))
                        {
                            string responseStr = reader.ReadToEnd();
                            OSD responseOSD = OSDParser.Deserialize(responseStr);

                            if (responseOSD.Type == OSDType.Map)
                                return (OSDMap)responseOSD;
                        }
                    }
                }
            }
            catch (WebException we)
            {
                errorMessage = we.Message;
                if (we.Status == WebExceptionStatus.ProtocolError)
                {
                    using (HttpWebResponse webResponse = (HttpWebResponse)we.Response)
                        errorMessage = String.Format("[{0}] {1}",webResponse.StatusCode,webResponse.StatusDescription);
                }
            }
            catch (Exception ex)
            {
                errorMessage = ex.Message;
            }
            finally
            {
                int tickdiff = Util.EnvironmentTickCountSubtract(tickstart);
                if (tickdiff > LongCallTime)
                    m_log.InfoFormat(
                        "[WEB UTIL]: Slow ServiceForm request {0} {1} {2} took {3}ms, {4}ms writing, {5}",
                        reqnum,
                        method,
                        url,
                        tickdiff,
                        tickdata,
                        queryString != null
                            ? (queryString.Length > MaxRequestDiagLength) ? queryString.Remove(MaxRequestDiagLength) : queryString
                            : "");
                else if (DebugLevel >= 4)
                    m_log.DebugFormat(
                        "[WEB UTIL]: HTTP OUT {0} took {1}ms, {2}ms writing",
                        reqnum, tickdiff, tickdata);
            }

            m_log.WarnFormat("[WEB UTIL]: ServiceForm request {0} {1} {2} failed: {2}", reqnum, method, url, errorMessage);

            return ErrorResponseMap(errorMessage);
        }

        /// <summary>
        /// Create a response map for an error, trying to keep
        /// the result formats consistent
        /// </summary>
        private static OSDMap ErrorResponseMap(string msg)
        {
            OSDMap result = new OSDMap();
            result["Success"] = "False";
            result["Message"] = OSD.FromString("Service request failed: " + msg);
            return result;
        }

        #endregion FormRequest
        
        #region Uri

        /// <summary>
        /// Combines a Uri that can contain both a base Uri and relative path
        /// with a second relative path fragment
        /// </summary>
        /// <param name="uri">Starting (base) Uri</param>
        /// <param name="fragment">Relative path fragment to append to the end
        /// of the Uri</param>
        /// <returns>The combined Uri</returns>
        /// <remarks>This is similar to the Uri constructor that takes a base
        /// Uri and the relative path, except this method can append a relative
        /// path fragment on to an existing relative path</remarks>
        public static Uri Combine(this Uri uri, string fragment)
        {
            string fragment1 = uri.Fragment;
            string fragment2 = fragment;

            if (!fragment1.EndsWith("/"))
                fragment1 = fragment1 + '/';
            if (fragment2.StartsWith("/"))
                fragment2 = fragment2.Substring(1);

            return new Uri(uri, fragment1 + fragment2);
        }

        /// <summary>
        /// Combines a Uri that can contain both a base Uri and relative path
        /// with a second relative path fragment. If the fragment is absolute,
        /// it will be returned without modification
        /// </summary>
        /// <param name="uri">Starting (base) Uri</param>
        /// <param name="fragment">Relative path fragment to append to the end
        /// of the Uri, or an absolute Uri to return unmodified</param>
        /// <returns>The combined Uri</returns>
        public static Uri Combine(this Uri uri, Uri fragment)
        {
            if (fragment.IsAbsoluteUri)
                return fragment;

            string fragment1 = uri.Fragment;
            string fragment2 = fragment.ToString();

            if (!fragment1.EndsWith("/"))
                fragment1 = fragment1 + '/';
            if (fragment2.StartsWith("/"))
                fragment2 = fragment2.Substring(1);

            return new Uri(uri, fragment1 + fragment2);
        }

        /// <summary>
        /// Appends a query string to a Uri that may or may not have existing 
        /// query parameters
        /// </summary>
        /// <param name="uri">Uri to append the query to</param>
        /// <param name="query">Query string to append. Can either start with ?
        /// or just containg key/value pairs</param>
        /// <returns>String representation of the Uri with the query string
        /// appended</returns>
        public static string AppendQuery(this Uri uri, string query)
        {
            if (String.IsNullOrEmpty(query))
                return uri.ToString();

            if (query[0] == '?' || query[0] == '&')
                query = query.Substring(1);

            string uriStr = uri.ToString();

            if (uriStr.Contains("?"))
                return uriStr + '&' + query;
            else
                return uriStr + '?' + query;
        }

        #endregion Uri

        #region NameValueCollection

        /// <summary>
        /// Convert a NameValueCollection into a query string. This is the
        /// inverse of HttpUtility.ParseQueryString()
        /// </summary>
        /// <param name="parameters">Collection of key/value pairs to convert</param>
        /// <returns>A query string with URL-escaped values</returns>
        public static string BuildQueryString(NameValueCollection parameters)
        {
            List<string> items = new List<string>(parameters.Count);

            foreach (string key in parameters.Keys)
            {
                string[] values = parameters.GetValues(key);
                if (values != null)
                {
                    foreach (string value in values)
                        items.Add(String.Concat(key, "=", HttpUtility.UrlEncode(value ?? String.Empty)));
                }
            }

            return String.Join("&", items.ToArray());
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="collection"></param>
        /// <param name="key"></param>
        /// <returns></returns>
        public static string GetOne(this NameValueCollection collection, string key)
        {
            string[] values = collection.GetValues(key);
            if (values != null && values.Length > 0)
                return values[0];

            return null;
        }

        #endregion NameValueCollection

        #region Stream

        /// <summary>
        /// Copies the contents of one stream to another, starting at the 
        /// current position of each stream
        /// </summary>
        /// <param name="copyFrom">The stream to copy from, at the position 
        /// where copying should begin</param>
        /// <param name="copyTo">The stream to copy to, at the position where 
        /// bytes should be written</param>
        /// <param name="maximumBytesToCopy">The maximum bytes to copy</param>
        /// <returns>The total number of bytes copied</returns>
        /// <remarks>
        /// Copying begins at the streams' current positions. The positions are
        /// NOT reset after copying is complete.
        /// NOTE!! .NET 4.0 adds the method 'Stream.CopyTo(stream, bufferSize)'.
        /// This function could be replaced with that method once we move
        /// totally to .NET 4.0. For versions before, this routine exists.
        /// This routine used to be named 'CopyTo' but the int parameter has
        /// a different meaning so this method was renamed to avoid any confusion.
        /// </remarks>
        public static int CopyStream(this Stream copyFrom, Stream copyTo, int maximumBytesToCopy)
        {
            byte[] buffer = new byte[4096];
            int readBytes;
            int totalCopiedBytes = 0;

            while ((readBytes = copyFrom.Read(buffer, 0, Math.Min(4096, maximumBytesToCopy))) > 0)
            {
                int writeBytes = Math.Min(maximumBytesToCopy, readBytes);
                copyTo.Write(buffer, 0, writeBytes);
                totalCopiedBytes += writeBytes;
                maximumBytesToCopy -= writeBytes;
            }

            return totalCopiedBytes;
        }

        #endregion Stream

        public class QBasedComparer : IComparer
        {
            public int Compare(Object x, Object y)
            {
                float qx = GetQ(x);
                float qy = GetQ(y);
                return qy.CompareTo(qx); // descending order
            }

            private float GetQ(Object o)
            {
                // Example: image/png;q=0.9

                float qvalue = 1F;
                if (o is String)
                {
                    string mime = (string)o;
                    string[] parts = mime.Split(';');
                    if (parts.Length > 1)
                    {
                        string[] kvp = parts[1].Split('=');
                        if (kvp.Length == 2 && kvp[0] == "q")
                            float.TryParse(kvp[1], NumberStyles.Number, CultureInfo.InvariantCulture, out qvalue);
                    }
                }

                return qvalue;
            }
        }

        /// <summary>
        /// Takes the value of an Accept header and returns the preferred types
        /// ordered by q value (if it exists).
        /// Example input: image/jpg;q=0.7, image/png;q=0.8, image/jp2
        /// Exmaple output: ["jp2", "png", "jpg"]
        /// NOTE: This doesn't handle the semantics of *'s...
        /// </summary>
        /// <param name="accept"></param>
        /// <returns></returns>
        public static string[] GetPreferredImageTypes(string accept)
        {
            if (string.IsNullOrEmpty(accept))
                return new string[0];

            string[] types = accept.Split(new char[] { ',' });
            if (types.Length > 0)
            {
                List<string> list = new List<string>(types);
                list.RemoveAll(delegate(string s) { return !s.ToLower().StartsWith("image"); });
                ArrayList tlist = new ArrayList(list);
                tlist.Sort(new QBasedComparer());

                string[] result = new string[tlist.Count];
                for (int i = 0; i < tlist.Count; i++)
                {
                    string mime = (string)tlist[i];
                    string[] parts = mime.Split(new char[] { ';' });
                    string[] pair = parts[0].Split(new char[] { '/' });
                    if (pair.Length == 2)
                        result[i] = pair[1].ToLower();
                    else // oops, we don't know what this is...
                        result[i] = pair[0];
                }

                return result;
            }

            return new string[0];
        }
    }

    public static class AsynchronousRestObjectRequester
    {
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        /// <summary>
        /// Perform an asynchronous REST request.
        /// </summary>
        /// <param name="verb">GET or POST</param>
        /// <param name="requestUrl"></param>
        /// <param name="obj"></param>
        /// <param name="action"></param>
        /// <returns></returns>
        ///
        /// <exception cref="System.Net.WebException">Thrown if we encounter a
        /// network issue while posting the request.  You'll want to make
        /// sure you deal with this as they're not uncommon</exception>
        //
        public static void MakeRequest<TRequest, TResponse>(string verb,
                string requestUrl, TRequest obj, Action<TResponse> action)
        {
            MakeRequest<TRequest, TResponse>(verb, requestUrl, obj, action, 0);
        }

        public static void MakeRequest<TRequest, TResponse>(string verb,
                string requestUrl, TRequest obj, Action<TResponse> action,
                int maxConnections)
        {
            int reqnum = WebUtil.RequestNumber++;

            if (WebUtil.DebugLevel >= 3)
                m_log.DebugFormat(
                    "[WEB UTIL]: HTTP OUT {0} AsynchronousRequestObject {1} {2}",
                    reqnum, verb, requestUrl);

            int tickstart = Util.EnvironmentTickCount();
            int tickdata = 0;

            Type type = typeof(TRequest);

            WebRequest request = WebRequest.Create(requestUrl);
            HttpWebRequest ht = (HttpWebRequest)request;
            if (maxConnections > 0 && ht.ServicePoint.ConnectionLimit < maxConnections)
                ht.ServicePoint.ConnectionLimit = maxConnections;

            TResponse deserial = default(TResponse);
            XmlSerializer deserializer = new XmlSerializer(typeof(TResponse));

            request.Method = verb;

            MemoryStream buffer = null;

            try
            {
                if (verb == "POST")
                {
                    request.ContentType = "text/xml";

                    buffer = new MemoryStream();

                    XmlWriterSettings settings = new XmlWriterSettings();
                    settings.Encoding = Encoding.UTF8;

                    using (XmlWriter writer = XmlWriter.Create(buffer, settings))
                    {
                        XmlSerializer serializer = new XmlSerializer(type);
                        serializer.Serialize(writer, obj);
                        writer.Flush();
                    }

                    int length = (int)buffer.Length;
                    request.ContentLength = length;

                    if (WebUtil.DebugLevel >= 5)
                        WebUtil.LogOutgoingDetail(buffer);

                    request.BeginGetRequestStream(delegate(IAsyncResult res)
                    {
                        using (Stream requestStream = request.EndGetRequestStream(res))
                            requestStream.Write(buffer.ToArray(), 0, length);

                        // capture how much time was spent writing
                        tickdata = Util.EnvironmentTickCountSubtract(tickstart);

                        request.BeginGetResponse(delegate(IAsyncResult ar)
                        {
                            using (WebResponse response = request.EndGetResponse(ar))
                            {
                                try
                                {
                                    using (Stream respStream = response.GetResponseStream())
                                        deserial = (TResponse)deserializer.Deserialize(respStream);
                                }
                                catch (System.InvalidOperationException)
                                {
                                }
                            }

                            action(deserial);

                        }, null);
                    }, null);
                }
                else
                {
                    request.BeginGetResponse(delegate(IAsyncResult res2)
                    {
                        try
                        {
                            // If the server returns a 404, this appears to trigger a System.Net.WebException even though that isn't
                            // documented in MSDN
                            using (WebResponse response = request.EndGetResponse(res2))
                            {   
                                try
                                {
                                    using (Stream respStream = response.GetResponseStream())
                                        deserial = (TResponse)deserializer.Deserialize(respStream);
                                }
                                catch (System.InvalidOperationException)
                                {
                                }
                            }
                        }
                        catch (WebException e)
                        {
                            if (e.Status == WebExceptionStatus.ProtocolError)
                            {
                                if (e.Response is HttpWebResponse)
                                {
                                    using (HttpWebResponse httpResponse = (HttpWebResponse)e.Response)
                                    {        
                                        if (httpResponse.StatusCode != HttpStatusCode.NotFound)
                                        {
                                            // We don't appear to be handling any other status codes, so log these feailures to that
                                            // people don't spend unnecessary hours hunting phantom bugs.
                                            m_log.DebugFormat(
                                                "[ASYNC REQUEST]: Request {0} {1} failed with unexpected status code {2}",
                                                verb, requestUrl, httpResponse.StatusCode);
                                        }
                                    }
                                }
                            }
                            else
                            {
                                m_log.ErrorFormat(
                                    "[ASYNC REQUEST]: Request {0} {1} failed with status {2} and message {3}",
                                    verb, requestUrl, e.Status, e.Message);
                            }
                        }
                        catch (Exception e)
                        {
                            m_log.ErrorFormat(
                                "[ASYNC REQUEST]: Request {0} {1} failed with exception {2}{3}",
                                verb, requestUrl, e.Message, e.StackTrace);
                        }
        
                        //  m_log.DebugFormat("[ASYNC REQUEST]: Received {0}", deserial.ToString());

                        try
                        {
                            action(deserial);
                        }
                        catch (Exception e)
                        {
                            m_log.ErrorFormat(
                                "[ASYNC REQUEST]: Request {0} {1} callback failed with exception {2}{3}",
                                verb, requestUrl, e.Message, e.StackTrace);
                        }
        
                    }, null);
                }

                int tickdiff = Util.EnvironmentTickCountSubtract(tickstart);
                if (tickdiff > WebUtil.LongCallTime)
                {
                    string originalRequest = null;

                    if (buffer != null)
                    {
                        originalRequest = Encoding.UTF8.GetString(buffer.ToArray());

                        if (originalRequest.Length > WebUtil.MaxRequestDiagLength)
                            originalRequest = originalRequest.Remove(WebUtil.MaxRequestDiagLength);
                    }

                    m_log.InfoFormat(
                        "[ASYNC REQUEST]: Slow request {0} {1} {2} took {3}ms, {4}ms writing, {5}",
                        reqnum,
                        verb,
                        requestUrl,
                        tickdiff,
                        tickdata,
                        originalRequest);
                }
                else if (WebUtil.DebugLevel >= 4)
                {
                    m_log.DebugFormat(
                        "[WEB UTIL]: HTTP OUT {0} took {1}ms, {2}ms writing",
                        reqnum, tickdiff, tickdata);
                }
            }
            finally
            { 
                if (buffer != null)
                    buffer.Dispose();
            }
        }
    }

    public static class SynchronousRestFormsRequester
    {
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        /// <summary>
        /// Perform a synchronous REST request.
        /// </summary>
        /// <param name="verb"></param>
        /// <param name="requestUrl"></param>
        /// <param name="obj"> </param>
        /// <param name="timeoutsecs"> </param>
        /// <returns></returns>
        ///
        /// <exception cref="System.Net.WebException">Thrown if we encounter a network issue while posting
        /// the request.  You'll want to make sure you deal with this as they're not uncommon</exception>
        public static string MakeRequest(string verb, string requestUrl, string obj, int timeoutsecs)
        {
            int reqnum = WebUtil.RequestNumber++;

            if (WebUtil.DebugLevel >= 3)
                m_log.DebugFormat(
                    "[WEB UTIL]: HTTP OUT {0} SynchronousRestForms {1} {2}",
                    reqnum, verb, requestUrl);

            int tickstart = Util.EnvironmentTickCount();
            int tickdata = 0;

            WebRequest request = WebRequest.Create(requestUrl);
            request.Method = verb;
            if (timeoutsecs > 0)
                request.Timeout = timeoutsecs * 1000;
            string respstring = String.Empty;

            using (MemoryStream buffer = new MemoryStream())
            {
                if ((verb == "POST") || (verb == "PUT"))
                {
                    request.ContentType = "application/x-www-form-urlencoded";

                    int length = 0;
                    using (StreamWriter writer = new StreamWriter(buffer))
                    {
                        writer.Write(obj);
                        writer.Flush();
                    }

                    length = (int)obj.Length;
                    request.ContentLength = length;

                    if (WebUtil.DebugLevel >= 5)
                        WebUtil.LogOutgoingDetail(buffer);

                    Stream requestStream = null;
                    try
                    {
                        requestStream = request.GetRequestStream();
                        requestStream.Write(buffer.ToArray(), 0, length);
                    }
                    catch (Exception e)
                    {
                        m_log.DebugFormat(
                            "[FORMS]: exception occured {0} {1}: {2}{3}", verb, requestUrl, e.Message, e.StackTrace);
                    }
                    finally
                    {
                        if (requestStream != null)
                            requestStream.Dispose();

                        // capture how much time was spent writing
                        tickdata = Util.EnvironmentTickCountSubtract(tickstart);
                    }
                }

                try
                {
                    using (WebResponse resp = request.GetResponse())
                    {
                        if (resp.ContentLength != 0)
                        {
                            Stream respStream = null;
                            try
                            {
                                using (respStream = resp.GetResponseStream())
                                    using (StreamReader reader = new StreamReader(respStream))
                                        respstring = reader.ReadToEnd();
                            }
                            catch (Exception e)
                            {
                                m_log.DebugFormat(
                                    "[FORMS]: Exception occured on receiving {0} {1}: {2}{3}",
                                    verb, requestUrl, e.Message, e.StackTrace);
                            }
                        }
                    }
                }
                catch (System.InvalidOperationException e)
                {
                    m_log.Debug(
                        string.Format(
                            "[FORMS]: InvalidOperationException on response from {0} {1}  ", verb, requestUrl), e);
                }
            }

            int tickdiff = Util.EnvironmentTickCountSubtract(tickstart);
            if (tickdiff > WebUtil.LongCallTime)
                m_log.InfoFormat(
                    "[FORMS]: Slow request {0} {1} {2} took {3}ms, {4}ms writing, {5}",
                    reqnum,
                    verb,
                    requestUrl,
                    tickdiff,
                    tickdata,
                    obj.Length > WebUtil.MaxRequestDiagLength ? obj.Remove(WebUtil.MaxRequestDiagLength) : obj);
            else if (WebUtil.DebugLevel >= 4)
                m_log.DebugFormat(
                    "[WEB UTIL]: HTTP OUT {0} took {1}ms, {2}ms writing",
                    reqnum, tickdiff, tickdata);

            return respstring;
        }

        public static string MakeRequest(string verb, string requestUrl, string obj)
        {
            return MakeRequest(verb, requestUrl, obj, -1);
        }
    }

    public class SynchronousRestObjectRequester
    {
        private static readonly ILog m_log =
            LogManager.GetLogger(
            MethodBase.GetCurrentMethod().DeclaringType);

        /// <summary>
        /// Perform a synchronous REST request.
        /// </summary>
        /// <param name="verb"></param>
        /// <param name="requestUrl"></param>
        /// <param name="obj"> </param>
        /// <returns></returns>
        ///
        /// <exception cref="System.Net.WebException">Thrown if we encounter a network issue while posting
        /// the request.  You'll want to make sure you deal with this as they're not uncommon</exception>
        public static TResponse MakeRequest<TRequest, TResponse>(string verb, string requestUrl, TRequest obj)
        {
            return MakeRequest<TRequest, TResponse>(verb, requestUrl, obj, 0);
        }

        public static TResponse MakeRequest<TRequest, TResponse>(string verb, string requestUrl, TRequest obj, int pTimeout)
        {
            return MakeRequest<TRequest, TResponse>(verb, requestUrl, obj, pTimeout, 0);
        }

        public static TResponse MakeRequest<TRequest, TResponse>(string verb, string requestUrl, TRequest obj, int pTimeout, int maxConnections)
        {
            int reqnum = WebUtil.RequestNumber++;

            if (WebUtil.DebugLevel >= 3)
                m_log.DebugFormat(
                    "[WEB UTIL]: HTTP OUT {0} SynchronousRestObject {1} {2}",
                    reqnum, verb, requestUrl);

            int tickstart = Util.EnvironmentTickCount();
            int tickdata = 0;

            Type type = typeof(TRequest);
            TResponse deserial = default(TResponse);

            WebRequest request = WebRequest.Create(requestUrl);
            HttpWebRequest ht = (HttpWebRequest)request;
            if (maxConnections > 0 && ht.ServicePoint.ConnectionLimit < maxConnections)
                ht.ServicePoint.ConnectionLimit = maxConnections;

            request.Method = verb;
            MemoryStream buffer = null;

            try
            {
                if ((verb == "POST") || (verb == "PUT"))
                {
                    request.ContentType = "text/xml";

                    buffer = new MemoryStream();

                    XmlWriterSettings settings = new XmlWriterSettings();
                    settings.Encoding = Encoding.UTF8;

                    using (XmlWriter writer = XmlWriter.Create(buffer, settings))
                    {
                        XmlSerializer serializer = new XmlSerializer(type);
                        serializer.Serialize(writer, obj);
                        writer.Flush();
                    }

                    int length = (int)buffer.Length;
                    request.ContentLength = length;

                    if (WebUtil.DebugLevel >= 5)
                        WebUtil.LogOutgoingDetail(buffer);

                    try
                    {
                        using (Stream requestStream = request.GetRequestStream())
                            requestStream.Write(buffer.ToArray(), 0, length);
                    }
                    catch (Exception e)
                    {
                        m_log.DebugFormat(
                            "[SynchronousRestObjectRequester]: Exception in making request {0} {1}: {2}{3}",
                            verb, requestUrl, e.Message, e.StackTrace);

                        return deserial;
                    }
                    finally
                    {
                        // capture how much time was spent writing
                        tickdata = Util.EnvironmentTickCountSubtract(tickstart);
                    }
                }

                try
                {
                    using (HttpWebResponse resp = (HttpWebResponse)request.GetResponse())
                    {
                        if (resp.ContentLength != 0)
                        {
                            using (Stream respStream = resp.GetResponseStream())
                            {
                                XmlSerializer deserializer = new XmlSerializer(typeof(TResponse));
                                deserial = (TResponse)deserializer.Deserialize(respStream);
                            }
                        }
                        else
                        {
                            m_log.DebugFormat(
                                "[SynchronousRestObjectRequester]: Oops! no content found in response stream from {0} {1}",
                                verb, requestUrl);
                        }
                    }
                }
                catch (WebException e)
                {
                    using (HttpWebResponse hwr = (HttpWebResponse)e.Response)
                    {
                        if (hwr != null && hwr.StatusCode == HttpStatusCode.NotFound)
                            return deserial;
                        else
                            m_log.ErrorFormat(
                                "[SynchronousRestObjectRequester]: WebException for {0} {1} {2}: {3} {4}",
                                verb, requestUrl, typeof(TResponse).ToString(), e.Message, e.StackTrace);
                    }
                }
                catch (System.InvalidOperationException)
                {
                    // This is what happens when there is invalid XML
                    m_log.DebugFormat(
                        "[SynchronousRestObjectRequester]: Invalid XML from {0} {1} {2}",
                        verb, requestUrl, typeof(TResponse).ToString());
                }
                catch (Exception e)
                {
                    m_log.DebugFormat(
                        "[SynchronousRestObjectRequester]: Exception on response from {0} {1}: {2}{3}",
                        verb, requestUrl, e.Message, e.StackTrace);
                }

                int tickdiff = Util.EnvironmentTickCountSubtract(tickstart);
                if (tickdiff > WebUtil.LongCallTime)
                {
                    string originalRequest = null;

                    if (buffer != null)
                    {
                        originalRequest = Encoding.UTF8.GetString(buffer.ToArray());

                        if (originalRequest.Length > WebUtil.MaxRequestDiagLength)
                            originalRequest = originalRequest.Remove(WebUtil.MaxRequestDiagLength);
                    }

                    m_log.InfoFormat(
                        "[SynchronousRestObjectRequester]: Slow request {0} {1} {2} took {3}ms, {4}ms writing, {5}",
                        reqnum,
                        verb,
                        requestUrl,
                        tickdiff,
                        tickdata,
                        originalRequest);
                }
                else if (WebUtil.DebugLevel >= 4)
                {
                    m_log.DebugFormat(
                        "[WEB UTIL]: HTTP OUT {0} took {1}ms, {2}ms writing",
                        reqnum, tickdiff, tickdata);
                }
            }
            finally
            {
                if (buffer != null)
                    buffer.Dispose();
            }

            return deserial;
        }
    }
}