// // RKHTTPUtilities.m // RestKit // // Created by Blake Watters on 8/24/12. // Copyright (c) 2012 RestKit. All rights reserved. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // #import "RKHTTPUtilities.h" NSUInteger RKStatusCodeRangeLength = 100; NSRange RKStatusCodeRangeForClass(RKStatusCodeClass statusCodeClass) { return NSMakeRange(statusCodeClass, RKStatusCodeRangeLength); } NSIndexSet *RKStatusCodeIndexSetForClass(RKStatusCodeClass statusCodeClass) { return [NSIndexSet indexSetWithIndexesInRange:RKStatusCodeRangeForClass(statusCodeClass)]; } NSString *RKStringFromRequestMethod(RKRequestMethod method) { switch (method) { case RKRequestMethodGET: return @"GET"; case RKRequestMethodPOST: return @"POST"; case RKRequestMethodPUT: return @"PUT"; case RKRequestMethodPATCH: return @"PATCH"; case RKRequestMethodDELETE: return @"DELETE"; case RKRequestMethodHEAD: return @"HEAD"; case RKRequestMethodOPTIONS: return @"OPTIONS"; default: break; } return nil; } RKRequestMethod RKRequestMethodFromString(NSString *methodName) { if ([methodName isEqualToString:@"GET"]) return RKRequestMethodGET; else if ([methodName isEqualToString:@"POST"]) return RKRequestMethodPOST; else if ([methodName isEqualToString:@"PUT"]) return RKRequestMethodPUT; else if ([methodName isEqualToString:@"DELETE"]) return RKRequestMethodDELETE; else if ([methodName isEqualToString:@"HEAD"]) return RKRequestMethodHEAD; else if ([methodName isEqualToString:@"PATCH"]) return RKRequestMethodPATCH; else if ([methodName isEqualToString:@"OPTIONS"]) return RKRequestMethodOPTIONS; else return RKRequestMethodInvalid; } /** Below is ragel source used to compile those tables. The output was polished / pretty-printed and tweaked from ragel. As the generated code is "hard" to debug, we store the code in http-date.r1 shell% ragel -F1 http-date.rl shell% gcc -o http-date http-date.c shell% ./http-date 'Sun, 06 Nov 1994 08:49:37 GMT' 'Sunday, 06-Nov-94 08:49:37 GMT' 'Sun Nov 6 08:49:37 1994' 'Sat Dec 24 14:34:26 2037' 'Sunday, 06-Nov-94 08:49:37 GMT' 'Sun, 06 Nov 1994 08:49:37 GMT' */ static const char _httpDate_trans_keys[] = { 0, 0, 70, 87, 114, 114, 105, 105, 32, 100, 65, 83, 112, 117, 114, 114, 32, 32, 32, 57, 48, 57, 32, 32, 48, 57, 48, 57, 58, 58, 48, 57, 48, 57, 58, 58, 48, 57, 48, 57, 32, 32, 48, 57, 48, 57, 48, 57, 48, 57, 103, 103, 101, 101, 99, 99, 101, 101, 98, 98, 97, 117, 110, 110, 108, 110, 97, 97, 114, 121, 111, 111, 118, 118, 99, 99, 116, 116, 101, 101, 112, 112, 32, 32, 48, 57, 48, 57, 32, 32, 65, 83, 112, 117, 114, 114, 32, 32, 48, 57, 48, 57, 48, 57, 48, 57, 32, 32, 48, 57, 48, 57, 58, 58, 48, 57, 48, 57, 58, 58, 48, 57, 48, 57, 32, 32, 71, 71, 77, 77, 84, 84, 103, 103, 101, 101, 99, 99, 101, 101, 98, 98, 97, 117, 110, 110, 108, 110, 97, 97, 114, 121, 111, 111, 118, 118, 99, 99, 116, 116, 101, 101, 112, 112, 97, 97, 121, 121, 44, 44, 32, 32, 48, 57, 48, 57, 45, 45, 65, 83, 112, 117, 114, 114, 45, 45, 48, 57, 48, 57, 32, 32, 48, 57, 48, 57, 58, 58, 48, 57, 48, 57, 58, 58, 48, 57, 48, 57, 32, 32, 71, 71, 77, 77, 84, 84, 103, 103, 101, 101, 99, 99, 101, 101, 98, 98, 97, 117, 110, 110, 108, 110, 97, 97, 114, 121, 111, 111, 118, 118, 99, 99, 116, 116, 101, 101, 112, 112, 111, 111, 110, 110, 97, 117, 116, 116, 32, 117, 114, 114, 100, 100, 104, 117, 117, 117, 32, 114, 115, 115, 101, 101, 32, 115, 101, 101, 100, 100, 32, 110, 101, 101, 0, 0, 0, 0, 0, 0, 0 }; static const char _httpDate_key_spans[] = { 0, 18, 1, 1, 69, 19, 6, 1, 1, 26, 10, 1, 10, 10, 1, 10, 10, 1, 10, 10, 1, 10, 10, 10, 10, 1, 1, 1, 1, 1, 21, 1, 3, 1, 8, 1, 1, 1, 1, 1, 1, 1, 10, 10, 1, 19, 6, 1, 1, 10, 10, 10, 10, 1, 10, 10, 1, 10, 10, 1, 10, 10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 21, 1, 3, 1, 8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 10, 10, 1, 19, 6, 1, 1, 10, 10, 1, 10, 10, 1, 10, 10, 1, 10, 10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 21, 1, 3, 1, 8, 1, 1, 1, 1, 1, 1, 1, 1, 21, 1, 86, 1, 1, 14, 1, 83, 1, 1, 84, 1, 1, 79, 1, 0, 0, 0 }; static const short _httpDate_index_offsets[] = { 0, 0, 19, 21, 23, 93, 113, 120, 122, 124, 151, 162, 164, 175, 186, 188, 199, 210, 212, 223, 234, 236, 247, 258, 269, 280, 282, 284, 286, 288, 290, 312, 314, 318, 320, 329, 331, 333, 335, 337, 339, 341, 343, 354, 365, 367, 387, 394, 396, 398, 409, 420, 431, 442, 444, 455, 466, 468, 479, 490, 492, 503, 514, 516, 518, 520, 522, 524, 526, 528, 530, 532, 554, 556, 560, 562, 571, 573, 575, 577, 579, 581, 583, 585, 587, 589, 591, 602, 613, 615, 635, 642, 644, 646, 657, 668, 670, 681, 692, 694, 705, 716, 718, 729, 740, 742, 744, 746, 748, 750, 752, 754, 756, 758, 780, 782, 786, 788, 797, 799, 801, 803, 805, 807, 809, 811, 813, 835, 837, 924, 926, 928, 943, 945, 1029, 1031, 1033, 1118, 1120, 1122, 1202, 1204, 1205, 1206 }; static const unsigned char _httpDate_indicies[] = { 0, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 4, 1, 1, 5, 1, 6, 1, 7, 1, 8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 10, 1, 11, 1, 1, 12, 1, 13, 1, 1, 1, 14, 1, 1, 15, 16, 17, 1, 1, 1, 18, 1, 19, 1, 1, 1, 1, 20, 1, 21, 1, 22, 1, 23, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 1, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 1, 26, 1, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 1, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 1, 29, 1, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 1, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 1, 32, 1, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 1, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 1, 35, 1, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 1, 37, 37, 37, 37, 37, 37, 37, 37, 37, 37, 1, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 1, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 1, 40, 1, 41, 1, 42, 1, 43, 1, 44, 1, 45, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 46, 1, 47, 1, 48, 1, 49, 1, 50, 1, 51, 1, 1, 1, 1, 1, 1, 52, 1, 53, 1, 54, 1, 55, 1, 56, 1, 57, 1, 58, 1, 59, 1, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 1, 61, 61, 61, 61, 61, 61, 61, 61, 61, 61, 1, 62, 1, 63, 1, 1, 64, 1, 65, 1, 1, 1, 66, 1, 1, 67, 68, 69, 1, 1, 1, 70, 1, 71, 1, 1, 1, 1, 72, 1, 73, 1, 74, 1, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 1, 76, 76, 76, 76, 76, 76, 76, 76, 76, 76, 1, 77, 77, 77, 77, 77, 77, 77, 77, 77, 77, 1, 78, 78, 78, 78, 78, 78, 78, 78, 78, 78, 1, 79, 1, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 1, 81, 81, 81, 81, 81, 81, 81, 81, 81, 81, 1, 82, 1, 83, 83, 83, 83, 83, 83, 83, 83, 83, 83, 1, 84, 84, 84, 84, 84, 84, 84, 84, 84, 84, 1, 85, 1, 86, 86, 86, 86, 86, 86, 86, 86, 86, 86, 1, 87, 87, 87, 87, 87, 87, 87, 87, 87, 87, 1, 88, 1, 89, 1, 90, 1, 91, 1, 92, 1, 93, 1, 94, 1, 95, 1, 96, 1, 97, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 98, 1, 99, 1, 100, 1, 101, 1, 102, 1, 103, 1, 1, 1, 1, 1, 1, 104, 1, 105, 1, 106, 1, 107, 1, 108, 1, 109, 1, 110, 1, 111, 1, 112, 1, 113, 1, 114, 1, 115, 115, 115, 115, 115, 115, 115, 115, 115, 115, 1, 116, 116, 116, 116, 116, 116, 116, 116, 116, 116, 1, 117, 1, 118, 1, 1, 119, 1, 120, 1, 1, 1, 121, 1, 1, 122, 123, 124, 1, 1, 1, 125, 1, 126, 1, 1, 1, 1, 127, 1, 128, 1, 129, 1, 130, 130, 130, 130, 130, 130, 130, 130, 130, 130, 1, 131, 131, 131, 131, 131, 131, 131, 131, 131, 131, 1, 132, 1, 133, 133, 133, 133, 133, 133, 133, 133, 133, 133, 1, 134, 134, 134, 134, 134, 134, 134, 134, 134, 134, 1, 135, 1, 136, 136, 136, 136, 136, 136, 136, 136, 136, 136, 1, 137, 137, 137, 137, 137, 137, 137, 137, 137, 137, 1, 138, 1, 139, 139, 139, 139, 139, 139, 139, 139, 139, 139, 1, 140, 140, 140, 140, 140, 140, 140, 140, 140, 140, 1, 141, 1, 142, 1, 143, 1, 144, 1, 145, 1, 146, 1, 147, 1, 148, 1, 149, 1, 150, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 151, 1, 152, 1, 153, 1, 154, 1, 155, 1, 156, 1, 1, 1, 1, 1, 1, 157, 1, 158, 1, 159, 1, 160, 1, 161, 1, 162, 1, 163, 1, 164, 1, 7, 1, 165, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 164, 1, 166, 1, 8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 167, 1, 168, 1, 10, 1, 169, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 170, 1, 171, 1, 8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 172, 1, 168, 1, 173, 1, 8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 168, 1, 174, 1, 175, 1, 8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 176, 1, 172, 1, 1, 1, 1, 0 }; static const unsigned char _httpDate_trans_targs[] = { 2, 0, 124, 126, 131, 137, 3, 4, 5, 41, 82, 6, 26, 28, 30, 33, 35, 37, 39, 7, 25, 8, 9, 10, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 141, 8, 27, 8, 29, 8, 31, 32, 8, 8, 8, 34, 8, 8, 36, 8, 38, 8, 40, 8, 42, 43, 44, 45, 46, 67, 69, 71, 74, 76, 78, 80, 47, 66, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 142, 48, 68, 48, 70, 48, 72, 73, 48, 48, 48, 75, 48, 48, 77, 48, 79, 48, 81, 48, 83, 84, 85, 86, 87, 88, 89, 90, 109, 111, 113, 116, 118, 120, 122, 91, 108, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 143, 92, 110, 92, 112, 92, 114, 115, 92, 92, 92, 117, 92, 92, 119, 92, 121, 92, 123, 92, 125, 127, 128, 129, 130, 132, 135, 133, 134, 136, 138, 139, 140 }; static const char _httpDate_trans_actions[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 2, 2, 0, 3, 3, 0, 4, 4, 0, 5, 5, 0, 6, 6, 6, 6, 7, 0, 8, 0, 9, 0, 0, 10, 11, 12, 0, 13, 14, 0, 15, 0, 16, 0, 17, 0, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 6, 6, 6, 6, 0, 3, 3, 0, 4, 4, 0, 5, 5, 0, 0, 0, 0, 7, 0, 8, 0, 9, 0, 0, 10, 11, 12, 0, 13, 14, 0, 15, 0, 16, 0, 17, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 6, 18, 0, 3, 3, 0, 4, 4, 0, 5, 5, 0, 0, 0, 0, 7, 0, 8, 0, 9, 0, 0, 10, 11, 12, 0, 13, 14, 0, 15, 0, 16, 0, 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; static const char _httpDate_eof_actions[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 19, 20, 21 }; static NSDate *_parseHTTPDate(const char *buf, size_t bufLen) { const char *p = buf, *pe = p + bufLen, *eof = pe; int parsed = 0, cs = 1; NSDate *date = NULL; CFGregorianDate gdate; memset(&gdate, 0, sizeof(CFGregorianDate)); { int _slen, _trans; const char *_keys; const unsigned char *_inds; if(p == pe) { goto _test_eof; } _resume: _keys = _httpDate_trans_keys + (cs << 1); _inds = _httpDate_indicies + _httpDate_index_offsets[cs]; _slen = _httpDate_key_spans[cs]; _trans = _inds[(_slen > 0) && (_keys[0] <= (*p)) && ((*p) <= _keys[1]) ? (*p) - _keys[0] : _slen]; cs = _httpDate_trans_targs[_trans]; if(_httpDate_trans_actions[_trans] == 0) { goto _again; } switch(_httpDate_trans_actions[_trans]) { case 6: gdate.year = gdate.year * 10 + ((*p) - '0'); break; case 18: gdate.year = gdate.year * 10 + ((*p) - '0'); gdate.year += 1900; break; case 10: gdate.month = 1; break; case 9: gdate.month = 2; break; case 13: gdate.month = 3; break; case 1: gdate.month = 4; break; case 14: gdate.month = 5; break; case 12: gdate.month = 6; break; case 11: gdate.month = 7; break; case 7: gdate.month = 8; break; case 17: gdate.month = 9; break; case 16: gdate.month = 10; break; case 15: gdate.month = 11; break; case 8: gdate.month = 12; break; case 2: gdate.day = gdate.day * 10 + ((*p) - '0'); break; case 3: gdate.hour = gdate.hour * 10 + ((*p) - '0'); break; case 4: gdate.minute = gdate.minute * 10 + ((*p) - '0'); break; case 5: gdate.second = gdate.second * 10.0 + ((*p) - '0'); break; } _again: if( cs == 0) { goto _out; } if(++p != pe) { goto _resume; } _test_eof: {} if(p == eof) { switch(_httpDate_eof_actions[cs]) { case 19: parsed = 1; break; case 20: parsed = 1; break; case 21: parsed = 1; break; } } _out: {} } static CFTimeZoneRef gmtTimeZone; static dispatch_once_t onceToken; dispatch_once(&onceToken, ^{ gmtTimeZone = CFTimeZoneCreateWithTimeIntervalFromGMT(NULL, 0.0); }); if(parsed == 1) { date = [NSDate dateWithTimeIntervalSinceReferenceDate:CFGregorianDateGetAbsoluteTime(gdate, gmtTimeZone)]; } return(date); } /* * Parse HTTP Date: http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.3.1 */ NSDate * RKDateFromHTTPDateString(NSString *httpDate) { char stringBuffer[256]; size_t stringLength = (size_t)CFStringGetLength((__bridge CFStringRef)httpDate); const char *cStringPtr = (const char *)CFStringGetCStringPtr((__bridge CFStringRef)httpDate, kCFStringEncodingMacRoman); if(cStringPtr == NULL) { CFIndex usedBytes = 0L, convertedCount = 0L; convertedCount = CFStringGetBytes((__bridge CFStringRef)httpDate, CFRangeMake(0L, (CFIndex)stringLength), kCFStringEncodingUTF8, '?', NO, (UInt8 *)stringBuffer, sizeof(stringBuffer) - 1L, &usedBytes); if(((size_t)convertedCount != stringLength) || (usedBytes < 0L)) { return(NULL); } stringBuffer[usedBytes] = '\0'; cStringPtr = (const char *)stringBuffer; } return(_parseHTTPDate(cStringPtr, stringLength)); } static float const kRKURLCacheLastModFraction = 0.1f; // 10% since Last-Modified suggested by RFC2616 section 13.2.4 static float const kRKURLCacheDefault = 3600.0f; // Default cache expiration delay if none defined (1 hour) /* * This method tries to determine the expiration date based on a response headers dictionary. */ NSDate * RKHTTPCacheExpirationDateFromHeadersWithStatusCode(NSDictionary *headers, NSInteger statusCode) { if (statusCode != 200 && statusCode != 203 && statusCode != 300 && statusCode != 301 && statusCode != 302 && statusCode != 307 && statusCode != 410) { // Uncacheable response status code return nil; } // Check Pragma: no-cache NSString *pragma = [headers objectForKey:@"Pragma"]; if (pragma && [pragma isEqualToString:@"no-cache"]) { // Uncacheable response return nil; } // Define "now" based on the request NSString *date = [headers objectForKey:@"Date"]; // If no Date: header, define now from local clock NSDate *now = date ? RKDateFromHTTPDateString(date) : [NSDate date]; // Look at info from the Cache-Control: max-age=n header NSString *cacheControl = [[headers objectForKey:@"Cache-Control"] lowercaseString]; if (cacheControl) { NSRange foundRange = [cacheControl rangeOfString:@"no-store"]; if (foundRange.length > 0) { // If no-store, the content cannot be cached at all // See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9.2 return nil; } foundRange = [cacheControl rangeOfString:@"no-cache"]; if (foundRange.length > 0) { // If no-cache, we must revalidate with the origin server // See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9.1 return nil; } NSInteger maxAge; foundRange = [cacheControl rangeOfString:@"max-age"]; if (foundRange.length > 0) { NSScanner *cacheControlScanner = [NSScanner scannerWithString:cacheControl]; [cacheControlScanner setScanLocation:foundRange.location + foundRange.length]; [cacheControlScanner scanString:@"=" intoString:nil]; if ([cacheControlScanner scanInteger:&maxAge]) { return maxAge > 0 ? [[NSDate alloc] initWithTimeInterval:maxAge sinceDate:now] : nil; } } } // If not Cache-Control found, look at the Expires header NSString *expires = [headers objectForKey:@"Expires"]; if (expires) { NSTimeInterval expirationInterval = 0; NSDate *expirationDate = RKDateFromHTTPDateString(expires); if (expirationDate) { expirationInterval = [expirationDate timeIntervalSinceDate:now]; } if (expirationInterval > 0) { // Convert remote expiration date to local expiration date return [NSDate dateWithTimeIntervalSinceNow:expirationInterval]; } else { // If the Expires header can't be parsed or is expired, do not cache return nil; } } if (statusCode == 302 || statusCode == 307) { // If not explict cache control defined, do not cache those status return nil; } // If no cache control defined, try some heristic to determine an expiration date NSString *lastModified = [headers objectForKey:@"Last-Modified"]; if (lastModified) { NSTimeInterval age = 0; NSDate *lastModifiedDate = RKDateFromHTTPDateString(lastModified); if (lastModifiedDate) { // Define the age of the document by comparing the Date header with the Last-Modified header age = [now timeIntervalSinceDate:lastModifiedDate]; } return age > 0 ? [NSDate dateWithTimeIntervalSinceNow:(age * kRKURLCacheLastModFraction)] : nil; } // If nothing permitted to define the cache expiration delay nor to restrict its cacheability, use a default cache expiration delay return [[NSDate alloc] initWithTimeInterval:kRKURLCacheDefault sinceDate:now]; } BOOL RKURLIsRelativeToURL(NSURL *URL, NSURL *baseURL) { return [[URL absoluteString] hasPrefix:[baseURL absoluteString]]; } NSString *RKPathAndQueryStringFromURLRelativeToURL(NSURL *URL, NSURL *baseURL) { if (baseURL) { if (! RKURLIsRelativeToURL(URL, baseURL)) return nil; return [[URL absoluteString] substringFromIndex:[[baseURL absoluteString] length]]; } else { // NOTE: [URL relativeString] would return the same value as `absoluteString` if URL is not relative to a baseURL NSString *query = [URL query]; return (query && [query length]) ? [NSString stringWithFormat:@"%@?%@", [URL path], query] : [URL path]; } }