-
-
Notifications
You must be signed in to change notification settings - Fork 24
/
Copy pathGCDAsyncSocket.m
7430 lines (5855 loc) · 195 KB
/
GCDAsyncSocket.m
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
//
// GCDAsyncSocket.m
//
// This class is in the public domain.
// Originally created by Robbie Hanson in Q4 2010.
// Updated and maintained by Deusty LLC and the Apple development community.
//
// https://github.com/robbiehanson/CocoaAsyncSocket
//
#import "GCDAsyncSocket.h"
#if TARGET_OS_IPHONE
#import <CFNetwork/CFNetwork.h>
#endif
#import <arpa/inet.h>
#import <fcntl.h>
#import <ifaddrs.h>
#import <netdb.h>
#import <netinet/in.h>
#import <net/if.h>
#import <sys/socket.h>
#import <sys/types.h>
#import <sys/ioctl.h>
#import <sys/poll.h>
#import <sys/uio.h>
#import <unistd.h>
#if ! __has_feature(objc_arc)
#warning This file must be compiled with ARC. Use -fobjc-arc flag (or convert project to ARC).
// For more information see: https://github.com/robbiehanson/CocoaAsyncSocket/wiki/ARC
#endif
/**
* Does ARC support support GCD objects?
* It does if the minimum deployment target is iOS 6+ or Mac OS X 10.8+
**/
#if TARGET_OS_IPHONE
// Compiling for iOS
#if __IPHONE_OS_VERSION_MIN_REQUIRED >= 60000 // iOS 6.0 or later
#define NEEDS_DISPATCH_RETAIN_RELEASE 0
#else // iOS 5.X or earlier
#define NEEDS_DISPATCH_RETAIN_RELEASE 1
#endif
#else
// Compiling for Mac OS X
#if MAC_OS_X_VERSION_MIN_REQUIRED >= 1080 // Mac OS X 10.8 or later
#define NEEDS_DISPATCH_RETAIN_RELEASE 0
#else
#define NEEDS_DISPATCH_RETAIN_RELEASE 1 // Mac OS X 10.7 or earlier
#endif
#endif
#if 0
// Logging Enabled - See log level below
// Logging uses the CocoaLumberjack framework (which is also GCD based).
// https://github.com/robbiehanson/CocoaLumberjack
//
// It allows us to do a lot of logging without significantly slowing down the code.
#import "DDLog.h"
#define LogAsync YES
#define LogContext 65535
#define LogObjc(flg, frmt, ...) LOG_OBJC_MAYBE(LogAsync, logLevel, flg, LogContext, frmt, ##__VA_ARGS__)
#define LogC(flg, frmt, ...) LOG_C_MAYBE(LogAsync, logLevel, flg, LogContext, frmt, ##__VA_ARGS__)
#define LogError(frmt, ...) LogObjc(LOG_FLAG_ERROR, (@"%@: " frmt), THIS_FILE, ##__VA_ARGS__)
#define LogWarn(frmt, ...) LogObjc(LOG_FLAG_WARN, (@"%@: " frmt), THIS_FILE, ##__VA_ARGS__)
#define LogInfo(frmt, ...) LogObjc(LOG_FLAG_INFO, (@"%@: " frmt), THIS_FILE, ##__VA_ARGS__)
#define LogVerbose(frmt, ...) LogObjc(LOG_FLAG_VERBOSE, (@"%@: " frmt), THIS_FILE, ##__VA_ARGS__)
#define LogCError(frmt, ...) LogC(LOG_FLAG_ERROR, (@"%@: " frmt), THIS_FILE, ##__VA_ARGS__)
#define LogCWarn(frmt, ...) LogC(LOG_FLAG_WARN, (@"%@: " frmt), THIS_FILE, ##__VA_ARGS__)
#define LogCInfo(frmt, ...) LogC(LOG_FLAG_INFO, (@"%@: " frmt), THIS_FILE, ##__VA_ARGS__)
#define LogCVerbose(frmt, ...) LogC(LOG_FLAG_VERBOSE, (@"%@: " frmt), THIS_FILE, ##__VA_ARGS__)
#define LogTrace() LogObjc(LOG_FLAG_VERBOSE, @"%@: %@", THIS_FILE, THIS_METHOD)
#define LogCTrace() LogC(LOG_FLAG_VERBOSE, @"%@: %s", THIS_FILE, __FUNCTION__)
// Log levels : off, error, warn, info, verbose
static const int logLevel = LOG_LEVEL_VERBOSE;
#else
// Logging Disabled
#define LogError(frmt, ...) {}
#define LogWarn(frmt, ...) {}
#define LogInfo(frmt, ...) {}
#define LogVerbose(frmt, ...) {}
#define LogCError(frmt, ...) {}
#define LogCWarn(frmt, ...) {}
#define LogCInfo(frmt, ...) {}
#define LogCVerbose(frmt, ...) {}
#define LogTrace() {}
#define LogCTrace(frmt, ...) {}
#endif
/**
* Seeing a return statements within an inner block
* can sometimes be mistaken for a return point of the enclosing method.
* This makes inline blocks a bit easier to read.
**/
#define return_from_block return
/**
* A socket file descriptor is really just an integer.
* It represents the index of the socket within the kernel.
* This makes invalid file descriptor comparisons easier to read.
**/
#define SOCKET_NULL -1
NSString *const GCDAsyncSocketException = @"GCDAsyncSocketException";
NSString *const GCDAsyncSocketErrorDomain = @"GCDAsyncSocketErrorDomain";
NSString *const GCDAsyncSocketQueueName = @"GCDAsyncSocket";
NSString *const GCDAsyncSocketThreadName = @"GCDAsyncSocket-CFStream";
#if SECURE_TRANSPORT_MAYBE_AVAILABLE
NSString *const GCDAsyncSocketSSLCipherSuites = @"GCDAsyncSocketSSLCipherSuites";
#if TARGET_OS_IPHONE
NSString *const GCDAsyncSocketSSLProtocolVersionMin = @"GCDAsyncSocketSSLProtocolVersionMin";
NSString *const GCDAsyncSocketSSLProtocolVersionMax = @"GCDAsyncSocketSSLProtocolVersionMax";
#else
NSString *const GCDAsyncSocketSSLDiffieHellmanParameters = @"GCDAsyncSocketSSLDiffieHellmanParameters";
#endif
#endif
enum GCDAsyncSocketFlags
{
kSocketStarted = 1 << 0, // If set, socket has been started (accepting/connecting)
kConnected = 1 << 1, // If set, the socket is connected
kForbidReadsWrites = 1 << 2, // If set, no new reads or writes are allowed
kReadsPaused = 1 << 3, // If set, reads are paused due to possible timeout
kWritesPaused = 1 << 4, // If set, writes are paused due to possible timeout
kDisconnectAfterReads = 1 << 5, // If set, disconnect after no more reads are queued
kDisconnectAfterWrites = 1 << 6, // If set, disconnect after no more writes are queued
kSocketCanAcceptBytes = 1 << 7, // If set, we know socket can accept bytes. If unset, it's unknown.
kReadSourceSuspended = 1 << 8, // If set, the read source is suspended
kWriteSourceSuspended = 1 << 9, // If set, the write source is suspended
kQueuedTLS = 1 << 10, // If set, we've queued an upgrade to TLS
kStartingReadTLS = 1 << 11, // If set, we're waiting for TLS negotiation to complete
kStartingWriteTLS = 1 << 12, // If set, we're waiting for TLS negotiation to complete
kSocketSecure = 1 << 13, // If set, socket is using secure communication via SSL/TLS
kSocketHasReadEOF = 1 << 14, // If set, we have read EOF from socket
kReadStreamClosed = 1 << 15, // If set, we've read EOF plus prebuffer has been drained
#if TARGET_OS_IPHONE
kAddedStreamsToRunLoop = 1 << 16, // If set, CFStreams have been added to listener thread
kUsingCFStreamForTLS = 1 << 17, // If set, we're forced to use CFStream instead of SecureTransport
kSecureSocketHasBytesAvailable = 1 << 18, // If set, CFReadStream has notified us of bytes available
#endif
};
enum GCDAsyncSocketConfig
{
kIPv4Disabled = 1 << 0, // If set, IPv4 is disabled
kIPv6Disabled = 1 << 1, // If set, IPv6 is disabled
kPreferIPv6 = 1 << 2, // If set, IPv6 is preferred over IPv4
kAllowHalfDuplexConnection = 1 << 3, // If set, the socket will stay open even if the read stream closes
};
#if TARGET_OS_IPHONE
static NSThread *cfstreamThread; // Used for CFStreams
#endif
@interface GCDAsyncSocket ()
{
uint32_t flags;
uint16_t config;
#if __has_feature(objc_arc_weak)
__weak id delegate;
#else
__unsafe_unretained id delegate;
#endif
dispatch_queue_t delegateQueue;
int socket4FD;
int socket6FD;
int connectIndex;
NSData * connectInterface4;
NSData * connectInterface6;
dispatch_queue_t socketQueue;
dispatch_source_t accept4Source;
dispatch_source_t accept6Source;
dispatch_source_t connectTimer;
dispatch_source_t readSource;
dispatch_source_t writeSource;
dispatch_source_t readTimer;
dispatch_source_t writeTimer;
NSMutableArray *readQueue;
NSMutableArray *writeQueue;
GCDAsyncReadPacket *currentRead;
GCDAsyncWritePacket *currentWrite;
unsigned long socketFDBytesAvailable;
GCDAsyncSocketPreBuffer *preBuffer;
#if TARGET_OS_IPHONE
CFStreamClientContext streamContext;
CFReadStreamRef readStream;
CFWriteStreamRef writeStream;
#endif
#if SECURE_TRANSPORT_MAYBE_AVAILABLE
SSLContextRef sslContext;
GCDAsyncSocketPreBuffer *sslPreBuffer;
size_t sslWriteCachedLength;
OSStatus sslErrCode;
#endif
void *IsOnSocketQueueOrTargetQueueKey;
id userData;
}
// Accepting
- (BOOL)doAccept:(int)socketFD;
// Connecting
- (void)startConnectTimeout:(NSTimeInterval)timeout;
- (void)endConnectTimeout;
- (void)doConnectTimeout;
- (void)lookup:(int)aConnectIndex host:(NSString *)host port:(uint16_t)port;
- (void)lookup:(int)aConnectIndex didSucceedWithAddress4:(NSData *)address4 address6:(NSData *)address6;
- (void)lookup:(int)aConnectIndex didFail:(NSError *)error;
- (BOOL)connectWithAddress4:(NSData *)address4 address6:(NSData *)address6 error:(NSError **)errPtr;
- (void)didConnect:(int)aConnectIndex;
- (void)didNotConnect:(int)aConnectIndex error:(NSError *)error;
// Disconnect
- (void)closeWithError:(NSError *)error;
- (void)maybeClose;
// Errors
- (NSError *)badConfigError:(NSString *)msg;
- (NSError *)badParamError:(NSString *)msg;
- (NSError *)gaiError:(int)gai_error;
- (NSError *)errnoError;
- (NSError *)errnoErrorWithReason:(NSString *)reason;
- (NSError *)connectTimeoutError;
- (NSError *)otherError:(NSString *)msg;
// Diagnostics
- (NSString *)connectedHost4;
- (NSString *)connectedHost6;
- (uint16_t)connectedPort4;
- (uint16_t)connectedPort6;
- (NSString *)localHost4;
- (NSString *)localHost6;
- (uint16_t)localPort4;
- (uint16_t)localPort6;
- (NSString *)connectedHostFromSocket4:(int)socketFD;
- (NSString *)connectedHostFromSocket6:(int)socketFD;
- (uint16_t)connectedPortFromSocket4:(int)socketFD;
- (uint16_t)connectedPortFromSocket6:(int)socketFD;
- (NSString *)localHostFromSocket4:(int)socketFD;
- (NSString *)localHostFromSocket6:(int)socketFD;
- (uint16_t)localPortFromSocket4:(int)socketFD;
- (uint16_t)localPortFromSocket6:(int)socketFD;
// Utilities
- (void)getInterfaceAddress4:(NSMutableData **)addr4Ptr
address6:(NSMutableData **)addr6Ptr
fromDescription:(NSString *)interfaceDescription
port:(uint16_t)port;
- (void)setupReadAndWriteSourcesForNewlyConnectedSocket:(int)socketFD;
- (void)suspendReadSource;
- (void)resumeReadSource;
- (void)suspendWriteSource;
- (void)resumeWriteSource;
// Reading
- (void)maybeDequeueRead;
- (void)flushSSLBuffers;
- (void)doReadData;
- (void)doReadEOF;
- (void)completeCurrentRead;
- (void)endCurrentRead;
- (void)setupReadTimerWithTimeout:(NSTimeInterval)timeout;
- (void)doReadTimeout;
- (void)doReadTimeoutWithExtension:(NSTimeInterval)timeoutExtension;
// Writing
- (void)maybeDequeueWrite;
- (void)doWriteData;
- (void)completeCurrentWrite;
- (void)endCurrentWrite;
- (void)setupWriteTimerWithTimeout:(NSTimeInterval)timeout;
- (void)doWriteTimeout;
- (void)doWriteTimeoutWithExtension:(NSTimeInterval)timeoutExtension;
// Security
- (void)maybeStartTLS;
#if SECURE_TRANSPORT_MAYBE_AVAILABLE
- (void)ssl_startTLS;
- (void)ssl_continueSSLHandshake;
#endif
#if TARGET_OS_IPHONE
- (void)cf_startTLS;
#endif
// CFStream
#if TARGET_OS_IPHONE
+ (void)startCFStreamThreadIfNeeded;
- (BOOL)createReadAndWriteStream;
- (BOOL)registerForStreamCallbacksIncludingReadWrite:(BOOL)includeReadWrite;
- (BOOL)addStreamsToRunLoop;
- (BOOL)openStreams;
- (void)removeStreamsFromRunLoop;
#endif
// Class Methods
+ (NSString *)hostFromSockaddr4:(const struct sockaddr_in *)pSockaddr4;
+ (NSString *)hostFromSockaddr6:(const struct sockaddr_in6 *)pSockaddr6;
+ (uint16_t)portFromSockaddr4:(const struct sockaddr_in *)pSockaddr4;
+ (uint16_t)portFromSockaddr6:(const struct sockaddr_in6 *)pSockaddr6;
@end
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark -
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* A PreBuffer is used when there is more data available on the socket
* than is being requested by current read request.
* In this case we slurp up all data from the socket (to minimize sys calls),
* and store additional yet unread data in a "prebuffer".
*
* The prebuffer is entirely drained before we read from the socket again.
* In other words, a large chunk of data is written is written to the prebuffer.
* The prebuffer is then drained via a series of one or more reads (for subsequent read request(s)).
*
* A ring buffer was once used for this purpose.
* But a ring buffer takes up twice as much memory as needed (double the size for mirroring).
* In fact, it generally takes up more than twice the needed size as everything has to be rounded up to vm_page_size.
* And since the prebuffer is always completely drained after being written to, a full ring buffer isn't needed.
*
* The current design is very simple and straight-forward, while also keeping memory requirements lower.
**/
@interface GCDAsyncSocketPreBuffer : NSObject
{
uint8_t *preBuffer;
size_t preBufferSize;
uint8_t *readPointer;
uint8_t *writePointer;
}
- (id)initWithCapacity:(size_t)numBytes;
- (void)ensureCapacityForWrite:(size_t)numBytes;
- (size_t)availableBytes;
- (uint8_t *)readBuffer;
- (void)getReadBuffer:(uint8_t **)bufferPtr availableBytes:(size_t *)availableBytesPtr;
- (size_t)availableSpace;
- (uint8_t *)writeBuffer;
- (void)getWriteBuffer:(uint8_t **)bufferPtr availableSpace:(size_t *)availableSpacePtr;
- (void)didRead:(size_t)bytesRead;
- (void)didWrite:(size_t)bytesWritten;
- (void)reset;
@end
@implementation GCDAsyncSocketPreBuffer
- (id)initWithCapacity:(size_t)numBytes
{
if ((self = [super init]))
{
preBufferSize = numBytes;
preBuffer = malloc(preBufferSize);
readPointer = preBuffer;
writePointer = preBuffer;
}
return self;
}
- (void)dealloc
{
if (preBuffer)
free(preBuffer);
}
- (void)ensureCapacityForWrite:(size_t)numBytes
{
size_t availableSpace = preBufferSize - (writePointer - readPointer);
if (numBytes > availableSpace)
{
size_t additionalBytes = numBytes - availableSpace;
size_t newPreBufferSize = preBufferSize + additionalBytes;
uint8_t *newPreBuffer = realloc(preBuffer, newPreBufferSize);
size_t readPointerOffset = readPointer - preBuffer;
size_t writePointerOffset = writePointer - preBuffer;
preBuffer = newPreBuffer;
preBufferSize = newPreBufferSize;
readPointer = preBuffer + readPointerOffset;
writePointer = preBuffer + writePointerOffset;
}
}
- (size_t)availableBytes
{
return writePointer - readPointer;
}
- (uint8_t *)readBuffer
{
return readPointer;
}
- (void)getReadBuffer:(uint8_t **)bufferPtr availableBytes:(size_t *)availableBytesPtr
{
if (bufferPtr) *bufferPtr = readPointer;
if (availableBytesPtr) *availableBytesPtr = writePointer - readPointer;
}
- (void)didRead:(size_t)bytesRead
{
readPointer += bytesRead;
if (readPointer == writePointer)
{
// The prebuffer has been drained. Reset pointers.
readPointer = preBuffer;
writePointer = preBuffer;
}
}
- (size_t)availableSpace
{
return preBufferSize - (writePointer - readPointer);
}
- (uint8_t *)writeBuffer
{
return writePointer;
}
- (void)getWriteBuffer:(uint8_t **)bufferPtr availableSpace:(size_t *)availableSpacePtr
{
if (bufferPtr) *bufferPtr = writePointer;
if (availableSpacePtr) *availableSpacePtr = preBufferSize - (writePointer - readPointer);
}
- (void)didWrite:(size_t)bytesWritten
{
writePointer += bytesWritten;
}
- (void)reset
{
readPointer = preBuffer;
writePointer = preBuffer;
}
@end
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark -
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* The GCDAsyncReadPacket encompasses the instructions for any given read.
* The content of a read packet allows the code to determine if we're:
* - reading to a certain length
* - reading to a certain separator
* - or simply reading the first chunk of available data
**/
@interface GCDAsyncReadPacket : NSObject
{
@public
NSMutableData *buffer;
NSUInteger startOffset;
NSUInteger bytesDone;
NSUInteger maxLength;
NSTimeInterval timeout;
NSUInteger readLength;
NSData *term;
BOOL bufferOwner;
NSUInteger originalBufferLength;
long tag;
}
- (id)initWithData:(NSMutableData *)d
startOffset:(NSUInteger)s
maxLength:(NSUInteger)m
timeout:(NSTimeInterval)t
readLength:(NSUInteger)l
terminator:(NSData *)e
tag:(long)i;
- (void)ensureCapacityForAdditionalDataOfLength:(NSUInteger)bytesToRead;
- (NSUInteger)optimalReadLengthWithDefault:(NSUInteger)defaultValue shouldPreBuffer:(BOOL *)shouldPreBufferPtr;
- (NSUInteger)readLengthForNonTermWithHint:(NSUInteger)bytesAvailable;
- (NSUInteger)readLengthForTermWithHint:(NSUInteger)bytesAvailable shouldPreBuffer:(BOOL *)shouldPreBufferPtr;
- (NSUInteger)readLengthForTermWithPreBuffer:(GCDAsyncSocketPreBuffer *)preBuffer found:(BOOL *)foundPtr;
- (NSInteger)searchForTermAfterPreBuffering:(ssize_t)numBytes;
@end
@implementation GCDAsyncReadPacket
- (id)initWithData:(NSMutableData *)d
startOffset:(NSUInteger)s
maxLength:(NSUInteger)m
timeout:(NSTimeInterval)t
readLength:(NSUInteger)l
terminator:(NSData *)e
tag:(long)i
{
if((self = [super init]))
{
bytesDone = 0;
maxLength = m;
timeout = t;
readLength = l;
term = [e copy];
tag = i;
if (d)
{
buffer = d;
startOffset = s;
bufferOwner = NO;
originalBufferLength = [d length];
}
else
{
if (readLength > 0)
buffer = [[NSMutableData alloc] initWithLength:readLength];
else
buffer = [[NSMutableData alloc] initWithLength:0];
startOffset = 0;
bufferOwner = YES;
originalBufferLength = 0;
}
}
return self;
}
/**
* Increases the length of the buffer (if needed) to ensure a read of the given size will fit.
**/
- (void)ensureCapacityForAdditionalDataOfLength:(NSUInteger)bytesToRead
{
NSUInteger buffSize = [buffer length];
NSUInteger buffUsed = startOffset + bytesDone;
NSUInteger buffSpace = buffSize - buffUsed;
if (bytesToRead > buffSpace)
{
NSUInteger buffInc = bytesToRead - buffSpace;
[buffer increaseLengthBy:buffInc];
}
}
/**
* This method is used when we do NOT know how much data is available to be read from the socket.
* This method returns the default value unless it exceeds the specified readLength or maxLength.
*
* Furthermore, the shouldPreBuffer decision is based upon the packet type,
* and whether the returned value would fit in the current buffer without requiring a resize of the buffer.
**/
- (NSUInteger)optimalReadLengthWithDefault:(NSUInteger)defaultValue shouldPreBuffer:(BOOL *)shouldPreBufferPtr
{
NSUInteger result;
if (readLength > 0)
{
// Read a specific length of data
result = MIN(defaultValue, (readLength - bytesDone));
// There is no need to prebuffer since we know exactly how much data we need to read.
// Even if the buffer isn't currently big enough to fit this amount of data,
// it would have to be resized eventually anyway.
if (shouldPreBufferPtr)
*shouldPreBufferPtr = NO;
}
else
{
// Either reading until we find a specified terminator,
// or we're simply reading all available data.
//
// In other words, one of:
//
// - readDataToData packet
// - readDataWithTimeout packet
if (maxLength > 0)
result = MIN(defaultValue, (maxLength - bytesDone));
else
result = defaultValue;
// Since we don't know the size of the read in advance,
// the shouldPreBuffer decision is based upon whether the returned value would fit
// in the current buffer without requiring a resize of the buffer.
//
// This is because, in all likelyhood, the amount read from the socket will be less than the default value.
// Thus we should avoid over-allocating the read buffer when we can simply use the pre-buffer instead.
if (shouldPreBufferPtr)
{
NSUInteger buffSize = [buffer length];
NSUInteger buffUsed = startOffset + bytesDone;
NSUInteger buffSpace = buffSize - buffUsed;
if (buffSpace >= result)
*shouldPreBufferPtr = NO;
else
*shouldPreBufferPtr = YES;
}
}
return result;
}
/**
* For read packets without a set terminator, returns the amount of data
* that can be read without exceeding the readLength or maxLength.
*
* The given parameter indicates the number of bytes estimated to be available on the socket,
* which is taken into consideration during the calculation.
*
* The given hint MUST be greater than zero.
**/
- (NSUInteger)readLengthForNonTermWithHint:(NSUInteger)bytesAvailable
{
NSAssert(term == nil, @"This method does not apply to term reads");
NSAssert(bytesAvailable > 0, @"Invalid parameter: bytesAvailable");
if (readLength > 0)
{
// Read a specific length of data
return MIN(bytesAvailable, (readLength - bytesDone));
// No need to avoid resizing the buffer.
// If the user provided their own buffer,
// and told us to read a certain length of data that exceeds the size of the buffer,
// then it is clear that our code will resize the buffer during the read operation.
//
// This method does not actually do any resizing.
// The resizing will happen elsewhere if needed.
}
else
{
// Read all available data
NSUInteger result = bytesAvailable;
if (maxLength > 0)
{
result = MIN(result, (maxLength - bytesDone));
}
// No need to avoid resizing the buffer.
// If the user provided their own buffer,
// and told us to read all available data without giving us a maxLength,
// then it is clear that our code might resize the buffer during the read operation.
//
// This method does not actually do any resizing.
// The resizing will happen elsewhere if needed.
return result;
}
}
/**
* For read packets with a set terminator, returns the amount of data
* that can be read without exceeding the maxLength.
*
* The given parameter indicates the number of bytes estimated to be available on the socket,
* which is taken into consideration during the calculation.
*
* To optimize memory allocations, mem copies, and mem moves
* the shouldPreBuffer boolean value will indicate if the data should be read into a prebuffer first,
* or if the data can be read directly into the read packet's buffer.
**/
- (NSUInteger)readLengthForTermWithHint:(NSUInteger)bytesAvailable shouldPreBuffer:(BOOL *)shouldPreBufferPtr
{
NSAssert(term != nil, @"This method does not apply to non-term reads");
NSAssert(bytesAvailable > 0, @"Invalid parameter: bytesAvailable");
NSUInteger result = bytesAvailable;
if (maxLength > 0)
{
result = MIN(result, (maxLength - bytesDone));
}
// Should the data be read into the read packet's buffer, or into a pre-buffer first?
//
// One would imagine the preferred option is the faster one.
// So which one is faster?
//
// Reading directly into the packet's buffer requires:
// 1. Possibly resizing packet buffer (malloc/realloc)
// 2. Filling buffer (read)
// 3. Searching for term (memcmp)
// 4. Possibly copying overflow into prebuffer (malloc/realloc, memcpy)
//
// Reading into prebuffer first:
// 1. Possibly resizing prebuffer (malloc/realloc)
// 2. Filling buffer (read)
// 3. Searching for term (memcmp)
// 4. Copying underflow into packet buffer (malloc/realloc, memcpy)
// 5. Removing underflow from prebuffer (memmove)
//
// Comparing the performance of the two we can see that reading
// data into the prebuffer first is slower due to the extra memove.
//
// However:
// The implementation of NSMutableData is open source via core foundation's CFMutableData.
// Decreasing the length of a mutable data object doesn't cause a realloc.
// In other words, the capacity of a mutable data object can grow, but doesn't shrink.
//
// This means the prebuffer will rarely need a realloc.
// The packet buffer, on the other hand, may often need a realloc.
// This is especially true if we are the buffer owner.
// Furthermore, if we are constantly realloc'ing the packet buffer,
// and then moving the overflow into the prebuffer,
// then we're consistently over-allocating memory for each term read.
// And now we get into a bit of a tradeoff between speed and memory utilization.
//
// The end result is that the two perform very similarly.
// And we can answer the original question very simply by another means.
//
// If we can read all the data directly into the packet's buffer without resizing it first,
// then we do so. Otherwise we use the prebuffer.
if (shouldPreBufferPtr)
{
NSUInteger buffSize = [buffer length];
NSUInteger buffUsed = startOffset + bytesDone;
if ((buffSize - buffUsed) >= result)
*shouldPreBufferPtr = NO;
else
*shouldPreBufferPtr = YES;
}
return result;
}
/**
* For read packets with a set terminator,
* returns the amount of data that can be read from the given preBuffer,
* without going over a terminator or the maxLength.
*
* It is assumed the terminator has not already been read.
**/
- (NSUInteger)readLengthForTermWithPreBuffer:(GCDAsyncSocketPreBuffer *)preBuffer found:(BOOL *)foundPtr
{
NSAssert(term != nil, @"This method does not apply to non-term reads");
NSAssert([preBuffer availableBytes] > 0, @"Invoked with empty pre buffer!");
// We know that the terminator, as a whole, doesn't exist in our own buffer.
// But it is possible that a _portion_ of it exists in our buffer.
// So we're going to look for the terminator starting with a portion of our own buffer.
//
// Example:
//
// term length = 3 bytes
// bytesDone = 5 bytes
// preBuffer length = 5 bytes
//
// If we append the preBuffer to our buffer,
// it would look like this:
//
// ---------------------
// |B|B|B|B|B|P|P|P|P|P|
// ---------------------
//
// So we start our search here:
//
// ---------------------
// |B|B|B|B|B|P|P|P|P|P|
// -------^-^-^---------
//
// And move forwards...
//
// ---------------------
// |B|B|B|B|B|P|P|P|P|P|
// ---------^-^-^-------
//
// Until we find the terminator or reach the end.
//
// ---------------------
// |B|B|B|B|B|P|P|P|P|P|
// ---------------^-^-^-
BOOL found = NO;
NSUInteger termLength = [term length];
NSUInteger preBufferLength = [preBuffer availableBytes];
if ((bytesDone + preBufferLength) < termLength)
{
// Not enough data for a full term sequence yet
return preBufferLength;
}
NSUInteger maxPreBufferLength;
if (maxLength > 0) {
maxPreBufferLength = MIN(preBufferLength, (maxLength - bytesDone));
// Note: maxLength >= termLength
}
else {
maxPreBufferLength = preBufferLength;
}
uint8_t seq[termLength];
const void *termBuf = [term bytes];
NSUInteger bufLen = MIN(bytesDone, (termLength - 1));
uint8_t *buf = (uint8_t *)[buffer mutableBytes] + startOffset + bytesDone - bufLen;
NSUInteger preLen = termLength - bufLen;
const uint8_t *pre = [preBuffer readBuffer];
NSUInteger loopCount = bufLen + maxPreBufferLength - termLength + 1; // Plus one. See example above.
NSUInteger result = maxPreBufferLength;
NSUInteger i;
for (i = 0; i < loopCount; i++)
{
if (bufLen > 0)
{
// Combining bytes from buffer and preBuffer
memcpy(seq, buf, bufLen);
memcpy(seq + bufLen, pre, preLen);
if (memcmp(seq, termBuf, termLength) == 0)
{
result = preLen;
found = YES;
break;
}
buf++;
bufLen--;
preLen++;
}
else
{
// Comparing directly from preBuffer
if (memcmp(pre, termBuf, termLength) == 0)
{
NSUInteger preOffset = pre - [preBuffer readBuffer]; // pointer arithmetic
result = preOffset + termLength;
found = YES;
break;
}
pre++;
}
}
// There is no need to avoid resizing the buffer in this particular situation.
if (foundPtr) *foundPtr = found;
return result;
}
/**
* For read packets with a set terminator, scans the packet buffer for the term.
* It is assumed the terminator had not been fully read prior to the new bytes.
*
* If the term is found, the number of excess bytes after the term are returned.
* If the term is not found, this method will return -1.
*
* Note: A return value of zero means the term was found at the very end.
*
* Prerequisites:
* The given number of bytes have been added to the end of our buffer.
* Our bytesDone variable has NOT been changed due to the prebuffered bytes.
**/
- (NSInteger)searchForTermAfterPreBuffering:(ssize_t)numBytes
{
NSAssert(term != nil, @"This method does not apply to non-term reads");
// The implementation of this method is very similar to the above method.
// See the above method for a discussion of the algorithm used here.
uint8_t *buff = [buffer mutableBytes];
NSUInteger buffLength = bytesDone + numBytes;
const void *termBuff = [term bytes];
NSUInteger termLength = [term length];
// Note: We are dealing with unsigned integers,
// so make sure the math doesn't go below zero.
NSUInteger i = ((buffLength - numBytes) >= termLength) ? (buffLength - numBytes - termLength + 1) : 0;
while (i + termLength <= buffLength)
{
uint8_t *subBuffer = buff + startOffset + i;
if (memcmp(subBuffer, termBuff, termLength) == 0)
{
return buffLength - (i + termLength);
}
i++;
}
return -1;
}
@end
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark -
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* The GCDAsyncWritePacket encompasses the instructions for any given write.
**/
@interface GCDAsyncWritePacket : NSObject
{
@public
NSData *buffer;
NSUInteger bytesDone;
long tag;
NSTimeInterval timeout;
}
- (id)initWithData:(NSData *)d timeout:(NSTimeInterval)t tag:(long)i;
@end
@implementation GCDAsyncWritePacket
- (id)initWithData:(NSData *)d timeout:(NSTimeInterval)t tag:(long)i
{
if((self = [super init]))
{
buffer = d; // Retain not copy. For performance as documented in header file.
bytesDone = 0;
timeout = t;
tag = i;
}
return self;
}
@end
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark -
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**