forked from llSourcell/Cryptokitties
-
Notifications
You must be signed in to change notification settings - Fork 0
/
CryptoKittiesCore.sol
2010 lines (1686 loc) · 78.2 KB
/
CryptoKittiesCore.sol
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
// CryptoKitties Source code
pragma solidity ^0.4.11;
/**
* @title Ownable
* @dev The Ownable contract has an owner address, and provides basic authorization control
* functions, this simplifies the implementation of "user permissions".
*/
contract Ownable {
address public owner;
/**
* @dev The Ownable constructor sets the original `owner` of the contract to the sender
* account.
*/
function Ownable() {
owner = msg.sender;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(msg.sender == owner);
_;
}
/**
* @dev Allows the current owner to transfer control of the contract to a newOwner.
* @param newOwner The address to transfer ownership to.
*/
function transferOwnership(address newOwner) onlyOwner {
if (newOwner != address(0)) {
owner = newOwner;
}
}
}
/// @title Interface for contracts conforming to ERC-721: Non-Fungible Tokens
/// @author Dieter Shirley <[email protected]> (https://github.com/dete)
contract ERC721 {
// Required methods
function totalSupply() public view returns (uint256 total);
function balanceOf(address _owner) public view returns (uint256 balance);
function ownerOf(uint256 _tokenId) external view returns (address owner);
function approve(address _to, uint256 _tokenId) external;
function transfer(address _to, uint256 _tokenId) external;
function transferFrom(address _from, address _to, uint256 _tokenId) external;
// Events
event Transfer(address from, address to, uint256 tokenId);
event Approval(address owner, address approved, uint256 tokenId);
// Optional
// function name() public view returns (string name);
// function symbol() public view returns (string symbol);
// function tokensOfOwner(address _owner) external view returns (uint256[] tokenIds);
// function tokenMetadata(uint256 _tokenId, string _preferredTransport) public view returns (string infoUrl);
// ERC-165 Compatibility (https://github.com/ethereum/EIPs/issues/165)
function supportsInterface(bytes4 _interfaceID) external view returns (bool);
}
// // Auction wrapper functions
// Auction wrapper functions
/// @title SEKRETOOOO
contract GeneScienceInterface {
/// @dev simply a boolean to indicate this is the contract we expect to be
function isGeneScience() public pure returns (bool);
/// @dev given genes of kitten 1 & 2, return a genetic combination - may have a random factor
/// @param genes1 genes of mom
/// @param genes2 genes of sire
/// @return the genes that are supposed to be passed down the child
function mixGenes(uint256 genes1, uint256 genes2, uint256 targetBlock) public returns (uint256);
}
/// @title A facet of KittyCore that manages special access privileges.
/// @author Axiom Zen (https://www.axiomzen.co)
/// @dev See the KittyCore contract documentation to understand how the various contract facets are arranged.
contract KittyAccessControl {
// This facet controls access control for CryptoKitties. There are four roles managed here:
//
// - The CEO: The CEO can reassign other roles and change the addresses of our dependent smart
// contracts. It is also the only role that can unpause the smart contract. It is initially
// set to the address that created the smart contract in the KittyCore constructor.
//
// - The CFO: The CFO can withdraw funds from KittyCore and its auction contracts.
//
// - The COO: The COO can release gen0 kitties to auction, and mint promo cats.
//
// It should be noted that these roles are distinct without overlap in their access abilities, the
// abilities listed for each role above are exhaustive. In particular, while the CEO can assign any
// address to any role, the CEO address itself doesn't have the ability to act in those roles. This
// restriction is intentional so that we aren't tempted to use the CEO address frequently out of
// convenience. The less we use an address, the less likely it is that we somehow compromise the
// account.
/// @dev Emited when contract is upgraded - See README.md for updgrade plan
event ContractUpgrade(address newContract);
// The addresses of the accounts (or contracts) that can execute actions within each roles.
address public ceoAddress;
address public cfoAddress;
address public cooAddress;
// @dev Keeps track whether the contract is paused. When that is true, most actions are blocked
bool public paused = false;
/// @dev Access modifier for CEO-only functionality
modifier onlyCEO() {
require(msg.sender == ceoAddress);
_;
}
/// @dev Access modifier for CFO-only functionality
modifier onlyCFO() {
require(msg.sender == cfoAddress);
_;
}
/// @dev Access modifier for COO-only functionality
modifier onlyCOO() {
require(msg.sender == cooAddress);
_;
}
modifier onlyCLevel() {
require(
msg.sender == cooAddress ||
msg.sender == ceoAddress ||
msg.sender == cfoAddress
);
_;
}
/// @dev Assigns a new address to act as the CEO. Only available to the current CEO.
/// @param _newCEO The address of the new CEO
function setCEO(address _newCEO) external onlyCEO {
require(_newCEO != address(0));
ceoAddress = _newCEO;
}
/// @dev Assigns a new address to act as the CFO. Only available to the current CEO.
/// @param _newCFO The address of the new CFO
function setCFO(address _newCFO) external onlyCEO {
require(_newCFO != address(0));
cfoAddress = _newCFO;
}
/// @dev Assigns a new address to act as the COO. Only available to the current CEO.
/// @param _newCOO The address of the new COO
function setCOO(address _newCOO) external onlyCEO {
require(_newCOO != address(0));
cooAddress = _newCOO;
}
/*** Pausable functionality adapted from OpenZeppelin ***/
/// @dev Modifier to allow actions only when the contract IS NOT paused
modifier whenNotPaused() {
require(!paused);
_;
}
/// @dev Modifier to allow actions only when the contract IS paused
modifier whenPaused {
require(paused);
_;
}
/// @dev Called by any "C-level" role to pause the contract. Used only when
/// a bug or exploit is detected and we need to limit damage.
function pause() external onlyCLevel whenNotPaused {
paused = true;
}
/// @dev Unpauses the smart contract. Can only be called by the CEO, since
/// one reason we may pause the contract is when CFO or COO accounts are
/// compromised.
/// @notice This is public rather than external so it can be called by
/// derived contracts.
function unpause() public onlyCEO whenPaused {
// can't unpause if contract was upgraded
paused = false;
}
}
/// @title Base contract for CryptoKitties. Holds all common structs, events and base variables.
/// @author Axiom Zen (https://www.axiomzen.co)
/// @dev See the KittyCore contract documentation to understand how the various contract facets are arranged.
contract KittyBase is KittyAccessControl {
/*** EVENTS ***/
/// @dev The Birth event is fired whenever a new kitten comes into existence. This obviously
/// includes any time a cat is created through the giveBirth method, but it is also called
/// when a new gen0 cat is created.
event Birth(address owner, uint256 kittyId, uint256 matronId, uint256 sireId, uint256 genes);
/// @dev Transfer event as defined in current draft of ERC721. Emitted every time a kitten
/// ownership is assigned, including births.
event Transfer(address from, address to, uint256 tokenId);
/*** DATA TYPES ***/
/// @dev The main Kitty struct. Every cat in CryptoKitties is represented by a copy
/// of this structure, so great care was taken to ensure that it fits neatly into
/// exactly two 256-bit words. Note that the order of the members in this structure
/// is important because of the byte-packing rules used by Ethereum.
/// Ref: http://solidity.readthedocs.io/en/develop/miscellaneous.html
struct Kitty {
// The Kitty's genetic code is packed into these 256-bits, the format is
// sooper-sekret! A cat's genes never change.
uint256 genes;
// The timestamp from the block when this cat came into existence.
uint64 birthTime;
// The minimum timestamp after which this cat can engage in breeding
// activities again. This same timestamp is used for the pregnancy
// timer (for matrons) as well as the siring cooldown.
uint64 cooldownEndBlock;
// The ID of the parents of this kitty, set to 0 for gen0 cats.
// Note that using 32-bit unsigned integers limits us to a "mere"
// 4 billion cats. This number might seem small until you realize
// that Ethereum currently has a limit of about 500 million
// transactions per year! So, this definitely won't be a problem
// for several years (even as Ethereum learns to scale).
uint32 matronId;
uint32 sireId;
// Set to the ID of the sire cat for matrons that are pregnant,
// zero otherwise. A non-zero value here is how we know a cat
// is pregnant. Used to retrieve the genetic material for the new
// kitten when the birth transpires.
uint32 siringWithId;
// Set to the index in the cooldown array (see below) that represents
// the current cooldown duration for this Kitty. This starts at zero
// for gen0 cats, and is initialized to floor(generation/2) for others.
// Incremented by one for each successful breeding action, regardless
// of whether this cat is acting as matron or sire.
uint16 cooldownIndex;
// The "generation number" of this cat. Cats minted by the CK contract
// for sale are called "gen0" and have a generation number of 0. The
// generation number of all other cats is the larger of the two generation
// numbers of their parents, plus one.
// (i.e. max(matron.generation, sire.generation) + 1)
uint16 generation;
}
/*** CONSTANTS ***/
/// @dev A lookup table indicating the cooldown duration after any successful
/// breeding action, called "pregnancy time" for matrons and "siring cooldown"
/// for sires. Designed such that the cooldown roughly doubles each time a cat
/// is bred, encouraging owners not to just keep breeding the same cat over
/// and over again. Caps out at one week (a cat can breed an unbounded number
/// of times, and the maximum cooldown is always seven days).
uint32[14] public cooldowns = [
uint32(1 minutes),
uint32(2 minutes),
uint32(5 minutes),
uint32(10 minutes),
uint32(30 minutes),
uint32(1 hours),
uint32(2 hours),
uint32(4 hours),
uint32(8 hours),
uint32(16 hours),
uint32(1 days),
uint32(2 days),
uint32(4 days),
uint32(7 days)
];
// An approximation of currently how many seconds are in between blocks.
uint256 public secondsPerBlock = 15;
/*** STORAGE ***/
/// @dev An array containing the Kitty struct for all Kitties in existence. The ID
/// of each cat is actually an index into this array. Note that ID 0 is a negacat,
/// the unKitty, the mythical beast that is the parent of all gen0 cats. A bizarre
/// creature that is both matron and sire... to itself! Has an invalid genetic code.
/// In other words, cat ID 0 is invalid... ;-)
Kitty[] kitties;
/// @dev A mapping from cat IDs to the address that owns them. All cats have
/// some valid owner address, even gen0 cats are created with a non-zero owner.
mapping (uint256 => address) public kittyIndexToOwner;
// @dev A mapping from owner address to count of tokens that address owns.
// Used internally inside balanceOf() to resolve ownership count.
mapping (address => uint256) ownershipTokenCount;
/// @dev A mapping from KittyIDs to an address that has been approved to call
/// transferFrom(). Each Kitty can only have one approved address for transfer
/// at any time. A zero value means no approval is outstanding.
mapping (uint256 => address) public kittyIndexToApproved;
/// @dev A mapping from KittyIDs to an address that has been approved to use
/// this Kitty for siring via breedWith(). Each Kitty can only have one approved
/// address for siring at any time. A zero value means no approval is outstanding.
mapping (uint256 => address) public sireAllowedToAddress;
/// @dev The address of the ClockAuction contract that handles sales of Kitties. This
/// same contract handles both peer-to-peer sales as well as the gen0 sales which are
/// initiated every 15 minutes.
SaleClockAuction public saleAuction;
/// @dev The address of a custom ClockAuction subclassed contract that handles siring
/// auctions. Needs to be separate from saleAuction because the actions taken on success
/// after a sales and siring auction are quite different.
SiringClockAuction public siringAuction;
/// @dev Assigns ownership of a specific Kitty to an address.
function _transfer(address _from, address _to, uint256 _tokenId) internal {
// Since the number of kittens is capped to 2^32 we can't overflow this
ownershipTokenCount[_to]++;
// transfer ownership
kittyIndexToOwner[_tokenId] = _to;
// When creating new kittens _from is 0x0, but we can't account that address.
if (_from != address(0)) {
ownershipTokenCount[_from]--;
// once the kitten is transferred also clear sire allowances
delete sireAllowedToAddress[_tokenId];
// clear any previously approved ownership exchange
delete kittyIndexToApproved[_tokenId];
}
// Emit the transfer event.
Transfer(_from, _to, _tokenId);
}
/// @dev An internal method that creates a new kitty and stores it. This
/// method doesn't do any checking and should only be called when the
/// input data is known to be valid. Will generate both a Birth event
/// and a Transfer event.
/// @param _matronId The kitty ID of the matron of this cat (zero for gen0)
/// @param _sireId The kitty ID of the sire of this cat (zero for gen0)
/// @param _generation The generation number of this cat, must be computed by caller.
/// @param _genes The kitty's genetic code.
/// @param _owner The inital owner of this cat, must be non-zero (except for the unKitty, ID 0)
function _createKitty(
uint256 _matronId,
uint256 _sireId,
uint256 _generation,
uint256 _genes,
address _owner
)
internal
returns (uint)
{
// These requires are not strictly necessary, our calling code should make
// sure that these conditions are never broken. However! _createKitty() is already
// an expensive call (for storage), and it doesn't hurt to be especially careful
// to ensure our data structures are always valid.
require(_matronId == uint256(uint32(_matronId)));
require(_sireId == uint256(uint32(_sireId)));
require(_generation == uint256(uint16(_generation)));
// New kitty starts with the same cooldown as parent gen/2
uint16 cooldownIndex = uint16(_generation / 2);
if (cooldownIndex > 13) {
cooldownIndex = 13;
}
Kitty memory _kitty = Kitty({
genes: _genes,
birthTime: uint64(now),
cooldownEndBlock: 0,
matronId: uint32(_matronId),
sireId: uint32(_sireId),
siringWithId: 0,
cooldownIndex: cooldownIndex,
generation: uint16(_generation)
});
uint256 newKittenId = kitties.push(_kitty) - 1;
// It's probably never going to happen, 4 billion cats is A LOT, but
// let's just be 100% sure we never let this happen.
require(newKittenId == uint256(uint32(newKittenId)));
// emit the birth event
Birth(
_owner,
newKittenId,
uint256(_kitty.matronId),
uint256(_kitty.sireId),
_kitty.genes
);
// This will assign ownership, and also emit the Transfer event as
// per ERC721 draft
_transfer(0, _owner, newKittenId);
return newKittenId;
}
// Any C-level can fix how many seconds per blocks are currently observed.
function setSecondsPerBlock(uint256 secs) external onlyCLevel {
require(secs < cooldowns[0]);
secondsPerBlock = secs;
}
}
/// @title The external contract that is responsible for generating metadata for the kitties,
/// it has one function that will return the data as bytes.
contract ERC721Metadata {
/// @dev Given a token Id, returns a byte array that is supposed to be converted into string.
function getMetadata(uint256 _tokenId, string) public view returns (bytes32[4] buffer, uint256 count) {
if (_tokenId == 1) {
buffer[0] = "Hello World! :D";
count = 15;
} else if (_tokenId == 2) {
buffer[0] = "I would definitely choose a medi";
buffer[1] = "um length string.";
count = 49;
} else if (_tokenId == 3) {
buffer[0] = "Lorem ipsum dolor sit amet, mi e";
buffer[1] = "st accumsan dapibus augue lorem,";
buffer[2] = " tristique vestibulum id, libero";
buffer[3] = " suscipit varius sapien aliquam.";
count = 128;
}
}
}
/// @title The facet of the CryptoKitties core contract that manages ownership, ERC-721 (draft) compliant.
/// @author Axiom Zen (https://www.axiomzen.co)
/// @dev Ref: https://github.com/ethereum/EIPs/issues/721
/// See the KittyCore contract documentation to understand how the various contract facets are arranged.
contract KittyOwnership is KittyBase, ERC721 {
/// @notice Name and symbol of the non fungible token, as defined in ERC721.
string public constant name = "CryptoKitties";
string public constant symbol = "CK";
// The contract that will return kitty metadata
ERC721Metadata public erc721Metadata;
bytes4 constant InterfaceSignature_ERC165 =
bytes4(keccak256('supportsInterface(bytes4)'));
bytes4 constant InterfaceSignature_ERC721 =
bytes4(keccak256('name()')) ^
bytes4(keccak256('symbol()')) ^
bytes4(keccak256('totalSupply()')) ^
bytes4(keccak256('balanceOf(address)')) ^
bytes4(keccak256('ownerOf(uint256)')) ^
bytes4(keccak256('approve(address,uint256)')) ^
bytes4(keccak256('transfer(address,uint256)')) ^
bytes4(keccak256('transferFrom(address,address,uint256)')) ^
bytes4(keccak256('tokensOfOwner(address)')) ^
bytes4(keccak256('tokenMetadata(uint256,string)'));
/// @notice Introspection interface as per ERC-165 (https://github.com/ethereum/EIPs/issues/165).
/// Returns true for any standardized interfaces implemented by this contract. We implement
/// ERC-165 (obviously!) and ERC-721.
function supportsInterface(bytes4 _interfaceID) external view returns (bool)
{
// DEBUG ONLY
//require((InterfaceSignature_ERC165 == 0x01ffc9a7) && (InterfaceSignature_ERC721 == 0x9a20483d));
return ((_interfaceID == InterfaceSignature_ERC165) || (_interfaceID == InterfaceSignature_ERC721));
}
/// @dev Set the address of the sibling contract that tracks metadata.
/// CEO only.
function setMetadataAddress(address _contractAddress) public onlyCEO {
erc721Metadata = ERC721Metadata(_contractAddress);
}
// Internal utility functions: These functions all assume that their input arguments
// are valid. We leave it to public methods to sanitize their inputs and follow
// the required logic.
/// @dev Checks if a given address is the current owner of a particular Kitty.
/// @param _claimant the address we are validating against.
/// @param _tokenId kitten id, only valid when > 0
function _owns(address _claimant, uint256 _tokenId) internal view returns (bool) {
return kittyIndexToOwner[_tokenId] == _claimant;
}
/// @dev Checks if a given address currently has transferApproval for a particular Kitty.
/// @param _claimant the address we are confirming kitten is approved for.
/// @param _tokenId kitten id, only valid when > 0
function _approvedFor(address _claimant, uint256 _tokenId) internal view returns (bool) {
return kittyIndexToApproved[_tokenId] == _claimant;
}
/// @dev Marks an address as being approved for transferFrom(), overwriting any previous
/// approval. Setting _approved to address(0) clears all transfer approval.
/// NOTE: _approve() does NOT send the Approval event. This is intentional because
/// _approve() and transferFrom() are used together for putting Kitties on auction, and
/// there is no value in spamming the log with Approval events in that case.
function _approve(uint256 _tokenId, address _approved) internal {
kittyIndexToApproved[_tokenId] = _approved;
}
/// @notice Returns the number of Kitties owned by a specific address.
/// @param _owner The owner address to check.
/// @dev Required for ERC-721 compliance
function balanceOf(address _owner) public view returns (uint256 count) {
return ownershipTokenCount[_owner];
}
/// @notice Transfers a Kitty to another address. If transferring to a smart
/// contract be VERY CAREFUL to ensure that it is aware of ERC-721 (or
/// CryptoKitties specifically) or your Kitty may be lost forever. Seriously.
/// @param _to The address of the recipient, can be a user or contract.
/// @param _tokenId The ID of the Kitty to transfer.
/// @dev Required for ERC-721 compliance.
function transfer(
address _to,
uint256 _tokenId
)
external
whenNotPaused
{
// Safety check to prevent against an unexpected 0x0 default.
require(_to != address(0));
// Disallow transfers to this contract to prevent accidental misuse.
// The contract should never own any kitties (except very briefly
// after a gen0 cat is created and before it goes on auction).
require(_to != address(this));
// Disallow transfers to the auction contracts to prevent accidental
// misuse. Auction contracts should only take ownership of kitties
// through the allow + transferFrom flow.
require(_to != address(saleAuction));
require(_to != address(siringAuction));
// You can only send your own cat.
require(_owns(msg.sender, _tokenId));
// Reassign ownership, clear pending approvals, emit Transfer event.
_transfer(msg.sender, _to, _tokenId);
}
/// @notice Grant another address the right to transfer a specific Kitty via
/// transferFrom(). This is the preferred flow for transfering NFTs to contracts.
/// @param _to The address to be granted transfer approval. Pass address(0) to
/// clear all approvals.
/// @param _tokenId The ID of the Kitty that can be transferred if this call succeeds.
/// @dev Required for ERC-721 compliance.
function approve(
address _to,
uint256 _tokenId
)
external
whenNotPaused
{
// Only an owner can grant transfer approval.
require(_owns(msg.sender, _tokenId));
// Register the approval (replacing any previous approval).
_approve(_tokenId, _to);
// Emit approval event.
Approval(msg.sender, _to, _tokenId);
}
/// @notice Transfer a Kitty owned by another address, for which the calling address
/// has previously been granted transfer approval by the owner.
/// @param _from The address that owns the Kitty to be transfered.
/// @param _to The address that should take ownership of the Kitty. Can be any address,
/// including the caller.
/// @param _tokenId The ID of the Kitty to be transferred.
/// @dev Required for ERC-721 compliance.
function transferFrom(
address _from,
address _to,
uint256 _tokenId
)
external
whenNotPaused
{
// Safety check to prevent against an unexpected 0x0 default.
require(_to != address(0));
// Disallow transfers to this contract to prevent accidental misuse.
// The contract should never own any kitties (except very briefly
// after a gen0 cat is created and before it goes on auction).
require(_to != address(this));
// Check for approval and valid ownership
require(_approvedFor(msg.sender, _tokenId));
require(_owns(_from, _tokenId));
// Reassign ownership (also clears pending approvals and emits Transfer event).
_transfer(_from, _to, _tokenId);
}
/// @notice Returns the total number of Kitties currently in existence.
/// @dev Required for ERC-721 compliance.
function totalSupply() public view returns (uint) {
return kitties.length - 1;
}
/// @notice Returns the address currently assigned ownership of a given Kitty.
/// @dev Required for ERC-721 compliance.
function ownerOf(uint256 _tokenId)
external
view
returns (address owner)
{
owner = kittyIndexToOwner[_tokenId];
require(owner != address(0));
}
/// @notice Returns a list of all Kitty IDs assigned to an address.
/// @param _owner The owner whose Kitties we are interested in.
/// @dev This method MUST NEVER be called by smart contract code. First, it's fairly
/// expensive (it walks the entire Kitty array looking for cats belonging to owner),
/// but it also returns a dynamic array, which is only supported for web3 calls, and
/// not contract-to-contract calls.
function tokensOfOwner(address _owner) external view returns(uint256[] ownerTokens) {
uint256 tokenCount = balanceOf(_owner);
if (tokenCount == 0) {
// Return an empty array
return new uint256[](0);
} else {
uint256[] memory result = new uint256[](tokenCount);
uint256 totalCats = totalSupply();
uint256 resultIndex = 0;
// We count on the fact that all cats have IDs starting at 1 and increasing
// sequentially up to the totalCat count.
uint256 catId;
for (catId = 1; catId <= totalCats; catId++) {
if (kittyIndexToOwner[catId] == _owner) {
result[resultIndex] = catId;
resultIndex++;
}
}
return result;
}
}
/// @dev Adapted from memcpy() by @arachnid (Nick Johnson <[email protected]>)
/// This method is licenced under the Apache License.
/// Ref: https://github.com/Arachnid/solidity-stringutils/blob/2f6ca9accb48ae14c66f1437ec50ed19a0616f78/strings.sol
function _memcpy(uint _dest, uint _src, uint _len) private view {
// Copy word-length chunks while possible
for(; _len >= 32; _len -= 32) {
assembly {
mstore(_dest, mload(_src))
}
_dest += 32;
_src += 32;
}
// Copy remaining bytes
uint256 mask = 256 ** (32 - _len) - 1;
assembly {
let srcpart := and(mload(_src), not(mask))
let destpart := and(mload(_dest), mask)
mstore(_dest, or(destpart, srcpart))
}
}
/// @dev Adapted from toString(slice) by @arachnid (Nick Johnson <[email protected]>)
/// This method is licenced under the Apache License.
/// Ref: https://github.com/Arachnid/solidity-stringutils/blob/2f6ca9accb48ae14c66f1437ec50ed19a0616f78/strings.sol
function _toString(bytes32[4] _rawBytes, uint256 _stringLength) private view returns (string) {
var outputString = new string(_stringLength);
uint256 outputPtr;
uint256 bytesPtr;
assembly {
outputPtr := add(outputString, 32)
bytesPtr := _rawBytes
}
_memcpy(outputPtr, bytesPtr, _stringLength);
return outputString;
}
/// @notice Returns a URI pointing to a metadata package for this token conforming to
/// ERC-721 (https://github.com/ethereum/EIPs/issues/721)
/// @param _tokenId The ID number of the Kitty whose metadata should be returned.
function tokenMetadata(uint256 _tokenId, string _preferredTransport) external view returns (string infoUrl) {
require(erc721Metadata != address(0));
bytes32[4] memory buffer;
uint256 count;
(buffer, count) = erc721Metadata.getMetadata(_tokenId, _preferredTransport);
return _toString(buffer, count);
}
}
/// @title A facet of KittyCore that manages Kitty siring, gestation, and birth.
/// @author Axiom Zen (https://www.axiomzen.co)
/// @dev See the KittyCore contract documentation to understand how the various contract facets are arranged.
contract KittyBreeding is KittyOwnership {
/// @dev The Pregnant event is fired when two cats successfully breed and the pregnancy
/// timer begins for the matron.
event Pregnant(address owner, uint256 matronId, uint256 sireId, uint256 cooldownEndBlock);
/// @notice The minimum payment required to use breedWithAuto(). This fee goes towards
/// the gas cost paid by whatever calls giveBirth(), and can be dynamically updated by
/// the COO role as the gas price changes.
uint256 public autoBirthFee = 2 finney;
// Keeps track of number of pregnant kitties.
uint256 public pregnantKitties;
/// @dev The address of the sibling contract that is used to implement the sooper-sekret
/// genetic combination algorithm.
GeneScienceInterface public geneScience;
/// @dev Update the address of the genetic contract, can only be called by the CEO.
/// @param _address An address of a GeneScience contract instance to be used from this point forward.
function setGeneScienceAddress(address _address) external onlyCEO {
GeneScienceInterface candidateContract = GeneScienceInterface(_address);
// NOTE: verify that a contract is what we expect - https://github.com/Lunyr/crowdsale-contracts/blob/cfadd15986c30521d8ba7d5b6f57b4fefcc7ac38/contracts/LunyrToken.sol#L117
require(candidateContract.isGeneScience());
// Set the new contract address
geneScience = candidateContract;
}
/// @dev Checks that a given kitten is able to breed. Requires that the
/// current cooldown is finished (for sires) and also checks that there is
/// no pending pregnancy.
function _isReadyToBreed(Kitty _kit) internal view returns (bool) {
// In addition to checking the cooldownEndBlock, we also need to check to see if
// the cat has a pending birth; there can be some period of time between the end
// of the pregnacy timer and the birth event.
return (_kit.siringWithId == 0) && (_kit.cooldownEndBlock <= uint64(block.number));
}
/// @dev Check if a sire has authorized breeding with this matron. True if both sire
/// and matron have the same owner, or if the sire has given siring permission to
/// the matron's owner (via approveSiring()).
function _isSiringPermitted(uint256 _sireId, uint256 _matronId) internal view returns (bool) {
address matronOwner = kittyIndexToOwner[_matronId];
address sireOwner = kittyIndexToOwner[_sireId];
// Siring is okay if they have same owner, or if the matron's owner was given
// permission to breed with this sire.
return (matronOwner == sireOwner || sireAllowedToAddress[_sireId] == matronOwner);
}
/// @dev Set the cooldownEndTime for the given Kitty, based on its current cooldownIndex.
/// Also increments the cooldownIndex (unless it has hit the cap).
/// @param _kitten A reference to the Kitty in storage which needs its timer started.
function _triggerCooldown(Kitty storage _kitten) internal {
// Compute an estimation of the cooldown time in blocks (based on current cooldownIndex).
_kitten.cooldownEndBlock = uint64((cooldowns[_kitten.cooldownIndex]/secondsPerBlock) + block.number);
// Increment the breeding count, clamping it at 13, which is the length of the
// cooldowns array. We could check the array size dynamically, but hard-coding
// this as a constant saves gas. Yay, Solidity!
if (_kitten.cooldownIndex < 13) {
_kitten.cooldownIndex += 1;
}
}
/// @notice Grants approval to another user to sire with one of your Kitties.
/// @param _addr The address that will be able to sire with your Kitty. Set to
/// address(0) to clear all siring approvals for this Kitty.
/// @param _sireId A Kitty that you own that _addr will now be able to sire with.
function approveSiring(address _addr, uint256 _sireId)
external
whenNotPaused
{
require(_owns(msg.sender, _sireId));
sireAllowedToAddress[_sireId] = _addr;
}
/// @dev Updates the minimum payment required for calling giveBirthAuto(). Can only
/// be called by the COO address. (This fee is used to offset the gas cost incurred
/// by the autobirth daemon).
function setAutoBirthFee(uint256 val) external onlyCOO {
autoBirthFee = val;
}
/// @dev Checks to see if a given Kitty is pregnant and (if so) if the gestation
/// period has passed.
function _isReadyToGiveBirth(Kitty _matron) private view returns (bool) {
return (_matron.siringWithId != 0) && (_matron.cooldownEndBlock <= uint64(block.number));
}
/// @notice Checks that a given kitten is able to breed (i.e. it is not pregnant or
/// in the middle of a siring cooldown).
/// @param _kittyId reference the id of the kitten, any user can inquire about it
function isReadyToBreed(uint256 _kittyId)
public
view
returns (bool)
{
require(_kittyId > 0);
Kitty storage kit = kitties[_kittyId];
return _isReadyToBreed(kit);
}
/// @dev Checks whether a kitty is currently pregnant.
/// @param _kittyId reference the id of the kitten, any user can inquire about it
function isPregnant(uint256 _kittyId)
public
view
returns (bool)
{
require(_kittyId > 0);
// A kitty is pregnant if and only if this field is set
return kitties[_kittyId].siringWithId != 0;
}
/// @dev Internal check to see if a given sire and matron are a valid mating pair. DOES NOT
/// check ownership permissions (that is up to the caller).
/// @param _matron A reference to the Kitty struct of the potential matron.
/// @param _matronId The matron's ID.
/// @param _sire A reference to the Kitty struct of the potential sire.
/// @param _sireId The sire's ID
function _isValidMatingPair(
Kitty storage _matron,
uint256 _matronId,
Kitty storage _sire,
uint256 _sireId
)
private
view
returns(bool)
{
// A Kitty can't breed with itself!
if (_matronId == _sireId) {
return false;
}
// Kitties can't breed with their parents.
if (_matron.matronId == _sireId || _matron.sireId == _sireId) {
return false;
}
if (_sire.matronId == _matronId || _sire.sireId == _matronId) {
return false;
}
// We can short circuit the sibling check (below) if either cat is
// gen zero (has a matron ID of zero).
if (_sire.matronId == 0 || _matron.matronId == 0) {
return true;
}
// Kitties can't breed with full or half siblings.
if (_sire.matronId == _matron.matronId || _sire.matronId == _matron.sireId) {
return false;
}
if (_sire.sireId == _matron.matronId || _sire.sireId == _matron.sireId) {
return false;
}
// Everything seems cool! Let's get DTF.
return true;
}
/// @dev Internal check to see if a given sire and matron are a valid mating pair for
/// breeding via auction (i.e. skips ownership and siring approval checks).
function _canBreedWithViaAuction(uint256 _matronId, uint256 _sireId)
internal
view
returns (bool)
{
Kitty storage matron = kitties[_matronId];
Kitty storage sire = kitties[_sireId];
return _isValidMatingPair(matron, _matronId, sire, _sireId);
}
/// @notice Checks to see if two cats can breed together, including checks for
/// ownership and siring approvals. Does NOT check that both cats are ready for
/// breeding (i.e. breedWith could still fail until the cooldowns are finished).
/// TODO: Shouldn't this check pregnancy and cooldowns?!?
/// @param _matronId The ID of the proposed matron.
/// @param _sireId The ID of the proposed sire.
function canBreedWith(uint256 _matronId, uint256 _sireId)
external
view
returns(bool)
{
require(_matronId > 0);
require(_sireId > 0);
Kitty storage matron = kitties[_matronId];
Kitty storage sire = kitties[_sireId];
return _isValidMatingPair(matron, _matronId, sire, _sireId) &&
_isSiringPermitted(_sireId, _matronId);
}
/// @dev Internal utility function to initiate breeding, assumes that all breeding
/// requirements have been checked.
function _breedWith(uint256 _matronId, uint256 _sireId) internal {
// Grab a reference to the Kitties from storage.
Kitty storage sire = kitties[_sireId];
Kitty storage matron = kitties[_matronId];
// Mark the matron as pregnant, keeping track of who the sire is.
matron.siringWithId = uint32(_sireId);
// Trigger the cooldown for both parents.
_triggerCooldown(sire);
_triggerCooldown(matron);
// Clear siring permission for both parents. This may not be strictly necessary
// but it's likely to avoid confusion!
delete sireAllowedToAddress[_matronId];
delete sireAllowedToAddress[_sireId];
// Every time a kitty gets pregnant, counter is incremented.
pregnantKitties++;
// Emit the pregnancy event.
Pregnant(kittyIndexToOwner[_matronId], _matronId, _sireId, matron.cooldownEndBlock);
}
/// @notice Breed a Kitty you own (as matron) with a sire that you own, or for which you
/// have previously been given Siring approval. Will either make your cat pregnant, or will
/// fail entirely. Requires a pre-payment of the fee given out to the first caller of giveBirth()
/// @param _matronId The ID of the Kitty acting as matron (will end up pregnant if successful)
/// @param _sireId The ID of the Kitty acting as sire (will begin its siring cooldown if successful)
function breedWithAuto(uint256 _matronId, uint256 _sireId)
external
payable
whenNotPaused
{
// Checks for payment.
require(msg.value >= autoBirthFee);
// Caller must own the matron.
require(_owns(msg.sender, _matronId));
// Neither sire nor matron are allowed to be on auction during a normal
// breeding operation, but we don't need to check that explicitly.
// For matron: The caller of this function can't be the owner of the matron
// because the owner of a Kitty on auction is the auction house, and the
// auction house will never call breedWith().
// For sire: Similarly, a sire on auction will be owned by the auction house
// and the act of transferring ownership will have cleared any oustanding
// siring approval.
// Thus we don't need to spend gas explicitly checking to see if either cat
// is on auction.
// Check that matron and sire are both owned by caller, or that the sire
// has given siring permission to caller (i.e. matron's owner).
// Will fail for _sireId = 0
require(_isSiringPermitted(_sireId, _matronId));
// Grab a reference to the potential matron
Kitty storage matron = kitties[_matronId];
// Make sure matron isn't pregnant, or in the middle of a siring cooldown
require(_isReadyToBreed(matron));
// Grab a reference to the potential sire
Kitty storage sire = kitties[_sireId];
// Make sure sire isn't pregnant, or in the middle of a siring cooldown
require(_isReadyToBreed(sire));