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
|
import {
Artifact,
BlockParamLiteral,
ContractAbi,
FilterObject,
LogEntry,
LogWithDecodedArgs,
RawLog,
} from '@0xproject/types';
import { AbiDecoder, intervalUtils } from '@0xproject/utils';
import { Web3Wrapper } from '@0xproject/web3-wrapper';
import { Block, BlockAndLogStreamer } from 'ethereumjs-blockstream';
import * as _ from 'lodash';
import {
BlockRange,
ContractEventArgs,
ContractEvents,
ContractWrappersError,
EventCallback,
IndexedFilterValues,
InternalContractWrappersError,
} from '../types';
import { constants } from '../utils/constants';
import { filterUtils } from '../utils/filter_utils';
const CONTRACT_NAME_TO_NOT_FOUND_ERROR: {
[contractName: string]: ContractWrappersError;
} = {
ZRX: ContractWrappersError.ZRXContractDoesNotExist,
EtherToken: ContractWrappersError.EtherTokenContractDoesNotExist,
Token: ContractWrappersError.TokenContractDoesNotExist,
TokenRegistry: ContractWrappersError.TokenRegistryContractDoesNotExist,
TokenTransferProxy: ContractWrappersError.TokenTransferProxyContractDoesNotExist,
Exchange: ContractWrappersError.ExchangeContractDoesNotExist,
};
export class ContractWrapper {
protected _web3Wrapper: Web3Wrapper;
protected _networkId: number;
private _blockAndLogStreamerIfExists?: BlockAndLogStreamer;
private _blockAndLogStreamIntervalIfExists?: NodeJS.Timer;
private _filters: { [filterToken: string]: FilterObject };
private _filterCallbacks: {
[filterToken: string]: EventCallback<ContractEventArgs>;
};
private _onLogAddedSubscriptionToken: string | undefined;
private _onLogRemovedSubscriptionToken: string | undefined;
constructor(web3Wrapper: Web3Wrapper, networkId: number) {
this._web3Wrapper = web3Wrapper;
this._networkId = networkId;
this._filters = {};
this._filterCallbacks = {};
this._blockAndLogStreamerIfExists = undefined;
this._onLogAddedSubscriptionToken = undefined;
this._onLogRemovedSubscriptionToken = undefined;
}
protected _unsubscribeAll(): void {
const filterTokens = _.keys(this._filterCallbacks);
_.each(filterTokens, filterToken => {
this._unsubscribe(filterToken);
});
}
protected _unsubscribe(filterToken: string, err?: Error): void {
if (_.isUndefined(this._filters[filterToken])) {
throw new Error(ContractWrappersError.SubscriptionNotFound);
}
if (!_.isUndefined(err)) {
const callback = this._filterCallbacks[filterToken];
callback(err, undefined);
}
delete this._filters[filterToken];
delete this._filterCallbacks[filterToken];
if (_.isEmpty(this._filters)) {
this._stopBlockAndLogStream();
}
}
protected _subscribe<ArgsType extends ContractEventArgs>(
address: string,
eventName: ContractEvents,
indexFilterValues: IndexedFilterValues,
abi: ContractAbi,
callback: EventCallback<ArgsType>,
): string {
const filter = filterUtils.getFilter(address, eventName, indexFilterValues, abi);
if (_.isUndefined(this._blockAndLogStreamerIfExists)) {
this._startBlockAndLogStream();
}
const filterToken = filterUtils.generateUUID();
this._filters[filterToken] = filter;
this._filterCallbacks[filterToken] = callback as EventCallback<ContractEventArgs>;
return filterToken;
}
protected async _getLogsAsync<ArgsType extends ContractEventArgs>(
address: string,
eventName: ContractEvents,
blockRange: BlockRange,
indexFilterValues: IndexedFilterValues,
abi: ContractAbi,
): Promise<Array<LogWithDecodedArgs<ArgsType>>> {
const filter = filterUtils.getFilter(address, eventName, indexFilterValues, abi, blockRange);
const logs = await this._web3Wrapper.getLogsAsync(filter);
const logsWithDecodedArguments = _.map(logs, this._tryToDecodeLogOrNoop.bind(this));
return logsWithDecodedArguments;
}
protected _tryToDecodeLogOrNoop<ArgsType extends ContractEventArgs>(
log: LogEntry,
): LogWithDecodedArgs<ArgsType> | RawLog {
if (_.isUndefined(this._web3Wrapper.abiDecoder)) {
throw new Error(InternalContractWrappersError.NoAbiDecoder);
}
const logWithDecodedArgs = this._web3Wrapper.abiDecoder.tryToDecodeLogOrNoop(log);
return logWithDecodedArgs;
}
protected async _getContractAbiAndAddressFromArtifactsAsync(
artifact: Artifact,
addressIfExists?: string,
): Promise<[ContractAbi, string]> {
let contractAddress: string;
if (_.isUndefined(addressIfExists)) {
if (_.isUndefined(artifact.networks[this._networkId])) {
throw new Error(ContractWrappersError.ContractNotDeployedOnNetwork);
}
contractAddress = artifact.networks[this._networkId].address.toLowerCase();
} else {
contractAddress = addressIfExists;
}
const doesContractExist = await this._web3Wrapper.doesContractExistAtAddressAsync(contractAddress);
if (!doesContractExist) {
throw new Error(CONTRACT_NAME_TO_NOT_FOUND_ERROR[artifact.contract_name]);
}
const abiAndAddress: [ContractAbi, string] = [artifact.abi, contractAddress];
return abiAndAddress;
}
protected _getContractAddress(artifact: Artifact, addressIfExists?: string): string {
if (_.isUndefined(addressIfExists)) {
const contractAddress = artifact.networks[this._networkId].address;
if (_.isUndefined(contractAddress)) {
throw new Error(ContractWrappersError.ExchangeContractDoesNotExist);
}
return contractAddress;
} else {
return addressIfExists;
}
}
private _onLogStateChanged<ArgsType extends ContractEventArgs>(isRemoved: boolean, log: LogEntry): void {
_.forEach(this._filters, (filter: FilterObject, filterToken: string) => {
if (filterUtils.matchesFilter(log, filter)) {
const decodedLog = this._tryToDecodeLogOrNoop(log) as LogWithDecodedArgs<ArgsType>;
const logEvent = {
log: decodedLog,
isRemoved,
};
this._filterCallbacks[filterToken](null, logEvent);
}
});
}
private _startBlockAndLogStream(): void {
if (!_.isUndefined(this._blockAndLogStreamerIfExists)) {
throw new Error(ContractWrappersError.SubscriptionAlreadyPresent);
}
this._blockAndLogStreamerIfExists = new BlockAndLogStreamer(
this._web3Wrapper.getBlockAsync.bind(this._web3Wrapper),
this._web3Wrapper.getLogsAsync.bind(this._web3Wrapper),
);
const catchAllLogFilter = {};
this._blockAndLogStreamerIfExists.addLogFilter(catchAllLogFilter);
this._blockAndLogStreamIntervalIfExists = intervalUtils.setAsyncExcludingInterval(
this._reconcileBlockAsync.bind(this),
constants.DEFAULT_BLOCK_POLLING_INTERVAL,
this._onReconcileBlockError.bind(this),
);
let isRemoved = false;
this._onLogAddedSubscriptionToken = this._blockAndLogStreamerIfExists.subscribeToOnLogAdded(
this._onLogStateChanged.bind(this, isRemoved),
);
isRemoved = true;
this._onLogRemovedSubscriptionToken = this._blockAndLogStreamerIfExists.subscribeToOnLogRemoved(
this._onLogStateChanged.bind(this, isRemoved),
);
}
private _onReconcileBlockError(err: Error): void {
const filterTokens = _.keys(this._filterCallbacks);
_.each(filterTokens, filterToken => {
this._unsubscribe(filterToken, err);
});
}
private _setNetworkId(networkId: number): void {
this._networkId = networkId;
}
private _stopBlockAndLogStream(): void {
if (_.isUndefined(this._blockAndLogStreamerIfExists)) {
throw new Error(ContractWrappersError.SubscriptionNotFound);
}
this._blockAndLogStreamerIfExists.unsubscribeFromOnLogAdded(this._onLogAddedSubscriptionToken as string);
this._blockAndLogStreamerIfExists.unsubscribeFromOnLogRemoved(this._onLogRemovedSubscriptionToken as string);
intervalUtils.clearAsyncExcludingInterval(this._blockAndLogStreamIntervalIfExists as NodeJS.Timer);
delete this._blockAndLogStreamerIfExists;
}
private async _reconcileBlockAsync(): Promise<void> {
const latestBlock = await this._web3Wrapper.getBlockAsync(BlockParamLiteral.Latest);
// We need to coerce to Block type cause Web3.Block includes types for mempool blocks
if (!_.isUndefined(this._blockAndLogStreamerIfExists)) {
// If we clear the interval while fetching the block - this._blockAndLogStreamer will be undefined
await this._blockAndLogStreamerIfExists.reconcileNewBlock((latestBlock as any) as Block);
}
}
}
|
