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
|
import { AssetData, AssetProxyId, ERC20AssetData, ERC721AssetData } from '@0x/types';
import { BigNumber } from '@0x/utils';
import ethAbi = require('ethereumjs-abi');
import ethUtil = require('ethereumjs-util');
import { constants } from './constants';
export const assetDataUtils = {
/**
* Encodes an ERC20 token address into a hex encoded assetData string, usable in the makerAssetData or
* takerAssetData fields in a 0x order.
* @param tokenAddress The ERC20 token address to encode
* @return The hex encoded assetData string
*/
encodeERC20AssetData(tokenAddress: string): string {
return ethUtil.bufferToHex(ethAbi.simpleEncode('ERC20Token(address)', tokenAddress));
},
/**
* Decodes an ERC20 assetData hex string into it's corresponding ERC20 tokenAddress & assetProxyId
* @param assetData Hex encoded assetData string to decode
* @return An object containing the decoded tokenAddress & assetProxyId
*/
decodeERC20AssetData(assetData: string): ERC20AssetData {
const data = ethUtil.toBuffer(assetData);
if (data.byteLength < constants.ERC20_ASSET_DATA_BYTE_LENGTH) {
throw new Error(
`Could not decode ERC20 Proxy Data. Expected length of encoded data to be at least ${
constants.ERC20_ASSET_DATA_BYTE_LENGTH
}. Got ${data.byteLength}`,
);
}
const assetProxyId = ethUtil.bufferToHex(data.slice(0, constants.SELECTOR_LENGTH));
if (assetProxyId !== AssetProxyId.ERC20) {
throw new Error(
`Could not decode ERC20 Proxy Data. Expected Asset Proxy Id to be ERC20 (${
AssetProxyId.ERC20
}), but got ${assetProxyId}`,
);
}
const [tokenAddress] = ethAbi.rawDecode(['address'], data.slice(constants.SELECTOR_LENGTH));
return {
assetProxyId,
tokenAddress: ethUtil.addHexPrefix(tokenAddress),
};
},
/**
* Encodes an ERC721 token address into a hex encoded assetData string, usable in the makerAssetData or
* takerAssetData fields in a 0x order.
* @param tokenAddress The ERC721 token address to encode
* @param tokenId The ERC721 tokenId to encode
* @return The hex encoded assetData string
*/
encodeERC721AssetData(tokenAddress: string, tokenId: BigNumber): string {
// TODO: Pass `tokendId` as a BigNumber.
return ethUtil.bufferToHex(
ethAbi.simpleEncode(
'ERC721Token(address,uint256)',
tokenAddress,
`0x${tokenId.toString(constants.BASE_16)}`,
),
);
},
/**
* Decodes an ERC721 assetData hex string into it's corresponding ERC721 tokenAddress, tokenId & assetProxyId
* @param assetData Hex encoded assetData string to decode
* @return An object containing the decoded tokenAddress, tokenId & assetProxyId
*/
decodeERC721AssetData(assetData: string): ERC721AssetData {
const data = ethUtil.toBuffer(assetData);
if (data.byteLength < constants.ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH) {
throw new Error(
`Could not decode ERC721 Asset Data. Expected length of encoded data to be at least ${
constants.ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH
}. Got ${data.byteLength}`,
);
}
const assetProxyId = ethUtil.bufferToHex(data.slice(0, constants.SELECTOR_LENGTH));
if (assetProxyId !== AssetProxyId.ERC721) {
throw new Error(
`Could not decode ERC721 Asset Data. Expected Asset Proxy Id to be ERC721 (${
AssetProxyId.ERC721
}), but got ${assetProxyId}`,
);
}
const [tokenAddress, tokenId] = ethAbi.rawDecode(['address', 'uint256'], data.slice(constants.SELECTOR_LENGTH));
return {
assetProxyId,
tokenAddress: ethUtil.addHexPrefix(tokenAddress),
tokenId: new BigNumber(tokenId.toString()),
};
},
/**
* Decode and return the assetProxyId from the assetData
* @param assetData Hex encoded assetData string to decode
* @return The assetProxyId
*/
decodeAssetProxyId(assetData: string): AssetProxyId {
const encodedAssetData = ethUtil.toBuffer(assetData);
if (encodedAssetData.byteLength < constants.SELECTOR_LENGTH) {
throw new Error(
`Could not decode assetData. Expected length of encoded data to be at least 4. Got ${
encodedAssetData.byteLength
}`,
);
}
const encodedAssetProxyId = encodedAssetData.slice(0, constants.SELECTOR_LENGTH);
const assetProxyId = decodeAssetProxyId(encodedAssetProxyId);
return assetProxyId;
},
/**
* Decode any assetData into it's corresponding assetData object
* @param assetData Hex encoded assetData string to decode
* @return Either a ERC20 or ERC721 assetData object
*/
decodeAssetDataOrThrow(assetData: string): AssetData {
const assetProxyId = assetDataUtils.decodeAssetProxyId(assetData);
switch (assetProxyId) {
case AssetProxyId.ERC20:
const erc20AssetData = assetDataUtils.decodeERC20AssetData(assetData);
return erc20AssetData;
case AssetProxyId.ERC721:
const erc721AssetData = assetDataUtils.decodeERC721AssetData(assetData);
return erc721AssetData;
default:
throw new Error(`Unrecognized asset proxy id: ${assetProxyId}`);
}
},
};
function decodeAssetProxyId(encodedAssetProxyId: Buffer): AssetProxyId {
const hexString = ethUtil.bufferToHex(encodedAssetProxyId);
if (hexString === AssetProxyId.ERC20) {
return AssetProxyId.ERC20;
}
if (hexString === AssetProxyId.ERC721) {
return AssetProxyId.ERC721;
}
throw new Error(`Invalid ProxyId: ${hexString}`);
}
|
