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Diffstat (limited to 'packages/order-utils/src/asset_data_utils.ts')
| -rw-r--r-- | packages/order-utils/src/asset_data_utils.ts | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/packages/order-utils/src/asset_data_utils.ts b/packages/order-utils/src/asset_data_utils.ts new file mode 100644 index 000000000..a9601e9ea --- /dev/null +++ b/packages/order-utils/src/asset_data_utils.ts @@ -0,0 +1,144 @@ +import { AssetProxyId, ERC20AssetData, ERC721AssetData } from '@0xproject/types'; +import { BigNumber } from '@0xproject/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 ${assetProxyId}`, + ); + } + const [tokenAddress] = ethAbi.rawDecode(['address'], data.slice(constants.SELECTOR_LENGTH)); + return { + assetProxyId, + tokenAddress: ethUtil.addHexPrefix(tokenAddress), + }; + }, + /** + * Encodes an ERC721 token address into a hex encoded assetData string, usable in the makerAssetData or + * takerAssetData fields in a 0x order. + * @param tokenAddress The ERC721 token address to encode + * @param tokenId The ERC721 tokenId to encode + * @return The hex encoded assetData string + */ + encodeERC721AssetData(tokenAddress: string, tokenId: BigNumber, receiverData?: string): string { + // TODO: Pass `tokendId` as a BigNumber. + return ethUtil.bufferToHex( + ethAbi.simpleEncode( + 'ERC721Token(address,uint256,bytes)', + tokenAddress, + `0x${tokenId.toString(constants.BASE_16)}`, + ethUtil.toBuffer(receiverData || '0x'), + ), + ); + }, + /** + * 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, receiverData] = ethAbi.rawDecode( + ['address', 'uint256', 'bytes'], + data.slice(constants.SELECTOR_LENGTH), + ); + return { + assetProxyId, + tokenAddress: ethUtil.addHexPrefix(tokenAddress), + tokenId: new BigNumber(tokenId.toString()), + receiverData: ethUtil.bufferToHex(receiverData), + }; + }, + /** + * 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): ERC20AssetData | ERC721AssetData { + 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}`); +} |