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/* tslint:disable prefer-function-over-method */
import { DataItem } from 'ethereum-types';
import * as ethUtil from 'ethereumjs-util';
import * as _ from 'lodash';
import { DataTypeFactory, PayloadDataType } from '../abstract_data_types';
import { RawCalldata } from '../calldata';
import * as Constants from '../constants';
export class DynamicBytes extends PayloadDataType {
private static readonly _SIZE_KNOWN_AT_COMPILE_TIME: boolean = false;
public static matchType(type: string): boolean {
return type === 'bytes';
}
public constructor(dataItem: DataItem, dataTypeFactory: DataTypeFactory) {
super(dataItem, dataTypeFactory, DynamicBytes._SIZE_KNOWN_AT_COMPILE_TIME);
if (!DynamicBytes.matchType(dataItem.type)) {
throw new Error(`Tried to instantiate DynamicBytes with bad input: ${dataItem}`);
}
}
public encodeValue(value: string | Buffer): Buffer {
if (typeof value === 'string' && !value.startsWith('0x')) {
throw new Error(`Tried to encode non-hex value. Value must inlcude '0x' prefix. Got '${value}'`);
}
const valueBuf = ethUtil.toBuffer(value);
if (value.length % 2 !== 0) {
throw new Error(`Tried to assign ${value}, which is contains a half-byte. Use full bytes only.`);
}
const wordsForValue = Math.ceil(valueBuf.byteLength / Constants.EVM_WORD_WIDTH_IN_BYTES);
const paddedDynamicBytesForValue = wordsForValue * Constants.EVM_WORD_WIDTH_IN_BYTES;
const paddedValueBuf = ethUtil.setLengthRight(valueBuf, paddedDynamicBytesForValue);
const paddedLengthBuf = ethUtil.setLengthLeft(
ethUtil.toBuffer(valueBuf.byteLength),
Constants.EVM_WORD_WIDTH_IN_BYTES,
);
const encodedValueBuf = Buffer.concat([paddedLengthBuf, paddedValueBuf]);
return encodedValueBuf;
}
public decodeValue(calldata: RawCalldata): string {
const lengthBuf = calldata.popWord();
const lengthHex = ethUtil.bufferToHex(lengthBuf);
const length = parseInt(lengthHex, Constants.HEX_BASE);
const wordsForValue = Math.ceil(length / Constants.EVM_WORD_WIDTH_IN_BYTES);
const paddedValueBuf = calldata.popWords(wordsForValue);
const valueBuf = paddedValueBuf.slice(0, length);
const decodedValue = ethUtil.bufferToHex(valueBuf);
return decodedValue;
}
public getSignature(): string {
return 'bytes';
}
}
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