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Decoder works for uints with width less than 256

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This commit is contained in:
Greg Hysen
2018-11-12 17:28:46 -08:00
parent c5d252ba4a
commit 2a6b358717
1 changed files with 12 additions and 12 deletions
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24
packages/order-utils/test/abi/evm_data_types.ts
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@@ -146,34 +146,34 @@ abstract class Number extends PayloadDataType {
}
public decodeValue(calldata: RawCalldata): BigNumber {
const decodedValueBuf = calldata.popWord();
const decodedValueHex = ethUtil.bufferToHex(decodedValueBuf);
let decodedValue = new BigNumber(decodedValueHex, 16);
const paddedValueBuf = calldata.popWord();
const paddedValueHex = ethUtil.bufferToHex(paddedValueBuf);
let value = new BigNumber(paddedValueHex, 16);
if (this instanceof Int) {
// Check if we're negative
const binBase = 2;
const decodedValueBin = decodedValue.toString(binBase);
if (decodedValueBin[0] === '1') {
const paddedValueBin = value.toString(binBase);
const valueBin = paddedValueBin.slice(paddedValueBin.length - this.width);
if (valueBin[0].startsWith('1')) {
// Negative
// Step 1/3: Invert binary value
const bitsInEvmWord = 256;
let invertedValueBin = '1'.repeat(bitsInEvmWord - decodedValueBin.length);
_.each(decodedValueBin, (bit: string) => {
let invertedValueBin = '';
_.each(valueBin, (bit: string) => {
invertedValueBin += bit === '1' ? '0' : '1';
});
const invertedValue = new BigNumber(invertedValueBin, binBase);
// Step 2/3: Add 1 to inverted value
// The result is the two's-complement represent of the input value.
const positiveDecodedValue = invertedValue.plus(binBase);
const positiveValue = invertedValue.plus(1);
// Step 3/3: Invert positive value
const negativeDecodedValue = positiveDecodedValue.times(-1);
decodedValue = negativeDecodedValue;
const negativeValue = positiveValue.times(-1);
value = negativeValue;
}
}
return decodedValue;
return value;
}
public abstract getMaxValue(): BigNumber;