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- //See: https://github.com/ethereum/wiki/wiki/RLP
- import { hexlify } from "./data.js";
- import { assert, assertArgument } from "./errors.js";
- import { getBytes } from "./data.js";
- function hexlifyByte(value) {
- let result = value.toString(16);
- while (result.length < 2) {
- result = "0" + result;
- }
- return "0x" + result;
- }
- function unarrayifyInteger(data, offset, length) {
- let result = 0;
- for (let i = 0; i < length; i++) {
- result = (result * 256) + data[offset + i];
- }
- return result;
- }
- function _decodeChildren(data, offset, childOffset, length) {
- const result = [];
- while (childOffset < offset + 1 + length) {
- const decoded = _decode(data, childOffset);
- result.push(decoded.result);
- childOffset += decoded.consumed;
- assert(childOffset <= offset + 1 + length, "child data too short", "BUFFER_OVERRUN", {
- buffer: data, length, offset
- });
- }
- return { consumed: (1 + length), result: result };
- }
- // returns { consumed: number, result: Object }
- function _decode(data, offset) {
- assert(data.length !== 0, "data too short", "BUFFER_OVERRUN", {
- buffer: data, length: 0, offset: 1
- });
- const checkOffset = (offset) => {
- assert(offset <= data.length, "data short segment too short", "BUFFER_OVERRUN", {
- buffer: data, length: data.length, offset
- });
- };
- // Array with extra length prefix
- if (data[offset] >= 0xf8) {
- const lengthLength = data[offset] - 0xf7;
- checkOffset(offset + 1 + lengthLength);
- const length = unarrayifyInteger(data, offset + 1, lengthLength);
- checkOffset(offset + 1 + lengthLength + length);
- return _decodeChildren(data, offset, offset + 1 + lengthLength, lengthLength + length);
- }
- else if (data[offset] >= 0xc0) {
- const length = data[offset] - 0xc0;
- checkOffset(offset + 1 + length);
- return _decodeChildren(data, offset, offset + 1, length);
- }
- else if (data[offset] >= 0xb8) {
- const lengthLength = data[offset] - 0xb7;
- checkOffset(offset + 1 + lengthLength);
- const length = unarrayifyInteger(data, offset + 1, lengthLength);
- checkOffset(offset + 1 + lengthLength + length);
- const result = hexlify(data.slice(offset + 1 + lengthLength, offset + 1 + lengthLength + length));
- return { consumed: (1 + lengthLength + length), result: result };
- }
- else if (data[offset] >= 0x80) {
- const length = data[offset] - 0x80;
- checkOffset(offset + 1 + length);
- const result = hexlify(data.slice(offset + 1, offset + 1 + length));
- return { consumed: (1 + length), result: result };
- }
- return { consumed: 1, result: hexlifyByte(data[offset]) };
- }
- /**
- * Decodes %%data%% into the structured data it represents.
- */
- export function decodeRlp(_data) {
- const data = getBytes(_data, "data");
- const decoded = _decode(data, 0);
- assertArgument(decoded.consumed === data.length, "unexpected junk after rlp payload", "data", _data);
- return decoded.result;
- }
- //# sourceMappingURL=rlp-decode.js.map
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