bip322-js
Version:
A Javascript library that provides utility functions related to the BIP-322 signature scheme
42 lines • 1.99 kB
JavaScript
;
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
// Import dependency
const VarInt_1 = __importDefault(require("./VarInt"));
const BufferUtil_1 = __importDefault(require("./BufferUtil"));
/**
* Class that implement variable length string (VarStr) in Javascript.
* Reference: https://en.bitcoin.it/wiki/Protocol_documentation#Variable_length_string
*/
class VarStr {
/**
* Encode a string buffer as a variable length string.
* Reference: https://github.com/buidl-bitcoin/buidl-python/blob/d79e9808e8ca60975d315be41293cb40d968626d/buidl/helper.py#L203
* @param s String buffer to be encoded
* @returns Encoded varstr
*/
static encode(s) {
// Encode the length of the string using encodeVarInt
const lengthBuffer = VarInt_1.default.encode(s.length);
// Concat the actual string right after the length of the string
return Buffer.concat([lengthBuffer, s]);
}
/**
* Decode a variable length string from a Buffer into a string buffer.
* Reference: https://github.com/buidl-bitcoin/buidl-python/blob/d79e9808e8ca60975d315be41293cb40d968626d/buidl/helper.py#L194
* @param v Varstr to be decoded
* @returns Decoded string buffer
*/
static decode(v) {
// Find the length of the string by using read_varint on the string
const length = VarInt_1.default.decode(v);
// Get the length of the VarInt used to represent the length of the string
const lengthByteLength = VarInt_1.default.encode(length).byteLength;
// Return from lengthByteLength to (length + lengthByteLength) in the buffer which contain the actual string
return BufferUtil_1.default.ensureBuffer(v.subarray(lengthByteLength, length + lengthByteLength));
}
}
exports.default = VarStr;
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