122 lines
3.6 KiB
JavaScript
122 lines
3.6 KiB
JavaScript
import { hexlify, isBytesLike } from "./data.js";
|
|
import { logger } from "./logger.js";
|
|
const BN_0 = BigInt(0);
|
|
const BN_1 = BigInt(1);
|
|
/**
|
|
* Convert %%value%% from a twos-compliment value of %%width%% bits.
|
|
*/
|
|
export function fromTwos(_value, _width) {
|
|
const value = logger.getBigInt(_value, "value");
|
|
const width = BigInt(logger.getNumber(_width, "width"));
|
|
// Top bit set; treat as a negative value
|
|
if (value >> (width - BN_1)) {
|
|
const mask = (BN_1 << width) - BN_1;
|
|
return -(((~value) & mask) + BN_1);
|
|
}
|
|
return value;
|
|
}
|
|
/**
|
|
* Convert %%value%% to a twos-compliment value of %%width%% bits.
|
|
*/
|
|
export function toTwos(_value, _width) {
|
|
const value = logger.getBigInt(_value, "value");
|
|
const width = BigInt(logger.getNumber(_width, "width"));
|
|
if (value < BN_0) {
|
|
const mask = (BN_1 << width) - BN_1;
|
|
return ((~(-value)) & mask) + BN_1;
|
|
}
|
|
return value;
|
|
}
|
|
/**
|
|
* Mask %%value%% with a bitmask of %%bits%% ones.
|
|
*/
|
|
export function mask(_value, _bits) {
|
|
const value = logger.getBigInt(_value, "value");
|
|
const bits = BigInt(logger.getNumber(_bits, "bits"));
|
|
return value & ((BN_1 << bits) - BN_1);
|
|
}
|
|
/*
|
|
* Converts %%value%% to a BigInt. If %%value%% is a Uint8Array, it
|
|
* is treated as Big Endian data.
|
|
*/
|
|
const Nibbles = "0123456789abcdef";
|
|
export function toBigInt(value) {
|
|
if (value instanceof Uint8Array) {
|
|
let result = "0x0";
|
|
for (const v of value) {
|
|
result += Nibbles[v >> 4];
|
|
result += Nibbles[v & 0x0f];
|
|
}
|
|
return BigInt(result);
|
|
}
|
|
return logger.getBigInt(value);
|
|
}
|
|
/*
|
|
* Converts %%value%% to a number. If %%value%% is a Uint8Array, it
|
|
* is treated as Big Endian data. Throws if the value is not safe.
|
|
*/
|
|
export function toNumber(value) {
|
|
return logger.getNumber(toBigInt(value));
|
|
}
|
|
/**
|
|
* Converts %%value%% to a Big Endian hexstring, optionally padded to
|
|
* %%width%% bytes.
|
|
*/
|
|
// Converts value to hex, optionally padding on the left to width bytes
|
|
export function toHex(_value, _width) {
|
|
const value = logger.getBigInt(_value, "value");
|
|
if (value < 0) {
|
|
throw new Error("cannot convert negative value to hex");
|
|
}
|
|
let result = value.toString(16);
|
|
if (_width == null) {
|
|
// Ensure the value is of even length
|
|
if (result.length % 2) {
|
|
result = "0" + result;
|
|
}
|
|
}
|
|
else {
|
|
const width = logger.getNumber(_width, "width");
|
|
if (width * 2 < result.length) {
|
|
throw new Error(`value ${value} exceeds width ${width}`);
|
|
}
|
|
// Pad the value to the required width
|
|
while (result.length < (width * 2)) {
|
|
result = "0" + result;
|
|
}
|
|
}
|
|
return "0x" + result;
|
|
}
|
|
/**
|
|
* Converts %%value%% to a Big Endian Uint8Array.
|
|
*/
|
|
export function toArray(_value) {
|
|
const value = logger.getBigInt(_value, "value");
|
|
if (value < 0) {
|
|
throw new Error("cannot convert negative value to hex");
|
|
}
|
|
if (value === BN_0) {
|
|
return new Uint8Array([]);
|
|
}
|
|
let hex = value.toString(16);
|
|
if (hex.length % 2) {
|
|
hex = "0" + hex;
|
|
}
|
|
const result = new Uint8Array(hex.length / 2);
|
|
for (let i = 0; i < result.length; i++) {
|
|
const offset = i * 2;
|
|
result[i] = parseInt(hex.substring(offset, offset + 2), 16);
|
|
}
|
|
return result;
|
|
}
|
|
export function toQuantity(value) {
|
|
let result = hexlify(isBytesLike(value) ? value : toArray(value)).substring(2);
|
|
while (result.substring(0, 1) === "0") {
|
|
result = result.substring(1);
|
|
}
|
|
if (result === "") {
|
|
result = "0";
|
|
}
|
|
return "0x" + result;
|
|
}
|
|
//# sourceMappingURL=maths.js.map
|