ripple-binary-codec
Version:
XRP Ledger binary codec
137 lines • 4.78 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.compare = exports.equal = exports.readUInt32BE = exports.readUInt16BE = exports.writeUInt32BE = exports.writeUInt16BE = exports.writeUInt8 = void 0;
/**
* Writes value to array at the specified offset. The value must be a valid unsigned 8-bit integer.
* @param array Uint8Array to be written to
* @param value Number to be written to array.
* @param offset plus the number of bytes written.
*/
function writeUInt8(array, value, offset) {
value = Number(value);
array[offset] = value;
}
exports.writeUInt8 = writeUInt8;
/**
* Writes value to array at the specified offset as big-endian. The value must be a valid unsigned 16-bit integer.
* @param array Uint8Array to be written to
* @param value Number to be written to array.
* @param offset plus the number of bytes written.
*/
function writeUInt16BE(array, value, offset) {
value = Number(value);
array[offset] = value >>> 8;
array[offset + 1] = value;
}
exports.writeUInt16BE = writeUInt16BE;
/**
* Writes value to array at the specified offset as big-endian. The value must be a valid unsigned 32-bit integer.
* @param array Uint8Array to be written to
* @param value Number to be written to array.
* @param offset plus the number of bytes written.
*/
function writeUInt32BE(array, value, offset) {
array[offset] = (value >>> 24) & 0xff;
array[offset + 1] = (value >>> 16) & 0xff;
array[offset + 2] = (value >>> 8) & 0xff;
array[offset + 3] = value & 0xff;
}
exports.writeUInt32BE = writeUInt32BE;
/**
* Reads an unsigned, big-endian 16-bit integer from the array at the specified offset.
* @param array Uint8Array to read
* @param offset Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 2
*/
function readUInt16BE(array, offset) {
return new DataView(array.buffer).getUint16(offset, false).toString(10);
}
exports.readUInt16BE = readUInt16BE;
/**
* Reads an unsigned, big-endian 16-bit integer from the array at the specified offset.
* @param array Uint8Array to read
* @param offset Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 4
*/
function readUInt32BE(array, offset) {
return new DataView(array.buffer).getUint32(offset, false).toString(10);
}
exports.readUInt32BE = readUInt32BE;
/**
* Compares two Uint8Array or ArrayBuffers
* @param a first array to compare
* @param b second array to compare
*/
function equal(a, b) {
const aUInt = a instanceof ArrayBuffer ? new Uint8Array(a, 0) : a;
const bUInt = b instanceof ArrayBuffer ? new Uint8Array(b, 0) : b;
if (aUInt.byteLength != bUInt.byteLength)
return false;
if (aligned32(aUInt) && aligned32(bUInt))
return compare32(aUInt, bUInt) === 0;
if (aligned16(aUInt) && aligned16(bUInt))
return compare16(aUInt, bUInt) === 0;
return compare8(aUInt, bUInt) === 0;
}
exports.equal = equal;
/**
* Compares two 8 bit aligned arrays
* @param a first array to compare
* @param b second array to compare
*/
function compare8(a, b) {
const ua = new Uint8Array(a.buffer, a.byteOffset, a.byteLength);
const ub = new Uint8Array(b.buffer, b.byteOffset, b.byteLength);
return compare(ua, ub);
}
/**
* Compares two 16 bit aligned arrays
* @param a first array to compare
* @param b second array to compare
*/
function compare16(a, b) {
const ua = new Uint16Array(a.buffer, a.byteOffset, a.byteLength / 2);
const ub = new Uint16Array(b.buffer, b.byteOffset, b.byteLength / 2);
return compare(ua, ub);
}
/**
* Compares two 32 bit aligned arrays
* @param a first array to compare
* @param b second array to compare
*/
function compare32(a, b) {
const ua = new Uint32Array(a.buffer, a.byteOffset, a.byteLength / 4);
const ub = new Uint32Array(b.buffer, b.byteOffset, b.byteLength / 4);
return compare(ua, ub);
}
/**
* Compare two TypedArrays
* @param a first array to compare
* @param b second array to compare
*/
function compare(a, b) {
if (a.byteLength !== b.byteLength) {
throw new Error('Cannot compare arrays of different length');
}
for (let i = 0; i < a.length - 1; i += 1) {
if (a[i] > b[i])
return 1;
if (a[i] < b[i])
return -1;
}
return 0;
}
exports.compare = compare;
/**
* Determine if TypedArray is 16 bit aligned
* @param array The array to check
*/
function aligned16(array) {
return array.byteOffset % 2 === 0 && array.byteLength % 2 === 0;
}
/**
* Determine if TypedArray is 32 bit aligned
* @param array The array to check
*/
function aligned32(array) {
return array.byteOffset % 4 === 0 && array.byteLength % 4 === 0;
}
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