ox
Version:
249 lines • 8.06 kB
JavaScript
import * as Bytes from './Bytes.js';
import * as Errors from './Errors.js';
import * as Hex from './Hex.js';
import * as Cursor from './internal/cursor.js';
/**
* Decodes a Recursive-Length Prefix (RLP) value into a {@link ox#Bytes.Bytes} value.
*
* @example
* ```ts twoslash
* import { Rlp } from 'ox'
* Rlp.toBytes('0x8b68656c6c6f20776f726c64')
* // Uint8Array([139, 104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100])
* ```
*
* @param value - The value to decode.
* @returns The decoded {@link ox#Bytes.Bytes} value.
*/
export function toBytes(value) {
return to(value, 'Bytes');
}
/**
* Decodes a Recursive-Length Prefix (RLP) value into a {@link ox#Hex.Hex} value.
*
* @example
* ```ts twoslash
* import { Rlp } from 'ox'
* Rlp.toHex('0x8b68656c6c6f20776f726c64')
* // 0x68656c6c6f20776f726c64
* ```
*
* @param value - The value to decode.
* @returns The decoded {@link ox#Hex.Hex} value.
*/
export function toHex(value) {
return to(value, 'Hex');
}
/////////////////////////////////////////////////////////////////////////////////
// Internal
/////////////////////////////////////////////////////////////////////////////////
/** @internal */
export function to(value, to) {
const to_ = to ?? (typeof value === 'string' ? 'Hex' : 'Bytes');
const bytes = (() => {
if (typeof value === 'string') {
if (value.length > 3 && value.length % 2 !== 0)
throw new Hex.InvalidLengthError(value);
return Bytes.fromHex(value);
}
return value;
})();
const cursor = Cursor.create(bytes, {
recursiveReadLimit: Number.POSITIVE_INFINITY,
});
const result = decodeRlpCursor(cursor, to_);
return result;
}
/** @internal */
/** @internal */
export function decodeRlpCursor(cursor, to = 'Hex') {
if (cursor.bytes.length === 0)
return (to === 'Hex' ? Hex.fromBytes(cursor.bytes) : cursor.bytes);
const prefix = cursor.readByte();
if (prefix < 0x80)
cursor.decrementPosition(1);
// bytes
if (prefix < 0xc0) {
const length = readLength(cursor, prefix, 0x80);
const bytes = cursor.readBytes(length);
return (to === 'Hex' ? Hex.fromBytes(bytes) : bytes);
}
// list
const length = readLength(cursor, prefix, 0xc0);
return readList(cursor, length, to);
}
/** @internal */
export function readLength(cursor, prefix, offset) {
if (offset === 0x80 && prefix < 0x80)
return 1;
if (prefix <= offset + 55)
return prefix - offset;
if (prefix === offset + 55 + 1)
return cursor.readUint8();
if (prefix === offset + 55 + 2)
return cursor.readUint16();
if (prefix === offset + 55 + 3)
return cursor.readUint24();
if (prefix === offset + 55 + 4)
return cursor.readUint32();
throw new Errors.BaseError('Invalid RLP prefix');
}
/** @internal */
export function readList(cursor, length, to) {
const position = cursor.position;
const value = [];
while (cursor.position - position < length)
value.push(decodeRlpCursor(cursor, to));
return value;
}
/**
* Encodes a {@link ox#Bytes.Bytes} or {@link ox#Hex.Hex} value into a Recursive-Length Prefix (RLP) value.
*
* @example
* ```ts twoslash
* import { Bytes, Rlp } from 'ox'
*
* Rlp.from('0x68656c6c6f20776f726c64', { as: 'Hex' })
* // @log: 0x8b68656c6c6f20776f726c64
*
* Rlp.from(Bytes.from([139, 104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100]), { as: 'Bytes' })
* // @log: Uint8Array([104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100])
* ```
*
* @param value - The {@link ox#Bytes.Bytes} or {@link ox#Hex.Hex} value to encode.
* @param options - Options.
* @returns The RLP value.
*/
export function from(value, options) {
const { as } = options;
const encodable = getEncodable(value);
const cursor = Cursor.create(new Uint8Array(encodable.length));
encodable.encode(cursor);
if (as === 'Hex')
return Hex.fromBytes(cursor.bytes);
return cursor.bytes;
}
/**
* Encodes a {@link ox#Bytes.Bytes} value into a Recursive-Length Prefix (RLP) value.
*
* @example
* ```ts twoslash
* import { Bytes, Rlp } from 'ox'
*
* Rlp.fromBytes(Bytes.from([139, 104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100]))
* // @log: Uint8Array([104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100])
* ```
*
* @param bytes - The {@link ox#Bytes.Bytes} value to encode.
* @param options - Options.
* @returns The RLP value.
*/
export function fromBytes(bytes, options = {}) {
const { as = 'Bytes' } = options;
return from(bytes, { as });
}
/**
* Encodes a {@link ox#Hex.Hex} value into a Recursive-Length Prefix (RLP) value.
*
* @example
* ```ts twoslash
* import { Rlp } from 'ox'
*
* Rlp.fromHex('0x68656c6c6f20776f726c64')
* // @log: 0x8b68656c6c6f20776f726c64
* ```
*
* @param hex - The {@link ox#Hex.Hex} value to encode.
* @param options - Options.
* @returns The RLP value.
*/
export function fromHex(hex, options = {}) {
const { as = 'Hex' } = options;
return from(hex, { as });
}
/////////////////////////////////////////////////////////////////////////////////
// Internal
/////////////////////////////////////////////////////////////////////////////////
function getEncodable(bytes) {
if (Array.isArray(bytes))
return getEncodableList(bytes.map((x) => getEncodable(x)));
return getEncodableBytes(bytes);
}
function getEncodableList(list) {
const bodyLength = list.reduce((acc, x) => acc + x.length, 0);
const sizeOfBodyLength = getSizeOfLength(bodyLength);
const length = (() => {
if (bodyLength <= 55)
return 1 + bodyLength;
return 1 + sizeOfBodyLength + bodyLength;
})();
return {
length,
encode(cursor) {
if (bodyLength <= 55) {
cursor.pushByte(0xc0 + bodyLength);
}
else {
cursor.pushByte(0xc0 + 55 + sizeOfBodyLength);
if (sizeOfBodyLength === 1)
cursor.pushUint8(bodyLength);
else if (sizeOfBodyLength === 2)
cursor.pushUint16(bodyLength);
else if (sizeOfBodyLength === 3)
cursor.pushUint24(bodyLength);
else
cursor.pushUint32(bodyLength);
}
for (const { encode } of list) {
encode(cursor);
}
},
};
}
function getEncodableBytes(bytesOrHex) {
const bytes = typeof bytesOrHex === 'string' ? Bytes.fromHex(bytesOrHex) : bytesOrHex;
const sizeOfBytesLength = getSizeOfLength(bytes.length);
const length = (() => {
if (bytes.length === 1 && bytes[0] < 0x80)
return 1;
if (bytes.length <= 55)
return 1 + bytes.length;
return 1 + sizeOfBytesLength + bytes.length;
})();
return {
length,
encode(cursor) {
if (bytes.length === 1 && bytes[0] < 0x80) {
cursor.pushBytes(bytes);
}
else if (bytes.length <= 55) {
cursor.pushByte(0x80 + bytes.length);
cursor.pushBytes(bytes);
}
else {
cursor.pushByte(0x80 + 55 + sizeOfBytesLength);
if (sizeOfBytesLength === 1)
cursor.pushUint8(bytes.length);
else if (sizeOfBytesLength === 2)
cursor.pushUint16(bytes.length);
else if (sizeOfBytesLength === 3)
cursor.pushUint24(bytes.length);
else
cursor.pushUint32(bytes.length);
cursor.pushBytes(bytes);
}
},
};
}
function getSizeOfLength(length) {
if (length < 2 ** 8)
return 1;
if (length < 2 ** 16)
return 2;
if (length < 2 ** 24)
return 3;
if (length < 2 ** 32)
return 4;
throw new Errors.BaseError('Length is too large.');
}
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