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export function readUint8(buffer: Uint8Array, index: number) {
return buffer[index];
}
export function readUint16(buffer: Uint8Array, index: number) {
return (buffer[index] << 8) + buffer[index + 1];
}
export function readUint24(buffer: Uint8Array, index: number) {
return (buffer[index] << 16) + (buffer[index + 1] << 8) + buffer[index + 2];
}
export function readUint32(buffer: Uint8Array, index: number) {
return ((buffer[index] << 24) + (buffer[index + 1] << 16) + (buffer[index + 2] << 8) + buffer[index + 3]) >>> 0;
}
export function readUint64(buffer: Uint8Array, index: number) {
const left = readUint32(buffer, index);
const right = readUint32(buffer, index+4);
return (BigInt(left) << 32n) + BigInt(right);
}
export function readUintN(buffer: Uint8Array, index: number, n: number) {
switch (n) {
case 1: return readUint8(buffer, index);
case 2: return readUint16(buffer, index);
case 3: return readUint24(buffer, index);
case 4: return readUint32(buffer, index);
default: throw new Error('Unsupported UInt size');
}
}
export function writeUint8(uint: number, buffer: Uint8Array, index: number) {
buffer[index] = uint & 255;
}
export function writeUint16(uint: number, buffer: Uint8Array, index: number) {
buffer[index] = (uint & 65280) >> 8;
buffer[index + 1] = uint & 255;
}
export function writeUint24(uint: number, buffer: Uint8Array, index: number) {
buffer[index] = (uint & 16711680) >> 16;
buffer[index + 1] = (uint & 65280) >> 8;
buffer[index + 2] = uint & 255;
}
export function writeUint32(uint: number, buffer: Uint8Array, index: number) {
buffer[index] = (uint & 4278190080) >> 24;
buffer[index + 1] = (uint & 16711680) >> 16;
buffer[index + 2] = (uint & 65280) >> 8;
buffer[index + 3] = uint & 255;
}
export function writeUint64(uint: bigint, buffer: Uint8Array, index: number) {
const left = (uint & 0xffffffff00000000n) >> 32n;
const right = uint & 0xffffffffn;
writeUint32(Number(left), buffer, index);
writeUint32(Number(right), buffer, index+4);
}
export function writeUintN(uint: number, buffer: Uint8Array, index: number, size: number) {
switch (size) {
case 1: return writeUint8(uint, buffer, index);
case 2: return writeUint16(uint, buffer, index);
case 3: return writeUint24(uint, buffer, index);
case 4: return writeUint32(uint, buffer, index);
default: throw new Error('Unsupported UInt size');
}
}
export function minUInt(uint: number) {
if (uint < 256) return 1;
if (uint < 65536) return 2;
if (uint < 16777216) return 3;
if (uint < 4294967296) return 4;
throw new Error('Unsupported UInt size');
}
export function concatUint8Array(arrays: Uint8Array[]): Uint8Array {
let size = 0;
for (const array of arrays) {
size += array.length;
}
const buffer = new Uint8Array(size);
let index = 0;
for (const array of arrays) {
buffer.set(array, index);
index += array.length;
}
return buffer;
}
const decoder = new TextDecoder('utf8');
const encoder = new TextEncoder();
export function readString(buffer: Uint8Array, index: number, length: number) {
return decoder.decode(buffer.subarray(index, index+length));
}
export function writeString(str: string, buffer: Uint8Array, index: number) {
buffer.set(encoder.encode(str), index);
}
export function encodeString(str: string) {
return encoder.encode(str);
}
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