ts • Lines: 564import { BufferBuilder } from "./bufferbuilder";
export type Packable =
| null
| undefined
| string
| number
| boolean
| Date
| ArrayBuffer
| Blob
| Array<Packable>
| { [key: string]: Packable }
| ({ BYTES_PER_ELEMENT: number } & ArrayBufferView);
export type Unpackable =
| null
| undefined
| string
| number
| boolean
| ArrayBuffer
| Array<Unpackable>
| { [key: string]: Unpackable };
export function unpack<T extends Unpackable>(data: ArrayBuffer) {
const unpacker = new Unpacker(data);
return unpacker.unpack() as T;
}
export function pack(data: Packable) {
const packer = new Packer();
const res = packer.pack(data);
if (res instanceof Promise) {
return res.then(() => packer.getBuffer());
}
return packer.getBuffer();
}
class Unpacker {
private index: number;
private readonly dataBuffer: ArrayBuffer;
private readonly dataView: Uint8Array;
private readonly length: number;
constructor(data: ArrayBuffer) {
this.index = 0;
this.dataBuffer = data;
this.dataView = new Uint8Array(this.dataBuffer);
this.length = this.dataBuffer.byteLength;
}
unpack(): Unpackable {
const type = this.unpack_uint8();
if (type < 0x80) {
return type;
} else if ((type ^ 0xe0) < 0x20) {
return (type ^ 0xe0) - 0x20;
}
let size;
if ((size = type ^ 0xa0) <= 0x0f) {
return this.unpack_raw(size);
} else if ((size = type ^ 0xb0) <= 0x0f) {
return this.unpack_string(size);
} else if ((size = type ^ 0x90) <= 0x0f) {
return this.unpack_array(size);
} else if ((size = type ^ 0x80) <= 0x0f) {
return this.unpack_map(size);
}
switch (type) {
case 0xc0:
return null;
case 0xc1:
return undefined;
case 0xc2:
return false;
case 0xc3:
return true;
case 0xca:
return this.unpack_float();
case 0xcb:
return this.unpack_double();
case 0xcc:
return this.unpack_uint8();
case 0xcd:
return this.unpack_uint16();
case 0xce:
return this.unpack_uint32();
case 0xcf:
return this.unpack_uint64();
case 0xd0:
return this.unpack_int8();
case 0xd1:
return this.unpack_int16();
case 0xd2:
return this.unpack_int32();
case 0xd3:
return this.unpack_int64();
case 0xd4:
return undefined;
case 0xd5:
return undefined;
case 0xd6:
return undefined;
case 0xd7:
return undefined;
case 0xd8:
size = this.unpack_uint16();
return this.unpack_string(size);
case 0xd9:
size = this.unpack_uint32();
return this.unpack_string(size);
case 0xda:
size = this.unpack_uint16();
return this.unpack_raw(size);
case 0xdb:
size = this.unpack_uint32();
return this.unpack_raw(size);
case 0xdc:
size = this.unpack_uint16();
return this.unpack_array(size);
case 0xdd:
size = this.unpack_uint32();
return this.unpack_array(size);
case 0xde:
size = this.unpack_uint16();
return this.unpack_map(size);
case 0xdf:
size = this.unpack_uint32();
return this.unpack_map(size);
}
}
unpack_uint8() {
const byte = this.dataView[this.index] & 0xff;
this.index++;
return byte;
}
unpack_uint16() {
const bytes = this.read(2);
const uint16 = (bytes[0] & 0xff) * 256 + (bytes[1] & 0xff);
this.index += 2;
return uint16;
}
unpack_uint32() {
const bytes = this.read(4);
const uint32 =
((bytes[0] * 256 + bytes[1]) * 256 + bytes[2]) * 256 + bytes[3];
this.index += 4;
return uint32;
}
unpack_uint64() {
const bytes = this.read(8);
const uint64 =
((((((bytes[0] * 256 + bytes[1]) * 256 + bytes[2]) * 256 + bytes[3]) *
256 +
bytes[4]) *
256 +
bytes[5]) *
256 +
bytes[6]) *
256 +
bytes[7];
this.index += 8;
return uint64;
}
unpack_int8() {
const uint8 = this.unpack_uint8();
return uint8 < 0x80 ? uint8 : uint8 - (1 << 8);
}
unpack_int16() {
const uint16 = this.unpack_uint16();
return uint16 < 0x8000 ? uint16 : uint16 - (1 << 16);
}
unpack_int32() {
const uint32 = this.unpack_uint32();
return uint32 < 2 ** 31 ? uint32 : uint32 - 2 ** 32;
}
unpack_int64() {
const uint64 = this.unpack_uint64();
return uint64 < 2 ** 63 ? uint64 : uint64 - 2 ** 64;
}
unpack_raw(size: number) {
if (this.length < this.index + size) {
throw new Error(
`BinaryPackFailure: index is out of range ${this.index} ${size} ${this.length}`,
);
}
const buf = this.dataBuffer.slice(this.index, this.index + size);
this.index += size;
return buf;
}
unpack_string(size: number) {
const bytes = this.read(size);
let i = 0;
let str = "";
let c;
let code;
while (i < size) {
c = bytes[i];
// The length of a UTF-8 sequence is specified in the first byte:
// 0xxxxxxx means length 1,
// 110xxxxx means length 2,
// 1110xxxx means length 3,
// 11110xxx means length 4.
// 10xxxxxx is for non-initial bytes.
if (c < 0xa0) {
// One-byte sequence: bits 0xxxxxxx
code = c;
i++;
} else if ((c ^ 0xc0) < 0x20) {
// Two-byte sequence: bits 110xxxxx 10xxxxxx
code = ((c & 0x1f) << 6) | (bytes[i + 1] & 0x3f);
i += 2;
} else if ((c ^ 0xe0) < 0x10) {
// Three-byte sequence: bits 1110xxxx 10xxxxxx 10xxxxxx
code =
((c & 0x0f) << 12) |
((bytes[i + 1] & 0x3f) << 6) |
(bytes[i + 2] & 0x3f);
i += 3;
} else {
// Four-byte sequence: bits 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
code =
((c & 0x07) << 18) |
((bytes[i + 1] & 0x3f) << 12) |
((bytes[i + 2] & 0x3f) << 6) |
(bytes[i + 3] & 0x3f);
i += 4;
}
str += String.fromCodePoint(code);
}
this.index += size;
return str;
}
unpack_array(size: number) {
const objects = new Array<Unpackable>(size);
for (let i = 0; i < size; i++) {
objects[i] = this.unpack();
}
return objects;
}
unpack_map(size: number) {
const map: { [key: string]: Unpackable } = {};
for (let i = 0; i < size; i++) {
const key = this.unpack() as string;
map[key] = this.unpack();
}
return map;
}
unpack_float() {
const uint32 = this.unpack_uint32();
const sign = uint32 >> 31;
const exp = ((uint32 >> 23) & 0xff) - 127;
const fraction = (uint32 & 0x7fffff) | 0x800000;
return (sign === 0 ? 1 : -1) * fraction * 2 ** (exp - 23);
}
unpack_double() {
const h32 = this.unpack_uint32();
const l32 = this.unpack_uint32();
const sign = h32 >> 31;
const exp = ((h32 >> 20) & 0x7ff) - 1023;
const hfrac = (h32 & 0xfffff) | 0x100000;
const frac = hfrac * 2 ** (exp - 20) + l32 * 2 ** (exp - 52);
return (sign === 0 ? 1 : -1) * frac;
}
read(length: number) {
const j = this.index;
if (j + length <= this.length) {
return this.dataView.subarray(j, j + length);
} else {
throw new Error("BinaryPackFailure: read index out of range");
}
}
}
export class Packer {
private _bufferBuilder = new BufferBuilder();
private _textEncoder = new TextEncoder();
getBuffer() {
return this._bufferBuilder.toArrayBuffer();
}
pack(value: Packable) {
if (typeof value === "string") {
this.pack_string(value);
} else if (typeof value === "number") {
if (Math.floor(value) === value) {
this.pack_integer(value);
} else {
this.pack_double(value);
}
} else if (typeof value === "boolean") {
if (value === true) {
this._bufferBuilder.append(0xc3);
} else if (value === false) {
this._bufferBuilder.append(0xc2);
}
} else if (value === undefined) {
this._bufferBuilder.append(0xc0);
} else if (typeof value === "object") {
if (value === null) {
this._bufferBuilder.append(0xc0);
} else {
const constructor = value.constructor;
if (value instanceof Array) {
const res = this.pack_array(value);
if (res instanceof Promise) {
return res.then(() => this._bufferBuilder.flush());
}
} else if (value instanceof ArrayBuffer) {
this.pack_bin(new Uint8Array(value));
} else if ("BYTES_PER_ELEMENT" in value) {
const v = value as unknown as DataView;
this.pack_bin(new Uint8Array(v.buffer, v.byteOffset, v.byteLength));
} else if (value instanceof Date) {
this.pack_string(value.toString());
} else if (value instanceof Blob) {
return value.arrayBuffer().then((buffer) => {
this.pack_bin(new Uint8Array(buffer));
this._bufferBuilder.flush();
});
// this.pack_bin(new Uint8Array(await value.arrayBuffer()));
} else if (
constructor == Object ||
constructor.toString().startsWith("class")
) {
const res = this.pack_object(value);
if (res instanceof Promise) {
return res.then(() => this._bufferBuilder.flush());
}
} else {
throw new Error(`Type "${constructor.toString()}" not yet supported`);
}
}
} else {
throw new Error(`Type "${typeof value}" not yet supported`);
}
this._bufferBuilder.flush();
}
pack_bin(blob: Uint8Array) {
const length = blob.length;
if (length <= 0x0f) {
this.pack_uint8(0xa0 + length);
} else if (length <= 0xffff) {
this._bufferBuilder.append(0xda);
this.pack_uint16(length);
} else if (length <= 0xffffffff) {
this._bufferBuilder.append(0xdb);
this.pack_uint32(length);
} else {
throw new Error("Invalid length");
}
this._bufferBuilder.append_buffer(blob);
}
pack_string(str: string) {
const encoded = this._textEncoder.encode(str);
const length = encoded.length;
if (length <= 0x0f) {
this.pack_uint8(0xb0 + length);
} else if (length <= 0xffff) {
this._bufferBuilder.append(0xd8);
this.pack_uint16(length);
} else if (length <= 0xffffffff) {
this._bufferBuilder.append(0xd9);
this.pack_uint32(length);
} else {
throw new Error("Invalid length");
}
this._bufferBuilder.append_buffer(encoded);
}
pack_array(ary: Packable[]) {
const length = ary.length;
if (length <= 0x0f) {
this.pack_uint8(0x90 + length);
} else if (length <= 0xffff) {
this._bufferBuilder.append(0xdc);
this.pack_uint16(length);
} else if (length <= 0xffffffff) {
this._bufferBuilder.append(0xdd);
this.pack_uint32(length);
} else {
throw new Error("Invalid length");
}
const packNext = (index: number): Promise<void> | void => {
if (index < length) {
const res = this.pack(ary[index]);
if (res instanceof Promise) {
return res.then(() => packNext(index + 1));
}
return packNext(index + 1);
}
};
return packNext(0);
}
pack_integer(num: number) {
if (num >= -0x20 && num <= 0x7f) {
this._bufferBuilder.append(num & 0xff);
} else if (num >= 0x00 && num <= 0xff) {
this._bufferBuilder.append(0xcc);
this.pack_uint8(num);
} else if (num >= -0x80 && num <= 0x7f) {
this._bufferBuilder.append(0xd0);
this.pack_int8(num);
} else if (num >= 0x0000 && num <= 0xffff) {
this._bufferBuilder.append(0xcd);
this.pack_uint16(num);
} else if (num >= -0x8000 && num <= 0x7fff) {
this._bufferBuilder.append(0xd1);
this.pack_int16(num);
} else if (num >= 0x00000000 && num <= 0xffffffff) {
this._bufferBuilder.append(0xce);
this.pack_uint32(num);
} else if (num >= -0x80000000 && num <= 0x7fffffff) {
this._bufferBuilder.append(0xd2);
this.pack_int32(num);
} else if (num >= -0x8000000000000000 && num <= 0x7fffffffffffffff) {
this._bufferBuilder.append(0xd3);
this.pack_int64(num);
} else if (num >= 0x0000000000000000 && num <= 0xffffffffffffffff) {
this._bufferBuilder.append(0xcf);
this.pack_uint64(num);
} else {
throw new Error("Invalid integer");
}
}
pack_double(num: number) {
let sign = 0;
if (num < 0) {
sign = 1;
num = -num;
}
const exp = Math.floor(Math.log(num) / Math.LN2);
const frac0 = num / 2 ** exp - 1;
const frac1 = Math.floor(frac0 * 2 ** 52);
const b32 = 2 ** 32;
const h32 =
(sign << 31) | ((exp + 1023) << 20) | ((frac1 / b32) & 0x0fffff);
const l32 = frac1 % b32;
this._bufferBuilder.append(0xcb);
this.pack_int32(h32);
this.pack_int32(l32);
}
pack_object(obj: { [key: string]: Packable }) {
const keys = Object.keys(obj);
const length = keys.length;
if (length <= 0x0f) {
this.pack_uint8(0x80 + length);
} else if (length <= 0xffff) {
this._bufferBuilder.append(0xde);
this.pack_uint16(length);
} else if (length <= 0xffffffff) {
this._bufferBuilder.append(0xdf);
this.pack_uint32(length);
} else {
throw new Error("Invalid length");
}
const packNext = (index: number): Promise<void> | void => {
if (index < keys.length) {
const prop = keys[index];
// eslint-disable-next-line no-prototype-builtins
if (obj.hasOwnProperty(prop)) {
this.pack(prop);
const res = this.pack(obj[prop]);
if (res instanceof Promise) {
return res.then(() => packNext(index + 1));
}
}
return packNext(index + 1);
}
};
return packNext(0);
}
pack_uint8(num: number) {
this._bufferBuilder.append(num);
}
pack_uint16(num: number) {
this._bufferBuilder.append(num >> 8);
this._bufferBuilder.append(num & 0xff);
}
pack_uint32(num: number) {
const n = num & 0xffffffff;
this._bufferBuilder.append((n & 0xff000000) >>> 24);
this._bufferBuilder.append((n & 0x00ff0000) >>> 16);
this._bufferBuilder.append((n & 0x0000ff00) >>> 8);
this._bufferBuilder.append(n & 0x000000ff);
}
pack_uint64(num: number) {
const high = num / 2 ** 32;
const low = num % 2 ** 32;
this._bufferBuilder.append((high & 0xff000000) >>> 24);
this._bufferBuilder.append((high & 0x00ff0000) >>> 16);
this._bufferBuilder.append((high & 0x0000ff00) >>> 8);
this._bufferBuilder.append(high & 0x000000ff);
this._bufferBuilder.append((low & 0xff000000) >>> 24);
this._bufferBuilder.append((low & 0x00ff0000) >>> 16);
this._bufferBuilder.append((low & 0x0000ff00) >>> 8);
this._bufferBuilder.append(low & 0x000000ff);
}
pack_int8(num: number) {
this._bufferBuilder.append(num & 0xff);
}
pack_int16(num: number) {
this._bufferBuilder.append((num & 0xff00) >> 8);
this._bufferBuilder.append(num & 0xff);
}
pack_int32(num: number) {
this._bufferBuilder.append((num >>> 24) & 0xff);
this._bufferBuilder.append((num & 0x00ff0000) >>> 16);
this._bufferBuilder.append((num & 0x0000ff00) >>> 8);
this._bufferBuilder.append(num & 0x000000ff);
}
pack_int64(num: number) {
const high = Math.floor(num / 2 ** 32);
const low = num % 2 ** 32;
this._bufferBuilder.append((high & 0xff000000) >>> 24);
this._bufferBuilder.append((high & 0x00ff0000) >>> 16);
this._bufferBuilder.append((high & 0x0000ff00) >>> 8);
this._bufferBuilder.append(high & 0x000000ff);
this._bufferBuilder.append((low & 0xff000000) >>> 24);
this._bufferBuilder.append((low & 0x00ff0000) >>> 16);
this._bufferBuilder.append((low & 0x0000ff00) >>> 8);
this._bufferBuilder.append(low & 0x000000ff);
}
}