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BREAKING(encoding): rename MaxVarInt to MaxVarint (#4896)

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Yoshiya Hinosawa 2024-05-30 18:16:48 +09:00 committed by GitHub
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commit 5a8fced2e1
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2 changed files with 20 additions and 20 deletions
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34
encoding/varint.ts
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@ -2,8 +2,8 @@
// Copyright 2020 Keith Cirkel. All rights reserved. MIT license.
// Copyright 2023 Skye "MierenManz". All rights reserved. MIT license.
/**
* Utilities for {@link https://protobuf.dev/programming-guides/encoding/#varints VarInt} encoding
* of typed integers. VarInt encoding represents integers using a variable number of bytes, with
* Utilities for {@link https://protobuf.dev/programming-guides/encoding/#varints Varint} encoding
* of typed integers. Varint encoding represents integers using a variable number of bytes, with
* smaller values requiring fewer bytes.
*
* ```ts
@ -35,13 +35,13 @@
export const MaxUint64 = 18446744073709551615n;
/**
* The maximum length, in bytes, of a VarInt encoded 64-bit integer.
* The maximum length, in bytes, of a Varint encoded 64-bit integer.
*/
export const MaxVarIntLen64 = 10;
export const MaxVarintLen64 = 10;
/**
* The maximum length, in bytes, of a VarInt encoded 32-bit integer.
* The maximum length, in bytes, of a Varint encoded 32-bit integer.
*/
export const MaxVarIntLen32 = 5;
export const MaxVarintLen32 = 5;
const MSB = 0x80;
const REST = 0x7f;
@ -56,7 +56,7 @@ const U64_VIEW = new BigUint64Array(AB);
/**
* Given a non empty `buf`, starting at `offset` (default: 0), begin decoding bytes as
* VarInt encoded bytes, for a maximum of 10 bytes (offset + 10). The returned
* Varint encoded bytes, for a maximum of 10 bytes (offset + 10). The returned
* tuple is of the decoded varint 32-bit number, and the new offset with which
* to continue decoding other data.
*
@ -64,7 +64,7 @@ const U64_VIEW = new BigUint64Array(AB);
* `number`, but this should only be used in cases where the varint is
* _assured_ to be 32-bits. If in doubt, use `decode()`.
*
* To know how many bytes the VarInt took to encode, simply negate `offset`
* To know how many bytes the Varint took to encode, simply negate `offset`
* from the returned new `offset`.
*
* @param buf The buffer to decode from.
@ -143,14 +143,14 @@ export function decodeVarint(buf: Uint8Array, offset = 0): [bigint, number] {
/**
* Given a `buf`, starting at `offset` (default: 0), begin decoding bytes as
* VarInt encoded bytes, for a maximum of 5 bytes (offset + 5). The returned
* Varint encoded bytes, for a maximum of 5 bytes (offset + 5). The returned
* tuple is of the decoded varint 32-bit number, and the new offset with which
* to continue decoding other data.
*
* VarInts are _not 32-bit by default_ so this should only be used in cases
* Varints are _not 32-bit by default_ so this should only be used in cases
* where the varint is _assured_ to be 32-bits. If in doubt, use `decode()`.
*
* To know how many bytes the VarInt took to encode, simply negate `offset`
* To know how many bytes the Varint took to encode, simply negate `offset`
* from the returned new `offset`.
*
* @param buf The buffer to decode from.
@ -171,7 +171,7 @@ export function decodeVarint32(buf: Uint8Array, offset = 0): [number, number] {
let decoded = 0;
for (
let i = offset;
i <= Math.min(buf.length, offset + MaxVarIntLen32);
i <= Math.min(buf.length, offset + MaxVarintLen32);
i += 1, shift += SHIFT
) {
const byte = buf[i]!;
@ -182,9 +182,9 @@ export function decodeVarint32(buf: Uint8Array, offset = 0): [number, number] {
}
/**
* Takes unsigned number `num` and converts it into a VarInt encoded
* Takes unsigned number `num` and converts it into a Varint encoded
* `Uint8Array`, returning a tuple consisting of a `Uint8Array` slice of the
* encoded VarInt, and an offset where the VarInt encoded bytes end within the
* encoded Varint, and an offset where the Varint encoded bytes end within the
* `Uint8Array`.
*
* If `buf` is not given then a Uint8Array will be created.
@ -197,7 +197,7 @@ export function decodeVarint32(buf: Uint8Array, offset = 0): [number, number] {
* @param num The number to encode.
* @param buf The buffer to write into.
* @param offset The offset to start writing at.
* @returns A tuple of the encoded VarInt `Uint8Array` and the new offset.
* @returns A tuple of the encoded Varint `Uint8Array` and the new offset.
*
* @example Usage
* ```ts
@ -210,14 +210,14 @@ export function decodeVarint32(buf: Uint8Array, offset = 0): [number, number] {
*/
export function encodeVarint(
num: bigint | number,
buf: Uint8Array = new Uint8Array(MaxVarIntLen64),
buf: Uint8Array = new Uint8Array(MaxVarintLen64),
offset = 0,
): [Uint8Array, number] {
num = BigInt(num);
if (num < 0n) throw new RangeError("signed input given");
for (
let i = offset;
i <= Math.min(buf.length, MaxVarIntLen64);
i <= Math.min(buf.length, MaxVarintLen64);
i += 1
) {
if (num < MSBN) {

6
encoding/varint_test.ts
View File

@ -8,11 +8,11 @@ import {
decodeVarint32,
encodeVarint,
MaxUint64,
MaxVarIntLen64,
MaxVarintLen64,
} from "./varint.ts";
function encodeDecode(i: number | bigint) {
const [buf, n] = encodeVarint(i, new Uint8Array(MaxVarIntLen64));
const [buf, n] = encodeVarint(i, new Uint8Array(MaxVarintLen64));
const fn = (typeof i === "bigint") ? decodeVarint : decodeVarint32;
const [j, m] = fn(buf);
assertEquals(i, j, `${fn.name}(encodeVarint(${i})): ${i} !== ${j}`);
@ -123,7 +123,7 @@ Deno.test("encodeVarint() encodes with offset", () => {
[Uint8Array.of(172, 2), 3],
);
assertEquals(uint, Uint8Array.of(0, 172, 2));
uint = new Uint8Array(MaxVarIntLen64);
uint = new Uint8Array(MaxVarintLen64);
uint[0] = uint[1] = uint[2] = 12;
assertEquals(
encodeVarint(4294967295, uint, 3),