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// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
import { core, primordials } from "ext:core/mod.js";
const {
Uint8Array,
Number,
PromisePrototypeThen,
PromisePrototypeCatch,
ObjectEntries,
ArrayPrototypeMap,
TypedArrayPrototypeSlice,
TypedArrayPrototypeSubarray,
TypedArrayPrototypeGetByteLength,
DataViewPrototypeGetBuffer,
TypedArrayPrototypeGetBuffer,
} = primordials;
const { isTypedArray, isDataView, close } = core;
import {
op_brotli_compress,
op_brotli_compress_async,
op_brotli_compress_stream,
op_brotli_compress_stream_end,
op_brotli_decompress,
op_brotli_decompress_async,
op_brotli_decompress_stream,
op_brotli_decompress_stream_end,
op_create_brotli_compress,
op_create_brotli_decompress,
} from "ext:core/ops";
import { zlib as constants } from "ext:deno_node/internal_binding/constants.ts";
import { TextEncoder } from "ext:deno_web/08_text_encoding.js";
import { Transform } from "node:stream";
import { Buffer } from "node:buffer";
const enc = new TextEncoder();
const toU8 = (input) => {
if (typeof input === "string") {
return enc.encode(input);
}
if (isTypedArray(input)) {
return new Uint8Array(TypedArrayPrototypeGetBuffer(input));
} else if (isDataView(input)) {
return new Uint8Array(DataViewPrototypeGetBuffer(input));
}
return input;
};
export function createBrotliCompress(options) {
return new BrotliCompress(options);
}
export function createBrotliDecompress(options) {
return new BrotliDecompress(options);
}
export class BrotliDecompress extends Transform {
#context;
// TODO(littledivy): use `options` argument
constructor(_options = { __proto__: null }) {
super({
// TODO(littledivy): use `encoding` argument
transform(chunk, _encoding, callback) {
const input = toU8(chunk);
const output = new Uint8Array(TypedArrayPrototypeGetByteLength(chunk));
const avail = op_brotli_decompress_stream(context, input, output);
// deno-lint-ignore prefer-primordials
this.push(TypedArrayPrototypeSlice(output, 0, avail));
callback();
},
flush(callback) {
const output = new Uint8Array(1024);
let avail;
while ((avail = op_brotli_decompress_stream_end(context, output)) > 0) {
// deno-lint-ignore prefer-primordials
this.push(TypedArrayPrototypeSlice(output, 0, avail));
}
close(context);
callback();
},
});
this.#context = op_create_brotli_decompress();
const context = this.#context;
}
}
export class BrotliCompress extends Transform {
#context;
constructor(options = { __proto__: null }) {
super({
// TODO(littledivy): use `encoding` argument
transform(chunk, _encoding, callback) {
const input = toU8(chunk);
const output = new Uint8Array(brotliMaxCompressedSize(input.length));
const written = op_brotli_compress_stream(context, input, output);
if (written > 0) {
// deno-lint-ignore prefer-primordials
this.push(TypedArrayPrototypeSlice(output, 0, written));
}
callback();
},
flush(callback) {
const output = new Uint8Array(1024);
let avail;
while ((avail = op_brotli_compress_stream_end(context, output)) > 0) {
// deno-lint-ignore prefer-primordials
this.push(TypedArrayPrototypeSlice(output, 0, avail));
}
close(context);
callback();
},
});
const params = ArrayPrototypeMap(
ObjectEntries(options?.params ?? {}),
// Undo the stringification of the keys
(o) => [Number(o[0]), o[1]],
);
this.#context = op_create_brotli_compress(params);
const context = this.#context;
}
}
function oneOffCompressOptions(options) {
let quality = options?.params?.[constants.BROTLI_PARAM_QUALITY] ??
constants.BROTLI_DEFAULT_QUALITY;
const lgwin = options?.params?.[constants.BROTLI_PARAM_LGWIN] ??
constants.BROTLI_DEFAULT_WINDOW;
const mode = options?.params?.[constants.BROTLI_PARAM_MODE] ??
constants.BROTLI_MODE_GENERIC;
// NOTE(bartlomieju): currently the rust-brotli crate panics if the quality
// is set to 10. Coerce it down to 9.5 which is the maximum supported value.
// https://github.com/dropbox/rust-brotli/issues/216
if (quality == 10) {
quality = 9.5;
}
return {
quality,
lgwin,
mode,
};
}
function brotliMaxCompressedSize(input) {
if (input == 0) return 2;
// [window bits / empty metadata] + N * [uncompressed] + [last empty]
const numLargeBlocks = input >> 24;
const overhead = 2 + (4 * numLargeBlocks) + 3 + 1;
const result = input + overhead;
return result < input ? 0 : result;
}
export function brotliCompress(
input,
options,
callback,
) {
const buf = toU8(input);
if (typeof options === "function") {
callback = options;
options = {};
}
const { quality, lgwin, mode } = oneOffCompressOptions(options);
PromisePrototypeCatch(
PromisePrototypeThen(
op_brotli_compress_async(buf, quality, lgwin, mode),
(result) => callback(null, Buffer.from(result)),
),
(err) => callback(err),
);
}
export function brotliCompressSync(
input,
options,
) {
const buf = toU8(input);
const output = new Uint8Array(brotliMaxCompressedSize(buf.length));
const { quality, lgwin, mode } = oneOffCompressOptions(options);
const len = op_brotli_compress(buf, output, quality, lgwin, mode);
return Buffer.from(TypedArrayPrototypeSubarray(output, 0, len));
}
export function brotliDecompress(input) {
const buf = toU8(input);
return PromisePrototypeCatch(
PromisePrototypeThen(
op_brotli_decompress_async(buf),
(result) => callback(null, Buffer.from(result)),
),
(err) => callback(err),
);
}
export function brotliDecompressSync(input) {
return Buffer.from(op_brotli_decompress(toU8(input)));
}
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