ext/web/14_compression.js - main - githubmirror/deno

ext/web/14_compression.js
190 строк5 KB
Bartek Iwańczuk
fix(ext/node): Node compat for web streams (#36285)
26 июл 2026, 12:39
26 июл 2026, 12:3939cc464
// Copyright 2018-2026 the Deno authors. MIT license.

// @ts-check
/// <reference path="../../core/lib.deno_core.d.ts" />
/// <reference path="./internal.d.ts" />
/// <reference path="../../cli/tsc/dts/lib.deno_web.d.ts" />

(function () {
const { core, primordials } = __bootstrap;
const {
  op_compression_finish,
  op_compression_new,
  op_compression_write,
} = core.ops;
const {
  SymbolFor,
  ObjectPrototypeIsPrototypeOf,
  TypeError,
  TypeErrorPrototype,
  TypedArrayPrototypeGetByteLength,
} = primordials;

const webidl = core.loadExtScript("ext:deno_webidl/00_webidl.js");
const { createFilteredInspectProxy } = core.loadExtScript(
  "ext:deno_web/01_console.js",
);
const { TransformStream } = core.loadExtScript("ext:deno_web/06_streams.js");

webidl.converters.CompressionFormat = webidl.createEnumConverter(
  "CompressionFormat",
  [
    "deflate",
    "deflate-raw",
    "gzip",
    "brotli",
  ],
);

// Convert a chunk to a BufferSource, attaching the Node.js-style error `code`
// that `node:stream/web` consumers rely on. `null` is reported specifically as
// `ERR_STREAM_NULL_VALUES`; any other non-BufferSource value fails the WebIDL
// conversion and is tagged `ERR_INVALID_ARG_TYPE`.
function convertChunk(chunk, prefix) {
  if (chunk === null) {
    const err = new TypeError("May not write null values to stream");
    err.code = "ERR_STREAM_NULL_VALUES";
    throw err;
  }
  try {
    return webidl.converters.BufferSource(chunk, prefix, "chunk");
  } catch (err) {
    if (ObjectPrototypeIsPrototypeOf(TypeErrorPrototype, err)) {
      err.code = "ERR_INVALID_ARG_TYPE";
    }
    throw err;
  }
}

class CompressionStream {
  #transform;

  constructor(format) {
    const prefix = "Failed to construct 'CompressionStream'";
    webidl.requiredArguments(arguments.length, 1, prefix);
    format = webidl.converters.CompressionFormat(format, prefix, "Argument 1");

    const rid = op_compression_new(format, false);

    this.#transform = new TransformStream({
      transform(chunk, controller) {
        chunk = convertChunk(chunk, prefix);
        const output = op_compression_write(
          rid,
          chunk,
        );
        maybeEnqueue(controller, output);
      },
      flush(controller) {
        const output = op_compression_finish(rid, true);
        maybeEnqueue(controller, output);
      },
      cancel: (_reason) => {
        op_compression_finish(rid, false);
      },
    });

    this[webidl.brand] = webidl.brand;
  }

  get readable() {
    webidl.assertBranded(this, CompressionStreamPrototype);
    return this.#transform.readable;
  }

  get writable() {
    webidl.assertBranded(this, CompressionStreamPrototype);
    return this.#transform.writable;
  }

  [SymbolFor("Deno.privateCustomInspect")](inspect, inspectOptions) {
    return inspect(
      createFilteredInspectProxy({
        object: this,
        evaluate: ObjectPrototypeIsPrototypeOf(
          CompressionStreamPrototype,
          this,
        ),
        keys: [
          "readable",
          "writable",
        ],
      }),
      inspectOptions,
    );
  }
}

webidl.configureInterface(CompressionStream);
const CompressionStreamPrototype = CompressionStream.prototype;

class DecompressionStream {
  #transform;

  constructor(format) {
    const prefix = "Failed to construct 'DecompressionStream'";
    webidl.requiredArguments(arguments.length, 1, prefix);
    format = webidl.converters.CompressionFormat(format, prefix, "Argument 1");

    const rid = op_compression_new(format, true);

    this.#transform = new TransformStream({
      transform(chunk, controller) {
        chunk = convertChunk(chunk, prefix);
        const output = op_compression_write(
          rid,
          chunk,
        );
        maybeEnqueue(controller, output);
      },
      flush(controller) {
        const output = op_compression_finish(rid, true);
        maybeEnqueue(controller, output);
      },
      cancel: (_reason) => {
        op_compression_finish(rid, false);
      },
    });

    this[webidl.brand] = webidl.brand;
  }

  get readable() {
    webidl.assertBranded(this, DecompressionStreamPrototype);
    return this.#transform.readable;
  }

  get writable() {
    webidl.assertBranded(this, DecompressionStreamPrototype);
    return this.#transform.writable;
  }

  [SymbolFor("Deno.privateCustomInspect")](inspect, inspectOptions) {
    return inspect(
      createFilteredInspectProxy({
        object: this,
        evaluate: ObjectPrototypeIsPrototypeOf(
          DecompressionStreamPrototype,
          this,
        ),
        keys: [
          "readable",
          "writable",
        ],
      }),
      inspectOptions,
    );
  }
}

function maybeEnqueue(controller, output) {
  if (output && TypedArrayPrototypeGetByteLength(output) > 0) {
    controller.enqueue(output);
  }
}

webidl.configureInterface(DecompressionStream);
const DecompressionStreamPrototype = DecompressionStream.prototype;

return { CompressionStream, DecompressionStream };
})();