streams: add CompressionStream and DecompressionStream

Signed-off-by: James M Snell <[email protected]>

Author: jasnell

doc/api/webstreams.md

@@ -1118,5 +1118,57 @@ added: REPLACEME
   * `chunk` {any}
   * Returns: {number}
 
+### Class: `CompressionStream`
+<!-- YAML
+added: REPLACEME
+-->
+
+#### `new CompressionStream(format)`
+<!-- YAML
+added: REPLACEME
+-->
+
+* `format` {string} One of either `'deflate'` or `'gzip'`.
+
+#### `compressionStream.readable`
+<!-- YAML
+added: REPLACEME
+-->
+
+* Type: {ReadableStream}
+
+#### `compressionStream.writable`
+<!-- YAML
+added: REPLACEME
+-->
+
+* Type: {WritableStream}
+
+### Class: `DecompressionStream`
+<!-- YAML
+added: REPLACEME
+-->
+
+#### `new DecompressionStream(format)`
+<!-- YAML
+added: REPLACEME
+-->
+
+* `format` {string} One of either `'deflate'` or `'gzip'`.
+
+#### `decompressionStream.readable`
+<!-- YAML
+added: REPLACEME
+-->
+
+* Type: {ReadableStream}
+
+#### `deccompressionStream.writable`
+<!-- YAML
+added: REPLACEME
+-->
+
+* Type: {WritableStream}
+
 [Streams]: stream.md
 [WHATWG Streams Standard]: https://streams.spec.whatwg.org/

lib/internal/webstreams/compression.js

@@ -0,0 +1,164 @@
+'use strict';
+
+const {
+  ObjectDefineProperties,
+  Symbol,
+} = primordials;
+
+const {
+  codes: {
+    ERR_INVALID_ARG_VALUE,
+    ERR_INVALID_THIS,
+  },
+} = require('internal/errors');
+
+const {
+  newReadableWritablePairFromDuplex,
+} = require('internal/webstreams/adapters');
+
+const {
+  customInspect,
+} = require('internal/webstreams/util');
+
+const {
+  customInspectSymbol: kInspect,
+} = require('internal/util');
+
+const {
+  createDeflate,
+  createInflate,
+  createGzip,
+  createGunzip,
+} = require('zlib');
+
+const kHandle = Symbol('kHandle');
+const kTransform = Symbol('kTransform');
+const kType = Symbol('kType');
+
+/**
+ * @typedef {import('./readablestream').ReadableStream} ReadableStream
+ * @typedef {import('./writablestream').WritableStream} WritableStream
+ */
+
+function isCompressionStream(value) {
+  return typeof value?.[kHandle] === 'object' &&
+         value?.[kType] === 'CompressionStream';
+}
+
+function isDecompressionStream(value) {
+  return typeof value?.[kHandle] === 'object' &&
+         value?.[kType] === 'DecompressionStream';
+}
+
+class CompressionStream {
+  /**
+   * @param {'deflate'|'gzip'} format
+   */
+  constructor(format) {
+    this[kType] = 'CompressionStream';
+    switch (format) {
+      case 'deflate':
+        this[kHandle] = createDeflate();
+        break;
+      case 'gzip':
+        this[kHandle] = createGzip();
+        break;
+      default:
+        throw new ERR_INVALID_ARG_VALUE('format', format);
+    }
+    this[kTransform] = newReadableWritablePairFromDuplex(this[kHandle]);
+  }
+
+  /**
+   * @readonly
+   * @type {ReadableStream}
+   */
+  get readable() {
+    if (!isCompressionStream(this))
+      throw new ERR_INVALID_THIS('CompressionStream');
+    return this[kTransform].readable;
+  }
+
+  /**
+   * @readonly
+   * @type {WritableStream}
+   */
+  get writable() {
+    if (!isCompressionStream(this))
+      throw new ERR_INVALID_THIS('CompressionStream');
+    return this[kTransform].writable;
+  }
+
+  [kInspect](depth, options) {
+    if (!isCompressionStream(this))
+      throw new ERR_INVALID_THIS('CompressionStream');
+    customInspect(depth, options, 'CompressionStream', {
+      readable: this[kTransform].readable,
+      writable: this[kTransform].writable,
+    });
+  }
+}
+
+class DecompressionStream {
+  /**
+   * @param {'deflate'|'gzip'} format
+   */
+  constructor(format) {
+    this[kType] = 'DecompressionStream';
+    switch (format) {
+      case 'deflate':
+        this[kHandle] = createInflate();
+        break;
+      case 'gzip':
+        this[kHandle] = createGunzip();
+        break;
+      default:
+        throw new ERR_INVALID_ARG_VALUE('format', format);
+    }
+    this[kTransform] = newReadableWritablePairFromDuplex(this[kHandle]);
+  }
+
+  /**
+   * @readonly
+   * @type {ReadableStream}
+   */
+  get readable() {
+    if (!isDecompressionStream(this))
+      throw new ERR_INVALID_THIS('DecompressionStream');
+    return this[kTransform].readable;
+  }
+
+  /**
+   * @readonly
+   * @type {WritableStream}
+   */
+  get writable() {
+    if (!isDecompressionStream(this))
+      throw new ERR_INVALID_THIS('DecompressionStream');
+    return this[kTransform].writable;
+  }
+
+  [kInspect](depth, options) {
+    if (!isDecompressionStream(this))
+      throw new ERR_INVALID_THIS('DecompressionStream');
+    customInspect(depth, options, 'DecompressionStream', {
+      readable: this[kTransform].readable,
+      writable: this[kTransform].writable,
+    });
+  }
+}
+
+ObjectDefineProperties(CompressionStream.prototype, {
+  readable: { enumerable: true },
+  writable: { enumerable: true },
+});
+
+ObjectDefineProperties(DecompressionStream.prototype, {
+  readable: { enumerable: true },
+  writable: { enumerable: true },
+});
+
+module.exports = {
+  CompressionStream,
+  DecompressionStream,
+};

lib/stream/web.js

@@ -31,6 +31,11 @@ const {
   CountQueuingStrategy,
 } = require('internal/webstreams/queuingstrategies');
 
+const {
+  CompressionStream,
+  DecompressionStream,
+} = require('internal/webstreams/compression');
+
 module.exports = {
   ReadableStream,
   ReadableStreamDefaultReader,
@@ -45,4 +50,6 @@ module.exports = {
   WritableStreamDefaultController,
   ByteLengthQueuingStrategy,
   CountQueuingStrategy,
+  CompressionStream,
+  DecompressionStream,
 };

test/parallel/test-whatwg-webstreams-compression.js

@@ -0,0 +1,59 @@
+// Flags: --expose-internals --no-warnings
+'use strict';
+
+const common = require('../common');
+
+const {
+  CompressionStream,
+  DecompressionStream,
+} = require('internal/webstreams/compression');
+
+const assert = require('assert');
+const dec = new TextDecoder();
+
+async function test(format) {
+  const gzip = new CompressionStream(format);
+  const gunzip = new DecompressionStream(format);
+
+  gzip.readable.pipeTo(gunzip.writable).then(common.mustCall());
+
+  const reader = gunzip.readable.getReader();
+  const writer = gzip.writable.getWriter();
+
+  await Promise.all([
+    reader.read().then(({ value, done }) => {
+      assert.strictEqual(dec.decode(value), 'hello');
+    }),
+    reader.read().then(({ done }) => assert(done)),
+    writer.write('hello'),
+    writer.close(),
+  ]);
+}
+
+Promise.all(['gzip', 'deflate'].map((i) => test(i))).then(common.mustCall());
+
+[1, 'hello', false, {}].forEach((i) => {
+  assert.throws(() => new CompressionStream(i), {
+    code: 'ERR_INVALID_ARG_VALUE',
+  });
+  assert.throws(() => new DecompressionStream(i), {
+    code: 'ERR_INVALID_ARG_VALUE',
+  });
+});
+
+assert.throws(
+  () => Reflect.get(CompressionStream.prototype, 'readable', {}), {
+    code: 'ERR_INVALID_THIS',
+  });
+assert.throws(
+  () => Reflect.get(CompressionStream.prototype, 'writable', {}), {
+    code: 'ERR_INVALID_THIS',
+  });
+assert.throws(
+  () => Reflect.get(DecompressionStream.prototype, 'readable', {}), {
+    code: 'ERR_INVALID_THIS',
+  });
+assert.throws(
+  () => Reflect.get(DecompressionStream.prototype, 'writable', {}), {
+    code: 'ERR_INVALID_THIS',
+  });