Make CompressionStream native

packages/bun-types/bun.d.ts

@@ -262,6 +262,10 @@ declare module "bun" {
     unref(): void;
   }
 
+  interface TransformerCancelCallback {
+    (reason: any): void | PromiseLike<void>;
+  }
+
   interface TransformerFlushCallback<O> {
     (controller: TransformStreamDefaultController<O>): void | PromiseLike<void>;
   }

packages/bun-types/globals.d.ts

@@ -868,6 +868,7 @@ interface QueuingStrategySize<T = any> {
 }
 
 interface Transformer<I = any, O = any> {
+  cancel?: Bun.TransformerCancelCallback;
   flush?: Bun.TransformerFlushCallback<O>;
   readableType?: undefined;
   start?: Bun.TransformerStartCallback<O>;

src/js/builtins/BunBuiltinNames.h

@@ -24,6 +24,7 @@ using namespace JSC;
 #define BUN_COMMON_PRIVATE_IDENTIFIERS_EACH_PROPERTY_NAME(macro) \
     macro(AbortSignal) \
     macro(Buffer) \
+    macro(CompressionStreamTransformer) \
     macro(Loader) \
     macro(ReadableByteStreamController) \
     macro(ReadableStream) \
@@ -99,6 +100,7 @@ using namespace JSC;
     macro(fatal) \
     macro(fd) \
     macro(filename) \
+    macro(finishPromise) \
     macro(flushAlgorithm) \
     macro(format) \
     macro(fulfillModuleSync) \

src/js/builtins/CompressionStream.ts

@@ -1,21 +1,24 @@
 export function initializeCompressionStream(this, format) {
-  const zlib = require("node:zlib");
-  const { newBufferSourceTransformPairFromDuplex } = require("internal/webstreams_adapters");
-
-  const builders = {
-    "deflate": zlib.createDeflate,
-    "deflate-raw": zlib.createDeflateRaw,
-    "gzip": zlib.createGzip,
-    "brotli": zlib.createBrotliCompress,
-    "zstd": zlib.createZstdCompress,
+  // node:zlib NodeMode values (DEFLATE, GZIP, DEFLATERAW, BROTLI_ENCODE,
+  // ZSTD_COMPRESS) — the native transformer initializes the matching engine
+  // with node:zlib's defaults, so output bytes match the node-backed
+  // implementation this replaced.
+  const modes = {
+    __proto__: null,
+    "deflate": 1,
+    "deflate-raw": 5,
+    "gzip": 3,
+    "brotli": 9,
+    "zstd": 10,
   };
 
-  if (!(format in builders))
-    throw $ERR_INVALID_ARG_VALUE("format", format, "must be one of: " + Object.keys(builders).join(", "));
+  if (!(format in modes))
+    throw $ERR_INVALID_ARG_VALUE("format", format, "must be one of: " + Object.keys(modes).join(", "));
+
+  const transform = $createCompressionTransform(modes[format]);
 
-  const transform = newBufferSourceTransformPairFromDuplex(builders[format]());
-  $putByIdDirectPrivate(this, "readable", transform.readable);
-  $putByIdDirectPrivate(this, "writable", transform.writable);
+  $putByIdDirectPrivate(this, "readable", $getByIdDirectPrivate(transform, "readable"));
+  $putByIdDirectPrivate(this, "writable", $getByIdDirectPrivate(transform, "writable"));
 
   return this;
 }

src/js/builtins/DecompressionStream.ts

@@ -1,21 +1,22 @@
 export function initializeDecompressionStream(this, format) {
-  const zlib = require("node:zlib");
-  const { newBufferSourceTransformPairFromDuplex } = require("internal/webstreams_adapters");
-
-  const builders = {
-    "deflate": zlib.createInflate,
-    "deflate-raw": zlib.createInflateRaw,
-    "gzip": zlib.createGunzip,
-    "brotli": zlib.createBrotliDecompress,
-    "zstd": zlib.createZstdDecompress,
+  // node:zlib NodeMode values (INFLATE, GUNZIP, INFLATERAW, BROTLI_DECODE,
+  // ZSTD_DECOMPRESS) — see CompressionStream for the encode-side table.
+  const modes = {
+    __proto__: null,
+    "deflate": 2,
+    "deflate-raw": 6,
+    "gzip": 4,
+    "brotli": 8,
+    "zstd": 11,
   };
 
-  if (!(format in builders))
-    throw $ERR_INVALID_ARG_VALUE("format", format, "must be one of: " + Object.keys(builders).join(", "));
+  if (!(format in modes))
+    throw $ERR_INVALID_ARG_VALUE("format", format, "must be one of: " + Object.keys(modes).join(", "));
+
+  const transform = $createCompressionTransform(modes[format]);
 
-  const transform = newBufferSourceTransformPairFromDuplex(builders[format]());
-  $putByIdDirectPrivate(this, "readable", transform.readable);
-  $putByIdDirectPrivate(this, "writable", transform.writable);
+  $putByIdDirectPrivate(this, "readable", $getByIdDirectPrivate(transform, "readable"));
+  $putByIdDirectPrivate(this, "writable", $getByIdDirectPrivate(transform, "writable"));
 
   return this;
 }

src/js/builtins/TransformStream.ts

@@ -54,6 +54,10 @@ export function initializeTransformStream(this) {
       transformerDict["flush"] = transformer["flush"];
       if (typeof transformerDict["flush"] !== "function") $throwTypeError("transformer.flush should be a function");
     }
+    if ("cancel" in transformer) {
+      transformerDict["cancel"] = transformer["cancel"];
+      if (typeof transformerDict["cancel"] !== "function") $throwTypeError("transformer.cancel should be a function");
+    }
 
     if ("readableType" in transformer) throw new RangeError("TransformStream transformer has a readableType");
     if ("writableType" in transformer) throw new RangeError("TransformStream transformer has a writableType");