1 files changed, 80 insertions, 3 deletions

diff --git a/ext/web/06_streams.js b/ext/web/06_streams.js
index 01f84aa2c..0849d221d 100644
--- a/ext/web/06_streams.js
+++ b/ext/web/06_streams.js
@@ -1,4 +1,5 @@
 // Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// deno-lint-ignore-file camelcase
 
 // @ts-check
 /// <reference path="../webidl/internal.d.ts" />
@@ -7,7 +8,17 @@
 /// <reference lib="esnext" />
 
 const core = globalThis.Deno.core;
-const ops = core.ops;
+const internals = globalThis.__bootstrap.internals;
+const {
+  op_arraybuffer_was_detached,
+  op_transfer_arraybuffer,
+  op_readable_stream_resource_allocate,
+  op_readable_stream_resource_get_sink,
+  op_readable_stream_resource_write_error,
+  op_readable_stream_resource_write_buf,
+  op_readable_stream_resource_close,
+  op_readable_stream_resource_await_close,
+} = core.ensureFastOps();
 import * as webidl from "ext:deno_webidl/00_webidl.js";
 import { structuredClone } from "ext:deno_web/02_structured_clone.js";
 import {
@@ -61,6 +72,7 @@ const {
   SafeWeakMap,
   // TODO(lucacasonato): add SharedArrayBuffer to primordials
   // SharedArrayBufferPrototype,
+  String,
   Symbol,
   SymbolAsyncIterator,
   SymbolIterator,
@@ -218,7 +230,7 @@ function isDetachedBuffer(O) {
     return false;
   }
   return ArrayBufferPrototypeGetByteLength(O) === 0 &&
-    ops.op_arraybuffer_was_detached(O);
+    op_arraybuffer_was_detached(O);
 }
 
 /**
@@ -244,7 +256,7 @@ function canTransferArrayBuffer(O) {
  * @returns {ArrayBufferLike}
  */
 function transferArrayBuffer(O) {
-  return ops.op_transfer_arraybuffer(O);
+  return op_transfer_arraybuffer(O);
 }
 
 /**
@@ -695,6 +707,68 @@ function isReadableStreamDisturbed(stream) {
   return stream[_disturbed];
 }
 
+/**
+ * Create a new resource that wraps a ReadableStream. The resource will support
+ * read operations, and those read operations will be fed by the output of the
+ * ReadableStream source.
+ * @param {ReadableStream<Uint8Array>} stream
+ * @returns {number}
+ */
+function resourceForReadableStream(stream) {
+  const reader = acquireReadableStreamDefaultReader(stream);
+
+  // Allocate the resource
+  const rid = op_readable_stream_resource_allocate();
+
+  // Close the Reader we get from the ReadableStream when the resource is closed, ignoring any errors
+  PromisePrototypeCatch(
+    PromisePrototypeThen(
+      op_readable_stream_resource_await_close(rid),
+      () => reader.cancel(),
+    ),
+    () => {},
+  );
+
+  // The ops here look like op_write_all/op_close, but we're not actually writing to a
+  // real resource.
+  (async () => {
+    try {
+      // This allocation is freed in the finally block below, guaranteeing it won't leak
+      const sink = op_readable_stream_resource_get_sink(rid);
+      try {
+        while (true) {
+          let value;
+          try {
+            const read = await reader.read();
+            value = read.value;
+            if (read.done) {
+              break;
+            }
+          } catch (err) {
+            const message = err.message;
+            if (message) {
+              await op_readable_stream_resource_write_error(sink, err.message);
+            } else {
+              await op_readable_stream_resource_write_error(sink, String(err));
+            }
+            break;
+          }
+          // If the chunk has non-zero length, write it
+          if (value.length > 0) {
+            await op_readable_stream_resource_write_buf(sink, value);
+          }
+        }
+      } finally {
+        op_readable_stream_resource_close(sink);
+      }
+    } catch (err) {
+      // Something went terribly wrong with this stream -- log and continue
+      console.error("Unexpected internal error on stream", err);
+    }
+  })();
+  return rid;
+}
+
 const DEFAULT_CHUNK_SIZE = 64 * 1024; // 64 KiB
 
 // A finalization registry to clean up underlying resources that are GC'ed.
@@ -6454,6 +6528,8 @@ webidl.converters.StreamPipeOptions = webidl
     { key: "signal", converter: webidl.converters.AbortSignal },
   ]);
 
+internals.resourceForReadableStream = resourceForReadableStream;
+
 export {
   // Non-Public
   _state,
@@ -6482,6 +6558,7 @@ export {
   ReadableStreamPrototype,
   readableStreamTee,
   readableStreamThrowIfErrored,
+  resourceForReadableStream,
   TransformStream,
   TransformStreamDefaultController,
   WritableStream,