script/dom/
defaultteereadrequest.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
4
5use std::cell::Cell;
6use std::rc::Rc;
7
8use dom_struct::dom_struct;
9use js::jsapi::{Heap, JSAutoRealm};
10use js::jsval::{JSVal, UndefinedValue};
11use js::rust::HandleValue as SafeHandleValue;
12
13use super::bindings::reflector::reflect_dom_object;
14use super::bindings::root::DomRoot;
15use super::bindings::structuredclone;
16use crate::dom::bindings::reflector::{DomGlobal, Reflector};
17use crate::dom::bindings::root::Dom;
18use crate::dom::bindings::trace::RootedTraceableBox;
19use crate::dom::defaultteeunderlyingsource::DefaultTeeUnderlyingSource;
20use crate::dom::globalscope::GlobalScope;
21use crate::dom::promise::Promise;
22use crate::dom::readablestream::ReadableStream;
23use crate::microtask::{Microtask, MicrotaskRunnable};
24use crate::realms::enter_realm;
25use crate::script_runtime::{CanGc, JSContext as SafeJSContext};
26
27#[derive(JSTraceable, MallocSizeOf)]
28#[cfg_attr(crown, allow(crown::unrooted_must_root))]
29pub(crate) struct DefaultTeeReadRequestMicrotask {
30    #[ignore_malloc_size_of = "mozjs"]
31    chunk: Box<Heap<JSVal>>,
32    tee_read_request: Dom<DefaultTeeReadRequest>,
33}
34
35impl MicrotaskRunnable for DefaultTeeReadRequestMicrotask {
36    fn handler(&self, can_gc: CanGc) {
37        let cx = GlobalScope::get_cx();
38        self.tee_read_request.chunk_steps(cx, &self.chunk, can_gc);
39    }
40
41    fn enter_realm(&self) -> JSAutoRealm {
42        enter_realm(&*self.tee_read_request)
43    }
44}
45
46#[dom_struct]
47/// <https://streams.spec.whatwg.org/#ref-for-read-request%E2%91%A2>
48pub(crate) struct DefaultTeeReadRequest {
49    reflector_: Reflector,
50    stream: Dom<ReadableStream>,
51    branch_1: Dom<ReadableStream>,
52    branch_2: Dom<ReadableStream>,
53    #[conditional_malloc_size_of]
54    reading: Rc<Cell<bool>>,
55    #[conditional_malloc_size_of]
56    read_again: Rc<Cell<bool>>,
57    #[conditional_malloc_size_of]
58    canceled_1: Rc<Cell<bool>>,
59    #[conditional_malloc_size_of]
60    canceled_2: Rc<Cell<bool>>,
61    #[conditional_malloc_size_of]
62    clone_for_branch_2: Rc<Cell<bool>>,
63    #[conditional_malloc_size_of]
64    cancel_promise: Rc<Promise>,
65    tee_underlying_source: Dom<DefaultTeeUnderlyingSource>,
66}
67impl DefaultTeeReadRequest {
68    #[expect(clippy::too_many_arguments)]
69    #[cfg_attr(crown, allow(crown::unrooted_must_root))]
70    pub(crate) fn new(
71        stream: &ReadableStream,
72        branch_1: &ReadableStream,
73        branch_2: &ReadableStream,
74        reading: Rc<Cell<bool>>,
75        read_again: Rc<Cell<bool>>,
76        canceled_1: Rc<Cell<bool>>,
77        canceled_2: Rc<Cell<bool>>,
78        clone_for_branch_2: Rc<Cell<bool>>,
79        cancel_promise: Rc<Promise>,
80        tee_underlying_source: &DefaultTeeUnderlyingSource,
81        can_gc: CanGc,
82    ) -> DomRoot<Self> {
83        reflect_dom_object(
84            Box::new(DefaultTeeReadRequest {
85                reflector_: Reflector::new(),
86                stream: Dom::from_ref(stream),
87                branch_1: Dom::from_ref(branch_1),
88                branch_2: Dom::from_ref(branch_2),
89                reading,
90                read_again,
91                canceled_1,
92                canceled_2,
93                clone_for_branch_2,
94                cancel_promise,
95                tee_underlying_source: Dom::from_ref(tee_underlying_source),
96            }),
97            &*stream.global(),
98            can_gc,
99        )
100    }
101    /// Call into cancel of the stream,
102    /// <https://streams.spec.whatwg.org/#readable-stream-cancel>
103    pub(crate) fn stream_cancel(
104        &self,
105        cx: SafeJSContext,
106        global: &GlobalScope,
107        reason: SafeHandleValue,
108        can_gc: CanGc,
109    ) {
110        self.stream.cancel(cx, global, reason, can_gc);
111    }
112    /// Enqueue a microtask to perform the chunk steps
113    /// <https://streams.spec.whatwg.org/#ref-for-read-request-chunk-steps%E2%91%A2>
114    pub(crate) fn enqueue_chunk_steps(&self, chunk: RootedTraceableBox<Heap<JSVal>>) {
115        // Queue a microtask to perform the following steps:
116        let tee_read_request_chunk = DefaultTeeReadRequestMicrotask {
117            chunk: Heap::boxed(*chunk.handle()),
118            tee_read_request: Dom::from_ref(self),
119        };
120        self.stream
121            .global()
122            .enqueue_microtask(Microtask::ReadableStreamTeeReadRequest(
123                tee_read_request_chunk,
124            ));
125    }
126    /// <https://streams.spec.whatwg.org/#ref-for-read-request-chunk-steps%E2%91%A2>
127    #[expect(clippy::borrowed_box)]
128    pub(crate) fn chunk_steps(&self, cx: SafeJSContext, chunk: &Box<Heap<JSVal>>, can_gc: CanGc) {
129        let global = &self.stream.global();
130        // Set readAgain to false.
131        self.read_again.set(false);
132        // Let chunk1 and chunk2 be chunk.
133        let chunk1 = chunk;
134        let chunk2 = chunk;
135
136        rooted!(in(*cx) let chunk1_value = chunk1.get());
137        rooted!(in(*cx) let chunk2_value = chunk2.get());
138        // If canceled_2 is false and cloneForBranch2 is true,
139        if !self.canceled_2.get() && self.clone_for_branch_2.get() {
140            // Let cloneResult be StructuredClone(chunk2).
141            rooted!(in(*cx) let mut clone_result = UndefinedValue());
142            let data = structuredclone::write(cx, chunk2_value.handle(), None).unwrap();
143            // If cloneResult is an abrupt completion,
144            if structuredclone::read(global, data, clone_result.handle_mut(), can_gc).is_err() {
145                // Perform ! ReadableStreamDefaultControllerError(branch_1.[[controller]], cloneResult.[[Value]]).
146                self.readable_stream_default_controller_error(
147                    &self.branch_1,
148                    clone_result.handle(),
149                    can_gc,
150                );
151
152                // Perform ! ReadableStreamDefaultControllerError(branch_2.[[controller]], cloneResult.[[Value]]).
153                self.readable_stream_default_controller_error(
154                    &self.branch_2,
155                    clone_result.handle(),
156                    can_gc,
157                );
158                // Resolve cancelPromise with ! ReadableStreamCancel(stream, cloneResult.[[Value]]).
159                self.stream_cancel(cx, global, clone_result.handle(), can_gc);
160                // Return.
161                return;
162            } else {
163                // Otherwise, set chunk2 to cloneResult.[[Value]].
164                chunk2.set(*clone_result);
165            }
166        }
167        // If canceled_1 is false, perform ! ReadableStreamDefaultControllerEnqueue(branch_1.[[controller]], chunk1).
168        if !self.canceled_1.get() {
169            self.readable_stream_default_controller_enqueue(
170                &self.branch_1,
171                chunk1_value.handle(),
172                can_gc,
173            );
174        }
175        // If canceled_2 is false, perform ! ReadableStreamDefaultControllerEnqueue(branch_2.[[controller]], chunk2).
176        if !self.canceled_2.get() {
177            self.readable_stream_default_controller_enqueue(
178                &self.branch_2,
179                chunk2_value.handle(),
180                can_gc,
181            );
182        }
183        // Set reading to false.
184        self.reading.set(false);
185        // If readAgain is true, perform pullAlgorithm.
186        if self.read_again.get() {
187            self.pull_algorithm(can_gc);
188        }
189    }
190    /// <https://streams.spec.whatwg.org/#read-request-close-steps>
191    pub(crate) fn close_steps(&self, can_gc: CanGc) {
192        // Set reading to false.
193        self.reading.set(false);
194        // If canceled_1 is false, perform ! ReadableStreamDefaultControllerClose(branch_1.[[controller]]).
195        if !self.canceled_1.get() {
196            self.readable_stream_default_controller_close(&self.branch_1, can_gc);
197        }
198        // If canceled_2 is false, perform ! ReadableStreamDefaultControllerClose(branch_2.[[controller]]).
199        if !self.canceled_2.get() {
200            self.readable_stream_default_controller_close(&self.branch_2, can_gc);
201        }
202        // If canceled_1 is false or canceled_2 is false, resolve cancelPromise with undefined.
203        if !self.canceled_1.get() || !self.canceled_2.get() {
204            self.cancel_promise.resolve_native(&(), can_gc);
205        }
206    }
207    /// <https://streams.spec.whatwg.org/#read-request-error-steps>
208    pub(crate) fn error_steps(&self) {
209        // Set reading to false.
210        self.reading.set(false);
211    }
212    /// Call into enqueue of the default controller of a stream,
213    /// <https://streams.spec.whatwg.org/#readable-stream-default-controller-enqueue>
214    fn readable_stream_default_controller_enqueue(
215        &self,
216        stream: &ReadableStream,
217        chunk: SafeHandleValue,
218        can_gc: CanGc,
219    ) {
220        stream
221            .get_default_controller()
222            .enqueue(GlobalScope::get_cx(), chunk, can_gc)
223            .expect("enqueue failed for stream controller in DefaultTeeReadRequest");
224    }
225
226    /// Call into close of the default controller of a stream,
227    /// <https://streams.spec.whatwg.org/#readable-stream-default-controller-close>
228    fn readable_stream_default_controller_close(&self, stream: &ReadableStream, can_gc: CanGc) {
229        stream.get_default_controller().close(can_gc);
230    }
231
232    /// Call into error of the default controller of stream,
233    /// <https://streams.spec.whatwg.org/#readable-stream-default-controller-error>
234    fn readable_stream_default_controller_error(
235        &self,
236        stream: &ReadableStream,
237        error: SafeHandleValue,
238        can_gc: CanGc,
239    ) {
240        stream.get_default_controller().error(error, can_gc);
241    }
242
243    pub(crate) fn pull_algorithm(&self, can_gc: CanGc) {
244        self.tee_underlying_source.pull_algorithm(can_gc);
245    }
246}
script/dom/defaultteereadrequest.rs

script/dom/
defaultteereadrequest.rs
