script/dom/
countqueuingstrategy.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::rc::Rc;
6
7use dom_struct::dom_struct;
8use js::jsapi::{CallArgs, JSContext};
9use js::jsval::{Int32Value, JSVal};
10use js::rust::HandleObject;
11
12use super::bindings::codegen::Bindings::FunctionBinding::Function;
13use super::bindings::codegen::Bindings::QueuingStrategyBinding::{
14    CountQueuingStrategyMethods, QueuingStrategy, QueuingStrategyInit, QueuingStrategySize,
15};
16use super::bindings::error::{Error, Fallible};
17use super::bindings::reflector::{DomGlobal, Reflector, reflect_dom_object_with_proto};
18use super::bindings::root::DomRoot;
19use super::types::GlobalScope;
20use crate::script_runtime::CanGc;
21use crate::{native_fn, native_raw_obj_fn};
22
23#[dom_struct]
24pub(crate) struct CountQueuingStrategy {
25    reflector_: Reflector,
26    high_water_mark: f64,
27}
28
29impl CountQueuingStrategy {
30    pub(crate) fn new_inherited(init: f64) -> Self {
31        Self {
32            reflector_: Reflector::new(),
33            high_water_mark: init,
34        }
35    }
36
37    pub(crate) fn new(
38        global: &GlobalScope,
39        proto: Option<HandleObject>,
40        init: f64,
41        can_gc: CanGc,
42    ) -> DomRoot<Self> {
43        reflect_dom_object_with_proto(Box::new(Self::new_inherited(init)), global, proto, can_gc)
44    }
45}
46
47impl CountQueuingStrategyMethods<crate::DomTypeHolder> for CountQueuingStrategy {
48    /// <https://streams.spec.whatwg.org/#cqs-constructor>
49    fn Constructor(
50        global: &GlobalScope,
51        proto: Option<HandleObject>,
52        can_gc: CanGc,
53        init: &QueuingStrategyInit,
54    ) -> DomRoot<Self> {
55        Self::new(global, proto, init.highWaterMark, can_gc)
56    }
57
58    /// <https://streams.spec.whatwg.org/#cqs-high-water-mark>
59    fn HighWaterMark(&self) -> f64 {
60        self.high_water_mark
61    }
62
63    /// <https://streams.spec.whatwg.org/#cqs-size>
64    fn GetSize(&self, _can_gc: CanGc) -> Fallible<Rc<Function>> {
65        let global = self.global();
66        // Return this's relevant global object's count queuing strategy
67        // size function.
68        if let Some(fun) = global.get_count_queuing_strategy_size() {
69            return Ok(fun);
70        }
71
72        // Step 1. Let steps be the following steps, given chunk
73        // Note: See ByteLengthQueuingStrategySize instead.
74
75        // Step 2. Let F be !CreateBuiltinFunction(steps, 1, "size", « »,
76        // globalObject’s relevant Realm).
77        let fun = native_fn!(count_queuing_strategy_size, c"size", 0, 0);
78        // Step 3. Set globalObject’s count queuing strategy size function to
79        // a Function that represents a reference to F,
80        // with callback context equal to globalObject’s relevant settings object.
81        global.set_count_queuing_strategy_size(fun.clone());
82        Ok(fun)
83    }
84}
85
86/// <https://streams.spec.whatwg.org/#count-queuing-strategy-size-function>
87#[allow(unsafe_code)]
88pub(crate) unsafe fn count_queuing_strategy_size(
89    _cx: *mut JSContext,
90    argc: u32,
91    vp: *mut JSVal,
92) -> bool {
93    let args = CallArgs::from_vp(vp, argc);
94    // Step 1.1. Return 1.
95    args.rval().set(Int32Value(1));
96    true
97}
98
99/// Extract the high water mark from a QueuingStrategy.
100/// If the high water mark is not set, return the default value.
101///
102/// <https://streams.spec.whatwg.org/#validate-and-normalize-high-water-mark>
103pub(crate) fn extract_high_water_mark(
104    strategy: &QueuingStrategy,
105    default_hwm: f64,
106) -> Result<f64, Error> {
107    if strategy.highWaterMark.is_none() {
108        return Ok(default_hwm);
109    }
110
111    let high_water_mark = strategy.highWaterMark.unwrap();
112    if high_water_mark.is_nan() || high_water_mark < 0.0 {
113        return Err(Error::Range(
114            "High water mark must be a non-negative number.".to_string(),
115        ));
116    }
117
118    Ok(high_water_mark)
119}
120
121/// Extract the size algorithm from a QueuingStrategy.
122/// If the size algorithm is not set, return a fallback function which always returns 1.
123///
124/// <https://streams.spec.whatwg.org/#make-size-algorithm-from-size-function>
125pub(crate) fn extract_size_algorithm(
126    strategy: &QueuingStrategy,
127    _can_gc: CanGc,
128) -> Rc<QueuingStrategySize> {
129    if strategy.size.is_none() {
130        let cx = GlobalScope::get_cx();
131        let fun_obj = native_raw_obj_fn!(cx, count_queuing_strategy_size, c"size", 0, 0);
132        #[allow(unsafe_code)]
133        unsafe {
134            return QueuingStrategySize::new(cx, fun_obj);
135        };
136    }
137    strategy.size.as_ref().unwrap().clone()
138}
script/dom/countqueuingstrategy.rs

script/dom/
countqueuingstrategy.rs
