script_bindings/
record.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 https://mozilla.org/MPL/2.0/. */
4
5//! The `Record` (open-ended dictionary) type.
6
7use std::cmp::Eq;
8use std::hash::Hash;
9use std::marker::Sized;
10use std::ops::{Deref, DerefMut};
11
12use indexmap::IndexMap;
13use js::context::{JSContext, RawJSContext};
14use js::conversions::{ConversionResult, FromJSValConvertible, ToJSValConvertible};
15use js::jsapi::{
16    JS_NewPlainObject, JSITER_HIDDEN, JSITER_OWNONLY, JSITER_SYMBOLS, JSPROP_ENUMERATE,
17    PropertyDescriptor,
18};
19use js::jsval::{ObjectValue, UndefinedValue};
20use js::rust::wrappers::JS_DefineUCProperty2;
21use js::rust::wrappers2::{
22    GetPropertyKeys, JS_GetOwnPropertyDescriptorById, JS_GetPropertyById, JS_IdToValue,
23};
24use js::rust::{HandleId, HandleValue, IdVector, MutableHandleValue};
25
26use crate::conversions::jsid_to_string;
27use crate::str::{ByteString, DOMString, USVString};
28
29pub trait RecordKey: Eq + Hash + Sized {
30    fn to_utf16_vec(&self) -> Vec<u16>;
31
32    /// Attempt to extract a key from a JS id.
33    #[allow(clippy::result_unit_err)]
34    fn from_id(cx: &mut JSContext, id: HandleId) -> Result<ConversionResult<Self>, ()>;
35}
36
37impl RecordKey for DOMString {
38    fn to_utf16_vec(&self) -> Vec<u16> {
39        self.str().encode_utf16().collect::<Vec<_>>()
40    }
41
42    fn from_id(cx: &mut JSContext, id: HandleId) -> Result<ConversionResult<Self>, ()> {
43        match jsid_to_string(cx, id) {
44            Some(s) => Ok(ConversionResult::Success(s)),
45            None => Ok(ConversionResult::Failure(c"Failed to get DOMString".into())),
46        }
47    }
48}
49
50impl RecordKey for USVString {
51    fn to_utf16_vec(&self) -> Vec<u16> {
52        self.0.encode_utf16().collect::<Vec<_>>()
53    }
54
55    fn from_id(cx: &mut JSContext, id: HandleId) -> Result<ConversionResult<Self>, ()> {
56        rooted!(&in(cx) let mut jsid_value = UndefinedValue());
57        unsafe { JS_IdToValue(cx, *id.as_ref(cx), jsid_value.handle_mut()) };
58
59        USVString::safe_from_jsval(cx, jsid_value.handle(), ())
60    }
61}
62
63impl RecordKey for ByteString {
64    fn to_utf16_vec(&self) -> Vec<u16> {
65        self.iter().map(|&x| x as u16).collect::<Vec<u16>>()
66    }
67
68    fn from_id(cx: &mut JSContext, id: HandleId) -> Result<ConversionResult<Self>, ()> {
69        rooted!(&in(cx) let mut jsid_value = UndefinedValue());
70        unsafe { JS_IdToValue(cx, *id.as_ref(cx), jsid_value.handle_mut()) };
71
72        ByteString::safe_from_jsval(cx, jsid_value.handle(), ())
73    }
74}
75
76/// The `Record` (open-ended dictionary) type.
77#[derive(Clone, JSTraceable)]
78pub struct Record<K: RecordKey, V> {
79    #[custom_trace]
80    map: IndexMap<K, V>,
81}
82
83impl<K: RecordKey, V> Record<K, V> {
84    /// Create an empty `Record`.
85    pub fn new() -> Self {
86        Record {
87            map: IndexMap::new(),
88        }
89    }
90}
91
92impl<K: RecordKey, V> Deref for Record<K, V> {
93    type Target = IndexMap<K, V>;
94
95    fn deref(&self) -> &Self::Target {
96        &self.map
97    }
98}
99
100impl<K: RecordKey, V> DerefMut for Record<K, V> {
101    fn deref_mut(&mut self) -> &mut Self::Target {
102        &mut self.map
103    }
104}
105
106impl<K, V, C> FromJSValConvertible for Record<K, V>
107where
108    K: RecordKey,
109    V: FromJSValConvertible<Config = C>,
110    C: Clone,
111{
112    type Config = C;
113    unsafe fn from_jsval(
114        _cx: *mut RawJSContext,
115        value: HandleValue,
116        config: C,
117    ) -> Result<ConversionResult<Self>, ()> {
118        // TODO https://github.com/servo/mozjs/issues/749
119        let mut cx = unsafe { crate::script_runtime::temp_cx() };
120        FromJSValConvertible::safe_from_jsval(&mut cx, value, config)
121    }
122
123    fn safe_from_jsval(
124        cx: &mut JSContext,
125        value: HandleValue,
126        config: C,
127    ) -> Result<ConversionResult<Self>, ()> {
128        if !value.is_object() {
129            return Ok(ConversionResult::Failure(
130                c"Record value was not an object".into(),
131            ));
132        }
133
134        rooted!(&in(cx) let object = value.to_object());
135        let mut ids = unsafe { IdVector::new(cx.raw_cx()) };
136        if unsafe {
137            !GetPropertyKeys(
138                cx,
139                object.handle(),
140                JSITER_OWNONLY | JSITER_HIDDEN | JSITER_SYMBOLS,
141                ids.handle_mut(),
142            )
143        } {
144            return Err(());
145        }
146
147        let mut map = IndexMap::new();
148        for id in &*ids {
149            rooted!(&in(cx) let id = *id);
150            rooted!(&in(cx) let mut desc = PropertyDescriptor::default());
151
152            let mut is_none = false;
153            if unsafe {
154                !JS_GetOwnPropertyDescriptorById(
155                    cx,
156                    object.handle(),
157                    id.handle(),
158                    desc.handle_mut(),
159                    &mut is_none,
160                )
161            } {
162                return Err(());
163            }
164
165            if !desc.enumerable_() {
166                continue;
167            }
168
169            let key = match K::from_id(cx, id.handle())? {
170                ConversionResult::Success(key) => key,
171                ConversionResult::Failure(message) => {
172                    return Ok(ConversionResult::Failure(message));
173                },
174            };
175
176            rooted!(&in(cx) let mut property = UndefinedValue());
177            if unsafe {
178                !JS_GetPropertyById(cx, object.handle(), id.handle(), property.handle_mut())
179            } {
180                return Err(());
181            }
182
183            let property = match V::safe_from_jsval(cx, property.handle(), config.clone())? {
184                ConversionResult::Success(property) => property,
185                ConversionResult::Failure(message) => {
186                    return Ok(ConversionResult::Failure(message));
187                },
188            };
189            map.insert(key, property);
190        }
191
192        Ok(ConversionResult::Success(Record { map }))
193    }
194}
195
196impl<K, V> ToJSValConvertible for Record<K, V>
197where
198    K: RecordKey,
199    V: ToJSValConvertible,
200{
201    #[inline]
202    unsafe fn to_jsval(&self, cx: *mut RawJSContext, mut rval: MutableHandleValue) {
203        rooted!(in(cx) let js_object = JS_NewPlainObject(cx));
204        assert!(!js_object.handle().is_null());
205
206        rooted!(in(cx) let mut js_value = UndefinedValue());
207        for (key, value) in &self.map {
208            let key = key.to_utf16_vec();
209            value.to_jsval(cx, js_value.handle_mut());
210
211            assert!(JS_DefineUCProperty2(
212                cx,
213                js_object.handle(),
214                key.as_ptr(),
215                key.len(),
216                js_value.handle(),
217                JSPROP_ENUMERATE as u32
218            ));
219        }
220
221        rval.set(ObjectValue(js_object.handle().get()));
222    }
223}
224
225impl<K: RecordKey, V> Default for Record<K, V> {
226    fn default() -> Self {
227        Self::new()
228    }
229}
script_bindings/record.rs

script_bindings/
record.rs
