servo_config/
prefs.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//! Preferences are the global configuration options that can be changed at runtime.
6
7use std::env::consts::ARCH;
8use std::sync::{RwLock, RwLockReadGuard};
9use std::time::Duration;
10
11use serde::{Deserialize, Serialize};
12use servo_config_macro::ServoPreferences;
13
14pub use crate::pref_util::PrefValue;
15
16static PREFERENCES: RwLock<Preferences> = RwLock::new(Preferences::const_default());
17
18/// A trait to be implemented by components that wish to be notified about runtime changes to the
19/// global preferences for the current process.
20pub trait PreferencesObserver: Send + Sync {
21    /// This method is called when the global preferences have been updated. The argument to the
22    /// method is an array of tuples where the first component is the name of the preference and
23    /// the second component is the new value of the preference.
24    fn prefs_changed(&self, _changes: &[(&'static str, PrefValue)]) {}
25}
26
27static OBSERVERS: RwLock<Vec<Box<dyn PreferencesObserver>>> = RwLock::new(Vec::new());
28
29#[inline]
30/// Get the current set of global preferences for Servo.
31pub fn get() -> RwLockReadGuard<'static, Preferences> {
32    PREFERENCES.read().unwrap()
33}
34
35/// Subscribe to notifications about changes to the global preferences for the current process.
36pub fn add_observer(observer: Box<dyn PreferencesObserver>) {
37    OBSERVERS.write().unwrap().push(observer);
38}
39
40/// Update the values of the global preferences for the current process. This also notifies the
41/// observers previously added using [`add_observer`].
42pub fn set(preferences: Preferences) {
43    // Get list of changes, returning early if the preferences haven't changed.
44    let changed = preferences.diff(&PREFERENCES.read().unwrap());
45    if changed.is_empty() {
46        return;
47    }
48
49    // Map between Stylo preference names and Servo preference names as the This should be
50    // kept in sync with components/script_bindings/codegen/run.py which generates the
51    // DOM CSS style accessors.
52    stylo_static_prefs::set_pref!("layout.unimplemented", preferences.layout_unimplemented);
53    stylo_static_prefs::set_pref!("layout.threads", preferences.layout_threads as i32);
54    stylo_static_prefs::set_pref!("layout.columns.enabled", preferences.layout_columns_enabled);
55    stylo_static_prefs::set_pref!("layout.grid.enabled", preferences.layout_grid_enabled);
56    stylo_static_prefs::set_pref!(
57        "layout.css.alpha-color-function.enabled",
58        preferences.layout_css_alpha_color_function_enabled
59    );
60    stylo_static_prefs::set_pref!(
61        "layout.css.ellipse-corners.enabled",
62        preferences.layout_css_ellipse_corners_enabled
63    );
64    stylo_static_prefs::set_pref!(
65        "layout.css.progress-function.enabled",
66        preferences.layout_css_progress_function_enabled
67    );
68    stylo_static_prefs::set_pref!(
69        "layout.writing-mode.enabled",
70        preferences.layout_writing_mode_enabled
71    );
72    stylo_static_prefs::set_pref!(
73        "layout.container-queries.enabled",
74        preferences.layout_container_queries_enabled
75    );
76    stylo_static_prefs::set_pref!(
77        "layout.variable_fonts.enabled",
78        preferences.layout_variable_fonts_enabled
79    );
80    stylo_static_prefs::set_pref!("layout.flexbox.balance", preferences.layout_flexbox_balance);
81
82    *PREFERENCES.write().unwrap() = preferences;
83
84    for observer in &*OBSERVERS.read().unwrap() {
85        observer.prefs_changed(&changed);
86    }
87}
88
89/// A convenience macro for accessing a preference value using its static path.
90/// Passing an invalid path is a compile-time error.
91#[macro_export]
92macro_rules! pref {
93    ($name: ident) => {
94        $crate::prefs::get().$name.clone()
95    };
96}
97
98/// The set of global preferences supported by Servo.
99///
100/// Each preference has a default value that determines its initial state. These defaults
101/// fall into roughly three categories:
102/// - **Stable**: enabled by default.
103/// - **Experimental**: disabled by default, but intended to be enabled for experimental use.
104/// - **Unstable**: disabled by default.
105///
106/// For a full overview of which preferences are experimental, see the
107/// [experimental features documentation](https://book.servo.org/design-documentation/experimental-features.html).
108#[derive(Clone, Deserialize, Serialize, ServoPreferences)]
109pub struct Preferences {
110    pub fonts_default: String,
111    pub fonts_serif: String,
112    pub fonts_sans_serif: String,
113    pub fonts_monospace: String,
114    pub fonts_default_size: i64,
115    pub fonts_default_monospace_size: i64,
116    /// The amount of time that a half cycle of a text caret blink takes in milliseconds.
117    /// If this value is less than or equal to zero, then caret blink is disabled.
118    pub editing_caret_blink_time: i64,
119    pub css_animations_testing_enabled: bool,
120    /// Start the devtools server at startup
121    pub devtools_server_enabled: bool,
122    /// The address:port the devtools server listens to, default to 127.0.0.1:7000.
123    pub devtools_server_listen_address: String,
124    // feature: WebGPU | #24706 | Web/API/WebGPU_API
125    pub dom_webgpu_enabled: bool,
126    /// List of comma-separated backends to be used by wgpu.
127    pub dom_webgpu_wgpu_backend: String,
128    // feature: Adopted Stylesheet | #38132 | Web/API/Document/adoptedStyleSheets
129    pub dom_adoptedstylesheet_enabled: bool,
130    pub dom_allow_preloading_module_descendants: bool,
131    // feature: Clipboard API | #36084 | Web/API/Clipboard_API
132    pub dom_async_clipboard_enabled: bool,
133    pub dom_bluetooth_enabled: bool,
134    pub dom_bluetooth_testing_enabled: bool,
135    pub dom_allow_scripts_to_close_windows: bool,
136    // feature: Media Capture and Streams API | #26861 | Web/API/Media_Capture_and_Streams_API
137    pub dom_canvas_capture_enabled: bool,
138    pub dom_canvas_text_enabled: bool,
139    /// Selects canvas backend
140    ///
141    /// Available values:
142    /// - vello
143    /// - Everything else selects vello_cpu
144    pub dom_canvas_backend: String,
145    /// Maximum number of buffered canvas commands before an automatic flush is triggered.
146    ///
147    /// A lower value keeps the paint thread fed with work (better parallelism),
148    /// while a higher value improves batching efficiency (fewer channel operations, lower power).
149    ///
150    /// See <https://github.com/servo/servo/pull/45301> for measurements.
151    pub dom_canvas_msg_buffer_size: u64,
152    pub dom_composition_event_enabled: bool,
153    // feature: CookieStore | #37674 | Web/API/CookieStore
154    pub dom_cookiestore_enabled: bool,
155    // feature: Credential Management API | #38788 | Web/API/Credential_Management_API
156    pub dom_credential_management_enabled: bool,
157    // feature: WebCrypto API | #40687 | Web/API/Web_Crypto_API
158    pub dom_crypto_subtle_enabled: bool,
159    pub dom_document_dblclick_timeout: i64,
160    pub dom_document_dblclick_dist: i64,
161    // feature: File and Directory Entries API | #45653 | Web/API/File_and_Directory_Entries_API
162    pub dom_entries_api_enabled: bool,
163    // feature: Document.execCommand | #25005 | Web/API/Document/execCommand
164    pub dom_exec_command_enabled: bool,
165    // feature: CSS Font Loading API | #29376 | Web/API/CSS_Font_Loading_API
166    pub dom_fontface_enabled: bool,
167    pub dom_fullscreen_test: bool,
168    // feature: Gamepad API | #10977 | Web/API/Gamepad_API
169    pub dom_gamepad_enabled: bool,
170    // feature: Geolocation API | #38903 | Web/API/Geolocation_API
171    pub dom_geolocation_enabled: bool,
172    // feature: Screen Wake Lock API | #43615 | Web/API/Screen_Wake_Lock_API
173    pub dom_wakelock_enabled: bool,
174    // feature: IndexedDB | #6963 | Web/API/IndexedDB_API
175    pub dom_indexeddb_enabled: bool,
176    // feature: IntersectionObserver | #35767 | Web/API/Intersection_Observer_API
177    pub dom_intersection_observer_enabled: bool,
178    pub dom_microdata_testing_enabled: bool,
179    // feature: Navigator.registerProtocolHandler() | #40615 | Web/API/Navigator/registerProtocolHandler
180    pub dom_navigator_protocol_handlers_enabled: bool,
181    // feature: Notification API | #34841 | Web/API/Notifications_API
182    pub dom_notification_enabled: bool,
183    // feature: OffscreenCanvas | #34111 | Web/API/OffscreenCanvas
184    pub dom_offscreen_canvas_enabled: bool,
185    pub dom_parallel_css_parsing_enabled: bool,
186    // feature: Permissions API | #31235 | Web/API/Permissions_API
187    pub dom_permissions_enabled: bool,
188    pub dom_permissions_testing_allowed_in_nonsecure_contexts: bool,
189    // feature: ResizeObserver | #39790 | Web/API/ResizeObserver
190    pub dom_resize_observer_enabled: bool,
191    // feature: Sanitizer API | #43948 | Web/API/HTML_Sanitizer_API
192    pub dom_sanitizer_enabled: bool,
193    pub dom_script_asynch: bool,
194    // feature: Storage API | #43976 | Web/API/Storage_API
195    pub dom_storage_manager_api_enabled: bool,
196    // feature: ServiceWorker | #36538 | Web/API/Service_Worker_API
197    pub dom_serviceworker_enabled: bool,
198    pub dom_serviceworker_timeout_seconds: i64,
199    // feature: SharedWorker | #7458 | Web/API/SharedWorker
200    pub dom_sharedworker_enabled: bool,
201    pub dom_servo_helpers_enabled: bool,
202    pub dom_servoparser_async_html_tokenizer_enabled: bool,
203    pub dom_testbinding_enabled: bool,
204    pub dom_testbinding_prefcontrolled_enabled: bool,
205    pub dom_testbinding_prefcontrolled2_enabled: bool,
206    pub dom_testbinding_preference_value_falsy: bool,
207    pub dom_testbinding_preference_value_quote_string_test: String,
208    pub dom_testbinding_preference_value_space_string_test: String,
209    pub dom_testbinding_preference_value_string_empty: String,
210    pub dom_testbinding_preference_value_string_test: String,
211    pub dom_testbinding_preference_value_truthy: bool,
212    pub dom_testing_element_activation_enabled: bool,
213    pub dom_testing_html_input_element_select_files_enabled: bool,
214    pub dom_testperf_enabled: bool,
215    // https://testutils.spec.whatwg.org#availability
216    pub dom_testutils_enabled: bool,
217    /// <https://w3c.github.io/touch-events/#conditionally-exposing-legacy-touch-event-apis>
218    pub dom_touch_events_legacy_apis_enabled: bool,
219    /// <https://html.spec.whatwg.org/multipage/#transient-activation-duration>
220    pub dom_transient_activation_duration_ms: i64,
221    // feature: Web Animations | #36950 | Web/API/Web_Animations_API
222    pub dom_web_animations_enabled: bool,
223    /// Enable WebGL2 APIs.
224    // feature: WebGL2 | #41394 | Web/API/WebGL2RenderingContext
225    pub dom_webgl2_enabled: bool,
226    // feature: WebRTC | #41396 | Web/API/WebRTC_API
227    pub dom_webrtc_enabled: bool,
228    // feature: WebRTC Transceiver | #41396 | Web/API/RTCRtpTransceiver
229    pub dom_webrtc_transceiver_enabled: bool,
230    pub dom_webxr_enabled: bool,
231    pub dom_webxr_test: bool,
232    pub dom_webxr_first_person_observer_view: bool,
233    pub dom_webxr_glwindow_enabled: bool,
234    pub dom_webxr_glwindow_left_right: bool,
235    pub dom_webxr_glwindow_red_cyan: bool,
236    pub dom_webxr_glwindow_spherical: bool,
237    pub dom_webxr_glwindow_cubemap: bool,
238    pub dom_webxr_hands_enabled: bool,
239    // feature: WebXR Layers | #27468 | Web/API/XRCompositionLayer
240    pub dom_webxr_layers_enabled: bool,
241    pub dom_webxr_openxr_enabled: bool,
242    pub dom_webxr_sessionavailable: bool,
243    pub dom_webxr_unsafe_assume_user_intent: bool,
244    pub dom_worklet_enabled: bool,
245    pub dom_worklet_blockingsleep_enabled: bool,
246    pub dom_worklet_testing_enabled: bool,
247    pub dom_worklet_timeout_ms: i64,
248    /// <https://drafts.csswg.org/cssom-view/#the-visualviewport-interface>
249    // feature: VisualViewport | #41341 | Web/API/VisualViewport
250    pub dom_visual_viewport_enabled: bool,
251    /// True to compile all WebRender shaders when Servo initializes. This is mostly
252    /// useful when modifying the shaders, to ensure they all compile after each change is
253    /// made.
254    pub gfx_precache_shaders: bool,
255    /// Whether or not antialiasing is enabled for text rendering.
256    pub gfx_text_antialiasing_enabled: bool,
257    /// Whether or not subpixel antialiasing is enabled for text rendering.
258    pub gfx_subpixel_text_antialiasing_enabled: bool,
259    pub gfx_texture_swizzling_enabled: bool,
260    /// The amount of image keys we request per batch for the image cache.
261    pub image_key_batch_size: i64,
262    /// Whether or not the DOM inspector should show shadow roots of user-agent shadow trees
263    pub inspector_show_servo_internal_shadow_roots: bool,
264    /// A locale tag (eg. es-ES) to use for language negotiation instead of the system locale.
265    /// An empty string represents no override.
266    /// TODO: Option<> support in PrefValue
267    pub intl_locale_override: String,
268    pub js_asmjs_enabled: bool,
269    pub js_baseline_interpreter_enabled: bool,
270    /// Whether to disable the jit within SpiderMonkey
271    pub js_disable_jit: bool,
272    pub js_baseline_jit_enabled: bool,
273    pub js_baseline_jit_unsafe_eager_compilation_enabled: bool,
274    pub js_ion_enabled: bool,
275    pub js_ion_unsafe_eager_compilation_enabled: bool,
276    pub js_mem_gc_compacting_enabled: bool,
277    pub js_mem_gc_empty_chunk_count_min: i64,
278    pub js_mem_gc_high_frequency_heap_growth_max: i64,
279    pub js_mem_gc_high_frequency_heap_growth_min: i64,
280    pub js_mem_gc_high_frequency_high_limit_mb: i64,
281    pub js_mem_gc_high_frequency_low_limit_mb: i64,
282    pub js_mem_gc_high_frequency_time_limit_ms: i64,
283    /// Whether or not incremental garbage collection is turned on. This is currently
284    /// turned off by default as pre-barriers are not implemented yet. If turned on, it
285    /// will likely lead to memory corruption.
286    ///
287    /// See <https://github.com/servo/servo/issues/7621>.
288    pub js_mem_gc_incremental_enabled: bool,
289    pub js_mem_gc_incremental_slice_ms: i64,
290    pub js_mem_gc_low_frequency_heap_growth: i64,
291    pub js_mem_gc_malloc_threshold_base_mb: i64,
292    pub js_mem_gc_per_zone_enabled: bool,
293    pub js_mem_gc_urgent_threshold_mb: i64,
294    pub js_mem_gc_zeal_frequency: i64,
295    pub js_mem_gc_zeal_level: i64,
296    pub js_mem_max: i64,
297    pub js_native_regex_enabled: bool,
298    pub js_offthread_compilation_enabled: bool,
299    pub js_timers_minimum_duration: i64,
300    pub js_wasm_baseline_enabled: bool,
301    pub js_wasm_enabled: bool,
302    pub js_wasm_ion_enabled: bool,
303    // feature: Largest Contentful Paint | #42000 | Web/API/LargestContentfulPaint
304    pub largest_contentful_paint_enabled: bool,
305    pub layout_animations_test_enabled: bool,
306    // feature: CSS Multicol | #22397 | Web/CSS/Guides/Multicol_layout
307    pub layout_columns_enabled: bool,
308    pub layout_flexbox_balance: bool,
309    // feature: CSS Grid | #34479 | Web/CSS/Guides/Grid_layout
310    pub layout_grid_enabled: bool,
311    pub layout_container_queries_enabled: bool,
312    pub layout_css_alpha_color_function_enabled: bool,
313    pub layout_css_ellipse_corners_enabled: bool,
314    pub layout_css_progress_function_enabled: bool,
315    pub layout_style_sharing_cache_enabled: bool,
316    pub layout_threads: i64,
317    /// The minimum number of parallelizable jobs required before turning on parallelism
318    /// for a set of jobs.
319    ///
320    /// When deciding whether or not to parallelize layout, this is the minimum number of
321    /// jobs that must be larger than [`Self::layout_parallelism_job_size_minimum`] to
322    /// turn on parallelism. An exception is when doing box tree layout, where Servo does
323    /// not know the depth of the tree. In that case any task that has more jobs than this
324    /// value will be parallelized.
325    ///
326    /// The goal of these two values is to allow tuning Servo's parallelism for both wide
327    /// and deep trees.
328    pub layout_parallelism_job_count_minimum: u64,
329    /// The minimum size of a layout job to be considered for parallelization.
330    ///
331    /// When deciding whether or not to parallelize layout, jobs greater than this size
332    /// are counted when considering the [`Self::layout_parallelism_job_count_minimum`]
333    /// threshold for turning on parallelism. Generally the size of the job is based on
334    /// the number of tasks to process in the subtree. For instance, this might be the
335    /// number of boxes to process in a box tree subtree.
336    ///
337    /// The goal of these two values is to allow tuning Servo's parallelism for both wide
338    /// and deep trees.
339    pub layout_parallelism_job_size_minimum: u64,
340    pub layout_unimplemented: bool,
341    // feature: Variable fonts | #38800 | Web/CSS/Guides/Fonts/Variable_fonts
342    pub layout_variable_fonts_enabled: bool,
343    // feature: CSS writing modes | #2560 | Web/CSS/Guides/Writing_modes
344    pub layout_writing_mode_enabled: bool,
345    /// Enable hardware acceleration for video playback.
346    pub media_glvideo_enabled: bool,
347    /// Enable a non-standard event handler for verifying behavior of media elements during tests.
348    pub media_testing_enabled: bool,
349    /// The default timeout set for establishing a network connection in seconds. This amount
350    /// if for the entire process of connecting to an address. For instance, if a particular host is
351    /// associated with multiple IP addresses, this timeout will be divided equally among
352    /// each IP address.
353    pub network_connection_timeout: u64,
354    pub network_enforce_tls_enabled: bool,
355    pub network_enforce_tls_localhost: bool,
356    pub network_enforce_tls_onion: bool,
357    pub network_http_cache_disabled: bool,
358    /// The path to a disk cache file. Empty string disables the disk cache.
359    pub network_http_disk_cache: String,
360    /// Maximum size of the disk cache file in bytes.
361    pub network_http_disk_cache_size: u64,
362    /// A url for a http proxy. We treat an empty string as no proxy.
363    pub network_http_proxy_uri: String,
364    /// A url for a https proxy. We treat an empty string as no proxy.
365    pub network_https_proxy_uri: String,
366    /// The domains for which we will not have a proxy. No effect if `network_http_proxy_uri` is not set.
367    /// The exact behavior is given by
368    /// <https://docs.rs/hyper-util/latest/hyper_util/client/proxy/matcher/struct.Builder.html#method.no>
369    pub network_http_no_proxy: String,
370    /// The weight of the http memory cache
371    /// Notice that this is not equal to the number of different urls in the cache.
372    pub network_http_cache_size: u64,
373    pub network_local_directory_listing_enabled: bool,
374    /// Force the use of `rust-webpki` verification for CA roots. If this is false (the
375    /// default), then `rustls-platform-verifier` will be used, except on Android where
376    /// `rust-webpki` is always used.
377    pub network_use_webpki_roots: bool,
378    /// The maximum content size we will forward for preallocation, defaults to 5MB
379    pub network_max_content_length: u64,
380    /// Experimental option. If enabled servo will attempt to optimize thread placement
381    /// and/or priority of critical servo threads to optimize performance.
382    #[doc(hidden)]
383    pub perf_thread_boost_enabled: bool,
384    /// The length of the session history, in navigations, for each `WebView. Back-forward
385    /// cache entries that are more than `session_history_max_length` steps in the future or
386    /// `session_history_max_length` steps in the past will be discarded. Navigating forward
387    /// or backward to that entry will cause the entire page to be reloaded.
388    pub session_history_max_length: i64,
389    /// The background color of shell's viewport. This will be used by OpenGL's `glClearColor`.
390    pub shell_background_color_rgba: [f64; 4],
391    pub webgl_testing_context_creation_error: bool,
392    /// Maximum number of workers for the main thread pool
393    pub thread_pool_workers_max: u64,
394    /// Number of workers per thread pool, if we fail to detect how much
395    /// parallelism is available at runtime.
396    pub thread_pool_fallback_workers: u64,
397    /// Maximum number of workers for the asynchronous networking runtime thread pool
398    pub thread_pool_async_runtime_workers_max: u64,
399    /// Number of worker threads used to rasterize a canvas.
400    /// This preference currently only affects the vello_cpu backend.
401    /// Setting this pref to `0` uses the single-threaded backend and
402    /// avoids creating a threadpool.
403    /// For small canvas sizes this pref is ignored and no threadpool is created.
404    pub thread_pool_canvas_workers: u64,
405    /// Maximum number of workers for WebRender
406    pub thread_pool_webrender_workers_max: u64,
407    /// The user-agent to use for Servo. This can also be set via [`UserAgentPlatform`] in
408    /// order to set the value to the default value for the given platform.
409    pub user_agent: String,
410    /// Whether or not the viewport meta tag is enabled.
411    pub viewport_meta_enabled: bool,
412    pub log_filter: String,
413    /// Whether the accessibility code is enabled.
414    pub accessibility_enabled: bool,
415    /// Whether to run accessibility tree integrity checks, and any other expensive checks.
416    /// This should only be true in tests.
417    pub expensive_accessibility_test_assertions_enabled: bool,
418    /// Exposes internal JS API functions that are usually restricted to `about:...` pages
419    /// Useful if you want to get memory report or force GC in a test page
420    pub expose_servointernals_globally: bool,
421}
422
423impl Preferences {
424    const fn const_default() -> Self {
425        Self {
426            css_animations_testing_enabled: false,
427            editing_caret_blink_time: 600,
428            devtools_server_enabled: false,
429            devtools_server_listen_address: String::new(),
430            dom_adoptedstylesheet_enabled: false,
431            dom_allow_preloading_module_descendants: false,
432            dom_allow_scripts_to_close_windows: false,
433            dom_async_clipboard_enabled: false,
434            dom_bluetooth_enabled: false,
435            dom_bluetooth_testing_enabled: false,
436            dom_canvas_capture_enabled: false,
437            dom_canvas_text_enabled: true,
438            dom_canvas_backend: String::new(),
439            dom_canvas_msg_buffer_size: 16,
440            dom_composition_event_enabled: false,
441            dom_cookiestore_enabled: false,
442            dom_credential_management_enabled: false,
443            dom_crypto_subtle_enabled: true,
444            dom_document_dblclick_dist: 1,
445            dom_document_dblclick_timeout: 300,
446            dom_entries_api_enabled: false,
447            dom_exec_command_enabled: false,
448            dom_fontface_enabled: false,
449            dom_fullscreen_test: false,
450            dom_gamepad_enabled: true,
451            dom_geolocation_enabled: false,
452            dom_wakelock_enabled: false,
453            dom_indexeddb_enabled: false,
454            dom_intersection_observer_enabled: false,
455            dom_microdata_testing_enabled: false,
456            dom_navigator_protocol_handlers_enabled: false,
457            dom_notification_enabled: false,
458            dom_parallel_css_parsing_enabled: true,
459            dom_offscreen_canvas_enabled: false,
460            dom_permissions_enabled: false,
461            dom_permissions_testing_allowed_in_nonsecure_contexts: false,
462            dom_resize_observer_enabled: true,
463            dom_sanitizer_enabled: false,
464            dom_script_asynch: true,
465            dom_storage_manager_api_enabled: false,
466            dom_serviceworker_enabled: false,
467            dom_serviceworker_timeout_seconds: 60,
468            dom_sharedworker_enabled: true,
469            dom_servo_helpers_enabled: false,
470            dom_servoparser_async_html_tokenizer_enabled: false,
471            dom_testbinding_enabled: false,
472            dom_testbinding_prefcontrolled2_enabled: false,
473            dom_testbinding_prefcontrolled_enabled: false,
474            dom_testbinding_preference_value_falsy: false,
475            dom_testbinding_preference_value_quote_string_test: String::new(),
476            dom_testbinding_preference_value_space_string_test: String::new(),
477            dom_testbinding_preference_value_string_empty: String::new(),
478            dom_testbinding_preference_value_string_test: String::new(),
479            dom_testbinding_preference_value_truthy: false,
480            dom_testing_element_activation_enabled: false,
481            dom_testing_html_input_element_select_files_enabled: false,
482            dom_testperf_enabled: false,
483            dom_testutils_enabled: false,
484            // Following Firefox and Chrome, we are enabling the touch events legacy APIs for android.
485            // Additionally, enabling it in ohos for compatibility as well.
486            dom_touch_events_legacy_apis_enabled: cfg!(target_os = "android") |
487                cfg!(target_env = "ohos"),
488            dom_transient_activation_duration_ms: 5000,
489            dom_web_animations_enabled: false,
490            dom_webgl2_enabled: false,
491            dom_webgpu_enabled: false,
492            dom_webgpu_wgpu_backend: String::new(),
493            dom_webrtc_enabled: false,
494            dom_webrtc_transceiver_enabled: false,
495            dom_webxr_enabled: true,
496            dom_webxr_first_person_observer_view: false,
497            dom_webxr_glwindow_cubemap: false,
498            dom_webxr_glwindow_enabled: true,
499            dom_webxr_glwindow_left_right: false,
500            dom_webxr_glwindow_red_cyan: false,
501            dom_webxr_glwindow_spherical: false,
502            dom_webxr_hands_enabled: true,
503            dom_webxr_layers_enabled: false,
504            dom_webxr_openxr_enabled: true,
505            dom_webxr_sessionavailable: false,
506            dom_webxr_test: false,
507            dom_webxr_unsafe_assume_user_intent: false,
508            dom_worklet_blockingsleep_enabled: false,
509            dom_worklet_enabled: false,
510            dom_worklet_testing_enabled: false,
511            dom_worklet_timeout_ms: 10,
512            dom_visual_viewport_enabled: false,
513            accessibility_enabled: false,
514            expensive_accessibility_test_assertions_enabled: false,
515            fonts_default: String::new(),
516            fonts_default_monospace_size: 13,
517            fonts_default_size: 16,
518            fonts_monospace: String::new(),
519            fonts_sans_serif: String::new(),
520            fonts_serif: String::new(),
521            gfx_precache_shaders: false,
522            gfx_text_antialiasing_enabled: true,
523            gfx_subpixel_text_antialiasing_enabled: true,
524            gfx_texture_swizzling_enabled: true,
525            image_key_batch_size: 10,
526            inspector_show_servo_internal_shadow_roots: false,
527            intl_locale_override: String::new(),
528            js_asmjs_enabled: true,
529            js_baseline_interpreter_enabled: true,
530            js_baseline_jit_enabled: true,
531            js_baseline_jit_unsafe_eager_compilation_enabled: false,
532            js_disable_jit: false,
533            js_ion_enabled: true,
534            js_ion_unsafe_eager_compilation_enabled: false,
535            // The layout system currently does not work with compacting GC, so it is disabled by default.
536            // See https://github.com/servo/servo/issues/47577
537            js_mem_gc_compacting_enabled: false,
538            js_mem_gc_empty_chunk_count_min: 1,
539            js_mem_gc_high_frequency_heap_growth_max: 300,
540            js_mem_gc_high_frequency_heap_growth_min: 150,
541            js_mem_gc_high_frequency_high_limit_mb: 500,
542            js_mem_gc_high_frequency_low_limit_mb: 100,
543            js_mem_gc_high_frequency_time_limit_ms: 1000,
544            js_mem_gc_incremental_enabled: false,
545            js_mem_gc_incremental_slice_ms: 10,
546            js_mem_gc_low_frequency_heap_growth: 150,
547            js_mem_gc_malloc_threshold_base_mb: 38,
548            js_mem_gc_per_zone_enabled: false,
549            js_mem_gc_urgent_threshold_mb: 16,
550            js_mem_gc_zeal_frequency: 100,
551            js_mem_gc_zeal_level: 0,
552            js_mem_max: -1,
553            js_native_regex_enabled: true,
554            js_offthread_compilation_enabled: true,
555            js_timers_minimum_duration: 1000,
556            js_wasm_baseline_enabled: true,
557            js_wasm_enabled: true,
558            js_wasm_ion_enabled: true,
559            largest_contentful_paint_enabled: false,
560            layout_animations_test_enabled: false,
561            layout_columns_enabled: false,
562            layout_container_queries_enabled: false,
563            layout_css_alpha_color_function_enabled: false,
564            layout_css_ellipse_corners_enabled: false,
565            layout_css_progress_function_enabled: false,
566            layout_flexbox_balance: false,
567            layout_grid_enabled: true,
568            layout_style_sharing_cache_enabled: true,
569            // TODO(mrobinson): This should likely be based on the number of processors.
570            layout_threads: 3,
571            layout_parallelism_job_count_minimum: 4,
572            layout_parallelism_job_size_minimum: 16,
573            layout_unimplemented: false,
574            layout_variable_fonts_enabled: false,
575            layout_writing_mode_enabled: false,
576            media_glvideo_enabled: false,
577            media_testing_enabled: false,
578            network_connection_timeout: 15,
579            network_enforce_tls_enabled: false,
580            network_enforce_tls_localhost: false,
581            network_enforce_tls_onion: false,
582            network_http_cache_disabled: false,
583            network_http_disk_cache: String::new(),
584            network_http_disk_cache_size: 1024 * 1024 * 100, // Roughtly 100MB
585            network_http_proxy_uri: String::new(),
586            network_https_proxy_uri: String::new(),
587            network_http_no_proxy: String::new(),
588            network_http_cache_size: 5000,
589            network_local_directory_listing_enabled: true,
590            network_use_webpki_roots: false,
591            network_max_content_length: 5 * 1024 * 1024,
592            perf_thread_boost_enabled: true,
593            session_history_max_length: 20,
594            shell_background_color_rgba: [1.0, 1.0, 1.0, 1.0],
595            log_filter: String::new(),
596            thread_pool_workers_max: 4,
597            thread_pool_async_runtime_workers_max: 6,
598            thread_pool_fallback_workers: 3,
599            // <https://github.com/linebender/vello/blob/c95b228e1cf73bf96338e8c8ae0d145553f8f99c/sparse_strips/vello_cpu/examples/basic.rs#L51>
600            // According to this example 2-4 give the best results.
601            thread_pool_canvas_workers: 3,
602            thread_pool_webrender_workers_max: 4,
603            webgl_testing_context_creation_error: false,
604            user_agent: String::new(),
605            viewport_meta_enabled: false,
606            expose_servointernals_globally: false,
607        }
608    }
609
610    /// The amount of time that a half cycle of a text caret blink takes. If blinking is disabled
611    /// this returns `None`.
612    pub fn editing_caret_blink_time(&self) -> Option<Duration> {
613        if self.editing_caret_blink_time > 0 {
614            Some(Duration::from_millis(self.editing_caret_blink_time as u64))
615        } else {
616            None
617        }
618    }
619}
620
621impl Default for Preferences {
622    fn default() -> Self {
623        let mut preferences = Self::const_default();
624        preferences.user_agent = UserAgentPlatform::default().to_user_agent_string();
625        if let Ok(proxy_uri) = std::env::var("http_proxy").or_else(|_| std::env::var("HTTP_PROXY"))
626        {
627            preferences.network_http_proxy_uri = proxy_uri;
628        }
629        if let Ok(proxy_uri) =
630            std::env::var("https_proxy").or_else(|_| std::env::var("HTTPS_PROXY"))
631        {
632            preferences.network_https_proxy_uri = proxy_uri;
633        }
634        if let Ok(no_proxy) = std::env::var("no_proxy").or_else(|_| std::env::var("NO_PROXY")) {
635            preferences.network_http_no_proxy = no_proxy
636        }
637
638        preferences
639    }
640}
641
642pub enum UserAgentPlatform {
643    Desktop,
644    Android,
645    OpenHarmony,
646    Ios,
647}
648
649impl UserAgentPlatform {
650    /// Return the default `UserAgentPlatform` for this platform. This is
651    /// not an implementation of `Default` so that it can be `const`.
652    pub const fn default() -> Self {
653        if cfg!(target_os = "android") {
654            Self::Android
655        } else if cfg!(target_env = "ohos") {
656            Self::OpenHarmony
657        } else if cfg!(target_os = "ios") {
658            Self::Ios
659        } else {
660            Self::Desktop
661        }
662    }
663}
664
665impl UserAgentPlatform {
666    /// Convert this [`UserAgentPlatform`] into its corresponding `String` value, ie the
667    /// default user-agent to use for this platform.
668    pub fn to_user_agent_string(&self) -> String {
669        const SERVO_VERSION: &str = env!("CARGO_PKG_VERSION");
670        match self {
671            UserAgentPlatform::Desktop
672                if cfg!(all(target_os = "windows", target_arch = "x86_64")) =>
673            {
674                format!(
675                    "Mozilla/5.0 (Windows NT 10.0; Win64; {ARCH}; rv:153.0) Servo/{SERVO_VERSION} Firefox/153.0"
676                )
677            },
678            UserAgentPlatform::Desktop if cfg!(target_os = "macos") => {
679                format!(
680                    "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:153.0) Servo/{SERVO_VERSION} Firefox/153.0"
681                )
682            },
683            UserAgentPlatform::Desktop => {
684                format!(
685                    "Mozilla/5.0 (X11; Linux {ARCH}; rv:153.0) Servo/{SERVO_VERSION} Firefox/153.0"
686                )
687            },
688            UserAgentPlatform::Android => {
689                format!(
690                    "Mozilla/5.0 (Android 10; Mobile; rv:153.0) Servo/{SERVO_VERSION} Firefox/153.0"
691                )
692            },
693            UserAgentPlatform::OpenHarmony => format!(
694                "Mozilla/5.0 (OpenHarmony; Mobile; rv:153.0) Servo/{SERVO_VERSION} Firefox/153.0"
695            ),
696            UserAgentPlatform::Ios => format!(
697                "Mozilla/5.0 (iPhone; CPU iPhone OS 18_6 like Mac OS X; rv:153.0) Servo/{SERVO_VERSION} Firefox/153.0"
698            ),
699        }
700    }
701}
servo_config/prefs.rs

servo_config/
prefs.rs
