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/dom/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.attr.enabled",
62        preferences.layout_css_attr_enabled
63    );
64    stylo_static_prefs::set_pref!(
65        "layout.css.ellipse-corners.enabled",
66        preferences.layout_css_ellipse_corners_enabled
67    );
68    stylo_static_prefs::set_pref!(
69        "layout.css.progress-function.enabled",
70        preferences.layout_css_progress_function_enabled
71    );
72    stylo_static_prefs::set_pref!(
73        "layout.writing-mode.enabled",
74        preferences.layout_writing_mode_enabled
75    );
76    stylo_static_prefs::set_pref!(
77        "layout.container-queries.enabled",
78        preferences.layout_container_queries_enabled
79    );
80    stylo_static_prefs::set_pref!(
81        "layout.variable_fonts.enabled",
82        preferences.layout_variable_fonts_enabled
83    );
84
85    *PREFERENCES.write().unwrap() = preferences;
86
87    for observer in &*OBSERVERS.read().unwrap() {
88        observer.prefs_changed(&changed);
89    }
90}
91
92/// A convenience macro for accessing a preference value using its static path.
93/// Passing an invalid path is a compile-time error.
94#[macro_export]
95macro_rules! pref {
96    ($name: ident) => {
97        $crate::prefs::get().$name.clone()
98    };
99}
100
101/// The set of global preferences supported by Servo.
102///
103/// Each preference has a default value that determines its initial state. These defaults
104/// fall into roughly three categories:
105/// - **Stable**: enabled by default.
106/// - **Experimental**: disabled by default, but intended to be enabled for experimental use.
107/// - **Unstable**: disabled by default.
108///
109/// For a full overview of which preferences are experimental, see the
110/// [experimental features documentation](https://book.servo.org/design-documentation/experimental-features.html).
111#[derive(Clone, Deserialize, Serialize, ServoPreferences)]
112pub struct Preferences {
113    pub fonts_default: String,
114    pub fonts_serif: String,
115    pub fonts_sans_serif: String,
116    pub fonts_monospace: String,
117    pub fonts_default_size: i64,
118    pub fonts_default_monospace_size: i64,
119    /// The amount of time that a half cycle of a text caret blink takes in milliseconds.
120    /// If this value is less than or equal to zero, then caret blink is disabled.
121    pub editing_caret_blink_time: i64,
122    pub css_animations_testing_enabled: bool,
123    /// Start the devtools server at startup
124    pub devtools_server_enabled: bool,
125    /// The address:port the devtools server listens to, default to 127.0.0.1:7000.
126    pub devtools_server_listen_address: String,
127    // feature: WebGPU | #24706 | Web/API/WebGPU_API
128    pub dom_webgpu_enabled: bool,
129    /// List of comma-separated backends to be used by wgpu.
130    pub dom_webgpu_wgpu_backend: String,
131    // feature: Adopted Stylesheet | #38132 | Web/API/Document/adoptedStyleSheets
132    pub dom_adoptedstylesheet_enabled: bool,
133    pub dom_allow_preloading_module_descendants: bool,
134    // feature: Clipboard API | #36084 | Web/API/Clipboard_API
135    pub dom_async_clipboard_enabled: bool,
136    pub dom_bluetooth_enabled: bool,
137    pub dom_bluetooth_testing_enabled: bool,
138    pub dom_allow_scripts_to_close_windows: bool,
139    // feature: Media Capture and Streams API | #26861 | Web/API/Media_Capture_and_Streams_API
140    pub dom_canvas_capture_enabled: bool,
141    pub dom_canvas_text_enabled: bool,
142    /// Selects canvas backend
143    ///
144    /// Available values:
145    /// - vello
146    /// - Everything else selects vello_cpu
147    pub dom_canvas_backend: String,
148    /// Maximum number of buffered canvas commands before an automatic flush is triggered.
149    ///
150    /// A lower value keeps the paint thread fed with work (better parallelism),
151    /// while a higher value improves batching efficiency (fewer channel operations, lower power).
152    ///
153    /// See <https://github.com/servo/servo/pull/45301> for measurements.
154    pub dom_canvas_msg_buffer_size: u64,
155    pub dom_composition_event_enabled: bool,
156    // feature: CookieStore | #37674 | Web/API/CookieStore
157    pub dom_cookiestore_enabled: bool,
158    // feature: Credential Management API | #38788 | Web/API/Credential_Management_API
159    pub dom_credential_management_enabled: bool,
160    // feature: WebCrypto API | #40687 | Web/API/Web_Crypto_API
161    pub dom_crypto_subtle_enabled: bool,
162    pub dom_document_dblclick_timeout: i64,
163    pub dom_document_dblclick_dist: i64,
164    // feature: File and Directory Entries API | #45653 | Web/API/File_and_Directory_Entries_API
165    pub dom_entries_api_enabled: bool,
166    // feature: Document.execCommand | #25005 | Web/API/Document/execCommand
167    pub dom_exec_command_enabled: bool,
168    // feature: CSS Font Loading API | #29376 | Web/API/CSS_Font_Loading_API
169    pub dom_fontface_enabled: bool,
170    pub dom_fullscreen_test: bool,
171    // feature: Gamepad API | #10977 | Web/API/Gamepad_API
172    pub dom_gamepad_enabled: bool,
173    // feature: Geolocation API | #38903 | Web/API/Geolocation_API
174    pub dom_geolocation_enabled: bool,
175    // feature: Screen Wake Lock API | #43615 | Web/API/Screen_Wake_Lock_API
176    pub dom_wakelock_enabled: bool,
177    // feature: IndexedDB | #6963 | Web/API/IndexedDB_API
178    pub dom_indexeddb_enabled: bool,
179    // feature: IntersectionObserver | #35767 | Web/API/Intersection_Observer_API
180    pub dom_intersection_observer_enabled: bool,
181    pub dom_microdata_testing_enabled: bool,
182    // feature: Navigator.registerProtocolHandler() | #40615 | Web/API/Navigator/registerProtocolHandler
183    pub dom_navigator_protocol_handlers_enabled: bool,
184    // feature: Notification API | #34841 | Web/API/Notifications_API
185    pub dom_notification_enabled: bool,
186    // feature: OffscreenCanvas | #34111 | Web/API/OffscreenCanvas
187    pub dom_offscreen_canvas_enabled: bool,
188    pub dom_parallel_css_parsing_enabled: bool,
189    // feature: Permissions API | #31235 | Web/API/Permissions_API
190    pub dom_permissions_enabled: bool,
191    pub dom_permissions_testing_allowed_in_nonsecure_contexts: bool,
192    // feature: ResizeObserver | #39790 | Web/API/ResizeObserver
193    pub dom_resize_observer_enabled: bool,
194    // feature: Sanitizer API | #43948 | Web/API/HTML_Sanitizer_API
195    pub dom_sanitizer_enabled: bool,
196    pub dom_script_asynch: bool,
197    // feature: Storage API | #43976 | Web/API/Storage_API
198    pub dom_storage_manager_api_enabled: bool,
199    // feature: ServiceWorker | #36538 | Web/API/Service_Worker_API
200    pub dom_serviceworker_enabled: bool,
201    pub dom_serviceworker_timeout_seconds: i64,
202    // feature: SharedWorker | #7458 | Web/API/SharedWorker
203    pub dom_sharedworker_enabled: bool,
204    pub dom_servo_helpers_enabled: bool,
205    pub dom_servoparser_async_html_tokenizer_enabled: bool,
206    pub dom_testbinding_enabled: bool,
207    pub dom_testbinding_prefcontrolled_enabled: bool,
208    pub dom_testbinding_prefcontrolled2_enabled: bool,
209    pub dom_testbinding_preference_value_falsy: bool,
210    pub dom_testbinding_preference_value_quote_string_test: String,
211    pub dom_testbinding_preference_value_space_string_test: String,
212    pub dom_testbinding_preference_value_string_empty: String,
213    pub dom_testbinding_preference_value_string_test: String,
214    pub dom_testbinding_preference_value_truthy: bool,
215    pub dom_testing_element_activation_enabled: bool,
216    pub dom_testing_html_input_element_select_files_enabled: bool,
217    pub dom_testperf_enabled: bool,
218    // https://testutils.spec.whatwg.org#availability
219    pub dom_testutils_enabled: bool,
220    /// <https://w3c.github.io/touch-events/#conditionally-exposing-legacy-touch-event-apis>
221    pub dom_touch_events_legacy_apis_enabled: bool,
222    /// <https://html.spec.whatwg.org/multipage/#transient-activation-duration>
223    pub dom_transient_activation_duration_ms: i64,
224    // feature: Web Animations | #36950 | Web/API/Web_Animations_API
225    pub dom_web_animations_enabled: bool,
226    /// Enable WebGL2 APIs.
227    // feature: WebGL2 | #41394 | Web/API/WebGL2RenderingContext
228    pub dom_webgl2_enabled: bool,
229    // feature: WebRTC | #41396 | Web/API/WebRTC_API
230    pub dom_webrtc_enabled: bool,
231    // feature: WebRTC Transceiver | #41396 | Web/API/RTCRtpTransceiver
232    pub dom_webrtc_transceiver_enabled: bool,
233    pub dom_webxr_enabled: bool,
234    pub dom_webxr_test: bool,
235    pub dom_webxr_first_person_observer_view: bool,
236    pub dom_webxr_glwindow_enabled: bool,
237    pub dom_webxr_glwindow_left_right: bool,
238    pub dom_webxr_glwindow_red_cyan: bool,
239    pub dom_webxr_glwindow_spherical: bool,
240    pub dom_webxr_glwindow_cubemap: bool,
241    pub dom_webxr_hands_enabled: bool,
242    // feature: WebXR Layers | #27468 | Web/API/XRCompositionLayer
243    pub dom_webxr_layers_enabled: bool,
244    pub dom_webxr_openxr_enabled: bool,
245    pub dom_webxr_sessionavailable: bool,
246    pub dom_webxr_unsafe_assume_user_intent: bool,
247    pub dom_worklet_enabled: bool,
248    pub dom_worklet_blockingsleep_enabled: bool,
249    pub dom_worklet_testing_enabled: bool,
250    pub dom_worklet_timeout_ms: i64,
251    /// <https://drafts.csswg.org/cssom-view/#the-visualviewport-interface>
252    // feature: VisualViewport | #41341 | Web/API/VisualViewport
253    pub dom_visual_viewport_enabled: bool,
254    /// True to compile all WebRender shaders when Servo initializes. This is mostly
255    /// useful when modifying the shaders, to ensure they all compile after each change is
256    /// made.
257    pub gfx_precache_shaders: bool,
258    /// Whether or not antialiasing is enabled for text rendering.
259    pub gfx_text_antialiasing_enabled: bool,
260    /// Whether or not subpixel antialiasing is enabled for text rendering.
261    pub gfx_subpixel_text_antialiasing_enabled: bool,
262    pub gfx_texture_swizzling_enabled: bool,
263    /// The amount of image keys we request per batch for the image cache.
264    pub image_key_batch_size: i64,
265    /// Whether or not the DOM inspector should show shadow roots of user-agent shadow trees
266    pub inspector_show_servo_internal_shadow_roots: bool,
267    /// A locale tag (eg. es-ES) to use for language negotiation instead of the system locale.
268    /// An empty string represents no override.
269    /// TODO: Option<> support in PrefValue
270    pub intl_locale_override: String,
271    pub js_asmjs_enabled: bool,
272    pub js_baseline_interpreter_enabled: bool,
273    /// Whether to disable the jit within SpiderMonkey
274    pub js_disable_jit: bool,
275    pub js_baseline_jit_enabled: bool,
276    pub js_baseline_jit_unsafe_eager_compilation_enabled: bool,
277    pub js_ion_enabled: bool,
278    pub js_ion_unsafe_eager_compilation_enabled: bool,
279    pub js_mem_gc_compacting_enabled: bool,
280    pub js_mem_gc_empty_chunk_count_min: i64,
281    pub js_mem_gc_high_frequency_heap_growth_max: i64,
282    pub js_mem_gc_high_frequency_heap_growth_min: i64,
283    pub js_mem_gc_high_frequency_high_limit_mb: i64,
284    pub js_mem_gc_high_frequency_low_limit_mb: i64,
285    pub js_mem_gc_high_frequency_time_limit_ms: i64,
286    /// Whether or not incremental garbage collection is turned on. This is currently
287    /// turned off by default as pre-barriers are not implemented yet. If turned on, it
288    /// will likely lead to memory corruption.
289    ///
290    /// See <https://github.com/servo/servo/issues/7621>.
291    pub js_mem_gc_incremental_enabled: bool,
292    pub js_mem_gc_incremental_slice_ms: i64,
293    pub js_mem_gc_low_frequency_heap_growth: i64,
294    pub js_mem_gc_per_zone_enabled: bool,
295    pub js_mem_gc_zeal_frequency: i64,
296    pub js_mem_gc_zeal_level: i64,
297    pub js_mem_max: i64,
298    pub js_native_regex_enabled: bool,
299    pub js_offthread_compilation_enabled: bool,
300    pub js_timers_minimum_duration: i64,
301    pub js_wasm_baseline_enabled: bool,
302    pub js_wasm_enabled: bool,
303    pub js_wasm_ion_enabled: bool,
304    // feature: Largest Contentful Paint | #42000 | Web/API/LargestContentfulPaint
305    pub largest_contentful_paint_enabled: bool,
306    pub layout_animations_test_enabled: bool,
307    // feature: CSS Multicol | #22397 | Web/CSS/Guides/Multicol_layout
308    pub layout_columns_enabled: 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_attr_enabled: bool,
314    pub layout_css_ellipse_corners_enabled: bool,
315    pub layout_css_progress_function_enabled: bool,
316    pub layout_style_sharing_cache_enabled: bool,
317    pub layout_threads: i64,
318    /// The minimum number of parallelizable jobs required before turning on parallelism
319    /// for a set of jobs.
320    ///
321    /// When deciding whether or not to parallelize layout, this is the minimum number of
322    /// jobs that must be larger than [`Self::layout_parallelism_job_size_minimum`] to
323    /// turn on parallelism. An exception is when doing box tree layout, where Servo does
324    /// not know the depth of the tree. In that case any task that has more jobs than this
325    /// value will be parallelized.
326    ///
327    /// The goal of these two values is to allow tuning Servo's parallelism for both wide
328    /// and deep trees.
329    pub layout_parallelism_job_count_minimum: u64,
330    /// The minimum size of a layout job to be considered for parallelization.
331    ///
332    /// When deciding whether or not to parallelize layout, jobs greater than this size
333    /// are counted when considering the [`Self::layout_parallelism_job_count_minimum`]
334    /// threshold for turning on parallelism. Generally the size of the job is based on
335    /// the number of tasks to process in the subtree. For instance, this might be the
336    /// number of boxes to process in a box tree subtree.
337    ///
338    /// The goal of these two values is to allow tuning Servo's parallelism for both wide
339    /// and deep trees.
340    pub layout_parallelism_job_size_minimum: u64,
341    pub layout_unimplemented: bool,
342    // feature: Variable fonts | #38800 | Web/CSS/Guides/Fonts/Variable_fonts
343    pub layout_variable_fonts_enabled: bool,
344    // feature: CSS writing modes | #2560 | Web/CSS/Guides/Writing_modes
345    pub layout_writing_mode_enabled: bool,
346    /// Enable hardware acceleration for video playback.
347    pub media_glvideo_enabled: bool,
348    /// Enable a non-standard event handler for verifying behavior of media elements during tests.
349    pub media_testing_enabled: bool,
350    /// The default timeout set for establishing a network connection in seconds. This amount
351    /// if for the entire process of connecting to an address. For instance, if a particular host is
352    /// associated with multiple IP addresses, this timeout will be divided equally among
353    /// each IP address.
354    pub network_connection_timeout: u64,
355    pub network_enforce_tls_enabled: bool,
356    pub network_enforce_tls_localhost: bool,
357    pub network_enforce_tls_onion: bool,
358    pub network_http_cache_disabled: bool,
359    /// The path to a disk cache file. Empty string disables the disk cache.
360    pub network_http_disk_cache: String,
361    /// Maximum size of the disk cache file in bytes.
362    pub network_http_disk_cache_size: u64,
363    /// A url for a http proxy. We treat an empty string as no proxy.
364    pub network_http_proxy_uri: String,
365    /// A url for a https proxy. We treat an empty string as no proxy.
366    pub network_https_proxy_uri: String,
367    /// The domains for which we will not have a proxy. No effect if `network_http_proxy_uri` is not set.
368    /// The exact behavior is given by
369    /// <https://docs.rs/hyper-util/latest/hyper_util/client/proxy/matcher/struct.Builder.html#method.no>
370    pub network_http_no_proxy: String,
371    /// The weight of the http memory cache
372    /// Notice that this is not equal to the number of different urls in the cache.
373    pub network_http_cache_size: u64,
374    pub network_local_directory_listing_enabled: bool,
375    /// Force the use of `rust-webpki` verification for CA roots. If this is false (the
376    /// default), then `rustls-platform-verifier` will be used, except on Android where
377    /// `rust-webpki` is always used.
378    pub network_use_webpki_roots: bool,
379    /// The maximum content size we will forward for preallocation, defaults to 5MB
380    pub network_max_content_length: u64,
381    /// Experimental option. If enabled servo will attempt to optimize thread placement
382    /// and/or priority of critical servo threads to optimize performance.
383    #[doc(hidden)]
384    pub perf_thread_boost_enabled: bool,
385    /// The length of the session history, in navigations, for each `WebView. Back-forward
386    /// cache entries that are more than `session_history_max_length` steps in the future or
387    /// `session_history_max_length` steps in the past will be discarded. Navigating forward
388    /// or backward to that entry will cause the entire page to be reloaded.
389    pub session_history_max_length: i64,
390    /// The background color of shell's viewport. This will be used by OpenGL's `glClearColor`.
391    pub shell_background_color_rgba: [f64; 4],
392    pub webgl_testing_context_creation_error: bool,
393    /// Maximum number of workers for the main thread pool
394    pub thread_pool_workers_max: u64,
395    /// Number of workers per thread pool, if we fail to detect how much
396    /// parallelism is available at runtime.
397    pub thread_pool_fallback_workers: u64,
398    /// Maximum number of workers for the asynchronous networking runtime thread pool
399    pub thread_pool_async_runtime_workers_max: u64,
400    /// Number of worker threads used to rasterize a canvas.
401    /// This preference currently only affects the vello_cpu backend.
402    /// Setting this pref to `0` uses the single-threaded backend and
403    /// avoids creating a threadpool.
404    /// For small canvas sizes this pref is ignored and no threadpool is created.
405    pub thread_pool_canvas_workers: u64,
406    /// Maximum number of workers for WebRender
407    pub thread_pool_webrender_workers_max: u64,
408    /// The user-agent to use for Servo. This can also be set via [`UserAgentPlatform`] in
409    /// order to set the value to the default value for the given platform.
410    pub user_agent: String,
411    /// Whether or not the viewport meta tag is enabled.
412    pub viewport_meta_enabled: bool,
413    pub log_filter: String,
414    /// Whether the accessibility code is enabled.
415    pub accessibility_enabled: bool,
416    /// Whether to run accessibility tree integrity checks, and any other expensive checks.
417    /// This should only be true in tests.
418    pub expensive_accessibility_test_assertions_enabled: bool,
419    /// Exposes internal JS API functions that are usually restricted to `about:...` pages
420    /// Useful if you want to get memory report or force GC in a test page
421    pub expose_servointernals_globally: bool,
422}
423
424impl Preferences {
425    const fn const_default() -> Self {
426        Self {
427            css_animations_testing_enabled: false,
428            editing_caret_blink_time: 600,
429            devtools_server_enabled: false,
430            devtools_server_listen_address: String::new(),
431            dom_adoptedstylesheet_enabled: false,
432            dom_allow_preloading_module_descendants: false,
433            dom_allow_scripts_to_close_windows: false,
434            dom_async_clipboard_enabled: false,
435            dom_bluetooth_enabled: false,
436            dom_bluetooth_testing_enabled: false,
437            dom_canvas_capture_enabled: false,
438            dom_canvas_text_enabled: true,
439            dom_canvas_backend: String::new(),
440            dom_canvas_msg_buffer_size: 16,
441            dom_composition_event_enabled: false,
442            dom_cookiestore_enabled: false,
443            dom_credential_management_enabled: false,
444            dom_crypto_subtle_enabled: true,
445            dom_document_dblclick_dist: 1,
446            dom_document_dblclick_timeout: 300,
447            dom_entries_api_enabled: false,
448            dom_exec_command_enabled: false,
449            dom_fontface_enabled: false,
450            dom_fullscreen_test: false,
451            dom_gamepad_enabled: true,
452            dom_geolocation_enabled: false,
453            dom_wakelock_enabled: false,
454            dom_indexeddb_enabled: false,
455            dom_intersection_observer_enabled: false,
456            dom_microdata_testing_enabled: false,
457            dom_navigator_protocol_handlers_enabled: false,
458            dom_notification_enabled: false,
459            dom_parallel_css_parsing_enabled: true,
460            dom_offscreen_canvas_enabled: false,
461            dom_permissions_enabled: false,
462            dom_permissions_testing_allowed_in_nonsecure_contexts: false,
463            dom_resize_observer_enabled: true,
464            dom_sanitizer_enabled: false,
465            dom_script_asynch: true,
466            dom_storage_manager_api_enabled: false,
467            dom_serviceworker_enabled: false,
468            dom_serviceworker_timeout_seconds: 60,
469            dom_sharedworker_enabled: true,
470            dom_servo_helpers_enabled: false,
471            dom_servoparser_async_html_tokenizer_enabled: false,
472            dom_testbinding_enabled: false,
473            dom_testbinding_prefcontrolled2_enabled: false,
474            dom_testbinding_prefcontrolled_enabled: false,
475            dom_testbinding_preference_value_falsy: false,
476            dom_testbinding_preference_value_quote_string_test: String::new(),
477            dom_testbinding_preference_value_space_string_test: String::new(),
478            dom_testbinding_preference_value_string_empty: String::new(),
479            dom_testbinding_preference_value_string_test: String::new(),
480            dom_testbinding_preference_value_truthy: false,
481            dom_testing_element_activation_enabled: false,
482            dom_testing_html_input_element_select_files_enabled: false,
483            dom_testperf_enabled: false,
484            dom_testutils_enabled: false,
485            // Following Firefox and Chrome, we are enabling the touch events legacy APIs for android.
486            // Additionally, enabling it in ohos for compatibility as well.
487            dom_touch_events_legacy_apis_enabled: cfg!(target_os = "android") |
488                cfg!(target_env = "ohos"),
489            dom_transient_activation_duration_ms: 5000,
490            dom_web_animations_enabled: false,
491            dom_webgl2_enabled: false,
492            dom_webgpu_enabled: false,
493            dom_webgpu_wgpu_backend: String::new(),
494            dom_webrtc_enabled: false,
495            dom_webrtc_transceiver_enabled: false,
496            dom_webxr_enabled: true,
497            dom_webxr_first_person_observer_view: false,
498            dom_webxr_glwindow_cubemap: false,
499            dom_webxr_glwindow_enabled: true,
500            dom_webxr_glwindow_left_right: false,
501            dom_webxr_glwindow_red_cyan: false,
502            dom_webxr_glwindow_spherical: false,
503            dom_webxr_hands_enabled: true,
504            dom_webxr_layers_enabled: false,
505            dom_webxr_openxr_enabled: true,
506            dom_webxr_sessionavailable: false,
507            dom_webxr_test: false,
508            dom_webxr_unsafe_assume_user_intent: false,
509            dom_worklet_blockingsleep_enabled: false,
510            dom_worklet_enabled: false,
511            dom_worklet_testing_enabled: false,
512            dom_worklet_timeout_ms: 10,
513            dom_visual_viewport_enabled: false,
514            accessibility_enabled: false,
515            expensive_accessibility_test_assertions_enabled: false,
516            fonts_default: String::new(),
517            fonts_default_monospace_size: 13,
518            fonts_default_size: 16,
519            fonts_monospace: String::new(),
520            fonts_sans_serif: String::new(),
521            fonts_serif: String::new(),
522            gfx_precache_shaders: false,
523            gfx_text_antialiasing_enabled: true,
524            gfx_subpixel_text_antialiasing_enabled: true,
525            gfx_texture_swizzling_enabled: true,
526            image_key_batch_size: 10,
527            inspector_show_servo_internal_shadow_roots: false,
528            intl_locale_override: String::new(),
529            js_asmjs_enabled: true,
530            js_baseline_interpreter_enabled: true,
531            js_baseline_jit_enabled: true,
532            js_baseline_jit_unsafe_eager_compilation_enabled: false,
533            js_disable_jit: false,
534            js_ion_enabled: true,
535            js_ion_unsafe_eager_compilation_enabled: false,
536            js_mem_gc_compacting_enabled: true,
537            js_mem_gc_empty_chunk_count_min: 1,
538            js_mem_gc_high_frequency_heap_growth_max: 300,
539            js_mem_gc_high_frequency_heap_growth_min: 150,
540            js_mem_gc_high_frequency_high_limit_mb: 500,
541            js_mem_gc_high_frequency_low_limit_mb: 100,
542            js_mem_gc_high_frequency_time_limit_ms: 1000,
543            js_mem_gc_incremental_enabled: false,
544            js_mem_gc_incremental_slice_ms: 10,
545            js_mem_gc_low_frequency_heap_growth: 150,
546            js_mem_gc_per_zone_enabled: false,
547            js_mem_gc_zeal_frequency: 100,
548            js_mem_gc_zeal_level: 0,
549            js_mem_max: -1,
550            js_native_regex_enabled: true,
551            js_offthread_compilation_enabled: true,
552            js_timers_minimum_duration: 1000,
553            js_wasm_baseline_enabled: true,
554            js_wasm_enabled: true,
555            js_wasm_ion_enabled: true,
556            largest_contentful_paint_enabled: false,
557            layout_animations_test_enabled: false,
558            layout_columns_enabled: false,
559            layout_container_queries_enabled: false,
560            layout_css_alpha_color_function_enabled: false,
561            layout_css_attr_enabled: false,
562            layout_css_ellipse_corners_enabled: false,
563            layout_css_progress_function_enabled: false,
564            layout_grid_enabled: true,
565            layout_style_sharing_cache_enabled: true,
566            // TODO(mrobinson): This should likely be based on the number of processors.
567            layout_threads: 3,
568            layout_parallelism_job_count_minimum: 4,
569            layout_parallelism_job_size_minimum: 16,
570            layout_unimplemented: false,
571            layout_variable_fonts_enabled: false,
572            layout_writing_mode_enabled: false,
573            media_glvideo_enabled: false,
574            media_testing_enabled: false,
575            network_connection_timeout: 15,
576            network_enforce_tls_enabled: false,
577            network_enforce_tls_localhost: false,
578            network_enforce_tls_onion: false,
579            network_http_cache_disabled: false,
580            network_http_disk_cache: String::new(),
581            network_http_disk_cache_size: 1024 * 1024 * 100, // Roughtly 100MB
582            network_http_proxy_uri: String::new(),
583            network_https_proxy_uri: String::new(),
584            network_http_no_proxy: String::new(),
585            network_http_cache_size: 5000,
586            network_local_directory_listing_enabled: true,
587            network_use_webpki_roots: false,
588            network_max_content_length: 5 * 1024 * 1024,
589            perf_thread_boost_enabled: true,
590            session_history_max_length: 20,
591            shell_background_color_rgba: [1.0, 1.0, 1.0, 1.0],
592            log_filter: String::new(),
593            thread_pool_workers_max: 4,
594            thread_pool_async_runtime_workers_max: 6,
595            thread_pool_fallback_workers: 3,
596            // <https://github.com/linebender/vello/blob/c95b228e1cf73bf96338e8c8ae0d145553f8f99c/sparse_strips/vello_cpu/examples/basic.rs#L51>
597            // According to this example 2-4 give the best results.
598            thread_pool_canvas_workers: 3,
599            thread_pool_webrender_workers_max: 4,
600            webgl_testing_context_creation_error: false,
601            user_agent: String::new(),
602            viewport_meta_enabled: false,
603            expose_servointernals_globally: false,
604        }
605    }
606
607    /// The amount of time that a half cycle of a text caret blink takes. If blinking is disabled
608    /// this returns `None`.
609    pub fn editing_caret_blink_time(&self) -> Option<Duration> {
610        if self.editing_caret_blink_time > 0 {
611            Some(Duration::from_millis(self.editing_caret_blink_time as u64))
612        } else {
613            None
614        }
615    }
616}
617
618impl Default for Preferences {
619    fn default() -> Self {
620        let mut preferences = Self::const_default();
621        preferences.user_agent = UserAgentPlatform::default().to_user_agent_string();
622        if let Ok(proxy_uri) = std::env::var("http_proxy").or_else(|_| std::env::var("HTTP_PROXY"))
623        {
624            preferences.network_http_proxy_uri = proxy_uri;
625        }
626        if let Ok(proxy_uri) =
627            std::env::var("https_proxy").or_else(|_| std::env::var("HTTPS_PROXY"))
628        {
629            preferences.network_https_proxy_uri = proxy_uri;
630        }
631        if let Ok(no_proxy) = std::env::var("no_proxy").or_else(|_| std::env::var("NO_PROXY")) {
632            preferences.network_http_no_proxy = no_proxy
633        }
634
635        preferences
636    }
637}
638
639pub enum UserAgentPlatform {
640    Desktop,
641    Android,
642    OpenHarmony,
643    Ios,
644}
645
646impl UserAgentPlatform {
647    /// Return the default `UserAgentPlatform` for this platform. This is
648    /// not an implementation of `Default` so that it can be `const`.
649    pub const fn default() -> Self {
650        if cfg!(target_os = "android") {
651            Self::Android
652        } else if cfg!(target_env = "ohos") {
653            Self::OpenHarmony
654        } else if cfg!(target_os = "ios") {
655            Self::Ios
656        } else {
657            Self::Desktop
658        }
659    }
660}
661
662impl UserAgentPlatform {
663    /// Convert this [`UserAgentPlatform`] into its corresponding `String` value, ie the
664    /// default user-agent to use for this platform.
665    pub fn to_user_agent_string(&self) -> String {
666        const SERVO_VERSION: &str = env!("CARGO_PKG_VERSION");
667        match self {
668            UserAgentPlatform::Desktop
669                if cfg!(all(target_os = "windows", target_arch = "x86_64")) =>
670            {
671                format!(
672                    "Mozilla/5.0 (Windows NT 10.0; Win64; {ARCH}rv:140.0) Servo/{SERVO_VERSION} Firefox/140.0"
673                )
674            },
675            UserAgentPlatform::Desktop if cfg!(target_os = "macos") => {
676                format!(
677                    "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:140.0) Servo/{SERVO_VERSION} Firefox/140.0"
678                )
679            },
680            UserAgentPlatform::Desktop => {
681                format!(
682                    "Mozilla/5.0 (X11; Linux {ARCH}; rv:140.0) Servo/{SERVO_VERSION} Firefox/140.0"
683                )
684            },
685            UserAgentPlatform::Android => {
686                format!(
687                    "Mozilla/5.0 (Android 10; Mobile; rv:140.0) Servo/{SERVO_VERSION} Firefox/140.0"
688                )
689            },
690            UserAgentPlatform::OpenHarmony => format!(
691                "Mozilla/5.0 (OpenHarmony; Mobile; rv:140.0) Servo/{SERVO_VERSION} Firefox/140.0"
692            ),
693            UserAgentPlatform::Ios => format!(
694                "Mozilla/5.0 (iPhone; CPU iPhone OS 18_6 like Mac OS X; rv:140.0) Servo/{SERVO_VERSION} Firefox/140.0"
695            ),
696        }
697    }
698}
servo_config/prefs.rs

servo_config/
prefs.rs
