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

servo_config/
prefs.rs
