net_traits/
image_cache.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
5use std::sync::Arc;
6
7use log::debug;
8use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
9use malloc_size_of_derive::MallocSizeOf;
10use paint_api::CrossProcessPaintApi;
11use pixels::{CorsStatus, ImageMetadata, RasterImage};
12use profile_traits::mem::Report;
13use resvg::usvg::{Font, fontdb};
14use serde::{Deserialize, Serialize};
15use servo_base::cross_process_instant::CrossProcessInstant;
16use servo_base::id::{PipelineId, WebViewId};
17use servo_url::{ImmutableOrigin, ServoUrl};
18use uuid::Uuid;
19use webrender_api::ImageKey;
20use webrender_api::units::DeviceIntSize;
21
22use crate::FetchResponseMsg;
23use crate::request::CorsSettings;
24
25// ======================================================================
26// Aux structs and enums.
27// ======================================================================
28
29/// An interface for resolving font families and styles for SVG images.
30pub trait FontResolver: Sync + Send + MallocSizeOf {
31    /// Attempt to resolve a font reference using the provided database of fonts.
32    /// Adding new fonts to the database is allowed. Return an index into the database
33    /// if the font resolves to an entry, otherwise return None.
34    fn resolve(&self, font: &Font, database: &mut Arc<fontdb::Database>) -> Option<fontdb::ID>;
35    /// Backup resolve. Find a font that can represent `char` and is not in `excluded`.
36    fn resolve_fallback(
37        &self,
38        char: char,
39        excluded: &[fontdb::ID],
40        database: &mut Arc<fontdb::Database>,
41    ) -> Option<fontdb::ID>;
42}
43
44pub type VectorImageId = PendingImageId;
45
46// Represents either a raster image for which the pixel data is available
47// or a vector image for which only the natural dimensions are available
48// and thus requires a further rasterization step to render.
49#[derive(Clone, Debug, MallocSizeOf)]
50pub enum Image {
51    Raster(#[conditional_malloc_size_of] Arc<RasterImage>),
52    Vector(VectorImage),
53}
54
55#[derive(Clone, Debug, Deserialize, MallocSizeOf, Serialize)]
56pub struct VectorImage {
57    pub id: VectorImageId,
58    pub svg_id: Option<Uuid>,
59    pub metadata: ImageMetadata,
60    pub cors_status: CorsStatus,
61    pub load_time: Option<CrossProcessInstant>,
62}
63
64impl Image {
65    pub fn metadata(&self) -> ImageMetadata {
66        match self {
67            Image::Vector(image, ..) => image.metadata,
68            Image::Raster(image) => image.metadata,
69        }
70    }
71
72    pub fn cors_status(&self) -> CorsStatus {
73        match self {
74            Image::Vector(image) => image.cors_status,
75            Image::Raster(image) => image.cors_status,
76        }
77    }
78
79    pub fn as_raster_image(&self) -> Option<Arc<RasterImage>> {
80        match self {
81            Image::Raster(image) => Some(image.clone()),
82            Image::Vector(..) => None,
83        }
84    }
85
86    pub fn load_time(&self) -> Option<CrossProcessInstant> {
87        match self {
88            Image::Raster(image) => image.load_time,
89            Image::Vector(image) => image.load_time,
90        }
91    }
92}
93
94/// Indicating either entire image or just metadata availability
95#[derive(Clone, Debug, MallocSizeOf)]
96pub enum ImageOrMetadataAvailable {
97    ImageAvailable { image: Image, url: ServoUrl },
98    MetadataAvailable(ImageMetadata, PendingImageId),
99}
100
101pub type ImageCacheResponseCallback = Box<dyn Fn(ImageCacheResponseMessage) + Send + 'static>;
102
103/// This is optionally passed to the image cache when requesting
104/// and image, and returned to the specified event loop when the
105/// image load completes. It is typically used to trigger a reflow
106/// and/or repaint.
107#[derive(MallocSizeOf)]
108pub struct ImageLoadListener {
109    pipeline_id: PipelineId,
110    pub id: PendingImageId,
111    #[ignore_malloc_size_of = "Difficult to measure FnOnce"]
112    callback: ImageCacheResponseCallback,
113}
114
115impl ImageLoadListener {
116    pub fn new(
117        callback: ImageCacheResponseCallback,
118        pipeline_id: PipelineId,
119        id: PendingImageId,
120    ) -> ImageLoadListener {
121        ImageLoadListener {
122            pipeline_id,
123            callback,
124            id,
125        }
126    }
127
128    pub fn respond(&self, response: ImageResponse) {
129        debug!("Notifying listener");
130        (self.callback)(ImageCacheResponseMessage::NotifyPendingImageLoadStatus(
131            PendingImageResponse {
132                pipeline_id: self.pipeline_id,
133                response,
134                id: self.id,
135            },
136        ));
137    }
138}
139
140/// The returned image.
141#[derive(Clone, Debug, MallocSizeOf)]
142pub enum ImageResponse {
143    /// The requested image was loaded.
144    Loaded(Image, ServoUrl),
145    /// The request image metadata was loaded.
146    MetadataLoaded(ImageMetadata),
147    /// The requested image failed to load or decode.
148    FailedToLoadOrDecode,
149}
150
151/// The unique id for an image that has previously been requested.
152#[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, MallocSizeOf, PartialEq, Serialize)]
153pub struct PendingImageId(pub u64);
154
155#[derive(Clone, Debug)]
156pub struct PendingImageResponse {
157    pub pipeline_id: PipelineId,
158    pub response: ImageResponse,
159    pub id: PendingImageId,
160}
161
162#[derive(Clone, Debug, Deserialize, Serialize)]
163pub struct RasterizationCompleteResponse {
164    pub pipeline_id: PipelineId,
165    pub image_id: PendingImageId,
166    pub requested_size: DeviceIntSize,
167}
168
169#[derive(Clone, Debug)]
170pub enum ImageCacheResponseMessage {
171    NotifyPendingImageLoadStatus(PendingImageResponse),
172    VectorImageRasterizationComplete(RasterizationCompleteResponse),
173}
174
175// ======================================================================
176// ImageCache public API.
177// ======================================================================
178
179pub enum ImageCacheResult {
180    Available(ImageOrMetadataAvailable),
181    FailedToLoadOrDecode,
182    Pending(PendingImageId),
183    ReadyForRequest(PendingImageId),
184}
185
186/// A shared [`ImageCacheFactory`] is a per-process data structure used to create an [`ImageCache`]
187/// inside that process in any `ScriptThread`. This allows sharing the same font database (for
188/// SVGs) and also decoding thread pool among all [`ImageCache`]s in the same process.
189pub trait ImageCacheFactory: Sync + Send {
190    fn create(
191        &self,
192        webview_id: WebViewId,
193        pipeline_id: PipelineId,
194        paint_api: &CrossProcessPaintApi,
195        font_resolver: Arc<dyn FontResolver>,
196    ) -> Arc<dyn ImageCache>;
197}
198
199/// An [`ImageCache`] manages fetching and decoding images for a single `Pipeline` for its
200/// `Document` and all of its associated `Worker`s.
201pub trait ImageCache: Sync + Send {
202    fn memory_reports(&self, prefix: &str, ops: &mut MallocSizeOfOps) -> Vec<Report>;
203
204    #[cfg(feature = "test-util")]
205    /// Returns the number of rasterization tasks
206    fn number_of_rasterize_tasks(&self) -> usize;
207
208    /// Get an [`ImageKey`] to be used for external WebRender image management for
209    /// things like canvas rendering. Returns `None` when an [`ImageKey`] cannot
210    /// be generated properly.
211    fn get_image_key(&self) -> Option<ImageKey>;
212
213    /// Definitively check whether there is a cached, fully loaded image available.
214    fn get_image(
215        &self,
216        url: ServoUrl,
217        origin: ImmutableOrigin,
218        cors_setting: Option<CorsSettings>,
219    ) -> Option<Image>;
220
221    /// Returns if the Image is already in the cache or not. If the Image is not yet completely decoded, we return [`ImageCacheResult::Pending`] or [`ImageCacheResult::Available`].
222    fn get_cached_image_status(
223        &self,
224        url: ServoUrl,
225        origin: &ImmutableOrigin,
226        cors_setting: Option<CorsSettings>,
227    ) -> ImageCacheResult;
228
229    /// Returns `Some` if the given `image_id` has already been rasterized at the given `size`.
230    /// Otherwise, triggers a new job to perform the rasterization. If a notification
231    /// is needed after rasterization is completed, the `add_rasterization_complete_listener`
232    /// API below can be used to add a listener.
233    fn rasterize_vector_image(
234        &self,
235        image_id: VectorImageId,
236        size: DeviceIntSize,
237        svg_id: Option<Uuid>,
238    ) -> Option<RasterImage>;
239
240    /// Adds a new listener to be notified once the given `image_id` has been rasterized at
241    /// the given `size`. The listener will receive a `VectorImageRasterizationComplete`
242    /// message on the given `sender`, even if the listener is called after rasterization
243    /// at has already completed.
244    fn add_rasterization_complete_listener(
245        &self,
246        pipeline_id: PipelineId,
247        image_id: VectorImageId,
248        size: DeviceIntSize,
249        callback: ImageCacheResponseCallback,
250    );
251
252    /// Removes the rasterized image from the image_cache, identified by the id of the SVG
253    fn evict_rasterized_image(&self, svg_id: &Uuid);
254
255    /// Removes the completed image from the image_cache, identified by url, origin, and cors
256    fn evict_completed_image(
257        &self,
258        url: &ServoUrl,
259        origin: &ImmutableOrigin,
260        cors_setting: &Option<CorsSettings>,
261    );
262
263    /// Synchronously get the broken image icon for this [`ImageCache`]. This will
264    /// allocate space for this icon and upload it to WebRender.
265    fn get_broken_image_icon(&self) -> Option<Arc<RasterImage>>;
266
267    /// Add a new listener for the given pending image id. If the image is already present,
268    /// the responder will still receive the expected response.
269    fn add_listener(&self, listener: ImageLoadListener);
270
271    /// Inform the image cache about a response for a pending request.
272    fn notify_pending_response(&self, id: PendingImageId, action: FetchResponseMsg);
273
274    /// Fills the image cache with a batch of keys.
275    fn dispatch_fill_key_cache_with_batch_of_keys(&self, image_keys: Vec<ImageKey>);
276
277    /// Clear the image cache.
278    fn clear(&self);
279}
net_traits/image_cache.rs

net_traits/
image_cache.rs
