Add pre-fetching on hover with a small segment data cache

4 files changed, 158 insertions, 56 deletions

diff --git a/src/content.ts b/src/content.ts
index c8cd4879..398102aa 100644
--- a/src/content.ts
+++ b/src/content.ts
@@ -1,7 +1,6 @@
 import Config from "./config";
 import {
     ActionType,
-    ActionTypes,
     Category,
     CategorySkipOption,
     ChannelIDInfo,
@@ -18,7 +17,6 @@ import {
     VideoInfo,
 } from "./types";
 import Utils from "./utils";
-import * as CompileConfig from "../config.json";
 import PreviewBar, { PreviewBarSegment } from "./js-components/previewBar";
 import SkipNotice from "./render/SkipNotice";
 import SkipNoticeComponent from "./components/SkipNoticeComponent";
@@ -52,6 +50,7 @@ import { asyncRequestToServer } from "./utils/requests";
 import { isMobileControlsOpen } from "./utils/mobileUtils";
 import { defaultPreviewTime } from "./utils/constants";
 import { onVideoPage } from "../maze-utils/src/pageInfo";
+import { getSegmentsForVideo } from "./utils/segmentData";
 
 cleanPage();
 
@@ -269,7 +268,7 @@ function messageListener(request: Message, sender: unknown, sendResponse: (respo
             sendResponse({ hasVideo: getVideoID() != null });
             // fetch segments
             if (getVideoID()) {
-                sponsorsLookup(false);
+                sponsorsLookup(false, true);
             }
 
             break;
@@ -364,7 +363,7 @@ function contentConfigUpdateListener(changes: StorageChangesObject) {
                 updateVisibilityOfPlayerControlsButton()
                 break;
             case "categorySelections":
-                sponsorsLookup();
+                sponsorsLookup(true, true);
                 break;
             case "barTypes":
                 setCategoryColorCSSVariables();
@@ -1133,42 +1132,20 @@ function setupCategoryPill() {
     categoryPill.attachToPage(isOnMobileYouTube(), isOnInvidious(), voteAsync);
 }
 
-async function sponsorsLookup(keepOldSubmissions = true) {
-    const categories: string[] = Config.config.categorySelections.map((category) => category.name);
-
-    const extraRequestData: Record<string, unknown> = {};
-    const hashParams = getHashParams();
-    if (hashParams.requiredSegment) extraRequestData.requiredSegment = hashParams.requiredSegment;
-
+async function sponsorsLookup(keepOldSubmissions = true, ignoreCache = false) {
     const videoID = getVideoID()
     if (!videoID) {
         console.error("[SponsorBlock] Attempted to fetch segments with a null/undefined videoID.");
         return;
     }
-    const hashPrefix = (await getHash(videoID, 1)).slice(0, 4) as VideoID & HashedValue;
-    const response = await asyncRequestToServer('GET', "/api/skipSegments/" + hashPrefix, {
-        categories: CompileConfig.categoryList,
-        actionTypes: ActionTypes,
-        ...extraRequestData
-    }, {
-        "X-CLIENT-NAME": `${chrome.runtime.id}/v${chrome.runtime.getManifest().version}`
-    });
+
+    const segmentData = await getSegmentsForVideo(videoID, ignoreCache);
 
     // store last response status
-    lastResponseStatus = response?.status;
-
-    if (response?.ok) {
-        const enabledActionTypes = getEnabledActionTypes();
-
-        const receivedSegments: SponsorTime[] = JSON.parse(response.responseText)
-                    ?.filter((video) => video.videoID === getVideoID())
-                    ?.map((video) => video.segments)?.[0]
-                    ?.filter((segment) => enabledActionTypes.includes(segment.actionType) && categories.includes(segment.category))
-                    ?.map((segment) => ({
-                        ...segment,
-                        source: SponsorSourceType.Server
-                    }))
-                    ?.sort((a, b) => a.segment[0] - b.segment[0]);
+    lastResponseStatus = segmentData.status;
+    if (segmentData.status === 200) {
+        const receivedSegments = segmentData.segments;
+
         if (receivedSegments && receivedSegments.length) {
             sponsorDataFound = true;
 
@@ -1208,6 +1185,7 @@ async function sponsorsLookup(keepOldSubmissions = true) {
             }
 
             // See if some segments should be hidden
+            const hashPrefix = (await getHash(videoID, 1)).slice(0, 4) as VideoID & HashedValue;
             const downvotedData = Config.local.downvotedSegments[hashPrefix];
             if (downvotedData) {
                 for (const segment of sponsorTimes) {
@@ -1280,18 +1258,6 @@ function importExistingChapters(wait: boolean) {
     }
 }
 
-function getEnabledActionTypes(forceFullVideo = false): ActionType[] {
-    const actionTypes = [ActionType.Skip, ActionType.Poi, ActionType.Chapter];
-    if (Config.config.muteSegments) {
-        actionTypes.push(ActionType.Mute);
-    }
-    if (Config.config.fullVideoSegments || forceFullVideo) {
-        actionTypes.push(ActionType.Full);
-    }
-
-    return actionTypes;
-}
-
 async function lockedCategoriesLookup(): Promise<void> {
     const hashPrefix = (await getHash(getVideoID(), 1)).slice(0, 4);
     const response = await asyncRequestToServer("GET", "/api/lockCategories/" + hashPrefix);
@@ -2016,7 +1982,7 @@ function startOrEndTimingNewSegment() {
     Config.forceLocalUpdate("unsubmittedSegments");
 
     // Make sure they know if someone has already submitted something it while they were watching
-    sponsorsLookup();
+    sponsorsLookup(true, true);
 
     updateEditButtonsOnPlayer();
     updateSponsorTimesSubmitting(false);
diff --git a/src/utils/requests.ts b/src/utils/requests.ts
index acbde374..8ce80601 100644
--- a/src/utils/requests.ts
+++ b/src/utils/requests.ts
@@ -23,8 +23,6 @@ export function asyncRequestToCustomServer(type: string, url: string, data = {},
 export async function asyncRequestToServer(type: string, address: string, data = {}, headers = {}): Promise<FetchResponse> {
     const serverAddress = Config.config.testingServer ? CompileConfig.testingServerAddress : Config.config.serverAddress;
 
-    console.log(address, headers)
-
     return await (asyncRequestToCustomServer(type, serverAddress + address, data, headers));
 }
 
diff --git a/src/utils/segmentData.ts b/src/utils/segmentData.ts
new file mode 100644
index 00000000..1c2e631a
--- /dev/null
+++ b/src/utils/segmentData.ts
@@ -0,0 +1,104 @@
+import { DataCache } from "../../maze-utils/src/cache";
+import { getHash, HashedValue } from "../../maze-utils/src/hash";
+import Config from "../config";
+import * as CompileConfig from "../../config.json";
+import { ActionType, ActionTypes, SponsorSourceType, SponsorTime, VideoID } from "../types";
+import { getHashParams } from "./pageUtils";
+import { asyncRequestToServer } from "./requests";
+
+const segmentDataCache = new DataCache<VideoID, SegmentResponse>(() => {
+    return {
+        segments: null,
+        status: 200
+    };
+}, 5);
+
+const pendingList: Record<VideoID, Promise<SegmentResponse>> = {};
+
+export interface SegmentResponse {
+    segments: SponsorTime[] | null;
+    status: number;
+}
+
+export async function getSegmentsForVideo(videoID: VideoID, ignoreCache: boolean): Promise<SegmentResponse> {
+    if (!ignoreCache) {
+        const cachedData = segmentDataCache.getFromCache(videoID);
+        if (cachedData) {
+            segmentDataCache.cacheUsed(videoID);
+            return cachedData;
+        }
+    }
+
+    if (pendingList[videoID]) {
+        return await pendingList[videoID];
+    }
+
+    const pendingData = fetchSegmentsForVideo(videoID);
+    pendingList[videoID] = pendingData;
+
+    const result = await pendingData;
+    delete pendingList[videoID];
+
+    return result;
+}
+
+async function fetchSegmentsForVideo(videoID: VideoID): Promise<SegmentResponse> {
+    const categories: string[] = Config.config.categorySelections.map((category) => category.name);
+
+    const extraRequestData: Record<string, unknown> = {};
+    const hashParams = getHashParams();
+    if (hashParams.requiredSegment) extraRequestData.requiredSegment = hashParams.requiredSegment;
+    
+    const hashPrefix = (await getHash(videoID, 1)).slice(0, 4) as VideoID & HashedValue;
+    const response = await asyncRequestToServer('GET', "/api/skipSegments/" + hashPrefix, {
+        categories: CompileConfig.categoryList,
+        actionTypes: ActionTypes,
+        ...extraRequestData
+    }, {
+        "X-CLIENT-NAME": `${chrome.runtime.id}/v${chrome.runtime.getManifest().version}`
+    });
+
+    if (response.ok) {
+        const enabledActionTypes = getEnabledActionTypes();
+
+        const receivedSegments: SponsorTime[] = JSON.parse(response.responseText)
+                    ?.filter((video) => video.videoID === videoID)
+                    ?.map((video) => video.segments)?.[0]
+                    ?.filter((segment) => enabledActionTypes.includes(segment.actionType) && categories.includes(segment.category))
+                    ?.map((segment) => ({
+                        ...segment,
+                        source: SponsorSourceType.Server
+                    }))
+                    ?.sort((a, b) => a.segment[0] - b.segment[0]);
+
+        if (receivedSegments && receivedSegments.length) {
+            const result = {
+                segments: receivedSegments,
+                status: response.status
+            };
+
+            segmentDataCache.setupCache(videoID).segments = result.segments;
+            return result;
+        } else {
+            // Setup with null data
+            segmentDataCache.setupCache(videoID);
+        }
+    }
+
+    return {
+        segments: null,
+        status: response.status
+    };
+}
+
+function getEnabledActionTypes(forceFullVideo = false): ActionType[] {
+    const actionTypes = [ActionType.Skip, ActionType.Poi, ActionType.Chapter];
+    if (Config.config.muteSegments) {
+        actionTypes.push(ActionType.Mute);
+    }
+    if (Config.config.fullVideoSegments || forceFullVideo) {
+        actionTypes.push(ActionType.Full);
+    }
+
+    return actionTypes;
+}
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diff --git a/src/utils/thumbnails.ts b/src/utils/thumbnails.ts
index 61d28f18..0fb2579e 100644
--- a/src/utils/thumbnails.ts
+++ b/src/utils/thumbnails.ts
@@ -1,10 +1,15 @@
 import { isOnInvidious, parseYouTubeVideoIDFromURL } from "../../maze-utils/src/video";
 import Config from "../config";
 import { getVideoLabel } from "./videoLabels";
-import { setThumbnailListener } from "../../maze-utils/src/thumbnailManagement";
-
-export async function labelThumbnails(thumbnails: HTMLImageElement[]): Promise<void> {
-    await Promise.all(thumbnails.map((t) => labelThumbnail(t)));
+import { getThumbnailSelector, setThumbnailListener } from "../../maze-utils/src/thumbnailManagement";
+import { VideoID } from "../types";
+import { getSegmentsForVideo } from "./segmentData";
+
+export async function handleThumbnails(thumbnails: HTMLImageElement[]): Promise<void> {
+    await Promise.all(thumbnails.map((t) => {
+        labelThumbnail(t);
+        setupThumbnailHover(t);
+    }));
 }
 
 export async function labelThumbnail(thumbnail: HTMLImageElement): Promise<HTMLElement | null> {
@@ -13,9 +18,7 @@ export async function labelThumbnail(thumbnail: HTMLImageElement): Promise<HTMLE
         return null;
     }
     
-    const link = (isOnInvidious() ? thumbnail.parentElement : thumbnail.querySelector("#thumbnail")) as HTMLAnchorElement
-    if (!link || link.nodeName !== "A" || !link.href) return null; // no link found
-    const videoID = parseYouTubeVideoIDFromURL(link.href)?.videoID;
+    const videoID = extractVideoID(thumbnail);
     if (!videoID) {
         hideThumbnailLabel(thumbnail);
         return null;
@@ -37,6 +40,37 @@ export async function labelThumbnail(thumbnail: HTMLImageElement): Promise<HTMLE
     return overlay;
 }
 
+export async function setupThumbnailHover(thumbnail: HTMLImageElement): Promise<void> {
+    // Cache would be reset every load due to no SPA
+    if (isOnInvidious()) return;
+
+    const mainElement = thumbnail.closest("#dismissible") as HTMLElement;
+    if (mainElement) {
+        mainElement.removeEventListener("mouseenter", thumbnailHoverListener);
+        mainElement.addEventListener("mouseenter", thumbnailHoverListener);
+    }
+}
+
+function thumbnailHoverListener(e: MouseEvent) {
+    if (!chrome.runtime?.id) return;
+
+    const thumbnail = (e.target as HTMLElement).querySelector(getThumbnailSelector()) as HTMLImageElement;
+    if (!thumbnail) return;
+
+    // Pre-fetch data for this video
+    const videoID = extractVideoID(thumbnail);
+    if (videoID) {
+        void getSegmentsForVideo(videoID, false);
+    }
+}
+
+function extractVideoID(thumbnail: HTMLImageElement): VideoID | null {
+    const link = (isOnInvidious() ? thumbnail.parentElement : thumbnail.querySelector("#thumbnail")) as HTMLAnchorElement
+    if (!link || link.nodeName !== "A" || !link.href) return null; // no link found
+
+    return parseYouTubeVideoIDFromURL(link.href)?.videoID;
+}
+
 function getOldThumbnailLabel(thumbnail: HTMLImageElement): HTMLElement | null {
     return thumbnail.querySelector(".sponsorThumbnailLabel") as HTMLElement | null;
 }   
@@ -109,7 +143,7 @@ function insertSBIconDefinition() {
 }
 
 export function setupThumbnailListener(): void {
-    setThumbnailListener(labelThumbnails, () => {
+    setThumbnailListener(handleThumbnails, () => {
         insertSBIconDefinition();
     }, () => Config.isReady());
 }
\ No newline at end of file