From 1dc90519a76292138c346a5622ac5571713fc030 Mon Sep 17 00:00:00 2001
From: Govinda Wasserman <gwasserman@google.com>
Date: Wed, 22 May 2024 09:41:34 -0400
Subject: Preload full set of preview image metadata pages

This is the first step in mitigating the bottleneck of slow metadata
loading by proactively loading pages to the max window size.

Test: atest CursorPreviewsInteractorTest FetchPreviewsInteractorTest
Test: manual test using ShareTest with high metadata latency
BUG: 341923886
Flag: android.service.chooser.chooser_payload_toggling
Change-Id: I1192e7bdf7db77573990745dd5b05d7ef86d7f20
---
 .../domain/interactor/CursorPreviewsInteractor.kt  | 36 ++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

(limited to 'java/src')

diff --git a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/domain/interactor/CursorPreviewsInteractor.kt b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/domain/interactor/CursorPreviewsInteractor.kt
index 97b087e1..f02834e0 100644
--- a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/domain/interactor/CursorPreviewsInteractor.kt
+++ b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/domain/interactor/CursorPreviewsInteractor.kt
@@ -76,10 +76,42 @@ constructor(
                 .toMap(ConcurrentHashMap())
         val pagedCursor: PagedCursor<CursorRow?> = uriCursor.paged(pageSize)
         val startPosition = uriCursor.extras?.getInt(POSITION, 0) ?: 0
-        val state = readInitialState(pagedCursor, startPosition, unclaimedRecords)
+        val state =
+            loadToMaxPages(
+                initialState = readInitialState(pagedCursor, startPosition, unclaimedRecords),
+                pagedCursor = pagedCursor,
+                unclaimedRecords = unclaimedRecords,
+            )
         processLoadRequests(state, pagedCursor, unclaimedRecords)
     }
 
+    private suspend fun loadToMaxPages(
+        initialState: CursorWindow,
+        pagedCursor: PagedCursor<CursorRow?>,
+        unclaimedRecords: MutableUnclaimedMap,
+    ): CursorWindow {
+        var state = initialState
+        val startPageNum = state.firstLoadedPageNum
+        while ((state.hasMoreLeft || state.hasMoreRight) && state.numLoadedPages < maxLoadedPages) {
+            interactor.setPreviews(
+                previewsByKey = state.merged.values.toSet(),
+                startIndex = startPageNum,
+                hasMoreLeft = state.hasMoreLeft,
+                hasMoreRight = state.hasMoreRight,
+            )
+            val loadedLeft = startPageNum - state.firstLoadedPageNum
+            val loadedRight = state.lastLoadedPageNum - startPageNum
+            state =
+                when {
+                    state.hasMoreLeft && loadedLeft < loadedRight ->
+                        state.loadMoreLeft(pagedCursor, unclaimedRecords)
+                    state.hasMoreRight -> state.loadMoreRight(pagedCursor, unclaimedRecords)
+                    else -> state.loadMoreLeft(pagedCursor, unclaimedRecords)
+                }
+        }
+        return state
+    }
+
     /** Loop forever, processing any loading requests from the UI and updating local cache. */
     private suspend fun processLoadRequests(
         initialState: CursorWindow,
@@ -301,5 +333,5 @@ annotation class MaxLoadedPages
 object ShareouselConstants {
     @Provides @PageSize fun pageSize(): Int = 16
 
-    @Provides @MaxLoadedPages fun maxLoadedPages(): Int = 3
+    @Provides @MaxLoadedPages fun maxLoadedPages(): Int = 8
 }
-- 
cgit v1.2.3-59-g8ed1b