jocmp · jocmp · Mar 29, 2026 · Mar 29, 2026 · Apr 8, 2026
diff --git a/CLAUDE.md b/CLAUDE.md
@@ -29,5 +29,5 @@ Capy Reader is an RSS reader for Android split into several gradle modules
 - When naming accessors, prefer "savedSearches" over `getSavedSearches` unless there's a parameter, in which case use "get"
 - Prefer explicit named parameters when passing arguments to Jetpack Compose functions over positional arguments.
 - JavaScript files are written using JSDoc to ensure typechecking without the overhead of TypeScript.
+- Where possible, prefer functional iteration (map, forEach) as opposed to for-loops
 - Prefer `orEmpty()` instead of `?: ""`
-- Prefer functional iteration (map, forEach) as opposed to for-loops
diff --git a/app/src/main/java/com/capyreader/app/ui/articles/AccountBuildArticlePagerExt.kt b/app/src/main/java/com/capyreader/app/ui/articles/AccountBuildArticlePagerExt.kt
@@ -13,11 +13,12 @@ fun Account.buildArticlePager(
     query: String? = null,
     sortOrder: SortOrder = SortOrder.NEWEST_FIRST,
     since: OffsetDateTime = OffsetDateTime.now()
-): Pager<Int, Article> {
+): Pager<Long, Article> {
     return Pager(
         config = PagingConfig(
             pageSize = 100,
             prefetchDistance = 10,
+            initialLoadSize = 50,
         ),
         pagingSourceFactory = {
             ArticlePagerFactory(database).findArticles(

diff --git a/app/src/main/java/com/capyreader/app/ui/articles/ArticlePagerFactory.kt b/app/src/main/java/com/capyreader/app/ui/articles/ArticlePagerFactory.kt
@@ -19,7 +19,7 @@ class ArticlePagerFactory(private val database: Database) {
         query: String?,
         sortOrder: SortOrder,
         since: OffsetDateTime
-    ): PagingSource<Int, Article> {
+    ): PagingSource<Long, Article> {
         return when (filter) {
             is ArticleFilter.Articles -> articleSource(filter, query, sortOrder, since)
             is ArticleFilter.Feeds -> feedSource(filter, query, sortOrder, since)
@@ -35,25 +35,21 @@ class ArticlePagerFactory(private val database: Database) {
         query: String?,
         sortOrder: SortOrder,
         since: OffsetDateTime
-    ): PagingSource<Int, Article> {
+    ): PagingSource<Long, Article> {
         return QueryPagingSource(
-            countQuery = articles.byStatus.count(
+            transacter = database.articlesQueries,
+            context = Dispatchers.IO,
+            pageBoundariesProvider = articles.byStatus.pageBoundaries(
                 status = filter.status,
                 query = query,
-                since = since
+                since = since,
+            ),
+            queryProvider = articles.byStatus.keyed(
+                status = filter.status,
+                query = query,
+                sortOrder = sortOrder,
+                since = since,
             ),
-            transacter = database.articlesQueries,
-            context = Dispatchers.IO,
-            queryProvider = { limit, offset ->
-                articles.byStatus.all(
-                    status = filter.status,
-                    query = query,
-                    since = since,
-                    limit = limit,
-                    sortOrder = sortOrder,
-                    offset = offset,
-                )
-            }
         )
     }
 
@@ -62,7 +58,7 @@ class ArticlePagerFactory(private val database: Database) {
         query: String?,
         sortOrder: SortOrder,
         since: OffsetDateTime,
-    ): PagingSource<Int, Article> {
+    ): PagingSource<Long, Article> {
         val feedIDs = listOf(filter.feedID)
 
         return feedsSource(
@@ -80,7 +76,7 @@ class ArticlePagerFactory(private val database: Database) {
         query: String?,
         sortOrder: SortOrder,
         since: OffsetDateTime
-    ): PagingSource<Int, Article> {
+    ): PagingSource<Long, Article> {
         val feedIDs = database
             .taggingsQueries
             .findFeedIDs(folderTitle = filter.folderTitle)
@@ -103,29 +99,25 @@ class ArticlePagerFactory(private val database: Database) {
         sortOrder: SortOrder,
         priority: FeedPriority,
         since: OffsetDateTime
-    ): PagingSource<Int, Article> {
+    ): PagingSource<Long, Article> {
         return QueryPagingSource(
-            countQuery = articles.byFeed.count(
+            transacter = database.articlesQueries,
+            context = Dispatchers.IO,
+            pageBoundariesProvider = articles.byFeed.pageBoundaries(
                 feedIDs = feedIDs,
                 status = filter.status,
                 query = query,
                 since = since,
                 priority = priority,
             ),
-            transacter = database.articlesQueries,
-            context = Dispatchers.IO,
-            queryProvider = { limit, offset ->
-                articles.byFeed.all(
-                    feedIDs = feedIDs,
-                    status = filter.status,
-                    query = query,
-                    since = since,
-                    limit = limit,
-                    sortOrder = sortOrder,
-                    offset = offset,
-                    priority = priority,
-                )
-            }
+            queryProvider = articles.byFeed.keyed(
+                feedIDs = feedIDs,
+                status = filter.status,
+                query = query,
+                sortOrder = sortOrder,
+                since = since,
+                priority = priority,
+            ),
         )
     }
 
@@ -134,27 +126,23 @@ class ArticlePagerFactory(private val database: Database) {
         query: String?,
         sortOrder: SortOrder,
         since: OffsetDateTime
-    ): PagingSource<Int, Article> {
+    ): PagingSource<Long, Article> {
         return QueryPagingSource(
-            countQuery = articles.bySavedSearch.count(
+            transacter = database.articlesQueries,
+            context = Dispatchers.IO,
+            pageBoundariesProvider = articles.bySavedSearch.pageBoundaries(
                 savedSearchID = filter.savedSearchID,
                 status = filter.status,
                 query = query,
-                since = since
+                since = since,
+            ),
+            queryProvider = articles.bySavedSearch.keyed(
+                savedSearchID = filter.savedSearchID,
+                status = filter.status,
+                query = query,
+                sortOrder = sortOrder,
+                since = since,
             ),
-            transacter = database.articlesQueries,
-            context = Dispatchers.IO,
-            queryProvider = { limit, offset ->
-                articles.bySavedSearch.all(
-                    savedSearchID = filter.savedSearchID,
-                    status = filter.status,
-                    query = query,
-                    since = since,
-                    limit = limit,
-                    sortOrder = sortOrder,
-                    offset = offset,
-                )
-            }
         )
     }
 
@@ -189,25 +177,21 @@ class ArticlePagerFactory(private val database: Database) {
         query: String?,
         sortOrder: SortOrder,
         since: OffsetDateTime
-    ): PagingSource<Int, Article> {
+    ): PagingSource<Long, Article> {
         return QueryPagingSource(
-            countQuery = articles.byToday.count(
+            transacter = database.articlesQueries,
+            context = Dispatchers.IO,
+            pageBoundariesProvider = articles.byToday.pageBoundaries(
                 status = filter.status,
                 query = query,
-                since = since
+                since = since,
+            ),
+            queryProvider = articles.byToday.keyed(
+                status = filter.status,
+                query = query,
+                sortOrder = sortOrder,
+                since = since,
             ),
-            transacter = database.articlesQueries,
-            context = Dispatchers.IO,
-            queryProvider = { limit, offset ->
-                articles.byToday.all(
-                    status = filter.status,
-                    query = query,
-                    limit = limit,
-                    sortOrder = sortOrder,
-                    offset = offset,
-                    since = since,
-                )
-            }
         )
     }
 }
diff --git a/bench/src/main/kotlin/com/jocmp/bench/Commands.kt b/bench/src/main/kotlin/com/jocmp/bench/Commands.kt
@@ -89,30 +89,34 @@ suspend fun commandSelectProfile(account: Account) {
 
     val total = account.countAllByStatus(ArticleStatus.ALL).first()
 
+    val boundariesProvider = records.byStatus.pageBoundaries(
+        status = ArticleStatus.ALL,
+    )
+    val queryProvider = records.byStatus.keyed(
+        status = ArticleStatus.ALL,
+        sortOrder = SortOrder.NEWEST_FIRST,
+    )
+
     val (pageCount, pageDuration) = measureTimedValue {
-        var offset = 0L
+        val boundaries = boundariesProvider(null, pageSize).executeAsList()
         var pages = 0
 
-        while (offset < total) {
-            records.byStatus.all(
-                status = ArticleStatus.ALL,
-                limit = pageSize,
-                offset = offset,
-                sortOrder = SortOrder.NEWEST_FIRST,
-            ).executeAsList()
-            offset += pageSize
+        for (i in boundaries.indices) {
+            val begin = boundaries[i]
+            val end = boundaries.getOrNull(i + 1)
+            queryProvider(begin, end).executeAsList()
             pages++
         }
 
         pages
     }
 
-    val firstArticleID = records.byStatus.all(
-        status = ArticleStatus.ALL,
-        limit = 1,
-        offset = 0,
-        sortOrder = SortOrder.NEWEST_FIRST,
-    ).executeAsOneOrNull()?.id
+    val firstPage = boundariesProvider(null, 1).executeAsList()
+    val firstArticleID = if (firstPage.isNotEmpty()) {
+        queryProvider(firstPage.first(), null).executeAsList().firstOrNull()?.id
+    } else {
+        null
+    }
 
     val (_, findDuration) = measureTimedValue {
         if (firstArticleID != null) {

diff --git a/capy/src/main/java/com/jocmp/capy/AccountLatestArticlesExt.kt b/capy/src/main/java/com/jocmp/capy/AccountLatestArticlesExt.kt
@@ -7,16 +7,22 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.Flow
 
 fun Account.latestArticles(limit: Long = 30): Flow<List<Article>> {
-    return articleRecords
+    val boundariesProvider = articleRecords
         .byStatus
-        .all(
+        .pageBoundaries(status = ArticleStatus.UNREAD)
+
+    val queryProvider = articleRecords
+        .byStatus
+        .keyed(
             status = ArticleStatus.UNREAD,
-            query = null,
-            since = null,
-            limit = limit,
             sortOrder = SortOrder.NEWEST_FIRST,
-            offset = 0,
         )
+
+    val boundaries = boundariesProvider(null, limit).executeAsList()
+    val begin = boundaries.firstOrNull() ?: return kotlinx.coroutines.flow.flowOf(emptyList())
+    val end = boundaries.getOrNull(1)
+
+    return queryProvider(begin, end)
         .asFlow()
         .mapToList(Dispatchers.IO)
 }
diff --git a/capy/src/main/java/com/jocmp/capy/persistence/articles/ByArticleStatus.kt b/capy/src/main/java/com/jocmp/capy/persistence/articles/ByArticleStatus.kt
@@ -72,6 +72,68 @@ class ByArticleStatus(private val database: Database) {
         return database.articlesQueries.lastUpdatedAt().executeAsOne().MAX
     }
 
+    fun pageBoundaries(
+        status: ArticleStatus,
+        query: String? = null,
+        since: OffsetDateTime? = null,
+    ): (anchor: Long?, limit: Long) -> Query<Long> {
+        val (read, starred) = status.toStatusPair
+
+        return { anchor, limit ->
+            database.articlesByStatusQueries.pageBoundaries(
+                read = read,
+                starred = starred,
+                lastReadAt = mapLastRead(read, since),
+                lastUnstarredAt = mapLastUnstarred(starred, since),
+                publishedSince = null,
+                query = query,
+                anchor = anchor,
+                limit = limit,
+                mapper = { publishedAt -> publishedAt ?: 0L }
+            )
+        }
+    }
+
+    fun keyed(
+        status: ArticleStatus,
+        query: String? = null,
+        sortOrder: SortOrder,
+        since: OffsetDateTime? = null,
+    ): (beginInclusive: Long, endExclusive: Long?) -> Query<Article> {
+        val (read, starred) = status.toStatusPair
+        val queries = database.articlesByStatusQueries
+
+        return if (isNewestFirst(sortOrder)) {
+            { begin, end ->
+                queries.keyedNewestFirst(
+                    read = read,
+                    starred = starred,
+                    lastReadAt = mapLastRead(read, since),
+                    lastUnstarredAt = mapLastUnstarred(starred, since),
+                    publishedSince = null,
+                    query = query,
+                    beginInclusive = begin,
+                    endExclusive = end,
+                    mapper = ::listMapper,
+                )
+            }
+        } else {
+            { begin, end ->
+                queries.keyedOldestFirst(
+                    read = read,
+                    starred = starred,
+                    lastReadAt = mapLastRead(read, since),
+                    lastUnstarredAt = mapLastUnstarred(starred, since),
+                    publishedSince = null,
+                    query = query,
+                    beginInclusive = begin,
+                    endExclusive = end,
+                    mapper = ::listMapper,
+                )
+            }
+        }
+    }
+
     fun count(
         status: ArticleStatus,
         query: String? = null,