faster rescanning

modules/astra-library-scanner/android/src/androidTest/java/expo/modules/astralibraryscanner/data/LocalScanFastPathTest.kt

@@ -0,0 +1,148 @@
+package expo.modules.astralibraryscanner.data
+
+import android.content.Context
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.filters.LargeTest
+import java.util.concurrent.atomic.AtomicInteger
+import kotlinx.coroutines.runBlocking
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@LargeTest
+@RunWith(AndroidJUnit4::class)
+class LocalScanFastPathTest {
+  @Test
+  fun unchangedIncrementalScanKeepsRevisionWhileChangesAndFullScansPublish() = runBlocking {
+    val context = ApplicationProvider.getApplicationContext<Context>()
+    val repository = AstraLibraryRepository.get(context)
+    val suffix = System.nanoTime().toString()
+    val treeUri =
+      "content://com.android.externalstorage.documents/tree/primary%3AMusic%2Fscan-$suffix"
+    val parentUri =
+      "$treeUri/document/primary%3AMusic%2Fscan-$suffix"
+    val trackUri = "$parentUri%2Fsong.flac"
+    val otherTrackUri = "$parentUri%2Fother.flac"
+    val folder = repository.registerFolder(treeUri, "Fast scan test")
+    val folderId = (folder.getValue("id") as Number).toLong()
+    val extractionCount = AtomicInteger()
+    val catalogEventCount = AtomicInteger()
+    val catalogListener: (Long) -> Unit = { catalogEventCount.incrementAndGet() }
+    var files = listOf(
+      file(trackUri, parentUri, size = 1_024, mtime = 10),
+      file(otherTrackUri, parentUri, size = 2_048, mtime = 20),
+    )
+
+    repository.addCatalogListener(catalogListener)
+    try {
+      val initial = repository.scanLocalFolder(
+        folderId = folderId,
+        full = false,
+        discover = { files },
+        extract = {
+          extractionCount.incrementAndGet()
+          metadata("Initial title")
+        },
+        onProgress = { _, _, _, _ -> },
+      )
+      assertEquals(2, initial.added)
+      assertEquals(2, extractionCount.get())
+      assertEquals(1, catalogEventCount.get())
+
+      catalogEventCount.set(0)
+      val unchanged = repository.scanLocalFolder(
+        folderId = folderId,
+        full = false,
+        discover = { files.reversed() },
+        extract = {
+          extractionCount.incrementAndGet()
+          metadata("Should not be extracted")
+        },
+        onProgress = { _, _, _, _ -> },
+      )
+      assertEquals(initial.revision, unchanged.revision)
+      assertEquals(0, unchanged.added)
+      assertEquals(0, unchanged.updated)
+      assertEquals(0, unchanged.removed)
+      assertEquals(2, unchanged.total)
+      assertEquals(2, extractionCount.get())
+      assertEquals(0, catalogEventCount.get())
+      assertNotNull(repository.getTrack(trackUri))
+      val readyFolder = repository.listFolders()
+        .single { (it.getValue("id") as Number).toLong() == folderId }
+      assertEquals("ready", readyFolder["scan_status"])
+      assertNotNull(readyFolder["last_scanned_at"])
+
+      files = files.map { discovered ->
+        if (discovered.uri == trackUri) discovered.copy(lastModified = 11) else discovered
+      }
+      catalogEventCount.set(0)
+      val changed = repository.scanLocalFolder(
+        folderId = folderId,
+        full = false,
+        discover = { files },
+        extract = {
+          extractionCount.incrementAndGet()
+          metadata("Changed title")
+        },
+        onProgress = { _, _, _, _ -> },
+      )
+      assertNotEquals(unchanged.revision, changed.revision)
+      assertEquals(0, changed.added)
+      assertEquals(1, changed.updated)
+      assertEquals(3, extractionCount.get())
+      assertEquals(1, catalogEventCount.get())
+
+      catalogEventCount.set(0)
+      val rebuilt = repository.scanLocalFolder(
+        folderId = folderId,
+        full = true,
+        discover = { files },
+        extract = {
+          extractionCount.incrementAndGet()
+          metadata("Rebuilt title")
+        },
+        onProgress = { _, _, _, _ -> },
+      )
+      assertNotEquals(changed.revision, rebuilt.revision)
+      assertEquals(2, rebuilt.updated)
+      assertEquals(5, extractionCount.get())
+      assertEquals(1, catalogEventCount.get())
+      assertEquals("Rebuilt title", repository.getTrack(trackUri)?.get("title"))
+    } finally {
+      repository.removeCatalogListener(catalogListener)
+      repository.removeFolder(folderId)
+    }
+  }
+
+  private fun file(
+    uri: String,
+    parentUri: String,
+    size: Long?,
+    mtime: Long,
+  ): LocalAudioFile = LocalAudioFile(
+    uri = uri,
+    name = "song.flac",
+    size = size,
+    lastModified = mtime,
+    mimeType = "audio/flac",
+    parentUri = parentUri,
+    coverUri = null,
+  )
+
+  private fun metadata(title: String): LocalAudioMetadata = LocalAudioMetadata(
+    ok = true,
+    title = title,
+    artist = "Artist",
+    album = "Album",
+    mimeType = "audio/flac",
+    durationMs = 180_000,
+    sampleRate = 44_100,
+    channels = 2,
+    bitsPerSample = 16,
+    codecMime = "audio/flac",
+  )
+}

modules/astra-library-scanner/android/src/main/java/expo/modules/astralibraryscanner/data/AstraLibraryRepository.kt

@@ -1,10 +1,13 @@
 package expo.modules.astralibraryscanner.data
 
 import android.content.Context
+import android.content.pm.ApplicationInfo
 import android.database.sqlite.SQLiteDatabaseCorruptException
 import android.database.sqlite.SQLiteException
 import android.os.Build
+import android.os.SystemClock
 import android.os.Trace
+import android.util.Log
 import androidx.room.Room
 import androidx.room.RoomDatabase
 import expo.modules.astralibraryscanner.queue.QueueReorder
@@ -44,6 +47,51 @@ internal const val PLAYBACK_WINDOW_SIZE =
   PLAYBACK_HISTORY_WINDOW + 1 + PLAYBACK_UPCOMING_WINDOW
 private val traceCookie = AtomicInteger()
 
+private const val SCAN_LOG_TAG = "AstraLibraryScan"
+
+private class LocalScanTiming(
+  private val folderId: Long,
+) {
+  private val totalStartedNanos = SystemClock.elapsedRealtimeNanos()
+  private var lockStartedNanos = totalStartedNanos
+
+  var lockWaitMs: Long = 0
+  var discoveryMs: Long = 0
+  var comparisonMs: Long = 0
+  var extractionAndStagingMs: Long = 0
+  var readModelMs: Long = 0
+  var publishMs: Long = 0
+  var files: Int = 0
+  var outcome: String = "failed"
+
+  fun beginLockWait() {
+    lockStartedNanos = SystemClock.elapsedRealtimeNanos()
+  }
+
+  fun acquiredLock() {
+    lockWaitMs = elapsedMs(lockStartedNanos)
+  }
+
+  fun now(): Long = SystemClock.elapsedRealtimeNanos()
+
+  fun elapsedMs(startedNanos: Long): Long =
+    (SystemClock.elapsedRealtimeNanos() - startedNanos) / 1_000_000L
+
+  fun logIfDebuggable(context: Context) {
+    val debuggable =
+      context.applicationInfo.flags and ApplicationInfo.FLAG_DEBUGGABLE != 0
+    if (!debuggable) return
+    Log.d(
+      SCAN_LOG_TAG,
+      "folderId=$folderId outcome=$outcome files=$files" +
+        " lockWaitMs=$lockWaitMs discoveryMs=$discoveryMs" +
+        " comparisonMs=$comparisonMs extractionAndStagingMs=$extractionAndStagingMs" +
+        " readModelMs=$readModelMs publishMs=$publishMs" +
+        " totalMs=${elapsedMs(totalStartedNanos)}",
+    )
+  }
+}
+
 private suspend fun <T> traceAsyncSection(
   name: String,
   block: suspend () -> T,
@@ -70,6 +118,35 @@ private fun throwIfScanCancelled(isCancelled: () -> Boolean) {
   if (isCancelled()) throw ScanCancelledException()
 }
 
+internal fun canReuseActiveLocalGeneration(
+  full: Boolean,
+  previousSource: CatalogSourceEntity?,
+  files: List<LocalAudioFile>,
+  existingByPath: Map<String, TrackEntity>,
+): Boolean {
+  if (
+    full ||
+    previousSource?.activeGenerationId == null ||
+    previousSource.artistCreditVersion < CURRENT_ARTIST_CREDIT_VERSION ||
+    files.size != existingByPath.size
+  ) {
+    return false
+  }
+
+  val seen = HashSet<String>(files.size)
+  return files.all { file ->
+    if (!seen.add(file.uri)) return@all false
+    val existing = existingByPath[file.uri] ?: return@all false
+    existing.mtime == file.lastModified && existing.size == file.size
+  }
+}
+
+private data class StagedLocalTrack(
+  val row: TrackEntity?,
+  val failed: Boolean,
+  val metadataChanged: Boolean,
+)
+
 private data class RemoteSyncHandle(
   val syncId: String,
   val sourceKey: String,
@@ -395,8 +472,11 @@ class AstraLibraryRepository private constructor(
     onProgress: (phase: String, processed: Int, total: Int, folderName: String) -> Unit,
     isCancelled: () -> Boolean = { false },
   ): NativeScanResult {
+    val timing = LocalScanTiming(folderId)
     initialize()
+    timing.beginLockWait()
     return catalogWriterMutex.withLock {
+      timing.acquiredLock()
       val userDao = requireUser().userDao()
       val folder = userDao.getFolder(folderId) ?: error("Folder $folderId does not exist")
       val database = requireCatalog()
@@ -417,6 +497,50 @@ class AstraLibraryRepository private constructor(
           updatedAt = startedAt,
         ),
       )
+      userDao.updateFolderScanState(folderId, folder.lastScannedAt, "scanning", null)
+      updateOperationalStatus(LibraryStatus.SCANNING)
+
+      try {
+        throwIfScanCancelled(isCancelled)
+        onProgress("discovering", 0, 0, folder.displayName)
+        val discoveryStarted = timing.now()
+        val files = discover(folder.treeUri)
+        timing.discoveryMs = timing.elapsedMs(discoveryStarted)
+        timing.files = files.size
+        throwIfScanCancelled(isCancelled)
+        onProgress("discovering", files.size, files.size, folder.displayName)
+
+        val comparisonStarted = timing.now()
+        val existing = dao.getActiveTrackEntitiesForSource(sourceKey)
+        val existingByPath = existing.associateBy(TrackEntity::path)
+        val seenPaths = files.mapTo(hashSetOf(), LocalAudioFile::uri)
+        val removed = existing.count { it.path !in seenPaths }
+        val canReuse = canReuseActiveLocalGeneration(
+          full = full,
+          previousSource = previousSource,
+          files = files,
+          existingByPath = existingByPath,
+        )
+        timing.comparisonMs = timing.elapsedMs(comparisonStarted)
+        throwIfScanCancelled(isCancelled)
+
+        if (canReuse) {
+          val revision = dao.getRevision()
+          userDao.updateFolderScanState(folderId, System.currentTimeMillis(), "ready", null)
+          scheduleSnapshot()
+          refreshReadyStatus()
+          timing.outcome = "unchanged"
+          return@withLock NativeScanResult(
+            added = 0,
+            updated = 0,
+            removed = 0,
+            errors = 0,
+            total = files.size,
+            revision = revision,
+          )
+        }
+
+        val extractionAndStagingStarted = timing.now()
         dao.insertGeneration(
           ScanGenerationEntity(
             id = generationId,
@@ -425,20 +549,6 @@ class AstraLibraryRepository private constructor(
             startedAt = startedAt,
           ),
         )
-      userDao.updateFolderScanState(folderId, folder.lastScannedAt, "scanning", null)
-      updateOperationalStatus(LibraryStatus.SCANNING)
-
-      try {
-        throwIfScanCancelled(isCancelled)
-        onProgress("discovering", 0, 0, folder.displayName)
-        val files = discover(folder.treeUri)
-        throwIfScanCancelled(isCancelled)
-        onProgress("discovering", files.size, files.size, folder.displayName)
-
-        val existing = dao.getActiveTrackEntitiesForSource(sourceKey)
-        val existingByPath = existing.associateBy(TrackEntity::path)
-        val seenPaths = files.mapTo(hashSetOf(), LocalAudioFile::uri)
-        val removed = existing.count { it.path !in seenPaths }
         var added = 0
         var updated = 0
         var errors = 0
@@ -456,7 +566,8 @@ class AstraLibraryRepository private constructor(
                   old.mtime == file.lastModified &&
                   old.size == file.size
                 if (unchanged) {
-                  old!!.copy(
+                  StagedLocalTrack(
+                    row = old!!.copy(
                       id = 0,
                       generationId = generationId,
                       sourceKey = sourceKey,
@@ -465,25 +576,32 @@ class AstraLibraryRepository private constructor(
                       albumSortKey = SortKeys.forText(old.album),
                       fileNameSortKey = SortKeys.forText(old.fileName),
                       sectionLabel = SortKeys.sectionLabel(old.title),
-                  ) to false
+                    ),
+                    failed = false,
+                    metadataChanged = false,
+                  )
                 } else {
                   val metadata = extract(file)
                   throwIfScanCancelled(isCancelled)
                   if (!metadata.ok) {
-                    if (old != null) {
-                      old.copy(id = 0, generationId = generationId, sourceKey = sourceKey) to true
+                    StagedLocalTrack(
+                      row = old?.copy(id = 0, generationId = generationId, sourceKey = sourceKey),
+                      failed = true,
+                      metadataChanged = false,
+                    )
                   } else {
-                      null to true
-                    }
-                  } else {
-                    trackFromMetadata(
+                    StagedLocalTrack(
+                      row = trackFromMetadata(
                         generationId = generationId,
                         sourceKey = sourceKey,
                         folderId = folderId,
                         file = file,
                         metadata = metadata,
                         addedAt = old?.addedAt ?: startedAt,
-                    ) to false
+                      ),
+                      failed = false,
+                      metadataChanged = true,
+                    )
                   }
                 }
               }
@@ -491,21 +609,25 @@ class AstraLibraryRepository private constructor(
           }
           throwIfScanCancelled(isCancelled)
           val insertRows = ArrayList<TrackEntity>(rows.size)
-          for ((row, failed) in rows) {
-            if (failed) errors += 1
-            if (row == null) continue
+          for (staged in rows) {
+            if (staged.failed) errors += 1
+            val row = staged.row ?: continue
             insertRows += row
-            if (existingByPath.containsKey(row.path)) updated += if (failed) 0 else 1 else added += 1
+            if (staged.metadataChanged) {
+              if (existingByPath.containsKey(row.path)) updated += 1 else added += 1
+            }
           }
           if (insertRows.isNotEmpty()) dao.putTracks(insertRows)
           processed += batch.size
           onProgress("extracting", processed, files.size, folder.displayName)
         }
+        timing.extractionAndStagingMs = timing.elapsedMs(extractionAndStagingStarted)
 
         throwIfScanCancelled(isCancelled)
         val prospective = dao.getProspectiveTracks(sourceKey, generationId)
         val nextRevision = dao.getRevision() + 1
         onProgress("indexing", prospective.size, prospective.size, folder.displayName)
+        val readModelStarted = timing.now()
         val readModels = withContext(Dispatchers.Default) {
           CatalogReadModelBuilder.build(
             prospective,
@@ -513,9 +635,11 @@ class AstraLibraryRepository private constructor(
             userDao.getFolders().associateBy(FolderEntity::id),
           )
         }
+        timing.readModelMs = timing.elapsedMs(readModelStarted)
         // Publishing is one Room transaction. Honour cancellation immediately before
         // it starts; once inside, let it finish so the active catalog stays coherent.
         throwIfScanCancelled(isCancelled)
+        val publishStarted = timing.now()
         val revision = dao.publishGeneration(
           sourceKey = sourceKey,
           generationId = generationId,
@@ -533,6 +657,8 @@ class AstraLibraryRepository private constructor(
         scheduleSnapshot()
         refreshReadyStatus()
         for (listener in catalogListeners) listener(revision)
+        timing.publishMs = timing.elapsedMs(publishStarted)
+        timing.outcome = "published"
         NativeScanResult(
           added = added,
           updated = updated,
@@ -542,6 +668,7 @@ class AstraLibraryRepository private constructor(
           revision = revision,
         )
       } catch (_: ScanCancelledException) {
+        timing.outcome = "cancelled"
         dao.deleteGenerationTracks(generationId)
         dao.deleteGeneration(generationId)
         userDao.updateFolderScanState(
@@ -562,6 +689,7 @@ class AstraLibraryRepository private constructor(
           cancelled = true,
         )
       } catch (error: Throwable) {
+        timing.outcome = "failed"
         runCatching {
           dao.deleteGenerationTracks(generationId)
           dao.setGenerationState(
@@ -586,8 +714,11 @@ class AstraLibraryRepository private constructor(
           recoveryNotice = currentStatus.recoveryNotice,
         )
         scheduleSnapshot()
+        timing.logIfDebuggable(applicationContext)
         throw error
       }
+    }.also {
+      timing.logIfDebuggable(applicationContext)
     }
   }
 

modules/astra-library-scanner/android/src/test/java/expo/modules/astralibraryscanner/data/LocalScanSnapshotTest.kt

@@ -0,0 +1,175 @@
+package expo.modules.astralibraryscanner.data
+
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class LocalScanSnapshotTest {
+  @Test
+  fun identicalSnapshotCanReuseActiveGenerationRegardlessOfDiscoveryOrder() {
+    val existing = listOf(
+      track("content://music/a.flac", size = 100, mtime = 10),
+      track("content://music/b.flac", size = 200, mtime = 20),
+    ).associateBy(TrackEntity::path)
+    val files = listOf(
+      file("content://music/b.flac", size = 200, mtime = 20),
+      file("content://music/a.flac", size = 100, mtime = 10),
+    )
+
+    assertTrue(canReuseActiveLocalGeneration(false, activeSource(), files, existing))
+  }
+
+  @Test
+  fun additionsAndRemovalsRequirePublishing() {
+    val existing = listOf(
+      track("content://music/a.flac", size = 100, mtime = 10),
+      track("content://music/b.flac", size = 200, mtime = 20),
+    ).associateBy(TrackEntity::path)
+
+    assertFalse(
+      canReuseActiveLocalGeneration(
+        false,
+        activeSource(),
+        listOf(file("content://music/a.flac", size = 100, mtime = 10)),
+        existing,
+      ),
+    )
+    assertFalse(
+      canReuseActiveLocalGeneration(
+        false,
+        activeSource(),
+        listOf(
+          file("content://music/a.flac", size = 100, mtime = 10),
+          file("content://music/b.flac", size = 200, mtime = 20),
+          file("content://music/c.flac", size = 300, mtime = 30),
+        ),
+        existing,
+      ),
+    )
+  }
+
+  @Test
+  fun sizeOrModificationChangesRequirePublishing() {
+    val path = "content://music/a.flac"
+    val existing = mapOf(path to track(path, size = 100, mtime = 10))
+
+    assertFalse(
+      canReuseActiveLocalGeneration(
+        false,
+        activeSource(),
+        listOf(file(path, size = 101, mtime = 10)),
+        existing,
+      ),
+    )
+    assertFalse(
+      canReuseActiveLocalGeneration(
+        false,
+        activeSource(),
+        listOf(file(path, size = 100, mtime = 11)),
+        existing,
+      ),
+    )
+  }
+
+  @Test
+  fun matchingNullableSizesCanReuseActiveGeneration() {
+    val path = "content://music/unknown-size.flac"
+    val existing = mapOf(path to track(path, size = null, mtime = 0))
+
+    assertTrue(
+      canReuseActiveLocalGeneration(
+        false,
+        activeSource(),
+        listOf(file(path, size = null, mtime = 0)),
+        existing,
+      ),
+    )
+  }
+
+  @Test
+  fun duplicateDiscoveredUrisRequirePublishing() {
+    val first = "content://music/a.flac"
+    val second = "content://music/b.flac"
+    val existing = listOf(
+      track(first, size = 100, mtime = 10),
+      track(second, size = 100, mtime = 10),
+    ).associateBy(TrackEntity::path)
+
+    assertFalse(
+      canReuseActiveLocalGeneration(
+        false,
+        activeSource(),
+        listOf(file(first, size = 100, mtime = 10), file(first, size = 100, mtime = 10)),
+        existing,
+      ),
+    )
+  }
+
+  @Test
+  fun fullMissingAndStaleGenerationsCannotBeReused() {
+    val path = "content://music/a.flac"
+    val files = listOf(file(path, size = 100, mtime = 10))
+    val existing = mapOf(path to track(path, size = 100, mtime = 10))
+
+    assertFalse(canReuseActiveLocalGeneration(true, activeSource(), files, existing))
+    assertFalse(
+      canReuseActiveLocalGeneration(
+        false,
+        activeSource().copy(activeGenerationId = null),
+        files,
+        existing,
+      ),
+    )
+    assertFalse(
+      canReuseActiveLocalGeneration(
+        false,
+        activeSource().copy(artistCreditVersion = LEGACY_ARTIST_CREDIT_VERSION),
+        files,
+        existing,
+      ),
+    )
+  }
+
+  private fun activeSource(): CatalogSourceEntity = CatalogSourceEntity(
+    sourceKey = "local:1",
+    sourceType = "local",
+    sourceId = 1,
+    activeGenerationId = "active",
+    updatedAt = 1,
+    artistCreditVersion = CURRENT_ARTIST_CREDIT_VERSION,
+  )
+
+  private fun file(path: String, size: Long?, mtime: Long): LocalAudioFile = LocalAudioFile(
+    uri = path,
+    name = path.substringAfterLast('/'),
+    size = size,
+    lastModified = mtime,
+    mimeType = "audio/flac",
+    parentUri = "content://music",
+    coverUri = null,
+  )
+
+  private fun track(path: String, size: Long?, mtime: Long): TrackEntity = TrackEntity(
+    generationId = "active",
+    sourceKey = "local:1",
+    path = path,
+    folderId = 1,
+    title = path.substringAfterLast('/'),
+    artist = "Artist",
+    album = "Album",
+    albumIdentityKey = "album",
+    format = "FLAC",
+    fileName = path.substringAfterLast('/'),
+    size = size,
+    mtime = mtime,
+    addedAt = 1,
+    modifiedAt = mtime,
+    titleSortKey = "title",
+    artistSortKey = "artist",
+    albumSortKey = "album",
+    fileNameSortKey = "file",
+    discSort = 0,
+    trackSort = 0,
+    sectionLabel = "A",
+  )
+}