make file restore numbers add up by showing duplicates and errors

storage/demo/src/main/java/de/grobox/storagebackuptester/restore/RestoreStats.kt

@@ -13,7 +13,6 @@ import de.grobox.storagebackuptester.backup.getSpeed
 import org.calyxos.backup.storage.api.BackupFile
 import org.calyxos.backup.storage.restore.NotificationRestoreObserver
 import kotlin.time.DurationUnit
-import kotlin.time.ExperimentalTime
 import kotlin.time.toDuration
 
 data class RestoreProgress(
@@ -41,6 +40,10 @@ class RestoreStats(
         liveData.postValue(RestoreProgress(filesProcessed, totalFiles, text))
     }
 
+    override fun onFileDuplicatesRemoved(num: Int) {
+        // no-op
+    }
+
     override fun onFileRestored(
         file: BackupFile,
         bytesWritten: Long,
@@ -68,7 +71,6 @@ class RestoreStats(
         liveData.postValue(RestoreProgress(filesProcessed, totalFiles))
     }
 
-    @OptIn(ExperimentalTime::class)
     override fun onRestoreComplete(restoreDuration: Long) {
         super.onRestoreComplete(restoreDuration)
         val sb = StringBuilder("\n")

storage/lib/src/main/java/org/calyxos/backup/storage/api/RestoreObserver.kt

@@ -7,6 +7,7 @@ package org.calyxos.backup.storage.api
 
 public interface RestoreObserver {
     public fun onRestoreStart(numFiles: Int, totalSize: Long)
+    public fun onFileDuplicatesRemoved(num: Int)
     public fun onFileRestored(file: BackupFile, bytesWritten: Long, tag: String)
 
     /**

storage/lib/src/main/java/org/calyxos/backup/storage/restore/FileSplitter.kt

@@ -21,24 +21,32 @@ internal data class RestorableChunk(
 
     /**
      * Call this after the RestorableChunk is complete and **before** using it for restore.
+     *
+     * @return the number of duplicate files removed
      */
-    fun finalize() {
+    fun finalize(): Int {
         // entries in the zip chunk need to be sorted by their index in the zip
         files.sortBy { it.zipIndex }
         // There might be duplicates in case the *exact* same set of files exists more than once
         // so they'll produce the same chunk ID.
         // But since the content is there and this is an unlikely scenario, we drop the duplicates.
         var lastIndex = 0
+        var numRemoved = 0
         val iterator = files.iterator()
         while (iterator.hasNext()) {
             val file = iterator.next()
             val i = file.zipIndex
             when {
                 i < lastIndex -> error("unsorted list")
-                i == lastIndex -> iterator.remove() // remove duplicate
+                i == lastIndex -> { // remove duplicate
+                    numRemoved++
+                    iterator.remove()
+                }
+
                 i > lastIndex -> lastIndex = i // gaps are possible when we don't restore all files
             }
         }
+        return numRemoved
     }
 }
 
@@ -87,6 +95,14 @@ internal data class FileSplitterResult(
      * Files referenced in [multiChunkMap] sorted for restoring.
      */
     val multiChunkFiles: Collection<RestorableFile>,
+    /**
+     * The number of duplicate files that was removed from [zipChunks].
+     * Duplicate files in [zipChunks] with the same chunk ID will have the same index in the ZIP.
+     * So we remove them to make restore easier.
+     * With some extra work, we could restore those files,
+     * but by not doing so we are probably doing a favor to the user.
+     */
+    val numRemovedDuplicates: Int,
 )
 
 /**
@@ -121,14 +137,15 @@ internal object FileSplitter {
             }
         }
         // entries in the zip chunk need to be sorted by their index in the zip, duplicated removed
-        zipChunkMap.values.forEach { zipChunk -> zipChunk.finalize() }
+        val numRemovedDuplicates = zipChunkMap.values.sumOf { zipChunk -> zipChunk.finalize() }
         val singleChunks = chunkMap.values.filter { it.isSingle }
         val multiChunks = chunkMap.filterValues { !it.isSingle }
         return FileSplitterResult(
             zipChunks = zipChunkMap.values,
             singleChunks = singleChunks,
             multiChunkMap = multiChunks,
             multiChunkFiles = getMultiFiles(multiChunks),
+            numRemovedDuplicates = numRemovedDuplicates,
         )
     }
 
@@ -145,6 +162,7 @@ internal object FileSplitter {
                 f1.chunkIdsCount == f2.chunkIdsCount -> {
                     f1.chunkIds.joinToString().compareTo(f2.chunkIds.joinToString())
                 }
+
                 else -> 1
             }
         }

storage/lib/src/main/java/org/calyxos/backup/storage/restore/NotificationRestoreObserver.kt

@@ -18,13 +18,18 @@ public open class NotificationRestoreObserver internal constructor(private val n
 
     private var totalFiles = 0
     private var filesRestored = 0
+    private var filesRemovedAsDuplicates = 0
     private var filesWithError = 0
 
     override fun onRestoreStart(numFiles: Int, totalSize: Long) {
         totalFiles = numFiles
         n.updateRestoreNotification(filesRestored + filesWithError, totalFiles)
     }
 
+    override fun onFileDuplicatesRemoved(num: Int) {
+        filesRemovedAsDuplicates = num
+    }
+
     override fun onFileRestored(file: BackupFile, bytesWritten: Long, tag: String) {
         filesRestored++
         n.updateRestoreNotification(filesRestored + filesWithError, totalFiles)
@@ -36,7 +41,13 @@ public open class NotificationRestoreObserver internal constructor(private val n
     }
 
     override fun onRestoreComplete(restoreDuration: Long) {
-        n.showRestoreCompleteNotification(filesRestored, totalFiles, getRestoreCompleteIntent())
+        n.showRestoreCompleteNotification(
+            restored = filesRestored,
+            duplicates = filesRemovedAsDuplicates,
+            errors = filesWithError,
+            total = totalFiles,
+            intent = getRestoreCompleteIntent(),
+        )
     }
 
     protected open fun getRestoreCompleteIntent(): PendingIntent? {

storage/lib/src/main/java/org/calyxos/backup/storage/restore/Restore.kt

@@ -110,8 +110,10 @@ internal class Restore(
         observer?.onRestoreStart(filesTotal, totalSize)
 
         val split = FileSplitter.splitSnapshot(snapshot)
+        observer?.onFileDuplicatesRemoved(split.numRemovedDuplicates)
+        var restoredFiles = split.numRemovedDuplicates // count removed dups, so numbers add up
+
         val version = snapshot.version
-        var restoredFiles = 0
         val smallFilesDuration = measure {
             restoredFiles += zipChunkRestore.restore(
                 version,

storage/lib/src/main/java/org/calyxos/backup/storage/ui/Notifications.kt

@@ -116,13 +116,25 @@ internal class Notifications(private val context: Context) {
 
     internal fun showRestoreCompleteNotification(
         restored: Int,
+        duplicates: Int,
+        errors: Int,
         total: Int,
         intent: PendingIntent?,
     ) {
         val title = context.getString(R.string.notification_restore_complete_title, restored, total)
+        val msg = StringBuilder().apply {
+            if (duplicates > 0) {
+                append(context.getString(R.string.notification_restore_complete_dups, duplicates))
+            }
+            if (errors > 0) {
+                if (duplicates > 0) append("\n")
+                append(context.getString(R.string.notification_restore_complete_errors, errors))
+            }
+        }.toString().ifEmpty { null }
         val notification = NotificationCompat.Builder(context, CHANNEL_ID_BACKUP).apply {
             setSmallIcon(R.drawable.ic_cloud_done)
             setContentTitle(title)
+            setContentText(msg)
             setOngoing(false)
             setShowWhen(true)
             setAutoCancel(true)

storage/lib/src/main/res/values/strings.xml

@@ -18,6 +18,8 @@
     <string name="notification_restore_title">Restoring files…</string>
     <string name="notification_restore_info">%1$d/%2$d</string>
     <string name="notification_restore_complete_title">%1$d of %2$d files restored</string>
+    <string name="notification_restore_complete_dups">%1$d files were duplicates.</string>
+    <string name="notification_restore_complete_errors">%1$d files had errors.</string>
 
     <string name="snapshots_title">Available storage backups</string>
     <string name="snapshots_empty">No storage backups found\n\nSorry, but there is nothing that can be restored.</string>