Improve the performance of the migration by ~4x.

app/src/main/java/org/thoughtcrime/securesms/database/MessageTable.java

@@ -3721,6 +3721,15 @@ public class MessageTable extends DatabaseTable implements MmsSmsColumns, Recipi
     getWritableDatabase().update(TABLE_NAME, values, THREAD_ID + " = ?", SqlUtil.buildArgs(fromId));
   }
 
+  /**
+   * Returns the next ID that would be generated if an insert was done on this table.
+   * You should *not* use this for actually generating an ID to use. That will happen automatically!
+   * This was added for a very narrow usecase, and you probably don't need to use it.
+   */
+  public long getNextId() {
+    return SqlUtil.getNextAutoIncrementId(getWritableDatabase(), TABLE_NAME);
+  }
+
   void updateReactionsUnread(SQLiteDatabase db, long messageId, boolean hasReactions, boolean isRemoval) {
     try {
       boolean       isOutgoing = getMessageRecord(messageId).isOutgoing();

app/src/main/java/org/thoughtcrime/securesms/database/SearchTable.kt

@@ -6,6 +6,7 @@ import android.database.Cursor
 import android.text.TextUtils
 import org.intellij.lang.annotations.Language
 import org.signal.core.util.SqlUtil
+import org.signal.core.util.logging.Log
 
 /**
  * Contains all databases necessary for full-text search (FTS).
@@ -13,6 +14,8 @@ import org.signal.core.util.SqlUtil
 @SuppressLint("RecipientIdDatabaseReferenceUsage", "ThreadIdDatabaseReferenceUsage") // Handles updates via triggers
 class SearchTable(context: Context, databaseHelper: SignalDatabase) : DatabaseTable(context, databaseHelper) {
   companion object {
+    private val TAG = Log.tag(SearchTable::class.java)
+
     const val MMS_FTS_TABLE_NAME = "mms_fts"
     const val ID = "rowid"
     const val BODY = MmsSmsColumns.BODY
@@ -111,6 +114,38 @@ class SearchTable(context: Context, databaseHelper: SignalDatabase) : DatabaseTa
     }
   }
 
+  /**
+   * Re-adds every message to the index. It's fine to insert the same message twice; the table will naturally de-dupe.
+   *
+   * In order to prevent the database from locking up with super large inserts, this will perform the re-index in batches of the size you specify.
+   * It is not guaranteed that every batch will be the same size, but rather that the batches will be _no larger_ than the specified size.
+   *
+   * Warning: This is a potentially extremely-costly operation! It can take 10+ seconds on large installs and/or slow devices.
+   * Be smart about where you call this.
+   */
+  fun rebuildIndex(batchSize: Long = 10_000L) {
+    val maxId: Long = SignalDatabase.messages.nextId
+
+    Log.i(TAG, "Re-indexing. Operating on ID's 1-$maxId in steps of $batchSize.")
+
+    for (i in 1..maxId step batchSize) {
+      Log.i(TAG, "Reindexing ID's [$i, ${i + batchSize})")
+      writableDatabase.execSQL(
+        """
+        INSERT INTO $MMS_FTS_TABLE_NAME ($ID, $BODY) 
+            SELECT 
+              ${MessageTable.ID}, 
+              ${MessageTable.BODY}
+            FROM 
+              ${MessageTable.TABLE_NAME} 
+            WHERE 
+              ${MessageTable.ID} >= $i AND
+              ${MessageTable.ID} < ${i + batchSize}
+        """.trimIndent()
+      )
+    }
+  }
+
   private fun createFullTextSearchQuery(query: String): String {
     return query
       .split(" ")

app/src/main/java/org/thoughtcrime/securesms/database/helpers/migration/V168_SingleMessageTableMigration.kt

@@ -3,14 +3,42 @@ package org.thoughtcrime.securesms.database.helpers.migration
 import android.app.Application
 import net.zetetic.database.sqlcipher.SQLiteDatabase
 import org.signal.core.util.SqlUtil
+import org.signal.core.util.Stopwatch
+import org.signal.core.util.logging.Log
 
 object V168_SingleMessageTableMigration : SignalDatabaseMigration {
+  private val TAG = Log.tag(V168_SingleMessageTableMigration::class.java)
+
   override fun migrate(context: Application, db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
+    val stopwatch = Stopwatch("migration")
+
     val nextMmsId = SqlUtil.getNextAutoIncrementId(db, "mms")
+    stopwatch.split("next-id")
 
     db.execSQL("DROP TRIGGER msl_sms_delete")
     db.execSQL("DROP TRIGGER reactions_sms_delete")
+    db.execSQL("DROP TRIGGER sms_ai")
+    db.execSQL("DROP TRIGGER sms_au")
+    db.execSQL("DROP TRIGGER sms_ad")
     db.execSQL("DROP TABLE sms_fts") // Will drop all other related fts tables
+    stopwatch.split("drop-triggers")
+
+    // It's actually much faster to drop the indexes, copy the data, then recreate the indexes in bulk than it is to keep them and index-as-you-insert.
+    // Like, at least twice as fast.
+    db.execSQL("DROP INDEX mms_read_and_notified_and_thread_id_index")
+    db.execSQL("DROP INDEX mms_type_index")
+    db.execSQL("DROP INDEX mms_date_sent_index")
+    db.execSQL("DROP INDEX mms_date_server_index")
+    db.execSQL("DROP INDEX mms_thread_date_index")
+    db.execSQL("DROP INDEX mms_reactions_unread_index")
+    db.execSQL("DROP INDEX mms_story_type_index")
+    db.execSQL("DROP INDEX mms_parent_story_id_index")
+    db.execSQL("DROP INDEX mms_thread_story_parent_story_index")
+    db.execSQL("DROP INDEX mms_quote_id_quote_author_index")
+    db.execSQL("DROP INDEX mms_exported_index")
+    db.execSQL("DROP INDEX mms_id_type_payment_transactions_index")
+    db.execSQL("DROP TRIGGER mms_ai") // Note: For perf reasons, we won't actually rebuild the index here -- we'll rebuild it asynchronously in a job
+    stopwatch.split("drop-mms-indexes")
 
     db.execSQL(
       """
@@ -66,8 +94,31 @@ object V168_SingleMessageTableMigration : SignalDatabaseMigration {
         FROM sms
     """
     )
+    stopwatch.split("copy-sms")
 
     db.execSQL("DROP TABLE sms")
+    stopwatch.split("drop-sms")
+
+    db.execSQL("CREATE INDEX mms_read_and_notified_and_thread_id_index ON mms(read, notified, thread_id)")
+    db.execSQL("CREATE INDEX mms_type_index ON mms (type)")
+    db.execSQL("CREATE INDEX mms_date_sent_index ON mms (date_sent, recipient_id, thread_id)")
+    db.execSQL("CREATE INDEX mms_date_server_index ON mms (date_server)")
+    db.execSQL("CREATE INDEX mms_thread_date_index ON mms (thread_id, date_received)")
+    db.execSQL("CREATE INDEX mms_reactions_unread_index ON mms (reactions_unread)")
+    db.execSQL("CREATE INDEX mms_story_type_index ON mms (story_type)")
+    db.execSQL("CREATE INDEX mms_parent_story_id_index ON mms (parent_story_id)")
+    db.execSQL("CREATE INDEX mms_thread_story_parent_story_index ON mms (thread_id, date_received, story_type, parent_story_id)")
+    db.execSQL("CREATE INDEX mms_quote_id_quote_author_index ON mms (quote_id, quote_author)")
+    db.execSQL("CREATE INDEX mms_exported_index ON mms (exported)")
+    db.execSQL("CREATE INDEX mms_id_type_payment_transactions_index ON mms (_id, type) WHERE type & ${0x300000000L} != 0")
+    db.execSQL(
+      """
+        CREATE TRIGGER mms_ai AFTER INSERT ON mms BEGIN
+          INSERT INTO mms_fts (rowid, body, thread_id) VALUES (new._id, new.body, new.thread_id);
+        END;
+      """
+    )
+    stopwatch.split("rebuild-indexes")
 
     db.execSQL(
       """
@@ -76,6 +127,7 @@ object V168_SingleMessageTableMigration : SignalDatabaseMigration {
       WHERE is_mms = 0
     """
     )
+    stopwatch.split("update-reactions")
 
     db.execSQL(
       """
@@ -84,8 +136,10 @@ object V168_SingleMessageTableMigration : SignalDatabaseMigration {
       WHERE is_mms = 0
     """
     )
+    stopwatch.split("update-msl")
+
+    stopwatch.stop(TAG)
 
-    // TODO search index?
     // TODO jobs?
   }
 }