From 431e366e76b3c04d2b4a920262e18f3e3c76154c Mon Sep 17 00:00:00 2001
From: Greyson Parrelli <greyson@signal.org>
Date: Tue, 14 Mar 2023 11:51:21 -0400
Subject: [PATCH] Add in possible recovery for DB error handler.

A bad FTS index can result in the corruption handler being triggered.
We can attempt to rebuild it to see if that helps.
---
 .../securesms/database/SearchTable.kt         | 36 +++++++++++++++++--
 .../database/SqlCipherErrorHandler.kt         |  9 +++++
 2 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/app/src/main/java/org/thoughtcrime/securesms/database/SearchTable.kt b/app/src/main/java/org/thoughtcrime/securesms/database/SearchTable.kt
index 1a31005a1d..fdc61e66a4 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/database/SearchTable.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/database/SearchTable.kt
@@ -34,20 +34,24 @@ class SearchTable(context: Context, databaseHelper: SignalDatabase) : DatabaseTa
       "CREATE VIRTUAL TABLE $FTS_TABLE_NAME USING fts5($BODY, $THREAD_ID UNINDEXED, content=${MessageTable.TABLE_NAME}, content_rowid=${MessageTable.ID})"
     )
 
+    private const val TRIGGER_AFTER_INSERT = "message_ai"
+    private const val TRIGGER_AFTER_DELETE = "message_ad"
+    private const val TRIGGER_AFTER_UPDATE = "message_au"
+
     @Language("sql")
     val CREATE_TRIGGERS = arrayOf(
       """
-        CREATE TRIGGER message_ai AFTER INSERT ON ${MessageTable.TABLE_NAME} BEGIN
+        CREATE TRIGGER $TRIGGER_AFTER_INSERT AFTER INSERT ON ${MessageTable.TABLE_NAME} BEGIN
           INSERT INTO $FTS_TABLE_NAME($ID, $BODY, $THREAD_ID) VALUES (new.${MessageTable.ID}, new.${MessageTable.BODY}, new.${MessageTable.THREAD_ID});
         END;
       """,
       """
-        CREATE TRIGGER message_ad AFTER DELETE ON ${MessageTable.TABLE_NAME} BEGIN
+        CREATE TRIGGER $TRIGGER_AFTER_DELETE AFTER DELETE ON ${MessageTable.TABLE_NAME} BEGIN
           INSERT INTO $FTS_TABLE_NAME($FTS_TABLE_NAME, $ID, $BODY, $THREAD_ID) VALUES('delete', old.${MessageTable.ID}, old.${MessageTable.BODY}, old.${MessageTable.THREAD_ID});
         END;
       """,
       """
-        CREATE TRIGGER message_au AFTER UPDATE ON ${MessageTable.TABLE_NAME} BEGIN
+        CREATE TRIGGER $TRIGGER_AFTER_UPDATE AFTER UPDATE ON ${MessageTable.TABLE_NAME} BEGIN
           INSERT INTO $FTS_TABLE_NAME($FTS_TABLE_NAME, $ID, $BODY, $THREAD_ID) VALUES('delete', old.${MessageTable.ID}, old.${MessageTable.BODY}, old.${MessageTable.THREAD_ID});
           INSERT INTO $FTS_TABLE_NAME($ID, $BODY, $THREAD_ID) VALUES (new.${MessageTable.ID}, new.${MessageTable.BODY}, new.${MessageTable.THREAD_ID});
         END;
@@ -217,6 +221,32 @@ class SearchTable(context: Context, databaseHelper: SignalDatabase) : DatabaseTa
     return true
   }
 
+  /**
+   * Drops all tables and recreates them. Should only be done in extreme circumstances.
+   */
+  fun fullyResetTables() {
+    Log.w(TAG, "[fullyResetTables] Dropping tables and triggers...")
+    writableDatabase.execSQL("DROP TABLE IF EXISTS $FTS_TABLE_NAME")
+    writableDatabase.execSQL("DROP TABLE IF EXISTS ${FTS_TABLE_NAME}_config")
+    writableDatabase.execSQL("DROP TABLE IF EXISTS ${FTS_TABLE_NAME}_content")
+    writableDatabase.execSQL("DROP TABLE IF EXISTS ${FTS_TABLE_NAME}_data")
+    writableDatabase.execSQL("DROP TABLE IF EXISTS ${FTS_TABLE_NAME}_idx")
+    writableDatabase.execSQL("DROP TRIGGER IF EXISTS $TRIGGER_AFTER_INSERT")
+    writableDatabase.execSQL("DROP TRIGGER IF EXISTS $TRIGGER_AFTER_DELETE")
+    writableDatabase.execSQL("DROP TRIGGER IF EXISTS $TRIGGER_AFTER_UPDATE")
+
+    Log.w(TAG, "[fullyResetTables] Recreating table...")
+    CREATE_TABLE.forEach { writableDatabase.execSQL(it) }
+
+    Log.w(TAG, "[fullyResetTables] Recreating triggers...")
+    CREATE_TRIGGERS.forEach { writableDatabase.execSQL(it) }
+
+    Log.w(TAG, "[fullyResetTables] Rebuilding index...")
+    rebuildIndex()
+
+    Log.w(TAG, "[fullyResetTables] Done")
+  }
+
   private fun createFullTextSearchQuery(query: String): String {
     return query
       .split(" ")
diff --git a/app/src/main/java/org/thoughtcrime/securesms/database/SqlCipherErrorHandler.kt b/app/src/main/java/org/thoughtcrime/securesms/database/SqlCipherErrorHandler.kt
index 10fbd62b79..246f3ba2ec 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/database/SqlCipherErrorHandler.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/database/SqlCipherErrorHandler.kt
@@ -30,6 +30,7 @@ class SqlCipherErrorHandler(private val databaseName: String) : DatabaseErrorHan
 
     if (result is DiagnosticResults.Success) {
       if (result.pragma1Passes && result.pragma2Passes) {
+        attemptToClearFullTextSearchIndex()
         throw DatabaseCorruptedError_BothChecksPass(lines)
       } else if (!result.pragma1Passes && result.pragma2Passes) {
         throw DatabaseCorruptedError_NormalCheckFailsCipherCheckPasses(lines)
@@ -138,6 +139,14 @@ class SqlCipherErrorHandler(private val databaseName: String) : DatabaseErrorHan
     }
   }
 
+  private fun attemptToClearFullTextSearchIndex() {
+    try {
+      SignalDatabase.messageSearch.fullyResetTables()
+    } catch (e: Throwable) {
+      Log.w(TAG, "Failed to clear full text search index.", e)
+    }
+  }
+
   private sealed class DiagnosticResults(val logs: String) {
     class Success(
       val pragma1Passes: Boolean,