From 7e7ddeb9e21456a1a78acc6162e4dd9e6a5725d3 Mon Sep 17 00:00:00 2001
From: topjohnwu <topjohnwu@gmail.com>
Date: Mon, 28 Mar 2022 00:59:16 -0700
Subject: [PATCH] Cleanup database migration code

---
 native/jni/core/db.cpp | 67 +++++++++++++++++++++++++-----------------
 1 file changed, 40 insertions(+), 27 deletions(-)

diff --git a/native/jni/core/db.cpp b/native/jni/core/db.cpp
index 7bcf0505a..8e3c51d0f 100644
--- a/native/jni/core/db.cpp
+++ b/native/jni/core/db.cpp
@@ -154,45 +154,58 @@ static char *open_and_init_db(sqlite3 *&db) {
         sqlite3_close(db);
         return strdup("Downgrading database is not supported");
     }
-    if (ver < 3) {
-        // Policies
+
+    auto create_policy = [&] {
         sqlite3_exec(db,
                 "CREATE TABLE IF NOT EXISTS policies "
                 "(uid INT, package_name TEXT, policy INT, until INT, "
                 "logging INT, notification INT, PRIMARY KEY(uid))",
                 nullptr, nullptr, &err);
-        err_ret(err);
-        // Settings
+    };
+    auto create_settings = [&] {
         sqlite3_exec(db,
                 "CREATE TABLE IF NOT EXISTS settings "
                 "(key TEXT, value INT, PRIMARY KEY(key))",
                 nullptr, nullptr, &err);
-        err_ret(err);
-        ver = 3;
-        upgrade = true;
-    }
-    if (ver < 4) {
-        // Strings
+    };
+    auto create_strings = [&] {
         sqlite3_exec(db,
                 "CREATE TABLE IF NOT EXISTS strings "
                 "(key TEXT, value TEXT, PRIMARY KEY(key))",
                 nullptr, nullptr, &err);
-        err_ret(err);
-        /* Directly jump to version 6 */
-        ver = 6;
-        upgrade = true;
-    }
-    if (ver < 7) {
+    };
+    auto create_denylist = [&] {
         sqlite3_exec(db,
-                "CREATE TABLE IF NOT EXISTS hidelist "
-                "(package_name TEXT, process TEXT, PRIMARY KEY(package_name, process));",
+                "CREATE TABLE IF NOT EXISTS denylist "
+                "(package_name TEXT, process TEXT, PRIMARY KEY(package_name, process))",
                 nullptr, nullptr, &err);
+    };
+
+    // Database changelog:
+    //
+    // 0 - 6: DB stored in app private data. There are no longer any code in the project to
+    //        migrate these data, so no need to take any of these versions into consideration.
+    // 7 : create table 'hidelist' (process TEXT, PRIMARY KEY(process))
+    // 8 : add new column (package_name TEXT) to table 'hidelist'
+    // 9 : rebuild table 'hidelist' to update primary key (PRIMARY KEY(package_name, process))
+    // 10: remove table 'logs'
+    // 11: remove table 'hidelist' and create table 'denylist' (same data structure)
+
+    if (/* 0, 1, 2, 3, 4, 5, 6 */ ver <= 6) {
+        create_policy();
         err_ret(err);
-        /* Directly jump to version 9 */
-        ver = 9;
+        create_settings();
+        err_ret(err);
+        create_strings();
+        err_ret(err);
+        create_denylist();
+        err_ret(err);
+
+        // Directly jump to latest
+        ver = DB_VERSION;
         upgrade = true;
     }
-    if (ver < 8) {
+    if (ver == 7) {
         sqlite3_exec(db,
                 "BEGIN TRANSACTION;"
                 "ALTER TABLE hidelist RENAME TO hidelist_tmp;"
@@ -203,11 +216,11 @@ static char *open_and_init_db(sqlite3 *&db) {
                 "COMMIT;",
                 nullptr, nullptr, &err);
         err_ret(err);
-        /* Directly jump to version 9 */
+        // Directly jump to version 9
         ver = 9;
         upgrade = true;
     }
-    if (ver < 9) {
+    if (ver == 8) {
         sqlite3_exec(db,
                 "BEGIN TRANSACTION;"
                 "ALTER TABLE hidelist RENAME TO hidelist_tmp;"
@@ -221,20 +234,20 @@ static char *open_and_init_db(sqlite3 *&db) {
         ver = 9;
         upgrade = true;
     }
-    if (ver < 10) {
+    if (ver == 9) {
         sqlite3_exec(db, "DROP TABLE IF EXISTS logs", nullptr, nullptr, &err);
         err_ret(err);
         ver = 10;
         upgrade = true;
     }
-    if (ver < 11) {
+    if (ver == 10) {
         sqlite3_exec(db,
                 "DROP TABLE IF EXISTS hidelist;"
-                "CREATE TABLE IF NOT EXISTS denylist "
-                "(package_name TEXT, process TEXT, PRIMARY KEY(package_name, process));"
                 "DELETE FROM settings WHERE key='magiskhide';",
                 nullptr, nullptr, &err);
         err_ret(err);
+        create_denylist();
+        err_ret(err);
         ver = 11;
         upgrade = true;
     }