Support recusrive transactions in sqlite usage

GitOrigin-RevId: 1afd836ebd0c8b1cc79c86c9ef548deeb3f5adaa

tddb/td/db/SqliteDb.cpp

@@ -136,10 +136,18 @@ Status SqliteDb::set_user_version(int32 version) {
 }
 
 Status SqliteDb::begin_transaction() {
-  return exec("BEGIN");
+  if (raw_->on_begin()) {
+    return exec("BEGIN");
+  }
+  return Status::OK();
 }
+
 Status SqliteDb::commit_transaction() {
-  return exec("COMMIT");
+  TRY_RESULT(need_commit, raw_->on_commit());
+  if (need_commit) {
+    return exec("COMMIT");
+  }
+  return Status::OK();
 }
 
 bool SqliteDb::is_encrypted() {

tddb/td/db/detail/RawSqliteDb.h

@@ -44,9 +44,22 @@ class RawSqliteDb {
   Status last_error();
   static Status last_error(sqlite3 *db);
 
+  bool on_begin() {
+    begin_cnt_++;
+    return begin_cnt_ == 1;
+  }
+  Result<bool> on_commit() {
+    if (begin_cnt_ == 0) {
+      return Status::Error("No matching begin for commit");
+    }
+    begin_cnt_--;
+    return begin_cnt_ == 0;
+  }
+
  private:
   sqlite3 *db_;
   std::string path_;
+  size_t begin_cnt_{0};
 };
 
 }  // namespace detail