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ext/libpqxx-7.7.3/install/ubuntu22.04/arm64/include/pqxx/transaction.hxx

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+/* Definition of the pqxx::transaction class.
+ * pqxx::transaction represents a standard database transaction.
+ *
+ * DO NOT INCLUDE THIS FILE DIRECTLY; include pqxx/transaction instead.
+ *
+ * Copyright (c) 2000-2022, Jeroen T. Vermeulen.
+ *
+ * See COPYING for copyright license.  If you did not receive a file called
+ * COPYING with this source code, please notify the distributor of this
+ * mistake, or contact the author.
+ */
+#ifndef PQXX_H_TRANSACTION
+#define PQXX_H_TRANSACTION
+
+#if !defined(PQXX_HEADER_PRE)
+#  error "Include libpqxx headers as <pqxx/header>, not <pqxx/header.hxx>."
+#endif
+
+#include "pqxx/dbtransaction.hxx"
+
+namespace pqxx::internal
+{
+/// Helper base class for the @ref transaction class template.
+class PQXX_LIBEXPORT basic_transaction : public dbtransaction
+{
+protected:
+  basic_transaction(
+    connection &c, zview begin_command, std::string_view tname);
+  basic_transaction(connection &c, zview begin_command, std::string &&tname);
+  basic_transaction(connection &c, zview begin_command);
+
+  virtual ~basic_transaction() noexcept override = 0;
+
+private:
+  virtual void do_commit() override;
+};
+} // namespace pqxx::internal
+
+
+namespace pqxx
+{
+/**
+ * @ingroup transactions
+ */
+//@{
+
+/// Standard back-end transaction, templatised on isolation level.
+/** This is the type you'll normally want to use to represent a transaction on
+ * the database.
+ *
+ * Usage example: double all wages.
+ *
+ * ```cxx
+ * extern connection C;
+ * work T(C);
+ * try
+ * {
+ *   T.exec0("UPDATE employees SET wage=wage*2");
+ *   T.commit();	// NOTE: do this inside try block
+ * }
+ * catch (exception const &e)
+ * {
+ *   cerr << e.what() << endl;
+ *   T.abort();		// Usually not needed; same happens when T's life ends.
+ * }
+ * ```
+ */
+template<
+  isolation_level ISOLATION = isolation_level::read_committed,
+  write_policy READWRITE = write_policy::read_write>
+class transaction final : public internal::basic_transaction
+{
+public:
+  /// Begin a transaction.
+  /**
+   * @param c Connection for this transaction to operate on.
+   * @param tname Optional name for transaction.  Must begin with a letter and
+   * may contain letters and digits only.
+   */
+  transaction(connection &c, std::string_view tname) :
+          internal::basic_transaction{
+            c, internal::begin_cmd<ISOLATION, READWRITE>, tname}
+  {}
+
+  /// Begin a transaction.
+  /**
+   * @param c Connection for this transaction to operate on.
+   * may contain letters and digits only.
+   */
+  explicit transaction(connection &c) :
+          internal::basic_transaction{
+            c, internal::begin_cmd<ISOLATION, READWRITE>}
+  {}
+
+  virtual ~transaction() noexcept override { close(); }
+};
+
+
+/// The default transaction type.
+using work = transaction<>;
+
+/// Read-only transaction.
+using read_transaction =
+  transaction<isolation_level::read_committed, write_policy::read_only>;
+
+//@}
+} // namespace pqxx
+#endif