/*
 * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; version 2 of the
 * License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301  USA
 */
syntax = "proto2";

// ifdef PROTOBUF_LITE: option optimize_for = LITE_RUNTIME;

// Expect operations
package Polarx.Expect;
option java_package = "com.mysql.cj.polarx.protobuf";

// Pipelining messages is a core feature of the Polarx Protocol. It
// sends messages to the server without waiting for a response to
// save latency.
//
// * in case of success the time to wait and check the result as been saved
//   and the latency is reduced.
//
// * in the case of an error a mechanism is need to ensure that the following
//   messages are not executed, but skipped with an error instead.
//
// ::
//
//   Polarx.Crud::PrepareFind(stmt_id=1,...)
//   Polarx.Expect::Open([no_error]) // if a execute fails
//   Polarx.PreparedStmt::Execute(stmt_id=1,...)
//   Polarx.PreparedStmt::Execute(stmt_id=1,...)
//   Polarx.Expect::Close()
//   Polarx.PreparedStmt::Close(stmt_id=1,...)
//
// This basic mechanism is extended to carry a arbitrary set of conditions that are
// checked before executing message:
//
// ::
//
//   Polarx.Expect::Open([+no_error, +gtid_executed_contains = "...", +max_stmt_exec_time_ms = 10])
//
//   Polarx.Expect::Close()
//
// Expect blocks can be nested to increase/change the restrictions for a subset of the
// messages. At the end of the Expect block the previous restrictions are restored.
//
// ::
//
//   Polarx.Expect::Open([+no_error]) // if preparing the Find fails, don't try to close it
//   Polarx.Crud::PrepareFind(stmt_id=1,...)
//   Polarx.Expect::Open([+no_error]) // if a Execute fails, skip the rest of them and continue with Close
//   Polarx.PreparedStmt::Execute(stmt_id=1,...)
//   Polarx.PreparedStmt::Execute(stmt_id=1,...)
//   Polarx.Expect::Close()
//   Polarx.PreparedStmt::Close(stmt_id=1,...)
//   Polarx.Expect::Close()

// open an Expect block and set/unset the conditions that have to be fulfilled
//
// if any of the conditions fail, all enclosed messages will fail with
// a Polarx.Error message.
//
// :returns: :protobuf:msg:`Polarx::Ok` on success, :protobuf:msg:`Polarx::Error` on error
//
message Open {
  message Condition {
    enum ConditionOperation {
      // set the condition
      //
      // set, if not set
      // overwrite, if set
      EXPECT_OP_SET = 0;
      // unset the condition
      EXPECT_OP_UNSET = 1;
    };
    required uint32 condition_key = 1;
    optional bytes condition_value = 2;
    optional ConditionOperation op = 3 [ default = EXPECT_OP_SET ];
  };
  enum CtxOperation {
    // copy the operations from the parent Expect-block
    EXPECT_CTX_COPY_PREV = 0;
    // start with a empty set of operations
    EXPECT_CTX_EMPTY = 1;
  };
  optional CtxOperation op = 1 [ default = EXPECT_CTX_COPY_PREV ];
  repeated Condition cond = 2;
}

// close a Expect block
//
// closing a Expect block restores the state of the previous Expect block
// for the following messages
//
// :returns: :protobuf:msg:`Polarx::Ok` on success, :protobuf:msg:`Polarx::Error` on error
message Close {
}