github.com/team-ide/go-dialect@v1.9.20/vitess/sqltypes/event_token.go (about)

     1  /*
     2  Copyright 2019 The Vitess Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package sqltypes
    18  
    19  import (
    20  	querypb "github.com/team-ide/go-dialect/vitess/query"
    21  )
    22  
    23  // EventTokenMinimum returns an event token that is guaranteed to
    24  // happen before both provided EventToken objects. Note it doesn't
    25  // parse the position, but rather only uses the timestamp. This is
    26  // meant to be used for EventToken objects coming from different
    27  // source shard.
    28  func EventTokenMinimum(ev1, ev2 *querypb.EventToken) *querypb.EventToken {
    29  	if ev1 == nil || ev2 == nil {
    30  		// One or the other is not set, we can't do anything.
    31  		return nil
    32  	}
    33  
    34  	if ev1.Timestamp < ev2.Timestamp {
    35  		return &querypb.EventToken{
    36  			Timestamp: ev1.Timestamp,
    37  		}
    38  	}
    39  	return &querypb.EventToken{
    40  		Timestamp: ev2.Timestamp,
    41  	}
    42  }