vitess.io/vitess@v0.16.2/go/vt/binlog/tables_filter.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 binlog
    18  
    19  import (
    20  	"strings"
    21  
    22  	"vitess.io/vitess/go/vt/log"
    23  
    24  	binlogdatapb "vitess.io/vitess/go/vt/proto/binlogdata"
    25  	querypb "vitess.io/vitess/go/vt/proto/query"
    26  )
    27  
    28  const (
    29  	streamComment = "/* _stream "
    30  	space         = " "
    31  )
    32  
    33  // tablesFilterFunc returns a function that calls callback only if statements
    34  // in the transaction match the specified tables. The resulting function can be
    35  // passed into the Streamer: bls.Stream(file, pos, sendTransaction) ->
    36  // bls.Stream(file, pos, tablesFilterFunc(sendTransaction))
    37  func tablesFilterFunc(tables []string, callback func(*binlogdatapb.BinlogTransaction) error) sendTransactionFunc {
    38  	return func(eventToken *querypb.EventToken, statements []FullBinlogStatement) error {
    39  		matched := false
    40  		filtered := make([]*binlogdatapb.BinlogTransaction_Statement, 0, len(statements))
    41  		for _, statement := range statements {
    42  			switch statement.Statement.Category {
    43  			case binlogdatapb.BinlogTransaction_Statement_BL_SET:
    44  				filtered = append(filtered, statement.Statement)
    45  			case binlogdatapb.BinlogTransaction_Statement_BL_DDL:
    46  				log.Warningf("Not forwarding DDL: %s", statement.Statement.Sql)
    47  				continue
    48  			case binlogdatapb.BinlogTransaction_Statement_BL_INSERT,
    49  				binlogdatapb.BinlogTransaction_Statement_BL_UPDATE,
    50  				binlogdatapb.BinlogTransaction_Statement_BL_DELETE:
    51  				tableName := statement.Table
    52  				if tableName == "" {
    53  					// The statement doesn't
    54  					// contain the table name (SBR
    55  					// event), figure it out.
    56  					sql := string(statement.Statement.Sql)
    57  					tableIndex := strings.LastIndex(sql, streamComment)
    58  					if tableIndex == -1 {
    59  						updateStreamErrors.Add("TablesStream", 1)
    60  						log.Errorf("Error parsing table name: %s", sql)
    61  						continue
    62  					}
    63  					tableStart := tableIndex + len(streamComment)
    64  					tableEnd := strings.Index(sql[tableStart:], space)
    65  					if tableEnd == -1 {
    66  						updateStreamErrors.Add("TablesStream", 1)
    67  						log.Errorf("Error parsing table name: %s", sql)
    68  						continue
    69  					}
    70  					tableName = sql[tableStart : tableStart+tableEnd]
    71  				}
    72  				for _, t := range tables {
    73  					if t == tableName {
    74  						filtered = append(filtered, statement.Statement)
    75  						matched = true
    76  						break
    77  					}
    78  				}
    79  			case binlogdatapb.BinlogTransaction_Statement_BL_UNRECOGNIZED:
    80  				updateStreamErrors.Add("TablesStream", 1)
    81  				log.Errorf("Error parsing table name: %s", string(statement.Statement.Sql))
    82  				continue
    83  			}
    84  		}
    85  
    86  		trans := &binlogdatapb.BinlogTransaction{
    87  			EventToken: eventToken,
    88  		}
    89  		if matched {
    90  			trans.Statements = filtered
    91  		}
    92  		return callback(trans)
    93  	}
    94  }