sample_vstream_client.go

/*
Copyright 2019 The Vitess Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package main

import (
        "context"
        "flag"
        "fmt"

        "vitess.io/vitess/go/mysql"
        "vitess.io/vitess/go/sqltypes"
        "vitess.io/vitess/go/vt/log"
        binlogdatapb "vitess.io/vitess/go/vt/proto/binlogdata"
        querypb "vitess.io/vitess/go/vt/proto/query"
        topodatapb "vitess.io/vitess/go/vt/proto/topodata"
        "vitess.io/vitess/go/vt/vtgate/vtgateconn"

        _ "vitess.io/vitess/go/vt/vtgate/grpcvtgateconn"
)

func main() {
        flag.Parse()
        ctx, cancel := context.WithCancel(context.Background())
        defer cancel()
        // Obtain binlog positions.
        var mpos []mysql.Position
        for _, tab := range []int{2, 3} {
                mysqlParams := &mysql.ConnParams{
                        Uname:      "vt_dba",
                        UnixSocket: fmt.Sprintf("/home/sougou/dev/demoroot/vt_0000000%d00/mysql.sock", tab),
                        Charset:    "utf8",
                }
                mconn, err := mysql.Connect(ctx, mysqlParams)
                if err != nil {
                        log.Exit(err)
                }

                pos, err := mconn.MasterPosition()
                if err != nil {
                        log.Exit(err)
                }
                mpos = append(mpos, pos)
                mconn.Close()
        }
        // Build the request.
        // You can add as many keyspace-shards as you want.
        vgtid := &binlogdatapb.VGtid{
                ShardGtids: []*binlogdatapb.ShardGtid{{
                        Keyspace: "customer",
                        Shard:    "-80",
                        Gtid:     fmt.Sprintf("%s/%s", mpos[0].GTIDSet.Flavor(), mpos[0]),
                }, {
                        Keyspace: "customer",
                        Shard:    "80-",
                        Gtid:     fmt.Sprintf("%s/%s", mpos[1].GTIDSet.Flavor(), mpos[1]),
                }},
        }
        filter := &binlogdatapb.Filter{
                Rules: []*binlogdatapb.Rule{{
                        // You can also filter specific tables or columns like this:
                        // Match:  "customer",
                        // Filter: "select cid, name from customer",
                        Match: "/.*/",
                }},
        }

        gconn, err := vtgateconn.Dial(ctx, "localhost:15991")
        if err != nil {
                log.Exit(err)
        }
        defer gconn.Close()
        reader, err := gconn.VStream(ctx, topodatapb.TabletType_MASTER, vgtid, filter)
        if err != nil {
                log.Exit(err)
        }
        tableFields := make(map[string][]*querypb.Field)
        for {
                events, err := reader.Recv()
                if err != nil {
                        log.Exit(err)
                }
                for _, event := range events {
                        switch event.Type {
                        case binlogdatapb.VEventType_FIELD:
                                // Update table fields. It's needed for processing ROW events.
                                tableFields[event.FieldEvent.TableName] = event.FieldEvent.Fields
                        case binlogdatapb.VEventType_ROW:
                                fmt.Printf("Row Event: %s\n", event.RowEvent.TableName)
                                for _, change := range event.RowEvent.RowChanges {
                                        fmt.Printf("  Befor: %v\n", toResult(tableFields[event.RowEvent.TableName], change.Before))
                                        fmt.Printf("  After: %v\n", toResult(tableFields[event.RowEvent.TableName], change.After))
                                }
                        case binlogdatapb.VEventType_VGTID:
                                // Remember vgtid here.
                        case binlogdatapb.VEventType_COMMIT:
                                // Save the remembered vgtid after processing COMMIT.
                                // The saved VGTID must be used to continue the stream if interrupted.
                        default:
                        }
                        if event.Type != binlogdatapb.VEventType_ROW {
                                fmt.Printf("%v\n", event)
                        }
                }
        }
}

func toResult(fields []*querypb.Field, row *querypb.Row) []sqltypes.Value {
        if row == nil {
                return nil
        }
        return sqltypes.Proto3ToResult(&querypb.QueryResult{
                Fields: fields,
                Rows:   []*querypb.Row{row},
        }).Rows[0]
}