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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
/*
* Content before git sha 34fdeebefcbf183ed7f916f931aa0586fdaa1b40
* Copyright (c) 2016, The Gocql authors,
* provided under the BSD-3-Clause License.
* See the NOTICE file distributed with this work for additional information.
*/
package gocql_test
import (
"context"
"fmt"
"log"
"strconv"
"strings"
gocql "github.com/gocql/gocql"
)
// MyMarshaler implements Marshaler and Unmarshaler.
// It represents a version number stored as string.
type MyMarshaler struct {
major, minor, patch int
}
func (m MyMarshaler) MarshalCQL(info gocql.TypeInfo) ([]byte, error) {
return gocql.Marshal(info, fmt.Sprintf("%d.%d.%d", m.major, m.minor, m.patch))
}
func (m *MyMarshaler) UnmarshalCQL(info gocql.TypeInfo, data []byte) error {
var s string
err := gocql.Unmarshal(info, data, &s)
if err != nil {
return err
}
parts := strings.SplitN(s, ".", 3)
if len(parts) != 3 {
return fmt.Errorf("parse version %q: %d parts instead of 3", s, len(parts))
}
major, err := strconv.Atoi(parts[0])
if err != nil {
return fmt.Errorf("parse version %q major number: %v", s, err)
}
minor, err := strconv.Atoi(parts[1])
if err != nil {
return fmt.Errorf("parse version %q minor number: %v", s, err)
}
patch, err := strconv.Atoi(parts[2])
if err != nil {
return fmt.Errorf("parse version %q patch number: %v", s, err)
}
m.major = major
m.minor = minor
m.patch = patch
return nil
}
// Example_marshalerUnmarshaler demonstrates how to implement a Marshaler and Unmarshaler.
func Example_marshalerUnmarshaler() {
/* The example assumes the following CQL was used to setup the keyspace:
create keyspace example with replication = { 'class' : 'SimpleStrategy', 'replication_factor' : 1 };
create table example.my_marshaler_table(pk int, value text, PRIMARY KEY(pk));
*/
cluster := gocql.NewCluster("localhost:9042")
cluster.Keyspace = "example"
cluster.ProtoVersion = 4
session, err := cluster.CreateSession()
if err != nil {
log.Fatal(err)
}
defer session.Close()
ctx := context.Background()
value := MyMarshaler{
major: 1,
minor: 2,
patch: 3,
}
err = session.Query("INSERT INTO example.my_marshaler_table (pk, value) VALUES (?, ?)",
1, value).WithContext(ctx).Exec()
if err != nil {
log.Fatal(err)
}
var stringValue string
err = session.Query("SELECT value FROM example.my_marshaler_table WHERE pk = 1").WithContext(ctx).
Scan(&stringValue)
if err != nil {
log.Fatal(err)
}
fmt.Println(stringValue)
var unmarshaledValue MyMarshaler
err = session.Query("SELECT value FROM example.my_marshaler_table WHERE pk = 1").WithContext(ctx).
Scan(&unmarshaledValue)
if err != nil {
log.Fatal(err)
}
fmt.Println(unmarshaledValue)
// 1.2.3
// {1 2 3}
}
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