96 lines
3.6 KiB
Go
96 lines
3.6 KiB
Go
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// Package dynamodbattribute provides marshaling and unmarshaling utilities to
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// convert between Go types and dynamodb.AttributeValues.
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//
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// These utilities allow you to marshal slices, maps, structs, and scalar values
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// to and from dynamodb.AttributeValue. These are useful when marshaling
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// Go value tyes to dynamodb.AttributeValue for DynamoDB requests, or
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// unmarshaling the dynamodb.AttributeValue back into a Go value type.
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//
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// AttributeValue Marshaling
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//
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// To marshal a Go type to a dynamodbAttributeValue you can use the Marshal
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// functions in the dynamodbattribute package. There are specialized versions
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// of these functions for collections of Attributevalue, such as maps and lists.
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//
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// The following example uses MarshalMap to convert the Record Go type to a
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// dynamodb.AttributeValue type and use the value to make a PutItem API request.
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//
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// type Record struct {
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// ID string
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// URLs []string
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// }
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//
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// //...
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//
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// r := Record{
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// ID: "ABC123",
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// URLs: []string{
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// "https://example.com/first/link",
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// "https://example.com/second/url",
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// },
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// }
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// av, err := dynamodbattribute.MarshalMap(r)
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// if err != nil {
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// panic(fmt.Sprintf("failed to DynamoDB marshal Record, %v", err))
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// }
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//
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// _, err := r.svc.PutItem(&dynamodb.PutItemInput{
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// TableName: aws.String(myTableName),
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// Item: av,
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// })
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// if err != nil {
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// panic(fmt.Sprintf("failed to put Record to DynamoDB, %v", err))
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// }
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//
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// AttributeValue Unmarshaling
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//
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// To unmarshal a dynamodb.AttributeValue to a Go type you can use the Unmarshal
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// functions in the dynamodbattribute package. There are specialized versions
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// of these functions for collections of Attributevalue, such as maps and lists.
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//
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// The following example will unmarshal the DynamoDB's Scan API operation. The
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// Items returned by the operation will be unmarshaled into the slice of Records
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// Go type.
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//
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// type Record struct {
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// ID string
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// URLs []string
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// }
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//
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// //...
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//
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// var records []Record
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//
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// // Use the ScanPages method to perform the scan with pagination. Use
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// // just Scan method to make the API call without pagination.
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// err := svc.ScanPages(&dynamodb.ScanInput{
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// TableName: aws.String(myTableName),
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// }, func(page *dynamodb.ScanOutput, last bool) bool {
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// recs := []Record{}
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//
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// err := dynamodbattribute.UnmarshalListOfMaps(page.Items, &recs)
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// if err != nil {
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// panic(fmt.Sprintf("failed to unmarshal Dynamodb Scan Items, %v", err))
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// }
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//
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// records = append(records, recs...)
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//
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// return true // keep paging
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// })
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//
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// The ConvertTo, ConvertToList, ConvertToMap, ConvertFrom, ConvertFromMap
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// and ConvertFromList methods have been deprecated. The Marshal and Unmarshal
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// functions should be used instead. The ConvertTo|From marshallers do not
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// support BinarySet, NumberSet, nor StringSets, and will incorrect marshal
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// binary data fields in structs as base64 strings.
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//
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// The Marshal and Unmarshal functions correct this behavior, and removes
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// the reliance on encoding.json. `json` struct tags are still supported. In
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// addition support for a new struct tag `dynamodbav` was added. Support for
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// the json.Marshaler and json.Unmarshaler interfaces have been removed and
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// replaced with have been replaced with dynamodbattribute.Marshaler and
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// dynamodbattribute.Unmarshaler interfaces.
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//
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// `time.Time` is marshaled as RFC3339 format.
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package dynamodbattribute
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