Unexpected behavior of Timestamp fraction precision

[bancek]

Amazon QLDB fails to insert a timestamp if fraction precision is 3 and milliseconds are divisible by 10.

Example:

type Entry struct {
	Time ion.Timestamp `ion:"time"`
}

millis := int64(1608218715340)
t := time.Unix(0, millis*1000000)
ts := ion.NewTimestampWithFractionalSeconds(t, ion.TimestampPrecisionNanosecond, ion.TimezoneUTC, 3)

entry := Entry{
	Time: ts,
}

_, err = driver.Execute(context.Background(), func(txn qldbdriver.Transaction) (interface{}, error) {
	return txn.Execute("INSERT INTO Test ?", entry)
})

The error from Amazon QLDB is

BadRequestException: Digests don't match
{
  RespMetadata: {
    StatusCode: 400,
    RequestID: "3GH3JFguR5O3LLcAwTQiiN"
  },
  Code_: "412",
  Message_: "Digests don't match"
}

Is this an expected behavior?

I've fixed this with a helper to calculate the fraction precision but I would expect the ion-go library to do automatically.

func getFractionPrecision(t time.Time) uint8 {
	millis := (t.UnixNano() / 1000000) % 1000
	fractionPrecision := uint8(3)

	if millis == 0 {
		fractionPrecision = 0
	} else {
		for millis > 0 && (millis%10) == 0 {
			millis /= 10
			fractionPrecision--
		}
	}

	return fractionPrecision
}

This is also a problem when using time.Time in a struct and setting it to time.Now().UTC(). It fails with same error Digests don't match.

Full example:

package main

import (
	"context"
	"time"

	"github.com/amzn/ion-go/ion"
	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/qldbsession"
	"github.com/awslabs/amazon-qldb-driver-go/qldbdriver"
)

func main() {
	awsSession := session.Must(session.NewSession(aws.NewConfig().WithRegion("us-east-1")))
	qldbSession := qldbsession.New(awsSession)

	driver, err := qldbdriver.New(
		"quick-start",
		qldbSession,
		func(options *qldbdriver.DriverOptions) {
			options.LoggerVerbosity = qldbdriver.LogInfo
		})
	if err != nil {
		panic(err)
	}
	defer driver.Shutdown(context.Background())

	_, err = driver.Execute(context.Background(), func(txn qldbdriver.Transaction) (interface{}, error) {
		_, err := txn.Execute("CREATE TABLE Test")
		if err != nil {
			return nil, err
		}
		return nil, nil
	})
	if err != nil {
		panic(err)
	}

	type Entry struct {
		Time ion.Timestamp `ion:"time"`
	}

	millis := int64(1608218715340)
	t := time.Unix(0, millis*1000000)
	ts := ion.NewTimestampWithFractionalSeconds(t, ion.TimestampPrecisionNanosecond, ion.TimezoneUTC, 3)

	entry := Entry{
		Time: ts,
	}

	_, err = driver.Execute(context.Background(), func(txn qldbdriver.Transaction) (interface{}, error) {
		return txn.Execute("INSERT INTO Test ?", entry)
	})
	if err != nil {
		panic(err)
	}
}

Versions:

github.com/amzn/ion-go v1.1.0
github.com/amzn/ion-hash-go v1.1.0
github.com/aws/aws-sdk-go v1.36.8
github.com/awslabs/amazon-qldb-driver-go v1.0.1

[byronlin13]

Hi @bancek ,

We have released a new version of the Go driver that fixes this bug.

[bancek]

Thanks 🎉