/
task_registerer.go
103 lines (92 loc) · 3.95 KB
/
task_registerer.go
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package dynamo
import (
"fmt"
"strconv"
"time"
"github.com/artii15/termination-detector/pkg/task"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/awserr"
"github.com/aws/aws-sdk-go/service/dynamodb"
"github.com/aws/aws-sdk-go/service/dynamodb/dynamodbiface"
)
const (
decimalBase = 10
taskTTLValuePlaceholder = ":ttl"
taskExpirationTimeValuePlaceholder = ":expirationTime"
)
var (
registerTaskConditionExpr = fmt.Sprintf("attribute_not_exists(%s) and attribute_not_exists(%s)",
ProcessIDAttrAlias, taskIDAttrAlias)
registerTaskUpdateExpr = fmt.Sprintf(`SET %s = %s, %s = %s, %s = %s, %s = %s`,
taskExpirationTimeAttrAlias, taskExpirationTimeValuePlaceholder, taskStateAttrAlias, taskStateCreatedValuePlaceholder,
taskTTLAttrAlias, taskTTLValuePlaceholder, taskBadStateEnterTimeAttrAlias, taskBadStateEnterTimeValuePlaceholder)
)
type currentDateGetter interface {
GetCurrentDate() time.Time
}
type TaskRegisterer struct {
dynamoAPI dynamodbiface.DynamoDBAPI
tasksTableName string
currentDateGetter currentDateGetter
tasksStoringDuration time.Duration
}
func NewTaskRegisterer(dynamoAPI dynamodbiface.DynamoDBAPI, tasksTableName string,
currentDateGetter currentDateGetter, tasksStoringDuration time.Duration) *TaskRegisterer {
return &TaskRegisterer{
dynamoAPI: dynamoAPI,
tasksTableName: tasksTableName,
currentDateGetter: currentDateGetter,
tasksStoringDuration: tasksStoringDuration,
}
}
func (registerer *TaskRegisterer) Register(registrationData task.RegistrationData) (task.RegistrationResult, error) {
if err := registerer.saveTask(registrationData); err != nil {
if awsErr, isAWSErr := err.(awserr.Error); isAWSErr && awsErr.Code() == dynamodb.ErrCodeConditionalCheckFailedException {
return task.RegistrationResultAlreadyRegistered, nil
}
return "", err
}
return task.RegistrationResultCreated, nil
}
func (registerer *TaskRegisterer) saveTask(registrationData task.RegistrationData) error {
updateItemInput := BuildRegisterTaskUpdateItemInput(registerer.tasksTableName, TaskToRegister{
CreationTime: registerer.currentDateGetter.GetCurrentDate(),
StoringDuration: registerer.tasksStoringDuration,
RegistrationData: registrationData,
})
_, err := registerer.dynamoAPI.UpdateItem(updateItemInput)
return err
}
type TaskToRegister struct {
CreationTime time.Time
StoringDuration time.Duration
RegistrationData task.RegistrationData
}
func BuildRegisterTaskUpdateItemInput(tableName string, taskToRegister TaskToRegister) *dynamodb.UpdateItemInput {
ttl := taskToRegister.CreationTime.Add(taskToRegister.StoringDuration).UTC().Unix()
ttlString := strconv.FormatInt(ttl, decimalBase)
expirationTimeString := taskToRegister.RegistrationData.ExpirationTime.Format(time.RFC3339)
return &dynamodb.UpdateItemInput{
ConditionExpression: ®isterTaskConditionExpr,
ExpressionAttributeNames: map[string]*string{
ProcessIDAttrAlias: aws.String(ProcessIDAttrName),
taskIDAttrAlias: aws.String(TaskIDAttrName),
taskStateAttrAlias: aws.String(TaskStateAttrName),
taskExpirationTimeAttrAlias: aws.String(taskExpirationTimeAttrName),
taskTTLAttrAlias: aws.String(taskTTLAttributeName),
taskBadStateEnterTimeAttrAlias: aws.String(TaskBadStateEnterTimeAttrName),
},
ExpressionAttributeValues: map[string]*dynamodb.AttributeValue{
taskStateCreatedValuePlaceholder: {S: aws.String(string(task.StateCreated))},
taskTTLValuePlaceholder: {N: &ttlString},
taskExpirationTimeValuePlaceholder: {S: &expirationTimeString},
taskBadStateEnterTimeValuePlaceholder: {S: &expirationTimeString},
},
UpdateExpression: ®isterTaskUpdateExpr,
TableName: &tableName,
Key: map[string]*dynamodb.AttributeValue{
ProcessIDAttrName: {S: &taskToRegister.RegistrationData.ID.ProcessID},
TaskIDAttrName: {S: &taskToRegister.RegistrationData.ID.TaskID},
},
}
}