/
persistence.go
94 lines (82 loc) · 2.14 KB
/
persistence.go
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package persistence
import (
"github.com/aws/aws-sdk-go/aws/session"
"github.com/fergusstrange/roundofbeer/api/errors"
"github.com/guregu/dynamo"
"time"
)
const roundOfBeer = "roundofbeer"
type Persistence interface {
CreateRoundTable()
CreateRound(round *Round)
FetchRound(roundID string) *Round
UpdateParticipantsAndCurrentCandidate(updatedRound *Round) *Round
}
type DynamoDBPersistence struct {
client *dynamo.DB
}
func NewDynamoDBPersistence() *DynamoDBPersistence {
return &DynamoDBPersistence{
client: newClient(),
}
}
type Round struct {
URL string `dynamo:"url,hash"`
Participants []Participant `dynamo:"participants"`
CurrentCandidate string `dynamo:"current_candidate"`
CreateDate time.Time `dynamo:"create_date"`
UpdateDate time.Time `dynamo:"update_date"`
}
type Participant struct {
UUID string `dynamo:"uuid"`
Name string `dynamo:"name"`
RoundCount int `dynamo:"round_count"`
}
func (db *DynamoDBPersistence) CreateRoundTable() {
tables, err := db.client.ListTables().All()
errors.LogFatal(err)
for _, table := range tables {
if table == roundOfBeer {
return
}
}
err = db.client.
CreateTable(roundOfBeer, Round{}).
Provision(3, 2).
Run()
errors.LogFatal(err)
}
func (db *DynamoDBPersistence) CreateRound(round *Round) {
err := db.client.
Table(roundOfBeer).
Put(round).
Run()
errors.LogFatal(err)
}
func (db *DynamoDBPersistence) FetchRound(roundID string) *Round {
round := new(Round)
err := db.client.
Table(roundOfBeer).
Get("url", roundID).
One(round)
if err != nil {
return nil
}
return round
}
func (db *DynamoDBPersistence) UpdateParticipantsAndCurrentCandidate(updatedRound *Round) *Round {
persistedRound := new(Round)
err := db.client.Table(roundOfBeer).
Update("url", updatedRound.URL).
Set("participants", updatedRound.Participants).
Set("current_candidate", updatedRound.CurrentCandidate).
Set("update_date", time.Now()).
Value(persistedRound)
errors.LogFatal(err)
return persistedRound
}
func newClient() *dynamo.DB {
newSession, err := session.NewSession()
errors.LogFatal(err)
return dynamo.New(newSession)
}