vspd/database/database.go
2020-05-14 14:04:14 +01:00

80 lines
2.0 KiB
Go

package database
import (
"encoding/binary"
"fmt"
"time"
bolt "go.etcd.io/bbolt"
)
// VspDatabase wraps an instance of bolt.DB and provides VSP specific
// convenience functions.
type VspDatabase struct {
db *bolt.DB
}
// The keys used in the database.
var (
// vspbkt is the main parent bucket of the VSP database. All values and
// other buckets are nested within it.
vspBktK = []byte("vspbkt")
// ticketbkt stores all tickets known by this VSP.
ticketBktK = []byte("ticketbkt")
// version is the current database version.
versionK = []byte("version")
)
// New initialises and returns a database. If no database file is found at the
// provided path, a new one will be created. Returns an open database which
// should always be closed after use.
func New(dbFile string) (*VspDatabase, error) {
db, err := bolt.Open(dbFile, 0600, &bolt.Options{Timeout: 1 * time.Second})
if err != nil {
return nil, fmt.Errorf("unable to open db file: %v", err)
}
err = createBuckets(db)
if err != nil {
return nil, err
}
return &VspDatabase{db: db}, nil
}
// Close releases all database resources. It will block waiting for any open
// transactions to finish before closing the database and returning.
func (vdb *VspDatabase) Close() error {
return vdb.db.Close()
}
// createBuckets creates all storage buckets of the VSP if they don't already
// exist.
func createBuckets(db *bolt.DB) error {
return db.Update(func(tx *bolt.Tx) error {
if tx.Bucket(vspBktK) == nil {
// Create parent bucket.
vspBkt, err := tx.CreateBucket(vspBktK)
if err != nil {
return fmt.Errorf("failed to create %s bucket: %v", string(vspBktK), err)
}
// Initialise with database version 1.
vbytes := make([]byte, 4)
binary.LittleEndian.PutUint32(vbytes, uint32(1))
err = vspBkt.Put(versionK, vbytes)
if err != nil {
return err
}
// Create ticket bucket.
_, err = vspBkt.CreateBucket(ticketBktK)
if err != nil {
return fmt.Errorf("failed to create %s bucket: %v", string(ticketBktK), err)
}
}
return nil
})
}