harness-drone/datastore/builtin/util.go
2015-05-05 20:22:02 -07:00

115 lines
2.3 KiB
Go

package builtin
import (
"bytes"
"github.com/boltdb/bolt"
//"github.com/youtube/vitess/go/bson"
"encoding/gob"
)
func encode(v interface{}) ([]byte, error) {
var buf bytes.Buffer
var err = gob.NewEncoder(&buf).Encode(v)
return buf.Bytes(), err
//return bson.Marshal(v)
}
func decode(raw []byte, v interface{}) error {
var buf bytes.Buffer
buf.Write(raw)
var err = gob.NewDecoder(&buf).Decode(v)
return err
//return bson.Unmarshal(raw, v)
}
func get(t *bolt.Tx, bucket, key []byte, v interface{}) error {
raw := t.Bucket(bucket).Get(key)
if raw == nil {
return ErrKeyNotFound
}
return decode(raw, v)
}
func raw(t *bolt.Tx, bucket, key []byte) ([]byte, error) {
raw := t.Bucket(bucket).Get(key)
if raw == nil {
return nil, ErrKeyNotFound
}
return raw, nil
}
func update(t *bolt.Tx, bucket, key []byte, v interface{}) error {
raw, err := encode(v)
if err != nil {
t.Rollback()
return err
}
return t.Bucket(bucket).Put(key, raw)
}
func insert(t *bolt.Tx, bucket, key []byte, v interface{}) error {
raw, err := encode(v)
if err != nil {
t.Rollback()
return err
}
// verify the key does not already exists
// in the bucket. If exists, fail
if t.Bucket(bucket).Get(key) != nil {
return ErrKeyExists
}
return t.Bucket(bucket).Put(key, raw)
}
func delete(t *bolt.Tx, bucket, key []byte) error {
return t.Bucket(bucket).Delete(key)
}
func push(t *bolt.Tx, bucket, index, value []byte) error {
var keys [][]byte
err := get(t, bucket, index, &keys)
if err != nil && err != ErrKeyNotFound {
return err
}
// we shouldn't add a key that already exists
for _, key := range keys {
if bytes.Equal(key, value) {
return nil
}
}
keys = append(keys, value)
return update(t, bucket, index, &keys)
}
func splice(t *bolt.Tx, bucket, index, value []byte) error {
var keys [][]byte
err := get(t, bucket, index, &keys)
if err != nil && err != ErrKeyNotFound {
return err
}
for i, key := range keys {
if bytes.Equal(key, value) {
keys = keys[:i+copy(keys[i:], keys[i+1:])]
break
}
}
return update(t, bucket, index, &keys)
}
func deleteWithPrefix(t *bolt.Tx, bucket, prefix []byte) error {
var err error
c := t.Bucket(bucket).Cursor()
for k, _ := c.Seek(prefix); bytes.HasPrefix(k, prefix); k, _ = c.Next() {
err = c.Delete()
if err != nil {
break
}
}
// only error here is if our Tx is read-only
return err
}