155 lines
3.3 KiB
Go
155 lines
3.3 KiB
Go
package index
|
|
|
|
import (
|
|
"bytes"
|
|
|
|
"github.com/asdine/storm/internal"
|
|
"github.com/boltdb/bolt"
|
|
)
|
|
|
|
// NewUniqueIndex loads a UniqueIndex
|
|
func NewUniqueIndex(parent *bolt.Bucket, indexName []byte) (*UniqueIndex, error) {
|
|
var err error
|
|
b := parent.Bucket(indexName)
|
|
if b == nil {
|
|
if !parent.Writable() {
|
|
return nil, ErrNotFound
|
|
}
|
|
b, err = parent.CreateBucket(indexName)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
|
|
return &UniqueIndex{
|
|
IndexBucket: b,
|
|
Parent: parent,
|
|
}, nil
|
|
}
|
|
|
|
// UniqueIndex is an index that references unique values and the corresponding ID.
|
|
type UniqueIndex struct {
|
|
Parent *bolt.Bucket
|
|
IndexBucket *bolt.Bucket
|
|
}
|
|
|
|
// Add a value to the unique index
|
|
func (idx *UniqueIndex) Add(value []byte, targetID []byte) error {
|
|
if value == nil || len(value) == 0 {
|
|
return ErrNilParam
|
|
}
|
|
if targetID == nil || len(targetID) == 0 {
|
|
return ErrNilParam
|
|
}
|
|
|
|
exists := idx.IndexBucket.Get(value)
|
|
if exists != nil {
|
|
if bytes.Equal(exists, targetID) {
|
|
return nil
|
|
}
|
|
return ErrAlreadyExists
|
|
}
|
|
|
|
return idx.IndexBucket.Put(value, targetID)
|
|
}
|
|
|
|
// Remove a value from the unique index
|
|
func (idx *UniqueIndex) Remove(value []byte) error {
|
|
return idx.IndexBucket.Delete(value)
|
|
}
|
|
|
|
// RemoveID removes an ID from the unique index
|
|
func (idx *UniqueIndex) RemoveID(id []byte) error {
|
|
c := idx.IndexBucket.Cursor()
|
|
|
|
for val, ident := c.First(); val != nil; val, ident = c.Next() {
|
|
if bytes.Equal(ident, id) {
|
|
return idx.Remove(val)
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Get the id corresponding to the given value
|
|
func (idx *UniqueIndex) Get(value []byte) []byte {
|
|
return idx.IndexBucket.Get(value)
|
|
}
|
|
|
|
// All returns all the ids corresponding to the given value
|
|
func (idx *UniqueIndex) All(value []byte, opts *Options) ([][]byte, error) {
|
|
id := idx.IndexBucket.Get(value)
|
|
if id != nil {
|
|
return [][]byte{id}, nil
|
|
}
|
|
|
|
return nil, nil
|
|
}
|
|
|
|
// AllRecords returns all the IDs of this index
|
|
func (idx *UniqueIndex) AllRecords(opts *Options) ([][]byte, error) {
|
|
var list [][]byte
|
|
|
|
c := internal.Cursor{C: idx.IndexBucket.Cursor(), Reverse: opts != nil && opts.Reverse}
|
|
|
|
for val, ident := c.First(); val != nil; val, ident = c.Next() {
|
|
if opts != nil && opts.Skip > 0 {
|
|
opts.Skip--
|
|
continue
|
|
}
|
|
|
|
if opts != nil && opts.Limit == 0 {
|
|
break
|
|
}
|
|
|
|
if opts != nil && opts.Limit > 0 {
|
|
opts.Limit--
|
|
}
|
|
|
|
list = append(list, ident)
|
|
}
|
|
return list, nil
|
|
}
|
|
|
|
// Range returns the ids corresponding to the given range of values
|
|
func (idx *UniqueIndex) Range(min []byte, max []byte, opts *Options) ([][]byte, error) {
|
|
var list [][]byte
|
|
|
|
c := internal.RangeCursor{
|
|
C: idx.IndexBucket.Cursor(),
|
|
Reverse: opts != nil && opts.Reverse,
|
|
Min: min,
|
|
Max: max,
|
|
CompareFn: func(val, limit []byte) int {
|
|
return bytes.Compare(val, limit)
|
|
},
|
|
}
|
|
|
|
for val, ident := c.First(); val != nil && c.Continue(val); val, ident = c.Next() {
|
|
if opts != nil && opts.Skip > 0 {
|
|
opts.Skip--
|
|
continue
|
|
}
|
|
|
|
if opts != nil && opts.Limit == 0 {
|
|
break
|
|
}
|
|
|
|
if opts != nil && opts.Limit > 0 {
|
|
opts.Limit--
|
|
}
|
|
|
|
list = append(list, ident)
|
|
}
|
|
return list, nil
|
|
}
|
|
|
|
// first returns the first ID of this index
|
|
func (idx *UniqueIndex) first() []byte {
|
|
c := idx.IndexBucket.Cursor()
|
|
|
|
for val, ident := c.First(); val != nil; val, ident = c.Next() {
|
|
return ident
|
|
}
|
|
return nil
|
|
}
|