Merge pull request #7 from RTradeLtd/query/fix#prefix

Enable Proper Prefix Searching

datastore.go

@@ -88,18 +88,18 @@ func (d *Datastore) GetSize(key datastore.Key) (int, error) {
 // Query performs a complex search query on the underlying datastore
 // For more information see :
 // https://github.com/ipfs/go-datastore/blob/aa9190c18f1576be98e974359fd08c64ca0b5a94/examples/fs.go#L96
-// https://github.com/boltdb/bolt/issues/518#issuecomment-187211346
+// https://github.com/etcd-io/bbolt#prefix-scans
 func (d *Datastore) Query(q query.Query) (query.Results, error) {
  resBuilder := query.NewResultBuilder(q)
  if err := d.db.View(func(tx *bbolt.Tx) error {
  cursor := tx.Bucket(d.bucket).Cursor()
  if q.Prefix == "" {
- for k, _ := cursor.First(); k != nil; k, _ = cursor.Next() {
+ for k, v := cursor.First(); k != nil; k, v = cursor.Next() {
  result := query.Result{}
  key := datastore.NewKey(string(k))
  result.Entry.Key = key.String()
  if !q.KeysOnly {
- result.Entry.Value, result.Error = d.Get(key)
+ result.Entry.Value = v
  }
  select {
  case resBuilder.Output <- result:
@@ -110,12 +110,12 @@ func (d *Datastore) Query(q query.Query) (query.Results, error) {
  return nil
  }
  pref := []byte(q.Prefix)
- for k, _ := cursor.Seek(pref); bytes.HasPrefix(k, pref); k, _ = cursor.Next() {
+ for k, v := cursor.Seek(pref); k != nil && bytes.HasPrefix(k, pref); k, v = cursor.Next() {
  result := query.Result{}
  key := datastore.NewKey(string(k))
  result.Entry.Key = key.String()
  if !q.KeysOnly {
- result.Entry.Value, result.Error = d.Get(key)
+ result.Entry.Value = v
  }
  // initiate a non-blocking channel send
  select {

datastore_test.go

@@ -1,7 +1,6 @@
 package dsbbolt
 
 import (
- "fmt"
  "testing"
 
  "reflect"
@@ -71,8 +70,8 @@ func Test_Datastore(t *testing.T) {
  if err != nil {
  t.Fatal(err)
  }
- for _, v := range res {
- fmt.Printf("%+v\n", v)
+ if len(res) == 0 {
+ t.Fatal("bad number of results")
  }
  // test a query where we dont specify a search key
  rs, err = ds.Query(query.Query{})
@@ -83,8 +82,20 @@ func Test_Datastore(t *testing.T) {
  if err != nil {
  t.Fatal(err)
  }
- for _, v := range res {
- fmt.Printf("%+v\n", v)
+ if len(res) == 0 {
+ t.Fatal("bad number of results")
+ }
+ // test a query where we specify a partial prefix
+ rs, err = ds.Query(query.Query{Prefix: "/kek"})
+ if err != nil {
+ t.Fatal(err)
+ }
+ res, err = rs.Rest()
+ if err != nil {
+ t.Fatal(err)
+ }
+ if len(res) == 0 {
+ t.Fatal("bad number of results")
  }
  if err := ds.Delete(key); err != nil {
  t.Fatal(err)