From dc3a88052c71d25626a166dc1bdb8057b73c179b Mon Sep 17 00:00:00 2001
From: Alex <alext@rtradetechnologies.com>
Date: Fri, 28 Jun 2019 16:26:33 -0700
Subject: [PATCH 1/2] datastore: actually enable prefix searching, and test for
 it

---
 datastore.go      |  4 ++--
 datastore_test.go | 21 ++++++++++++++++-----
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/datastore.go b/datastore.go
index 53a74ab..4e61fd9 100644
--- a/datastore.go
+++ b/datastore.go
@@ -88,7 +88,7 @@ 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 {
@@ -110,7 +110,7 @@ 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, _ := cursor.Seek(pref); k != nil && bytes.HasPrefix(k, pref); k, _ = cursor.Next() {
 			result := query.Result{}
 			key := datastore.NewKey(string(k))
 			result.Entry.Key = key.String()
diff --git a/datastore_test.go b/datastore_test.go
index 7d5d7c0..77df4e9 100644
--- a/datastore_test.go
+++ b/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)

From 134ec588411cfe404e7418330576f6d61e03de79 Mon Sep 17 00:00:00 2001
From: Alex <alext@rtradetechnologies.com>
Date: Fri, 28 Jun 2019 16:41:09 -0700
Subject: [PATCH 2/2] datastore: optimize non-keysOnly searches to avoid extra
 datastore calls

---
 datastore.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/datastore.go b/datastore.go
index 4e61fd9..2a90160 100644
--- a/datastore.go
+++ b/datastore.go
@@ -94,12 +94,12 @@ func (d *Datastore) Query(q query.Query) (query.Results, error) {
 	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); k != nil && 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 {