From 014684fd5bee653ace75ff6d2d00b317e52a543a Mon Sep 17 00:00:00 2001
From: Jelte Fennema <github-tech@jeltef.nl>
Date: Tue, 25 Jun 2019 13:40:55 +0200
Subject: [PATCH 1/3] Add some helpers for Slice usage

---
 db_test.go | 37 ++++++++++++++++++++++++++++---------
 slice.go   |  8 +++++++-
 2 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/db_test.go b/db_test.go
index 3c0df0a1..4ccc7aa8 100644
--- a/db_test.go
+++ b/db_test.go
@@ -19,9 +19,8 @@ func TestDBCRUD(t *testing.T) {
 
 	var (
 		givenKey  = []byte("hello")
-		givenVal1 = []byte("world1")
-		givenVal2 = []byte("world2")
-		givenVal3 = []byte("world2")
+		givenVal1 = []byte("")
+		givenVal2 = []byte("world1")
 		wo        = NewDefaultWriteOptions()
 		ro        = NewDefaultReadOptions()
 	)
@@ -46,7 +45,7 @@ func TestDBCRUD(t *testing.T) {
 	v3, err := db.GetPinned(ro, givenKey)
 	defer v3.Destroy()
 	ensure.Nil(t, err)
-	ensure.DeepEqual(t, v3.Data(), givenVal3)
+	ensure.DeepEqual(t, v3.Data(), givenVal2)
 
 	// delete
 	ensure.Nil(t, db.Delete(wo, givenKey))
@@ -58,7 +57,7 @@ func TestDBCRUD(t *testing.T) {
 	v5, err := db.GetPinned(ro, givenKey)
 	defer v5.Destroy()
 	ensure.Nil(t, err)
-	ensure.Nil(t, v5.Data())
+	ensure.True(t, v5.Data() == nil)
 }
 
 func TestDBCRUDDBPaths(t *testing.T) {
@@ -75,12 +74,20 @@ func TestDBCRUDDBPaths(t *testing.T) {
 
 	var (
 		givenKey  = []byte("hello")
-		givenVal1 = []byte("world1")
-		givenVal2 = []byte("world2")
+		givenVal1 = []byte("")
+		givenVal2 = []byte("world1")
+		givenVal3 = []byte("world2")
 		wo        = NewDefaultWriteOptions()
 		ro        = NewDefaultReadOptions()
 	)
 
+	// retrieve before create
+	noexist, err := db.Get(ro, givenKey)
+	defer noexist.Free()
+	ensure.Nil(t, err)
+	ensure.False(t, noexist.Exists())
+	ensure.DeepEqual(t, noexist.Data(), []byte(nil))
+
 	// create
 	ensure.Nil(t, db.Put(wo, givenKey, givenVal1))
 
@@ -88,6 +95,7 @@ func TestDBCRUDDBPaths(t *testing.T) {
 	v1, err := db.Get(ro, givenKey)
 	defer v1.Free()
 	ensure.Nil(t, err)
+	ensure.True(t, v1.Exists())
 	ensure.DeepEqual(t, v1.Data(), givenVal1)
 
 	// update
@@ -95,13 +103,24 @@ func TestDBCRUDDBPaths(t *testing.T) {
 	v2, err := db.Get(ro, givenKey)
 	defer v2.Free()
 	ensure.Nil(t, err)
+	ensure.True(t, v2.Exists())
 	ensure.DeepEqual(t, v2.Data(), givenVal2)
 
+	// update
+	ensure.Nil(t, db.Put(wo, givenKey, givenVal3))
+	v3, err := db.Get(ro, givenKey)
+	defer v3.Free()
+	ensure.Nil(t, err)
+	ensure.True(t, v3.Exists())
+	ensure.DeepEqual(t, v3.Data(), givenVal3)
+
 	// delete
 	ensure.Nil(t, db.Delete(wo, givenKey))
-	v3, err := db.Get(ro, givenKey)
+	v4, err := db.Get(ro, givenKey)
+	defer v4.Free()
 	ensure.Nil(t, err)
-	ensure.True(t, v3.Data() == nil)
+	ensure.False(t, v4.Exists())
+	ensure.DeepEqual(t, v4.Data(), []byte(nil))
 }
 
 func newTestDB(t *testing.T, name string, applyOpts func(opts *Options)) *DB {
diff --git a/slice.go b/slice.go
index bcdc4c16..b450daa3 100644
--- a/slice.go
+++ b/slice.go
@@ -32,7 +32,8 @@ func StringToSlice(data string) *Slice {
 	return NewSlice(C.CString(data), C.size_t(len(data)))
 }
 
-// Data returns the data of the slice.
+// Data returns the data of the slice. If the key doesn't exist this will be a
+// nil slice.
 func (s *Slice) Data() []byte {
 	return charToByte(s.data, s.size)
 }
@@ -42,6 +43,11 @@ func (s *Slice) Size() int {
 	return int(s.size)
 }
 
+// Exists returns if the key exists
+func (s *Slice) Exists() bool {
+	return s.data != nil
+}
+
 // Free frees the slice data.
 func (s *Slice) Free() {
 	if !s.freed {

From 972a7642772c3b945969464fd9f6ec88f86863b8 Mon Sep 17 00:00:00 2001
From: Jelte Fennema <github-tech@jeltef.nl>
Date: Tue, 25 Jun 2019 13:43:22 +0200
Subject: [PATCH 2/3] Use xenial for travis

---
 .travis.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.travis.yml b/.travis.yml
index 79a7bb6c..e22ede6b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,3 +1,4 @@
+dist: xenial
 language: go
 go:
   - 1.11

From a72a84b502db7fbe63a08a41bc3f713eaf13aea3 Mon Sep 17 00:00:00 2001
From: Jelte Fennema <github-tech@jeltef.nl>
Date: Tue, 25 Jun 2019 13:46:59 +0200
Subject: [PATCH 3/3] Add -ldl needed apparently

---
 dynflag.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dynflag.go b/dynflag.go
index 81909317..501a4dd7 100644
--- a/dynflag.go
+++ b/dynflag.go
@@ -2,5 +2,5 @@
 
 package gorocksdb
 
-// #cgo LDFLAGS: -lrocksdb -lstdc++ -lm -lz -lbz2 -lsnappy
+// #cgo LDFLAGS: -lrocksdb -lstdc++ -lm -lz -lbz2 -lsnappy -ldl
 import "C"