From 92a7b2359067b7333700645768a7010b1b012066 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=B6khan=20=C3=96zelo=C4=9Flu?= <gozeloglu@gmail.com>
Date: Fri, 29 Oct 2021 14:43:53 +0300
Subject: [PATCH] Add Keys function
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Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Keys() method added for listing stored keys in database. Usage added in README and pkg/main.go.

Signed-off-by: Gökhan Özeloğlu <gozeloglu@gmail.com>
---
 README.md           |  7 ++++-
 example/pkg/main.go |  5 ++++
 keys.go             | 14 +++++++++
 keys_test.go        | 69 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 94 insertions(+), 1 deletion(-)
 create mode 100644 keys.go
 create mode 100644 keys_test.go

diff --git a/README.md b/README.md
index bd4e3c9..354b713 100644
--- a/README.md
+++ b/README.md
@@ -104,7 +104,12 @@ func main() {
 		log.Fatalf(err.Error())
 	}
 	fmt.Printf("key name changed: %v1\n", ok)
-	
+
+	keys := db.Keys()
+	for _, k := range keys {
+		fmt.Println(k)
+	}
+
 	err = db.Close() // Call while closing the database.
 	if err != nil {
 		log.Fatalf(err.Error())
diff --git a/example/pkg/main.go b/example/pkg/main.go
index 0b8894f..2979400 100644
--- a/example/pkg/main.go
+++ b/example/pkg/main.go
@@ -51,6 +51,11 @@ func main() {
 	}
 	fmt.Printf("key name changed: %v1\n", ok)
 
+	keys := db.Keys()
+	for _, k := range keys {
+		fmt.Println(k)
+	}
+
 	err = db.Close()
 	if err != nil {
 		log.Fatalf(err.Error())
diff --git a/keys.go b/keys.go
new file mode 100644
index 0000000..aef1bbf
--- /dev/null
+++ b/keys.go
@@ -0,0 +1,14 @@
+package kvs
+
+// Keys list the stored keys in a slice. If db is empty, empty slice is returned.
+func (k *Kvs) Keys() []string {
+	k.mu.Lock()
+	defer k.mu.Unlock()
+	var keys []string
+
+	for key := range k.kv {
+		keys = append(keys, key)
+	}
+
+	return keys
+}
diff --git a/keys_test.go b/keys_test.go
new file mode 100644
index 0000000..f525e57
--- /dev/null
+++ b/keys_test.go
@@ -0,0 +1,69 @@
+package kvs
+
+import (
+	"os"
+	"testing"
+	"time"
+)
+
+func TestKvs_Keys(t *testing.T) {
+	db, err := open(t.Name(), "", 2*time.Minute)
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("db created.")
+
+	pairs := []string{"foo", "1", "bar", "2", "fizz", "3", "buzz", "4"}
+	for i := 0; i < len(pairs); i += 2 {
+		db.Set(pairs[i], pairs[i+1])
+	}
+	t.Logf("key-value pairs are set.")
+
+	keys := db.Keys()
+	if len(keys) != len(pairs)/2 {
+		t.Errorf("Fetched keys are wrong. pairs len is %d, "+
+			"fetched len is %d.", len(pairs)/2, len(keys))
+	}
+	for _, k := range keys {
+		t.Logf(k)
+	}
+
+	err = db.Close()
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("db closed.")
+
+	err = os.RemoveAll(db.dir)
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("temp db removed.")
+}
+
+func TestKvs_EmptyKeys(t *testing.T) {
+	db, err := open(t.Name(), "", 2*time.Minute)
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("db created.")
+
+	keys := db.Keys()
+	if len(keys) != 0 {
+		t.Errorf("Fetched keys are wrong. pairs len is %d, "+
+			"fetched len is %d.", 0, len(keys))
+	}
+	t.Logf("Empty slice: %d", len(keys))
+
+	err = db.Close()
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("db closed.")
+
+	err = os.RemoveAll(db.dir)
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	t.Logf("temp db removed.")
+}