Add Has() to exported API (extended API)

README.md

@@ -6,13 +6,13 @@
 [![GoDoc](https://godoc.org/github.com/prologic/bitcask?status.svg)](https://godoc.org/github.com/prologic/bitcask) 
 [![Sourcegraph](https://sourcegraph.com/github.com/prologic/bitcask/-/badge.svg)](https://sourcegraph.com/github.com/prologic/bitcask?badge)
 
-A Bitcask (LSM+WAL) Key/Value Store written in Go.
+A high performance Key/Value store written in [Go](https://golang.org) with a predictable read/write performance and high throughput. Uses a [Bitcask](https://en.wikipedia.org/wiki/Bitcask) on-disk layout (LSM+WAL) similar to [Riak](https://riak.com/).
 
 ## Features
 
-* Embeddable
-* Builtin CLI
-* Builtin Redis-compatible server
+* Embeddable (`import "github.com/prologic/bitcask"`)
+* Builtin CLI (`bitcask`)
+* Builtin Redis-compatible server (`bitcaskd`)
 * Predictable read/write performance
 * Low latecny
 * High throughput (See: [Performance](README.md#Performance)
@@ -34,16 +34,13 @@ $ go get github.com/prologic/bitcask
 ```#!go
 package main
 
-import (
-    "log"
-
-    "github.com/prologic/bitcask"
-)
+import "github.com/prologic/bitcask"
 
 func main() {
     db, _ := bitcask.Open("/tmp/db")
+    defer db.Close()
     db.Set("Hello", []byte("World"))
-    db.Close()
+    val, _ := db.Get("hello")
 }
 ```
 

bitcask.go

@@ -79,6 +79,11 @@ func (b *Bitcask) Get(key string) ([]byte, error) {
 	return e.Value, nil
 }
 
+func (b *Bitcask) Has(key string) bool {
+	_, ok := b.keydir.Get(key)
+	return ok
+}
+
 func (b *Bitcask) Put(key string, value []byte) error {
 	if len(key) > b.config.MaxKeySize {
 		return ErrKeyTooLarge

bitcask_test.go

@@ -40,6 +40,30 @@ func TestAll(t *testing.T) {
 		assert.Equal([]byte("bar"), val)
 	})
 
+	t.Run("Has", func(t *testing.T) {
+		assert.True(db.Has("foo"))
+	})
+
+	t.Run("Fold", func(t *testing.T) {
+		var (
+			keys   []string
+			values [][]byte
+		)
+
+		err := db.Fold(func(key string) error {
+			value, err := db.Get(key)
+			if err != nil {
+				return err
+			}
+			keys = append(keys, key)
+			values = append(values, value)
+			return nil
+		})
+		assert.NoError(err)
+		assert.Equal([]string{"foo"}, keys)
+		assert.Equal([][]byte{[]byte("bar")}, values)
+	})
+
 	t.Run("Delete", func(t *testing.T) {
 		err := db.Delete("foo")
 		assert.NoError(err)
@@ -174,7 +198,7 @@ func TestMaxValueSize(t *testing.T) {
 	})
 }
 
-func TestMerge(t *testing.T) {
+func TestOpenMerge(t *testing.T) {
 	assert := assert.New(t)
 
 	testdir, err := ioutil.TempDir("", "bitcask")
@@ -187,7 +211,7 @@ func TestMerge(t *testing.T) {
 		)
 
 		t.Run("Open", func(t *testing.T) {
-			db, err = Open(testdir, WithMaxDatafileSize(1024))
+			db, err = Open(testdir, WithMaxDatafileSize(32))
 			assert.NoError(err)
 		})
 
@@ -245,6 +269,77 @@ func TestMerge(t *testing.T) {
 	})
 }
 
+func TestMergeOpen(t *testing.T) {
+	var (
+		db  *Bitcask
+		err error
+	)
+
+	assert := assert.New(t)
+
+	testdir, err := ioutil.TempDir("", "bitcask")
+	assert.NoError(err)
+
+	t.Run("Setup", func(t *testing.T) {
+		t.Run("Open", func(t *testing.T) {
+			db, err = Open(testdir, WithMaxDatafileSize(32))
+			assert.NoError(err)
+		})
+
+		t.Run("Put", func(t *testing.T) {
+			for i := 0; i < 1024; i++ {
+				err = db.Put(string(i), []byte(strings.Repeat(" ", 1024)))
+				assert.NoError(err)
+			}
+		})
+
+		t.Run("Get", func(t *testing.T) {
+			for i := 0; i < 32; i++ {
+				err = db.Put(string(i), []byte(strings.Repeat(" ", 1024)))
+				assert.NoError(err)
+				val, err := db.Get(string(i))
+				assert.NoError(err)
+				assert.Equal([]byte(strings.Repeat(" ", 1024)), val)
+			}
+		})
+
+		t.Run("Sync", func(t *testing.T) {
+			err = db.Sync()
+			assert.NoError(err)
+		})
+
+		t.Run("Close", func(t *testing.T) {
+			err = db.Close()
+			assert.NoError(err)
+		})
+	})
+
+	t.Run("Merge", func(t *testing.T) {
+		t.Run("Merge", func(t *testing.T) {
+			err = Merge(testdir, true)
+			assert.NoError(err)
+		})
+
+		t.Run("Open", func(t *testing.T) {
+			db, err = Open(testdir)
+			assert.NoError(err)
+		})
+
+		t.Run("Get", func(t *testing.T) {
+			for i := 0; i < 32; i++ {
+				val, err := db.Get(string(i))
+				assert.NoError(err)
+				assert.Equal([]byte(strings.Repeat(" ", 1024)), val)
+			}
+		})
+
+		t.Run("Close", func(t *testing.T) {
+			err = db.Close()
+			assert.NoError(err)
+		})
+	})
+}
+
 func TestConcurrent(t *testing.T) {
 	var (
 		db  *Bitcask