Add Has() to exported API (extended API)

.drone.yml

@@ -12,11 +12,3 @@ steps:
     settings:
       token:
         from_secret: codecov-token
-
-  - name: notify
-    image: plugins/webhook
-    urls: https://msgbus.mills.io/ci.mills.io
-    when:
-      status:
-        - success
-        - failure

.goreleaser.yml

@@ -3,14 +3,14 @@ builds:
     binary: bitcask
     main: ./cmd/bitcask
     flags: -tags "static_build"
-    ldflags: -w -X .Version={{.Version}} -X .Commit={{.Commit}}
+    ldflags: -w -X github.com/prologic/bitcask/internal.Version={{.Version}} -X github.com/prologic/bitcask/internal.Commit={{.Commit}}
     env:
       - CGO_ENABLED=0
   - 
     binary: bitcaskd
     main: ./cmd/bitcaskd
     flags: -tags "static_build"
-    ldflags: -w -X .Version={{.Version}} -X .Commit={{.Commit}}
+    ldflags: -w -X github.com/prologic/bitcask/internal.Version={{.Version}} -X github.com/prologic/bitcask/internal.Commit={{.Commit}}
     env:
       - CGO_ENABLED=0
 sign:

Makefile

@@ -25,6 +25,7 @@ generate:
 
 install: build
 	@go install ./cmd/bitcask/...
+	@go install ./cmd/bitcaskd/...
 
 image:
 	@docker build -t prologic/bitcask .

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

@@ -1,7 +1,7 @@
 package bitcask
 
 import (
-	"fmt"
+	"errors"
 	"hash/crc32"
 	"io"
 	"io/ioutil"
@@ -15,6 +15,14 @@ import (
 	"github.com/prologic/bitcask/internal"
 )
 
+var (
+	ErrKeyNotFound    = errors.New("error: key not found")
+	ErrKeyTooLarge    = errors.New("error: key too large")
+	ErrValueTooLarge  = errors.New("error: value too large")
+	ErrChecksumFailed = errors.New("error: checksum failed")
+	ErrDatabaseLocked = errors.New("error: database locked")
+)
+
 type Bitcask struct {
 	*flock.Flock
 
@@ -49,7 +57,7 @@ func (b *Bitcask) Get(key string) ([]byte, error) {
 
 	item, ok := b.keydir.Get(key)
 	if !ok {
-		return nil, fmt.Errorf("error: key not found %s", key)
+		return nil, ErrKeyNotFound
 	}
 
 	if item.FileID == b.curr.FileID() {
@@ -65,18 +73,23 @@ func (b *Bitcask) Get(key string) ([]byte, error) {
 
 	checksum := crc32.ChecksumIEEE(e.Value)
 	if checksum != e.Checksum {
-		return nil, fmt.Errorf("error: checksum falied %s %d != %d", key, e.Checksum, checksum)
+		return nil, ErrChecksumFailed
 	}
 
 	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 fmt.Errorf("error: key too large %d > %d", len(key), b.config.MaxKeySize)
+		return ErrKeyTooLarge
 	}
 	if len(value) > b.config.MaxValueSize {
-		return fmt.Errorf("error: value too large %d > %d", len(value), b.config.MaxValueSize)
+		return ErrValueTooLarge
 	}
 
 	offset, err := b.put(key, value)
@@ -346,7 +359,7 @@ func Open(path string, options ...option) (*Bitcask, error) {
 
 	bitcask := &Bitcask{
 		Flock:     flock.New(filepath.Join(path, "lock")),
-		config:    NewDefaultConfig(),
+		config:    newDefaultConfig(),
 		path:      path,
 		curr:      curr,
 		keydir:    keydir,
@@ -369,7 +382,7 @@ func Open(path string, options ...option) (*Bitcask, error) {
 	}
 
 	if !locked {
-		return nil, fmt.Errorf("error: database locked %s", path)
+		return nil, ErrDatabaseLocked
 	}
 
 	return bitcask, nil

bitcask_test.go

@@ -40,12 +40,36 @@ 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)
 		_, err = db.Get("foo")
 		assert.Error(err)
-		assert.Equal("error: key not found foo", err.Error())
+		assert.Equal(ErrKeyNotFound, err)
 	})
 
 	t.Run("Sync", func(t *testing.T) {
@@ -92,7 +116,7 @@ func TestDeletedKeys(t *testing.T) {
 			assert.NoError(err)
 			_, err = db.Get("foo")
 			assert.Error(err)
-			assert.Equal("error: key not found foo", err.Error())
+			assert.Equal(ErrKeyNotFound, err)
 		})
 
 		t.Run("Sync", func(t *testing.T) {
@@ -120,7 +144,7 @@ func TestDeletedKeys(t *testing.T) {
 		t.Run("Get", func(t *testing.T) {
 			_, err = db.Get("foo")
 			assert.Error(err)
-			assert.Equal("error: key not found foo", err.Error())
+			assert.Equal(ErrKeyNotFound, err)
 		})
 
 		t.Run("Close", func(t *testing.T) {
@@ -148,7 +172,7 @@ func TestMaxKeySize(t *testing.T) {
 		value := []byte("foobar")
 		err = db.Put(key, value)
 		assert.Error(err)
-		assert.Equal("error: key too large 17 > 16", err.Error())
+		assert.Equal(ErrKeyTooLarge, err)
 	})
 }
 
@@ -170,11 +194,11 @@ func TestMaxValueSize(t *testing.T) {
 		value := []byte(strings.Repeat(" ", 17))
 		err = db.Put(key, value)
 		assert.Error(err)
-		assert.Equal("error: value too large 17 > 16", err.Error())
+		assert.Equal(ErrValueTooLarge, err)
 	})
 }
 
-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
@@ -387,7 +482,7 @@ func TestLocking(t *testing.T) {
 
 	_, err = Open(testdir)
 	assert.Error(err)
-	assert.Equal(fmt.Sprintf("error: database locked %s", testdir), err.Error())
+	assert.Equal(ErrDatabaseLocked, err)
 }
 
 type benchmarkTestCase struct {

options.go

@@ -17,7 +17,7 @@ type config struct {
 	MaxValueSize    int
 }
 
-func NewDefaultConfig() *config {
+func newDefaultConfig() *config {
 	return &config{
 		MaxDatafileSize: DefaultMaxDatafileSize,
 		MaxKeySize:      DefaultMaxKeySize,