Improved error messages

bitcask.go

@@ -1,7 +1,7 @@
 package bitcask
 
 import (
-	"errors"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
@@ -9,15 +9,8 @@ import (
 	"strings"
 	"time"
 
-	"github.com/derekparker/trie"
 	"github.com/gofrs/flock"
-)
-
-var (
-	ErrKeyNotFound    = errors.New("error: key not found")
-	ErrKeyTooLarge    = errors.New("error: key too large")
-	ErrValueTooLarge  = errors.New("error: value too large")
-	ErrDatabaseLocked = errors.New("error: database locked")
+	"github.com/prologic/trie"
 )
 
 type Bitcask struct {
@@ -54,7 +47,7 @@ func (b *Bitcask) Get(key string) ([]byte, error) {
 
 	item, ok := b.keydir.Get(key)
 	if !ok {
-		return nil, ErrKeyNotFound
+		return nil, fmt.Errorf("error: key not found %s", key)
 	}
 
 	if item.FileID == b.curr.id {
@@ -73,10 +66,10 @@ func (b *Bitcask) Get(key string) ([]byte, error) {
 
 func (b *Bitcask) Put(key string, value []byte) error {
 	if len(key) > b.opts.MaxKeySize {
-		return ErrKeyTooLarge
+		return fmt.Errorf("error: key too large %d > %d", len(key), b.opts.MaxKeySize)
 	}
 	if len(value) > b.opts.MaxValueSize {
-		return ErrValueTooLarge
+		return fmt.Errorf("error: value too large %d > %d", len(value), b.opts.MaxValueSize)
 	}
 
 	index, err := b.put(key, value)
@@ -365,7 +358,7 @@ func Open(path string, options ...func(*Bitcask) error) (*Bitcask, error) {
 	}
 
 	if !locked {
-		return nil, ErrDatabaseLocked
+		return nil, fmt.Errorf("error: database locked %s", path)
 	}
 
 	return bitcask, nil

bitcask_test.go

@@ -45,7 +45,7 @@ func TestAll(t *testing.T) {
 		assert.NoError(err)
 		_, err = db.Get("foo")
 		assert.Error(err)
-		assert.Equal(err.Error(), "error: key not found")
+		assert.Equal("error: key not found foo", err.Error())
 	})
 
 	t.Run("Sync", func(t *testing.T) {
@@ -92,7 +92,7 @@ func TestDeletedKeys(t *testing.T) {
 			assert.NoError(err)
 			_, err = db.Get("foo")
 			assert.Error(err)
-			assert.Equal("error: key not found", err.Error())
+			assert.Equal("error: key not found foo", err.Error())
 		})
 
 		t.Run("Sync", func(t *testing.T) {
@@ -120,7 +120,7 @@ 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", err.Error())
+			assert.Equal("error: key not found foo", err.Error())
 		})
 
 		t.Run("Close", func(t *testing.T) {
@@ -138,19 +138,17 @@ func TestMaxKeySize(t *testing.T) {
 
 	var db *Bitcask
 
-	size := 16
-
 	t.Run("Open", func(t *testing.T) {
-		db, err = Open(testdir, WithMaxKeySize(size))
+		db, err = Open(testdir, WithMaxKeySize(16))
 		assert.NoError(err)
 	})
 
 	t.Run("Put", func(t *testing.T) {
-		key := strings.Repeat(" ", size+1)
+		key := strings.Repeat(" ", 17)
 		value := []byte("foobar")
 		err = db.Put(key, value)
 		assert.Error(err)
-		assert.Equal("error: key too large", err.Error())
+		assert.Equal("error: key too large 17 > 16", err.Error())
 	})
 }
 
@@ -162,19 +160,17 @@ func TestMaxValueSize(t *testing.T) {
 
 	var db *Bitcask
 
-	size := 16
-
 	t.Run("Open", func(t *testing.T) {
-		db, err = Open(testdir, WithMaxValueSize(size))
+		db, err = Open(testdir, WithMaxValueSize(16))
 		assert.NoError(err)
 	})
 
 	t.Run("Put", func(t *testing.T) {
 		key := "foo"
-		value := []byte(strings.Repeat(" ", size+1))
+		value := []byte(strings.Repeat(" ", 17))
 		err = db.Put(key, value)
 		assert.Error(err)
-		assert.Equal("error: value too large", err.Error())
+		assert.Equal("error: value too large 17 > 16", err.Error())
 	})
 }
 
@@ -393,7 +389,7 @@ func TestLocking(t *testing.T) {
 
 	_, err = Open(testdir)
 	assert.Error(err)
-	assert.Equal("error: database locked", err.Error())
+	assert.Equal(fmt.Sprintf("error: database locked %s", testdir), err.Error())
 }
 
 type benchmarkTestCase struct {

datafile.go

@@ -96,6 +96,8 @@ func (df *Datafile) Sync() error {
 }
 
 func (df *Datafile) Size() (int64, error) {
+	df.RLock()
+	defer df.RUnlock()
 	return df.offset, nil
 }
 
@@ -123,13 +125,13 @@ func (df *Datafile) Write(e pb.Entry) (int64, error) {
 		return -1, ErrReadonly
 	}
 
+	df.Lock()
+	defer df.Unlock()
+
 	e.Index = df.offset
 	e.Timestamp = time.Now().Unix()
 
-	df.Lock()
 	n, err := df.enc.Encode(&e)
-	df.Unlock()
-
 	if err != nil {
 		return -1, err
 	}

go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/pkg/errors v0.8.1
 	github.com/prologic/msgbus v0.1.1
+	github.com/prologic/trie v0.0.0-20190316011403-395e39dac705
 	github.com/prometheus/client_golang v0.9.2 // indirect
 	github.com/sirupsen/logrus v1.3.0
 	github.com/spf13/cobra v0.0.3

go.sum

@@ -42,6 +42,8 @@ github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINE
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prologic/msgbus v0.1.1/go.mod h1:B3Qu4/U2FP08x93jUzp9E8bl155+cIgDH2DUGRK6OZk=
+github.com/prologic/trie v0.0.0-20190316011403-395e39dac705 h1:2J+cSlAeECj0lfMKSmM7n5OlIio+yLovaKLZJzwLc6U=
+github.com/prologic/trie v0.0.0-20190316011403-395e39dac705/go.mod h1:LFuDmpHJGmciXd8Rl5YMhVlLMps9gz2GtYLzwxrFhzs=
 github.com/prometheus/client_golang v0.9.2 h1:awm861/B8OKDd2I/6o1dy3ra4BamzKhYOiGItCeZ740=
 github.com/prometheus/client_golang v0.9.2/go.mod h1:OsXs2jCmiKlQ1lTBmv21f2mNfw4xf/QclQDMrYNZzcM=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910 h1:idejC8f05m9MGOsuEi1ATq9shN03HrxNkD/luQvxCv8=