move FreelistType from internal/common to top level package bbolt

Signed-off-by: Benjamin Wang <wachao@vmware.com>

db.go

@@ -18,13 +18,18 @@ import (
 // The time elapsed between consecutive file locking attempts.
 const flockRetryTimeout = 50 * time.Millisecond
 
-// Export both FreelistArrayType and FreelistMapType so as to keep API compatibility.
+// FreelistType is the type of the freelist backend
+type FreelistType string
+
 // TODO(ahrtr): eventually we should (step by step)
-//  1. default to FreelistMapType;
-//  2. remove the FreelistArrayType and do not export FreelistMapType;
+//  1. default to `FreelistMapType`;
+//  2. remove the `FreelistArrayType`, do not export `FreelistMapType`
+//     and remove field `FreelistType' from both `DB` and `Options`;
 const (
-	FreelistArrayType = common.FreelistArrayType
-	FreelistMapType   = common.FreelistMapType
+	// FreelistArrayType indicates backend freelist type is array
+	FreelistArrayType = FreelistType("array")
+	// FreelistMapType indicates backend freelist type is hashmap
+	FreelistMapType = FreelistType("hashmap")
 )
 
 // DB represents a collection of buckets persisted to a file on disk.
@@ -59,7 +64,7 @@ type DB struct {
 	// The alternative one is using hashmap, it is faster in almost all circumstances
 	// but it doesn't guarantee that it offers the smallest page id available. In normal case it is safe.
 	// The default type is array
-	FreelistType common.FreelistType
+	FreelistType FreelistType
 
 	// When true, skips the truncate call when growing the database.
 	// Setting this to true is only safe on non-ext3/ext4 systems.
@@ -1211,7 +1216,7 @@ type Options struct {
 	// The alternative one is using hashmap, it is faster in almost all circumstances
 	// but it doesn't guarantee that it offers the smallest page id available. In normal case it is safe.
 	// The default type is array
-	FreelistType common.FreelistType
+	FreelistType FreelistType
 
 	// Open database in read-only mode. Uses flock(..., LOCK_SH |LOCK_NB) to
 	// grab a shared lock (UNIX).
@@ -1253,7 +1258,7 @@ type Options struct {
 var DefaultOptions = &Options{
 	Timeout:      0,
 	NoGrowSync:   false,
-	FreelistType: common.FreelistArrayType,
+	FreelistType: FreelistArrayType,
 }
 
 // Stats represents statistics about the database.

freelist.go

@@ -22,7 +22,7 @@ type pidSet map[common.Pgid]struct{}
 // freelist represents a list of all pages that are available for allocation.
 // It also tracks pages that have been freed but are still in use by open transactions.
 type freelist struct {
-	freelistType   common.FreelistType                       // freelist type
+	freelistType   FreelistType                              // freelist type
 	ids            []common.Pgid                             // all free and available free page ids.
 	allocs         map[common.Pgid]common.Txid               // mapping of Txid that allocated a pgid.
 	pending        map[common.Txid]*txPending                // mapping of soon-to-be free page ids by tx.
@@ -38,7 +38,7 @@ type freelist struct {
 }
 
 // newFreelist returns an empty, initialized freelist.
-func newFreelist(freelistType common.FreelistType) *freelist {
+func newFreelist(freelistType FreelistType) *freelist {
 	f := &freelist{
 		freelistType: freelistType,
 		allocs:       make(map[common.Pgid]common.Txid),
@@ -49,7 +49,7 @@ func newFreelist(freelistType common.FreelistType) *freelist {
 		backwardMap:  make(map[common.Pgid]uint64),
 	}
 
-	if freelistType == common.FreelistMapType {
+	if freelistType == FreelistMapType {
 		f.allocate = f.hashmapAllocate
 		f.free_count = f.hashmapFreeCount
 		f.mergeSpans = f.hashmapMergeSpans

freelist_test.go

@@ -181,7 +181,7 @@ func TestFreelist_releaseRange(t *testing.T) {
 
 func TestFreelistHashmap_allocate(t *testing.T) {
 	f := newTestFreelist()
-	if f.freelistType != common.FreelistMapType {
+	if f.freelistType != FreelistMapType {
 		t.Skip()
 	}
 
@@ -211,7 +211,7 @@ func TestFreelistHashmap_allocate(t *testing.T) {
 // Ensure that a freelist can find contiguous blocks of pages.
 func TestFreelistArray_allocate(t *testing.T) {
 	f := newTestFreelist()
-	if f.freelistType != common.FreelistArrayType {
+	if f.freelistType != FreelistArrayType {
 		t.Skip()
 	}
 	ids := []common.Pgid{3, 4, 5, 6, 7, 9, 12, 13, 18}
@@ -403,7 +403,7 @@ func Test_freelist_mergeWithExist(t *testing.T) {
 	}
 	for _, tt := range tests {
 		f := newTestFreelist()
-		if f.freelistType == common.FreelistArrayType {
+		if f.freelistType == FreelistArrayType {
 			t.Skip()
 		}
 		f.readIDs(tt.ids)
@@ -427,9 +427,9 @@ func Test_freelist_mergeWithExist(t *testing.T) {
 
 // newTestFreelist get the freelist type from env and initial the freelist
 func newTestFreelist() *freelist {
-	freelistType := common.FreelistArrayType
-	if env := os.Getenv(TestFreelistType); env == string(common.FreelistMapType) {
-		freelistType = common.FreelistMapType
+	freelistType := FreelistArrayType
+	if env := os.Getenv(TestFreelistType); env == string(FreelistMapType) {
+		freelistType = FreelistMapType
 	}
 
 	return newFreelist(freelistType)
@@ -437,7 +437,7 @@ func newTestFreelist() *freelist {
 
 func Test_freelist_hashmapGetFreePageIDs(t *testing.T) {
 	f := newTestFreelist()
-	if f.freelistType == common.FreelistArrayType {
+	if f.freelistType == FreelistArrayType {
 		t.Skip()
 	}
 
@@ -461,7 +461,7 @@ func Test_freelist_hashmapGetFreePageIDs(t *testing.T) {
 
 func Benchmark_freelist_hashmapGetFreePageIDs(b *testing.B) {
 	f := newTestFreelist()
-	if f.freelistType == common.FreelistArrayType {
+	if f.freelistType == FreelistArrayType {
 		b.Skip()
 	}
 

internal/btesting/btesting.go

@@ -13,7 +13,6 @@ import (
 	"github.com/stretchr/testify/require"
 
 	bolt "go.etcd.io/bbolt"
-	"go.etcd.io/bbolt/internal/common"
 )
 
 var statsFlag = flag.Bool("stats", false, "show performance stats")
@@ -50,9 +49,9 @@ func MustOpenDBWithOption(t testing.TB, f string, o *bolt.Options) *DB {
 		o = bolt.DefaultOptions
 	}
 
-	freelistType := common.FreelistArrayType
-	if env := os.Getenv(TestFreelistType); env == string(common.FreelistMapType) {
-		freelistType = common.FreelistMapType
+	freelistType := bolt.FreelistArrayType
+	if env := os.Getenv(TestFreelistType); env == string(bolt.FreelistMapType) {
+		freelistType = bolt.FreelistMapType
 	}
 
 	o.FreelistType = freelistType

internal/common/types.go

@@ -36,15 +36,5 @@ const (
 // DefaultPageSize is the default page size for db which is set to the OS page size.
 var DefaultPageSize = os.Getpagesize()
 
-// FreelistType is the type of the freelist backend
-type FreelistType string
-
-const (
-	// FreelistArrayType indicates backend freelist type is array
-	FreelistArrayType = FreelistType("array")
-	// FreelistMapType indicates backend freelist type is hashmap
-	FreelistMapType = FreelistType("hashmap")
-)
-
 // Txid represents the internal transaction identifier.
 type Txid uint64