first review by ben

Signed-off-by: Thomas Jungblut <[email protected]>

Author: tjungblu

allocate_test.go

@@ -8,7 +8,7 @@ import (
 )
 
 func TestTx_allocatePageStats(t *testing.T) {
-	for n, f := range map[string]freelist.Freelist{"hashmap": freelist.NewHashMap(), "array": freelist.NewArray()} {
+	for n, f := range map[string]freelist.Interface{"hashmap": freelist.NewHashMapFreelist(), "array": freelist.NewArrayFreelist()} {
 		t.Run(n, func(t *testing.T) {
 			ids := []common.Pgid{2, 3}
 			f.Init(ids)

db.go

@@ -135,7 +135,7 @@ type DB struct {
 	rwtx     *Tx
 	txs      []*Tx
 
-	freelist           fl.Freelist
+	freelist           fl.Interface
 	freelistSerializer fl.Serializable
 	freelistLoad       sync.Once
 
@@ -1286,11 +1286,11 @@ func (db *DB) freepages() []common.Pgid {
 	return fids
 }
 
-func newFreelist(freelistType FreelistType) fl.Freelist {
+func newFreelist(freelistType FreelistType) fl.Interface {
 	if freelistType == FreelistMapType {
-		return fl.NewHashMap()
+		return fl.NewHashMapFreelist()
 	}
-	return fl.NewArray()
+	return fl.NewArrayFreelist()
 }
 
 // Options represents the options that can be set when opening a database.

internal/freelist/array.go

@@ -7,18 +7,18 @@ import (
 	"go.etcd.io/bbolt/internal/common"
 )
 
-type Array struct {
+type array struct {
 	shared
 
 	ids []common.Pgid // all free and available free page ids.
 }
 
-func (f *Array) Init(ids common.Pgids) {
+func (f *array) Init(ids common.Pgids) {
 	f.ids = ids
 	f.reindex(f.FreePageIds(), f.pendingPageIds())
 }
 
-func (f *Array) Allocate(txid common.Txid, n int) common.Pgid {
+func (f *array) Allocate(txid common.Txid, n int) common.Pgid {
 	if len(f.ids) == 0 {
 		return 0
 	}
@@ -60,19 +60,19 @@ func (f *Array) Allocate(txid common.Txid, n int) common.Pgid {
 	return 0
 }
 
-func (f *Array) Count() int {
+func (f *array) Count() int {
 	return f.FreeCount() + f.PendingCount()
 }
 
-func (f *Array) FreeCount() int {
+func (f *array) FreeCount() int {
 	return len(f.ids)
 }
 
-func (f *Array) FreePageIds() common.Pgids {
+func (f *array) FreePageIds() common.Pgids {
 	return f.ids
 }
 
-func (f *Array) mergeSpans(ids common.Pgids) {
+func (f *array) mergeSpans(ids common.Pgids) {
 	sort.Sort(ids)
 	common.Verify(func() {
 		idsIdx := make(map[common.Pgid]struct{})
@@ -102,8 +102,8 @@ func (f *Array) mergeSpans(ids common.Pgids) {
 	f.ids = common.Pgids(f.ids).Merge(ids)
 }
 
-func NewArray() *Array {
-	a := &Array{
+func NewArrayFreelist() Interface {
+	a := &array{
 		shared: shared{
 			pending: make(map[common.Txid]*txPending),
 			allocs:  make(map[common.Pgid]common.Txid),

internal/freelist/array_test.go

@@ -9,7 +9,7 @@ import (
 
 // Ensure that a freelist can find contiguous blocks of pages.
 func TestFreelistArray_allocate(t *testing.T) {
-	f := NewArray()
+	f := NewArrayFreelist()
 	ids := []common.Pgid{3, 4, 5, 6, 7, 9, 12, 13, 18}
 	f.Init(ids)
 	if id := int(f.Allocate(1, 3)); id != 3 {

internal/freelist/freelist.go

@@ -6,7 +6,7 @@ import (
 	"go.etcd.io/bbolt/internal/common"
 )
 
-type Freelist interface {
+type Interface interface {
 	// Init initializes this freelist with the given list of pages.
 	Init(ids common.Pgids)
 
@@ -48,7 +48,7 @@ type Freelist interface {
 
 // Copyall copies a list of all free ids and all pending ids in one sorted list.
 // f.count returns the minimum length required for dst.
-func Copyall(f Freelist, dst []common.Pgid) {
+func Copyall(f Interface, dst []common.Pgid) {
 	m := make(common.Pgids, 0, f.PendingCount())
 	for _, txp := range f.pendingPageIds() {
 		m = append(m, txp.ids...)
@@ -58,13 +58,13 @@ func Copyall(f Freelist, dst []common.Pgid) {
 }
 
 // Reload reads the freelist from a page and filters out pending items.
-func Reload(s Serializable, f Freelist, p *common.Page) {
+func Reload(s Serializable, f Interface, p *common.Page) {
 	s.Read(f, p)
 	NoSyncReload(f, p.FreelistPageIds())
 }
 
 // NoSyncReload reads the freelist from Pgids and filters out pending items.
-func NoSyncReload(f Freelist, pgIds common.Pgids) {
+func NoSyncReload(f Interface, pgIds common.Pgids) {
 	// Build a cache of only pending pages.
 	pcache := make(map[common.Pgid]bool)
 	for _, txp := range f.pendingPageIds() {
@@ -76,7 +76,7 @@ func NoSyncReload(f Freelist, pgIds common.Pgids) {
 	// Check each page in the freelist and build a new available freelist
 	// with any pages not in the pending lists.
 	var a []common.Pgid
-	for _, id := range f.FreePageIds() {
+	for _, id := range pgIds {
 		if !pcache[id] {
 			a = append(a, id)
 		}

internal/freelist/freelist_test.go

@@ -226,10 +226,10 @@ func Test_freelist_ReadIDs_and_getFreePageIDs(t *testing.T) {
 }
 
 // newTestFreelist get the freelist type from env and initial the freelist
-func newTestFreelist() Freelist {
+func newTestFreelist() Interface {
 	if env := os.Getenv(TestFreelistType); env == "map" {
-		return NewHashMap()
+		return NewHashMapFreelist()
 	}
 
-	return NewArray()
+	return NewArrayFreelist()
 }

internal/freelist/hashmap.go

@@ -11,7 +11,7 @@ import (
 // pidSet holds the set of starting pgids which have the same span size
 type pidSet map[common.Pgid]struct{}
 
-type HashMap struct {
+type hashMap struct {
 	shared
 
 	freePagesCount uint64                 // count of free pages(hashmap version)
@@ -20,7 +20,7 @@ type HashMap struct {
 	backwardMap    map[common.Pgid]uint64 // key is end pgid, value is its span size
 }
 
-func (f *HashMap) Init(pgids common.Pgids) {
+func (f *hashMap) Init(pgids common.Pgids) {
 	if len(pgids) == 0 {
 		return
 	}
@@ -58,7 +58,7 @@ func (f *HashMap) Init(pgids common.Pgids) {
 	f.reindex(f.FreePageIds(), f.pendingPageIds())
 }
 
-func (f *HashMap) Allocate(txid common.Txid, n int) common.Pgid {
+func (f *hashMap) Allocate(txid common.Txid, n int) common.Pgid {
 	if n == 0 {
 		return 0
 	}
@@ -105,11 +105,11 @@ func (f *HashMap) Allocate(txid common.Txid, n int) common.Pgid {
 	return 0
 }
 
-func (f *HashMap) Count() int {
+func (f *hashMap) Count() int {
 	return f.FreeCount() + f.PendingCount()
 }
 
-func (f *HashMap) FreeCount() int {
+func (f *hashMap) FreeCount() int {
 	common.Verify(func() {
 		expectedFreePageCount := f.hashmapFreeCountSlow()
 		common.Assert(int(f.freePagesCount) == expectedFreePageCount,
@@ -118,7 +118,7 @@ func (f *HashMap) FreeCount() int {
 	return int(f.freePagesCount)
 }
 
-func (f *HashMap) FreePageIds() common.Pgids {
+func (f *hashMap) FreePageIds() common.Pgids {
 	count := f.FreeCount()
 	if count == 0 {
 		return nil
@@ -143,15 +143,15 @@ func (f *HashMap) FreePageIds() common.Pgids {
 	return m
 }
 
-func (f *HashMap) hashmapFreeCountSlow() int {
+func (f *hashMap) hashmapFreeCountSlow() int {
 	count := 0
 	for _, size := range f.forwardMap {
 		count += int(size)
 	}
 	return count
 }
 
-func (f *HashMap) addSpan(start common.Pgid, size uint64) {
+func (f *hashMap) addSpan(start common.Pgid, size uint64) {
 	f.backwardMap[start-1+common.Pgid(size)] = size
 	f.forwardMap[start] = size
 	if _, ok := f.freemaps[size]; !ok {
@@ -162,7 +162,7 @@ func (f *HashMap) addSpan(start common.Pgid, size uint64) {
 	f.freePagesCount += size
 }
 
-func (f *HashMap) delSpan(start common.Pgid, size uint64) {
+func (f *hashMap) delSpan(start common.Pgid, size uint64) {
 	delete(f.forwardMap, start)
 	delete(f.backwardMap, start+common.Pgid(size-1))
 	delete(f.freemaps[size], start)
@@ -172,7 +172,7 @@ func (f *HashMap) delSpan(start common.Pgid, size uint64) {
 	f.freePagesCount -= size
 }
 
-func (f *HashMap) mergeSpans(ids common.Pgids) {
+func (f *hashMap) mergeSpans(ids common.Pgids) {
 	common.Verify(func() {
 		ids1Freemap := f.idsFromFreemaps()
 		ids2Forward := f.idsFromForwardMap()
@@ -207,7 +207,7 @@ func (f *HashMap) mergeSpans(ids common.Pgids) {
 }
 
 // mergeWithExistingSpan merges pid to the existing free spans, try to merge it backward and forward
-func (f *HashMap) mergeWithExistingSpan(pid common.Pgid) {
+func (f *hashMap) mergeWithExistingSpan(pid common.Pgid) {
 	prev := pid - 1
 	next := pid + 1
 
@@ -236,7 +236,7 @@ func (f *HashMap) mergeWithExistingSpan(pid common.Pgid) {
 
 // idsFromFreemaps get all free page IDs from f.freemaps.
 // used by test only.
-func (f *HashMap) idsFromFreemaps() map[common.Pgid]struct{} {
+func (f *hashMap) idsFromFreemaps() map[common.Pgid]struct{} {
 	ids := make(map[common.Pgid]struct{})
 	for size, idSet := range f.freemaps {
 		for start := range idSet {
@@ -254,7 +254,7 @@ func (f *HashMap) idsFromFreemaps() map[common.Pgid]struct{} {
 
 // idsFromForwardMap get all free page IDs from f.forwardMap.
 // used by test only.
-func (f *HashMap) idsFromForwardMap() map[common.Pgid]struct{} {
+func (f *hashMap) idsFromForwardMap() map[common.Pgid]struct{} {
 	ids := make(map[common.Pgid]struct{})
 	for start, size := range f.forwardMap {
 		for i := 0; i < int(size); i++ {
@@ -270,7 +270,7 @@ func (f *HashMap) idsFromForwardMap() map[common.Pgid]struct{} {
 
 // idsFromBackwardMap get all free page IDs from f.backwardMap.
 // used by test only.
-func (f *HashMap) idsFromBackwardMap() map[common.Pgid]struct{} {
+func (f *hashMap) idsFromBackwardMap() map[common.Pgid]struct{} {
 	ids := make(map[common.Pgid]struct{})
 	for end, size := range f.backwardMap {
 		for i := 0; i < int(size); i++ {
@@ -284,8 +284,8 @@ func (f *HashMap) idsFromBackwardMap() map[common.Pgid]struct{} {
 	return ids
 }
 
-func NewHashMap() *HashMap {
-	hm := &HashMap{
+func NewHashMapFreelist() Interface {
+	hm := &hashMap{
 		shared: shared{
 			allocs:  make(map[common.Pgid]common.Txid),
 			cache:   make(map[common.Pgid]struct{}),

internal/freelist/hashmap_test.go

@@ -7,7 +7,7 @@ import (
 )
 
 func TestFreelistHashmap_allocate(t *testing.T) {
-	f := NewHashMap()
+	f := NewHashMapFreelist()
 
 	ids := []common.Pgid{3, 4, 5, 6, 7, 9, 12, 13, 18}
 	f.Init(ids)

internal/freelist/serde.go

@@ -10,20 +10,20 @@ import (
 
 type Serializable interface {
 	// Read calls Init with the page ids stored in te given page.
-	Read(f Freelist, page *common.Page)
+	Read(f Interface, page *common.Page)
 
 	// Write writes the freelist into the given page.
-	Write(f Freelist, page *common.Page)
+	Write(f Interface, page *common.Page)
 
-	// EstimatedWritePageSize returns the size of the page after serialization in Write.
+	// EstimatedWritePageSize returns the size of the freelist after serialization in Write.
 	// This should never underestimate the size.
-	EstimatedWritePageSize(f Freelist) int
+	EstimatedWritePageSize(f Interface) int
 }
 
 type Serializer struct {
 }
 
-func (s Serializer) Read(f Freelist, p *common.Page) {
+func (s Serializer) Read(f Interface, p *common.Page) {
 	if !p.IsFreelistPage() {
 		panic(fmt.Sprintf("invalid freelist page: %d, page type is %s", p.Id(), p.Typ()))
 	}
@@ -44,7 +44,7 @@ func (s Serializer) Read(f Freelist, p *common.Page) {
 	}
 }
 
-func (s Serializer) EstimatedWritePageSize(f Freelist) int {
+func (s Serializer) EstimatedWritePageSize(f Interface) int {
 	n := f.Count()
 	if n >= 0xFFFF {
 		// The first element will be used to store the count. See freelist.write.
@@ -53,7 +53,7 @@ func (s Serializer) EstimatedWritePageSize(f Freelist) int {
 	return int(common.PageHeaderSize) + (int(unsafe.Sizeof(common.Pgid(0))) * n)
 }
 
-func (s Serializer) Write(f Freelist, p *common.Page) {
+func (s Serializer) Write(f Interface, p *common.Page) {
 	// Combine the old free pgids and pgids waiting on an open transaction.
 
 	// Update the header flag.