diff --git a/db.go b/db.go
index 349f187ae..f862031e0 100644
--- a/db.go
+++ b/db.go
@@ -134,8 +134,9 @@ type DB struct {
rwtx *Tx
txs []*Tx
- freelist fl.Interface
- freelistLoad sync.Once
+ freelist fl.Interface
+ freelistLoad sync.Once
+ freelistReadWriter fl.ReadWriter
pagePool sync.Pool
@@ -417,12 +418,13 @@ func (db *DB) getPageSizeFromSecondMeta() (int, bool, error) {
func (db *DB) loadFreelist() {
db.freelistLoad.Do(func() {
db.freelist = newFreelist(db.FreelistType)
+ db.freelistReadWriter = fl.NewSortedSerializer()
if !db.hasSyncedFreelist() {
// Reconstruct free list by scanning the DB.
db.freelist.Init(db.freepages())
} else {
// Read free list from freelist page.
- db.freelist.Read(db.page(db.meta().Freelist()))
+ db.freelistReadWriter.Read(db.freelist, db.page(db.meta().Freelist()))
}
db.stats.FreePageN = db.freelist.FreeCount()
})
diff --git a/internal/freelist/array.go b/internal/freelist/array.go
index 93ccc5edc..f98e45065 100644
--- a/internal/freelist/array.go
+++ b/internal/freelist/array.go
@@ -8,17 +8,14 @@ import (
)
type array struct {
- *shared
-
ids []common.Pgid // all free and available free page ids.
}
func (f *array) Init(ids common.Pgids) {
f.ids = ids
- f.reindex()
}
-func (f *array) Allocate(txid common.Txid, n int) common.Pgid {
+func (f *array) alloc(txid common.Txid, n int, allocs *map[common.Pgid]common.Txid, cache *map[common.Pgid]struct{}) common.Pgid {
if len(f.ids) == 0 {
return 0
}
@@ -49,9 +46,9 @@ func (f *array) Allocate(txid common.Txid, n int) common.Pgid {
// Remove from the free cache.
for i := common.Pgid(0); i < common.Pgid(n); i++ {
- delete(f.cache, initial+i)
+ delete(*cache, initial+i)
}
- f.allocs[initial] = txid
+ (*allocs)[initial] = txid
return initial
}
@@ -64,7 +61,7 @@ func (f *array) FreeCount() int {
return len(f.ids)
}
-func (f *array) freePageIds() common.Pgids {
+func (f *array) FreePageIds() common.Pgids {
return f.ids
}
@@ -99,9 +96,5 @@ func (f *array) mergeSpans(ids common.Pgids) {
}
func NewArrayFreelist() Interface {
- a := &array{
- shared: newShared(),
- }
- a.Interface = a
- return a
+ return newShared(&array{})
}
diff --git a/internal/freelist/array_test.go b/internal/freelist/array_test.go
index 31b0702dc..b4ccfd9e4 100644
--- a/internal/freelist/array_test.go
+++ b/internal/freelist/array_test.go
@@ -33,8 +33,8 @@ func TestFreelistArray_allocate(t *testing.T) {
if id := int(f.Allocate(1, 0)); id != 0 {
t.Fatalf("exp=0; got=%v", id)
}
- if exp := common.Pgids([]common.Pgid{9, 18}); !reflect.DeepEqual(exp, f.freePageIds()) {
- t.Fatalf("exp=%v; got=%v", exp, f.freePageIds())
+ if exp := common.Pgids([]common.Pgid{9, 18}); !reflect.DeepEqual(exp, f.FreePageIds()) {
+ t.Fatalf("exp=%v; got=%v", exp, f.FreePageIds())
}
if id := int(f.Allocate(1, 1)); id != 9 {
@@ -46,7 +46,7 @@ func TestFreelistArray_allocate(t *testing.T) {
if id := int(f.Allocate(1, 1)); id != 0 {
t.Fatalf("exp=0; got=%v", id)
}
- if exp := common.Pgids([]common.Pgid{}); !reflect.DeepEqual(exp, f.freePageIds()) {
- t.Fatalf("exp=%v; got=%v", exp, f.freePageIds())
+ if exp := common.Pgids([]common.Pgid{}); !reflect.DeepEqual(exp, f.FreePageIds()) {
+ t.Fatalf("exp=%v; got=%v", exp, f.FreePageIds())
}
}
diff --git a/internal/freelist/freelist.go b/internal/freelist/freelist.go
index 3d77d8f94..160077047 100644
--- a/internal/freelist/freelist.go
+++ b/internal/freelist/freelist.go
@@ -6,36 +6,34 @@ import (
type ReadWriter interface {
// Read calls Init with the page ids stored in the given page.
- Read(page *common.Page)
+ Read(f Interface, page *common.Page)
// Write writes the freelist into the given page.
- Write(page *common.Page)
+ Write(f Interface, page *common.Page)
// EstimatedWritePageSize returns the size of the freelist after serialization in Write.
// This should never underestimate the size.
- EstimatedWritePageSize() int
+ EstimatedWritePageSize(f Interface) int
}
-type Interface interface {
- ReadWriter
-
+type allocator interface {
// Init initializes this freelist with the given list of pages.
Init(ids common.Pgids)
- // Allocate tries to allocate the given number of contiguous pages
- // from the free list pages. It returns the starting page ID if
- // available; otherwise, it returns 0.
- Allocate(txid common.Txid, numPages int) common.Pgid
-
- // Count returns the number of free and pending pages.
- Count() int
-
// FreeCount returns the number of free pages.
FreeCount() int
- // PendingCount returns the number of pending pages.
- PendingCount() int
+ // FreePageIds returns the IDs of all free pages.
+ FreePageIds() common.Pgids
+ // mergeSpans is merging the given pages into the freelist
+ mergeSpans(ids common.Pgids)
+
+ // TODO(thomas): this is necessary to decouple, but leaks internals
+ alloc(txid common.Txid, numPages int, allocs *map[common.Pgid]common.Txid, cache *map[common.Pgid]struct{}) common.Pgid
+}
+
+type txManager interface {
// AddReadonlyTXID adds a given read-only transaction id for pending page tracking.
AddReadonlyTXID(txid common.Txid)
@@ -45,6 +43,31 @@ type Interface interface {
// ReleasePendingPages releases any pages associated with closed read-only transactions.
ReleasePendingPages()
+ // pendingPageIds returns all pending pages by transaction id.
+ pendingPageIds() map[common.Txid]*txPending
+
+ // release moves all page ids for a transaction id (or older) to the freelist.
+ release(txId common.Txid)
+
+ // releaseRange moves pending pages allocated within an extent [begin,end] to the free list.
+ releaseRange(begin, end common.Txid)
+}
+
+type Interface interface {
+ allocator
+ txManager
+
+ // Allocate tries to allocate the given number of contiguous pages
+ // from the free list pages. It returns the starting page ID if
+ // available; otherwise, it returns 0.
+ Allocate(txid common.Txid, numPages int) common.Pgid
+
+ // Count returns the number of free and pending pages.
+ Count() int
+
+ // PendingCount returns the number of pending pages.
+ PendingCount() int
+
// Free releases a page and its overflow for a given transaction id.
// If the page is already free then a panic will occur.
Free(txId common.Txid, p *common.Page)
@@ -55,28 +78,9 @@ type Interface interface {
// Rollback removes the pages from a given pending tx.
Rollback(txId common.Txid)
- // 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.
- Copyall(dst []common.Pgid)
-
- // Reload reads the freelist from a page and filters out pending items.
- Reload(p *common.Page)
+ // List returns a list of all free ids and all pending ids in one sorted list.
+ List() common.Pgids
- // NoSyncReload reads the freelist from Pgids and filters out pending items.
- NoSyncReload(pgIds common.Pgids)
-
- // freePageIds returns the IDs of all free pages.
- freePageIds() common.Pgids
-
- // pendingPageIds returns all pending pages by transaction id.
- pendingPageIds() map[common.Txid]*txPending
-
- // release moves all page ids for a transaction id (or older) to the freelist.
- release(txId common.Txid)
-
- // releaseRange moves pending pages allocated within an extent [begin,end] to the free list.
- releaseRange(begin, end common.Txid)
-
- // mergeSpans is merging the given pages into the freelist
- mergeSpans(ids common.Pgids)
+ // Reload reads the freelist from Pgids and filters out pending items.
+ Reload(pgIds common.Pgids)
}
diff --git a/internal/freelist/freelist_test.go b/internal/freelist/freelist_test.go
index df7c7697e..14f8f4487 100644
--- a/internal/freelist/freelist_test.go
+++ b/internal/freelist/freelist_test.go
@@ -40,13 +40,13 @@ func TestFreelist_release(t *testing.T) {
f.Free(102, common.NewPage(39, 0, 0, 0))
f.release(100)
f.release(101)
- if exp := common.Pgids([]common.Pgid{9, 12, 13}); !reflect.DeepEqual(exp, f.freePageIds()) {
- t.Fatalf("exp=%v; got=%v", exp, f.freePageIds())
+ if exp := common.Pgids([]common.Pgid{9, 12, 13}); !reflect.DeepEqual(exp, f.FreePageIds()) {
+ t.Fatalf("exp=%v; got=%v", exp, f.FreePageIds())
}
f.release(102)
- if exp := common.Pgids([]common.Pgid{9, 12, 13, 39}); !reflect.DeepEqual(exp, f.freePageIds()) {
- t.Fatalf("exp=%v; got=%v", exp, f.freePageIds())
+ if exp := common.Pgids([]common.Pgid{9, 12, 13, 39}); !reflect.DeepEqual(exp, f.FreePageIds()) {
+ t.Fatalf("exp=%v; got=%v", exp, f.FreePageIds())
}
}
@@ -173,8 +173,8 @@ func TestFreelist_releaseRange(t *testing.T) {
f.releaseRange(r.begin, r.end)
}
- if exp := common.Pgids(c.wantFree); !reflect.DeepEqual(exp, f.freePageIds()) {
- t.Errorf("exp=%v; got=%v for %s", exp, f.freePageIds(), c.title)
+ if exp := common.Pgids(c.wantFree); !reflect.DeepEqual(exp, f.FreePageIds()) {
+ t.Errorf("exp=%v; got=%v for %s", exp, f.FreePageIds(), c.title)
}
}
}
@@ -194,11 +194,12 @@ func TestFreelist_read(t *testing.T) {
// Deserialize page into a freelist.
f := newTestFreelist()
- f.Read(page)
+ s := SortedSerializer{}
+ s.Read(f, page)
// Ensure that there are two page ids in the freelist.
- if exp := common.Pgids([]common.Pgid{23, 50}); !reflect.DeepEqual(exp, f.freePageIds()) {
- t.Fatalf("exp=%v; got=%v", exp, f.freePageIds())
+ if exp := common.Pgids([]common.Pgid{23, 50}); !reflect.DeepEqual(exp, f.FreePageIds()) {
+ t.Fatalf("exp=%v; got=%v", exp, f.FreePageIds())
}
}
@@ -207,21 +208,22 @@ func TestFreelist_write(t *testing.T) {
// Create a freelist and write it to a page.
var buf [4096]byte
f := newTestFreelist()
+ s := SortedSerializer{}
f.Init([]common.Pgid{12, 39})
f.pendingPageIds()[100] = &txPending{ids: []common.Pgid{28, 11}}
f.pendingPageIds()[101] = &txPending{ids: []common.Pgid{3}}
p := (*common.Page)(unsafe.Pointer(&buf[0]))
- f.Write(p)
+ s.Write(f, p)
// Read the page back out.
f2 := newTestFreelist()
- f2.Read(p)
+ s.Read(f2, p)
// Ensure that the freelist is correct.
// All pages should be present and in reverse order.
- if exp := common.Pgids([]common.Pgid{3, 11, 12, 28, 39}); !reflect.DeepEqual(exp, f2.freePageIds()) {
- t.Fatalf("exp=%v; got=%v", exp, f2.freePageIds())
+ if exp := common.Pgids([]common.Pgid{3, 11, 12, 28, 39}); !reflect.DeepEqual(exp, f2.FreePageIds()) {
+ t.Fatalf("exp=%v; got=%v", exp, f2.FreePageIds())
}
}
@@ -258,7 +260,7 @@ func Test_freelist_ReadIDs_and_getFreePageIDs(t *testing.T) {
f.Init(exp)
- if got := f.freePageIds(); !reflect.DeepEqual(exp, got) {
+ if got := f.FreePageIds(); !reflect.DeepEqual(exp, got) {
t.Fatalf("exp=%v; got=%v", exp, got)
}
@@ -266,7 +268,7 @@ func Test_freelist_ReadIDs_and_getFreePageIDs(t *testing.T) {
var exp2 []common.Pgid
f2.Init(exp2)
- if got2 := f2.freePageIds(); !reflect.DeepEqual(got2, common.Pgids(exp2)) {
+ if got2 := f2.FreePageIds(); !reflect.DeepEqual(got2, common.Pgids(exp2)) {
t.Fatalf("exp2=%#v; got2=%#v", exp2, got2)
}
diff --git a/internal/freelist/hashmap.go b/internal/freelist/hashmap.go
index a6bad8976..0cbc28875 100644
--- a/internal/freelist/hashmap.go
+++ b/internal/freelist/hashmap.go
@@ -12,8 +12,6 @@ import (
type pidSet map[common.Pgid]struct{}
type hashMap struct {
- *shared
-
freePagesCount uint64 // count of free pages(hashmap version)
freemaps map[uint64]pidSet // key is the size of continuous pages(span), value is a set which contains the starting pgids of same size
forwardMap map[common.Pgid]uint64 // key is start pgid, value is its span size
@@ -54,11 +52,9 @@ func (f *hashMap) Init(pgids common.Pgids) {
if size != 0 && start != 0 {
f.addSpan(start, size)
}
-
- f.reindex()
}
-func (f *hashMap) Allocate(txid common.Txid, n int) common.Pgid {
+func (f *hashMap) alloc(txid common.Txid, n int, allocs *map[common.Pgid]common.Txid, cache *map[common.Pgid]struct{}) common.Pgid {
if n == 0 {
return 0
}
@@ -69,10 +65,10 @@ func (f *hashMap) Allocate(txid common.Txid, n int) common.Pgid {
// remove the span
f.delSpan(pid, uint64(n))
- f.allocs[pid] = txid
+ (*allocs)[pid] = txid
for i := common.Pgid(0); i < common.Pgid(n); i++ {
- delete(f.cache, pid+i)
+ delete(*cache, pid+i)
}
return pid
}
@@ -88,7 +84,7 @@ func (f *hashMap) Allocate(txid common.Txid, n int) common.Pgid {
// remove the initial
f.delSpan(pid, size)
- f.allocs[pid] = txid
+ (*allocs)[pid] = txid
remain := size - uint64(n)
@@ -96,7 +92,7 @@ func (f *hashMap) Allocate(txid common.Txid, n int) common.Pgid {
f.addSpan(pid+common.Pgid(n), remain)
for i := common.Pgid(0); i < common.Pgid(n); i++ {
- delete(f.cache, pid+i)
+ delete(*cache, pid+i)
}
return pid
}
@@ -114,7 +110,7 @@ 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
@@ -280,13 +276,14 @@ func (f *hashMap) idsFromBackwardMap() map[common.Pgid]struct{} {
return ids
}
-func NewHashMapFreelist() Interface {
- hm := &hashMap{
- shared: newShared(),
+func newHashMap() *hashMap {
+ return &hashMap{
freemaps: make(map[uint64]pidSet),
forwardMap: make(map[common.Pgid]uint64),
backwardMap: make(map[common.Pgid]uint64),
}
- hm.Interface = hm
- return hm
+}
+
+func NewHashMapFreelist() Interface {
+ return newShared(newHashMap())
}
diff --git a/internal/freelist/hashmap_test.go b/internal/freelist/hashmap_test.go
index 32cc5dfa0..8c92cdb79 100644
--- a/internal/freelist/hashmap_test.go
+++ b/internal/freelist/hashmap_test.go
@@ -86,12 +86,12 @@ func TestFreelistHashmap_mergeWithExist(t *testing.T) {
},
}
for _, tt := range tests {
- f := newTestHashMapFreelist()
+ f := newHashMap()
f.Init(tt.ids)
f.mergeWithExistingSpan(tt.pgid)
- if got := f.freePageIds(); !reflect.DeepEqual(tt.want, got) {
+ if got := f.FreePageIds(); !reflect.DeepEqual(tt.want, got) {
t.Fatalf("name %s; exp=%v; got=%v", tt.name, tt.want, got)
}
if got := f.forwardMap; !reflect.DeepEqual(tt.wantForwardmap, got) {
@@ -107,7 +107,7 @@ func TestFreelistHashmap_mergeWithExist(t *testing.T) {
}
func TestFreelistHashmap_GetFreePageIDs(t *testing.T) {
- f := newTestHashMapFreelist()
+ f := newHashMap()
N := int32(100000)
fm := make(map[common.Pgid]uint64)
@@ -121,7 +121,7 @@ func TestFreelistHashmap_GetFreePageIDs(t *testing.T) {
}
f.forwardMap = fm
- res := f.freePageIds()
+ res := f.FreePageIds()
if !sort.SliceIsSorted(res, func(i, j int) bool { return res[i] < res[j] }) {
t.Fatalf("pgids not sorted")
@@ -129,7 +129,7 @@ func TestFreelistHashmap_GetFreePageIDs(t *testing.T) {
}
func Benchmark_freelist_hashmapGetFreePageIDs(b *testing.B) {
- f := newTestHashMapFreelist()
+ f := newHashMap()
N := int32(100000)
fm := make(map[common.Pgid]uint64)
i := int32(0)
@@ -145,11 +145,6 @@ func Benchmark_freelist_hashmapGetFreePageIDs(b *testing.B) {
b.ReportAllocs()
b.ResetTimer()
for n := 0; n < b.N; n++ {
- f.freePageIds()
+ f.FreePageIds()
}
}
-
-func newTestHashMapFreelist() *hashMap {
- f := NewHashMapFreelist()
- return f.(*hashMap)
-}
diff --git a/internal/freelist/read_writer.go b/internal/freelist/read_writer.go
new file mode 100644
index 000000000..ad6fd9863
--- /dev/null
+++ b/internal/freelist/read_writer.go
@@ -0,0 +1,82 @@
+package freelist
+
+import (
+ "fmt"
+ "sort"
+ "unsafe"
+
+ "go.etcd.io/bbolt/internal/common"
+)
+
+type SortedSerializer struct {
+}
+
+func (s *SortedSerializer) Read(t Interface, p *common.Page) {
+ if !p.IsFreelistPage() {
+ panic(fmt.Sprintf("invalid freelist page: %d, page type is %s", p.Id(), p.Typ()))
+ }
+
+ ids := p.FreelistPageIds()
+
+ // Copy the list of page ids from the freelist.
+ if len(ids) == 0 {
+ t.Init(nil)
+ } else {
+ // copy the ids, so we don't modify on the freelist page directly
+ idsCopy := make([]common.Pgid, len(ids))
+ copy(idsCopy, ids)
+ // Make sure they're sorted.
+ sort.Sort(common.Pgids(idsCopy))
+
+ t.Init(idsCopy)
+ }
+}
+
+func (s *SortedSerializer) EstimatedWritePageSize(t Interface) int {
+ n := t.Count()
+ if n >= 0xFFFF {
+ // The first element will be used to store the count. See freelist.write.
+ n++
+ }
+ return int(common.PageHeaderSize) + (int(unsafe.Sizeof(common.Pgid(0))) * n)
+}
+
+func (s *SortedSerializer) Write(t Interface, p *common.Page) {
+ // Combine the old free pgids and pgids waiting on an open transaction.
+
+ // Update the header flag.
+ p.SetFlags(common.FreelistPageFlag)
+
+ // The page.count can only hold up to 64k elements so if we overflow that
+ // number then we handle it by putting the size in the first element.
+ l := t.Count()
+ if l == 0 {
+ p.SetCount(uint16(l))
+ } else if l < 0xFFFF {
+ p.SetCount(uint16(l))
+ data := common.UnsafeAdd(unsafe.Pointer(p), unsafe.Sizeof(*p))
+ ids := unsafe.Slice((*common.Pgid)(data), l)
+ copyall(t, ids)
+ } else {
+ p.SetCount(0xFFFF)
+ data := common.UnsafeAdd(unsafe.Pointer(p), unsafe.Sizeof(*p))
+ ids := unsafe.Slice((*common.Pgid)(data), l+1)
+ ids[0] = common.Pgid(l)
+ copyall(t, ids[1:])
+ }
+}
+
+// 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(t Interface, dst []common.Pgid) {
+ m := make(common.Pgids, 0, t.PendingCount())
+ for _, txp := range t.pendingPageIds() {
+ m = append(m, txp.ids...)
+ }
+ sort.Sort(m)
+ common.Mergepgids(dst, t.FreePageIds(), m)
+}
+
+func NewSortedSerializer() ReadWriter {
+ return &SortedSerializer{}
+}
diff --git a/internal/freelist/shared.go b/internal/freelist/shared.go
index 9914cc7af..aabfddcf5 100644
--- a/internal/freelist/shared.go
+++ b/internal/freelist/shared.go
@@ -3,8 +3,8 @@ package freelist
import (
"fmt"
"math"
+ "slices"
"sort"
- "unsafe"
"go.etcd.io/bbolt/internal/common"
)
@@ -16,7 +16,7 @@ type txPending struct {
}
type shared struct {
- Interface
+ allocator
readonlyTXIDs []common.Txid // all readonly transaction IDs.
allocs map[common.Pgid]common.Txid // mapping of Txid that allocated a pgid.
@@ -24,14 +24,24 @@ type shared struct {
pending map[common.Txid]*txPending // mapping of soon-to-be free page ids by tx.
}
-func newShared() *shared {
+func newShared(a allocator) Interface {
return &shared{
- pending: make(map[common.Txid]*txPending),
- allocs: make(map[common.Pgid]common.Txid),
- cache: make(map[common.Pgid]struct{}),
+ allocator: a,
+ pending: make(map[common.Txid]*txPending),
+ allocs: make(map[common.Pgid]common.Txid),
+ cache: make(map[common.Pgid]struct{}),
}
}
+func (t *shared) Init(ids common.Pgids) {
+ t.allocator.Init(ids)
+ t.reindex()
+}
+
+func (t *shared) Allocate(txid common.Txid, n int) common.Pgid {
+ return t.allocator.alloc(txid, n, &t.allocs, &t.cache)
+}
+
func (t *shared) pendingPageIds() map[common.Txid]*txPending {
return t.pending
}
@@ -192,20 +202,7 @@ func (t *shared) releaseRange(begin, end common.Txid) {
t.mergeSpans(m)
}
-// 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 (t *shared) Copyall(dst []common.Pgid) {
- m := make(common.Pgids, 0, t.PendingCount())
- for _, txp := range t.pendingPageIds() {
- m = append(m, txp.ids...)
- }
- sort.Sort(m)
- common.Mergepgids(dst, t.freePageIds(), m)
-}
-
-func (t *shared) Reload(p *common.Page) {
- t.Read(p)
-
+func (t *shared) Reload(pgIds common.Pgids) {
// Build a cache of only pending pages.
pcache := make(map[common.Pgid]bool)
for _, txp := range t.pending {
@@ -217,7 +214,7 @@ func (t *shared) Reload(p *common.Page) {
// 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 t.freePageIds() {
+ for _, id := range pgIds {
if !pcache[id] {
a = append(a, id)
}
@@ -226,30 +223,19 @@ func (t *shared) Reload(p *common.Page) {
t.Init(a)
}
-func (t *shared) NoSyncReload(pgIds common.Pgids) {
- // Build a cache of only pending pages.
- pcache := make(map[common.Pgid]bool)
- for _, txp := range t.pending {
- for _, pendingID := range txp.ids {
- pcache[pendingID] = true
- }
- }
-
- // 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 pgIds {
- if !pcache[id] {
- a = append(a, id)
- }
+func (t *shared) List() common.Pgids {
+ a := slices.Clone(t.FreePageIds())
+ for _, pending := range t.pendingPageIds() {
+ a = append(a, pending.ids...)
}
- t.Init(a)
+ sort.Sort(a)
+ return a
}
// reindex rebuilds the free cache based on available and pending free lists.
func (t *shared) reindex() {
- free := t.freePageIds()
+ free := t.FreePageIds()
pending := t.pendingPageIds()
t.cache = make(map[common.Pgid]struct{}, len(free))
for _, id := range free {
@@ -261,58 +247,3 @@ func (t *shared) reindex() {
}
}
}
-
-func (t *shared) Read(p *common.Page) {
- if !p.IsFreelistPage() {
- panic(fmt.Sprintf("invalid freelist page: %d, page type is %s", p.Id(), p.Typ()))
- }
-
- ids := p.FreelistPageIds()
-
- // Copy the list of page ids from the freelist.
- if len(ids) == 0 {
- t.Init(nil)
- } else {
- // copy the ids, so we don't modify on the freelist page directly
- idsCopy := make([]common.Pgid, len(ids))
- copy(idsCopy, ids)
- // Make sure they're sorted.
- sort.Sort(common.Pgids(idsCopy))
-
- t.Init(idsCopy)
- }
-}
-
-func (t *shared) EstimatedWritePageSize() int {
- n := t.Count()
- if n >= 0xFFFF {
- // The first element will be used to store the count. See freelist.write.
- n++
- }
- return int(common.PageHeaderSize) + (int(unsafe.Sizeof(common.Pgid(0))) * n)
-}
-
-func (t *shared) Write(p *common.Page) {
- // Combine the old free pgids and pgids waiting on an open transaction.
-
- // Update the header flag.
- p.SetFlags(common.FreelistPageFlag)
-
- // The page.count can only hold up to 64k elements so if we overflow that
- // number then we handle it by putting the size in the first element.
- l := t.Count()
- if l == 0 {
- p.SetCount(uint16(l))
- } else if l < 0xFFFF {
- p.SetCount(uint16(l))
- data := common.UnsafeAdd(unsafe.Pointer(p), unsafe.Sizeof(*p))
- ids := unsafe.Slice((*common.Pgid)(data), l)
- t.Copyall(ids)
- } else {
- p.SetCount(0xFFFF)
- data := common.UnsafeAdd(unsafe.Pointer(p), unsafe.Sizeof(*p))
- ids := unsafe.Slice((*common.Pgid)(data), l+1)
- ids[0] = common.Pgid(l)
- t.Copyall(ids[1:])
- }
-}
diff --git a/tx.go b/tx.go
index 7b5db7727..fbc583479 100644
--- a/tx.go
+++ b/tx.go
@@ -285,13 +285,13 @@ func (tx *Tx) Commit() (err error) {
func (tx *Tx) commitFreelist() error {
// Allocate new pages for the new free list. This will overestimate
// the size of the freelist but not underestimate the size (which would be bad).
- p, err := tx.allocate((tx.db.freelist.EstimatedWritePageSize() / tx.db.pageSize) + 1)
+ p, err := tx.allocate((tx.db.freelistReadWriter.EstimatedWritePageSize(tx.db.freelist) / tx.db.pageSize) + 1)
if err != nil {
tx.rollback()
return err
}
- tx.db.freelist.Write(p)
+ tx.db.freelistReadWriter.Write(tx.db.freelist, p)
tx.meta.SetFreelist(p.Id())
return nil
@@ -329,19 +329,24 @@ func (tx *Tx) rollback() {
// When mmap fails, the `data`, `dataref` and `datasz` may be reset to
// zero values, and there is no way to reload free page IDs in this case.
if tx.db.data != nil {
- if !tx.db.hasSyncedFreelist() {
- // Reconstruct free page list by scanning the DB to get the whole free page list.
- // Note: scanning the whole db is heavy if your db size is large in NoSyncFreeList mode.
- tx.db.freelist.NoSyncReload(tx.db.freepages())
- } else {
- // Read free page list from freelist page.
- tx.db.freelist.Reload(tx.db.page(tx.db.meta().Freelist()))
- }
+ tx.reloadFreelist()
}
}
tx.close()
}
+func (tx *Tx) reloadFreelist() {
+ if !tx.db.hasSyncedFreelist() {
+ // Reconstruct free page list by scanning the DB to get the whole free page list.
+ // Note: scanning the whole db is heavy if your db size is large in NoSyncFreeList mode.
+ tx.db.freelist.Reload(tx.db.freepages())
+ } else {
+ // Read free page list from freelist page.
+ tx.db.freelistReadWriter.Read(tx.db.freelist, tx.db.page(tx.db.meta().Freelist()))
+ tx.db.freelist.Reload(tx.db.freelist.FreePageIds())
+ }
+}
+
func (tx *Tx) close() {
if tx.db == nil {
return
@@ -350,7 +355,7 @@ func (tx *Tx) close() {
// Grab freelist stats.
var freelistFreeN = tx.db.freelist.FreeCount()
var freelistPendingN = tx.db.freelist.PendingCount()
- var freelistAlloc = tx.db.freelist.EstimatedWritePageSize()
+ var freelistAlloc = tx.db.freelistReadWriter.EstimatedWritePageSize(tx.db.freelist)
// Remove transaction ref & writer lock.
tx.db.rwtx = nil
diff --git a/tx_check.go b/tx_check.go
index c3ecbb975..b8d3bf555 100644
--- a/tx_check.go
+++ b/tx_check.go
@@ -41,9 +41,7 @@ func (tx *Tx) check(cfg checkConfig, ch chan error) {
// Check if any pages are double freed.
freed := make(map[common.Pgid]bool)
- all := make([]common.Pgid, tx.db.freelist.Count())
- tx.db.freelist.Copyall(all)
- for _, id := range all {
+ for _, id := range tx.db.freelist.List() {
if freed[id] {
ch <- fmt.Errorf("page %d: already freed", id)
}