ensure hashmap init clears maps

internal/freelist/array.go

@@ -101,6 +101,7 @@ func (f *array) mergeSpans(ids common.Pgids) {
 func NewArrayFreelist() Interface {
  a := &array{
  shared: newShared(),
+ ids: []common.Pgid{},
  }
  a.Interface = a
  return a

internal/freelist/freelist_test.go

@@ -8,6 +8,8 @@ import (
  "testing"
  "unsafe"
 
+ "github.com/stretchr/testify/require"
+
  "go.etcd.io/bbolt/internal/common"
 )
 
@@ -85,7 +87,7 @@ func TestFreelist_releaseRange(t *testing.T) {
  title: "Single pending outsize minimum end range",
  pagesIn: []testPage{{id: 3, n: 1, allocTxn: 100, freeTxn: 200}},
  releaseRanges: []testRange{{1, 199}},
- wantFree: nil,
+ wantFree: []common.Pgid{},
  },
  {
  title: "Single pending with minimum begin range",
@@ -97,7 +99,7 @@ func TestFreelist_releaseRange(t *testing.T) {
  title: "Single pending outside minimum begin range",
  pagesIn: []testPage{{id: 3, n: 1, allocTxn: 100, freeTxn: 200}},
  releaseRanges: []testRange{{101, 300}},
- wantFree: nil,
+ wantFree: []common.Pgid{},
  },
  {
  title: "Single pending in minimum range",
@@ -109,7 +111,7 @@ func TestFreelist_releaseRange(t *testing.T) {
  title: "Single pending and read transaction at 199",
  pagesIn: []testPage{{id: 3, n: 1, allocTxn: 199, freeTxn: 200}},
  releaseRanges: []testRange{{100, 198}, {200, 300}},
- wantFree: nil,
+ wantFree: []common.Pgid{},
  },
  {
  title: "Adjacent pending and read transactions at 199, 200",
@@ -122,7 +124,7 @@ func TestFreelist_releaseRange(t *testing.T) {
  {200, 199}, // Simulate the ranges db.freePages might produce.
  {201, 300},
  },
- wantFree: nil,
+ wantFree: []common.Pgid{},
  },
  {
  title: "Out of order ranges",
@@ -135,7 +137,7 @@ func TestFreelist_releaseRange(t *testing.T) {
  {201, 200},
  {200, 200},
  },
- wantFree: nil,
+ wantFree: []common.Pgid{},
  },
  {
  title: "Multiple pending, read transaction at 150",
@@ -153,32 +155,71 @@ func TestFreelist_releaseRange(t *testing.T) {
  }
 
  for _, c := range releaseRangeTests {
- f := newTestFreelist()
- var ids []common.Pgid
- for _, p := range c.pagesIn {
- for i := uint64(0); i < uint64(p.n); i++ {
- ids = append(ids, common.Pgid(uint64(p.id)+i))
+ t.Run(c.title, func(t *testing.T) {
+ f := newTestFreelist()
+ var ids []common.Pgid
+ for _, p := range c.pagesIn {
+ for i := uint64(0); i < uint64(p.n); i++ {
+ ids = append(ids, common.Pgid(uint64(p.id)+i))
+ }
+ }
+ f.Init(ids)
+ for _, p := range c.pagesIn {
+ f.Allocate(p.allocTxn, p.n)
  }
- }
- f.Init(ids)
- for _, p := range c.pagesIn {
- f.Allocate(p.allocTxn, p.n)
- }
 
- for _, p := range c.pagesIn {
- f.Free(p.freeTxn, common.NewPage(p.id, 0, 0, uint32(p.n-1)))
- }
+  for _, p := range c.pagesIn {
+  f.Free(p.freeTxn, common.NewPage(p.id, 0, 0, uint32(p.n-1)))
+  }
 
- for _, r := range c.releaseRanges {
- f.releaseRange(r.begin, r.end)
- }
+  for _, r := range c.releaseRanges {
+  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)
- }
+ require.Equal(t, common.Pgids(c.wantFree), f.freePageIds())
+ })
  }
 }
 
+func TestFreeList_init(t *testing.T) {
+ buf := make([]byte, 4096)
+ f := newTestFreelist()
+ f.Init(common.Pgids{5, 6, 8})
+
+ p := common.LoadPage(buf)
+ f.Write(p)
+
+ f2 := newTestFreelist()
+ f2.Read(p)
+ require.Equal(t, common.Pgids{5, 6, 8}, f2.freePageIds())
+
+ // When initializing the freelist with an empty list of page ID,
+ // it should reset the freelist page IDs.
+ f2.Init([]common.Pgid{})
+ require.Equal(t, common.Pgids{}, f2.freePageIds())
+}
+
+func TestFreeList_reload(t *testing.T) {
+ buf := make([]byte, 4096)
+ f := newTestFreelist()
+ f.Init(common.Pgids{5, 6, 8})
+
+ p := common.LoadPage(buf)
+ f.Write(p)
+
+ f2 := newTestFreelist()
+ f2.Read(p)
+ require.Equal(t, common.Pgids{5, 6, 8}, f2.freePageIds())
+
+ f2.Free(common.Txid(5), common.NewPage(10, common.LeafPageFlag, 0, 2))
+
+ // reload shouldn't affect the pending list
+ f2.Reload(p)
+
+ require.Equal(t, common.Pgids{5, 6, 8}, f2.freePageIds())
+ require.Equal(t, []common.Pgid{10, 11, 12}, f2.pendingPageIds()[5].ids)
+}
+
 // Ensure that a freelist can deserialize from a freelist page.
 func TestFreelist_read(t *testing.T) {
  // Create a page.
@@ -263,7 +304,7 @@ func Test_freelist_ReadIDs_and_getFreePageIDs(t *testing.T) {
  }
 
  f2 := newTestFreelist()
- var exp2 []common.Pgid
+ exp2 := []common.Pgid{}
  f2.Init(exp2)
 
  if got2 := f2.freePageIds(); !reflect.DeepEqual(got2, common.Pgids(exp2)) {

internal/freelist/hashmap.go

@@ -21,22 +21,22 @@ type hashMap struct {
 }
 
 func (f *hashMap) Init(pgids common.Pgids) {
+ // reset the counter when freelist init
+ f.freePagesCount = 0
+ f.freemaps = make(map[uint64]pidSet)
+ f.forwardMap = make(map[common.Pgid]uint64)
+ f.backwardMap = make(map[common.Pgid]uint64)
+
  if len(pgids) == 0 {
  return
  }
 
- size := uint64(1)
- start := pgids[0]
- // reset the counter when freelist init
- f.freePagesCount = 0
-
  if !sort.SliceIsSorted([]common.Pgid(pgids), func(i, j int) bool { return pgids[i] < pgids[j] }) {
  panic("pgids not sorted")
  }
 
- f.freemaps = make(map[uint64]pidSet)
- f.forwardMap = make(map[common.Pgid]uint64)
- f.backwardMap = make(map[common.Pgid]uint64)
+ size := uint64(1)
+ start := pgids[0]
 
  for i := 1; i < len(pgids); i++ {
  // continuous page
@@ -117,7 +117,7 @@ func (f *hashMap) FreeCount() int {
 func (f *hashMap) freePageIds() common.Pgids {
  count := f.FreeCount()
  if count == 0 {
- return nil
+ return common.Pgids{}
  }
 
  m := make([]common.Pgid, 0, count)

internal/freelist/shared.go

@@ -167,7 +167,7 @@ func (t *shared) releaseRange(begin, end common.Txid) {
  if begin > end {
  return
  }
- var m common.Pgids
+ m := common.Pgids{}
  for tid, txp := range t.pending {
  if tid < begin || tid > end {
  continue