erigon-pulse/swarm/storage/ldbstore_test.go

794 lines
21 KiB
Go

// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package storage
import (
"bytes"
"context"
"encoding/binary"
"fmt"
"io/ioutil"
"os"
"strconv"
"strings"
"testing"
"github.com/ethereum/go-ethereum/common"
ch "github.com/ethereum/go-ethereum/swarm/chunk"
"github.com/ethereum/go-ethereum/swarm/log"
"github.com/ethereum/go-ethereum/swarm/storage/mock/mem"
ldberrors "github.com/syndtr/goleveldb/leveldb/errors"
)
type testDbStore struct {
*LDBStore
dir string
}
func newTestDbStore(mock bool, trusted bool) (*testDbStore, func(), error) {
dir, err := ioutil.TempDir("", "bzz-storage-test")
if err != nil {
return nil, func() {}, err
}
var db *LDBStore
storeparams := NewDefaultStoreParams()
params := NewLDBStoreParams(storeparams, dir)
params.Po = testPoFunc
if mock {
globalStore := mem.NewGlobalStore()
addr := common.HexToAddress("0x5aaeb6053f3e94c9b9a09f33669435e7ef1beaed")
mockStore := globalStore.NewNodeStore(addr)
db, err = NewMockDbStore(params, mockStore)
} else {
db, err = NewLDBStore(params)
}
cleanup := func() {
if db != nil {
db.Close()
}
err = os.RemoveAll(dir)
if err != nil {
panic(fmt.Sprintf("db cleanup failed: %v", err))
}
}
return &testDbStore{db, dir}, cleanup, err
}
func testPoFunc(k Address) (ret uint8) {
basekey := make([]byte, 32)
return uint8(Proximity(basekey, k[:]))
}
func testDbStoreRandom(n int, chunksize int64, mock bool, t *testing.T) {
db, cleanup, err := newTestDbStore(mock, true)
defer cleanup()
if err != nil {
t.Fatalf("init dbStore failed: %v", err)
}
testStoreRandom(db, n, chunksize, t)
}
func testDbStoreCorrect(n int, chunksize int64, mock bool, t *testing.T) {
db, cleanup, err := newTestDbStore(mock, false)
defer cleanup()
if err != nil {
t.Fatalf("init dbStore failed: %v", err)
}
testStoreCorrect(db, n, chunksize, t)
}
func TestMarkAccessed(t *testing.T) {
db, cleanup, err := newTestDbStore(false, true)
defer cleanup()
if err != nil {
t.Fatalf("init dbStore failed: %v", err)
}
h := GenerateRandomChunk(ch.DefaultSize)
db.Put(context.Background(), h)
var index dpaDBIndex
addr := h.Address()
idxk := getIndexKey(addr)
idata, err := db.db.Get(idxk)
if err != nil {
t.Fatal(err)
}
decodeIndex(idata, &index)
if index.Access != 0 {
t.Fatalf("Expected the access index to be %d, but it is %d", 0, index.Access)
}
db.MarkAccessed(addr)
db.writeCurrentBatch()
idata, err = db.db.Get(idxk)
if err != nil {
t.Fatal(err)
}
decodeIndex(idata, &index)
if index.Access != 1 {
t.Fatalf("Expected the access index to be %d, but it is %d", 1, index.Access)
}
}
func TestDbStoreRandom_1(t *testing.T) {
testDbStoreRandom(1, 0, false, t)
}
func TestDbStoreCorrect_1(t *testing.T) {
testDbStoreCorrect(1, 4096, false, t)
}
func TestDbStoreRandom_1k(t *testing.T) {
testDbStoreRandom(1000, 0, false, t)
}
func TestDbStoreCorrect_1k(t *testing.T) {
testDbStoreCorrect(1000, 4096, false, t)
}
func TestMockDbStoreRandom_1(t *testing.T) {
testDbStoreRandom(1, 0, true, t)
}
func TestMockDbStoreCorrect_1(t *testing.T) {
testDbStoreCorrect(1, 4096, true, t)
}
func TestMockDbStoreRandom_1k(t *testing.T) {
testDbStoreRandom(1000, 0, true, t)
}
func TestMockDbStoreCorrect_1k(t *testing.T) {
testDbStoreCorrect(1000, 4096, true, t)
}
func testDbStoreNotFound(t *testing.T, mock bool) {
db, cleanup, err := newTestDbStore(mock, false)
defer cleanup()
if err != nil {
t.Fatalf("init dbStore failed: %v", err)
}
_, err = db.Get(context.TODO(), ZeroAddr)
if err != ErrChunkNotFound {
t.Errorf("Expected ErrChunkNotFound, got %v", err)
}
}
func TestDbStoreNotFound(t *testing.T) {
testDbStoreNotFound(t, false)
}
func TestMockDbStoreNotFound(t *testing.T) {
testDbStoreNotFound(t, true)
}
func testIterator(t *testing.T, mock bool) {
var chunkcount int = 32
var i int
var poc uint
chunkkeys := NewAddressCollection(chunkcount)
chunkkeys_results := NewAddressCollection(chunkcount)
db, cleanup, err := newTestDbStore(mock, false)
defer cleanup()
if err != nil {
t.Fatalf("init dbStore failed: %v", err)
}
chunks := GenerateRandomChunks(ch.DefaultSize, chunkcount)
for i = 0; i < len(chunks); i++ {
chunkkeys[i] = chunks[i].Address()
err := db.Put(context.TODO(), chunks[i])
if err != nil {
t.Fatalf("dbStore.Put failed: %v", err)
}
}
for i = 0; i < len(chunkkeys); i++ {
log.Trace(fmt.Sprintf("Chunk array pos %d/%d: '%v'", i, chunkcount, chunkkeys[i]))
}
i = 0
for poc = 0; poc <= 255; poc++ {
err := db.SyncIterator(0, uint64(chunkkeys.Len()), uint8(poc), func(k Address, n uint64) bool {
log.Trace(fmt.Sprintf("Got key %v number %d poc %d", k, n, uint8(poc)))
chunkkeys_results[n] = k
i++
return true
})
if err != nil {
t.Fatalf("Iterator call failed: %v", err)
}
}
for i = 0; i < chunkcount; i++ {
if !bytes.Equal(chunkkeys[i], chunkkeys_results[i]) {
t.Fatalf("Chunk put #%d key '%v' does not match iterator's key '%v'", i, chunkkeys[i], chunkkeys_results[i])
}
}
}
func TestIterator(t *testing.T) {
testIterator(t, false)
}
func TestMockIterator(t *testing.T) {
testIterator(t, true)
}
func benchmarkDbStorePut(n int, processors int, chunksize int64, mock bool, b *testing.B) {
db, cleanup, err := newTestDbStore(mock, true)
defer cleanup()
if err != nil {
b.Fatalf("init dbStore failed: %v", err)
}
benchmarkStorePut(db, n, chunksize, b)
}
func benchmarkDbStoreGet(n int, processors int, chunksize int64, mock bool, b *testing.B) {
db, cleanup, err := newTestDbStore(mock, true)
defer cleanup()
if err != nil {
b.Fatalf("init dbStore failed: %v", err)
}
benchmarkStoreGet(db, n, chunksize, b)
}
func BenchmarkDbStorePut_1_500(b *testing.B) {
benchmarkDbStorePut(500, 1, 4096, false, b)
}
func BenchmarkDbStorePut_8_500(b *testing.B) {
benchmarkDbStorePut(500, 8, 4096, false, b)
}
func BenchmarkDbStoreGet_1_500(b *testing.B) {
benchmarkDbStoreGet(500, 1, 4096, false, b)
}
func BenchmarkDbStoreGet_8_500(b *testing.B) {
benchmarkDbStoreGet(500, 8, 4096, false, b)
}
func BenchmarkMockDbStorePut_1_500(b *testing.B) {
benchmarkDbStorePut(500, 1, 4096, true, b)
}
func BenchmarkMockDbStorePut_8_500(b *testing.B) {
benchmarkDbStorePut(500, 8, 4096, true, b)
}
func BenchmarkMockDbStoreGet_1_500(b *testing.B) {
benchmarkDbStoreGet(500, 1, 4096, true, b)
}
func BenchmarkMockDbStoreGet_8_500(b *testing.B) {
benchmarkDbStoreGet(500, 8, 4096, true, b)
}
// TestLDBStoreWithoutCollectGarbage tests that we can put a number of random chunks in the LevelDB store, and
// retrieve them, provided we don't hit the garbage collection
func TestLDBStoreWithoutCollectGarbage(t *testing.T) {
capacity := 50
n := 10
ldb, cleanup := newLDBStore(t)
ldb.setCapacity(uint64(capacity))
defer cleanup()
chunks, err := mputRandomChunks(ldb, n, int64(ch.DefaultSize))
if err != nil {
t.Fatal(err.Error())
}
log.Info("ldbstore", "entrycnt", ldb.entryCnt, "accesscnt", ldb.accessCnt)
for _, ch := range chunks {
ret, err := ldb.Get(context.TODO(), ch.Address())
if err != nil {
t.Fatal(err)
}
if !bytes.Equal(ret.Data(), ch.Data()) {
t.Fatal("expected to get the same data back, but got smth else")
}
}
if ldb.entryCnt != uint64(n) {
t.Fatalf("expected entryCnt to be equal to %v, but got %v", n, ldb.entryCnt)
}
if ldb.accessCnt != uint64(2*n) {
t.Fatalf("expected accessCnt to be equal to %v, but got %v", 2*n, ldb.accessCnt)
}
}
// TestLDBStoreCollectGarbage tests that we can put more chunks than LevelDB's capacity, and
// retrieve only some of them, because garbage collection must have partially cleared the store
// Also tests that we can delete chunks and that we can trigger garbage collection
func TestLDBStoreCollectGarbage(t *testing.T) {
// below max ronud
initialCap := defaultMaxGCRound / 100
cap := initialCap / 2
t.Run(fmt.Sprintf("A/%d/%d", cap, cap*4), testLDBStoreCollectGarbage)
t.Run(fmt.Sprintf("B/%d/%d", cap, cap*4), testLDBStoreRemoveThenCollectGarbage)
// at max round
cap = initialCap
t.Run(fmt.Sprintf("A/%d/%d", cap, cap*4), testLDBStoreCollectGarbage)
t.Run(fmt.Sprintf("B/%d/%d", cap, cap*4), testLDBStoreRemoveThenCollectGarbage)
// more than max around, not on threshold
cap = initialCap + 500
t.Run(fmt.Sprintf("A/%d/%d", cap, cap*4), testLDBStoreCollectGarbage)
t.Run(fmt.Sprintf("B/%d/%d", cap, cap*4), testLDBStoreRemoveThenCollectGarbage)
}
func testLDBStoreCollectGarbage(t *testing.T) {
params := strings.Split(t.Name(), "/")
capacity, err := strconv.Atoi(params[2])
if err != nil {
t.Fatal(err)
}
n, err := strconv.Atoi(params[3])
if err != nil {
t.Fatal(err)
}
ldb, cleanup := newLDBStore(t)
ldb.setCapacity(uint64(capacity))
defer cleanup()
// retrieve the gc round target count for the db capacity
ldb.startGC(capacity)
roundTarget := ldb.gc.target
// split put counts to gc target count threshold, and wait for gc to finish in between
var allChunks []Chunk
remaining := n
for remaining > 0 {
var putCount int
if remaining < roundTarget {
putCount = remaining
} else {
putCount = roundTarget
}
remaining -= putCount
chunks, err := mputRandomChunks(ldb, putCount, int64(ch.DefaultSize))
if err != nil {
t.Fatal(err.Error())
}
allChunks = append(allChunks, chunks...)
ldb.lock.RLock()
log.Debug("ldbstore", "entrycnt", ldb.entryCnt, "accesscnt", ldb.accessCnt, "cap", capacity, "n", n)
ldb.lock.RUnlock()
waitGc(ldb)
}
// attempt gets on all put chunks
var missing int
for _, ch := range allChunks {
ret, err := ldb.Get(context.TODO(), ch.Address())
if err == ErrChunkNotFound || err == ldberrors.ErrNotFound {
missing++
continue
}
if err != nil {
t.Fatal(err)
}
if !bytes.Equal(ret.Data(), ch.Data()) {
t.Fatal("expected to get the same data back, but got smth else")
}
log.Trace("got back chunk", "chunk", ret)
}
// all surplus chunks should be missing
expectMissing := roundTarget + (((n - capacity) / roundTarget) * roundTarget)
if missing != expectMissing {
t.Fatalf("gc failure: expected to miss %v chunks, but only %v are actually missing", expectMissing, missing)
}
log.Info("ldbstore", "total", n, "missing", missing, "entrycnt", ldb.entryCnt, "accesscnt", ldb.accessCnt)
}
// TestLDBStoreAddRemove tests that we can put and then delete a given chunk
func TestLDBStoreAddRemove(t *testing.T) {
ldb, cleanup := newLDBStore(t)
ldb.setCapacity(200)
defer cleanup()
n := 100
chunks, err := mputRandomChunks(ldb, n, int64(ch.DefaultSize))
if err != nil {
t.Fatalf(err.Error())
}
for i := 0; i < n; i++ {
// delete all even index chunks
if i%2 == 0 {
ldb.Delete(chunks[i].Address())
}
}
log.Info("ldbstore", "entrycnt", ldb.entryCnt, "accesscnt", ldb.accessCnt)
for i := 0; i < n; i++ {
ret, err := ldb.Get(context.TODO(), chunks[i].Address())
if i%2 == 0 {
// expect even chunks to be missing
if err == nil {
t.Fatal("expected chunk to be missing, but got no error")
}
} else {
// expect odd chunks to be retrieved successfully
if err != nil {
t.Fatalf("expected no error, but got %s", err)
}
if !bytes.Equal(ret.Data(), chunks[i].Data()) {
t.Fatal("expected to get the same data back, but got smth else")
}
}
}
}
func testLDBStoreRemoveThenCollectGarbage(t *testing.T) {
t.Skip("flaky with -race flag")
params := strings.Split(t.Name(), "/")
capacity, err := strconv.Atoi(params[2])
if err != nil {
t.Fatal(err)
}
n, err := strconv.Atoi(params[3])
if err != nil {
t.Fatal(err)
}
ldb, cleanup := newLDBStore(t)
defer cleanup()
ldb.setCapacity(uint64(capacity))
// put capacity count number of chunks
chunks := make([]Chunk, n)
for i := 0; i < n; i++ {
c := GenerateRandomChunk(ch.DefaultSize)
chunks[i] = c
log.Trace("generate random chunk", "idx", i, "chunk", c)
}
for i := 0; i < n; i++ {
err := ldb.Put(context.TODO(), chunks[i])
if err != nil {
t.Fatal(err)
}
}
waitGc(ldb)
// delete all chunks
// (only count the ones actually deleted, the rest will have been gc'd)
deletes := 0
for i := 0; i < n; i++ {
if ldb.Delete(chunks[i].Address()) == nil {
deletes++
}
}
log.Info("ldbstore", "entrycnt", ldb.entryCnt, "accesscnt", ldb.accessCnt)
if ldb.entryCnt != 0 {
t.Fatalf("ldb.entrCnt expected 0 got %v", ldb.entryCnt)
}
// the manual deletes will have increased accesscnt, so we need to add this when we verify the current count
expAccessCnt := uint64(n)
if ldb.accessCnt != expAccessCnt {
t.Fatalf("ldb.accessCnt expected %v got %v", expAccessCnt, ldb.accessCnt)
}
// retrieve the gc round target count for the db capacity
ldb.startGC(capacity)
roundTarget := ldb.gc.target
remaining := n
var puts int
for remaining > 0 {
var putCount int
if remaining < roundTarget {
putCount = remaining
} else {
putCount = roundTarget
}
remaining -= putCount
for putCount > 0 {
ldb.Put(context.TODO(), chunks[puts])
ldb.lock.RLock()
log.Debug("ldbstore", "entrycnt", ldb.entryCnt, "accesscnt", ldb.accessCnt, "cap", capacity, "n", n, "puts", puts, "remaining", remaining, "roundtarget", roundTarget)
ldb.lock.RUnlock()
puts++
putCount--
}
waitGc(ldb)
}
// expect first surplus chunks to be missing, because they have the smallest access value
expectMissing := roundTarget + (((n - capacity) / roundTarget) * roundTarget)
for i := 0; i < expectMissing; i++ {
_, err := ldb.Get(context.TODO(), chunks[i].Address())
if err == nil {
t.Fatalf("expected surplus chunk %d to be missing, but got no error", i)
}
}
// expect last chunks to be present, as they have the largest access value
for i := expectMissing; i < n; i++ {
ret, err := ldb.Get(context.TODO(), chunks[i].Address())
if err != nil {
t.Fatalf("chunk %v: expected no error, but got %s", i, err)
}
if !bytes.Equal(ret.Data(), chunks[i].Data()) {
t.Fatal("expected to get the same data back, but got smth else")
}
}
}
// TestLDBStoreCollectGarbageAccessUnlikeIndex tests garbage collection where accesscount differs from indexcount
func TestLDBStoreCollectGarbageAccessUnlikeIndex(t *testing.T) {
capacity := defaultMaxGCRound / 100 * 2
n := capacity - 1
ldb, cleanup := newLDBStore(t)
ldb.setCapacity(uint64(capacity))
defer cleanup()
chunks, err := mputRandomChunks(ldb, n, int64(ch.DefaultSize))
if err != nil {
t.Fatal(err.Error())
}
log.Info("ldbstore", "entrycnt", ldb.entryCnt, "accesscnt", ldb.accessCnt)
// set first added capacity/2 chunks to highest accesscount
for i := 0; i < capacity/2; i++ {
_, err := ldb.Get(context.TODO(), chunks[i].Address())
if err != nil {
t.Fatalf("fail add chunk #%d - %s: %v", i, chunks[i].Address(), err)
}
}
_, err = mputRandomChunks(ldb, 2, int64(ch.DefaultSize))
if err != nil {
t.Fatal(err.Error())
}
// wait for garbage collection to kick in on the responsible actor
waitGc(ldb)
var missing int
for i, ch := range chunks[2 : capacity/2] {
ret, err := ldb.Get(context.TODO(), ch.Address())
if err == ErrChunkNotFound || err == ldberrors.ErrNotFound {
t.Fatalf("fail find chunk #%d - %s: %v", i, ch.Address(), err)
}
if !bytes.Equal(ret.Data(), ch.Data()) {
t.Fatal("expected to get the same data back, but got smth else")
}
log.Trace("got back chunk", "chunk", ret)
}
log.Info("ldbstore", "total", n, "missing", missing, "entrycnt", ldb.entryCnt, "accesscnt", ldb.accessCnt)
}
func TestCleanIndex(t *testing.T) {
capacity := 5000
n := 3
ldb, cleanup := newLDBStore(t)
ldb.setCapacity(uint64(capacity))
defer cleanup()
chunks, err := mputRandomChunks(ldb, n, 4096)
if err != nil {
t.Fatal(err)
}
// remove the data of the first chunk
po := ldb.po(chunks[0].Address()[:])
dataKey := make([]byte, 10)
dataKey[0] = keyData
dataKey[1] = byte(po)
// dataKey[2:10] = first chunk has storageIdx 0 on [2:10]
if _, err := ldb.db.Get(dataKey); err != nil {
t.Fatal(err)
}
if err := ldb.db.Delete(dataKey); err != nil {
t.Fatal(err)
}
// remove the gc index row for the first chunk
gcFirstCorrectKey := make([]byte, 9)
gcFirstCorrectKey[0] = keyGCIdx
if err := ldb.db.Delete(gcFirstCorrectKey); err != nil {
t.Fatal(err)
}
// warp the gc data of the second chunk
// this data should be correct again after the clean
gcSecondCorrectKey := make([]byte, 9)
gcSecondCorrectKey[0] = keyGCIdx
binary.BigEndian.PutUint64(gcSecondCorrectKey[1:], uint64(1))
gcSecondCorrectVal, err := ldb.db.Get(gcSecondCorrectKey)
if err != nil {
t.Fatal(err)
}
warpedGCVal := make([]byte, len(gcSecondCorrectVal)+1)
copy(warpedGCVal[1:], gcSecondCorrectVal)
if err := ldb.db.Delete(gcSecondCorrectKey); err != nil {
t.Fatal(err)
}
if err := ldb.db.Put(gcSecondCorrectKey, warpedGCVal); err != nil {
t.Fatal(err)
}
if err := ldb.CleanGCIndex(); err != nil {
t.Fatal(err)
}
// the index without corresponding data should have been deleted
idxKey := make([]byte, 33)
idxKey[0] = keyIndex
copy(idxKey[1:], chunks[0].Address())
if _, err := ldb.db.Get(idxKey); err == nil {
t.Fatalf("expected chunk 0 idx to be pruned: %v", idxKey)
}
// the two other indices should be present
copy(idxKey[1:], chunks[1].Address())
if _, err := ldb.db.Get(idxKey); err != nil {
t.Fatalf("expected chunk 1 idx to be present: %v", idxKey)
}
copy(idxKey[1:], chunks[2].Address())
if _, err := ldb.db.Get(idxKey); err != nil {
t.Fatalf("expected chunk 2 idx to be present: %v", idxKey)
}
// first gc index should still be gone
if _, err := ldb.db.Get(gcFirstCorrectKey); err == nil {
t.Fatalf("expected gc 0 idx to be pruned: %v", idxKey)
}
// second gc index should still be fixed
if _, err := ldb.db.Get(gcSecondCorrectKey); err != nil {
t.Fatalf("expected gc 1 idx to be present: %v", idxKey)
}
// third gc index should be unchanged
binary.BigEndian.PutUint64(gcSecondCorrectKey[1:], uint64(2))
if _, err := ldb.db.Get(gcSecondCorrectKey); err != nil {
t.Fatalf("expected gc 2 idx to be present: %v", idxKey)
}
c, err := ldb.db.Get(keyEntryCnt)
if err != nil {
t.Fatalf("expected gc 2 idx to be present: %v", idxKey)
}
// entrycount should now be one less
entryCount := binary.BigEndian.Uint64(c)
if entryCount != 2 {
t.Fatalf("expected entrycnt to be 2, was %d", c)
}
// the chunks might accidentally be in the same bin
// if so that bin counter will now be 2 - the highest added index.
// if not, the total of them will be 3
poBins := []uint8{ldb.po(chunks[1].Address()), ldb.po(chunks[2].Address())}
if poBins[0] == poBins[1] {
poBins = poBins[:1]
}
var binTotal uint64
var currentBin [2]byte
currentBin[0] = keyDistanceCnt
if len(poBins) == 1 {
currentBin[1] = poBins[0]
c, err := ldb.db.Get(currentBin[:])
if err != nil {
t.Fatalf("expected gc 2 idx to be present: %v", idxKey)
}
binCount := binary.BigEndian.Uint64(c)
if binCount != 2 {
t.Fatalf("expected entrycnt to be 2, was %d", binCount)
}
} else {
for _, bin := range poBins {
currentBin[1] = bin
c, err := ldb.db.Get(currentBin[:])
if err != nil {
t.Fatalf("expected gc 2 idx to be present: %v", idxKey)
}
binCount := binary.BigEndian.Uint64(c)
binTotal += binCount
}
if binTotal != 3 {
t.Fatalf("expected sum of bin indices to be 3, was %d", binTotal)
}
}
// check that the iterator quits properly
chunks, err = mputRandomChunks(ldb, 4100, 4096)
if err != nil {
t.Fatal(err)
}
po = ldb.po(chunks[4099].Address()[:])
dataKey = make([]byte, 10)
dataKey[0] = keyData
dataKey[1] = byte(po)
binary.BigEndian.PutUint64(dataKey[2:], 4099+3)
if _, err := ldb.db.Get(dataKey); err != nil {
t.Fatal(err)
}
if err := ldb.db.Delete(dataKey); err != nil {
t.Fatal(err)
}
if err := ldb.CleanGCIndex(); err != nil {
t.Fatal(err)
}
// entrycount should now be one less of added chunks
c, err = ldb.db.Get(keyEntryCnt)
if err != nil {
t.Fatalf("expected gc 2 idx to be present: %v", idxKey)
}
entryCount = binary.BigEndian.Uint64(c)
if entryCount != 4099+2 {
t.Fatalf("expected entrycnt to be 2, was %d", c)
}
}
// Note: waitGc does not guarantee that we wait 1 GC round; it only
// guarantees that if the GC is running we wait for that run to finish
// ticket: https://github.com/ethersphere/go-ethereum/issues/1151
func waitGc(ldb *LDBStore) {
<-ldb.gc.runC
ldb.gc.runC <- struct{}{}
}