// mine generates a testnet struct literal with nodes at
// various distances to the given target.
func (n *preminedTestnet) mine(target NodeID) {
n.target = target
n.targetSha = crypto.Keccak256Hash(n.target[:])
found := 0
for found < bucketSize*10 {
k := newkey()
id := PubkeyID(&k.PublicKey)
sha := crypto.Keccak256Hash(id[:])
ld := logdist(n.targetSha, sha)
if len(n.dists[ld]) < bucketSize {
n.dists[ld] = append(n.dists[ld], id)
fmt.Println("found ID with ld", ld)
found++
}
}
fmt.Println("&preminedTestnet{")
fmt.Printf(" target: %#v,\n", n.target)
fmt.Printf(" targetSha: %#v,\n", n.targetSha)
fmt.Printf(" dists: [%d][]NodeID{\n", len(n.dists))
for ld, ns := range n.dists {
if len(ns) == 0 {
continue
}
fmt.Printf(" %d: []NodeID{\n", ld)
for _, n := range ns {
fmt.Printf(" MustHexID(\"%x\"),\n", n[:])
}
fmt.Println(" },")
}
fmt.Println(" },")
fmt.Println("}")
}
func TestEventId(t *testing.T) {
var table = []struct {
definition string
expectations map[string]common.Hash
}{
{
definition: `[
{ "type" : "event", "name" : "balance", "inputs": [{ "name" : "in", "type": "uint" }] },
{ "type" : "event", "name" : "check", "inputs": [{ "name" : "t", "type": "address" }, { "name": "b", "type": "uint256" }] }
]`,
expectations: map[string]common.Hash{
"balance": crypto.Keccak256Hash([]byte("balance(uint256)")),
"check": crypto.Keccak256Hash([]byte("check(address,uint256)")),
},
},
}
for _, test := range table {
abi, err := JSON(strings.NewReader(test.definition))
if err != nil {
t.Fatal(err)
}
for name, event := range abi.Events {
if event.Id() != test.expectations[name] {
t.Errorf("expected id to be %x, got %x", test.expectations[name], event.Id())
}
}
}
}
func TestGetAuthContent(t *testing.T) {
dir, err := ioutil.TempDir("", "httpclient-test")
if err != nil {
t.Fatal("cannot create temporary directory:", err)
}
defer os.RemoveAll(dir)
client := New(dir)
text := "test"
hash := crypto.Keccak256Hash([]byte(text))
if err := ioutil.WriteFile(path.Join(dir, "test.content"), []byte(text), os.ModePerm); err != nil {
t.Fatal("could not write test file", err)
}
content, err := client.GetAuthContent("file:///test.content", hash)
if err != nil {
t.Errorf("no error expected, got %v", err)
}
if string(content) != text {
t.Errorf("incorrect content. expected %v, got %v", text, string(content))
}
hash = common.Hash{}
content, err = client.GetAuthContent("file:///test.content", hash)
expected := "content hash mismatch 0000000000000000000000000000000000000000000000000000000000000000 != 9c22ff5f21f0b81b113e63f7db6da94fedef11b2119b4088b89664fb9a3cb658 (exp)"
if err == nil {
t.Errorf("expected error, got nothing")
} else {
if err.Error() != expected {
t.Errorf("expected error '%s' got '%v'", expected, err)
}
}
}
func (req *findnode) handle(t *udp, from *net.UDPAddr, fromID NodeID, mac []byte) error {
if expired(req.Expiration) {
return errExpired
}
if t.db.node(fromID) == nil {
// No bond exists, we don't process the packet. This prevents
// an attack vector where the discovery protocol could be used
// to amplify traffic in a DDOS attack. A malicious actor
// would send a findnode request with the IP address and UDP
// port of the target as the source address. The recipient of
// the findnode packet would then send a neighbors packet
// (which is a much bigger packet than findnode) to the victim.
return errUnknownNode
}
target := crypto.Keccak256Hash(req.Target[:])
t.mutex.Lock()
closest := t.closest(target, bucketSize).entries
t.mutex.Unlock()
p := neighbors{Expiration: uint64(time.Now().Add(expiration).Unix())}
// Send neighbors in chunks with at most maxNeighbors per packet
// to stay below the 1280 byte limit.
for i, n := range closest {
p.Nodes = append(p.Nodes, nodeToRPC(n))
if len(p.Nodes) == maxNeighbors || i == len(closest)-1 {
t.send(from, neighborsPacket, p)
p.Nodes = p.Nodes[:0]
}
}
return nil
}
// Hash returns the SHA3 hash of the envelope, calculating it if not yet done.
func (self *Envelope) Hash() common.Hash {
if (self.hash == common.Hash{}) {
enc, _ := rlp.EncodeToBytes(self)
self.hash = crypto.Keccak256Hash(enc)
}
return self.hash
}
// NewProgram returns a new JIT program
func NewProgram(code []byte) *Program {
program := &Program{
Id: crypto.Keccak256Hash(code),
mapping: make(map[uint64]uint64),
destinations: make(map[uint64]struct{}),
code: code,
}
programs.Add(program.Id, program)
return program
}
// NewNode creates a new node. It is mostly meant to be used for
// testing purposes.
func NewNode(id NodeID, ip net.IP, udpPort, tcpPort uint16) *Node {
if ipv4 := ip.To4(); ipv4 != nil {
ip = ipv4
}
return &Node{
IP: ip,
UDP: udpPort,
TCP: tcpPort,
ID: id,
sha: crypto.Keccak256Hash(id[:]),
}
}
// node retrieves a node with a given id from the database.
func (db *nodeDB) node(id NodeID) *Node {
blob, err := db.lvl.Get(makeKey(id, nodeDBDiscoverRoot), nil)
if err != nil {
glog.V(logger.Detail).Infof("failed to retrieve node %v: %v", id, err)
return nil
}
node := new(Node)
if err := rlp.DecodeBytes(blob, node); err != nil {
glog.V(logger.Warn).Infof("failed to decode node RLP: %v", err)
return nil
}
node.sha = crypto.Keccak256Hash(node.ID[:])
return node
}
func (self *HTTPClient) GetAuthContent(uri string, hash common.Hash) ([]byte, error) {
// retrieve content
content, err := self.Get(uri, "")
if err != nil {
return nil, err
}
// check hash to authenticate content
chash := crypto.Keccak256Hash(content)
if chash != hash {
return nil, fmt.Errorf("content hash mismatch %x != %x (exp)", hash[:], chash[:])
}
return content, nil
}
// DecodeRLP decodes an Envelope from an RLP data stream.
func (self *Envelope) DecodeRLP(s *rlp.Stream) error {
raw, err := s.Raw()
if err != nil {
return err
}
// The decoding of Envelope uses the struct fields but also needs
// to compute the hash of the whole RLP-encoded envelope. This
// type has the same structure as Envelope but is not an
// rlp.Decoder so we can reuse the Envelope struct definition.
type rlpenv Envelope
if err := rlp.DecodeBytes(raw, (*rlpenv)(self)); err != nil {
return err
}
self.hash = crypto.Keccak256Hash(raw)
return nil
}
// Resolve searches for a specific node with the given ID.
// It returns nil if the node could not be found.
func (tab *Table) Resolve(targetID NodeID) *Node {
// If the node is present in the local table, no
// network interaction is required.
hash := crypto.Keccak256Hash(targetID[:])
tab.mutex.Lock()
cl := tab.closest(hash, 1)
tab.mutex.Unlock()
if len(cl.entries) > 0 && cl.entries[0].ID == targetID {
return cl.entries[0]
}
// Otherwise, do a network lookup.
result := tab.Lookup(targetID)
for _, n := range result {
if n.ID == targetID {
return n
}
}
return nil
}
// SetFallbackNodes sets the initial points of contact. These nodes
// are used to connect to the network if the table is empty and there
// are no known nodes in the database.
func (tab *Table) SetFallbackNodes(nodes []*Node) error {
for _, n := range nodes {
if err := n.validateComplete(); err != nil {
return fmt.Errorf("bad bootstrap/fallback node %q (%v)", n, err)
}
}
tab.mutex.Lock()
tab.nursery = make([]*Node, 0, len(nodes))
for _, n := range nodes {
cpy := *n
// Recompute cpy.sha because the node might not have been
// created by NewNode or ParseNode.
cpy.sha = crypto.Keccak256Hash(n.ID[:])
tab.nursery = append(tab.nursery, &cpy)
}
tab.mutex.Unlock()
tab.refresh()
return nil
}
func TestUDP_findnode(t *testing.T) {
test := newUDPTest(t)
defer test.table.Close()
// put a few nodes into the table. their exact
// distribution shouldn't matter much, altough we need to
// take care not to overflow any bucket.
targetHash := crypto.Keccak256Hash(testTarget[:])
nodes := &nodesByDistance{target: targetHash}
for i := 0; i < bucketSize; i++ {
nodes.push(nodeAtDistance(test.table.self.sha, i+2), bucketSize)
}
test.table.stuff(nodes.entries)
// ensure there's a bond with the test node,
// findnode won't be accepted otherwise.
test.table.db.updateNode(NewNode(
PubkeyID(&test.remotekey.PublicKey),
test.remoteaddr.IP,
uint16(test.remoteaddr.Port),
99,
))
// check that closest neighbors are returned.
test.packetIn(nil, findnodePacket, &findnode{Target: testTarget, Expiration: futureExp})
expected := test.table.closest(targetHash, bucketSize)
waitNeighbors := func(want []*Node) {
test.waitPacketOut(func(p *neighbors) {
if len(p.Nodes) != len(want) {
t.Errorf("wrong number of results: got %d, want %d", len(p.Nodes), bucketSize)
}
for i := range p.Nodes {
if p.Nodes[i].ID != want[i].ID {
t.Errorf("result mismatch at %d:\n got: %v\n want: %v", i, p.Nodes[i], expected.entries[i])
}
}
})
}
waitNeighbors(expected.entries[:maxNeighbors])
waitNeighbors(expected.entries[maxNeighbors:])
}
// Run loops and evaluates the contract's code with the given input data
func (evm *EVM) Run(contract *Contract, input []byte) (ret []byte, err error) {
evm.env.SetDepth(evm.env.Depth() + 1)
defer evm.env.SetDepth(evm.env.Depth() - 1)
if contract.CodeAddr != nil {
if p := Precompiled[contract.CodeAddr.Str()]; p != nil {
return evm.RunPrecompiled(p, input, contract)
}
}
// Don't bother with the execution if there's no code.
if len(contract.Code) == 0 {
return nil, nil
}
var (
codehash = crypto.Keccak256Hash(contract.Code) // codehash is used when doing jump dest caching
program *Program
)
if evm.cfg.EnableJit {
// If the JIT is enabled check the status of the JIT program,
// if it doesn't exist compile a new program in a separate
// goroutine or wait for compilation to finish if the JIT is
// forced.
switch GetProgramStatus(codehash) {
case progReady:
return RunProgram(GetProgram(codehash), evm.env, contract, input)
case progUnknown:
if evm.cfg.ForceJit {
// Create and compile program
program = NewProgram(contract.Code)
perr := CompileProgram(program)
if perr == nil {
return RunProgram(program, evm.env, contract, input)
}
glog.V(logger.Info).Infoln("error compiling program", err)
} else {
// create and compile the program. Compilation
// is done in a separate goroutine
program = NewProgram(contract.Code)
go func() {
err := CompileProgram(program)
if err != nil {
glog.V(logger.Info).Infoln("error compiling program", err)
return
}
}()
}
}
}
var (
caller = contract.caller
code = contract.Code
instrCount = 0
op OpCode // current opcode
mem = NewMemory() // bound memory
stack = newstack() // local stack
statedb = evm.env.Db() // current state
// For optimisation reason we're using uint64 as the program counter.
// It's theoretically possible to go above 2^64. The YP defines the PC to be uint256. Practically much less so feasible.
pc = uint64(0) // program counter
// jump evaluates and checks whether the given jump destination is a valid one
// if valid move the `pc` otherwise return an error.
jump = func(from uint64, to *big.Int) error {
if !contract.jumpdests.has(codehash, code, to) {
nop := contract.GetOp(to.Uint64())
return fmt.Errorf("invalid jump destination (%v) %v", nop, to)
}
pc = to.Uint64()
return nil
}
newMemSize *big.Int
cost *big.Int
)
contract.Input = input
// User defer pattern to check for an error and, based on the error being nil or not, use all gas and return.
defer func() {
if err != nil && evm.cfg.Debug {
evm.logger.captureState(pc, op, contract.Gas, cost, mem, stack, contract, err)
}
}()
if glog.V(logger.Debug) {
glog.Infof("running byte VM %x\n", codehash[:4])
tstart := time.Now()
defer func() {
glog.Infof("byte VM %x done. time: %v instrc: %v\n", codehash[:4], time.Since(tstart), instrCount)
}()
}
for ; ; instrCount++ {
/*
if EnableJit && it%100 == 0 {
if program != nil && progStatus(atomic.LoadInt32(&program.status)) == progReady {
// move execution
fmt.Println("moved", it)
glog.V(logger.Info).Infoln("Moved execution to JIT")
return runProgram(program, pc, mem, stack, evm.env, contract, input)
}
}
*/
// Get the memory location of pc
op = contract.GetOp(pc)
// calculate the new memory size and gas price for the current executing opcode
newMemSize, cost, err = calculateGasAndSize(evm.env, contract, caller, op, statedb, mem, stack)
if err != nil {
return nil, err
}
// Use the calculated gas. When insufficient gas is present, use all gas and return an
// Out Of Gas error
if !contract.UseGas(cost) {
return nil, OutOfGasError
}
// Resize the memory calculated previously
mem.Resize(newMemSize.Uint64())
// Add a log message
if evm.cfg.Debug {
evm.logger.captureState(pc, op, contract.Gas, cost, mem, stack, contract, nil)
}
if opPtr := evm.jumpTable[op]; opPtr.valid {
if opPtr.fn != nil {
opPtr.fn(instruction{}, &pc, evm.env, contract, mem, stack)
} else {
switch op {
case PC:
opPc(instruction{data: new(big.Int).SetUint64(pc)}, &pc, evm.env, contract, mem, stack)
case JUMP:
if err := jump(pc, stack.pop()); err != nil {
return nil, err
}
continue
case JUMPI:
pos, cond := stack.pop(), stack.pop()
if cond.Cmp(common.BigTrue) >= 0 {
if err := jump(pc, pos); err != nil {
return nil, err
}
continue
}
case RETURN:
offset, size := stack.pop(), stack.pop()
ret := mem.GetPtr(offset.Int64(), size.Int64())
return ret, nil
case SUICIDE:
opSuicide(instruction{}, nil, evm.env, contract, mem, stack)
fallthrough
case STOP: // Stop the contract
return nil, nil
}
}
} else {
return nil, fmt.Errorf("Invalid opcode %x", op)
}
pc++
}
}
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/ethereum/go-ethereum/rlp"
)
const defaultCacheCapacity = 800
var (
// The global cache stores decoded trie nodes by hash as they get loaded.
globalCache = newARC(defaultCacheCapacity)
// This is the known root hash of an empty trie.
emptyRoot = common.HexToHash("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421")
// This is the known hash of an empty state trie entry.
emptyState = crypto.Keccak256Hash(nil)
)
// ClearGlobalCache clears the global trie cache
func ClearGlobalCache() {
globalCache.Clear()
}
// Database must be implemented by backing stores for the trie.
type Database interface {
DatabaseWriter
// Get returns the value for key from the database.
Get(key []byte) (value []byte, err error)
}
// DatabaseWriter wraps the Put method of a backing store for the trie.
// end to end test
func TestNatspecE2E(t *testing.T) {
t.Skip()
tf := testInit(t)
defer tf.ethereum.Stop()
addr, _ := tf.ethereum.Etherbase()
// create a contractInfo file (mock cloud-deployed contract metadocs)
// incidentally this is the info for the HashReg contract itself
ioutil.WriteFile("/tmp/"+testFileName, []byte(testContractInfo), os.ModePerm)
dochash := crypto.Keccak256Hash([]byte(testContractInfo))
// take the codehash for the contract we wanna test
codeb := tf.xeth.CodeAtBytes(registrar.HashRegAddr)
codehash := crypto.Keccak256Hash(codeb)
reg := registrar.New(tf.xeth)
_, err := reg.SetHashToHash(addr, codehash, dochash)
if err != nil {
t.Errorf("error registering: %v", err)
}
_, err = reg.SetUrlToHash(addr, dochash, "file:///"+testFileName)
if err != nil {
t.Errorf("error registering: %v", err)
}
if !processTxs(tf, t, 5) {
return
}
// NatSpec info for register method of HashReg contract installed
// now using the same transactions to check confirm messages
tf.wantNatSpec = true // this is set so now the backend uses natspec confirmation
_, err = reg.SetHashToHash(addr, codehash, dochash)
if err != nil {
t.Errorf("error calling contract registry: %v", err)
}
fmt.Printf("GlobalRegistrar: %v, HashReg: %v, UrlHint: %v\n", registrar.GlobalRegistrarAddr, registrar.HashRegAddr, registrar.UrlHintAddr)
if tf.lastConfirm != testExpNotice {
t.Errorf("Wrong confirm message. expected\n'%v', got\n'%v'", testExpNotice, tf.lastConfirm)
}
// test unknown method
exp := fmt.Sprintf(testExpNotice2, registrar.HashRegAddr)
_, err = reg.SetOwner(addr)
if err != nil {
t.Errorf("error setting owner: %v", err)
}
if tf.lastConfirm != exp {
t.Errorf("Wrong confirm message, expected\n'%v', got\n'%v'", exp, tf.lastConfirm)
}
// test unknown contract
exp = fmt.Sprintf(testExpNotice3, registrar.UrlHintAddr)
_, err = reg.SetUrlToHash(addr, dochash, "file:///test.content")
if err != nil {
t.Errorf("error registering: %v", err)
}
if tf.lastConfirm != exp {
t.Errorf("Wrong confirm message, expected '%v', got '%v'", exp, tf.lastConfirm)
}
}
OdrRequest
hash common.Hash
data []byte
}
// GetData returns the retrieved node data after a successful request
func (req *NodeDataRequest) GetData() []byte {
return req.data
}
// StoreResult stores the retrieved data in local database
func (req *NodeDataRequest) StoreResult(db ethdb.Database) {
db.Put(req.hash[:], req.GetData())
}
var sha3_nil = crypto.Keccak256Hash(nil)
// retrieveNodeData tries to retrieve node data with the given hash from the network
func retrieveNodeData(ctx context.Context, odr OdrBackend, hash common.Hash) ([]byte, error) {
if hash == sha3_nil {
return nil, nil
}
res, _ := odr.Database().Get(hash[:])
if res != nil {
return res, nil
}
r := &NodeDataRequest{hash: hash}
if err := odr.Retrieve(ctx, r); err != nil {
return nil, err
} else {
return r.GetData(), nil
func testGetNodeData(t *testing.T, protocol int) {
// Define three accounts to simulate transactions with
acc1Key, _ := crypto.HexToECDSA("8a1f9a8f95be41cd7ccb6168179afb4504aefe388d1e14474d32c45c72ce7b7a")
acc2Key, _ := crypto.HexToECDSA("49a7b37aa6f6645917e7b807e9d1c00d4fa71f18343b0d4122a4d2df64dd6fee")
acc1Addr := crypto.PubkeyToAddress(acc1Key.PublicKey)
acc2Addr := crypto.PubkeyToAddress(acc2Key.PublicKey)
// Create a chain generator with some simple transactions (blatantly stolen from @fjl/chain_markets_test)
generator := func(i int, block *core.BlockGen) {
switch i {
case 0:
// In block 1, the test bank sends account #1 some ether.
tx, _ := types.NewTransaction(block.TxNonce(testBank.Address), acc1Addr, big.NewInt(10000), params.TxGas, nil, nil).SignECDSA(testBankKey)
block.AddTx(tx)
case 1:
// In block 2, the test bank sends some more ether to account #1.
// acc1Addr passes it on to account #2.
tx1, _ := types.NewTransaction(block.TxNonce(testBank.Address), acc1Addr, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(testBankKey)
tx2, _ := types.NewTransaction(block.TxNonce(acc1Addr), acc2Addr, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(acc1Key)
block.AddTx(tx1)
block.AddTx(tx2)
case 2:
// Block 3 is empty but was mined by account #2.
block.SetCoinbase(acc2Addr)
block.SetExtra([]byte("yeehaw"))
case 3:
// Block 4 includes blocks 2 and 3 as uncle headers (with modified extra data).
b2 := block.PrevBlock(1).Header()
b2.Extra = []byte("foo")
block.AddUncle(b2)
b3 := block.PrevBlock(2).Header()
b3.Extra = []byte("foo")
block.AddUncle(b3)
}
}
// Assemble the test environment
pm := newTestProtocolManagerMust(t, false, 4, generator, nil)
peer, _ := newTestPeer("peer", protocol, pm, true)
defer peer.close()
// Fetch for now the entire chain db
hashes := []common.Hash{}
for _, key := range pm.chaindb.(*ethdb.MemDatabase).Keys() {
if len(key) == len(common.Hash{}) {
hashes = append(hashes, common.BytesToHash(key))
}
}
p2p.Send(peer.app, 0x0d, hashes)
msg, err := peer.app.ReadMsg()
if err != nil {
t.Fatalf("failed to read node data response: %v", err)
}
if msg.Code != 0x0e {
t.Fatalf("response packet code mismatch: have %x, want %x", msg.Code, 0x0c)
}
var data [][]byte
if err := msg.Decode(&data); err != nil {
t.Fatalf("failed to decode response node data: %v", err)
}
// Verify that all hashes correspond to the requested data, and reconstruct a state tree
for i, want := range hashes {
if hash := crypto.Keccak256Hash(data[i]); hash != want {
t.Errorf("data hash mismatch: have %x, want %x", hash, want)
}
}
statedb, _ := ethdb.NewMemDatabase()
for i := 0; i < len(data); i++ {
statedb.Put(hashes[i].Bytes(), data[i])
}
accounts := []common.Address{testBank.Address, acc1Addr, acc2Addr}
for i := uint64(0); i <= pm.blockchain.CurrentBlock().NumberU64(); i++ {
trie, _ := state.New(pm.blockchain.GetBlockByNumber(i).Root(), statedb)
for j, acc := range accounts {
state, _ := pm.blockchain.State()
bw := state.GetBalance(acc)
bh := trie.GetBalance(acc)
if (bw != nil && bh == nil) || (bw == nil && bh != nil) {
t.Errorf("test %d, account %d: balance mismatch: have %v, want %v", i, j, bh, bw)
}
if bw != nil && bh != nil && bw.Cmp(bw) != 0 {
t.Errorf("test %d, account %d: balance mismatch: have %v, want %v", i, j, bh, bw)
}
}
}
}
func (tab *Table) lookup(targetID NodeID, refreshIfEmpty bool) []*Node {
var (
target = crypto.Keccak256Hash(targetID[:])
asked = make(map[NodeID]bool)
seen = make(map[NodeID]bool)
reply = make(chan []*Node, alpha)
pendingQueries = 0
result *nodesByDistance
)
// don't query further if we hit ourself.
// unlikely to happen often in practice.
asked[tab.self.ID] = true
for {
tab.mutex.Lock()
// generate initial result set
result = tab.closest(target, bucketSize)
tab.mutex.Unlock()
if len(result.entries) > 0 || !refreshIfEmpty {
break
}
// The result set is empty, all nodes were dropped, refresh.
// We actually wait for the refresh to complete here. The very
// first query will hit this case and run the bootstrapping
// logic.
<-tab.refresh()
refreshIfEmpty = false
}
for {
// ask the alpha closest nodes that we haven't asked yet
for i := 0; i < len(result.entries) && pendingQueries < alpha; i++ {
n := result.entries[i]
if !asked[n.ID] {
asked[n.ID] = true
pendingQueries++
go func() {
// Find potential neighbors to bond with
r, err := tab.net.findnode(n.ID, n.addr(), targetID)
if err != nil {
// Bump the failure counter to detect and evacuate non-bonded entries
fails := tab.db.findFails(n.ID) + 1
tab.db.updateFindFails(n.ID, fails)
glog.V(logger.Detail).Infof("Bumping failures for %x: %d", n.ID[:8], fails)
if fails >= maxFindnodeFailures {
glog.V(logger.Detail).Infof("Evacuating node %x: %d findnode failures", n.ID[:8], fails)
tab.delete(n)
}
}
reply <- tab.bondall(r)
}()
}
}
if pendingQueries == 0 {
// we have asked all closest nodes, stop the search
break
}
// wait for the next reply
for _, n := range <-reply {
if n != nil && !seen[n.ID] {
seen[n.ID] = true
result.push(n, bucketSize)
}
}
pendingQueries--
}
return result.entries
}