plugeth/core/state/snapshot/generate.go
rjl493456442 6d2aeb43d5
cmd, core/state, eth, tests, trie: improve state reader (#27428)
The state availability is checked during the creation of a state reader.

-    In hash-based database, if the specified root node does not exist on disk disk, then
    the state reader won't be created and an error will be returned.

-    In path-based database, if the specified state layer is not available, then the
    state reader won't be created and an error will be returned.

This change also contains a stricter semantics regarding the `Commit` operation: once it has been performed, the trie is no longer usable, and certain operations will return an error.
2023-06-20 15:31:45 -04:00

745 lines
26 KiB
Go

// Copyright 2019 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 snapshot
import (
"bytes"
"errors"
"fmt"
"time"
"github.com/VictoriaMetrics/fastcache"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/core/rawdb"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/trie"
"github.com/ethereum/go-ethereum/trie/trienode"
)
var (
// accountCheckRange is the upper limit of the number of accounts involved in
// each range check. This is a value estimated based on experience. If this
// range is too large, the failure rate of range proof will increase. Otherwise,
// if the range is too small, the efficiency of the state recovery will decrease.
accountCheckRange = 128
// storageCheckRange is the upper limit of the number of storage slots involved
// in each range check. This is a value estimated based on experience. If this
// range is too large, the failure rate of range proof will increase. Otherwise,
// if the range is too small, the efficiency of the state recovery will decrease.
storageCheckRange = 1024
// errMissingTrie is returned if the target trie is missing while the generation
// is running. In this case the generation is aborted and wait the new signal.
errMissingTrie = errors.New("missing trie")
)
// generateSnapshot regenerates a brand new snapshot based on an existing state
// database and head block asynchronously. The snapshot is returned immediately
// and generation is continued in the background until done.
func generateSnapshot(diskdb ethdb.KeyValueStore, triedb *trie.Database, cache int, root common.Hash) *diskLayer {
// Create a new disk layer with an initialized state marker at zero
var (
stats = &generatorStats{start: time.Now()}
batch = diskdb.NewBatch()
genMarker = []byte{} // Initialized but empty!
)
rawdb.WriteSnapshotRoot(batch, root)
journalProgress(batch, genMarker, stats)
if err := batch.Write(); err != nil {
log.Crit("Failed to write initialized state marker", "err", err)
}
base := &diskLayer{
diskdb: diskdb,
triedb: triedb,
root: root,
cache: fastcache.New(cache * 1024 * 1024),
genMarker: genMarker,
genPending: make(chan struct{}),
genAbort: make(chan chan *generatorStats),
}
go base.generate(stats)
log.Debug("Start snapshot generation", "root", root)
return base
}
// journalProgress persists the generator stats into the database to resume later.
func journalProgress(db ethdb.KeyValueWriter, marker []byte, stats *generatorStats) {
// Write out the generator marker. Note it's a standalone disk layer generator
// which is not mixed with journal. It's ok if the generator is persisted while
// journal is not.
entry := journalGenerator{
Done: marker == nil,
Marker: marker,
}
if stats != nil {
entry.Accounts = stats.accounts
entry.Slots = stats.slots
entry.Storage = uint64(stats.storage)
}
blob, err := rlp.EncodeToBytes(entry)
if err != nil {
panic(err) // Cannot happen, here to catch dev errors
}
var logstr string
switch {
case marker == nil:
logstr = "done"
case bytes.Equal(marker, []byte{}):
logstr = "empty"
case len(marker) == common.HashLength:
logstr = fmt.Sprintf("%#x", marker)
default:
logstr = fmt.Sprintf("%#x:%#x", marker[:common.HashLength], marker[common.HashLength:])
}
log.Debug("Journalled generator progress", "progress", logstr)
rawdb.WriteSnapshotGenerator(db, blob)
}
// proofResult contains the output of range proving which can be used
// for further processing regardless if it is successful or not.
type proofResult struct {
keys [][]byte // The key set of all elements being iterated, even proving is failed
vals [][]byte // The val set of all elements being iterated, even proving is failed
diskMore bool // Set when the database has extra snapshot states since last iteration
trieMore bool // Set when the trie has extra snapshot states(only meaningful for successful proving)
proofErr error // Indicator whether the given state range is valid or not
tr *trie.Trie // The trie, in case the trie was resolved by the prover (may be nil)
}
// valid returns the indicator that range proof is successful or not.
func (result *proofResult) valid() bool {
return result.proofErr == nil
}
// last returns the last verified element key regardless of whether the range proof is
// successful or not. Nil is returned if nothing involved in the proving.
func (result *proofResult) last() []byte {
var last []byte
if len(result.keys) > 0 {
last = result.keys[len(result.keys)-1]
}
return last
}
// forEach iterates all the visited elements and applies the given callback on them.
// The iteration is aborted if the callback returns non-nil error.
func (result *proofResult) forEach(callback func(key []byte, val []byte) error) error {
for i := 0; i < len(result.keys); i++ {
key, val := result.keys[i], result.vals[i]
if err := callback(key, val); err != nil {
return err
}
}
return nil
}
// proveRange proves the snapshot segment with particular prefix is "valid".
// The iteration start point will be assigned if the iterator is restored from
// the last interruption. Max will be assigned in order to limit the maximum
// amount of data involved in each iteration.
//
// The proof result will be returned if the range proving is finished, otherwise
// the error will be returned to abort the entire procedure.
func (dl *diskLayer) proveRange(ctx *generatorContext, trieId *trie.ID, prefix []byte, kind string, origin []byte, max int, valueConvertFn func([]byte) ([]byte, error)) (*proofResult, error) {
var (
keys [][]byte
vals [][]byte
proof = rawdb.NewMemoryDatabase()
diskMore = false
iter = ctx.iterator(kind)
start = time.Now()
min = append(prefix, origin...)
)
for iter.Next() {
// Ensure the iterated item is always equal or larger than the given origin.
key := iter.Key()
if bytes.Compare(key, min) < 0 {
return nil, errors.New("invalid iteration position")
}
// Ensure the iterated item still fall in the specified prefix. If
// not which means the items in the specified area are all visited.
// Move the iterator a step back since we iterate one extra element
// out.
if !bytes.Equal(key[:len(prefix)], prefix) {
iter.Hold()
break
}
// Break if we've reached the max size, and signal that we're not
// done yet. Move the iterator a step back since we iterate one
// extra element out.
if len(keys) == max {
iter.Hold()
diskMore = true
break
}
keys = append(keys, common.CopyBytes(key[len(prefix):]))
if valueConvertFn == nil {
vals = append(vals, common.CopyBytes(iter.Value()))
} else {
val, err := valueConvertFn(iter.Value())
if err != nil {
// Special case, the state data is corrupted (invalid slim-format account),
// don't abort the entire procedure directly. Instead, let the fallback
// generation to heal the invalid data.
//
// Here append the original value to ensure that the number of key and
// value are aligned.
vals = append(vals, common.CopyBytes(iter.Value()))
log.Error("Failed to convert account state data", "err", err)
} else {
vals = append(vals, val)
}
}
}
// Update metrics for database iteration and merkle proving
if kind == snapStorage {
snapStorageSnapReadCounter.Inc(time.Since(start).Nanoseconds())
} else {
snapAccountSnapReadCounter.Inc(time.Since(start).Nanoseconds())
}
defer func(start time.Time) {
if kind == snapStorage {
snapStorageProveCounter.Inc(time.Since(start).Nanoseconds())
} else {
snapAccountProveCounter.Inc(time.Since(start).Nanoseconds())
}
}(time.Now())
// The snap state is exhausted, pass the entire key/val set for verification
root := trieId.Root
if origin == nil && !diskMore {
stackTr := trie.NewStackTrie(nil)
for i, key := range keys {
stackTr.Update(key, vals[i])
}
if gotRoot := stackTr.Hash(); gotRoot != root {
return &proofResult{
keys: keys,
vals: vals,
proofErr: fmt.Errorf("wrong root: have %#x want %#x", gotRoot, root),
}, nil
}
return &proofResult{keys: keys, vals: vals}, nil
}
// Snap state is chunked, generate edge proofs for verification.
tr, err := trie.New(trieId, dl.triedb)
if err != nil {
ctx.stats.Log("Trie missing, state snapshotting paused", dl.root, dl.genMarker)
return nil, errMissingTrie
}
// Firstly find out the key of last iterated element.
var last []byte
if len(keys) > 0 {
last = keys[len(keys)-1]
}
// Generate the Merkle proofs for the first and last element
if origin == nil {
origin = common.Hash{}.Bytes()
}
if err := tr.Prove(origin, proof); err != nil {
log.Debug("Failed to prove range", "kind", kind, "origin", origin, "err", err)
return &proofResult{
keys: keys,
vals: vals,
diskMore: diskMore,
proofErr: err,
tr: tr,
}, nil
}
if last != nil {
if err := tr.Prove(last, proof); err != nil {
log.Debug("Failed to prove range", "kind", kind, "last", last, "err", err)
return &proofResult{
keys: keys,
vals: vals,
diskMore: diskMore,
proofErr: err,
tr: tr,
}, nil
}
}
// Verify the snapshot segment with range prover, ensure that all flat states
// in this range correspond to merkle trie.
cont, err := trie.VerifyRangeProof(root, origin, last, keys, vals, proof)
return &proofResult{
keys: keys,
vals: vals,
diskMore: diskMore,
trieMore: cont,
proofErr: err,
tr: tr},
nil
}
// onStateCallback is a function that is called by generateRange, when processing a range of
// accounts or storage slots. For each element, the callback is invoked.
//
// - If 'delete' is true, then this element (and potential slots) needs to be deleted from the snapshot.
// - If 'write' is true, then this element needs to be updated with the 'val'.
// - If 'write' is false, then this element is already correct, and needs no update.
// The 'val' is the canonical encoding of the value (not the slim format for accounts)
//
// However, for accounts, the storage trie of the account needs to be checked. Also,
// dangling storages(storage exists but the corresponding account is missing) need to
// be cleaned up.
type onStateCallback func(key []byte, val []byte, write bool, delete bool) error
// generateRange generates the state segment with particular prefix. Generation can
// either verify the correctness of existing state through range-proof and skip
// generation, or iterate trie to regenerate state on demand.
func (dl *diskLayer) generateRange(ctx *generatorContext, trieId *trie.ID, prefix []byte, kind string, origin []byte, max int, onState onStateCallback, valueConvertFn func([]byte) ([]byte, error)) (bool, []byte, error) {
// Use range prover to check the validity of the flat state in the range
result, err := dl.proveRange(ctx, trieId, prefix, kind, origin, max, valueConvertFn)
if err != nil {
return false, nil, err
}
last := result.last()
// Construct contextual logger
logCtx := []interface{}{"kind", kind, "prefix", hexutil.Encode(prefix)}
if len(origin) > 0 {
logCtx = append(logCtx, "origin", hexutil.Encode(origin))
}
logger := log.New(logCtx...)
// The range prover says the range is correct, skip trie iteration
if result.valid() {
snapSuccessfulRangeProofMeter.Mark(1)
logger.Trace("Proved state range", "last", hexutil.Encode(last))
// The verification is passed, process each state with the given
// callback function. If this state represents a contract, the
// corresponding storage check will be performed in the callback
if err := result.forEach(func(key []byte, val []byte) error { return onState(key, val, false, false) }); err != nil {
return false, nil, err
}
// Only abort the iteration when both database and trie are exhausted
return !result.diskMore && !result.trieMore, last, nil
}
logger.Trace("Detected outdated state range", "last", hexutil.Encode(last), "err", result.proofErr)
snapFailedRangeProofMeter.Mark(1)
// Special case, the entire trie is missing. In the original trie scheme,
// all the duplicated subtries will be filtered out (only one copy of data
// will be stored). While in the snapshot model, all the storage tries
// belong to different contracts will be kept even they are duplicated.
// Track it to a certain extent remove the noise data used for statistics.
if origin == nil && last == nil {
meter := snapMissallAccountMeter
if kind == snapStorage {
meter = snapMissallStorageMeter
}
meter.Mark(1)
}
// We use the snap data to build up a cache which can be used by the
// main account trie as a primary lookup when resolving hashes
var resolver trie.NodeResolver
if len(result.keys) > 0 {
mdb := rawdb.NewMemoryDatabase()
tdb := trie.NewDatabase(mdb)
snapTrie := trie.NewEmpty(tdb)
for i, key := range result.keys {
snapTrie.Update(key, result.vals[i])
}
root, nodes := snapTrie.Commit(false)
if nodes != nil {
tdb.Update(root, types.EmptyRootHash, trienode.NewWithNodeSet(nodes))
tdb.Commit(root, false)
}
resolver = func(owner common.Hash, path []byte, hash common.Hash) []byte {
return rawdb.ReadTrieNode(mdb, owner, path, hash, tdb.Scheme())
}
}
// Construct the trie for state iteration, reuse the trie
// if it's already opened with some nodes resolved.
tr := result.tr
if tr == nil {
tr, err = trie.New(trieId, dl.triedb)
if err != nil {
ctx.stats.Log("Trie missing, state snapshotting paused", dl.root, dl.genMarker)
return false, nil, errMissingTrie
}
}
var (
trieMore bool
kvkeys, kvvals = result.keys, result.vals
// counters
count = 0 // number of states delivered by iterator
created = 0 // states created from the trie
updated = 0 // states updated from the trie
deleted = 0 // states not in trie, but were in snapshot
untouched = 0 // states already correct
// timers
start = time.Now()
internal time.Duration
)
nodeIt, err := tr.NodeIterator(origin)
if err != nil {
return false, nil, err
}
nodeIt.AddResolver(resolver)
iter := trie.NewIterator(nodeIt)
for iter.Next() {
if last != nil && bytes.Compare(iter.Key, last) > 0 {
trieMore = true
break
}
count++
write := true
created++
for len(kvkeys) > 0 {
if cmp := bytes.Compare(kvkeys[0], iter.Key); cmp < 0 {
// delete the key
istart := time.Now()
if err := onState(kvkeys[0], nil, false, true); err != nil {
return false, nil, err
}
kvkeys = kvkeys[1:]
kvvals = kvvals[1:]
deleted++
internal += time.Since(istart)
continue
} else if cmp == 0 {
// the snapshot key can be overwritten
created--
if write = !bytes.Equal(kvvals[0], iter.Value); write {
updated++
} else {
untouched++
}
kvkeys = kvkeys[1:]
kvvals = kvvals[1:]
}
break
}
istart := time.Now()
if err := onState(iter.Key, iter.Value, write, false); err != nil {
return false, nil, err
}
internal += time.Since(istart)
}
if iter.Err != nil {
return false, nil, iter.Err
}
// Delete all stale snapshot states remaining
istart := time.Now()
for _, key := range kvkeys {
if err := onState(key, nil, false, true); err != nil {
return false, nil, err
}
deleted += 1
}
internal += time.Since(istart)
// Update metrics for counting trie iteration
if kind == snapStorage {
snapStorageTrieReadCounter.Inc((time.Since(start) - internal).Nanoseconds())
} else {
snapAccountTrieReadCounter.Inc((time.Since(start) - internal).Nanoseconds())
}
logger.Debug("Regenerated state range", "root", trieId.Root, "last", hexutil.Encode(last),
"count", count, "created", created, "updated", updated, "untouched", untouched, "deleted", deleted)
// If there are either more trie items, or there are more snap items
// (in the next segment), then we need to keep working
return !trieMore && !result.diskMore, last, nil
}
// checkAndFlush checks if an interruption signal is received or the
// batch size has exceeded the allowance.
func (dl *diskLayer) checkAndFlush(ctx *generatorContext, current []byte) error {
var abort chan *generatorStats
select {
case abort = <-dl.genAbort:
default:
}
if ctx.batch.ValueSize() > ethdb.IdealBatchSize || abort != nil {
if bytes.Compare(current, dl.genMarker) < 0 {
log.Error("Snapshot generator went backwards", "current", fmt.Sprintf("%x", current), "genMarker", fmt.Sprintf("%x", dl.genMarker))
}
// Flush out the batch anyway no matter it's empty or not.
// It's possible that all the states are recovered and the
// generation indeed makes progress.
journalProgress(ctx.batch, current, ctx.stats)
if err := ctx.batch.Write(); err != nil {
return err
}
ctx.batch.Reset()
dl.lock.Lock()
dl.genMarker = current
dl.lock.Unlock()
if abort != nil {
ctx.stats.Log("Aborting state snapshot generation", dl.root, current)
return newAbortErr(abort) // bubble up an error for interruption
}
// Don't hold the iterators too long, release them to let compactor works
ctx.reopenIterator(snapAccount)
ctx.reopenIterator(snapStorage)
}
if time.Since(ctx.logged) > 8*time.Second {
ctx.stats.Log("Generating state snapshot", dl.root, current)
ctx.logged = time.Now()
}
return nil
}
// generateStorages generates the missing storage slots of the specific contract.
// It's supposed to restart the generation from the given origin position.
func generateStorages(ctx *generatorContext, dl *diskLayer, stateRoot common.Hash, account common.Hash, storageRoot common.Hash, storeMarker []byte) error {
onStorage := func(key []byte, val []byte, write bool, delete bool) error {
defer func(start time.Time) {
snapStorageWriteCounter.Inc(time.Since(start).Nanoseconds())
}(time.Now())
if delete {
rawdb.DeleteStorageSnapshot(ctx.batch, account, common.BytesToHash(key))
snapWipedStorageMeter.Mark(1)
return nil
}
if write {
rawdb.WriteStorageSnapshot(ctx.batch, account, common.BytesToHash(key), val)
snapGeneratedStorageMeter.Mark(1)
} else {
snapRecoveredStorageMeter.Mark(1)
}
ctx.stats.storage += common.StorageSize(1 + 2*common.HashLength + len(val))
ctx.stats.slots++
// If we've exceeded our batch allowance or termination was requested, flush to disk
if err := dl.checkAndFlush(ctx, append(account[:], key...)); err != nil {
return err
}
return nil
}
// Loop for re-generating the missing storage slots.
var origin = common.CopyBytes(storeMarker)
for {
id := trie.StorageTrieID(stateRoot, account, storageRoot)
exhausted, last, err := dl.generateRange(ctx, id, append(rawdb.SnapshotStoragePrefix, account.Bytes()...), snapStorage, origin, storageCheckRange, onStorage, nil)
if err != nil {
return err // The procedure it aborted, either by external signal or internal error.
}
// Abort the procedure if the entire contract storage is generated
if exhausted {
break
}
if origin = increaseKey(last); origin == nil {
break // special case, the last is 0xffffffff...fff
}
}
return nil
}
// generateAccounts generates the missing snapshot accounts as well as their
// storage slots in the main trie. It's supposed to restart the generation
// from the given origin position.
func generateAccounts(ctx *generatorContext, dl *diskLayer, accMarker []byte) error {
onAccount := func(key []byte, val []byte, write bool, delete bool) error {
// Make sure to clear all dangling storages before this account
account := common.BytesToHash(key)
ctx.removeStorageBefore(account)
start := time.Now()
if delete {
rawdb.DeleteAccountSnapshot(ctx.batch, account)
snapWipedAccountMeter.Mark(1)
snapAccountWriteCounter.Inc(time.Since(start).Nanoseconds())
ctx.removeStorageAt(account)
return nil
}
// Retrieve the current account and flatten it into the internal format
var acc types.StateAccount
if err := rlp.DecodeBytes(val, &acc); err != nil {
log.Crit("Invalid account encountered during snapshot creation", "err", err)
}
// If the account is not yet in-progress, write it out
if accMarker == nil || !bytes.Equal(account[:], accMarker) {
dataLen := len(val) // Approximate size, saves us a round of RLP-encoding
if !write {
if bytes.Equal(acc.CodeHash, types.EmptyCodeHash[:]) {
dataLen -= 32
}
if acc.Root == types.EmptyRootHash {
dataLen -= 32
}
snapRecoveredAccountMeter.Mark(1)
} else {
data := types.SlimAccountRLP(acc)
dataLen = len(data)
rawdb.WriteAccountSnapshot(ctx.batch, account, data)
snapGeneratedAccountMeter.Mark(1)
}
ctx.stats.storage += common.StorageSize(1 + common.HashLength + dataLen)
ctx.stats.accounts++
}
// If the snap generation goes here after interrupted, genMarker may go backward
// when last genMarker is consisted of accountHash and storageHash
marker := account[:]
if accMarker != nil && bytes.Equal(marker, accMarker) && len(dl.genMarker) > common.HashLength {
marker = dl.genMarker[:]
}
// If we've exceeded our batch allowance or termination was requested, flush to disk
if err := dl.checkAndFlush(ctx, marker); err != nil {
return err
}
snapAccountWriteCounter.Inc(time.Since(start).Nanoseconds()) // let's count flush time as well
// If the iterated account is the contract, create a further loop to
// verify or regenerate the contract storage.
if acc.Root == types.EmptyRootHash {
ctx.removeStorageAt(account)
} else {
var storeMarker []byte
if accMarker != nil && bytes.Equal(account[:], accMarker) && len(dl.genMarker) > common.HashLength {
storeMarker = dl.genMarker[common.HashLength:]
}
if err := generateStorages(ctx, dl, dl.root, account, acc.Root, storeMarker); err != nil {
return err
}
}
// Some account processed, unmark the marker
accMarker = nil
return nil
}
// Always reset the initial account range as 1 whenever recover from the
// interruption. TODO(rjl493456442) can we remove it?
var accountRange = accountCheckRange
if len(accMarker) > 0 {
accountRange = 1
}
origin := common.CopyBytes(accMarker)
for {
id := trie.StateTrieID(dl.root)
exhausted, last, err := dl.generateRange(ctx, id, rawdb.SnapshotAccountPrefix, snapAccount, origin, accountRange, onAccount, types.FullAccountRLP)
if err != nil {
return err // The procedure it aborted, either by external signal or internal error.
}
origin = increaseKey(last)
// Last step, cleanup the storages after the last account.
// All the left storages should be treated as dangling.
if origin == nil || exhausted {
ctx.removeStorageLeft()
break
}
accountRange = accountCheckRange
}
return nil
}
// generate is a background thread that iterates over the state and storage tries,
// constructing the state snapshot. All the arguments are purely for statistics
// gathering and logging, since the method surfs the blocks as they arrive, often
// being restarted.
func (dl *diskLayer) generate(stats *generatorStats) {
var (
accMarker []byte
abort chan *generatorStats
)
if len(dl.genMarker) > 0 { // []byte{} is the start, use nil for that
accMarker = dl.genMarker[:common.HashLength]
}
stats.Log("Resuming state snapshot generation", dl.root, dl.genMarker)
// Initialize the global generator context. The snapshot iterators are
// opened at the interrupted position because the assumption is held
// that all the snapshot data are generated correctly before the marker.
// Even if the snapshot data is updated during the interruption (before
// or at the marker), the assumption is still held.
// For the account or storage slot at the interruption, they will be
// processed twice by the generator(they are already processed in the
// last run) but it's fine.
ctx := newGeneratorContext(stats, dl.diskdb, accMarker, dl.genMarker)
defer ctx.close()
if err := generateAccounts(ctx, dl, accMarker); err != nil {
// Extract the received interruption signal if exists
if aerr, ok := err.(*abortErr); ok {
abort = aerr.abort
}
// Aborted by internal error, wait the signal
if abort == nil {
abort = <-dl.genAbort
}
abort <- stats
return
}
// Snapshot fully generated, set the marker to nil.
// Note even there is nothing to commit, persist the
// generator anyway to mark the snapshot is complete.
journalProgress(ctx.batch, nil, stats)
if err := ctx.batch.Write(); err != nil {
log.Error("Failed to flush batch", "err", err)
abort = <-dl.genAbort
abort <- stats
return
}
ctx.batch.Reset()
log.Info("Generated state snapshot", "accounts", stats.accounts, "slots", stats.slots,
"storage", stats.storage, "dangling", stats.dangling, "elapsed", common.PrettyDuration(time.Since(stats.start)))
dl.lock.Lock()
dl.genMarker = nil
close(dl.genPending)
dl.lock.Unlock()
// Someone will be looking for us, wait it out
abort = <-dl.genAbort
abort <- nil
}
// increaseKey increase the input key by one bit. Return nil if the entire
// addition operation overflows.
func increaseKey(key []byte) []byte {
for i := len(key) - 1; i >= 0; i-- {
key[i]++
if key[i] != 0x0 {
return key
}
}
return nil
}
// abortErr wraps an interruption signal received to represent the
// generation is aborted by external processes.
type abortErr struct {
abort chan *generatorStats
}
func newAbortErr(abort chan *generatorStats) error {
return &abortErr{abort: abort}
}
func (err *abortErr) Error() string {
return "aborted"
}