statedb

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Published: Aug 19, 2020 License: GPL-3.0 Imports: 26 Imported by: 24

Documentation

Overview

Package statedb implements the Merkle Patricia Trie structure used for state object trie. This package is used to read/write data from/to the state object trie.

Overview of statedb package

There are 3 key struct in this package: Trie, SecureTrie and Database.

Trie struct represents a Merkle Patricia Trie.

SecureTrie is a basically same as Trie but it wraps a trie with key hashing. In a SecureTrie, all access operations hash the key using keccak256. This prevents calling code from creating long chains of nodes that increase the access time.

Database is an intermediate write layer between the trie data structures and the disk database. The aim is to accumulate trie writes in-memory and only periodically flush a couple tries to disk, garbage collecting the remainder.

Source Files

Related functions and variables are defined in the files listed below

  • database.go : Implementation of Database struct
  • derive_sha.go : Implementation of DeriveShaOrig used in Klaytn
  • encoding.go : Implementation of 3 encodings: KEYBYTES, HEX and COMPACT
  • errors.go : Errors used in this package
  • hasher.go : Implementation of recursive and bottom-up hashing
  • iterator.go : Implementation of key-value trie iterator that traverses a Trie
  • node.go : Implementation of 4 types of nodes, used in Merkle Patricia Trie
  • proof.go : Functions which construct a Merkle Patricia Proof for the given key
  • secure_trie.go : Implementation of Merkle Patricia Trie with key hashing
  • sync.go : Implementation of state trie sync
  • trie.go : Implementation of Merkle Patricia Trie

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/>.

This file is derived from trie/sync_test.go (2020/05/20). Modified and improved for the klaytn development.

Index

Constants

View Source
const AutoScaling = -1

AutoScaling is for auto-scaling cache size. If cacheSize is set to this value, cache size is set scaling to physical memeory

Variables

View Source
var ErrAlreadyProcessed = errors.New("already processed")

ErrAlreadyProcessed is returned by the trie sync when it's requested to process a node it already processed previously.

View Source
var ErrNotRequested = errors.New("not requested")

ErrNotRequested is returned by the trie sync when it's requested to process a node it did not request.

View Source
var (
	ErrZeroHashNode = errors.New("cannot retrieve a node which has 0x00 hash value")
)

Functions

func GetHashAndHexKey

func GetHashAndHexKey(key []byte) ([]byte, []byte)

func HexPathToString added in v1.5.0

func HexPathToString(path []byte) string

HexPathToString turns hex nibbles of trie path key into string of the trie path key.

func VerifyProof

func VerifyProof(rootHash common.Hash, key []byte, proofDB database.DBManager) (value []byte, err error, nodes int)

VerifyProof checks merkle proofs. The given proof must contain the value for key in a trie with the given root hash. VerifyProof returns an error if the proof contains invalid trie nodes or the wrong value.

Types

type Database

type Database struct {
	// contains filtered or unexported fields
}

Database is an intermediate write layer between the trie data structures and the disk database. The aim is to accumulate trie writes in-memory and only periodically flush a couple tries to disk, garbage collecting the remainder.

func NewDatabase

func NewDatabase(diskDB database.DBManager) *Database

NewDatabase creates a new trie database to store ephemeral trie content before its written out to disk or garbage collected.

func NewDatabaseWithExistingCache added in v1.5.0

func NewDatabaseWithExistingCache(diskDB database.DBManager, cache *fastcache.Cache) *Database

NewDatabaseWithExistingCache creates a new trie database to store ephemeral trie content before its written out to disk or garbage collected. It also acts as a read cache for nodes loaded from disk.

func NewDatabaseWithNewCache added in v1.5.0

func NewDatabaseWithNewCache(diskDB database.DBManager, cacheSizeMB int) *Database

NewDatabaseWithNewCache creates a new trie database to store ephemeral trie content before its written out to disk or garbage collected. It also acts as a read cache for nodes loaded from disk.

func (*Database) Cap

func (db *Database) Cap(limit common.StorageSize) error

Cap iteratively flushes old but still referenced trie nodes until the total memory usage goes below the given threshold.

func (*Database) Commit

func (db *Database) Commit(node common.Hash, report bool, blockNum uint64) error

Commit iterates over all the children of a particular node, writes them out to disk, forcefully tearing down all references in both directions.

As a side effect, all pre-images accumulated up to this point are also written.

func (*Database) Dereference

func (db *Database) Dereference(root common.Hash)

Dereference removes an existing reference from a root node.

func (*Database) DiskDB

func (db *Database) DiskDB() database.DBManager

DiskDB retrieves the persistent database backing the trie database.

func (*Database) DoesExistCachedNode added in v1.4.0

func (db *Database) DoesExistCachedNode(hash common.Hash) bool

DoesExistCachedNode returns if the node exists on cached trie node in memory.

func (*Database) DoesExistNodeInPersistent added in v1.5.0

func (db *Database) DoesExistNodeInPersistent(hash common.Hash) bool

DoesExistNodeInPersistent returns if the node exists on the persistent database or its cache.

func (*Database) GetTrieNodeCacheLimit added in v1.5.0

func (db *Database) GetTrieNodeCacheLimit() int

GetTrieNodeCacheLimit returns the byte size of trie node cache.

func (*Database) InsertBlob

func (db *Database) InsertBlob(hash common.Hash, blob []byte)

InsertBlob writes a new reference tracked blob to the memory database if it's yet unknown. This method should only be used for non-trie nodes that require reference counting, since trie nodes are garbage collected directly through their embedded children.

func (*Database) Node

func (db *Database) Node(hash common.Hash) ([]byte, error)

Node retrieves an encoded cached trie node from memory. If it cannot be found cached, the method queries the persistent database for the content.

func (*Database) NodeChildren added in v1.5.0

func (db *Database) NodeChildren(hash common.Hash) ([]common.Hash, error)

NodeChildren retrieves the children of the given hash trie

func (*Database) NodeFromOld added in v1.5.0

func (db *Database) NodeFromOld(hash common.Hash) ([]byte, error)

NodeFromOld retrieves an encoded cached trie node from memory. If it cannot be found cached, the method queries the old persistent database for the content.

func (*Database) Nodes

func (db *Database) Nodes() []common.Hash

Nodes retrieves the hashes of all the nodes cached within the memory database. This method is extremely expensive and should only be used to validate internal states in test code.

func (*Database) RLockGCCachedNode added in v1.4.0

func (db *Database) RLockGCCachedNode()

RLockGCCachedNode locks the GC lock of CachedNode.

func (*Database) RUnlockGCCachedNode added in v1.4.0

func (db *Database) RUnlockGCCachedNode()

RUnlockGCCachedNode unlocks the GC lock of CachedNode.

func (*Database) Reference

func (db *Database) Reference(child common.Hash, parent common.Hash)

Reference adds a new reference from a parent node to a child node.

func (*Database) Size

Size returns the current database size of the memory cache in front of the persistent database layer.

func (*Database) TrieNodeCache added in v1.5.0

func (db *Database) TrieNodeCache() *fastcache.Cache

TrieNodeCache retrieves the trieNodeCache of the trie database.

func (*Database) UpdateMetricNodes

func (db *Database) UpdateMetricNodes()

UpdateMetricNodes updates the size of Database.nodes

type DatabaseReader

type DatabaseReader interface {
	// Get retrieves the value associated with key from the database.
	Get(key []byte) (value []byte, err error)

	// Has retrieves whether a key is present in the database.
	Has(key []byte) (bool, error)
}

type DeriveShaOrig

type DeriveShaOrig struct{}

func (DeriveShaOrig) DeriveSha

func (d DeriveShaOrig) DeriveSha(list types.DerivableList) common.Hash

type Iterator

type Iterator struct {
	Key   []byte // Current data key on which the iterator is positioned on
	Value []byte // Current data value on which the iterator is positioned on
	Err   error
	// contains filtered or unexported fields
}

Iterator is a key-value trie iterator that traverses a Trie.

func NewIterator

func NewIterator(it NodeIterator) *Iterator

NewIterator creates a new key-value iterator from a node iterator

func (*Iterator) Next

func (it *Iterator) Next() bool

Next moves the iterator forward one key-value entry.

type LeafCallback

type LeafCallback func(leaf []byte, parent common.Hash, parentDepth int) error

LeafCallback is a callback type invoked when a trie operation reaches a leaf node. It's used by state sync and commit to allow handling external references between account and database tries.

type MissingNodeError

type MissingNodeError struct {
	NodeHash common.Hash // hash of the missing node
	Path     []byte      // hex-encoded path to the missing node
}

MissingNodeError is returned by the trie functions (TryGet, TryUpdate, TryDelete) in the case where a trie node is not present in the local database. It contains information necessary for retrieving the missing node.

func (*MissingNodeError) Error

func (err *MissingNodeError) Error() string

type NodeIterator

type NodeIterator interface {
	// Next moves the iterator to the next node. If the parameter is false, any child
	// nodes will be skipped.
	Next(bool) bool
	// Error returns the error status of the iterator.
	Error() error

	// Hash returns the hash of the current node.
	Hash() common.Hash
	// Parent returns the hash of the parent of the current node. The hash may be the one
	// grandparent if the immediate parent is an internal node with no hash.
	Parent() common.Hash
	// Path returns the hex-encoded path to the current node.
	// Callers must not retain references to the return value after calling Next.
	// For leaf nodes, the last element of the path is the 'terminator symbol' 0x10.
	Path() []byte

	// Leaf returns true iff the current node is a leaf node.
	// LeafBlob, LeafKey return the contents and key of the leaf node. These
	// method panic if the iterator is not positioned at a leaf.
	// Callers must not retain references to their return value after calling Next
	Leaf() bool

	// LeafKey returns the key of the leaf. The method panics if the iterator is not
	// positioned at a leaf. Callers must not retain references to the value after
	// calling Next.
	LeafKey() []byte

	// LeafBlob returns the content of the leaf. The method panics if the iterator
	// is not positioned at a leaf. Callers must not retain references to the value
	// after calling Next.
	LeafBlob() []byte

	// LeafProof returns the Merkle proof of the leaf. The method panics if the
	// iterator is not positioned at a leaf. Callers must not retain references
	// to the value after calling Next.
	LeafProof() [][]byte
}

NodeIterator is an iterator to traverse the trie pre-order.

func NewDifferenceIterator

func NewDifferenceIterator(a, b NodeIterator) (NodeIterator, *int)

NewDifferenceIterator constructs a NodeIterator that iterates over elements in b that are not in a. Returns the iterator, and a pointer to an integer recording the number of nodes seen.

func NewUnionIterator

func NewUnionIterator(iters []NodeIterator) (NodeIterator, *int)

NewUnionIterator constructs a NodeIterator that iterates over elements in the union of the provided NodeIterators. Returns the iterator, and a pointer to an integer recording the number of nodes visited.

type SecureTrie

type SecureTrie struct {
	// contains filtered or unexported fields
}

SecureTrie wraps a trie with key hashing. In a secure trie, all access operations hash the key using keccak256. This prevents calling code from creating long chains of nodes that increase the access time.

Contrary to a regular trie, a SecureTrie can only be created with NewTrie and must have an attached database. The database also stores the preimage of each key.

SecureTrie is not safe for concurrent use.

func NewSecureTrie

func NewSecureTrie(root common.Hash, db *Database) (*SecureTrie, error)

NewSecureTrie creates a trie with an existing root node from a backing database and optional intermediate in-memory node pool.

If root is the zero hash or the sha3 hash of an empty string, the trie is initially empty. Otherwise, NewTrie will panic if db is nil and returns MissingNodeError if the root node cannot be found.

Accessing the trie loads nodes from the database or node pool on demand. Loaded nodes are kept around until their 'cache generation' expires. A new cache generation is created by each call to Commit. cachelimit sets the number of past cache generations to keep.

func (*SecureTrie) Commit

func (t *SecureTrie) Commit(onleaf LeafCallback) (root common.Hash, err error)

Commit writes all nodes and the secure hash pre-images to the trie's database. Nodes are stored with their sha3 hash as the key.

Committing flushes nodes from memory. Subsequent Get calls will load nodes from the database.

func (*SecureTrie) Copy

func (t *SecureTrie) Copy() *SecureTrie

func (*SecureTrie) Delete

func (t *SecureTrie) Delete(key []byte)

Delete removes any existing value for key from the trie.

func (*SecureTrie) Get

func (t *SecureTrie) Get(key []byte) []byte

Get returns the value for key stored in the trie. The value bytes must not be modified by the caller.

func (*SecureTrie) GetKey

func (t *SecureTrie) GetKey(shaKey []byte) []byte

GetKey returns the sha3 preimage of a hashed key that was previously used to store a value.

func (*SecureTrie) Hash

func (t *SecureTrie) Hash() common.Hash

func (*SecureTrie) NodeIterator

func (t *SecureTrie) NodeIterator(start []byte) NodeIterator

NodeIterator returns an iterator that returns nodes of the underlying trie. Iteration starts at the key after the given start key.

func (*SecureTrie) Prove

func (t *SecureTrie) Prove(key []byte, fromLevel uint, proofDB database.DBManager) error

NOTE-Klaytn-RemoveLater Below Prove is only used in tests, not in core codes. Prove constructs a merkle proof for key. The result contains all encoded nodes on the path to the value at key. The value itself is also included in the last node and can be retrieved by verifying the proof.

If the trie does not contain a value for key, the returned proof contains all nodes of the longest existing prefix of the key (at least the root node), ending with the node that proves the absence of the key.

func (*SecureTrie) TryDelete

func (t *SecureTrie) TryDelete(key []byte) error

TryDelete removes any existing value for key from the trie. If a node was not found in the database, a MissingNodeError is returned.

func (*SecureTrie) TryGet

func (t *SecureTrie) TryGet(key []byte) ([]byte, error)

TryGet returns the value for key stored in the trie. The value bytes must not be modified by the caller. If a node was not found in the database, a MissingNodeError is returned.

func (*SecureTrie) TryUpdate

func (t *SecureTrie) TryUpdate(key, value []byte) error

TryUpdate associates key with value in the trie. Subsequent calls to Get will return value. If value has length zero, any existing value is deleted from the trie and calls to Get will return nil.

The value bytes must not be modified by the caller while they are stored in the trie.

If a node was not found in the database, a MissingNodeError is returned.

func (*SecureTrie) TryUpdateWithKeys

func (t *SecureTrie) TryUpdateWithKeys(key, hashKey, hexKey, value []byte) error

TryUpdateWithKeys does basically same thing that TryUpdate does. Only difference is that it uses pre-encoded hashKey and hexKey.

func (*SecureTrie) Update

func (t *SecureTrie) Update(key, value []byte)

Update associates key with value in the trie. Subsequent calls to Get will return value. If value has length zero, any existing value is deleted from the trie and calls to Get will return nil.

The value bytes must not be modified by the caller while they are stored in the trie.

type StateTrieReadDB added in v1.5.0

type StateTrieReadDB interface {
	ReadStateTrieNode(key []byte) ([]byte, error)
	HasStateTrieNode(key []byte) (bool, error)
}

type SyncBloom added in v1.5.0

type SyncBloom struct {
	// contains filtered or unexported fields
}

SyncBloom is a bloom filter used during fast sync to quickly decide if a trie node already exists on disk or not. It self populates from the provided disk database on creation in a background thread and will only start returning live results once that's finished.

func NewSyncBloom added in v1.5.0

func NewSyncBloom(memory uint64, database database.Iteratee) *SyncBloom

NewSyncBloom creates a new bloom filter of the given size (in megabytes) and initializes it from the database. The bloom is hard coded to use 3 filters.

func (*SyncBloom) Add added in v1.5.0

func (b *SyncBloom) Add(hash []byte)

Add inserts a new trie node hash into the bloom filter.

func (*SyncBloom) Close added in v1.5.0

func (b *SyncBloom) Close() error

Close terminates any background initializer still running and releases all the memory allocated for the bloom.

func (*SyncBloom) Contains added in v1.5.0

func (b *SyncBloom) Contains(hash []byte) bool

Contains tests if the bloom filter contains the given hash:

  • false: the bloom definitely does not contain hash
  • true: the bloom maybe contains hash

While the bloom is being initialized, any query will return true.

type SyncResult

type SyncResult struct {
	Hash common.Hash // Hash of the originally unknown trie node
	Data []byte      // Data content of the retrieved node
	Err  error
}

SyncResult is a simple list to return missing nodes along with their request hashes.

type Trie

type Trie struct {
	// contains filtered or unexported fields
}

Trie is a Merkle Patricia Trie. The zero value is an empty trie with no database. Use NewTrie to create a trie that sits on top of a database.

Trie is not safe for concurrent use.

func NewTrie

func NewTrie(root common.Hash, db *Database) (*Trie, error)

NewTrie creates a trie with an existing root node from db.

If root is the zero hash or the sha3 hash of an empty string, the trie is initially empty and does not require a database. Otherwise, NewTrie will panic if db is nil and returns a MissingNodeError if root does not exist in the database. Accessing the trie loads nodes from db on demand.

func (*Trie) Commit

func (t *Trie) Commit(onleaf LeafCallback) (root common.Hash, err error)

Commit writes all nodes to the trie's memory database, tracking the internal and external (for account tries) references.

func (*Trie) Delete

func (t *Trie) Delete(key []byte)

Delete removes any existing value for key from the trie.

func (*Trie) Get

func (t *Trie) Get(key []byte) []byte

Get returns the value for key stored in the trie. The value bytes must not be modified by the caller.

func (*Trie) Hash

func (t *Trie) Hash() common.Hash

Hash returns the root hash of the trie. It does not write to the database and can be used even if the trie doesn't have one.

func (*Trie) NodeIterator

func (t *Trie) NodeIterator(start []byte) NodeIterator

NodeIterator returns an iterator that returns nodes of the trie. Iteration starts at the key after the given start key.

func (*Trie) Prove

func (t *Trie) Prove(key []byte, fromLevel uint, proofDB database.DBManager) error

NOTE-Klaytn-RemoveLater Below Prove is only used in tests, not in core codes. Prove constructs a merkle proof for key. The result contains all encoded nodes on the path to the value at key. The value itself is also included in the last node and can be retrieved by verifying the proof.

If the trie does not contain a value for key, the returned proof contains all nodes of the longest existing prefix of the key (at least the root node), ending with the node that proves the absence of the key.

func (*Trie) TryDelete

func (t *Trie) TryDelete(key []byte) error

TryDelete removes any existing value for key from the trie. If a node was not found in the database, a MissingNodeError is returned.

func (*Trie) TryGet

func (t *Trie) TryGet(key []byte) ([]byte, error)

TryGet returns the value for key stored in the trie. The value bytes must not be modified by the caller. If a node was not found in the database, a MissingNodeError is returned.

func (*Trie) TryUpdate

func (t *Trie) TryUpdate(key, value []byte) error

TryUpdate associates key with value in the trie. Subsequent calls to Get will return value. If value has length zero, any existing value is deleted from the trie and calls to Get will return nil.

The value bytes must not be modified by the caller while they are stored in the trie.

If a node was not found in the database, a MissingNodeError is returned.

func (*Trie) TryUpdateWithHexKey

func (t *Trie) TryUpdateWithHexKey(hexKey, value []byte) error

TryUpdateWithHexKey uses pre-generated hexKey. It is both called from TryUpdate and SecureTrie.TryUpdateWithKeys.

func (*Trie) Update

func (t *Trie) Update(key, value []byte)

Update associates key with value in the trie. Subsequent calls to Get will return value. If value has length zero, any existing value is deleted from the trie and calls to Get will return nil.

The value bytes must not be modified by the caller while they are stored in the trie.

type TrieSync

type TrieSync struct {
	// contains filtered or unexported fields
}

TrieSync is the main state trie synchronisation scheduler, which provides yet unknown trie hashes to retrieve, accepts node data associated with said hashes and reconstructs the trie step by step until all is done.

func NewTrieSync

func NewTrieSync(root common.Hash, database StateTrieReadDB, callback LeafCallback, bloom *SyncBloom, lruCache *lru.Cache) *TrieSync

NewTrieSync creates a new trie data download scheduler. If both bloom and cache are set, only cache is used.

func (*TrieSync) AddRawEntry

func (s *TrieSync) AddRawEntry(hash common.Hash, depth int, parent common.Hash)

AddRawEntry schedules the direct retrieval of a state entry that should not be interpreted as a trie node, but rather accepted and stored into the database as is. This method's goal is to support misc state metadata retrievals (e.g. contract code).

func (*TrieSync) AddSubTrie

func (s *TrieSync) AddSubTrie(root common.Hash, depth int, parent common.Hash, callback LeafCallback)

AddSubTrie registers a new trie to the sync code, rooted at the designated parent.

func (*TrieSync) CalcProgressPercentage added in v1.5.0

func (s *TrieSync) CalcProgressPercentage() float64

CalcProgressPercentage returns the progress percentage.

func (*TrieSync) Commit

func (s *TrieSync) Commit(dbw database.Putter) (int, error)

Commit flushes the data stored in the internal membatch out to persistent storage, returning the number of items written and any occurred error.

func (*TrieSync) CommittedByDepth added in v1.5.0

func (s *TrieSync) CommittedByDepth(depth int) int

CommittedByDepth returns the committed trie count by given depth.

func (*TrieSync) Missing

func (s *TrieSync) Missing(max int) []common.Hash

Missing retrieves the known missing nodes from the trie for retrieval.

func (*TrieSync) Pending

func (s *TrieSync) Pending() int

Pending returns the number of state entries currently pending for download.

func (*TrieSync) Process

func (s *TrieSync) Process(results []SyncResult) (bool, int, error)

Process injects a batch of retrieved trie nodes data, returning if something was committed to the database and also the index of an entry if processing of it failed.

func (*TrieSync) RetrievedByDepth added in v1.5.0

func (s *TrieSync) RetrievedByDepth(depth int) int

RetrievedByDepth returns the retrieved trie count by given depth. This number is same as the number of nodes that needs to be commited to complete trie sync.

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