plugeth/trie/stacktrie.go
rjl493456442 99f81d2724
all: refactor trie API (#26995)
In this PR, all TryXXX(e.g. TryGet) APIs of trie are renamed to XXX(e.g. Get) with an error returned.

The original XXX(e.g. Get) APIs are renamed to MustXXX(e.g. MustGet) and does not return any error -- they print a log output. A future PR will change the behaviour to panic on errorrs.
2023-04-20 06:57:24 -04:00

535 lines
14 KiB
Go

// Copyright 2020 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 trie
import (
"bufio"
"bytes"
"encoding/gob"
"errors"
"io"
"sync"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/log"
)
var ErrCommitDisabled = errors.New("no database for committing")
var stPool = sync.Pool{
New: func() interface{} {
return NewStackTrie(nil)
},
}
// NodeWriteFunc is used to provide all information of a dirty node for committing
// so that callers can flush nodes into database with desired scheme.
type NodeWriteFunc = func(owner common.Hash, path []byte, hash common.Hash, blob []byte)
func stackTrieFromPool(writeFn NodeWriteFunc, owner common.Hash) *StackTrie {
st := stPool.Get().(*StackTrie)
st.owner = owner
st.writeFn = writeFn
return st
}
func returnToPool(st *StackTrie) {
st.Reset()
stPool.Put(st)
}
// StackTrie is a trie implementation that expects keys to be inserted
// in order. Once it determines that a subtree will no longer be inserted
// into, it will hash it and free up the memory it uses.
type StackTrie struct {
owner common.Hash // the owner of the trie
nodeType uint8 // node type (as in branch, ext, leaf)
val []byte // value contained by this node if it's a leaf
key []byte // key chunk covered by this (leaf|ext) node
children [16]*StackTrie // list of children (for branch and exts)
writeFn NodeWriteFunc // function for committing nodes, can be nil
}
// NewStackTrie allocates and initializes an empty trie.
func NewStackTrie(writeFn NodeWriteFunc) *StackTrie {
return &StackTrie{
nodeType: emptyNode,
writeFn: writeFn,
}
}
// NewStackTrieWithOwner allocates and initializes an empty trie, but with
// the additional owner field.
func NewStackTrieWithOwner(writeFn NodeWriteFunc, owner common.Hash) *StackTrie {
return &StackTrie{
owner: owner,
nodeType: emptyNode,
writeFn: writeFn,
}
}
// NewFromBinary initialises a serialized stacktrie with the given db.
func NewFromBinary(data []byte, writeFn NodeWriteFunc) (*StackTrie, error) {
var st StackTrie
if err := st.UnmarshalBinary(data); err != nil {
return nil, err
}
// If a database is used, we need to recursively add it to every child
if writeFn != nil {
st.setWriter(writeFn)
}
return &st, nil
}
// MarshalBinary implements encoding.BinaryMarshaler
func (st *StackTrie) MarshalBinary() (data []byte, err error) {
var (
b bytes.Buffer
w = bufio.NewWriter(&b)
)
if err := gob.NewEncoder(w).Encode(struct {
Owner common.Hash
NodeType uint8
Val []byte
Key []byte
}{
st.owner,
st.nodeType,
st.val,
st.key,
}); err != nil {
return nil, err
}
for _, child := range st.children {
if child == nil {
w.WriteByte(0)
continue
}
w.WriteByte(1)
if childData, err := child.MarshalBinary(); err != nil {
return nil, err
} else {
w.Write(childData)
}
}
w.Flush()
return b.Bytes(), nil
}
// UnmarshalBinary implements encoding.BinaryUnmarshaler
func (st *StackTrie) UnmarshalBinary(data []byte) error {
r := bytes.NewReader(data)
return st.unmarshalBinary(r)
}
func (st *StackTrie) unmarshalBinary(r io.Reader) error {
var dec struct {
Owner common.Hash
NodeType uint8
Val []byte
Key []byte
}
if err := gob.NewDecoder(r).Decode(&dec); err != nil {
return err
}
st.owner = dec.Owner
st.nodeType = dec.NodeType
st.val = dec.Val
st.key = dec.Key
var hasChild = make([]byte, 1)
for i := range st.children {
if _, err := r.Read(hasChild); err != nil {
return err
} else if hasChild[0] == 0 {
continue
}
var child StackTrie
if err := child.unmarshalBinary(r); err != nil {
return err
}
st.children[i] = &child
}
return nil
}
func (st *StackTrie) setWriter(writeFn NodeWriteFunc) {
st.writeFn = writeFn
for _, child := range st.children {
if child != nil {
child.setWriter(writeFn)
}
}
}
func newLeaf(owner common.Hash, key, val []byte, writeFn NodeWriteFunc) *StackTrie {
st := stackTrieFromPool(writeFn, owner)
st.nodeType = leafNode
st.key = append(st.key, key...)
st.val = val
return st
}
func newExt(owner common.Hash, key []byte, child *StackTrie, writeFn NodeWriteFunc) *StackTrie {
st := stackTrieFromPool(writeFn, owner)
st.nodeType = extNode
st.key = append(st.key, key...)
st.children[0] = child
return st
}
// List all values that StackTrie#nodeType can hold
const (
emptyNode = iota
branchNode
extNode
leafNode
hashedNode
)
// Update inserts a (key, value) pair into the stack trie.
func (st *StackTrie) Update(key, value []byte) error {
k := keybytesToHex(key)
if len(value) == 0 {
panic("deletion not supported")
}
st.insert(k[:len(k)-1], value, nil)
return nil
}
// MustUpdate is a wrapper of Update and will omit any encountered error but
// just print out an error message.
func (st *StackTrie) MustUpdate(key, value []byte) {
if err := st.Update(key, value); err != nil {
log.Error("Unhandled trie error in StackTrie.Update", "err", err)
}
}
func (st *StackTrie) Reset() {
st.owner = common.Hash{}
st.writeFn = nil
st.key = st.key[:0]
st.val = nil
for i := range st.children {
st.children[i] = nil
}
st.nodeType = emptyNode
}
// Helper function that, given a full key, determines the index
// at which the chunk pointed by st.keyOffset is different from
// the same chunk in the full key.
func (st *StackTrie) getDiffIndex(key []byte) int {
for idx, nibble := range st.key {
if nibble != key[idx] {
return idx
}
}
return len(st.key)
}
// Helper function to that inserts a (key, value) pair into
// the trie.
func (st *StackTrie) insert(key, value []byte, prefix []byte) {
switch st.nodeType {
case branchNode: /* Branch */
idx := int(key[0])
// Unresolve elder siblings
for i := idx - 1; i >= 0; i-- {
if st.children[i] != nil {
if st.children[i].nodeType != hashedNode {
st.children[i].hash(append(prefix, byte(i)))
}
break
}
}
// Add new child
if st.children[idx] == nil {
st.children[idx] = newLeaf(st.owner, key[1:], value, st.writeFn)
} else {
st.children[idx].insert(key[1:], value, append(prefix, key[0]))
}
case extNode: /* Ext */
// Compare both key chunks and see where they differ
diffidx := st.getDiffIndex(key)
// Check if chunks are identical. If so, recurse into
// the child node. Otherwise, the key has to be split
// into 1) an optional common prefix, 2) the fullnode
// representing the two differing path, and 3) a leaf
// for each of the differentiated subtrees.
if diffidx == len(st.key) {
// Ext key and key segment are identical, recurse into
// the child node.
st.children[0].insert(key[diffidx:], value, append(prefix, key[:diffidx]...))
return
}
// Save the original part. Depending if the break is
// at the extension's last byte or not, create an
// intermediate extension or use the extension's child
// node directly.
var n *StackTrie
if diffidx < len(st.key)-1 {
// Break on the non-last byte, insert an intermediate
// extension. The path prefix of the newly-inserted
// extension should also contain the different byte.
n = newExt(st.owner, st.key[diffidx+1:], st.children[0], st.writeFn)
n.hash(append(prefix, st.key[:diffidx+1]...))
} else {
// Break on the last byte, no need to insert
// an extension node: reuse the current node.
// The path prefix of the original part should
// still be same.
n = st.children[0]
n.hash(append(prefix, st.key...))
}
var p *StackTrie
if diffidx == 0 {
// the break is on the first byte, so
// the current node is converted into
// a branch node.
st.children[0] = nil
p = st
st.nodeType = branchNode
} else {
// the common prefix is at least one byte
// long, insert a new intermediate branch
// node.
st.children[0] = stackTrieFromPool(st.writeFn, st.owner)
st.children[0].nodeType = branchNode
p = st.children[0]
}
// Create a leaf for the inserted part
o := newLeaf(st.owner, key[diffidx+1:], value, st.writeFn)
// Insert both child leaves where they belong:
origIdx := st.key[diffidx]
newIdx := key[diffidx]
p.children[origIdx] = n
p.children[newIdx] = o
st.key = st.key[:diffidx]
case leafNode: /* Leaf */
// Compare both key chunks and see where they differ
diffidx := st.getDiffIndex(key)
// Overwriting a key isn't supported, which means that
// the current leaf is expected to be split into 1) an
// optional extension for the common prefix of these 2
// keys, 2) a fullnode selecting the path on which the
// keys differ, and 3) one leaf for the differentiated
// component of each key.
if diffidx >= len(st.key) {
panic("Trying to insert into existing key")
}
// Check if the split occurs at the first nibble of the
// chunk. In that case, no prefix extnode is necessary.
// Otherwise, create that
var p *StackTrie
if diffidx == 0 {
// Convert current leaf into a branch
st.nodeType = branchNode
p = st
st.children[0] = nil
} else {
// Convert current node into an ext,
// and insert a child branch node.
st.nodeType = extNode
st.children[0] = NewStackTrieWithOwner(st.writeFn, st.owner)
st.children[0].nodeType = branchNode
p = st.children[0]
}
// Create the two child leaves: one containing the original
// value and another containing the new value. The child leaf
// is hashed directly in order to free up some memory.
origIdx := st.key[diffidx]
p.children[origIdx] = newLeaf(st.owner, st.key[diffidx+1:], st.val, st.writeFn)
p.children[origIdx].hash(append(prefix, st.key[:diffidx+1]...))
newIdx := key[diffidx]
p.children[newIdx] = newLeaf(st.owner, key[diffidx+1:], value, st.writeFn)
// Finally, cut off the key part that has been passed
// over to the children.
st.key = st.key[:diffidx]
st.val = nil
case emptyNode: /* Empty */
st.nodeType = leafNode
st.key = key
st.val = value
case hashedNode:
panic("trying to insert into hash")
default:
panic("invalid type")
}
}
// hash converts st into a 'hashedNode', if possible. Possible outcomes:
//
// 1. The rlp-encoded value was >= 32 bytes:
// - Then the 32-byte `hash` will be accessible in `st.val`.
// - And the 'st.type' will be 'hashedNode'
//
// 2. The rlp-encoded value was < 32 bytes
// - Then the <32 byte rlp-encoded value will be accessible in 'st.val'.
// - And the 'st.type' will be 'hashedNode' AGAIN
//
// This method also sets 'st.type' to hashedNode, and clears 'st.key'.
func (st *StackTrie) hash(path []byte) {
h := newHasher(false)
defer returnHasherToPool(h)
st.hashRec(h, path)
}
func (st *StackTrie) hashRec(hasher *hasher, path []byte) {
// The switch below sets this to the RLP-encoding of this node.
var encodedNode []byte
switch st.nodeType {
case hashedNode:
return
case emptyNode:
st.val = types.EmptyRootHash.Bytes()
st.key = st.key[:0]
st.nodeType = hashedNode
return
case branchNode:
var nodes rawFullNode
for i, child := range st.children {
if child == nil {
nodes[i] = nilValueNode
continue
}
child.hashRec(hasher, append(path, byte(i)))
if len(child.val) < 32 {
nodes[i] = rawNode(child.val)
} else {
nodes[i] = hashNode(child.val)
}
// Release child back to pool.
st.children[i] = nil
returnToPool(child)
}
nodes.encode(hasher.encbuf)
encodedNode = hasher.encodedBytes()
case extNode:
st.children[0].hashRec(hasher, append(path, st.key...))
n := rawShortNode{Key: hexToCompact(st.key)}
if len(st.children[0].val) < 32 {
n.Val = rawNode(st.children[0].val)
} else {
n.Val = hashNode(st.children[0].val)
}
n.encode(hasher.encbuf)
encodedNode = hasher.encodedBytes()
// Release child back to pool.
returnToPool(st.children[0])
st.children[0] = nil
case leafNode:
st.key = append(st.key, byte(16))
n := rawShortNode{Key: hexToCompact(st.key), Val: valueNode(st.val)}
n.encode(hasher.encbuf)
encodedNode = hasher.encodedBytes()
default:
panic("invalid node type")
}
st.nodeType = hashedNode
st.key = st.key[:0]
if len(encodedNode) < 32 {
st.val = common.CopyBytes(encodedNode)
return
}
// Write the hash to the 'val'. We allocate a new val here to not mutate
// input values
st.val = hasher.hashData(encodedNode)
if st.writeFn != nil {
st.writeFn(st.owner, path, common.BytesToHash(st.val), encodedNode)
}
}
// Hash returns the hash of the current node.
func (st *StackTrie) Hash() (h common.Hash) {
hasher := newHasher(false)
defer returnHasherToPool(hasher)
st.hashRec(hasher, nil)
if len(st.val) == 32 {
copy(h[:], st.val)
return h
}
// If the node's RLP isn't 32 bytes long, the node will not
// be hashed, and instead contain the rlp-encoding of the
// node. For the top level node, we need to force the hashing.
hasher.sha.Reset()
hasher.sha.Write(st.val)
hasher.sha.Read(h[:])
return h
}
// Commit will firstly hash the entire trie if it's still not hashed
// and then commit all nodes to the associated database. Actually most
// of the trie nodes MAY have been committed already. The main purpose
// here is to commit the root node.
//
// The associated database is expected, otherwise the whole commit
// functionality should be disabled.
func (st *StackTrie) Commit() (h common.Hash, err error) {
if st.writeFn == nil {
return common.Hash{}, ErrCommitDisabled
}
hasher := newHasher(false)
defer returnHasherToPool(hasher)
st.hashRec(hasher, nil)
if len(st.val) == 32 {
copy(h[:], st.val)
return h, nil
}
// If the node's RLP isn't 32 bytes long, the node will not
// be hashed (and committed), and instead contain the rlp-encoding of the
// node. For the top level node, we need to force the hashing+commit.
hasher.sha.Reset()
hasher.sha.Write(st.val)
hasher.sha.Read(h[:])
st.writeFn(st.owner, nil, h, st.val)
return h, nil
}