plugeth/trie/utils.go

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// Copyright 2022 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
// tracer tracks the changes of trie nodes. During the trie operations,
// some nodes can be deleted from the trie, while these deleted nodes
// won't be captured by trie.Hasher or trie.Committer. Thus, these deleted
// nodes won't be removed from the disk at all. Tracer is an auxiliary tool
// used to track all insert and delete operations of trie and capture all
// deleted nodes eventually.
//
// The changed nodes can be mainly divided into two categories: the leaf
// node and intermediate node. The former is inserted/deleted by callers
// while the latter is inserted/deleted in order to follow the rule of trie.
// This tool can track all of them no matter the node is embedded in its
// parent or not, but valueNode is never tracked.
//
// Besides, it's also used for recording the original value of the nodes
// when they are resolved from the disk. The pre-value of the nodes will
// be used to construct reverse-diffs in the future.
//
// Note tracer is not thread-safe, callers should be responsible for handling
// the concurrency issues by themselves.
type tracer struct {
insert map[string]struct{}
delete map[string]struct{}
origin map[string][]byte
}
// newTracer initializes the tracer for capturing trie changes.
func newTracer() *tracer {
return &tracer{
insert: make(map[string]struct{}),
delete: make(map[string]struct{}),
origin: make(map[string][]byte),
}
}
// onRead tracks the newly loaded trie node and caches the rlp-encoded blob internally.
// Don't change the value outside of function since it's not deep-copied.
func (t *tracer) onRead(path []byte, val []byte) {
// Tracer isn't used right now, remove this check later.
if t == nil {
return
}
t.origin[string(path)] = val
}
// onInsert tracks the newly inserted trie node. If it's already in the deletion set
// (resurrected node), then just wipe it from the deletion set as the "untouched".
func (t *tracer) onInsert(path []byte) {
// Tracer isn't used right now, remove this check later.
if t == nil {
return
}
if _, present := t.delete[string(path)]; present {
delete(t.delete, string(path))
return
}
t.insert[string(path)] = struct{}{}
}
// onDelete tracks the newly deleted trie node. If it's already
// in the addition set, then just wipe it from the addition set
// as it's untouched.
func (t *tracer) onDelete(path []byte) {
// Tracer isn't used right now, remove this check later.
if t == nil {
return
}
if _, present := t.insert[string(path)]; present {
delete(t.insert, string(path))
return
}
t.delete[string(path)] = struct{}{}
}
// insertList returns the tracked inserted trie nodes in list format.
func (t *tracer) insertList() [][]byte {
// Tracer isn't used right now, remove this check later.
if t == nil {
return nil
}
var ret [][]byte
for path := range t.insert {
ret = append(ret, []byte(path))
}
return ret
}
// deleteList returns the tracked deleted trie nodes in list format.
func (t *tracer) deleteList() [][]byte {
// Tracer isn't used right now, remove this check later.
if t == nil {
return nil
}
var ret [][]byte
for path := range t.delete {
ret = append(ret, []byte(path))
}
return ret
}
// prevList returns the tracked node blobs in list format.
func (t *tracer) prevList() ([][]byte, [][]byte) {
// Tracer isn't used right now, remove this check later.
if t == nil {
return nil, nil
}
var (
paths [][]byte
blobs [][]byte
)
for path, blob := range t.origin {
paths = append(paths, []byte(path))
blobs = append(blobs, blob)
}
return paths, blobs
}
// getPrev returns the cached original value of the specified node.
func (t *tracer) getPrev(path []byte) []byte {
// Tracer isn't used right now, remove this check later.
if t == nil {
return nil
}
return t.origin[string(path)]
}
// reset clears the content tracked by tracer.
func (t *tracer) reset() {
// Tracer isn't used right now, remove this check later.
if t == nil {
return
}
t.insert = make(map[string]struct{})
t.delete = make(map[string]struct{})
t.origin = make(map[string][]byte)
}
// copy returns a deep copied tracer instance.
func (t *tracer) copy() *tracer {
// Tracer isn't used right now, remove this check later.
if t == nil {
return nil
}
var (
insert = make(map[string]struct{})
delete = make(map[string]struct{})
origin = make(map[string][]byte)
)
for key := range t.insert {
insert[key] = struct{}{}
}
for key := range t.delete {
delete[key] = struct{}{}
}
for key, val := range t.origin {
origin[key] = val
}
return &tracer{
insert: insert,
delete: delete,
origin: origin,
}
}