prysm-pulse/beacon-chain/state/v2/field_trie.go
terence tsao 54772596e0
State/V2: rest of pkg (#9283)
* Add rest of state v2

* Update BUILD.bazel
2021-07-27 15:47:03 +00:00

192 lines
5.9 KiB
Go

package v2
import (
"reflect"
"sync"
"github.com/pkg/errors"
"github.com/prysmaticlabs/prysm/beacon-chain/state/stateutil"
v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
)
// FieldTrie is the representation of the representative
// trie of the particular field.
type FieldTrie struct {
*sync.RWMutex
reference *stateutil.Reference
fieldLayers [][]*[32]byte
field fieldIndex
length uint64
}
// NewFieldTrie is the constructor for the field trie data structure. It creates the corresponding
// trie according to the given parameters. Depending on whether the field is a basic/composite array
// which is either fixed/variable length, it will appropriately determine the trie.
func NewFieldTrie(field fieldIndex, elements interface{}, length uint64) (*FieldTrie, error) {
if elements == nil {
return &FieldTrie{
field: field,
reference: stateutil.NewRef(1),
RWMutex: new(sync.RWMutex),
length: length,
}, nil
}
datType, ok := fieldMap[field]
if !ok {
return nil, errors.Errorf("unrecognized field in trie")
}
fieldRoots, err := fieldConverters(field, []uint64{}, elements, true)
if err != nil {
return nil, err
}
if err := validateElements(field, elements, length); err != nil {
return nil, err
}
switch datType {
case basicArray:
return &FieldTrie{
fieldLayers: stateutil.ReturnTrieLayer(fieldRoots, length),
field: field,
reference: stateutil.NewRef(1),
RWMutex: new(sync.RWMutex),
}, nil
case compositeArray:
return &FieldTrie{
fieldLayers: stateutil.ReturnTrieLayerVariable(fieldRoots, length),
field: field,
reference: stateutil.NewRef(1),
RWMutex: new(sync.RWMutex),
}, nil
default:
return nil, errors.Errorf("unrecognized data type in field map: %v", reflect.TypeOf(datType).Name())
}
}
// RecomputeTrie rebuilds the affected branches in the trie according to the provided
// changed indices and elements. This recomputes the trie according to the particular
// field the trie is based on.
func (f *FieldTrie) RecomputeTrie(indices []uint64, elements interface{}) ([32]byte, error) {
f.Lock()
defer f.Unlock()
var fieldRoot [32]byte
if len(indices) == 0 {
return f.TrieRoot()
}
datType, ok := fieldMap[f.field]
if !ok {
return [32]byte{}, errors.Errorf("unrecognized field in trie")
}
fieldRoots, err := fieldConverters(f.field, indices, elements, false)
if err != nil {
return [32]byte{}, err
}
if err := f.validateIndices(indices); err != nil {
return [32]byte{}, err
}
switch datType {
case basicArray:
fieldRoot, f.fieldLayers, err = stateutil.RecomputeFromLayer(fieldRoots, indices, f.fieldLayers)
if err != nil {
return [32]byte{}, err
}
return fieldRoot, nil
case compositeArray:
fieldRoot, f.fieldLayers, err = stateutil.RecomputeFromLayerVariable(fieldRoots, indices, f.fieldLayers)
if err != nil {
return [32]byte{}, err
}
return stateutil.AddInMixin(fieldRoot, uint64(len(f.fieldLayers[0])))
default:
return [32]byte{}, errors.Errorf("unrecognized data type in field map: %v", reflect.TypeOf(datType).Name())
}
}
// CopyTrie copies the references to the elements the trie
// is built on.
func (f *FieldTrie) CopyTrie() *FieldTrie {
if f.fieldLayers == nil {
return &FieldTrie{
field: f.field,
reference: stateutil.NewRef(1),
RWMutex: new(sync.RWMutex),
}
}
dstFieldTrie := make([][]*[32]byte, len(f.fieldLayers))
for i, layer := range f.fieldLayers {
dstFieldTrie[i] = make([]*[32]byte, len(layer))
copy(dstFieldTrie[i], layer)
}
return &FieldTrie{
fieldLayers: dstFieldTrie,
field: f.field,
reference: stateutil.NewRef(1),
RWMutex: new(sync.RWMutex),
}
}
// TrieRoot returns the corresponding root of the trie.
func (f *FieldTrie) TrieRoot() ([32]byte, error) {
datType, ok := fieldMap[f.field]
if !ok {
return [32]byte{}, errors.Errorf("unrecognized field in trie")
}
switch datType {
case basicArray:
return *f.fieldLayers[len(f.fieldLayers)-1][0], nil
case compositeArray:
trieRoot := *f.fieldLayers[len(f.fieldLayers)-1][0]
return stateutil.AddInMixin(trieRoot, uint64(len(f.fieldLayers[0])))
default:
return [32]byte{}, errors.Errorf("unrecognized data type in field map: %v", reflect.TypeOf(datType).Name())
}
}
// this converts the corresponding field and the provided elements to the appropriate roots.
func fieldConverters(field fieldIndex, indices []uint64, elements interface{}, convertAll bool) ([][32]byte, error) {
switch field {
case blockRoots, stateRoots, randaoMixes:
val, ok := elements.([][]byte)
if !ok {
return nil, errors.Errorf("Wanted type of %v but got %v",
reflect.TypeOf([][]byte{}).Name(), reflect.TypeOf(elements).Name())
}
return stateutil.HandleByteArrays(val, indices, convertAll)
case eth1DataVotes:
val, ok := elements.([]*ethpb.Eth1Data)
if !ok {
return nil, errors.Errorf("Wanted type of %v but got %v",
reflect.TypeOf([]*ethpb.Eth1Data{}).Name(), reflect.TypeOf(elements).Name())
}
return v1.HandleEth1DataSlice(val, indices, convertAll)
case validators:
val, ok := elements.([]*ethpb.Validator)
if !ok {
return nil, errors.Errorf("Wanted type of %v but got %v",
reflect.TypeOf([]*ethpb.Validator{}).Name(), reflect.TypeOf(elements).Name())
}
return stateutil.HandleValidatorSlice(val, indices, convertAll)
default:
return [][32]byte{}, errors.Errorf("got unsupported type of %v", reflect.TypeOf(elements).Name())
}
}
func (f *FieldTrie) validateIndices(idxs []uint64) error {
for _, idx := range idxs {
if idx >= f.length {
return errors.Errorf("invalid index for field %s: %d >= length %d", f.field.String(), idx, f.length)
}
}
return nil
}
func validateElements(field fieldIndex, elements interface{}, length uint64) error {
val := reflect.ValueOf(elements)
if val.Len() > int(length) {
return errors.Errorf("elements length is larger than expected for field %s: %d > %d", field.String(), val.Len(), length)
}
return nil
}