package state import ( "bytes" "fmt" "sort" "strings" . "github.com/tendermint/tendermint/common" "github.com/tendermint/tendermint/merkle" ) // ValidatorSet represent a set of *Validator at a given height. // The validators can be fetched by address or index. // The index is in order of .Address, so the indices are fixed // for all rounds of a given blockchain height. // On the other hand, the .AccumPower of each validator and // the designated .Proposer() of a set changes every round, // upon calling .IncrementAccum(). // NOTE: Not goroutine-safe. // NOTE: All get/set to validators should copy the value for safety. // TODO: consider validator Accum overflow // TODO: replace validators []*Validator with github.com/jaekwon/go-ibbs? type ValidatorSet struct { Validators []*Validator // NOTE: persisted via reflect, must be exported. // cached (unexported) proposer *Validator totalVotingPower uint64 } func NewValidatorSet(vals []*Validator) *ValidatorSet { validators := make([]*Validator, len(vals)) for i, val := range vals { validators[i] = val.Copy() } sort.Sort(ValidatorsByAddress(validators)) return &ValidatorSet{ Validators: validators, } } // TODO: mind the overflow when times and votingPower shares too large. func (valSet *ValidatorSet) IncrementAccum(times uint) { // Add VotingPower * times to each validator and order into heap. validatorsHeap := NewHeap() for _, val := range valSet.Validators { val.Accum += int64(val.VotingPower) * int64(times) // TODO: mind overflow validatorsHeap.Push(val, accumComparable(val.Accum)) } // Decrement the validator with most accum, times times. for i := uint(0); i < times; i++ { mostest := validatorsHeap.Peek().(*Validator) mostest.Accum -= int64(valSet.TotalVotingPower()) validatorsHeap.Update(mostest, accumComparable(mostest.Accum)) } // The next proposer is the next most accums remaining valSet.proposer = validatorsHeap.Peek().(*Validator) } func (valSet *ValidatorSet) Copy() *ValidatorSet { validators := make([]*Validator, len(valSet.Validators)) for i, val := range valSet.Validators { // NOTE: must copy, since IncrementAccum updates in place. validators[i] = val.Copy() } return &ValidatorSet{ Validators: validators, proposer: valSet.proposer, totalVotingPower: valSet.totalVotingPower, } } func (valSet *ValidatorSet) HasAddress(address []byte) bool { idx := sort.Search(len(valSet.Validators), func(i int) bool { return bytes.Compare(address, valSet.Validators[i].Address) <= 0 }) return idx != len(valSet.Validators) && bytes.Compare(valSet.Validators[idx].Address, address) == 0 } func (valSet *ValidatorSet) GetByAddress(address []byte) (index uint, val *Validator) { idx := sort.Search(len(valSet.Validators), func(i int) bool { return bytes.Compare(address, valSet.Validators[i].Address) <= 0 }) if idx != len(valSet.Validators) && bytes.Compare(valSet.Validators[idx].Address, address) == 0 { return uint(idx), valSet.Validators[idx].Copy() } else { return 0, nil } } func (valSet *ValidatorSet) GetByIndex(index uint) (address []byte, val *Validator) { val = valSet.Validators[index] return val.Address, val.Copy() } func (valSet *ValidatorSet) Size() uint { return uint(len(valSet.Validators)) } func (valSet *ValidatorSet) TotalVotingPower() uint64 { if valSet.totalVotingPower == 0 { for _, val := range valSet.Validators { valSet.totalVotingPower += val.VotingPower } } return valSet.totalVotingPower } func (valSet *ValidatorSet) Proposer() (proposer *Validator) { if valSet.proposer == nil { for _, val := range valSet.Validators { valSet.proposer = valSet.proposer.CompareAccum(val) } } return valSet.proposer.Copy() } func (valSet *ValidatorSet) Hash() []byte { if len(valSet.Validators) == 0 { return nil } hashables := make([]merkle.Hashable, len(valSet.Validators)) for i, val := range valSet.Validators { hashables[i] = val } return merkle.HashFromHashables(hashables) } func (valSet *ValidatorSet) Add(val *Validator) (added bool) { val = val.Copy() idx := sort.Search(len(valSet.Validators), func(i int) bool { return bytes.Compare(val.Address, valSet.Validators[i].Address) <= 0 }) if idx == len(valSet.Validators) { valSet.Validators = append(valSet.Validators, val) // Invalidate cache valSet.proposer = nil valSet.totalVotingPower = 0 return true } else if bytes.Compare(valSet.Validators[idx].Address, val.Address) == 0 { return false } else { newValidators := make([]*Validator, len(valSet.Validators)+1) copy(newValidators[:idx], valSet.Validators[:idx]) newValidators[idx] = val copy(newValidators[idx+1:], valSet.Validators[idx:]) valSet.Validators = newValidators // Invalidate cache valSet.proposer = nil valSet.totalVotingPower = 0 return true } } func (valSet *ValidatorSet) Update(val *Validator) (updated bool) { index, sameVal := valSet.GetByAddress(val.Address) if sameVal == nil { return false } else { valSet.Validators[index] = val.Copy() // Invalidate cache valSet.proposer = nil valSet.totalVotingPower = 0 return true } } func (valSet *ValidatorSet) Remove(address []byte) (val *Validator, removed bool) { idx := sort.Search(len(valSet.Validators), func(i int) bool { return bytes.Compare(address, valSet.Validators[i].Address) <= 0 }) if idx == len(valSet.Validators) || bytes.Compare(valSet.Validators[idx].Address, address) != 0 { return nil, false } else { removedVal := valSet.Validators[idx] newValidators := valSet.Validators[:idx] if idx+1 < len(valSet.Validators) { newValidators = append(newValidators, valSet.Validators[idx+1:]...) } valSet.Validators = newValidators // Invalidate cache valSet.proposer = nil valSet.totalVotingPower = 0 return removedVal, true } } func (valSet *ValidatorSet) Iterate(fn func(index uint, val *Validator) bool) { for i, val := range valSet.Validators { stop := fn(uint(i), val.Copy()) if stop { break } } } func (valSet *ValidatorSet) String() string { return valSet.StringIndented("") } func (valSet *ValidatorSet) StringIndented(indent string) string { valStrings := []string{} valSet.Iterate(func(index uint, val *Validator) bool { valStrings = append(valStrings, val.String()) return false }) return fmt.Sprintf(`ValidatorSet{ %s Proposer: %v %s Validators: %s %v %s}`, indent, valSet.Proposer().String(), indent, indent, strings.Join(valStrings, "\n"+indent+" "), indent) } //------------------------------------- // Implements sort for sorting validators by address. type ValidatorsByAddress []*Validator func (vs ValidatorsByAddress) Len() int { return len(vs) } func (vs ValidatorsByAddress) Less(i, j int) bool { return bytes.Compare(vs[i].Address, vs[j].Address) == -1 } func (vs ValidatorsByAddress) Swap(i, j int) { it := vs[i] vs[i] = vs[j] vs[j] = it } //------------------------------------- // Use with Heap for sorting validators by accum type accumComparable uint64 // We want to find the validator with the greatest accum. func (ac accumComparable) Less(o interface{}) bool { return uint64(ac) > uint64(o.(accumComparable)) }