// Copyright 2016 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 core
import (
"container/heap"
"math"
"math/big"
"sort"
"github.com/ava-labs/coreth/core/types"
"github.com/ava-labs/go-ethereum/common"
"github.com/ava-labs/go-ethereum/log"
)
// nonceHeap is a heap.Interface implementation over 64bit unsigned integers for
// retrieving sorted transactions from the possibly gapped future queue.
type nonceHeap []uint64
func (h nonceHeap) Len() int { return len(h) }
func (h nonceHeap) Less(i, j int) bool { return h[i] < h[j] }
func (h nonceHeap) Swap(i, j int) { h[i], h[j] = h[j], h[i] }
func (h *nonceHeap) Push(x interface{}) {
*h = append(*h, x.(uint64))
}
func (h *nonceHeap) Pop() interface{} {
old := *h
n := len(old)
x := old[n-1]
*h = old[0 : n-1]
return x
}
// txSortedMap is a nonce->transaction hash map with a heap based index to allow
// iterating over the contents in a nonce-incrementing way.
type txSortedMap struct {
items map[uint64]*types.Transaction // Hash map storing the transaction data
index *nonceHeap // Heap of nonces of all the stored transactions (non-strict mode)
cache types.Transactions // Cache of the transactions already sorted
}
// newTxSortedMap creates a new nonce-sorted transaction map.
func newTxSortedMap() *txSortedMap {
return &txSortedMap{
items: make(map[uint64]*types.Transaction),
index: new(nonceHeap),
}
}
// Get retrieves the current transactions associated with the given nonce.
func (m *txSortedMap) Get(nonce uint64) *types.Transaction {
return m.items[nonce]
}
// Put inserts a new transaction into the map, also updating the map's nonce
// index. If a transaction already exists with the same nonce, it's overwritten.
func (m *txSortedMap) Put(tx *types.Transaction) {
nonce := tx.Nonce()
if m.items[nonce] == nil {
heap.Push(m.index, nonce)
}
m.items[nonce], m.cache = tx, nil
}
// Forward removes all transactions from the map with a nonce lower than the
// provided threshold. Every removed transaction is returned for any post-removal
// maintenance.
func (m *txSortedMap) Forward(threshold uint64) types.Transactions {
var removed types.Transactions
// Pop off heap items until the threshold is reached
for m.index.Len() > 0 && (*m.index)[0] < threshold {
nonce := heap.Pop(m.index).(uint64)
removed = append(removed, m.items[nonce])
delete(m.items, nonce)
}
// If we had a cached order, shift the front
if m.cache != nil {
m.cache = m.cache[len(removed):]
}
return removed
}
// Filter iterates over the list of transactions and removes all of them for which
// the specified function evaluates to true.
func (m *txSortedMap) Filter(filter func(*types.Transaction) bool) types.Transactions {
var removed types.Transactions
// Collect all the transactions to filter out
for nonce, tx := range m.items {
if filter(tx) {
removed = append(removed, tx)
delete(m.items, nonce)
}
}
// If transactions were removed, the heap and cache are ruined
if len(removed) > 0 {
*m.index = make([]uint64, 0, len(m.items))
for nonce := range m.items {
*m.index = append(*m.index, nonce)
}
heap.Init(m.index)
m.cache = nil
}
return removed
}
// Cap places a hard limit on the number of items, returning all transactions
// exceeding that limit.
func (m *txSortedMap) Cap(threshold int) types.Transactions {
// Short circuit if the number of items is under the limit
if len(m.items) <= threshold {
return nil
}
// Otherwise gather and drop the highest nonce'd transactions
var drops types.Transactions
sort.Sort(*m.index)
for size := len(m.items); size > threshold; size-- {
drops = append(drops, m.items[(*m.index)[size-1]])
delete(m.items, (*m.index)[size-1])
}
*m.index = (*m.index)[:threshold]
heap.Init(m.index)
// If we had a cache, shift the back
if m.cache != nil {
m.cache = m.cache[:len(m.cache)-len(drops)]
}
return drops
}
// Remove deletes a transaction from the maintained map, returning whether the
// transaction was found.
func (m *txSortedMap) Remove(nonce uint64) bool {
// Short circuit if no transaction is present
_, ok := m.items[nonce]
if !ok {
return false
}
// Otherwise delete the transaction and fix the heap index
for i := 0; i < m.index.Len(); i++ {
if (*m.index)[i] == nonce {
heap.Remove(m.index, i)
break
}
}
delete(m.items, nonce)
m.cache = nil
return true
}
// Ready retrieves a sequentially increasing list of transactions starting at the
// provided nonce that is ready for processing. The returned transactions will be
// removed from the list.
//
// Note, all transactions with nonces lower than start will also be returned to
// prevent getting into and invalid state. This is not something that should ever
// happen but better to be self correcting than failing!
func (m *txSortedMap) Ready(start uint64) types.Transactions {
// Short circuit if no transactions are available
if m.index.Len() == 0 || (*m.index)[0] > start {
return nil
}
// Otherwise start accumulating incremental transactions
var ready types.Transactions
for next := (*m.index)[0]; m.index.Len() > 0 && (*m.index)[0] == next; next++ {
ready = append(ready, m.items[next])
delete(m.items, next)
heap.Pop(m.index)
}
m.cache = nil
return ready
}
// Len returns the length of the transaction map.
func (m *txSortedMap) Len() int {
return len(m.items)
}
// Flatten creates a nonce-sorted slice of transactions based on the loosely
// sorted internal representation. The result of the sorting is cached in case
// it's requested again before any modifications are made to the contents.
func (m *txSortedMap) Flatten() types.Transactions {
// If the sorting was not cached yet, create and cache it
if m.cache == nil {
m.cache = make(types.Transactions, 0, len(m.items))
for _, tx := range m.items {
m.cache = append(m.cache, tx)
}
sort.Sort<