1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768 |
- // Copyright 2017 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 vm
- import "math/big"
- var checkVal = big.NewInt(-42)
- const poolLimit = 256
- // intPool is a pool of big integers that
- // can be reused for all big.Int operations.
- type intPool struct {
- pool *Stack
- }
- func newIntPool() *intPool {
- return &intPool{pool: newstack()}
- }
- // get retrieves a big int from the pool, allocating one if the pool is empty.
- // Note, the returned int's value is arbitrary and will not be zeroed!
- func (p *intPool) get() *big.Int {
- if p.pool.len() > 0 {
- return p.pool.pop()
- }
- return new(big.Int)
- }
- // getZero retrieves a big int from the pool, setting it to zero or allocating
- // a new one if the pool is empty.
- func (p *intPool) getZero() *big.Int {
- if p.pool.len() > 0 {
- return p.pool.pop().SetUint64(0)
- }
- return new(big.Int)
- }
- // put returns an allocated big int to the pool to be later reused by get calls.
- // Note, the values as saved as is; neither put nor get zeroes the ints out!
- func (p *intPool) put(is ...*big.Int) {
- if len(p.pool.data) > poolLimit {
- return
- }
- for _, i := range is {
- // verifyPool is a build flag. Pool verification makes sure the integrity
- // of the integer pool by comparing values to a default value.
- if verifyPool {
- i.Set(checkVal)
- }
- p.pool.push(i)
- }
- }
|