/
intpool.go
91 lines (76 loc) · 1.99 KB
/
intpool.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
package vm
import (
"math/big"
"sync"
)
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.
verifyPool := false
if verifyPool {
i.Set(checkVal)
}
p.pool.push(i)
}
}
// The intPool pool's default capacity
const poolDefaultCap = 25
// intPoolPool manages a pool of intPools.
type intPoolPool struct {
pools []*intPool
lock sync.Mutex
}
var poolOfIntPools = &intPoolPool{
pools: make([]*intPool, 0, poolDefaultCap),
}
// get is looking for an available pool to return.
func (ipp *intPoolPool) get() *intPool {
ipp.lock.Lock()
defer ipp.lock.Unlock()
if len(poolOfIntPools.pools) > 0 {
ip := ipp.pools[len(ipp.pools)-1]
ipp.pools = ipp.pools[:len(ipp.pools)-1]
return ip
}
return newIntPool()
}
// put a pool that has been allocated with get.
func (ipp *intPoolPool) put(ip *intPool) {
ipp.lock.Lock()
defer ipp.lock.Unlock()
if len(ipp.pools) < cap(ipp.pools) {
ipp.pools = append(ipp.pools, ip)
}
}