/usr/share/gocode/src/github.com/bsm/pool/pool.go is in golang-github-bsm-pool-dev 0.8.0-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 | // Package pool is a generic, high-performance pool for net.Conn
// objects.
package pool
import (
"net"
"sync"
"sync/atomic"
"time"
)
// Factory must returns new connections
type Factory func() (net.Conn, error)
// Options can tweak Pool configuration
type Options struct {
// InitialSize creates a number of connection on pool initialization
// Default: 0
InitialSize int
// MaxCap sets the maximum pool capacity. Will be automatically adjusted when InitialSize
// is larger.
// Default: 10
MaxCap int
// IdleTimeout timeout after which connections are reaped and
// automatically removed from the pool.
// Default: 0 (= never)
IdleTimeout time.Duration
// ReapInterval determines the frequency of reap cycles
// Default: 1 minute
ReapInterval time.Duration
}
func (o *Options) norm() Options {
x := *o
if x.ReapInterval <= 0 {
x.ReapInterval = time.Minute
}
if x.MaxCap <= 0 {
x.MaxCap = 10
}
if x.MaxCap < x.InitialSize {
x.MaxCap = x.InitialSize
}
return x
}
type none struct{}
// Pool contains a number of connections
type Pool struct {
conns []member
opt Options
factory Factory
dying, dead chan none
avail uint32
closed int32
mu sync.Mutex
}
// New creates a pool with an initial number of connection and a maximum cap
func New(opt *Options, factory Factory) (*Pool, error) {
if opt == nil {
opt = new(Options)
}
p := &Pool{
conns: make([]member, 0, opt.MaxCap),
factory: factory,
opt: opt.norm(),
dying: make(chan none),
dead: make(chan none),
}
for i := 0; i < opt.InitialSize; i++ {
cn, err := factory()
if err != nil {
_ = p.close()
return nil, err
}
p.Put(cn)
}
go p.loop()
return p, nil
}
// Len returns the number of available connections in the pool
func (s *Pool) Len() int { return int(atomic.LoadUint32(&s.avail)) }
// Get returns a connection from the pool or creates a new one
func (s *Pool) Get() (net.Conn, error) {
if cn := s.pop(); cn != nil {
return cn, nil
}
return s.factory()
}
// Put adds/returns a connection to the pool
func (s *Pool) Put(cn net.Conn) bool {
if s.Len() >= s.opt.MaxCap || atomic.LoadInt32(&s.closed) == 1 {
_ = cn.Close()
return false
}
m := member{cn: cn, lastAccess: time.Now()}
s.mu.Lock()
s.conns = append(s.conns, m)
atomic.StoreUint32(&s.avail, uint32(len(s.conns)))
s.mu.Unlock()
return true
}
// Close closes all connections and the pool
func (s *Pool) Close() error {
if !atomic.CompareAndSwapInt32(&s.closed, 0, 1) {
return nil
}
close(s.dying)
<-s.dead
return s.close()
}
func (s *Pool) pop() net.Conn {
s.mu.Lock()
pos := len(s.conns) - 1
if pos < 0 {
s.mu.Unlock()
return nil
}
m := s.conns[pos]
s.conns = s.conns[:pos]
atomic.StoreUint32(&s.avail, uint32(len(s.conns)))
s.mu.Unlock()
return m.cn
}
func (s *Pool) close() (err error) {
for {
cn := s.pop()
if cn == nil {
break
}
if e := cn.Close(); e != nil {
err = e
}
}
return err
}
func (s *Pool) reap() {
timeout := s.opt.IdleTimeout
if timeout <= 0 {
return
}
cutoff := time.Now().Add(-timeout)
s.mu.Lock()
if sz := len(s.conns); sz != 0 {
if m := s.conns[0]; m.lastAccess.Before(cutoff) {
defer m.cn.Close()
copy(s.conns, s.conns[1:])
s.conns = s.conns[:sz-1]
atomic.StoreUint32(&s.avail, uint32(len(s.conns)))
}
}
s.mu.Unlock()
}
func (s *Pool) loop() {
defer close(s.dead)
ticker := time.NewTicker(s.opt.ReapInterval)
defer ticker.Stop()
for {
select {
case <-s.dying:
return
case <-ticker.C:
s.reap()
}
}
}
type member struct {
cn net.Conn
lastAccess time.Time
}
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