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package client
import (
"net"
"sync"
"sync/atomic"
"time"
)
// Chanel number:
// 0x4000 through 0x7FFF: These values are the allowed channel
// numbers (16,383 possible values).
const (
minChannelNumber uint16 = 0x4000
maxChannelNumber uint16 = 0x7fff
)
type bindingState int32
const (
bindingStateIdle bindingState = iota
bindingStateRequest
bindingStateReady
bindingStateRefresh
bindingStateFailed
)
type binding struct {
number uint16 // read-only
st bindingState // thread-safe (atomic op)
addr net.Addr // read-only
mgr *bindingManager // read-only
muBind sync.Mutex // thread-safe, for ChannelBind ops
_refreshedAt time.Time // protected by mutex
mutex sync.RWMutex // thread-safe
}
func (b *binding) setState(state bindingState) {
atomic.StoreInt32((*int32)(&b.st), int32(state))
}
func (b *binding) state() bindingState {
return bindingState(atomic.LoadInt32((*int32)(&b.st)))
}
func (b *binding) setRefreshedAt(at time.Time) {
b.mutex.Lock()
defer b.mutex.Unlock()
b._refreshedAt = at
}
func (b *binding) refreshedAt() time.Time {
b.mutex.RLock()
defer b.mutex.RUnlock()
return b._refreshedAt
}
// Thread-safe binding map
type bindingManager struct {
chanMap map[uint16]*binding
addrMap map[string]*binding
next uint16
mutex sync.RWMutex
}
func newBindingManager() *bindingManager {
return &bindingManager{
chanMap: map[uint16]*binding{},
addrMap: map[string]*binding{},
next: minChannelNumber,
}
}
func (mgr *bindingManager) assignChannelNumber() uint16 {
n := mgr.next
if mgr.next == maxChannelNumber {
mgr.next = minChannelNumber
} else {
mgr.next++
}
return n
}
func (mgr *bindingManager) create(addr net.Addr) *binding {
mgr.mutex.Lock()
defer mgr.mutex.Unlock()
b := &binding{
number: mgr.assignChannelNumber(),
addr: addr,
mgr: mgr,
_refreshedAt: time.Now(),
}
mgr.chanMap[b.number] = b
mgr.addrMap[b.addr.String()] = b
return b
}
func (mgr *bindingManager) findByAddr(addr net.Addr) (*binding, bool) {
mgr.mutex.RLock()
defer mgr.mutex.RUnlock()
b, ok := mgr.addrMap[addr.String()]
return b, ok
}
func (mgr *bindingManager) findByNumber(number uint16) (*binding, bool) {
mgr.mutex.RLock()
defer mgr.mutex.RUnlock()
b, ok := mgr.chanMap[number]
return b, ok
}
func (mgr *bindingManager) deleteByAddr(addr net.Addr) bool {
mgr.mutex.Lock()
defer mgr.mutex.Unlock()
b, ok := mgr.addrMap[addr.String()]
if !ok {
return false
}
delete(mgr.addrMap, addr.String())
delete(mgr.chanMap, b.number)
return true
}
func (mgr *bindingManager) deleteByNumber(number uint16) bool {
mgr.mutex.Lock()
defer mgr.mutex.Unlock()
b, ok := mgr.chanMap[number]
if !ok {
return false
}
delete(mgr.addrMap, b.addr.String())
delete(mgr.chanMap, number)
return true
}
func (mgr *bindingManager) size() int {
mgr.mutex.RLock()
defer mgr.mutex.RUnlock()
return len(mgr.chanMap)
}
|