* * Copyright 2018 gRPC authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http:www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * 

package conn

import (
	
)

const counterLen = 12

var (
	errInvalidCounter = errors.New("invalid counter")
)
Counter is a 96-bit, little-endian counter.
type Counter struct {
	value       [counterLen]byte
	invalid     bool
	overflowLen int
}
Value returns the current value of the counter as a byte slice.
func ( *Counter) () ([]byte, error) {
	if .invalid {
		return nil, errInvalidCounter
	}
	return .value[:], nil
}
Inc increments the counter and checks for overflow.
If the counter is already invalid, there is no need to increase it.
	if .invalid {
		return
	}
	 := 0
	for ;  < .overflowLen; ++ {
		.value[]++
		if .value[] != 0 {
			break
		}
	}
	if  == .overflowLen {
		.invalid = true
	}