mirror of
https://github.com/rocky-linux/peridot.git
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63 lines
1.3 KiB
Go
63 lines
1.3 KiB
Go
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/*
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*
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* Copyright 2018 gRPC authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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*/
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package conn
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import (
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"errors"
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)
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const counterLen = 12
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var (
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errInvalidCounter = errors.New("invalid counter")
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)
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// Counter is a 96-bit, little-endian counter.
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type Counter struct {
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value [counterLen]byte
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invalid bool
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overflowLen int
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}
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// Value returns the current value of the counter as a byte slice.
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func (c *Counter) Value() ([]byte, error) {
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if c.invalid {
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return nil, errInvalidCounter
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}
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return c.value[:], nil
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}
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// Inc increments the counter and checks for overflow.
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func (c *Counter) Inc() {
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// If the counter is already invalid, there is no need to increase it.
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if c.invalid {
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return
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}
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i := 0
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for ; i < c.overflowLen; i++ {
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c.value[i]++
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if c.value[i] != 0 {
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break
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}
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}
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if i == c.overflowLen {
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c.invalid = true
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}
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}
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