cubefs

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// Copyright 2019 The Prometheus Authors
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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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package procfs
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import (
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	"bufio"
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	"bytes"
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	"fmt"
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	"strconv"
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	"strings"
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	"github.com/prometheus/procfs/internal/util"
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)
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// Swap represents an entry in /proc/swaps.
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type Swap struct {
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	Filename string
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	Type     string
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	Size     int
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	Used     int
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	Priority int
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}
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// Swaps returns a slice of all configured swap devices on the system.
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func (fs FS) Swaps() ([]*Swap, error) {
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	data, err := util.ReadFileNoStat(fs.proc.Path("swaps"))
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	if err != nil {
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		return nil, err
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	}
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	return parseSwaps(data)
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}
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func parseSwaps(info []byte) ([]*Swap, error) {
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	swaps := []*Swap{}
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	scanner := bufio.NewScanner(bytes.NewReader(info))
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	scanner.Scan() // ignore header line
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	for scanner.Scan() {
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		swapString := scanner.Text()
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		parsedSwap, err := parseSwapString(swapString)
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		if err != nil {
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			return nil, err
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		}
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		swaps = append(swaps, parsedSwap)
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	}
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	err := scanner.Err()
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	return swaps, err
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}
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func parseSwapString(swapString string) (*Swap, error) {
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	var err error
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	swapFields := strings.Fields(swapString)
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	swapLength := len(swapFields)
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	if swapLength < 5 {
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		return nil, fmt.Errorf("too few fields in swap string: %s", swapString)
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	}
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	swap := &Swap{
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		Filename: swapFields[0],
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		Type:     swapFields[1],
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	}
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	swap.Size, err = strconv.Atoi(swapFields[2])
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	if err != nil {
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		return nil, fmt.Errorf("invalid swap size: %s", swapFields[2])
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	}
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	swap.Used, err = strconv.Atoi(swapFields[3])
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	if err != nil {
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		return nil, fmt.Errorf("invalid swap used: %s", swapFields[3])
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	}
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	swap.Priority, err = strconv.Atoi(swapFields[4])
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	if err != nil {
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		return nil, fmt.Errorf("invalid swap priority: %s", swapFields[4])
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	}
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	return swap, nil
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}
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