cubefs

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// Copyright 2018 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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	"io"
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	"strconv"
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	"strings"
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	"github.com/prometheus/procfs/internal/fs"
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	"github.com/prometheus/procfs/internal/util"
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)
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// CPUStat shows how much time the cpu spend in various stages.
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type CPUStat struct {
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	User      float64
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	Nice      float64
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	System    float64
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	Idle      float64
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	Iowait    float64
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	IRQ       float64
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	SoftIRQ   float64
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	Steal     float64
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	Guest     float64
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	GuestNice float64
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}
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// SoftIRQStat represent the softirq statistics as exported in the procfs stat file.
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// A nice introduction can be found at https://0xax.gitbooks.io/linux-insides/content/interrupts/interrupts-9.html
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// It is possible to get per-cpu stats by reading `/proc/softirqs`.
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type SoftIRQStat struct {
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	Hi          uint64
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	Timer       uint64
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	NetTx       uint64
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	NetRx       uint64
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	Block       uint64
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	BlockIoPoll uint64
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	Tasklet     uint64
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	Sched       uint64
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	Hrtimer     uint64
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	Rcu         uint64
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}
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// Stat represents kernel/system statistics.
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type Stat struct {
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	// Boot time in seconds since the Epoch.
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	BootTime uint64
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	// Summed up cpu statistics.
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	CPUTotal CPUStat
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	// Per-CPU statistics.
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	CPU []CPUStat
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	// Number of times interrupts were handled, which contains numbered and unnumbered IRQs.
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	IRQTotal uint64
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	// Number of times a numbered IRQ was triggered.
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	IRQ []uint64
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	// Number of times a context switch happened.
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	ContextSwitches uint64
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	// Number of times a process was created.
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	ProcessCreated uint64
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	// Number of processes currently running.
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	ProcessesRunning uint64
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	// Number of processes currently blocked (waiting for IO).
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	ProcessesBlocked uint64
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	// Number of times a softirq was scheduled.
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	SoftIRQTotal uint64
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	// Detailed softirq statistics.
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	SoftIRQ SoftIRQStat
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}
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// Parse a cpu statistics line and returns the CPUStat struct plus the cpu id (or -1 for the overall sum).
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func parseCPUStat(line string) (CPUStat, int64, error) {
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	cpuStat := CPUStat{}
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	var cpu string
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	count, err := fmt.Sscanf(line, "%s %f %f %f %f %f %f %f %f %f %f",
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		&cpu,
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		&cpuStat.User, &cpuStat.Nice, &cpuStat.System, &cpuStat.Idle,
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		&cpuStat.Iowait, &cpuStat.IRQ, &cpuStat.SoftIRQ, &cpuStat.Steal,
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		&cpuStat.Guest, &cpuStat.GuestNice)
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	if err != nil && err != io.EOF {
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		return CPUStat{}, -1, fmt.Errorf("couldn't parse %q (cpu): %w", line, err)
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	}
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	if count == 0 {
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		return CPUStat{}, -1, fmt.Errorf("couldn't parse %q (cpu): 0 elements parsed", line)
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	}
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	cpuStat.User /= userHZ
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	cpuStat.Nice /= userHZ
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	cpuStat.System /= userHZ
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	cpuStat.Idle /= userHZ
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	cpuStat.Iowait /= userHZ
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	cpuStat.IRQ /= userHZ
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	cpuStat.SoftIRQ /= userHZ
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	cpuStat.Steal /= userHZ
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	cpuStat.Guest /= userHZ
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	cpuStat.GuestNice /= userHZ
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	if cpu == "cpu" {
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		return cpuStat, -1, nil
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	}
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	cpuID, err := strconv.ParseInt(cpu[3:], 10, 64)
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	if err != nil {
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		return CPUStat{}, -1, fmt.Errorf("couldn't parse %q (cpu/cpuid): %w", line, err)
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	}
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	return cpuStat, cpuID, nil
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}
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// Parse a softirq line.
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func parseSoftIRQStat(line string) (SoftIRQStat, uint64, error) {
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	softIRQStat := SoftIRQStat{}
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	var total uint64
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	var prefix string
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	_, err := fmt.Sscanf(line, "%s %d %d %d %d %d %d %d %d %d %d %d",
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		&prefix, &total,
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		&softIRQStat.Hi, &softIRQStat.Timer, &softIRQStat.NetTx, &softIRQStat.NetRx,
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		&softIRQStat.Block, &softIRQStat.BlockIoPoll,
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		&softIRQStat.Tasklet, &softIRQStat.Sched,
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		&softIRQStat.Hrtimer, &softIRQStat.Rcu)
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	if err != nil {
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		return SoftIRQStat{}, 0, fmt.Errorf("couldn't parse %q (softirq): %w", line, err)
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	}
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	return softIRQStat, total, nil
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}
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// NewStat returns information about current cpu/process statistics.
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// See https://www.kernel.org/doc/Documentation/filesystems/proc.txt
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//
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// Deprecated: Use fs.Stat() instead.
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func NewStat() (Stat, error) {
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	fs, err := NewFS(fs.DefaultProcMountPoint)
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	if err != nil {
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		return Stat{}, err
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	}
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	return fs.Stat()
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}
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// NewStat returns information about current cpu/process statistics.
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// See: https://www.kernel.org/doc/Documentation/filesystems/proc.txt
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//
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// Deprecated: Use fs.Stat() instead.
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func (fs FS) NewStat() (Stat, error) {
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	return fs.Stat()
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}
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// Stat returns information about current cpu/process statistics.
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// See: https://www.kernel.org/doc/Documentation/filesystems/proc.txt
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func (fs FS) Stat() (Stat, error) {
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	fileName := fs.proc.Path("stat")
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	data, err := util.ReadFileNoStat(fileName)
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	if err != nil {
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		return Stat{}, err
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	}
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	stat := Stat{}
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	scanner := bufio.NewScanner(bytes.NewReader(data))
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	for scanner.Scan() {
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		line := scanner.Text()
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		parts := strings.Fields(scanner.Text())
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		// require at least <key> <value>
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		if len(parts) < 2 {
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			continue
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		}
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		switch {
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		case parts[0] == "btime":
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			if stat.BootTime, err = strconv.ParseUint(parts[1], 10, 64); err != nil {
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				return Stat{}, fmt.Errorf("couldn't parse %q (btime): %w", parts[1], err)
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			}
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		case parts[0] == "intr":
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			if stat.IRQTotal, err = strconv.ParseUint(parts[1], 10, 64); err != nil {
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				return Stat{}, fmt.Errorf("couldn't parse %q (intr): %w", parts[1], err)
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			}
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			numberedIRQs := parts[2:]
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			stat.IRQ = make([]uint64, len(numberedIRQs))
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			for i, count := range numberedIRQs {
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				if stat.IRQ[i], err = strconv.ParseUint(count, 10, 64); err != nil {
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					return Stat{}, fmt.Errorf("couldn't parse %q (intr%d): %w", count, i, err)
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				}
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			}
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		case parts[0] == "ctxt":
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			if stat.ContextSwitches, err = strconv.ParseUint(parts[1], 10, 64); err != nil {
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				return Stat{}, fmt.Errorf("couldn't parse %q (ctxt): %w", parts[1], err)
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			}
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		case parts[0] == "processes":
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			if stat.ProcessCreated, err = strconv.ParseUint(parts[1], 10, 64); err != nil {
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				return Stat{}, fmt.Errorf("couldn't parse %q (processes): %w", parts[1], err)
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			}
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		case parts[0] == "procs_running":
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			if stat.ProcessesRunning, err = strconv.ParseUint(parts[1], 10, 64); err != nil {
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				return Stat{}, fmt.Errorf("couldn't parse %q (procs_running): %w", parts[1], err)
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			}
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		case parts[0] == "procs_blocked":
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			if stat.ProcessesBlocked, err = strconv.ParseUint(parts[1], 10, 64); err != nil {
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				return Stat{}, fmt.Errorf("couldn't parse %q (procs_blocked): %w", parts[1], err)
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			}
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		case parts[0] == "softirq":
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			softIRQStats, total, err := parseSoftIRQStat(line)
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			if err != nil {
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				return Stat{}, err
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			}
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			stat.SoftIRQTotal = total
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			stat.SoftIRQ = softIRQStats
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		case strings.HasPrefix(parts[0], "cpu"):
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			cpuStat, cpuID, err := parseCPUStat(line)
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			if err != nil {
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				return Stat{}, err
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			}
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			if cpuID == -1 {
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				stat.CPUTotal = cpuStat
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			} else {
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				for int64(len(stat.CPU)) <= cpuID {
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					stat.CPU = append(stat.CPU, CPUStat{})
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				}
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				stat.CPU[cpuID] = cpuStat
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			}
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		}
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	}
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	if err := scanner.Err(); err != nil {
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		return Stat{}, fmt.Errorf("couldn't parse %q: %w", fileName, err)
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	}
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	return stat, nil
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}
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