source: code/trunk/vendor/github.com/prometheus/procfs/proc_io.go@ 822

// Copyright 2018 The Prometheus 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 procfs

import (
        "fmt"

        "github.com/prometheus/procfs/internal/util"
)

// ProcIO models the content of /proc/<pid>/io.
type ProcIO struct {
        // Chars read.
        RChar uint64
        // Chars written.
        WChar uint64
        // Read syscalls.
        SyscR uint64
        // Write syscalls.
        SyscW uint64
        // Bytes read.
        ReadBytes uint64
        // Bytes written.
        WriteBytes uint64
        // Bytes written, but taking into account truncation. See
        // Documentation/filesystems/proc.txt in the kernel sources for
        // detailed explanation.
        CancelledWriteBytes int64
}

// IO creates a new ProcIO instance from a given Proc instance.
func (p Proc) IO() (ProcIO, error) {
        pio := ProcIO{}

        data, err := util.ReadFileNoStat(p.path("io"))
        if err != nil {
                return pio, err
        }

        ioFormat := "rchar: %d\nwchar: %d\nsyscr: %d\nsyscw: %d\n" +
                "read_bytes: %d\nwrite_bytes: %d\n" +
                "cancelled_write_bytes: %d\n"

        _, err = fmt.Sscanf(string(data), ioFormat, &pio.RChar, &pio.WChar, &pio.SyscR,
                &pio.SyscW, &pio.ReadBytes, &pio.WriteBytes, &pio.CancelledWriteBytes)

        return pio, err
}