github.com/ava-labs/subnet-evm@v0.6.4/metrics/disk_linux.go (about)

     1  // (c) 2022, Ava Labs, Inc.
     2  //
     3  // This file is a derived work, based on the go-ethereum library whose original
     4  // notices appear below.
     5  //
     6  // It is distributed under a license compatible with the licensing terms of the
     7  // original code from which it is derived.
     8  //
     9  // Much love to the original authors for their work.
    10  // **********
    11  // Copyright 2015 The go-ethereum Authors
    12  // This file is part of the go-ethereum library.
    13  //
    14  // The go-ethereum library is free software: you can redistribute it and/or modify
    15  // it under the terms of the GNU Lesser General Public License as published by
    16  // the Free Software Foundation, either version 3 of the License, or
    17  // (at your option) any later version.
    18  //
    19  // The go-ethereum library is distributed in the hope that it will be useful,
    20  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    21  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    22  // GNU Lesser General Public License for more details.
    23  //
    24  // You should have received a copy of the GNU Lesser General Public License
    25  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    26  
    27  // Contains the Linux implementation of process disk IO counter retrieval.
    28  
    29  package metrics
    30  
    31  import (
    32  	"bufio"
    33  	"fmt"
    34  	"io"
    35  	"os"
    36  	"strconv"
    37  	"strings"
    38  )
    39  
    40  // ReadDiskStats retrieves the disk IO stats belonging to the current process.
    41  func ReadDiskStats(stats *DiskStats) error {
    42  	// Open the process disk IO counter file
    43  	inf, err := os.Open(fmt.Sprintf("/proc/%d/io", os.Getpid()))
    44  	if err != nil {
    45  		return err
    46  	}
    47  	defer inf.Close()
    48  	in := bufio.NewReader(inf)
    49  
    50  	// Iterate over the IO counter, and extract what we need
    51  	for {
    52  		// Read the next line and split to key and value
    53  		line, err := in.ReadString('\n')
    54  		if err != nil {
    55  			if err == io.EOF {
    56  				return nil
    57  			}
    58  			return err
    59  		}
    60  		parts := strings.Split(line, ":")
    61  		if len(parts) != 2 {
    62  			continue
    63  		}
    64  		key := strings.TrimSpace(parts[0])
    65  		value, err := strconv.ParseInt(strings.TrimSpace(parts[1]), 10, 64)
    66  		if err != nil {
    67  			return err
    68  		}
    69  
    70  		// Update the counter based on the key
    71  		switch key {
    72  		case "syscr":
    73  			stats.ReadCount = value
    74  		case "syscw":
    75  			stats.WriteCount = value
    76  		case "rchar":
    77  			stats.ReadBytes = value
    78  		case "wchar":
    79  			stats.WriteBytes = value
    80  		}
    81  	}
    82  }