github.com/dougm/docker@v1.5.0/pkg/system/meminfo_linux.go (about)

     1  package system
     2  
     3  import (
     4  	"bufio"
     5  	"errors"
     6  	"io"
     7  	"os"
     8  	"strconv"
     9  	"strings"
    10  
    11  	"github.com/docker/docker/pkg/units"
    12  )
    13  
    14  var (
    15  	ErrMalformed = errors.New("malformed file")
    16  )
    17  
    18  // Retrieve memory statistics of the host system and parse them into a MemInfo
    19  // type.
    20  func ReadMemInfo() (*MemInfo, error) {
    21  	file, err := os.Open("/proc/meminfo")
    22  	if err != nil {
    23  		return nil, err
    24  	}
    25  	defer file.Close()
    26  	return parseMemInfo(file)
    27  }
    28  
    29  func parseMemInfo(reader io.Reader) (*MemInfo, error) {
    30  	meminfo := &MemInfo{}
    31  	scanner := bufio.NewScanner(reader)
    32  	for scanner.Scan() {
    33  		// Expected format: ["MemTotal:", "1234", "kB"]
    34  		parts := strings.Fields(scanner.Text())
    35  
    36  		// Sanity checks: Skip malformed entries.
    37  		if len(parts) < 3 || parts[2] != "kB" {
    38  			continue
    39  		}
    40  
    41  		// Convert to bytes.
    42  		size, err := strconv.Atoi(parts[1])
    43  		if err != nil {
    44  			continue
    45  		}
    46  		bytes := int64(size) * units.KiB
    47  
    48  		switch parts[0] {
    49  		case "MemTotal:":
    50  			meminfo.MemTotal = bytes
    51  		case "MemFree:":
    52  			meminfo.MemFree = bytes
    53  		case "SwapTotal:":
    54  			meminfo.SwapTotal = bytes
    55  		case "SwapFree:":
    56  			meminfo.SwapFree = bytes
    57  		}
    58  
    59  	}
    60  
    61  	// Handle errors that may have occurred during the reading of the file.
    62  	if err := scanner.Err(); err != nil {
    63  		return nil, err
    64  	}
    65  
    66  	return meminfo, nil
    67  }