github.com/lzy4123/fabric@v2.1.1+incompatible/common/ledger/util/ioutil.go (about)

     1  /*
     2  Copyright IBM Corp. All Rights Reserved.
     3  
     4  SPDX-License-Identifier: Apache-2.0
     5  */
     6  
     7  package util
     8  
     9  import (
    10  	"io"
    11  	"io/ioutil"
    12  	"os"
    13  	"path"
    14  	"strings"
    15  
    16  	"github.com/hyperledger/fabric/common/flogging"
    17  	"github.com/pkg/errors"
    18  )
    19  
    20  var logger = flogging.MustGetLogger("kvledger.util")
    21  
    22  // CreateDirIfMissing creates a dir for dirPath if not already exists. If the dir is empty it returns true
    23  func CreateDirIfMissing(dirPath string) (bool, error) {
    24  	// if dirPath does not end with a path separator, it leaves out the last segment while creating directories
    25  	if !strings.HasSuffix(dirPath, "/") {
    26  		dirPath = dirPath + "/"
    27  	}
    28  	logger.Debugf("CreateDirIfMissing [%s]", dirPath)
    29  	logDirStatus("Before creating dir", dirPath)
    30  	err := os.MkdirAll(path.Dir(dirPath), 0755)
    31  	if err != nil {
    32  		logger.Debugf("Error creating dir [%s]", dirPath)
    33  		return false, errors.Wrapf(err, "error creating dir [%s]", dirPath)
    34  	}
    35  	logDirStatus("After creating dir", dirPath)
    36  	return DirEmpty(dirPath)
    37  }
    38  
    39  // DirEmpty returns true if the dir at dirPath is empty
    40  func DirEmpty(dirPath string) (bool, error) {
    41  	f, err := os.Open(dirPath)
    42  	if err != nil {
    43  		logger.Debugf("Error opening dir [%s]: %+v", dirPath, err)
    44  		return false, errors.Wrapf(err, "error opening dir [%s]", dirPath)
    45  	}
    46  	defer f.Close()
    47  
    48  	_, err = f.Readdir(1)
    49  	if err == io.EOF {
    50  		return true, nil
    51  	}
    52  	err = errors.Wrapf(err, "error checking if dir [%s] is empty", dirPath)
    53  	return false, err
    54  }
    55  
    56  // FileExists checks whether the given file exists.
    57  // If the file exists, this method also returns the size of the file.
    58  func FileExists(filePath string) (bool, int64, error) {
    59  	fileInfo, err := os.Stat(filePath)
    60  	if os.IsNotExist(err) {
    61  		return false, 0, nil
    62  	}
    63  	if err != nil {
    64  		return false, 0, errors.Wrapf(err, "error checking if file [%s] exists", filePath)
    65  	}
    66  	return true, fileInfo.Size(), nil
    67  }
    68  
    69  // ListSubdirs returns the subdirectories
    70  func ListSubdirs(dirPath string) ([]string, error) {
    71  	subdirs := []string{}
    72  	files, err := ioutil.ReadDir(dirPath)
    73  	if err != nil {
    74  		return nil, errors.Wrapf(err, "error reading dir %s", dirPath)
    75  	}
    76  	for _, f := range files {
    77  		if f.IsDir() {
    78  			subdirs = append(subdirs, f.Name())
    79  		}
    80  	}
    81  	return subdirs, nil
    82  }
    83  
    84  func logDirStatus(msg string, dirPath string) {
    85  	exists, _, err := FileExists(dirPath)
    86  	if err != nil {
    87  		logger.Errorf("Error checking for dir existence")
    88  	}
    89  	if exists {
    90  		logger.Debugf("%s - [%s] exists", msg, dirPath)
    91  	} else {
    92  		logger.Debugf("%s - [%s] does not exist", msg, dirPath)
    93  	}
    94  }