github.com/kchristidis/fabric@v1.0.4-0.20171028114726-837acd08cde1/common/ledger/util/ioutil.go (about)

     1  /*
     2  Copyright IBM Corp. 2016 All Rights Reserved.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8  		 http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package util
    18  
    19  import (
    20  	"io"
    21  	"io/ioutil"
    22  	"os"
    23  	"path"
    24  	"strings"
    25  
    26  	"github.com/hyperledger/fabric/common/flogging"
    27  )
    28  
    29  var logger = flogging.MustGetLogger("kvledger.util")
    30  
    31  // CreateDirIfMissing creates a dir for dirPath if not already exists. If the dir is empty it returns true
    32  func CreateDirIfMissing(dirPath string) (bool, error) {
    33  	// if dirPath does not end with a path separator, it leaves out the last segment while creating directories
    34  	if !strings.HasSuffix(dirPath, "/") {
    35  		dirPath = dirPath + "/"
    36  	}
    37  	logger.Debugf("CreateDirIfMissing [%s]", dirPath)
    38  	logDirStatus("Before creating dir", dirPath)
    39  	err := os.MkdirAll(path.Dir(dirPath), 0755)
    40  	if err != nil {
    41  		logger.Debugf("Error while creating dir [%s]", dirPath)
    42  		return false, err
    43  	}
    44  	logDirStatus("After creating dir", dirPath)
    45  	return DirEmpty(dirPath)
    46  }
    47  
    48  // DirEmpty returns true if the dir at dirPath is empty
    49  func DirEmpty(dirPath string) (bool, error) {
    50  	f, err := os.Open(dirPath)
    51  	if err != nil {
    52  		logger.Debugf("Error while opening dir [%s]: %s", dirPath, err)
    53  		return false, err
    54  	}
    55  	defer f.Close()
    56  
    57  	_, err = f.Readdir(1)
    58  	if err == io.EOF {
    59  		return true, nil
    60  	}
    61  	return false, err
    62  }
    63  
    64  // FileExists checks whether the given file exists.
    65  // If the file exists, this method also returns the size of the file.
    66  func FileExists(filePath string) (bool, int64, error) {
    67  	fileInfo, err := os.Stat(filePath)
    68  	if os.IsNotExist(err) {
    69  		return false, 0, nil
    70  	}
    71  	return true, fileInfo.Size(), err
    72  }
    73  
    74  // ListSubdirs returns the subdirectories
    75  func ListSubdirs(dirPath string) ([]string, error) {
    76  	subdirs := []string{}
    77  	files, err := ioutil.ReadDir(dirPath)
    78  	if err != nil {
    79  		return nil, err
    80  	}
    81  	for _, f := range files {
    82  		if f.IsDir() {
    83  			subdirs = append(subdirs, f.Name())
    84  		}
    85  	}
    86  	return subdirs, nil
    87  }
    88  
    89  func logDirStatus(msg string, dirPath string) {
    90  	exists, _, err := FileExists(dirPath)
    91  	if err != nil {
    92  		logger.Errorf("Error while checking for dir existence")
    93  	}
    94  	if exists {
    95  		logger.Debugf("%s - [%s] exists", msg, dirPath)
    96  	} else {
    97  		logger.Debugf("%s - [%s] does not exist", msg, dirPath)
    98  	}
    99  }