github.com/arieschain/arieschain@v0.0.0-20191023063405-37c074544356/accounts/keystore/file_cache.go (about)

     1  package keystore
     2  
     3  import (
     4  	"io/ioutil"
     5  	"os"
     6  	"path/filepath"
     7  	"strings"
     8  	"sync"
     9  	"time"
    10  
    11  	"github.com/quickchainproject/quickchain/log"
    12  	set "gopkg.in/fatih/set.v0"
    13  )
    14  
    15  // fileCache is a cache of files seen during scan of keystore.
    16  type fileCache struct {
    17  	all     *set.SetNonTS // Set of all files from the keystore folder
    18  	lastMod time.Time     // Last time instance when a file was modified
    19  	mu      sync.RWMutex
    20  }
    21  
    22  // scan performs a new scan on the given directory, compares against the already
    23  // cached filenames, and returns file sets: creates, deletes, updates.
    24  func (fc *fileCache) scan(keyDir string) (set.Interface, set.Interface, set.Interface, error) {
    25  	t0 := time.Now()
    26  
    27  	// List all the failes from the keystore folder
    28  	files, err := ioutil.ReadDir(keyDir)
    29  	if err != nil {
    30  		return nil, nil, nil, err
    31  	}
    32  	t1 := time.Now()
    33  
    34  	fc.mu.Lock()
    35  	defer fc.mu.Unlock()
    36  
    37  	// Iterate all the files and gather their metadata
    38  	all := set.NewNonTS()
    39  	mods := set.NewNonTS()
    40  
    41  	var newLastMod time.Time
    42  	for _, fi := range files {
    43  		// Skip any non-key files from the folder
    44  		path := filepath.Join(keyDir, fi.Name())
    45  		if skipKeyFile(fi) {
    46  			log.Trace("Ignoring file on account scan", "path", path)
    47  			continue
    48  		}
    49  		// Gather the set of all and fresly modified files
    50  		all.Add(path)
    51  
    52  		modified := fi.ModTime()
    53  		if modified.After(fc.lastMod) {
    54  			mods.Add(path)
    55  		}
    56  		if modified.After(newLastMod) {
    57  			newLastMod = modified
    58  		}
    59  	}
    60  	t2 := time.Now()
    61  
    62  	// Update the tracked files and return the three sets
    63  	deletes := set.Difference(fc.all, all)   // Deletes = previous - current
    64  	creates := set.Difference(all, fc.all)   // Creates = current - previous
    65  	updates := set.Difference(mods, creates) // Updates = modified - creates
    66  
    67  	fc.all, fc.lastMod = all, newLastMod
    68  	t3 := time.Now()
    69  
    70  	// Report on the scanning stats and return
    71  	log.Debug("FS scan times", "list", t1.Sub(t0), "set", t2.Sub(t1), "diff", t3.Sub(t2))
    72  	return creates, deletes, updates, nil
    73  }
    74  
    75  // skipKeyFile ignores editor backups, hidden files and folders/symlinks.
    76  func skipKeyFile(fi os.FileInfo) bool {
    77  	// Skip editor backups and UNIX-style hidden files.
    78  	if strings.HasSuffix(fi.Name(), "~") || strings.HasPrefix(fi.Name(), ".") {
    79  		return true
    80  	}
    81  	// Skip misc special files, directories (yes, symlinks too).
    82  	if fi.IsDir() || fi.Mode()&os.ModeType != 0 {
    83  		return true
    84  	}
    85  	return false
    86  }