github.com/ava-labs/subnet-evm@v0.6.4/accounts/keystore/file_cache.go (about)

     1  // (c) 2019-2020, 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 2017 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  package keystore
    28  
    29  import (
    30  	"os"
    31  	"path/filepath"
    32  	"strings"
    33  	"sync"
    34  	"time"
    35  
    36  	mapset "github.com/deckarep/golang-set/v2"
    37  	"github.com/ethereum/go-ethereum/log"
    38  )
    39  
    40  // fileCache is a cache of files seen during scan of keystore.
    41  type fileCache struct {
    42  	all     mapset.Set[string] // Set of all files from the keystore folder
    43  	lastMod time.Time          // Last time instance when a file was modified
    44  	mu      sync.Mutex
    45  }
    46  
    47  // scan performs a new scan on the given directory, compares against the already
    48  // cached filenames, and returns file sets: creates, deletes, updates.
    49  func (fc *fileCache) scan(keyDir string) (mapset.Set[string], mapset.Set[string], mapset.Set[string], error) {
    50  	t0 := time.Now()
    51  
    52  	// List all the files from the keystore folder
    53  	files, err := os.ReadDir(keyDir)
    54  	if err != nil {
    55  		return nil, nil, nil, err
    56  	}
    57  	t1 := time.Now()
    58  
    59  	fc.mu.Lock()
    60  	defer fc.mu.Unlock()
    61  
    62  	// Iterate all the files and gather their metadata
    63  	all := mapset.NewThreadUnsafeSet[string]()
    64  	mods := mapset.NewThreadUnsafeSet[string]()
    65  
    66  	var newLastMod time.Time
    67  	for _, fi := range files {
    68  		path := filepath.Join(keyDir, fi.Name())
    69  		// Skip any non-key files from the folder
    70  		if nonKeyFile(fi) {
    71  			log.Trace("Ignoring file on account scan", "path", path)
    72  			continue
    73  		}
    74  		// Gather the set of all and freshly modified files
    75  		all.Add(path)
    76  
    77  		info, err := fi.Info()
    78  		if err != nil {
    79  			return nil, nil, nil, err
    80  		}
    81  		modified := info.ModTime()
    82  		if modified.After(fc.lastMod) {
    83  			mods.Add(path)
    84  		}
    85  		if modified.After(newLastMod) {
    86  			newLastMod = modified
    87  		}
    88  	}
    89  	t2 := time.Now()
    90  
    91  	// Update the tracked files and return the three sets
    92  	deletes := fc.all.Difference(all)   // Deletes = previous - current
    93  	creates := all.Difference(fc.all)   // Creates = current - previous
    94  	updates := mods.Difference(creates) // Updates = modified - creates
    95  
    96  	fc.all, fc.lastMod = all, newLastMod
    97  	t3 := time.Now()
    98  
    99  	// Report on the scanning stats and return
   100  	log.Debug("FS scan times", "list", t1.Sub(t0), "set", t2.Sub(t1), "diff", t3.Sub(t2))
   101  	return creates, deletes, updates, nil
   102  }
   103  
   104  // nonKeyFile ignores editor backups, hidden files and folders/symlinks.
   105  func nonKeyFile(fi os.DirEntry) bool {
   106  	// Skip editor backups and UNIX-style hidden files.
   107  	if strings.HasSuffix(fi.Name(), "~") || strings.HasPrefix(fi.Name(), ".") {
   108  		return true
   109  	}
   110  	// Skip misc special files, directories (yes, symlinks too).
   111  	if fi.IsDir() || !fi.Type().IsRegular() {
   112  		return true
   113  	}
   114  	return false
   115  }