Significant CPU and syscall performance improvements when iterating large directories

This commit is contained in:
Dane Everitt 2020-08-24 20:45:54 -07:00
parent f82c91afbe
commit a1288565f0
No known key found for this signature in database
GPG Key ID: EEA66103B3D71F53
6 changed files with 142 additions and 240 deletions

1
go.mod
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@ -47,6 +47,7 @@ require (
github.com/iancoleman/strcase v0.0.0-20191112232945-16388991a334
github.com/icza/dyno v0.0.0-20200205103839-49cb13720835
github.com/imdario/mergo v0.3.8
github.com/karrick/godirwalk v1.16.1
github.com/klauspost/compress v1.10.10 // indirect
github.com/klauspost/pgzip v1.2.4
github.com/magefile/mage v1.10.0 // indirect

2
go.sum
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@ -317,6 +317,8 @@ github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfV
github.com/julienschmidt/httprouter v1.2.0 h1:TDTW5Yz1mjftljbcKqRcrYhd4XeOoI98t+9HbQbYf7g=
github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
github.com/karrick/godirwalk v1.16.1 h1:DynhcF+bztK8gooS0+NDJFrdNZjJ3gzVzC545UNA9iw=
github.com/karrick/godirwalk v1.16.1/go.mod h1:j4mkqPuvaLI8mp1DroR3P6ad7cyYd4c1qeJ3RV7ULlk=
github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51 h1:Z9n2FFNUXsshfwJMBgNA0RU6/i7WVaAegv3PtuIHPMs=
github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51/go.mod h1:CzGEWj7cYgsdH8dAjBGEr58BoE7ScuLd+fwFZ44+/x8=
github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=

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@ -5,6 +5,7 @@ import (
"context"
"github.com/apex/log"
gzip "github.com/klauspost/pgzip"
"github.com/pkg/errors"
"github.com/remeh/sizedwaitgroup"
"golang.org/x/sync/errgroup"
"io"
@ -49,14 +50,8 @@ func (a *Archive) Create(dst string, ctx context.Context) (os.FileInfo, error) {
// Iterate over all of the files to be included and put them into the archive. This is
// done as a concurrent goroutine to speed things along. If an error is encountered at
// any step, the entire process is aborted.
for p, s := range a.Files.All() {
if (*s).IsDir() {
continue
}
pa := p
st := s
for _, p := range a.Files.All() {
p := p
g.Go(func() error {
wg.Add()
defer wg.Done()
@ -65,7 +60,7 @@ func (a *Archive) Create(dst string, ctx context.Context) (os.FileInfo, error) {
case <-ctx.Done():
return ctx.Err()
default:
return a.addToArchive(pa, st, tw)
return a.addToArchive(p, tw)
}
})
}
@ -92,21 +87,25 @@ func (a *Archive) Create(dst string, ctx context.Context) (os.FileInfo, error) {
}
// Adds a single file to the existing tar archive writer.
func (a *Archive) addToArchive(p string, s *os.FileInfo, w *tar.Writer) error {
func (a *Archive) addToArchive(p string, w *tar.Writer) error {
f, err := os.Open(p)
if err != nil {
return err
}
defer f.Close()
st := *s
s, err := f.Stat()
if err != nil {
return errors.WithStack(err)
}
header := &tar.Header{
// Trim the long server path from the name of the file so that the resulting
// archive is exactly how the user would see it in the panel file manager.
Name: strings.TrimPrefix(p, a.TrimPrefix),
Size: st.Size(),
Mode: int64(st.Mode()),
ModTime: st.ModTime(),
Size: s.Size(),
Mode: int64(s.Mode()),
ModTime: s.ModTime(),
}
// These actions must occur sequentially, even if this function is called multiple

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@ -1,29 +1,23 @@
package backup
import (
"os"
"sync"
)
type IncludedFiles struct {
sync.RWMutex
files map[string]*os.FileInfo
files []string
}
// Pushes an additional file or folder onto the struct.
func (i *IncludedFiles) Push(info *os.FileInfo, p string) {
func (i *IncludedFiles) Push(p string) {
i.Lock()
defer i.Unlock()
if i.files == nil {
i.files = make(map[string]*os.FileInfo)
}
i.files[p] = info
i.files = append(i.files, p) // ~~
i.Unlock()
}
// Returns all of the files that were marked as being included.
func (i *IncludedFiles) All() map[string]*os.FileInfo {
func (i *IncludedFiles) All() []string {
i.RLock()
defer i.RUnlock()

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@ -6,6 +6,7 @@ import (
"encoding/json"
"fmt"
"github.com/gabriel-vasile/mimetype"
"github.com/karrick/godirwalk"
"github.com/pkg/errors"
"github.com/pterodactyl/wings/config"
"github.com/pterodactyl/wings/server/backup"
@ -21,6 +22,7 @@ import (
"strings"
"sync"
"sync/atomic"
"syscall"
"time"
)
@ -210,29 +212,33 @@ func (fs *Filesystem) ParallelSafePath(paths []string) ([]string, error) {
// Because determining the amount of space being used by a server is a taxing operation we
// will load it all up into a cache and pull from that as long as the key is not expired.
func (fs *Filesystem) HasSpaceAvailable() bool {
space := fs.Server.Build().DiskSpace
size, err := fs.getCachedDiskUsage()
if err != nil {
fs.Server.Log().WithField("error", err).Warn("failed to determine root server directory size")
}
// Determine if their folder size, in bytes, is smaller than the amount of space they've
// been allocated.
fs.Server.Proc().SetDisk(size)
// If space is -1 or 0 just return true, means they're allowed unlimited.
//
// Technically we could skip disk space calculation because we don't need to check if the server exceeds it's limit
// but because this method caches the disk usage it would be best to calculate the disk usage and always
// return true.
if space <= 0 {
return true
}
return (size / 1000.0 / 1000.0) <= space
}
// func (fs *Filesystem) HasSpaceAvailable() bool {
// space := fs.Server.Build().DiskSpace
//
// size, err := fs.getCachedDiskUsage()
// if err != nil {
// fs.Server.Log().WithField("error", err).Warn("failed to determine root server directory size")
// }
//
// // Determine if their folder size, in bytes, is smaller than the amount of space they've
// // been allocated.
// fs.Server.Proc().SetDisk(size)
//
// // If space is -1 or 0 just return true, means they're allowed unlimited.
// //
// // Technically we could skip disk space calculation because we don't need to check if the server exceeds it's limit
// // but because this method caches the disk usage it would be best to calculate the disk usage and always
// // return true.
// if space <= 0 {
// return true
// }
//
// return (size / 1000.0 / 1000.0) <= space
// }
// Internal helper function to allow other parts of the codebase to check the total used disk space
// as needed without overly taxing the system. This will prioritize the value from the cache to avoid
// excessive IO usage. We will only walk the filesystem and determine the size of the directory if there
@ -270,20 +276,40 @@ func (fs *Filesystem) getCachedDiskUsage() (int64, error) {
// through all of the folders. Returns the size in bytes. This can be a fairly taxing operation
// on locations with tons of files, so it is recommended that you cache the output.
func (fs *Filesystem) DirectorySize(dir string) (int64, error) {
var size int64
err := fs.Walk(dir, func(_ string, f os.FileInfo, err error) error {
d, err := fs.SafePath(dir)
if err != nil {
return fs.handleWalkerError(err, f)
return 0, errors.WithStack(err)
}
if !f.IsDir() {
atomic.AddInt64(&size, f.Size())
var size int64
var st syscall.Stat_t
err = godirwalk.Walk(d, &godirwalk.Options{
Unsorted: true,
Callback: func(p string, e *godirwalk.Dirent) error {
// If this is a symlink then resolve the final destination of it before trying to continue walking
// over its contents. If it resolves outside the server data directory just skip everything else for
// it. Otherwise, allow it to continue.
if e.IsSymlink() {
if _, err := fs.SafePath(p); err != nil {
if IsPathResolutionError(err) {
return godirwalk.SkipThis
}
return err
}
}
if !e.IsDir() {
syscall.Lstat(p, &st)
atomic.AddInt64(&size, st.Size)
}
return nil
},
})
return size, err
return size, errors.WithStack(err)
}
// Reads a file on the system and returns it as a byte representation in a file
@ -485,19 +511,22 @@ func (fs *Filesystem) Chown(path string) error {
// If this was a directory, begin walking over its contents recursively and ensure that all
// of the subfiles and directories get their permissions updated as well.
return fs.Walk(cleaned, func(path string, f os.FileInfo, err error) error {
if err != nil {
return fs.handleWalkerError(err, f)
}
return godirwalk.Walk(cleaned, &godirwalk.Options{
Unsorted: true,
Callback: func(p string, e *godirwalk.Dirent) error {
// Do not attempt to chmod a symlink. Go's os.Chown function will affect the symlink
// so if it points to a location outside the data directory the user would be able to
// (un)intentionally modify that files permissions.
if f.Mode()&os.ModeSymlink != 0 {
if e.IsSymlink() {
if e.IsDir() {
return godirwalk.SkipThis
}
return nil
}
return os.Chown(path, uid, gid)
return os.Chown(p, uid, gid)
},
})
}
@ -733,26 +762,35 @@ func (fs *Filesystem) GetIncludedFiles(dir string, ignored []string) (*backup.In
// files found, and will keep walking deeper and deeper into directories.
inc := new(backup.IncludedFiles)
if err := fs.Walk(cleaned, func(p string, f os.FileInfo, err error) error {
err = godirwalk.Walk(cleaned, &godirwalk.Options{
Unsorted: true,
Callback: func(p string, e *godirwalk.Dirent) error {
sp := p
if e.IsSymlink() {
sp, err = fs.SafePath(p)
if err != nil {
return fs.handleWalkerError(err, f)
if IsPathResolutionError(err) {
return godirwalk.SkipThis
}
return err
}
}
// Avoid unnecessary parsing if there are no ignored files, nothing will match anyways
// so no reason to call the function.
if len(ignored) == 0 || !i.MatchesPath(strings.TrimPrefix(p, fs.Path()+"/")) {
inc.Push(&f, p)
if len(ignored) == 0 || !i.MatchesPath(strings.TrimPrefix(sp, fs.Path()+"/")) {
inc.Push(sp)
}
// We can't just abort if the path is technically ignored. It is possible there is a nested
// file or folder that should not be excluded, so in this case we need to just keep going
// until we get to a final state.
return nil
}); err != nil {
return nil, err
}
},
})
return inc, nil
return inc, errors.WithStack(err)
}
// Compresses all of the files matching the given paths in the specified directory. This function
@ -789,24 +827,38 @@ func (fs *Filesystem) CompressFiles(dir string, paths []string) (os.FileInfo, er
continue
}
if f.IsDir() {
err := fs.Walk(p, func(s string, info os.FileInfo, err error) error {
if !f.IsDir() {
inc.Push(p)
} else {
err := godirwalk.Walk(p, &godirwalk.Options{
Unsorted: true,
Callback: func(p string, e *godirwalk.Dirent) error {
sp := p
if e.IsSymlink() {
// Ensure that any symlinks are properly resolved to their final destination. If
// that destination is outside the server directory skip over this entire item, otherwise
// use the resolved location for the rest of this function.
sp, err = fs.SafePath(p)
if err != nil {
return fs.handleWalkerError(err, info)
if IsPathResolutionError(err) {
return godirwalk.SkipThis
}
if !info.IsDir() {
inc.Push(&info, s)
return err
}
}
if !e.IsDir() {
inc.Push(sp)
}
return nil
},
})
if err != nil {
return nil, err
}
} else {
inc.Push(&f, p)
}
}

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@ -1,146 +0,0 @@
package server
import (
"context"
"github.com/gammazero/workerpool"
"github.com/pkg/errors"
"io/ioutil"
"os"
"path/filepath"
"sync"
)
type FileWalker struct {
*Filesystem
}
type PooledFileWalker struct {
wg sync.WaitGroup
pool *workerpool.WorkerPool
callback filepath.WalkFunc
cancel context.CancelFunc
err error
errOnce sync.Once
Filesystem *Filesystem
}
// Returns a new walker instance.
func (fs *Filesystem) NewWalker() *FileWalker {
return &FileWalker{fs}
}
// Creates a new pooled file walker that will concurrently walk over a given directory but limit itself
// to a worker pool as to not completely flood out the system or cause a process crash.
func newPooledWalker(fs *Filesystem) *PooledFileWalker {
return &PooledFileWalker{
Filesystem: fs,
// Run the walker as a single threaded process to optimize disk I/O and avoid CPU issues.
pool: workerpool.New(1),
}
}
// Process a given path by calling the callback function for all of the files and directories within
// the path, and then dropping into any directories that we come across.
func (w *PooledFileWalker) process(p string) error {
files, err := ioutil.ReadDir(p)
if err != nil {
return err
}
// Loop over all of the files and directories in the given directory and call the provided
// callback function. If we encounter a directory, push that directory onto the worker queue
// to be processed.
for _, f := range files {
sp, err := w.Filesystem.SafeJoin(p, f)
if err != nil {
// Let the callback function handle what to do if there is a path resolution error because a
// dangerous path was resolved. If there is an error returned, return from this entire process
// otherwise just skip over this specific file. We don't care if its a file or a directory at
// this point since either way we're skipping it, however, still check for the SkipDir since that
// would be thrown otherwise.
if err = w.callback(sp, f, err); err != nil && err != filepath.SkipDir {
return err
}
continue
}
var i os.FileInfo
// Re-stat the file or directory if it is determined to be a symlink by statting the result of the
// symlink resolution rather than the initial path we received. Only do this on files we _know_
// will be returning a different value.
if f.Mode()&os.ModeSymlink != 0 {
i, err = os.Stat(sp)
// You might end up getting an error about a file or folder not existing if the given path
// if it is an invalid symlink. We can safely just skip over these files I believe.
if os.IsNotExist(err) {
continue
}
} else {
i = f
}
// Call the user-provided callback for this file or directory. If an error is returned that is
// not a SkipDir call, abort the entire process and bubble that error up.
if err = w.callback(sp, i, err); err != nil && err != filepath.SkipDir {
return err
}
// If this is a directory, and we didn't get a SkipDir error, continue through by pushing another
// job to the pool to handle it. If we requested a skip, don't do anything just continue on to the
// next item.
if i.IsDir() && err != filepath.SkipDir {
w.push(sp)
} else if !i.IsDir() && err == filepath.SkipDir {
// Per the spec for the callback, if we get a SkipDir error but it is returned for an item
// that is _not_ a directory, abort the remaining operations on the directory.
return nil
}
}
return nil
}
// Push a new path into the worker pool and increment the waitgroup so that we do not return too
// early and cause panic's as internal directories attempt to submit to the pool.
func (w *PooledFileWalker) push(path string) {
w.wg.Add(1)
w.pool.Submit(func() {
defer w.wg.Done()
if err := w.process(path); err != nil {
w.errOnce.Do(func() {
w.err = err
if w.cancel != nil {
w.cancel()
}
})
}
})
}
// Walks the given directory and executes the callback function for all of the files and directories
// that are encountered.
func (fs *Filesystem) Walk(dir string, callback filepath.WalkFunc) error {
w := newPooledWalker(fs)
w.callback = callback
_, cancel := context.WithCancel(context.Background())
w.cancel = cancel
p, err := w.Filesystem.SafePath(dir)
if err != nil {
return errors.WithStack(err)
}
w.push(p)
w.wg.Wait()
w.pool.StopWait()
if w.err != nil {
return w.err
}
return nil
}