agola/internal/objectstorage/posix.go
Simone Gotti 34cfdfeb3b objectstorage: add size option to WriteObject
On s3 limit the max object size to 1GiB when the size is not provided (-1) or
the minio client will calculate a big part size since it tries to use the
maximum object size (5TiB) and will allocate a very big buffer in ram. Also
leave as commented out the previous hack that was firstly creating the file
locally to calculate the size and then put it (for future reference).
2019-05-02 09:47:38 +02:00

495 lines
10 KiB
Go

// Copyright 2019 Sorint.lab
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied
// See the License for the specific language governing permissions and
// limitations under the License.
package objectstorage
import (
"io"
"io/ioutil"
"os"
"path"
"path/filepath"
"strconv"
"strings"
"unicode/utf8"
"github.com/pkg/errors"
)
const (
dataDirName = "data"
tmpDirName = "tmp"
splitLength = 8
)
func shouldEscape(c rune) bool {
return c == '/' || c == '%'
}
// escape does percent encoding to '/' and adds a slash every 8 (of the original
// string) chars
func escape(s string) string {
sepCount, hexCount := 0, 0
nc := 0
for _, c := range s {
nc++
if shouldEscape(c) {
hexCount++
}
if nc%splitLength == 0 {
sepCount++
}
}
if sepCount == 0 && hexCount == 0 {
return s
}
hasFileMarker := nc%splitLength == 0
l := len(s) + sepCount + 2*hexCount
// if the string length is a multiple of 8 then we have to add a file marker
// ".f" to not ovverride a possible directory in our fs representation
if hasFileMarker {
l++
}
t := make([]byte, l)
j := 0
nc = 0
for _, c := range s {
nc++
switch {
case shouldEscape(c):
t[j] = '%'
t[j+1] = "0123456789ABCDEF"[c>>4]
t[j+2] = "0123456789ABCDEF"[c&15]
j += 3
default:
s := string(c)
for i := 0; i < len(s); i++ {
t[j] = s[i]
j++
}
}
if nc%splitLength == 0 {
t[j] = '/'
j++
}
}
// add file marker
if hasFileMarker {
t[j-1] = '.'
t[j] = 'f'
}
return string(t)
}
func ishex(c byte) bool {
switch {
case '0' <= c && c <= '9':
return true
case 'a' <= c && c <= 'f':
return true
case 'A' <= c && c <= 'F':
return true
}
return false
}
func unhex(c byte) byte {
switch {
case '0' <= c && c <= '9':
return c - '0'
case 'a' <= c && c <= 'f':
return c - 'a' + 10
case 'A' <= c && c <= 'F':
return c - 'A' + 10
}
return 0
}
type EscapeError string
func (e EscapeError) Error() string {
return "invalid URL escape " + strconv.Quote(string(e))
}
func unescape(s string) (string, bool, error) {
// number of percent encoded
n := 0
// number of slashes
ns := 0
// number of char in the unescaped string
nc := 0
for i := 0; i < len(s); {
r, width := utf8.DecodeRuneInString(s[i:])
if r == utf8.RuneError {
return "", false, errors.Errorf("bad UTF-8 string")
}
switch r {
case '%':
n++
if i+2 >= len(s) || !ishex(s[i+1]) || !ishex(s[i+2]) {
s = s[i:]
if len(s) > 3 {
s = s[:3]
}
return "", false, EscapeError(s)
}
i += 3
nc++
case '/':
ns++
if nc%splitLength != 0 {
return "", false, EscapeError(s)
}
i++
default:
i += width
nc++
}
}
// check and remove trailing file marker
hasFileMarker := false
if nc > splitLength && nc%splitLength == 2 && s[len(s)-2:] == ".f" {
hasFileMarker = true
s = s[:len(s)-2]
nc -= 2
}
if n == 0 && ns == 0 {
return s, hasFileMarker, nil
}
// destination string is
// the length of the escaped one (with the ending file marker already removed) - number of percent * 2 - number os slashes
t := make([]byte, len(s)-n*2-ns)
j := 0
for i := 0; i < len(s); {
r, width := utf8.DecodeRuneInString(s[i:])
if r == utf8.RuneError {
return "", false, errors.Errorf("bad UTF-8 string")
}
switch r {
case '%':
t[j] = unhex(s[i+1])<<4 | unhex(s[i+2])
j++
i += 3
case '/':
// skip "/"
i++
default:
for k := 0; k < width; k++ {
t[j] = s[i]
j++
i++
}
}
}
return string(t), hasFileMarker, nil
}
type PosixStorage struct {
dataDir string
tmpDir string
}
func NewPosixStorage(baseDir string) (*PosixStorage, error) {
if err := os.MkdirAll(baseDir, 0770); err != nil {
return nil, err
}
dataDir := filepath.Join(baseDir, dataDirName)
tmpDir := filepath.Join(baseDir, tmpDirName)
if err := os.MkdirAll(dataDir, 0770); err != nil {
return nil, errors.Wrapf(err, "failed to create data dir")
}
if err := os.MkdirAll(tmpDir, 0770); err != nil {
return nil, errors.Wrapf(err, "failed to create tmp dir")
}
return &PosixStorage{
dataDir: dataDir,
tmpDir: tmpDir,
}, nil
}
func (s *PosixStorage) fsPath(p string) (string, error) {
if p == "" {
return "", errors.Errorf("empty key name")
}
return filepath.Join(s.dataDir, escape(p)), nil
}
func (s *PosixStorage) Stat(p string) (*ObjectInfo, error) {
fspath, err := s.fsPath(p)
if err != nil {
return nil, err
}
fi, err := os.Stat(fspath)
if err != nil {
if os.IsNotExist(err) {
return nil, ErrNotExist
}
return nil, err
}
return &ObjectInfo{Path: p, LastModified: fi.ModTime()}, nil
}
func (s *PosixStorage) ReadObject(p string) (ReadSeekCloser, error) {
fspath, err := s.fsPath(p)
if err != nil {
return nil, err
}
f, err := os.Open(fspath)
if err != nil && os.IsNotExist(err) {
return nil, ErrNotExist
}
return f, err
}
func (s *PosixStorage) WriteObject(p string, data io.Reader, size int64, persist bool) error {
fspath, err := s.fsPath(p)
if err != nil {
return err
}
if err := os.MkdirAll(path.Dir(fspath), 0770); err != nil {
return err
}
return s.WriteFileAtomicFunc(fspath, 0660, persist, func(f io.Writer) error {
_, err := io.Copy(f, data)
return err
})
}
func (s *PosixStorage) DeleteObject(p string) error {
fspath, err := s.fsPath(p)
if err != nil {
return err
}
if err := os.Remove(fspath); err != nil {
if os.IsNotExist(err) {
return ErrNotExist
}
return err
}
// try to remove parent empty dirs
// TODO(sgotti) if this fails we ignore errors and the dirs will be left as
// empty, clean them asynchronously
pdir := filepath.Dir(fspath)
for {
if pdir == s.dataDir || !strings.HasPrefix(pdir, s.dataDir) {
break
}
f, err := os.Open(pdir)
if err != nil {
return nil
}
_, err = f.Readdirnames(1)
if err == io.EOF {
f.Close()
if err := os.Remove(pdir); err != nil {
return nil
}
} else {
f.Close()
break
}
pdir = filepath.Dir(pdir)
}
return nil
}
func (s *PosixStorage) List(prefix, startWith, delimiter string, doneCh <-chan struct{}) <-chan ObjectInfo {
objectCh := make(chan ObjectInfo, 1)
if len(delimiter) > 1 {
objectCh <- ObjectInfo{Err: errors.Errorf("wrong delimiter %q", delimiter)}
return objectCh
}
if startWith != "" && !strings.Contains(startWith, prefix) {
objectCh <- ObjectInfo{Err: errors.Errorf("wrong startwith value %q for prefix %q", startWith, prefix)}
return objectCh
}
recursive := delimiter == ""
// remove leading slash from prefix
if strings.HasPrefix(prefix, "/") {
prefix = strings.TrimPrefix(prefix, "/")
}
fprefix := filepath.Join(s.dataDir, escape(prefix))
root := filepath.Dir(fprefix)
if len(root) < len(s.dataDir) {
root = s.dataDir
}
// remove leading slash
if strings.HasPrefix(startWith, "/") {
startWith = strings.TrimPrefix(startWith, "/")
}
go func(objectCh chan<- ObjectInfo) {
var prevp string
defer close(objectCh)
err := filepath.Walk(root, func(ep string, info os.FileInfo, err error) error {
if err != nil && !os.IsNotExist(err) {
return err
}
if os.IsNotExist(err) {
return nil
}
p := ep
// get the path with / separator
p = filepath.ToSlash(p)
p, err = filepath.Rel(s.dataDir, p)
if err != nil {
return err
}
p, _, err = unescape(p)
if err != nil {
return err
}
if !recursive && len(p) > len(prefix) {
rel := strings.TrimPrefix(p, prefix)
skip := strings.Contains(rel, delimiter)
if info.IsDir() && skip {
return filepath.SkipDir
}
if skip {
return nil
}
}
// don't list dirs if there's not a file with the same name (with filemarker)
// it's not an issue if the file in the meantime has been removed, it won't
// just be listed
hasFile := true
_, err = os.Stat(ep + ".f")
if err != nil && !os.IsNotExist(err) {
return err
}
if os.IsNotExist(err) {
hasFile = false
}
if info.IsDir() && !hasFile {
return nil
}
if strings.HasPrefix(p, prefix) && p > startWith {
// skip keys smaller than the previously returned one. This happens when we
// receive a file with a file marker that we already returned previously
// when we received a dir with the same name
// it'not an issue if the dir has been removed since we already returned the file
if p > prevp {
select {
// Send object content.
case objectCh <- ObjectInfo{Path: p, LastModified: info.ModTime()}:
// If receives done from the caller, return here.
case <-doneCh:
return io.EOF
}
}
prevp = p
}
return nil
})
if err != nil && err != io.EOF {
objectCh <- ObjectInfo{
Err: err,
}
return
}
}(objectCh)
return objectCh
}
// WriteFileAtomicFunc atomically writes a file, it achieves this by creating a
// temporary file and then moving it. writeFunc is the func that will write
// data to the file.
// TODO(sgotti) remove left over tmp files if process crashes before calling
// os.Remove
func (s *PosixStorage) WriteFileAtomicFunc(p string, perm os.FileMode, persist bool, writeFunc func(f io.Writer) error) error {
f, err := ioutil.TempFile(s.tmpDir, "tmpfile")
if err != nil {
return err
}
err = writeFunc(f)
if persist && err == nil {
err = f.Sync()
}
if closeErr := f.Close(); err == nil {
err = closeErr
}
if permErr := os.Chmod(f.Name(), perm); err == nil {
err = permErr
}
if err == nil {
err = os.Rename(f.Name(), p)
}
if err != nil {
os.Remove(f.Name())
return err
}
if !persist {
return nil
}
// sync parent dirs
pdir := filepath.Dir(p)
for {
if !strings.HasPrefix(pdir, s.dataDir) {
break
}
f, err := os.Open(pdir)
if err != nil {
f.Close()
return nil
}
if err := f.Sync(); err != nil {
f.Close()
return nil
}
f.Close()
pdir = filepath.Dir(pdir)
}
return nil
}
func (s *PosixStorage) WriteFileAtomic(filename string, perm os.FileMode, persist bool, data []byte) error {
return s.WriteFileAtomicFunc(filename, perm, persist,
func(f io.Writer) error {
_, err := f.Write(data)
return err
})
}