Split pretty huge gocheese.go

[gocheese.git] / fileutils.go

diff --git a/fileutils.go b/fileutils.go
new file mode 100644 (file)
index 0000000..70d3f11
--- /dev/null
+++ b/fileutils.go
@@ -0,0 +1,67 @@
+/*
+GoCheese -- Python private package repository and caching proxy
+Copyright (C) 2019 Sergey Matveev <stargrave@stargrave.org>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, version 3 of the License.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package main
+
+import (
+       "os"
+       "path/filepath"
+       "strconv"
+       "time"
+)
+
+func TempFile(dir string) (*os.File, error) {
+       // Assume that probability of suffix collision is negligible
+       suffix := strconv.FormatInt(time.Now().UnixNano()+int64(os.Getpid()), 16)
+       name := filepath.Join(dir, "nncp"+suffix)
+       return os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, os.FileMode(0666))
+}
+
+func DirSync(dirPath string) error {
+       fd, err := os.Open(dirPath)
+       if err != nil {
+               return err
+       }
+       err = fd.Sync()
+       if err != nil {
+               fd.Close()
+               return err
+       }
+       return fd.Close()
+}
+
+func WriteFileSync(dirPath, filePath string, data []byte) error {
+       dst, err := TempFile(dirPath)
+       if err != nil {
+               return err
+       }
+       if _, err = dst.Write(data); err != nil {
+               os.Remove(dst.Name())
+               dst.Close()
+               return err
+       }
+       if err = dst.Sync(); err != nil {
+               os.Remove(dst.Name())
+               dst.Close()
+               return err
+       }
+       dst.Close()
+       if err = os.Rename(dst.Name(), filePath); err != nil {
+               return err
+       }
+       return DirSync(dirPath)
+}