libs/common: Refactor tempfile code into its own file
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@ -8,7 +8,6 @@ import (
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"os"
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"os/exec"
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"os/signal"
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"path/filepath"
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"strings"
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"syscall"
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)
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@ -124,60 +123,6 @@ func MustWriteFile(filePath string, contents []byte, mode os.FileMode) {
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}
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}
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// WriteFileAtomic creates a temporary file with data and the perm given and
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// swaps it atomically with filename if successful.
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func WriteFileAtomic(filename string, data []byte, perm os.FileMode) error {
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var (
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dir = filepath.Dir(filename)
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tempFile = filepath.Join(dir, "write-file-atomic-"+RandStr(32))
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// Override in case it does exist, create in case it doesn't and force kernel
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// flush, which still leaves the potential of lingering disk cache.
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flag = os.O_WRONLY | os.O_CREATE | os.O_SYNC | os.O_TRUNC
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)
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f, err := os.OpenFile(tempFile, flag, perm)
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if err != nil {
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return err
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}
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// Clean up in any case. Defer stacking order is last-in-first-out.
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defer os.Remove(f.Name())
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defer f.Close()
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if n, err := f.Write(data); err != nil {
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return err
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} else if n < len(data) {
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return io.ErrShortWrite
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}
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// Close the file before renaming it, otherwise it will cause "The process
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// cannot access the file because it is being used by another process." on windows.
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f.Close()
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return os.Rename(f.Name(), filename)
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}
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//--------------------------------------------------------------------------------
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func Tempfile(prefix string) (*os.File, string) {
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file, err := ioutil.TempFile("", prefix)
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if err != nil {
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PanicCrisis(err)
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}
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return file, file.Name()
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}
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func Tempdir(prefix string) (*os.File, string) {
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tempDir := os.TempDir() + "/" + prefix + RandStr(12)
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err := EnsureDir(tempDir, 0700)
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if err != nil {
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panic(Fmt("Error creating temp dir: %v", err))
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}
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dir, err := os.Open(tempDir)
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if err != nil {
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panic(Fmt("Error opening temp dir: %v", err))
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}
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return dir, tempDir
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}
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//--------------------------------------------------------------------------------
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func Prompt(prompt string, defaultValue string) (string, error) {
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@ -0,0 +1,63 @@
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package common
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import (
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"io"
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"io/ioutil"
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"os"
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"path/filepath"
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)
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// WriteFileAtomic creates a temporary file with data and the perm given and
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// swaps it atomically with filename if successful.
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func WriteFileAtomic(filename string, data []byte, perm os.FileMode) error {
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var (
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dir = filepath.Dir(filename)
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// Create in case it doesn't exist and force kernel
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// flush, which still leaves the potential of lingering disk cache.
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// Never overwrites files
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flag = os.O_WRONLY | os.O_CREATE | os.O_SYNC | os.O_TRUNC | os.O_EXCL
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)
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tempFile := filepath.Join(dir, "write-file-atomic-"+RandStr(32))
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f, err := os.OpenFile(tempFile, flag, perm)
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if err != nil {
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return err
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}
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// Clean up in any case. Defer stacking order is last-in-first-out.
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defer os.Remove(f.Name())
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defer f.Close()
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if n, err := f.Write(data); err != nil {
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return err
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} else if n < len(data) {
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return io.ErrShortWrite
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}
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// Close the file before renaming it, otherwise it will cause "The process
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// cannot access the file because it is being used by another process." on windows.
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f.Close()
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return os.Rename(f.Name(), filename)
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}
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//--------------------------------------------------------------------------------
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func Tempfile(prefix string) (*os.File, string) {
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file, err := ioutil.TempFile("", prefix)
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if err != nil {
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PanicCrisis(err)
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}
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return file, file.Name()
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}
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func Tempdir(prefix string) (*os.File, string) {
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tempDir := os.TempDir() + "/" + prefix + RandStr(12)
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err := EnsureDir(tempDir, 0700)
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if err != nil {
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panic(Fmt("Error creating temp dir: %v", err))
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}
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dir, err := os.Open(tempDir)
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if err != nil {
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panic(Fmt("Error opening temp dir: %v", err))
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}
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return dir, tempDir
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}
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