cache: OS-specific cache directories

Windows, and to a lesser extent OS X, don't conform to XDG and have
their own preferred locations for caches.

On Windows, use %LOCALAPPDATA%/restic (i.e., ~/AppData/Local/restic). I
can't find authoritative documentation from Microsoft recommending
specifically which of %APPDATA%, %LOCALAPPDATA%, and %TEMP% should be
used for caches, but %LOCALAPPDATA% is where browsers store their
caches, so it seems like a good fit.

On OS X, use ~/Library/Caches/restic, which is recommended by the Apple
documentation. They do suggest using the application "bundle identifier"
as the base folder name, but restic doesn't have one, so I just used
"restic".
This commit is contained in:
Michael Pratt 2017-09-27 21:16:22 -07:00
parent 1ee1559506
commit 2133869127
2 changed files with 51 additions and 10 deletions

View File

@ -84,7 +84,7 @@ func writeCachedirTag(dir string) error {
// performReadahead returns true.
func New(id string, basedir string) (c *Cache, err error) {
if basedir == "" {
basedir, err = getXDGCacheDir()
basedir, err = defaultCacheDir()
if err != nil {
return nil, err
}

59
internal/cache/dir.go vendored
View File

@ -3,27 +3,68 @@ package cache
import (
"os"
"path/filepath"
"runtime"
"github.com/pkg/errors"
"github.com/restic/restic/internal/debug"
"github.com/restic/restic/internal/fs"
)
// getXDGCacheDir returns the cache directory according to XDG basedir spec, see
// xdgCacheDir returns the cache directory according to XDG basedir spec, see
// http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
func getXDGCacheDir() (string, error) {
func xdgCacheDir() (string, error) {
xdgcache := os.Getenv("XDG_CACHE_HOME")
home := os.Getenv("HOME")
if xdgcache == "" && home == "" {
return "", errors.New("unable to locate cache directory (XDG_CACHE_HOME and HOME unset)")
if xdgcache != "" {
return filepath.Join(xdgcache, "restic"), nil
} else if home != "" {
return filepath.Join(home, ".cache", "restic"), nil
}
cachedir := ""
if xdgcache != "" {
cachedir = filepath.Join(xdgcache, "restic")
} else if home != "" {
cachedir = filepath.Join(home, ".cache", "restic")
return "", errors.New("unable to locate cache directory (XDG_CACHE_HOME and HOME unset)")
}
// windowsCacheDir returns the cache directory for Windows.
//
// Uses LOCALAPPDATA, where application data not synchronized between machines
// is stored. (Browser caches stored here).
func windowsCacheDir() (string, error) {
appdata := os.Getenv("LOCALAPPDATA")
if appdata == "" {
return "", errors.New("unable to locate cache directory (APPDATA unset)")
}
return filepath.Join(appdata, "restic"), nil
}
// darwinCacheDir returns the cache directory for darwin.
//
// Uses ~/Library/Caches/, which is recommended by Apple, see
// https://developer.apple.com/library/content/documentation/FileManagement/Conceptual/FileSystemProgrammingGuide/MacOSXDirectories/MacOSXDirectories.html
func darwinCacheDir() (string, error) {
home := os.Getenv("HOME")
if home == "" {
return "", errors.New("unable to locate cache directory (HOME unset)")
}
return filepath.Join(home, "Library", "Caches", "restic"), nil
}
// defaultCacheDir determines and creates the default cache directory for this
// system.
func defaultCacheDir() (string, error) {
var cachedir string
var err error
switch runtime.GOOS {
case "darwin":
cachedir, err = darwinCacheDir()
case "windows":
cachedir, err = windowsCacheDir()
default:
// Default to XDG for Linux and any other OSes.
cachedir, err = xdgCacheDir()
}
if err != nil {
return "", err
}
fi, err := fs.Stat(cachedir)