forked from vikunja/vikunja
86 lines
2.2 KiB
Go
86 lines
2.2 KiB
Go
// Copyright 2017 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package cache
|
|
|
|
import (
|
|
"fmt"
|
|
"io/ioutil"
|
|
"log"
|
|
"os"
|
|
"path/filepath"
|
|
"sync"
|
|
)
|
|
|
|
// Default returns the default cache to use.
|
|
func Default() (*Cache, error) {
|
|
defaultOnce.Do(initDefaultCache)
|
|
return defaultCache, defaultDirErr
|
|
}
|
|
|
|
var (
|
|
defaultOnce sync.Once
|
|
defaultCache *Cache
|
|
)
|
|
|
|
// cacheREADME is a message stored in a README in the cache directory.
|
|
// Because the cache lives outside the normal Go trees, we leave the
|
|
// README as a courtesy to explain where it came from.
|
|
const cacheREADME = `This directory holds cached build artifacts from staticcheck.
|
|
`
|
|
|
|
// initDefaultCache does the work of finding the default cache
|
|
// the first time Default is called.
|
|
func initDefaultCache() {
|
|
dir := DefaultDir()
|
|
if err := os.MkdirAll(dir, 0777); err != nil {
|
|
log.Fatalf("failed to initialize build cache at %s: %s\n", dir, err)
|
|
}
|
|
if _, err := os.Stat(filepath.Join(dir, "README")); err != nil {
|
|
// Best effort.
|
|
ioutil.WriteFile(filepath.Join(dir, "README"), []byte(cacheREADME), 0666)
|
|
}
|
|
|
|
c, err := Open(dir)
|
|
if err != nil {
|
|
log.Fatalf("failed to initialize build cache at %s: %s\n", dir, err)
|
|
}
|
|
defaultCache = c
|
|
}
|
|
|
|
var (
|
|
defaultDirOnce sync.Once
|
|
defaultDir string
|
|
defaultDirErr error
|
|
)
|
|
|
|
// DefaultDir returns the effective STATICCHECK_CACHE setting.
|
|
func DefaultDir() string {
|
|
// Save the result of the first call to DefaultDir for later use in
|
|
// initDefaultCache. cmd/go/main.go explicitly sets GOCACHE so that
|
|
// subprocesses will inherit it, but that means initDefaultCache can't
|
|
// otherwise distinguish between an explicit "off" and a UserCacheDir error.
|
|
|
|
defaultDirOnce.Do(func() {
|
|
defaultDir = os.Getenv("STATICCHECK_CACHE")
|
|
if filepath.IsAbs(defaultDir) {
|
|
return
|
|
}
|
|
if defaultDir != "" {
|
|
defaultDirErr = fmt.Errorf("STATICCHECK_CACHE is not an absolute path")
|
|
return
|
|
}
|
|
|
|
// Compute default location.
|
|
dir, err := os.UserCacheDir()
|
|
if err != nil {
|
|
defaultDirErr = fmt.Errorf("STATICCHECK_CACHE is not defined and %v", err)
|
|
return
|
|
}
|
|
defaultDir = filepath.Join(dir, "staticcheck")
|
|
})
|
|
|
|
return defaultDir
|
|
}
|