hugo/tpl/data/cache.go
2017-06-13 19:12:10 +02:00

83 lines
2.1 KiB
Go

// Copyright 2017 The Hugo Authors. All rights reserved.
//
// 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 data
import (
"errors"
"net/url"
"sync"
"github.com/gohugoio/hugo/config"
"github.com/gohugoio/hugo/helpers"
"github.com/spf13/afero"
)
var cacheMu sync.RWMutex
// getCacheFileID returns the cache ID for a string.
func getCacheFileID(cfg config.Provider, id string) string {
return cfg.GetString("cacheDir") + url.QueryEscape(id)
}
// getCache returns the content for an ID from the file cache or an error.
// If the ID is not found, return nil,nil.
func getCache(id string, fs afero.Fs, cfg config.Provider, ignoreCache bool) ([]byte, error) {
if ignoreCache {
return nil, nil
}
cacheMu.RLock()
defer cacheMu.RUnlock()
fID := getCacheFileID(cfg, id)
isExists, err := helpers.Exists(fID, fs)
if err != nil {
return nil, err
}
if !isExists {
return nil, nil
}
return afero.ReadFile(fs, fID)
}
// writeCache writes bytes associated with an ID into the file cache.
func writeCache(id string, c []byte, fs afero.Fs, cfg config.Provider, ignoreCache bool) error {
if ignoreCache {
return nil
}
cacheMu.Lock()
defer cacheMu.Unlock()
fID := getCacheFileID(cfg, id)
f, err := fs.Create(fID)
if err != nil {
return errors.New("Error: " + err.Error() + ". Failed to create file: " + fID)
}
defer f.Close()
n, err := f.Write(c)
if err != nil {
return errors.New("Error: " + err.Error() + ". Failed to write to file: " + fID)
}
if n == 0 {
return errors.New("No bytes written to file: " + fID)
}
return nil
}
func deleteCache(id string, fs afero.Fs, cfg config.Provider) error {
return fs.Remove(getCacheFileID(cfg, id))
}