diff options
author | Bjørn Erik Pedersen <bjorn.erik.pedersen@gmail.com> | 2019-01-02 11:58:32 +0100 |
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committer | Bjørn Erik Pedersen <bjorn.erik.pedersen@gmail.com> | 2019-01-02 14:25:37 +0100 |
commit | ce8a09a4c0661dece931ab1173e4f09e8e04aa38 (patch) | |
tree | 870372211e342312d0ab3034ee03285c6f698f9d /resources/resource_cache.go | |
parent | 669ada436787311cc5d02dae5b88e60a09adda58 (diff) |
resources: Move resource interfaces into its own package
Diffstat (limited to 'resources/resource_cache.go')
-rw-r--r-- | resources/resource_cache.go | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/resources/resource_cache.go b/resources/resource_cache.go new file mode 100644 index 000000000..8ff63beb0 --- /dev/null +++ b/resources/resource_cache.go @@ -0,0 +1,217 @@ +// Copyright 2019 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 resources + +import ( + "encoding/json" + "io" + "path" + "path/filepath" + "strings" + "sync" + + "github.com/gohugoio/hugo/resources/resource" + + "github.com/gohugoio/hugo/cache/filecache" + + "github.com/BurntSushi/locker" +) + +const ( + CACHE_CLEAR_ALL = "clear_all" + CACHE_OTHER = "other" +) + +type ResourceCache struct { + rs *Spec + + sync.RWMutex + cache map[string]resource.Resource + + fileCache *filecache.Cache + + // Provides named resource locks. + nlocker *locker.Locker +} + +// ResourceKeyPartition returns a partition name +// to allow for more fine grained cache flushes. +// It will return the file extension without the leading ".". If no +// extension, it will return "other". +func ResourceKeyPartition(filename string) string { + ext := strings.TrimPrefix(path.Ext(filepath.ToSlash(filename)), ".") + if ext == "" { + ext = CACHE_OTHER + } + return ext +} + +func newResourceCache(rs *Spec) *ResourceCache { + return &ResourceCache{ + rs: rs, + fileCache: rs.FileCaches.AssetsCache(), + cache: make(map[string]resource.Resource), + nlocker: locker.NewLocker(), + } +} + +func (c *ResourceCache) clear() { + c.Lock() + defer c.Unlock() + + c.cache = make(map[string]resource.Resource) + c.nlocker = locker.NewLocker() +} + +func (c *ResourceCache) Contains(key string) bool { + key = c.cleanKey(filepath.ToSlash(key)) + _, found := c.get(key) + return found +} + +func (c *ResourceCache) cleanKey(key string) string { + return strings.TrimPrefix(path.Clean(key), "/") +} + +func (c *ResourceCache) get(key string) (resource.Resource, bool) { + c.RLock() + defer c.RUnlock() + r, found := c.cache[key] + return r, found +} + +func (c *ResourceCache) GetOrCreate(partition, key string, f func() (resource.Resource, error)) (resource.Resource, error) { + key = c.cleanKey(path.Join(partition, key)) + // First check in-memory cache. + r, found := c.get(key) + if found { + return r, nil + } + // This is a potentially long running operation, so get a named lock. + c.nlocker.Lock(key) + + // Double check in-memory cache. + r, found = c.get(key) + if found { + c.nlocker.Unlock(key) + return r, nil + } + + defer c.nlocker.Unlock(key) + + r, err := f() + if err != nil { + return nil, err + } + + c.set(key, r) + + return r, nil + +} + +func (c *ResourceCache) getFilenames(key string) (string, string) { + filenameMeta := key + ".json" + filenameContent := key + ".content" + + return filenameMeta, filenameContent +} + +func (c *ResourceCache) getFromFile(key string) (filecache.ItemInfo, io.ReadCloser, transformedResourceMetadata, bool) { + c.RLock() + defer c.RUnlock() + + var meta transformedResourceMetadata + filenameMeta, filenameContent := c.getFilenames(key) + + _, jsonContent, _ := c.fileCache.GetBytes(filenameMeta) + if jsonContent == nil { + return filecache.ItemInfo{}, nil, meta, false + } + + if err := json.Unmarshal(jsonContent, &meta); err != nil { + return filecache.ItemInfo{}, nil, meta, false + } + + fi, rc, _ := c.fileCache.Get(filenameContent) + + return fi, rc, meta, rc != nil + +} + +// writeMeta writes the metadata to file and returns a writer for the content part. +func (c *ResourceCache) writeMeta(key string, meta transformedResourceMetadata) (filecache.ItemInfo, io.WriteCloser, error) { + filenameMeta, filenameContent := c.getFilenames(key) + raw, err := json.Marshal(meta) + if err != nil { + return filecache.ItemInfo{}, nil, err + } + + _, fm, err := c.fileCache.WriteCloser(filenameMeta) + if err != nil { + return filecache.ItemInfo{}, nil, err + } + defer fm.Close() + + if _, err := fm.Write(raw); err != nil { + return filecache.ItemInfo{}, nil, err + } + + fi, fc, err := c.fileCache.WriteCloser(filenameContent) + + return fi, fc, err + +} + +func (c *ResourceCache) set(key string, r resource.Resource) { + c.Lock() + defer c.Unlock() + c.cache[key] = r +} + +func (c *ResourceCache) DeletePartitions(partitions ...string) { + partitionsSet := map[string]bool{ + // Always clear out the resources not matching the partition. + "other": true, + } + for _, p := range partitions { + partitionsSet[p] = true + } + + if partitionsSet[CACHE_CLEAR_ALL] { + c.clear() + return + } + + c.Lock() + defer c.Unlock() + + for k := range c.cache { + clear := false + partIdx := strings.Index(k, "/") + if partIdx == -1 { + clear = true + } else { + partition := k[:partIdx] + if partitionsSet[partition] { + clear = true + } + } + + if clear { + delete(c.cache, k) + } + } + +} |