vfs: keep track of directories in the cache also #1860
This makes managing empty directories more reliable.
This commit is contained in:
Nick Craig-Wood
parent
0978957a2e
commit
c16ac697a9
208
vfs/cache.go
208
vfs/cache.go
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@ -8,6 +8,7 @@ import (
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"path"
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"path/filepath"
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"runtime"
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"sort"
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"strings"
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"sync"
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"time"
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@ -66,18 +67,19 @@ type cache struct {
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opt *Options // vfs Options
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root string // root of the cache directory
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itemMu sync.Mutex // protects the next two maps
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item map[string]*cacheItem // files in the cache
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item map[string]*cacheItem // files/directories in the cache
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}
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// cacheItem is stored in the item map
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type cacheItem struct {
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opens int // number of times file is open
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atime time.Time // last time file was accessed
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opens int // number of times file is open
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atime time.Time // last time file was accessed
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isFile bool // if this is a file or a directory
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}
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// newCacheItem returns an item for the cache
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func newCacheItem() *cacheItem {
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return &cacheItem{atime: time.Now()}
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func newCacheItem(isFile bool) *cacheItem {
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return &cacheItem{atime: time.Now(), isFile: isFile}
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}
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// newCache creates a new cache heirachy for f
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@ -112,47 +114,65 @@ func newCache(ctx context.Context, f fs.Fs, opt *Options) (*cache, error) {
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return c, nil
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}
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// findParent returns the parent directory of name, or "" for the root
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func findParent(name string) string {
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parent := path.Dir(name)
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if parent == "." || parent == "/" {
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parent = ""
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}
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return parent
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}
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// toOSPath turns a remote relative name into an OS path in the cache
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func (c *cache) toOSPath(name string) string {
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return filepath.Join(c.root, filepath.FromSlash(name))
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}
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// mkdir makes the directory for name in the cache and returns an os
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// path for the file
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func (c *cache) mkdir(name string) (string, error) {
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parent := path.Dir(name)
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if parent == "." {
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parent = ""
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}
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parent := findParent(name)
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leaf := path.Base(name)
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parentPath := filepath.Join(c.root, filepath.FromSlash(parent))
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parentPath := c.toOSPath(parent)
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err := os.MkdirAll(parentPath, 0700)
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if err != nil {
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return "", errors.Wrap(err, "make cache directory failed")
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}
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c.cacheDir(parent)
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return filepath.Join(parentPath, leaf), nil
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}
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// _get gets name from the cache or creates a new one
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//
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// name should be a remote path not an osPath
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//
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// must be called with itemMu held
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func (c *cache) _get(name string) *cacheItem {
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func (c *cache) _get(isFile bool, name string) *cacheItem {
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item := c.item[name]
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if item == nil {
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item = newCacheItem()
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item = newCacheItem(isFile)
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c.item[name] = item
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}
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return item
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}
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// get gets name from the cache or creates a new one
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//
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// name should be a remote path not an osPath
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func (c *cache) get(name string) *cacheItem {
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c.itemMu.Lock()
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item := c._get(name)
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item := c._get(true, name)
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c.itemMu.Unlock()
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return item
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}
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// updateTime sets the atime of the name to that passed in if it is
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// newer than the existing or there isn't an existing time.
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//
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// name should be a remote path not an osPath
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func (c *cache) updateTime(name string, when time.Time) {
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c.itemMu.Lock()
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item := c._get(name)
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item := c._get(true, name)
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if when.Sub(item.atime) > 0 {
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fs.Debugf(name, "updateTime: setting atime to %v", when)
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item.atime = when
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@ -160,30 +180,79 @@ func (c *cache) updateTime(name string, when time.Time) {
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c.itemMu.Unlock()
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}
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// _open marks name as open, must be called with the lock held
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//
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// name should be a remote path not an osPath
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func (c *cache) _open(isFile bool, name string) {
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for {
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item := c._get(isFile, name)
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item.opens++
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item.atime = time.Now()
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if name == "" {
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break
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}
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isFile = false
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name = findParent(name)
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}
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}
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// open marks name as open
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//
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// name should be a remote path not an osPath
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func (c *cache) open(name string) {
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c.itemMu.Lock()
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item := c._get(name)
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item.opens++
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item.atime = time.Now()
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c._open(true, name)
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c.itemMu.Unlock()
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}
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// cacheDir marks a directory and its parents as being in the cache
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//
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// name should be a remote path not an osPath
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func (c *cache) cacheDir(name string) {
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c.itemMu.Lock()
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defer c.itemMu.Unlock()
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for {
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item := c.item[name]
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if item != nil {
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break
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}
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c.item[name] = newCacheItem(false)
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if name == "" {
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break
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}
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name = findParent(name)
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}
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}
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// _close marks name as closed - must be called with the lock held
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func (c *cache) _close(isFile bool, name string) {
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for {
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item := c._get(isFile, name)
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item.opens--
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item.atime = time.Now()
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if item.opens < 0 {
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fs.Errorf(name, "cache: double close")
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}
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if name == "" {
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break
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}
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isFile = false
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name = findParent(name)
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}
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}
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// close marks name as closed
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//
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// name should be a remote path not an osPath
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func (c *cache) close(name string) {
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c.itemMu.Lock()
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item := c._get(name)
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item.opens--
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item.atime = time.Now()
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if item.opens < 0 {
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fs.Errorf(name, "cache: double close")
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}
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c._close(true, name)
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c.itemMu.Unlock()
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}
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// remove should be called if name is deleted
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func (c *cache) remove(name string) {
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osPath := filepath.Join(c.root, filepath.FromSlash(name))
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osPath := c.toOSPath(name)
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err := os.Remove(osPath)
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if err != nil && !os.IsNotExist(err) {
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fs.Errorf(name, "Failed to remove from cache: %v", err)
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@ -192,29 +261,55 @@ func (c *cache) remove(name string) {
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}
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}
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// removeDir should be called if dir is deleted and returns true if
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// the directory is gone.
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func (c *cache) removeDir(dir string) bool {
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osPath := c.toOSPath(dir)
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err := os.Remove(osPath)
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if err == nil || os.IsNotExist(err) {
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return true
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}
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if !os.IsExist(err) {
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fs.Errorf(dir, "Failed to remove cached dir: %v", err)
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}
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return false
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}
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// cleanUp empties the cache of everything
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func (c *cache) cleanUp() error {
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return os.RemoveAll(c.root)
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}
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// updateAtimes walks the cache updating any atimes it finds
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func (c *cache) updateAtimes() error {
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// walk walks the cache calling the function
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func (c *cache) walk(fn func(osPath string, fi os.FileInfo, name string) error) error {
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return filepath.Walk(c.root, func(osPath string, fi os.FileInfo, err error) error {
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if err != nil {
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return err
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}
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if !fi.IsDir() {
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// Find path relative to the cache root
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name, err := filepath.Rel(c.root, osPath)
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if err != nil {
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return errors.Wrap(err, "filepath.Rel failed in updatAtimes")
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}
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// And convert into slashes
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name = filepath.ToSlash(name)
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// Find path relative to the cache root
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name, err := filepath.Rel(c.root, osPath)
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if err != nil {
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return errors.Wrap(err, "filepath.Rel failed in walk")
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}
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if name == "." {
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name = ""
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}
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// And convert into slashes
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name = filepath.ToSlash(name)
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return fn(osPath, fi, name)
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})
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}
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// updateAtimes walks the cache updating any atimes it finds
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func (c *cache) updateAtimes() error {
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return c.walk(func(osPath string, fi os.FileInfo, name string) error {
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if !fi.IsDir() {
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// Update the atime with that of the file
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atime := times.Get(fi).AccessTime()
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c.updateTime(name, atime)
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} else {
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c.cacheDir(name)
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}
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return nil
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})
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@ -222,17 +317,39 @@ func (c *cache) updateAtimes() error {
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// purgeOld gets rid of any files that are over age
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func (c *cache) purgeOld(maxAge time.Duration) {
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c._purgeOld(maxAge, c.remove, c.removeDir)
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}
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func (c *cache) _purgeOld(maxAge time.Duration, remove func(name string), removeDir func(name string) bool) {
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c.itemMu.Lock()
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defer c.itemMu.Unlock()
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cutoff := time.Now().Add(-maxAge)
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for name, item := range c.item {
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// If not locked and access time too long ago - delete the file
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dt := item.atime.Sub(cutoff)
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// fs.Debugf(name, "atime=%v cutoff=%v, dt=%v", item.atime, cutoff, dt)
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if item.opens == 0 && dt < 0 {
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c.remove(name)
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// Remove the entry
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delete(c.item, name)
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if item.isFile && item.opens == 0 {
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// If not locked and access time too long ago - delete the file
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dt := item.atime.Sub(cutoff)
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// fs.Debugf(name, "atime=%v cutoff=%v, dt=%v", item.atime, cutoff, dt)
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if dt < 0 {
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remove(name)
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// Remove the entry
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delete(c.item, name)
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}
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}
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}
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// now find any empty directories
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var dirs []string
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for name, item := range c.item {
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if !item.isFile && item.opens == 0 {
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dirs = append(dirs, name)
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}
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}
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// remove empty directories in reverse alphabetical order
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sort.Strings(dirs)
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for i := len(dirs) - 1; i >= 0; i-- {
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dir := dirs[i]
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// Remove the entry
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if removeDir(dir) {
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delete(c.item, dir)
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}
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}
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}
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@ -253,14 +370,9 @@ func (c *cache) clean() {
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fs.Errorf(nil, "Error traversing cache %q: %v", c.root, err)
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}
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// Now remove any files that are over age
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// Now remove any files that are over age and any empty
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// directories
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c.purgeOld(c.opt.CacheMaxAge)
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// Now tidy up any empty directories
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err = fs.Rmdirs(c.f, "")
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if err != nil {
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fs.Errorf(c.f, "Failed to remove empty directories from cache: %v", err)
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}
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}
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// cleaner calls clean at regular intervals
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@ -1,10 +1,13 @@
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package vfs
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import (
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"fmt"
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"io/ioutil"
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"log"
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"os"
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"path/filepath"
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"sort"
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"strings"
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"testing"
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"time"
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@ -44,6 +47,18 @@ func TestCacheModeType(t *testing.T) {
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assert.Equal(t, "string", m.Type())
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}
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// convert c.item to a string
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func itemAsString(c *cache) string {
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c.itemMu.Lock()
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defer c.itemMu.Unlock()
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var out []string
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for name, item := range c.item {
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out = append(out, fmt.Sprintf("name=%q isFile=%v opens=%d", name, item.isFile, item.opens))
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}
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sort.Strings(out)
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return strings.Join(out, "\n")
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}
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func TestCacheNew(t *testing.T) {
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r := fstest.NewRun(t)
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defer r.Finalise()
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@ -56,11 +71,13 @@ func TestCacheNew(t *testing.T) {
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assert.Contains(t, c.root, "vfs")
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assert.Contains(t, c.f.Root(), filepath.Base(r.Fremote.Root()))
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assert.Equal(t, "", itemAsString(c))
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// mkdir
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p, err := c.mkdir("potato")
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require.NoError(t, err)
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assert.Equal(t, "potato", filepath.Base(p))
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assert.Equal(t, `name="" isFile=false opens=0`, itemAsString(c))
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fi, err := os.Stat(filepath.Dir(p))
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require.NoError(t, err)
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@ -87,7 +104,11 @@ func TestCacheNew(t *testing.T) {
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assert.Equal(t, 0, item.opens)
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// open
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assert.Equal(t, `name="" isFile=false opens=0
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name="potato" isFile=true opens=0`, itemAsString(c))
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c.open("potato")
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assert.Equal(t, `name="" isFile=false opens=1
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name="potato" isFile=true opens=1`, itemAsString(c))
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item = c.get("potato")
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assert.WithinDuration(t, time.Now(), item.atime, time.Second)
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assert.Equal(t, 1, item.opens)
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@ -107,6 +128,8 @@ func TestCacheNew(t *testing.T) {
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item.atime = time.Now().Add(-24 * time.Hour)
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err = c.updateAtimes()
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require.NoError(t, err)
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assert.Equal(t, `name="" isFile=false opens=1
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name="potato" isFile=true opens=1`, itemAsString(c))
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item = c.get("potato")
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assert.Equal(t, atime, item.atime)
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@ -116,8 +139,14 @@ func TestCacheNew(t *testing.T) {
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assert.NoError(t, err)
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// close
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assert.Equal(t, `name="" isFile=false opens=1
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name="potato" isFile=true opens=1`, itemAsString(c))
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c.updateTime("potato", t2)
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assert.Equal(t, `name="" isFile=false opens=1
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name="potato" isFile=true opens=1`, itemAsString(c))
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c.close("potato")
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assert.Equal(t, `name="" isFile=false opens=0
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name="potato" isFile=true opens=0`, itemAsString(c))
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item = c.get("potato")
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assert.WithinDuration(t, time.Now(), item.atime, time.Second)
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assert.Equal(t, 0, item.opens)
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@ -142,3 +171,148 @@ func TestCacheNew(t *testing.T) {
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_, err = os.Stat(c.root)
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assert.True(t, os.IsNotExist(err))
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}
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func TestCacheOpens(t *testing.T) {
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r := fstest.NewRun(t)
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defer r.Finalise()
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ctx, cancel := context.WithCancel(context.Background())
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defer cancel()
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c, err := newCache(ctx, r.Fremote, &DefaultOpt)
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require.NoError(t, err)
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assert.Equal(t, "", itemAsString(c))
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c.open("potato")
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assert.Equal(t, `name="" isFile=false opens=1
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name="potato" isFile=true opens=1`, itemAsString(c))
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c.open("potato")
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assert.Equal(t, `name="" isFile=false opens=2
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name="potato" isFile=true opens=2`, itemAsString(c))
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c.close("potato")
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assert.Equal(t, `name="" isFile=false opens=1
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name="potato" isFile=true opens=1`, itemAsString(c))
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c.close("potato")
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assert.Equal(t, `name="" isFile=false opens=0
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name="potato" isFile=true opens=0`, itemAsString(c))
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c.open("potato")
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c.open("a/b/c/d/one")
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c.open("a/b/c/d/e/two")
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c.open("a/b/c/d/e/f/three")
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assert.Equal(t, `name="" isFile=false opens=4
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name="a" isFile=false opens=3
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name="a/b" isFile=false opens=3
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name="a/b/c" isFile=false opens=3
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name="a/b/c/d" isFile=false opens=3
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name="a/b/c/d/e" isFile=false opens=2
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name="a/b/c/d/e/f" isFile=false opens=1
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name="a/b/c/d/e/f/three" isFile=true opens=1
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name="a/b/c/d/e/two" isFile=true opens=1
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name="a/b/c/d/one" isFile=true opens=1
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name="potato" isFile=true opens=1`, itemAsString(c))
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c.close("potato")
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c.close("a/b/c/d/one")
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c.close("a/b/c/d/e/two")
|
||||
c.close("a/b/c/d/e/f/three")
|
||||
assert.Equal(t, `name="" isFile=false opens=0
|
||||
name="a" isFile=false opens=0
|
||||
name="a/b" isFile=false opens=0
|
||||
name="a/b/c" isFile=false opens=0
|
||||
name="a/b/c/d" isFile=false opens=0
|
||||
name="a/b/c/d/e" isFile=false opens=0
|
||||
name="a/b/c/d/e/f" isFile=false opens=0
|
||||
name="a/b/c/d/e/f/three" isFile=true opens=0
|
||||
name="a/b/c/d/e/two" isFile=true opens=0
|
||||
name="a/b/c/d/one" isFile=true opens=0
|
||||
name="potato" isFile=true opens=0`, itemAsString(c))
|
||||
|
||||
}
|
||||
|
||||
func TestCacheCacheDir(t *testing.T) {
|
||||
r := fstest.NewRun(t)
|
||||
defer r.Finalise()
|
||||
|
||||
ctx, cancel := context.WithCancel(context.Background())
|
||||
defer cancel()
|
||||
|
||||
c, err := newCache(ctx, r.Fremote, &DefaultOpt)
|
||||
require.NoError(t, err)
|
||||
|
||||
assert.Equal(t, "", itemAsString(c))
|
||||
|
||||
c.cacheDir("dir")
|
||||
assert.Equal(t, `name="" isFile=false opens=0
|
||||
name="dir" isFile=false opens=0`, itemAsString(c))
|
||||
|
||||
c.cacheDir("dir/sub")
|
||||
assert.Equal(t, `name="" isFile=false opens=0
|
||||
name="dir" isFile=false opens=0
|
||||
name="dir/sub" isFile=false opens=0`, itemAsString(c))
|
||||
|
||||
c.cacheDir("dir/sub2/subsub2")
|
||||
assert.Equal(t, `name="" isFile=false opens=0
|
||||
name="dir" isFile=false opens=0
|
||||
name="dir/sub" isFile=false opens=0
|
||||
name="dir/sub2" isFile=false opens=0
|
||||
name="dir/sub2/subsub2" isFile=false opens=0`, itemAsString(c))
|
||||
}
|
||||
|
||||
func TestCachePurgeOld(t *testing.T) {
|
||||
r := fstest.NewRun(t)
|
||||
defer r.Finalise()
|
||||
|
||||
ctx, cancel := context.WithCancel(context.Background())
|
||||
defer cancel()
|
||||
|
||||
c, err := newCache(ctx, r.Fremote, &DefaultOpt)
|
||||
require.NoError(t, err)
|
||||
|
||||
// Test funcs
|
||||
var removed []string
|
||||
removedDir := true
|
||||
removeFile := func(name string) {
|
||||
removed = append(removed, name)
|
||||
}
|
||||
removeDir := func(name string) bool {
|
||||
if removedDir {
|
||||
removed = append(removed, name+"/")
|
||||
}
|
||||
return removedDir
|
||||
}
|
||||
|
||||
removed = nil
|
||||
c._purgeOld(-10*time.Second, removeFile, removeDir)
|
||||
assert.Equal(t, []string(nil), removed)
|
||||
|
||||
c.open("sub/dir/potato")
|
||||
c.close("sub/dir/potato")
|
||||
|
||||
assert.Equal(t, `name="" isFile=false opens=0
|
||||
name="sub" isFile=false opens=0
|
||||
name="sub/dir" isFile=false opens=0
|
||||
name="sub/dir/potato" isFile=true opens=0`, itemAsString(c))
|
||||
|
||||
removed = nil
|
||||
removedDir = false
|
||||
c._purgeOld(10*time.Second, removeFile, removeDir)
|
||||
assert.Equal(t, []string(nil), removed)
|
||||
|
||||
assert.Equal(t, `name="" isFile=false opens=0
|
||||
name="sub" isFile=false opens=0
|
||||
name="sub/dir" isFile=false opens=0
|
||||
name="sub/dir/potato" isFile=true opens=0`, itemAsString(c))
|
||||
|
||||
removed = nil
|
||||
removedDir = true
|
||||
c._purgeOld(-10*time.Second, removeFile, removeDir)
|
||||
assert.Equal(t, []string{
|
||||
"sub/dir/potato",
|
||||
"sub/dir/",
|
||||
"sub/",
|
||||
"/",
|
||||
}, removed)
|
||||
|
||||
assert.Equal(t, ``, itemAsString(c))
|
||||
}
|
||||
|
|
|
|||
|
|
@ -129,7 +129,7 @@ func (fh *RWFileHandle) openPending(truncate bool) (err error) {
|
|||
}
|
||||
fh.File = fd
|
||||
fh.opened = true
|
||||
fh.d.vfs.cache.open(fh.osPath)
|
||||
fh.d.vfs.cache.open(fh.remote)
|
||||
fh.d.addObject(fh.file) // make sure the directory has this object in it now
|
||||
return nil
|
||||
}
|
||||
|
|
@ -196,7 +196,7 @@ func (fh *RWFileHandle) close() (err error) {
|
|||
fh.file.setSize(fi.Size())
|
||||
}
|
||||
}
|
||||
fh.d.vfs.cache.close(fh.osPath)
|
||||
fh.d.vfs.cache.close(fh.remote)
|
||||
|
||||
// Close the underlying file
|
||||
err = fh.File.Close()
|
||||
|
|
|
|||
Loading…
Reference in New Issue