nametransform: move diriv cache into it's own package

Needs some space to grow.

renamed:    internal/nametransform/diriv_cache.go -> internal/nametransform/dirivcache/dirivcache.go

internal/nametransform/diriv.go

@@ -125,7 +125,7 @@ func (be *NameTransform) EncryptPathDirIV(plainPath string, rootDir string) (cip
 	// Check if the DirIV is cached. This catches the case of the user iterating
 	// over files in a directory pretty well.
 	parentDir := filepath.Dir(plainPath)
-	iv, cParentDir := be.DirIVCache.lookup(parentDir)
+	iv, cParentDir := be.DirIVCache.Lookup(parentDir)
 	if iv != nil {
 		cBaseName := be.encryptAndHashName(baseName, iv)
 		return filepath.Join(cParentDir, cBaseName), nil
@@ -138,7 +138,7 @@ func (be *NameTransform) EncryptPathDirIV(plainPath string, rootDir string) (cip
 	// cached. Then we can skip a few items in the directory walk.
 	// This catches the case of walking directories recursively.
 	parentDir2 := filepath.Dir(parentDir)
-	iv, cParentDir = be.DirIVCache.lookup(parentDir2)
+	iv, cParentDir = be.DirIVCache.Lookup(parentDir2)
 	if iv != nil {
 		parentDirBase := filepath.Base(parentDir)
 		cBaseName := be.encryptAndHashName(parentDirBase, iv)
@@ -159,6 +159,6 @@ func (be *NameTransform) EncryptPathDirIV(plainPath string, rootDir string) (cip
 	}
 	// Cache the final DirIV
 	cParentDir = filepath.Dir(cipherPath)
-	be.DirIVCache.store(parentDir, iv, cParentDir)
+	be.DirIVCache.Store(parentDir, iv, cParentDir)
 	return cipherPath, nil
 }

internal/nametransform/dirivcache/dirivcache.go

@@ -1,4 +1,4 @@
-package nametransform
+package dirivcache
 
 import (
 	"sync"
@@ -7,7 +7,7 @@ import (
 
 // Single-entry DirIV cache. Stores the directory IV and the encrypted
 // path.
-type dirIVCache struct {
+type DirIVCache struct {
 	// Directory the DirIV belongs to
 	dir string
 	// Time the entry expires.
@@ -28,7 +28,7 @@ type dirIVCache struct {
 }
 
 // lookup - fetch entry for "dir" from the cache
-func (c *dirIVCache) lookup(dir string) ([]byte, string) {
+func (c *DirIVCache) Lookup(dir string) ([]byte, string) {
 	c.RLock()
 	defer c.RUnlock()
 	if c.cleared || c.dir != dir {
@@ -42,7 +42,7 @@ func (c *dirIVCache) lookup(dir string) ([]byte, string) {
 }
 
 // store - write entry for "dir" into the cache
-func (c *dirIVCache) store(dir string, iv []byte, cDir string) {
+func (c *DirIVCache) Store(dir string, iv []byte, cDir string) {
 	c.Lock()
 	defer c.Unlock()
 	c.cleared = false
@@ -56,7 +56,7 @@ func (c *dirIVCache) store(dir string, iv []byte, cDir string) {
 // Clear ... clear the cache.
 // Exported because it is called from fusefrontend when directories are
 // renamed or deleted.
-func (c *dirIVCache) Clear() {
+func (c *DirIVCache) Clear() {
 	c.Lock()
 	defer c.Unlock()
 	c.cleared = true

internal/nametransform/names.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/rfjakob/eme"
 
+	"github.com/rfjakob/gocryptfs/internal/nametransform/dirivcache"
 	"github.com/rfjakob/gocryptfs/internal/tlog"
 )
 
@@ -16,7 +17,7 @@ import (
 type NameTransform struct {
 	emeCipher  *eme.EMECipher
 	longNames  bool
-	DirIVCache dirIVCache
+	DirIVCache dirivcache.DirIVCache
 	// B64 = either base64.URLEncoding or base64.RawURLEncoding, depeding
 	// on the Raw64 feature flag
 	B64 *base64.Encoding