Rebrand overlay

Signed-off-by: jolheiser <john.olheiser@gmail.com>

README.md

@@ -1,7 +1,7 @@
-# XTFS
+# Overlay
-eXTended File System
+Overlay File System
 
-XTFS is an easy way to implement a file system in such a way that
+Overlay is an easy way to implement a file system in such a way that
 production assets can be overridden by assets on disk.
 
 ## Usage
@@ -12,14 +12,14 @@ package main
 import (
 	"embed"
 	
-	"go.jolheiser.com/xtfs"
+	"go.jolheiser.com/overlay"
 )
 
 //go:embed assets
 var assets embed.FS
 
 func main() {
-	xfs, err := xtfs.New("/var/lib/myapp/custom", assets)
+	ofs, err := overlay.New("/var/lib/myapp/custom", assets)
 	if err != nil {
 		panic(err)
     }
@@ -38,14 +38,14 @@ package main
 import (
 	"embed"
 	
-	"go.jolheiser.com/xtfs"
+	"go.jolheiser.com/overlay"
 )
 
 //go:embed assets
 var assets embed.FS
 
 func main() {
-	xfs, err := xtfs.New("/var/lib/myapp/custom", assets, xtfs.WithSub("assets"))
+	ofs, err := overlay.New("/var/lib/myapp/custom", assets, overlay.WithSub("assets"))
 	if err != nil {
 		panic(err)
     }

bench.txt

@@ -1,9 +1,9 @@
 go test -benchmem -bench=.
 goos: linux
 goarch: amd64
-pkg: go.jolheiser.com/xtfs
+pkg: go.jolheiser.com/overlay
 cpu: Intel(R) Core(TM) i7-4700MQ CPU @ 2.40GHz
-BenchmarkCache-8     	133917188	         8.970 ns/op	       0 B/op	       0 allocs/op
+BenchmarkCache-8     	134959974	         9.003 ns/op	       0 B/op	       0 allocs/op
-BenchmarkNoCache-8   	  931821	      1362 ns/op	     280 B/op	       4 allocs/op
+BenchmarkNoCache-8   	  897212	      1369 ns/op	     280 B/op	       4 allocs/op
 PASS
-ok  	go.jolheiser.com/xtfs	3.394s
+ok  	go.jolheiser.com/overlay	3.360s

go.mod

@@ -1,3 +1,3 @@
-module go.jolheiser.com/xtfs
+module go.jolheiser.com/overlay
 
 go 1.16

overlay.go

@@ -0,0 +1,79 @@
+package overlay
+
+import (
+	"io/fs"
+	"os"
+	"path"
+)
+
+// FS is an overlay File System
+type FS struct {
+	fs      fs.FS
+	root    string
+	doCache bool
+	cache   map[string]bool
+}
+
+func (f *FS) apn(name string) string {
+	return path.Join(f.root, name)
+}
+
+func (f *FS) exists(name string) bool {
+	if has, ok := f.cache[name]; ok && f.doCache {
+		return has
+	}
+	_, err := os.Stat(f.apn(name))
+	if err != nil {
+		f.cache[name] = false
+		return false
+	}
+	f.cache[name] = true
+	return true
+}
+
+// Open opens an fs.File, preferring disk
+func (f *FS) Open(name string) (fs.File, error) {
+	if f.exists(name) {
+		return os.Open(f.apn(name))
+	}
+	return f.fs.Open(name)
+}
+
+// Option is a functional option for an FS
+type Option func(*FS) error
+
+// New returns a new FS
+func New(root string, fs fs.FS, opts ...Option) (*FS, error) {
+	x := &FS{
+		fs:      fs,
+		root:    root,
+		doCache: true,
+		cache:   make(map[string]bool),
+	}
+
+	for _, opt := range opts {
+		if err := opt(x); err != nil {
+			return x, err
+		}
+	}
+
+	return x, nil
+}
+
+// WithSub sets a fs.Sub for an FS
+func WithSub(sub string) Option {
+	return func(x *FS) (err error) {
+		x.fs, err = fs.Sub(x.fs, sub)
+		return
+	}
+}
+
+// WithCaching sets a caching mode for an FS
+// Caching avoids subsequent os.Stat to determine if a file exists on disk
+// See bench.txt for differences in usage
+func WithCaching(doCache bool) Option {
+	return func(x *FS) error {
+		x.doCache = doCache
+		return nil
+	}
+}

overlay_test.go

@@ -1,4 +1,4 @@
-package xtfs
+package overlay
 
 import (
 	"embed"
@@ -15,7 +15,7 @@ func TestMain(m *testing.M) {
 	os.Exit(m.Run())
 }
 
-func TestXTFS(t *testing.T) {
+func TestOverlay(t *testing.T) {
 	tt := []struct {
 		Name     string
 		File     string
@@ -55,7 +55,7 @@ func TestXTFS(t *testing.T) {
 			}
 
 			if !strings.EqualFold(string(contents), tc.Expected) {
-				t.Logf("xtfs did not match:\n\tgot: %s\n\texpected: %s\n", string(contents), tc.Expected)
+				t.Logf("fs did not match:\n\tgot: %s\n\texpected: %s\n", string(contents), tc.Expected)
 				t.FailNow()
 			}
 		})
@@ -67,7 +67,7 @@ var emptyFS embed.FS
 func TestInvalid(t *testing.T) {
 	_, err := New("/var/lib/myapp/assets/custom", emptyFS)
 	if err != nil {
-		t.Log("invalid XTFS should not error explicitly")
+		t.Log("invalid FS should not error explicitly")
 		t.FailNow()
 	}
 }

xtfs.go

@@ -1,79 +0,0 @@
-package xtfs
-
-import (
-	"io/fs"
-	"os"
-	"path"
-)
-
-// XTFS is an eXTended File System
-type XTFS struct {
-	fs      fs.FS
-	root    string
-	doCache bool
-	cache   map[string]bool
-}
-
-func (x *XTFS) apn(name string) string {
-	return path.Join(x.root, name)
-}
-
-func (x *XTFS) exists(name string) bool {
-	if has, ok := x.cache[name]; ok && x.doCache {
-		return has
-	}
-	_, err := os.Stat(x.apn(name))
-	if err != nil {
-		x.cache[name] = false
-		return false
-	}
-	x.cache[name] = true
-	return true
-}
-
-// Open opens an fs.File, preferring disk
-func (x *XTFS) Open(name string) (fs.File, error) {
-	if x.exists(name) {
-		return os.Open(x.apn(name))
-	}
-	return x.fs.Open(name)
-}
-
-// Option is a functional option for an XTFS
-type Option func(*XTFS) error
-
-// New returns a new XTFS
-func New(root string, fs fs.FS, opts ...Option) (*XTFS, error) {
-	x := &XTFS{
-		fs:      fs,
-		root:    root,
-		doCache: true,
-		cache:   make(map[string]bool),
-	}
-
-	for _, opt := range opts {
-		if err := opt(x); err != nil {
-			return x, err
-		}
-	}
-
-	return x, nil
-}
-
-// WithSub sets a fs.Sub for an XTFS
-func WithSub(sub string) Option {
-	return func(x *XTFS) (err error) {
-		x.fs, err = fs.Sub(x.fs, sub)
-		return
-	}
-}
-
-// WithCaching sets a caching mode for an XTFS
-// Caching avoids subsequent os.Stat to determine if a file exists on disk
-// See bench.txt for differences in usage
-func WithCaching(doCache bool) Option {
-	return func(x *XTFS) error {
-		x.doCache = doCache
-		return nil
-	}
-}