feat(storage): add core virtual file system (#347)

.gitignore

@@ -29,3 +29,5 @@ i18n/temp/*
 
 dist/
 MUSICO/
+shroud.txt
+__A/

.vscode/settings.json

@@ -2,10 +2,13 @@
   "cSpell.words": [
     "argh",
     "Assisable",
+    "avfs",
+    "beezledub",
     "bodyclose",
     "booter",
     "bootstrapper",
     "chardata",
+    "cobrass",
     "deadcode",
     "deepcopy",
     "depguard",
@@ -16,6 +19,7 @@
     "exportloopref",
     "extendio",
     "Fastward",
+    "faydeaudeau",
     "fieldalignment",
     "Flacs",
     "forloc",
@@ -27,7 +31,9 @@
     "gofmt",
     "Goid",
     "goimports",
+    "gola",
     "goleak",
+    "gomega",
     "gomnd",
     "gosec",
     "gosimple",
@@ -42,21 +48,29 @@
     "linters",
     "logr",
     "lorax",
+    "memfs",
     "mohae",
     "MUSICO",
     "nakedret",
     "natefinch",
     "navi",
+    "newname",
+    "newpath",
     "nicksnyder",
     "nolint",
     "nolintlint",
+    "oldname",
+    "oldpath",
     "onecontext",
+    "onsi",
     "prealloc",
     "rabbitweed",
     "repath",
     "Resumer",
     "rxgo",
+    "samber",
     "sidewalk",
+    "snivilised",
     "staticcheck",
     "structcheck",
     "stylecheck",

Test/data/storage/Nephilim/Mourning Sun/info.requiem.txt

@@ -0,0 +1 @@
+requiem-content

go.mod

@@ -18,6 +18,7 @@ require (
 )
 
 require (
+	github.com/avfs/avfs v0.33.0 // indirect
 	github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572 // indirect
 	github.com/google/pprof v0.0.0-20230406165453-00490a63f317 // indirect
 	github.com/rogpeppe/go-internal v1.11.0 // indirect

go.sum

@@ -1,5 +1,7 @@
 github.com/BurntSushi/toml v1.0.0 h1:dtDWrepsVPfW9H/4y7dDgFc2MBUSeJhlaDtK13CxFlU=
 github.com/BurntSushi/toml v1.0.0/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
+github.com/avfs/avfs v0.33.0 h1:5WQXbUbr6VS7aani39ZN2Vrd/s3wLnyih1Sc4ExWTxs=
+github.com/avfs/avfs v0.33.0/go.mod h1:Q59flcFRYe9KYkNMfrLUJney3yeKGQpcWRyxsDBW7vI=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=

xfs/storage/mem-fs.go

@@ -0,0 +1,120 @@
+package storage
+
+import (
+	"fmt"
+	"io/fs"
+	"os"
+
+	"github.com/avfs/avfs/vfs/memfs"
+	"github.com/pkg/errors"
+)
+
+type memFS struct {
+	backend VirtualBackend
+	mfs     *memfs.MemFS
+}
+
+func UseMemFS() VirtualFS {
+	return &memFS{
+		backend: "mem",
+		mfs:     memfs.New(),
+	}
+}
+
+func (ms *memFS) Backend() VirtualBackend {
+	return ms.backend
+}
+
+// interface ExistsInFS
+
+func (ms *memFS) FileExists(path string) bool {
+	result := false
+	if info, err := ms.mfs.Lstat(path); err == nil {
+		result = !info.IsDir()
+	}
+
+	return result
+}
+
+func (ms *memFS) DirectoryExists(path string) bool {
+	result := false
+	if info, err := ms.mfs.Lstat(path); err == nil {
+		result = info.IsDir()
+	}
+
+	return result
+}
+
+// end: interface ExistsInFS
+
+// interface ReadOnlyVirtualFS
+
+func (ms *memFS) Lstat(path string) (fs.FileInfo, error) {
+	return ms.mfs.Lstat(path)
+}
+
+func (ms *memFS) Stat(path string) (fs.FileInfo, error) {
+	return ms.mfs.Stat(path)
+}
+
+func (ms *memFS) ReadFile(name string) ([]byte, error) {
+	return ms.mfs.ReadFile(name)
+}
+
+func (ms *memFS) ReadDir(name string) ([]os.DirEntry, error) {
+	return ms.mfs.ReadDir(name)
+}
+
+// end: interface ReadOnlyVirtualFS
+
+// interface WriteToFS
+
+func (ms *memFS) Chmod(name string, mode os.FileMode) error {
+	return ms.mfs.Chmod(name, mode)
+}
+
+func (ms *memFS) Chown(name string, uid, gid int) error {
+	return ms.mfs.Chown(name, uid, gid)
+}
+
+func (ms *memFS) Create(name string) (*os.File, error) {
+	f, err := ms.mfs.Create(name)
+
+	if file, ok := f.(*os.File); ok {
+		return file, err
+	}
+
+	return nil, errors.Wrap(err,
+		fmt.Sprintf("file '%v' creation in '%v' failed", name, ms.backend),
+	)
+}
+
+func (ms *memFS) Link(oldname, newname string) error {
+	return ms.mfs.Link(oldname, newname)
+}
+
+func (ms *memFS) Mkdir(name string, perm fs.FileMode) error {
+	return ms.mfs.Mkdir(name, perm)
+}
+
+func (ms *memFS) MkdirAll(path string, perm os.FileMode) error {
+	return ms.mfs.MkdirAll(path, perm)
+}
+
+func (ms *memFS) Remove(name string) error {
+	return ms.mfs.Remove(name)
+}
+
+func (ms *memFS) RemoveAll(path string) error {
+	return ms.mfs.RemoveAll(path)
+}
+
+func (ms *memFS) Rename(oldpath, newpath string) error {
+	return ms.mfs.Rename(oldpath, newpath)
+}
+
+func (ms *memFS) WriteFile(name string, data []byte, perm os.FileMode) error {
+	return ms.mfs.WriteFile(name, data, perm)
+}
+
+// end: interface WriteToFS

xfs/storage/native-fs.go

@@ -0,0 +1,106 @@
+package storage
+
+import (
+	"io/fs"
+	"os"
+)
+
+type nativeFS struct {
+	backend VirtualBackend
+}
+
+func UseNativeFS() VirtualFS {
+	return &nativeFS{
+		backend: "native",
+	}
+}
+
+func (ns *nativeFS) Backend() VirtualBackend {
+	return ns.backend
+}
+
+// interface ExistsInFS
+
+func (ns *nativeFS) FileExists(path string) bool {
+	result := false
+	if info, err := os.Lstat(path); err == nil {
+		result = !info.IsDir()
+	}
+
+	return result
+}
+
+func (ns *nativeFS) DirectoryExists(path string) bool {
+	result := false
+	if info, err := os.Lstat(path); err == nil {
+		result = info.IsDir()
+	}
+
+	return result
+}
+
+// end: interface ExistsInFS
+
+// interface ReadOnlyVirtualFS
+
+func (ns *nativeFS) Lstat(path string) (fs.FileInfo, error) {
+	return os.Lstat(path)
+}
+
+func (ns *nativeFS) Stat(path string) (fs.FileInfo, error) {
+	return os.Stat(path)
+}
+
+func (ns *nativeFS) ReadFile(name string) ([]byte, error) {
+	return os.ReadFile(name)
+}
+
+func (ns *nativeFS) ReadDir(name string) ([]os.DirEntry, error) {
+	return os.ReadDir(name)
+}
+
+// end: interface ReadOnlyVirtualFS
+
+func (ns *nativeFS) Chmod(name string, mode os.FileMode) error {
+	return os.Chmod(name, mode)
+}
+
+func (ns *nativeFS) Chown(name string, uid, gid int) error {
+	return os.Chown(name, uid, gid)
+}
+
+func (ns *nativeFS) Create(name string) (*os.File, error) {
+	return os.Create(name)
+}
+
+// interface WriteToFS
+
+func (ns *nativeFS) Link(oldname, newname string) error {
+	return os.Link(oldname, newname)
+}
+
+func (ns *nativeFS) Mkdir(name string, perm fs.FileMode) error {
+	return os.Mkdir(name, perm)
+}
+
+func (ns *nativeFS) MkdirAll(path string, perm os.FileMode) error {
+	return os.MkdirAll(path, perm)
+}
+
+func (ns *nativeFS) Remove(name string) error {
+	return os.Remove(name)
+}
+
+func (ns *nativeFS) RemoveAll(path string) error {
+	return os.RemoveAll(path)
+}
+
+func (ns *nativeFS) Rename(oldpath, newpath string) error {
+	return os.Rename(oldpath, newpath)
+}
+
+func (ns *nativeFS) WriteFile(name string, data []byte, perm os.FileMode) error {
+	return os.WriteFile(name, data, perm)
+}
+
+// end: interface WriteToFS