18600: Support fs.FS interface.

Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tom@curii.com>

diff --git a/sdk/go/arvados/fs_base.go b/sdk/go/arvados/fs_base.go
index 80b803729349dd500de0e7832288f593c41ab60c..387b6a737ff334cba74cb44dc83761a88fd56571 100644 (file)
--- a/sdk/go/arvados/fs_base.go
+++ b/sdk/go/arvados/fs_base.go
@@ -8,6 +8,7 @@ import (
        "errors"
        "fmt"
        "io"
+       "io/fs"
        "log"
        "net/http"
        "os"
@@ -159,6 +160,18 @@ type FileSystem interface {
        MemorySize() int64
 }
 
+type fsFS struct {
+       FileSystem
+}
+
+// FS returns an fs.FS interface to the given FileSystem, to enable
+// the use of fs.WalkDir, etc.
+func FS(fs FileSystem) fs.FS { return fsFS{fs} }
+func (fs fsFS) Open(path string) (fs.File, error) {
+       f, err := fs.FileSystem.Open(path)
+       return f, err
+}
+
 type inode interface {
        SetParent(parent inode, name string)
        Parent() inode

diff --git a/sdk/go/arvados/fs_filehandle.go b/sdk/go/arvados/fs_filehandle.go
index 4530a7b06a4d58231f2b4d95287ee792c977431a..f50dd4612b1385f74de6c8de205b29dd01c622ec 100644 (file)
--- a/sdk/go/arvados/fs_filehandle.go
+++ b/sdk/go/arvados/fs_filehandle.go
@@ -6,6 +6,7 @@ package arvados
 
 import (
        "io"
+       "io/fs"
        "os"
 )
 
@@ -73,6 +74,31 @@ func (f *filehandle) Write(p []byte) (n int, err error) {
        return
 }
 
+// dirEntry implements fs.DirEntry, see (*filehandle)ReadDir().
+type dirEntry struct {
+       os.FileInfo
+}
+
+func (ent dirEntry) Type() fs.FileMode {
+       return ent.Mode().Type()
+}
+func (ent dirEntry) Info() (fs.FileInfo, error) {
+       return ent, nil
+}
+
+// ReadDir implements fs.ReadDirFile.
+func (f *filehandle) ReadDir(count int) ([]fs.DirEntry, error) {
+       fis, err := f.Readdir(count)
+       if len(fis) == 0 {
+               return nil, err
+       }
+       ents := make([]fs.DirEntry, len(fis))
+       for i, fi := range fis {
+               ents[i] = dirEntry{fi}
+       }
+       return ents, err
+}
+
 func (f *filehandle) Readdir(count int) ([]os.FileInfo, error) {
        if !f.inode.IsDir() {
                return nil, ErrInvalidOperation