19192: Add a few bytes to MemorySize to account for data structures.

[arvados.git] / sdk / go / arvados / fs_base.go

diff --git a/sdk/go/arvados/fs_base.go b/sdk/go/arvados/fs_base.go
index 80b803729349dd500de0e7832288f593c41ab60c..ce9253ab3d4f5d5447273cfe02edca716afc52fd 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
@@ -402,7 +415,7 @@ func (n *treenode) MemorySize() (size int64) {
        for _, inode := range n.inodes {
                size += inode.MemorySize()
        }
-       return
+       return 64 + size
 }
 
 type fileSystem struct {
@@ -450,14 +463,14 @@ func (fs *fileSystem) openFile(name string, flag int, perm os.FileMode) (*fileha
        default:
                return nil, fmt.Errorf("invalid flags 0x%x", flag)
        }
-       if !writable && parent.IsDir() {
+       if parent.IsDir() {
                // A directory can be opened via "foo/", "foo/.", or
                // "foo/..".
                switch name {
                case ".", "":
-                       return &filehandle{inode: parent}, nil
+                       return &filehandle{inode: parent, readable: readable, writable: writable}, nil
                case "..":
-                       return &filehandle{inode: parent.Parent()}, nil
+                       return &filehandle{inode: parent.Parent(), readable: readable, writable: writable}, nil
                }
        }
        createMode := flag&os.O_CREATE != 0
@@ -753,7 +766,7 @@ func Splice(fs FileSystem, target string, newsubtree *Subtree) error {
                f, err = fs.OpenFile(target, os.O_CREATE|os.O_WRONLY, 0700)
        }
        if err != nil {
-               return err
+               return fmt.Errorf("open %s: %w", target, err)
        }
        defer f.Close()
        return f.Splice(newsubtree)