1 files changed, 130 insertions, 0 deletions
diff --git a/fs/memory.go b/fs/memory.go
new file mode 100644
index 0000000..5f5d327
--- /dev/null
+++ b/fs/memory.go
@@ -0,0 +1,130 @@
+package fs
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"time"
+)
+
+type memfsBase struct {
+	parent *memfsDir
+	name   string
+	exec   bool
+	mtime  time.Time
+}
+
+func (b memfsBase) Name() string       { return b.name }
+func (b memfsBase) Executable() bool   { return b.exec }
+func (b memfsBase) ModTime() time.Time { return b.mtime }
+
+func (b memfsBase) Delete() error {
+	if b.parent == nil {
+		return errors.New("Root entry can not be deleted")
+	}
+	b.parent.deleteChild(b.name)
+	return nil
+}
+
+type memfsFile struct {
+	memfsBase
+	content *bytes.Buffer
+}
+
+func (memfsFile) Type() FileType { return FFile }
+
+func (f memfsFile) Open() (io.ReadWriteCloser, error) {
+	return f, nil
+}
+
+func (f memfsFile) Read(p []byte) (int, error) {
+	return f.content.Read(p)
+}
+
+func (f memfsFile) Write(p []byte) (int, error) {
+	return f.content.Write(p)
+}
+
+func (memfsBase) Close() error {
+	return nil
+}
+
+type memfsDir struct {
+	memfsBase
+	children map[string]File
+}
+
+func (memfsDir) Type() FileType { return FDir }
+
+func (d memfsDir) Readdir() ([]File, error) {
+	l := make([]File, 0, len(d.children))
+
+	for _, f := range d.children {
+		l = append(l, f)
+	}
+
+	return l, nil
+}
+
+func (d memfsDir) createChildBase(name string, exec bool) memfsBase {
+	return memfsBase{
+		parent: &d,
+		name:   name,
+		exec:   exec,
+		mtime:  time.Now(),
+	}
+}
+
+func (d memfsDir) CreateChildFile(name string, exec bool) (RegularFile, error) {
+	child := memfsFile{
+		memfsBase: d.createChildBase(name, exec),
+		content:   new(bytes.Buffer),
+	}
+	d.children[name] = child
+	return child, nil
+}
+
+func (d memfsDir) CreateChildDir(name string) (Dir, error) {
+	child := memfsDir{
+		memfsBase: d.createChildBase(name, true),
+		children:  make(map[string]File),
+	}
+	d.children[name] = child
+	return child, nil
+}
+
+func (d memfsDir) CreateChildSymlink(name string, target string) (Symlink, error) {
+	child := memfsSymlink{
+		memfsBase: d.createChildBase(name, false),
+		target:    target,
+	}
+	d.children[name] = child
+	return child, nil
+}
+
+func (d *memfsDir) deleteChild(name string) {
+	delete(d.children, name)
+}
+
+func NewMemoryFSRoot(name string) Dir {
+	return memfsDir{
+		memfsBase: memfsBase{
+			parent: nil,
+			name:   name,
+			exec:   true,
+			mtime:  time.Now(),
+		},
+		children: make(map[string]File),
+	}
+}
+
+type memfsSymlink struct {
+	memfsBase
+	target string
+}
+
+func (memfsSymlink) Type() FileType { return FSymlink }
+
+func (s memfsSymlink) Readlink() (string, error) {
+	return s.target, nil
+}