vendor: Add github.com/cznic/lldb and friends (new recursive dependency)

vendor/github.com/cznic/lldb/osfiler.go

@@ -0,0 +1,130 @@
+// Copyright 2014 The lldb Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lldb
+
+import (
+	"io"
+	"os"
+
+	"github.com/cznic/mathutil"
+)
+
+var _ Filer = (*OSFiler)(nil)
+
+// OSFile is an os.File like minimal set of methods allowing to construct a
+// Filer.
+type OSFile interface {
+	Name() string
+	Stat() (fi os.FileInfo, err error)
+	Sync() (err error)
+	Truncate(size int64) (err error)
+	io.Closer
+	io.Reader
+	io.ReaderAt
+	io.Seeker
+	io.Writer
+	io.WriterAt
+}
+
+// OSFiler is like a SimpleFileFiler but based on an OSFile.
+type OSFiler struct {
+	f    OSFile
+	nest int
+	size int64 // not set if < 0
+}
+
+// NewOSFiler returns a Filer from an OSFile. This Filer is like the
+// SimpleFileFiler, it does not implement the transaction related methods.
+func NewOSFiler(f OSFile) (r *OSFiler) {
+	return &OSFiler{
+		f:    f,
+		size: -1,
+	}
+}
+
+// BeginUpdate implements Filer.
+func (f *OSFiler) BeginUpdate() (err error) {
+	f.nest++
+	return nil
+}
+
+// Close implements Filer.
+func (f *OSFiler) Close() (err error) {
+	if f.nest != 0 {
+		return &ErrPERM{(f.Name() + ":Close")}
+	}
+
+	return f.f.Close()
+}
+
+// EndUpdate implements Filer.
+func (f *OSFiler) EndUpdate() (err error) {
+	if f.nest == 0 {
+		return &ErrPERM{(f.Name() + ":EndUpdate")}
+	}
+
+	f.nest--
+	return
+}
+
+// Name implements Filer.
+func (f *OSFiler) Name() string {
+	return f.f.Name()
+}
+
+// PunchHole implements Filer.
+func (f *OSFiler) PunchHole(off, size int64) (err error) {
+	return
+}
+
+// ReadAt implements Filer.
+func (f *OSFiler) ReadAt(b []byte, off int64) (n int, err error) {
+	return f.f.ReadAt(b, off)
+}
+
+// Rollback implements Filer.
+func (f *OSFiler) Rollback() (err error) { return }
+
+// Size implements Filer.
+func (f *OSFiler) Size() (n int64, err error) {
+	if f.size < 0 { // boot
+		fi, err := f.f.Stat()
+		if err != nil {
+			return 0, err
+		}
+
+		f.size = fi.Size()
+	}
+	return f.size, nil
+}
+
+// Sync implements Filer.
+func (f *OSFiler) Sync() (err error) {
+	return f.f.Sync()
+}
+
+// Truncate implements Filer.
+func (f *OSFiler) Truncate(size int64) (err error) {
+	if size < 0 {
+		return &ErrINVAL{"Truncate size", size}
+	}
+
+	f.size = size
+	return f.f.Truncate(size)
+}
+
+// WriteAt implements Filer.
+func (f *OSFiler) WriteAt(b []byte, off int64) (n int, err error) {
+	if f.size < 0 { // boot
+		fi, err := os.Stat(f.f.Name())
+		if err != nil {
+			return 0, err
+		}
+
+		f.size = fi.Size()
+	}
+	f.size = mathutil.MaxInt64(f.size, int64(len(b))+off)
+	return f.f.WriteAt(b, off)
+}