vendor: add github.com/hanwen/go-fuse/v2@master for mount2

vendor/github.com/hanwen/go-fuse/v2/fuse/direntry.go

@@ -0,0 +1,118 @@
+// Copyright 2016 the Go-FUSE 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 fuse
+
+// all of the code for DirEntryList.
+
+import (
+	"fmt"
+	"unsafe"
+)
+
+var eightPadding [8]byte
+
+const direntSize = int(unsafe.Sizeof(_Dirent{}))
+
+// DirEntry is a type for PathFileSystem and NodeFileSystem to return
+// directory contents in.
+type DirEntry struct {
+	// Mode is the file's mode. Only the high bits (eg. S_IFDIR)
+	// are considered.
+	Mode uint32
+
+	// Name is the basename of the file in the directory.
+	Name string
+
+	// Ino is the inode number.
+	Ino uint64
+}
+
+func (d DirEntry) String() string {
+	return fmt.Sprintf("%o: %q ino=%d", d.Mode, d.Name, d.Ino)
+}
+
+// DirEntryList holds the return value for READDIR and READDIRPLUS
+// opcodes.
+type DirEntryList struct {
+	buf    []byte
+	size   int
+	offset uint64
+}
+
+// NewDirEntryList creates a DirEntryList with the given data buffer
+// and offset.
+func NewDirEntryList(data []byte, off uint64) *DirEntryList {
+	return &DirEntryList{
+		buf:    data[:0],
+		size:   len(data),
+		offset: off,
+	}
+}
+
+// AddDirEntry tries to add an entry, and reports whether it
+// succeeded.
+func (l *DirEntryList) AddDirEntry(e DirEntry) bool {
+	return l.Add(0, e.Name, e.Ino, e.Mode)
+}
+
+// Add adds a direntry to the DirEntryList, returning whether it
+// succeeded.
+func (l *DirEntryList) Add(prefix int, name string, inode uint64, mode uint32) bool {
+	if inode == 0 {
+		inode = FUSE_UNKNOWN_INO
+	}
+	padding := (8 - len(name)&7) & 7
+	delta := padding + direntSize + len(name) + prefix
+	oldLen := len(l.buf)
+	newLen := delta + oldLen
+
+	if newLen > l.size {
+		return false
+	}
+	l.buf = l.buf[:newLen]
+	oldLen += prefix
+	dirent := (*_Dirent)(unsafe.Pointer(&l.buf[oldLen]))
+	dirent.Off = l.offset + 1
+	dirent.Ino = inode
+	dirent.NameLen = uint32(len(name))
+	dirent.Typ = (mode & 0170000) >> 12
+	oldLen += direntSize
+	copy(l.buf[oldLen:], name)
+	oldLen += len(name)
+
+	if padding > 0 {
+		copy(l.buf[oldLen:], eightPadding[:padding])
+	}
+
+	l.offset = dirent.Off
+	return true
+}
+
+// AddDirLookupEntry is used for ReadDirPlus. It serializes a DirEntry
+// and returns the space for entry. If no space is left, returns a nil
+// pointer.
+func (l *DirEntryList) AddDirLookupEntry(e DirEntry) *EntryOut {
+	lastStart := len(l.buf)
+	ok := l.Add(int(unsafe.Sizeof(EntryOut{})), e.Name,
+		e.Ino, e.Mode)
+	if !ok {
+		return nil
+	}
+	result := (*EntryOut)(unsafe.Pointer(&l.buf[lastStart]))
+	*result = EntryOut{}
+	return result
+}
+
+// FixMode overrides the mode of the last direntry that was added. This can
+// be needed when a directory changes while READDIRPLUS is running.
+func (l *DirEntryList) FixMode(mode uint32) {
+	oldLen := len(l.buf) - int(unsafe.Sizeof(_Dirent{}))
+	dirent := (*_Dirent)(unsafe.Pointer(&l.buf[oldLen]))
+	dirent.Typ = (mode & 0170000) >> 12
+}
+
+func (l *DirEntryList) bytes() []byte {
+	return l.buf
+}