This file is indexed.

/usr/share/gocode/src/github.com/hanwen/go-fuse/unionfs/cachingfs.go is in golang-github-hanwen-go-fuse-dev 0.0~git20171124.0.14c3015-4.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
// 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 unionfs

import (
	"fmt"
	"log"
	"strings"
	"time"

	"github.com/hanwen/go-fuse/fuse"
	"github.com/hanwen/go-fuse/fuse/nodefs"
	"github.com/hanwen/go-fuse/fuse/pathfs"
)

const _XATTRSEP = "@XATTR@"

type attrResponse struct {
	*fuse.Attr
	fuse.Status
}

type xattrResponse struct {
	data []byte
	fuse.Status
}

type dirResponse struct {
	entries []fuse.DirEntry
	fuse.Status
}

type linkResponse struct {
	linkContent string
	fuse.Status
}

// Caches filesystem metadata.
type cachingFileSystem struct {
	pathfs.FileSystem

	attributes *TimedCache
	dirs       *TimedCache
	links      *TimedCache
	xattr      *TimedCache
}

func readDir(fs pathfs.FileSystem, name string) *dirResponse {
	origStream, code := fs.OpenDir(name, nil)

	r := &dirResponse{nil, code}
	if !code.Ok() {
		return r
	}
	r.entries = origStream
	return r
}

func getAttr(fs pathfs.FileSystem, name string) *attrResponse {
	a, code := fs.GetAttr(name, nil)
	return &attrResponse{
		Attr:   a,
		Status: code,
	}
}

func getXAttr(fs pathfs.FileSystem, nameAttr string) *xattrResponse {
	ns := strings.SplitN(nameAttr, _XATTRSEP, 2)
	a, code := fs.GetXAttr(ns[0], ns[1], nil)
	return &xattrResponse{
		data:   a,
		Status: code,
	}
}

func readLink(fs pathfs.FileSystem, name string) *linkResponse {
	a, code := fs.Readlink(name, nil)
	return &linkResponse{
		linkContent: a,
		Status:      code,
	}
}

func NewCachingFileSystem(fs pathfs.FileSystem, ttl time.Duration) pathfs.FileSystem {
	c := new(cachingFileSystem)
	c.FileSystem = fs
	c.attributes = NewTimedCache(func(n string) (interface{}, bool) {
		a := getAttr(fs, n)
		return a, a.Ok()
	}, ttl)
	c.dirs = NewTimedCache(func(n string) (interface{}, bool) {
		d := readDir(fs, n)
		return d, d.Ok()
	}, ttl)
	c.links = NewTimedCache(func(n string) (interface{}, bool) {
		l := readLink(fs, n)
		return l, l.Ok()
	}, ttl)
	c.xattr = NewTimedCache(func(n string) (interface{}, bool) {
		l := getXAttr(fs, n)
		return l, l.Ok()
	}, ttl)
	return c
}

func (fs *cachingFileSystem) DropCache() {
	for _, c := range []*TimedCache{fs.attributes, fs.dirs, fs.links, fs.xattr} {
		c.DropAll(nil)
	}
}

func (fs *cachingFileSystem) GetAttr(name string, context *fuse.Context) (*fuse.Attr, fuse.Status) {
	if name == _DROP_CACHE {
		return &fuse.Attr{
			Mode: fuse.S_IFREG | 0777,
		}, fuse.OK
	}

	r := fs.attributes.Get(name).(*attrResponse)
	return r.Attr, r.Status
}

func (fs *cachingFileSystem) GetXAttr(name string, attr string, context *fuse.Context) ([]byte, fuse.Status) {
	key := name + _XATTRSEP + attr
	r := fs.xattr.Get(key).(*xattrResponse)
	return r.data, r.Status
}

func (fs *cachingFileSystem) Readlink(name string, context *fuse.Context) (string, fuse.Status) {
	r := fs.links.Get(name).(*linkResponse)
	return r.linkContent, r.Status
}

func (fs *cachingFileSystem) OpenDir(name string, context *fuse.Context) (stream []fuse.DirEntry, status fuse.Status) {
	r := fs.dirs.Get(name).(*dirResponse)
	return r.entries, r.Status
}

func (fs *cachingFileSystem) String() string {
	return fmt.Sprintf("cachingFileSystem(%v)", fs.FileSystem)
}

func (fs *cachingFileSystem) Open(name string, flags uint32, context *fuse.Context) (f nodefs.File, status fuse.Status) {
	if flags&fuse.O_ANYWRITE != 0 && name == _DROP_CACHE {
		log.Println("Dropping cache for", fs)
		fs.DropCache()
	}
	return fs.FileSystem.Open(name, flags, context)
}