qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-11-18 08:44:43 -07:00
Code Releases Activity

go.tools/godoc: move vfs code to vfs package

Browse Source 
R=bradfitz
CC=golang-dev
https://golang.org/cl/11414043
This commit is contained in:
Andrew Gerrand 2013-07-17 15:02:27 +10:00
parent 7526441b70
commit 5ff0687cc9
8 changed files with 571 additions and 529 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

518
cmd/godoc/filesystem.go
View File

@ -9,16 +9,7 @@
package main
import (
"fmt"
"io"
"io/ioutil"
"net/http"
"os"
pathpkg "path"
"path/filepath"
"sort"
"strings"
"time"
"code.google.com/p/go.tools/godoc/vfs"
)
@ -36,32 +27,18 @@ import (
// of the name space and then bind any GOPATH/src directories
// on top of /src/pkg, so that all sources are in /src/pkg.
//
// For more about name spaces, see the nameSpace type's
// documentation below.
// For more about name spaces, see the NameSpace type's
// documentation in code.google.com/p/go.tools/godoc/vfs.
//
// The use of this virtual file system means that most code processing
// paths can assume they are slash-separated and should be using
// package path (often imported as pathpkg) to manipulate them,
// even on Windows.
//
var fs = nameSpace{} // the underlying file system for godoc
// Setting debugNS = true will enable debugging prints about
// name space translations.
const debugNS = false
// The FileSystem interface specifies the methods godoc is using
// to access the file system for which it serves documentation.
type FileSystem interface {
Open(path string) (vfs.ReadSeekCloser, error)
Lstat(path string) (os.FileInfo, error)
Stat(path string) (os.FileInfo, error)
ReadDir(path string) ([]os.FileInfo, error)
String() string
}
var fs = vfs.NameSpace{} // the underlying file system for godoc
// ReadFile reads the file named by path from fs and returns the contents.
func ReadFile(fs FileSystem, path string) ([]byte, error) {
func ReadFile(fs vfs.FileSystem, path string) ([]byte, error) {
rc, err := fs.Open(path)
if err != nil {
return nil, err
@ -69,490 +46,3 @@ func ReadFile(fs FileSystem, path string) ([]byte, error) {
defer rc.Close()
return ioutil.ReadAll(rc)
}
// OS returns an implementation of FileSystem reading from the
// tree rooted at root. Recording a root is convenient everywhere
// but necessary on Windows, because the slash-separated path
// passed to Open has no way to specify a drive letter. Using a root
// lets code refer to OS(`c:\`), OS(`d:\`) and so on.
func OS(root string) FileSystem {
return osFS(root)
}
type osFS string
func (root osFS) String() string { return "os(" + string(root) + ")" }
func (root osFS) resolve(path string) string {
// Clean the path so that it cannot possibly begin with ../.
// If it did, the result of filepath.Join would be outside the
// tree rooted at root. We probably won't ever see a path
// with .. in it, but be safe anyway.
path = pathpkg.Clean("/" + path)
return filepath.Join(string(root), path)
}
func (root osFS) Open(path string) (vfs.ReadSeekCloser, error) {
f, err := os.Open(root.resolve(path))
if err != nil {
return nil, err
}
fi, err := f.Stat()
if err != nil {
return nil, err
}
if fi.IsDir() {
return nil, fmt.Errorf("Open: %s is a directory", path)
}
return f, nil
}
func (root osFS) Lstat(path string) (os.FileInfo, error) {
return os.Lstat(root.resolve(path))
}
func (root osFS) Stat(path string) (os.FileInfo, error) {
return os.Stat(root.resolve(path))
}
func (root osFS) ReadDir(path string) ([]os.FileInfo, error) {
return ioutil.ReadDir(root.resolve(path)) // is sorted
}
// hasPathPrefix returns true if x == y or x == y + "/" + more
func hasPathPrefix(x, y string) bool {
return x == y || strings.HasPrefix(x, y) && (strings.HasSuffix(y, "/") || strings.HasPrefix(x[len(y):], "/"))
}
// A nameSpace is a file system made up of other file systems
// mounted at specific locations in the name space.
//
// The representation is a map from mount point locations
// to the list of file systems mounted at that location. A traditional
// Unix mount table would use a single file system per mount point,
// but we want to be able to mount multiple file systems on a single
// mount point and have the system behave as if the union of those
// file systems were present at the mount point.
// For example, if the OS file system has a Go installation in
// c:\Go and additional Go path trees in d:\Work1 and d:\Work2, then
// this name space creates the view we want for the godoc server:
//
// nameSpace{
// "/": {
// {old: "/", fs: OS(`c:\Go`), new: "/"},
// },
// "/src/pkg": {
// {old: "/src/pkg", fs: OS(`c:\Go`), new: "/src/pkg"},
// {old: "/src/pkg", fs: OS(`d:\Work1`), new: "/src"},
// {old: "/src/pkg", fs: OS(`d:\Work2`), new: "/src"},
// },
// }
//
// This is created by executing:
//
// ns := nameSpace{}
// ns.Bind("/", OS(`c:\Go`), "/", bindReplace)
// ns.Bind("/src/pkg", OS(`d:\Work1`), "/src", bindAfter)
// ns.Bind("/src/pkg", OS(`d:\Work2`), "/src", bindAfter)
//
// A particular mount point entry is a triple (old, fs, new), meaning that to
// operate on a path beginning with old, replace that prefix (old) with new
// and then pass that path to the FileSystem implementation fs.
//
// Given this name space, a ReadDir of /src/pkg/code will check each prefix
// of the path for a mount point (first /src/pkg/code, then /src/pkg, then /src,
// then /), stopping when it finds one. For the above example, /src/pkg/code
// will find the mount point at /src/pkg:
//
// {old: "/src/pkg", fs: OS(`c:\Go`), new: "/src/pkg"},
// {old: "/src/pkg", fs: OS(`d:\Work1`), new: "/src"},
// {old: "/src/pkg", fs: OS(`d:\Work2`), new: "/src"},
//
// ReadDir will when execute these three calls and merge the results:
//
// OS(`c:\Go`).ReadDir("/src/pkg/code")
// OS(`d:\Work1').ReadDir("/src/code")
// OS(`d:\Work2').ReadDir("/src/code")
//
// Note that the "/src/pkg" in "/src/pkg/code" has been replaced by
// just "/src" in the final two calls.
//
// OS is itself an implementation of a file system: it implements
// OS(`c:\Go`).ReadDir("/src/pkg/code") as ioutil.ReadDir(`c:\Go\src\pkg\code`).
//
// Because the new path is evaluated by fs (here OS(root)), another way
// to read the mount table is to mentally combine fs+new, so that this table:
//
// {old: "/src/pkg", fs: OS(`c:\Go`), new: "/src/pkg"},
// {old: "/src/pkg", fs: OS(`d:\Work1`), new: "/src"},
// {old: "/src/pkg", fs: OS(`d:\Work2`), new: "/src"},
//
// reads as:
//
// "/src/pkg" -> c:\Go\src\pkg
// "/src/pkg" -> d:\Work1\src
// "/src/pkg" -> d:\Work2\src
//
// An invariant (a redundancy) of the name space representation is that
// ns[mtpt][i].old is always equal to mtpt (in the example, ns["/src/pkg"]'s
// mount table entries always have old == "/src/pkg"). The 'old' field is
// useful to callers, because they receive just a []mountedFS and not any
// other indication of which mount point was found.
//
type nameSpace map[string][]mountedFS
// A mountedFS handles requests for path by replacing
// a prefix 'old' with 'new' and then calling the fs methods.
type mountedFS struct {
old string
fs FileSystem
new string
}
// translate translates path for use in m, replacing old with new.
//
// mountedFS{"/src/pkg", fs, "/src"}.translate("/src/pkg/code") == "/src/code".
func (m mountedFS) translate(path string) string {
path = pathpkg.Clean("/" + path)
if !hasPathPrefix(path, m.old) {
panic("translate " + path + " but old=" + m.old)
}
return pathpkg.Join(m.new, path[len(m.old):])
}
func (nameSpace) String() string {
return "ns"
}
// Fprint writes a text representation of the name space to w.
func (ns nameSpace) Fprint(w io.Writer) {
fmt.Fprint(w, "name space {\n")
var all []string
for mtpt := range ns {
all = append(all, mtpt)
}
sort.Strings(all)
for _, mtpt := range all {
fmt.Fprintf(w, "\t%s:\n", mtpt)
for _, m := range ns[mtpt] {
fmt.Fprintf(w, "\t\t%s %s\n", m.fs, m.new)
}
}
fmt.Fprint(w, "}\n")
}
// clean returns a cleaned, rooted path for evaluation.
// It canonicalizes the path so that we can use string operations
// to analyze it.
func (nameSpace) clean(path string) string {
return pathpkg.Clean("/" + path)
}
// Bind causes references to old to redirect to the path new in newfs.
// If mode is bindReplace, old redirections are discarded.
// If mode is bindBefore, this redirection takes priority over existing ones,
// but earlier ones are still consulted for paths that do not exist in newfs.
// If mode is bindAfter, this redirection happens only after existing ones
// have been tried and failed.
const (
bindReplace = iota
bindBefore
bindAfter
)
func (ns nameSpace) Bind(old string, newfs FileSystem, new string, mode int) {
old = ns.clean(old)
new = ns.clean(new)
m := mountedFS{old, newfs, new}
var mtpt []mountedFS
switch mode {
case bindReplace:
mtpt = append(mtpt, m)
case bindAfter:
mtpt = append(mtpt, ns.resolve(old)...)
mtpt = append(mtpt, m)
case bindBefore:
mtpt = append(mtpt, m)
mtpt = append(mtpt, ns.resolve(old)...)
}
// Extend m.old, m.new in inherited mount point entries.
for i := range mtpt {
m := &mtpt[i]
if m.old != old {
if !hasPathPrefix(old, m.old) {
// This should not happen. If it does, panic so
// that we can see the call trace that led to it.
panic(fmt.Sprintf("invalid Bind: old=%q m={%q, %s, %q}", old, m.old, m.fs.String(), m.new))
}
suffix := old[len(m.old):]
m.old = pathpkg.Join(m.old, suffix)
m.new = pathpkg.Join(m.new, suffix)
}
}
ns[old] = mtpt
}
// resolve resolves a path to the list of mountedFS to use for path.
func (ns nameSpace) resolve(path string) []mountedFS {
path = ns.clean(path)
for {
if m := ns[path]; m != nil {
if debugNS {
fmt.Printf("resolve %s: %v\n", path, m)
}
return m
}
if path == "/" {
break
}
path = pathpkg.Dir(path)
}
return nil
}
// Open implements the FileSystem Open method.
func (ns nameSpace) Open(path string) (vfs.ReadSeekCloser, error) {
var err error
for _, m := range ns.resolve(path) {
if debugNS {
fmt.Printf("tx %s: %v\n", path, m.translate(path))
}
r, err1 := m.fs.Open(m.translate(path))
if err1 == nil {
return r, nil
}
if err == nil {
err = err1
}
}
if err == nil {
err = &os.PathError{Op: "open", Path: path, Err: os.ErrNotExist}
}
return nil, err
}
// stat implements the FileSystem Stat and Lstat methods.
func (ns nameSpace) stat(path string, f func(FileSystem, string) (os.FileInfo, error)) (os.FileInfo, error) {
var err error
for _, m := range ns.resolve(path) {
fi, err1 := f(m.fs, m.translate(path))
if err1 == nil {
return fi, nil
}
if err == nil {
err = err1
}
}
if err == nil {
err = &os.PathError{Op: "stat", Path: path, Err: os.ErrNotExist}
}
return nil, err
}
func (ns nameSpace) Stat(path string) (os.FileInfo, error) {
return ns.stat(path, FileSystem.Stat)
}
func (ns nameSpace) Lstat(path string) (os.FileInfo, error) {
return ns.stat(path, FileSystem.Lstat)
}
// dirInfo is a trivial implementation of os.FileInfo for a directory.
type dirInfo string
func (d dirInfo) Name() string { return string(d) }
func (d dirInfo) Size() int64 { return 0 }
func (d dirInfo) Mode() os.FileMode { return os.ModeDir | 0555 }
func (d dirInfo) ModTime() time.Time { return startTime }
func (d dirInfo) IsDir() bool { return true }
func (d dirInfo) Sys() interface{} { return nil }
var startTime = time.Now()
// ReadDir implements the FileSystem ReadDir method. It's where most of the magic is.
// (The rest is in resolve.)
//
// Logically, ReadDir must return the union of all the directories that are named
// by path. In order to avoid misinterpreting Go packages, of all the directories
// that contain Go source code, we only include the files from the first,
// but we include subdirectories from all.
//
// ReadDir must also return directory entries needed to reach mount points.
// If the name space looks like the example in the type nameSpace comment,
// but c:\Go does not have a src/pkg subdirectory, we still want to be able
// to find that subdirectory, because we've mounted d:\Work1 and d:\Work2
// there. So if we don't see "src" in the directory listing for c:\Go, we add an
// entry for it before returning.
//
func (ns nameSpace) ReadDir(path string) ([]os.FileInfo, error) {
path = ns.clean(path)
var (
haveGo = false
haveName = map[string]bool{}
all []os.FileInfo
err error
first []os.FileInfo
)
for _, m := range ns.resolve(path) {
dir, err1 := m.fs.ReadDir(m.translate(path))
if err1 != nil {
if err == nil {
err = err1
}
continue
}
if dir == nil {
dir = []os.FileInfo{}
}
if first == nil {
first = dir
}
// If we don't yet have Go files in 'all' and this directory
// has some, add all the files from this directory.
// Otherwise, only add subdirectories.
useFiles := false
if !haveGo {
for _, d := range dir {
if strings.HasSuffix(d.Name(), ".go") {
useFiles = true
haveGo = true
break
}
}
}
for _, d := range dir {
name := d.Name()
if (d.IsDir() || useFiles) && !haveName[name] {
haveName[name] = true
all = append(all, d)
}
}
}
// We didn't find any directories containing Go files.
// If some directory returned successfully, use that.
if !haveGo {
for _, d := range first {
if !haveName[d.Name()] {
haveName[d.Name()] = true
all = append(all, d)
}
}
}
// Built union. Add any missing directories needed to reach mount points.
for old := range ns {
if hasPathPrefix(old, path) && old != path {
// Find next element after path in old.
elem := old[len(path):]
elem = strings.TrimPrefix(elem, "/")
if i := strings.Index(elem, "/"); i >= 0 {
elem = elem[:i]
}
if !haveName[elem] {
haveName[elem] = true
all = append(all, dirInfo(elem))
}
}
}
if len(all) == 0 {
return nil, err
}
sort.Sort(byName(all))
return all, nil
}
// byName implements sort.Interface.
type byName []os.FileInfo
func (f byName) Len() int { return len(f) }
func (f byName) Less(i, j int) bool { return f[i].Name() < f[j].Name() }
func (f byName) Swap(i, j int) { f[i], f[j] = f[j], f[i] }
// An httpFS implements http.FileSystem using a FileSystem.
type httpFS struct {
fs FileSystem
}
func (h *httpFS) Open(name string) (http.File, error) {
fi, err := h.fs.Stat(name)
if err != nil {
return nil, err
}
if fi.IsDir() {
return &httpDir{h.fs, name, nil}, nil
}
f, err := h.fs.Open(name)
if err != nil {
return nil, err
}
return &httpFile{h.fs, f, name}, nil
}
// httpDir implements http.File for a directory in a FileSystem.
type httpDir struct {
fs FileSystem
name string
pending []os.FileInfo
}
func (h *httpDir) Close() error { return nil }
func (h *httpDir) Stat() (os.FileInfo, error) { return h.fs.Stat(h.name) }
func (h *httpDir) Read([]byte) (int, error) {
return 0, fmt.Errorf("cannot Read from directory %s", h.name)
}
func (h *httpDir) Seek(offset int64, whence int) (int64, error) {
if offset == 0 && whence == 0 {
h.pending = nil
return 0, nil
}
return 0, fmt.Errorf("unsupported Seek in directory %s", h.name)
}
func (h *httpDir) Readdir(count int) ([]os.FileInfo, error) {
if h.pending == nil {
d, err := h.fs.ReadDir(h.name)
if err != nil {
return nil, err
}
if d == nil {
d = []os.FileInfo{} // not nil
}
h.pending = d
}
if len(h.pending) == 0 && count > 0 {
return nil, io.EOF
}
if count <= 0 || count > len(h.pending) {
count = len(h.pending)
}
d := h.pending[:count]
h.pending = h.pending[count:]
return d, nil
}
// httpFile implements http.File for a file (not directory) in a FileSystem.
type httpFile struct {
fs FileSystem
vfs.ReadSeekCloser
name string
}
func (h *httpFile) Stat() (os.FileInfo, error) { return h.fs.Stat(h.name) }
func (h *httpFile) Readdir(int) ([]os.FileInfo, error) {
return nil, fmt.Errorf("cannot Readdir from file %s", h.name)
}

3
cmd/godoc/godoc.go
View File

@ -34,6 +34,7 @@ import (
"unicode/utf8"
"code.google.com/p/go.tools/godoc/util"
"code.google.com/p/go.tools/godoc/vfs/httpfs"
)
// ----------------------------------------------------------------------------
@ -77,7 +78,7 @@ var (
)
func initHandlers() {
fileServer = http.FileServer(&httpFS{fs})
fileServer = http.FileServer(httpfs.New(fs))
cmdHandler = docServer{"/cmd/", "/src/cmd"}
pkgHandler = docServer{"/pkg/", "/src/pkg"}
}

17
cmd/godoc/main.go
View File

@ -48,6 +48,9 @@ import (
"regexp"
"runtime"
"strings"
"code.google.com/p/go.tools/godoc/vfs"
"code.google.com/p/go.tools/godoc/vfs/zipfs"
)
const defaultAddr = ":6060" // default webserver address
@ -172,9 +175,9 @@ func main() {
// same is true for the http handlers in initHandlers.
if *zipfile == "" {
// use file system of underlying OS
fs.Bind("/", OS(*goroot), "/", bindReplace)
fs.Bind("/", vfs.OS(*goroot), "/", vfs.BindReplace)
if *templateDir != "" {
fs.Bind("/lib/godoc", OS(*templateDir), "/", bindBefore)
fs.Bind("/lib/godoc", vfs.OS(*templateDir), "/", vfs.BindBefore)
}
} else {
// use file system specified via .zip file (path separator must be '/')
@ -183,12 +186,12 @@ func main() {
log.Fatalf("%s: %s\n", *zipfile, err)
}
defer rc.Close() // be nice (e.g., -writeIndex mode)
fs.Bind("/", NewZipFS(rc, *zipfile), *goroot, bindReplace)
fs.Bind("/", zipvfs.New(rc, *zipfile), *goroot, vfs.BindReplace)
}
// Bind $GOPATH trees into Go root.
for _, p := range filepath.SplitList(build.Default.GOPATH) {
fs.Bind("/src/pkg", OS(p), "/src", bindAfter)
fs.Bind("/src/pkg", vfs.OS(p), "/src", vfs.BindAfter)
}
readTemplates()
@ -339,18 +342,18 @@ func main() {
var forceCmd bool
var abspath, relpath string
if filepath.IsAbs(path) {
fs.Bind(target, OS(path), "/", bindReplace)
fs.Bind(target, vfs.OS(path), "/", vfs.BindReplace)
abspath = target
} else if build.IsLocalImport(path) {
cwd, _ := os.Getwd() // ignore errors
path = filepath.Join(cwd, path)
fs.Bind(target, OS(path), "/", bindReplace)
fs.Bind(target, vfs.OS(path), "/", vfs.BindReplace)
abspath = target
} else if strings.HasPrefix(path, cmdPrefix) {
path = strings.TrimPrefix(path, cmdPrefix)
forceCmd = true
} else if bp, _ := build.Import(path, "", build.FindOnly); bp.Dir != "" && bp.ImportPath != "" {
fs.Bind(target, OS(bp.Dir), "/", bindReplace)
fs.Bind(target, vfs.OS(bp.Dir), "/", vfs.BindReplace)
abspath = target
relpath = bp.ImportPath
} else {

94
godoc/vfs/httpfs/httpfs.go Normal file
View File

@ -0,0 +1,94 @@
// Copyright 2013 The Go 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 httpfs implements http.FileSystem using a godoc vfs.FileSystem.
package httpfs
import (
"fmt"
"io"
"net/http"
"os"
"code.google.com/p/go.tools/godoc/vfs"
)
func New(fs vfs.FileSystem) http.FileSystem {
return &httpFS{fs}
}
type httpFS struct {
fs vfs.FileSystem
}
func (h *httpFS) Open(name string) (http.File, error) {
fi, err := h.fs.Stat(name)
if err != nil {
return nil, err
}
if fi.IsDir() {
return &httpDir{h.fs, name, nil}, nil
}
f, err := h.fs.Open(name)
if err != nil {
return nil, err
}
return &httpFile{h.fs, f, name}, nil
}
// httpDir implements http.File for a directory in a FileSystem.
type httpDir struct {
fs vfs.FileSystem
name string
pending []os.FileInfo
}
func (h *httpDir) Close() error { return nil }
func (h *httpDir) Stat() (os.FileInfo, error) { return h.fs.Stat(h.name) }
func (h *httpDir) Read([]byte) (int, error) {
return 0, fmt.Errorf("cannot Read from directory %s", h.name)
}
func (h *httpDir) Seek(offset int64, whence int) (int64, error) {
if offset == 0 && whence == 0 {
h.pending = nil
return 0, nil
}
return 0, fmt.Errorf("unsupported Seek in directory %s", h.name)
}
func (h *httpDir) Readdir(count int) ([]os.FileInfo, error) {
if h.pending == nil {
d, err := h.fs.ReadDir(h.name)
if err != nil {
return nil, err
}
if d == nil {
d = []os.FileInfo{} // not nil
}
h.pending = d
}
if len(h.pending) == 0 && count > 0 {
return nil, io.EOF
}
if count <= 0 || count > len(h.pending) {
count = len(h.pending)
}
d := h.pending[:count]
h.pending = h.pending[count:]
return d, nil
}
// httpFile implements http.File for a file (not directory) in a FileSystem.
type httpFile struct {
fs vfs.FileSystem
vfs.ReadSeekCloser
name string
}
func (h *httpFile) Stat() (os.FileInfo, error) { return h.fs.Stat(h.name) }
func (h *httpFile) Readdir(int) ([]os.FileInfo, error) {
return nil, fmt.Errorf("cannot Readdir from file %s", h.name)
}

381
godoc/vfs/namespace.go Normal file
View File

@ -0,0 +1,381 @@
// Copyright 2011 The Go 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 vfs
import (
"fmt"
"io"
"os"
pathpkg "path"
"sort"
"strings"
"time"
)
// Setting debugNS = true will enable debugging prints about
// name space translations.
const debugNS = false
// A NameSpace is a file system made up of other file systems
// mounted at specific locations in the name space.
//
// The representation is a map from mount point locations
// to the list of file systems mounted at that location. A traditional
// Unix mount table would use a single file system per mount point,
// but we want to be able to mount multiple file systems on a single
// mount point and have the system behave as if the union of those
// file systems were present at the mount point.
// For example, if the OS file system has a Go installation in
// c:\Go and additional Go path trees in d:\Work1 and d:\Work2, then
// this name space creates the view we want for the godoc server:
//
// NameSpace{
// "/": {
// {old: "/", fs: OS(`c:\Go`), new: "/"},
// },
// "/src/pkg": {
// {old: "/src/pkg", fs: OS(`c:\Go`), new: "/src/pkg"},
// {old: "/src/pkg", fs: OS(`d:\Work1`), new: "/src"},
// {old: "/src/pkg", fs: OS(`d:\Work2`), new: "/src"},
// },
// }
//
// This is created by executing:
//
// ns := NameSpace{}
// ns.Bind("/", OS(`c:\Go`), "/", BindReplace)
// ns.Bind("/src/pkg", OS(`d:\Work1`), "/src", BindAfter)
// ns.Bind("/src/pkg", OS(`d:\Work2`), "/src", BindAfter)
//
// A particular mount point entry is a triple (old, fs, new), meaning that to
// operate on a path beginning with old, replace that prefix (old) with new
// and then pass that path to the FileSystem implementation fs.
//
// Given this name space, a ReadDir of /src/pkg/code will check each prefix
// of the path for a mount point (first /src/pkg/code, then /src/pkg, then /src,
// then /), stopping when it finds one. For the above example, /src/pkg/code
// will find the mount point at /src/pkg:
//
// {old: "/src/pkg", fs: OS(`c:\Go`), new: "/src/pkg"},
// {old: "/src/pkg", fs: OS(`d:\Work1`), new: "/src"},
// {old: "/src/pkg", fs: OS(`d:\Work2`), new: "/src"},
//
// ReadDir will when execute these three calls and merge the results:
//
// OS(`c:\Go`).ReadDir("/src/pkg/code")
// OS(`d:\Work1').ReadDir("/src/code")
// OS(`d:\Work2').ReadDir("/src/code")
//
// Note that the "/src/pkg" in "/src/pkg/code" has been replaced by
// just "/src" in the final two calls.
//
// OS is itself an implementation of a file system: it implements
// OS(`c:\Go`).ReadDir("/src/pkg/code") as ioutil.ReadDir(`c:\Go\src\pkg\code`).
//
// Because the new path is evaluated by fs (here OS(root)), another way
// to read the mount table is to mentally combine fs+new, so that this table:
//
// {old: "/src/pkg", fs: OS(`c:\Go`), new: "/src/pkg"},
// {old: "/src/pkg", fs: OS(`d:\Work1`), new: "/src"},
// {old: "/src/pkg", fs: OS(`d:\Work2`), new: "/src"},
//
// reads as:
//
// "/src/pkg" -> c:\Go\src\pkg
// "/src/pkg" -> d:\Work1\src
// "/src/pkg" -> d:\Work2\src
//
// An invariant (a redundancy) of the name space representation is that
// ns[mtpt][i].old is always equal to mtpt (in the example, ns["/src/pkg"]'s
// mount table entries always have old == "/src/pkg"). The 'old' field is
// useful to callers, because they receive just a []mountedFS and not any
// other indication of which mount point was found.
//
type NameSpace map[string][]mountedFS
// A mountedFS handles requests for path by replacing
// a prefix 'old' with 'new' and then calling the fs methods.
type mountedFS struct {
old string
fs FileSystem
new string
}
// hasPathPrefix returns true if x == y or x == y + "/" + more
func hasPathPrefix(x, y string) bool {
return x == y || strings.HasPrefix(x, y) && (strings.HasSuffix(y, "/") || strings.HasPrefix(x[len(y):], "/"))
}
// translate translates path for use in m, replacing old with new.
//
// mountedFS{"/src/pkg", fs, "/src"}.translate("/src/pkg/code") == "/src/code".
func (m mountedFS) translate(path string) string {
path = pathpkg.Clean("/" + path)
if !hasPathPrefix(path, m.old) {
panic("translate " + path + " but old=" + m.old)
}
return pathpkg.Join(m.new, path[len(m.old):])
}
func (NameSpace) String() string {
return "ns"
}
// Fprint writes a text representation of the name space to w.
func (ns NameSpace) Fprint(w io.Writer) {
fmt.Fprint(w, "name space {\n")
var all []string
for mtpt := range ns {
all = append(all, mtpt)
}
sort.Strings(all)
for _, mtpt := range all {
fmt.Fprintf(w, "\t%s:\n", mtpt)
for _, m := range ns[mtpt] {
fmt.Fprintf(w, "\t\t%s %s\n", m.fs, m.new)
}
}
fmt.Fprint(w, "}\n")
}
// clean returns a cleaned, rooted path for evaluation.
// It canonicalizes the path so that we can use string operations
// to analyze it.
func (NameSpace) clean(path string) string {
return pathpkg.Clean("/" + path)
}
type BindMode int
const (
BindReplace BindMode = iota
BindBefore
BindAfter
)
// Bind causes references to old to redirect to the path new in newfs.
// If mode is BindReplace, old redirections are discarded.
// If mode is BindBefore, this redirection takes priority over existing ones,
// but earlier ones are still consulted for paths that do not exist in newfs.
// If mode is BindAfter, this redirection happens only after existing ones
// have been tried and failed.
func (ns NameSpace) Bind(old string, newfs FileSystem, new string, mode BindMode) {
old = ns.clean(old)
new = ns.clean(new)
m := mountedFS{old, newfs, new}
var mtpt []mountedFS
switch mode {
case BindReplace:
mtpt = append(mtpt, m)
case BindAfter:
mtpt = append(mtpt, ns.resolve(old)...)
mtpt = append(mtpt, m)
case BindBefore:
mtpt = append(mtpt, m)
mtpt = append(mtpt, ns.resolve(old)...)
}
// Extend m.old, m.new in inherited mount point entries.
for i := range mtpt {
m := &mtpt[i]
if m.old != old {
if !hasPathPrefix(old, m.old) {
// This should not happen. If it does, panic so
// that we can see the call trace that led to it.
panic(fmt.Sprintf("invalid Bind: old=%q m={%q, %s, %q}", old, m.old, m.fs.String(), m.new))
}
suffix := old[len(m.old):]
m.old = pathpkg.Join(m.old, suffix)
m.new = pathpkg.Join(m.new, suffix)
}
}
ns[old] = mtpt
}
// resolve resolves a path to the list of mountedFS to use for path.
func (ns NameSpace) resolve(path string) []mountedFS {
path = ns.clean(path)
for {
if m := ns[path]; m != nil {
if debugNS {
fmt.Printf("resolve %s: %v\n", path, m)
}
return m
}
if path == "/" {
break
}
path = pathpkg.Dir(path)
}
return nil
}
// Open implements the FileSystem Open method.
func (ns NameSpace) Open(path string) (ReadSeekCloser, error) {
var err error
for _, m := range ns.resolve(path) {
if debugNS {
fmt.Printf("tx %s: %v\n", path, m.translate(path))
}
r, err1 := m.fs.Open(m.translate(path))
if err1 == nil {
return r, nil
}
if err == nil {
err = err1
}
}
if err == nil {
err = &os.PathError{Op: "open", Path: path, Err: os.ErrNotExist}
}
return nil, err
}
// stat implements the FileSystem Stat and Lstat methods.
func (ns NameSpace) stat(path string, f func(FileSystem, string) (os.FileInfo, error)) (os.FileInfo, error) {
var err error
for _, m := range ns.resolve(path) {
fi, err1 := f(m.fs, m.translate(path))
if err1 == nil {
return fi, nil
}
if err == nil {
err = err1
}
}
if err == nil {
err = &os.PathError{Op: "stat", Path: path, Err: os.ErrNotExist}
}
return nil, err
}
func (ns NameSpace) Stat(path string) (os.FileInfo, error) {
return ns.stat(path, FileSystem.Stat)
}
func (ns NameSpace) Lstat(path string) (os.FileInfo, error) {
return ns.stat(path, FileSystem.Lstat)
}
// dirInfo is a trivial implementation of os.FileInfo for a directory.
type dirInfo string
func (d dirInfo) Name() string { return string(d) }
func (d dirInfo) Size() int64 { return 0 }
func (d dirInfo) Mode() os.FileMode { return os.ModeDir | 0555 }
func (d dirInfo) ModTime() time.Time { return startTime }
func (d dirInfo) IsDir() bool { return true }
func (d dirInfo) Sys() interface{} { return nil }
var startTime = time.Now()
// ReadDir implements the FileSystem ReadDir method. It's where most of the magic is.
// (The rest is in resolve.)
//
// Logically, ReadDir must return the union of all the directories that are named
// by path. In order to avoid misinterpreting Go packages, of all the directories
// that contain Go source code, we only include the files from the first,
// but we include subdirectories from all.
//
// ReadDir must also return directory entries needed to reach mount points.
// If the name space looks like the example in the type NameSpace comment,
// but c:\Go does not have a src/pkg subdirectory, we still want to be able
// to find that subdirectory, because we've mounted d:\Work1 and d:\Work2
// there. So if we don't see "src" in the directory listing for c:\Go, we add an
// entry for it before returning.
//
func (ns NameSpace) ReadDir(path string) ([]os.FileInfo, error) {
path = ns.clean(path)
var (
haveGo = false
haveName = map[string]bool{}
all []os.FileInfo
err error
first []os.FileInfo
)
for _, m := range ns.resolve(path) {
dir, err1 := m.fs.ReadDir(m.translate(path))
if err1 != nil {
if err == nil {
err = err1
}
continue
}
if dir == nil {
dir = []os.FileInfo{}
}
if first == nil {
first = dir
}
// If we don't yet have Go files in 'all' and this directory
// has some, add all the files from this directory.
// Otherwise, only add subdirectories.
useFiles := false
if !haveGo {
for _, d := range dir {
if strings.HasSuffix(d.Name(), ".go") {
useFiles = true
haveGo = true
break
}
}
}
for _, d := range dir {
name := d.Name()
if (d.IsDir() || useFiles) && !haveName[name] {
haveName[name] = true
all = append(all, d)
}
}
}
// We didn't find any directories containing Go files.
// If some directory returned successfully, use that.
if !haveGo {
for _, d := range first {
if !haveName[d.Name()] {
haveName[d.Name()] = true
all = append(all, d)
}
}
}
// Built union. Add any missing directories needed to reach mount points.
for old := range ns {
if hasPathPrefix(old, path) && old != path {
// Find next element after path in old.
elem := old[len(path):]
elem = strings.TrimPrefix(elem, "/")
if i := strings.Index(elem, "/"); i >= 0 {
elem = elem[:i]
}
if !haveName[elem] {
haveName[elem] = true
all = append(all, dirInfo(elem))
}
}
}
if len(all) == 0 {
return nil, err
}
sort.Sort(byName(all))
return all, nil
}
// byName implements sort.Interface.
type byName []os.FileInfo
func (f byName) Len() int { return len(f) }
func (f byName) Less(i, j int) bool { return f[i].Name() < f[j].Name() }
func (f byName) Swap(i, j int) { f[i], f[j] = f[j], f[i] }

63
godoc/vfs/os.go Normal file
View File

@ -0,0 +1,63 @@
// Copyright 2013 The Go 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 vfs
import (
"fmt"
"io/ioutil"
"os"
pathpkg "path"
"path/filepath"
)
// OS returns an implementation of FileSystem reading from the
// tree rooted at root. Recording a root is convenient everywhere
// but necessary on Windows, because the slash-separated path
// passed to Open has no way to specify a drive letter. Using a root
// lets code refer to OS(`c:\`), OS(`d:\`) and so on.
func OS(root string) FileSystem {
return osFS(root)
}
type osFS string
func (root osFS) String() string { return "os(" + string(root) + ")" }
func (root osFS) resolve(path string) string {
// Clean the path so that it cannot possibly begin with ../.
// If it did, the result of filepath.Join would be outside the
// tree rooted at root. We probably won't ever see a path
// with .. in it, but be safe anyway.
path = pathpkg.Clean("/" + path)
return filepath.Join(string(root), path)
}
func (root osFS) Open(path string) (ReadSeekCloser, error) {
f, err := os.Open(root.resolve(path))
if err != nil {
return nil, err
}
fi, err := f.Stat()
if err != nil {
return nil, err
}
if fi.IsDir() {
return nil, fmt.Errorf("Open: %s is a directory", path)
}
return f, nil
}
func (root osFS) Lstat(path string) (os.FileInfo, error) {
return os.Lstat(root.resolve(path))
}
func (root osFS) Stat(path string) (os.FileInfo, error) {
return os.Stat(root.resolve(path))
}
func (root osFS) ReadDir(path string) ([]os.FileInfo, error) {
return ioutil.ReadDir(root.resolve(path)) // is sorted
}

17
godoc/vfs/vfs.go
View File

@ -2,15 +2,26 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package vfs defines virtual filesystem types.
// Package vfs defines types for abstract file system access and provides an
// implementation accessing the file system of the underlying OS.
package vfs
import (
"io"
"os"
)
// Opener is a minimal virtual filesystem that can only open
// regular files.
// The FileSystem interface specifies the methods godoc is using
// to access the file system for which it serves documentation.
type FileSystem interface {
Opener
Lstat(path string) (os.FileInfo, error)
Stat(path string) (os.FileInfo, error)
ReadDir(path string) ([]os.FileInfo, error)
String() string
}
// Opener is a minimal virtual filesystem that can only open regular files.
type Opener interface {
Open(name string) (ReadSeekCloser, error)
}

7
cmd/godoc/zip.go → godoc/vfs/zipfs/zipfs.go
View File

@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This file provides an implementation of the FileSystem
// Package zipfs file provides an implementation of the FileSystem
// interface based on the contents of a .zip file.
//
// Assumptions:
@ -15,8 +15,7 @@
// like absolute paths w/o a leading '/'; i.e., the paths are considered
// relative to the root of the file system.
// - All path arguments to file system methods must be absolute paths.
package main
package zipvfs
import (
"archive/zip"
@ -190,7 +189,7 @@ func (fs *zipFS) ReadDir(abspath string) ([]os.FileInfo, error) {
return list, nil
}
func NewZipFS(rc *zip.ReadCloser, name string) FileSystem {
func New(rc *zip.ReadCloser, name string) vfs.FileSystem {
list := make(zipList, len(rc.File))
copy(list, rc.File) // sort a copy of rc.File
sort.Sort(list)