summaryrefslogtreecommitdiff
path: root/src/cmd/godoc/dirtrees.go
blob: fda7adce523b3c8eb5dd20c0ad83695a4820becc (plain)
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
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
// Copyright 2010 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.

// This file contains the code dealing with package directory trees.

package main

import (
	"bytes"
	"go/doc"
	"go/parser"
	"go/token"
	"log"
	"os"
	pathpkg "path"
	"strings"
)

// Conventional name for directories containing test data.
// Excluded from directory trees.
//
const testdataDirName = "testdata"

type Directory struct {
	Depth    int
	Path     string       // directory path; includes Name
	Name     string       // directory name
	HasPkg   bool         // true if the directory contains at least one package
	Synopsis string       // package documentation, if any
	Dirs     []*Directory // subdirectories
}

func isGoFile(fi os.FileInfo) bool {
	name := fi.Name()
	return !fi.IsDir() &&
		len(name) > 0 && name[0] != '.' && // ignore .files
		pathpkg.Ext(name) == ".go"
}

func isPkgFile(fi os.FileInfo) bool {
	return isGoFile(fi) &&
		!strings.HasSuffix(fi.Name(), "_test.go") // ignore test files
}

func isPkgDir(fi os.FileInfo) bool {
	name := fi.Name()
	return fi.IsDir() && len(name) > 0 &&
		name[0] != '_' && name[0] != '.' // ignore _files and .files
}

type treeBuilder struct {
	maxDepth int
}

func (b *treeBuilder) newDirTree(fset *token.FileSet, path, name string, depth int) *Directory {
	if name == testdataDirName {
		return nil
	}

	if depth >= b.maxDepth {
		// return a dummy directory so that the parent directory
		// doesn't get discarded just because we reached the max
		// directory depth
		return &Directory{
			Depth: depth,
			Path:  path,
			Name:  name,
		}
	}

	list, _ := fs.ReadDir(path)

	// determine number of subdirectories and if there are package files
	ndirs := 0
	hasPkgFiles := false
	var synopses [3]string // prioritized package documentation (0 == highest priority)
	for _, d := range list {
		switch {
		case isPkgDir(d):
			ndirs++
		case isPkgFile(d):
			// looks like a package file, but may just be a file ending in ".go";
			// don't just count it yet (otherwise we may end up with hasPkgFiles even
			// though the directory doesn't contain any real package files - was bug)
			if synopses[0] == "" {
				// no "optimal" package synopsis yet; continue to collect synopses
				file, err := parseFile(fset, pathpkg.Join(path, d.Name()),
					parser.ParseComments|parser.PackageClauseOnly)
				if err == nil {
					hasPkgFiles = true
					if file.Doc != nil {
						// prioritize documentation
						i := -1
						switch file.Name.Name {
						case name:
							i = 0 // normal case: directory name matches package name
						case "main":
							i = 1 // directory contains a main package
						default:
							i = 2 // none of the above
						}
						if 0 <= i && i < len(synopses) && synopses[i] == "" {
							synopses[i] = doc.Synopsis(file.Doc.Text())
						}
					}
				}
			}
		}
	}

	// create subdirectory tree
	var dirs []*Directory
	if ndirs > 0 {
		dirs = make([]*Directory, ndirs)
		i := 0
		for _, d := range list {
			if isPkgDir(d) {
				name := d.Name()
				dd := b.newDirTree(fset, pathpkg.Join(path, name), name, depth+1)
				if dd != nil {
					dirs[i] = dd
					i++
				}
			}
		}
		dirs = dirs[0:i]
	}

	// if there are no package files and no subdirectories
	// containing package files, ignore the directory
	if !hasPkgFiles && len(dirs) == 0 {
		return nil
	}

	// select the highest-priority synopsis for the directory entry, if any
	synopsis := ""
	for _, synopsis = range synopses {
		if synopsis != "" {
			break
		}
	}

	return &Directory{
		Depth:    depth,
		Path:     path,
		Name:     name,
		HasPkg:   hasPkgFiles,
		Synopsis: synopsis,
		Dirs:     dirs,
	}
}

// newDirectory creates a new package directory tree with at most maxDepth
// levels, anchored at root. The result tree is pruned such that it only
// contains directories that contain package files or that contain
// subdirectories containing package files (transitively). If a non-nil
// pathFilter is provided, directory paths additionally must be accepted
// by the filter (i.e., pathFilter(path) must be true). If a value >= 0 is
// provided for maxDepth, nodes at larger depths are pruned as well; they
// are assumed to contain package files even if their contents are not known
// (i.e., in this case the tree may contain directories w/o any package files).
//
func newDirectory(root string, maxDepth int) *Directory {
	// The root could be a symbolic link so use Stat not Lstat.
	d, err := fs.Stat(root)
	// If we fail here, report detailed error messages; otherwise
	// is is hard to see why a directory tree was not built.
	switch {
	case err != nil:
		log.Printf("newDirectory(%s): %s", root, err)
		return nil
	case !isPkgDir(d):
		log.Printf("newDirectory(%s): not a package directory", root)
		return nil
	}
	if maxDepth < 0 {
		maxDepth = 1e6 // "infinity"
	}
	b := treeBuilder{maxDepth}
	// the file set provided is only for local parsing, no position
	// information escapes and thus we don't need to save the set
	return b.newDirTree(token.NewFileSet(), root, d.Name(), 0)
}

func (dir *Directory) writeLeafs(buf *bytes.Buffer) {
	if dir != nil {
		if len(dir.Dirs) == 0 {
			buf.WriteString(dir.Path)
			buf.WriteByte('\n')
			return
		}

		for _, d := range dir.Dirs {
			d.writeLeafs(buf)
		}
	}
}

func (dir *Directory) walk(c chan<- *Directory, skipRoot bool) {
	if dir != nil {
		if !skipRoot {
			c <- dir
		}
		for _, d := range dir.Dirs {
			d.walk(c, false)
		}
	}
}

func (dir *Directory) iter(skipRoot bool) <-chan *Directory {
	c := make(chan *Directory)
	go func() {
		dir.walk(c, skipRoot)
		close(c)
	}()
	return c
}

func (dir *Directory) lookupLocal(name string) *Directory {
	for _, d := range dir.Dirs {
		if d.Name == name {
			return d
		}
	}
	return nil
}

func splitPath(p string) []string {
	p = strings.TrimPrefix(p, "/")
	if p == "" {
		return nil
	}
	return strings.Split(p, "/")
}

// lookup looks for the *Directory for a given path, relative to dir.
func (dir *Directory) lookup(path string) *Directory {
	d := splitPath(dir.Path)
	p := splitPath(path)
	i := 0
	for i < len(d) {
		if i >= len(p) || d[i] != p[i] {
			return nil
		}
		i++
	}
	for dir != nil && i < len(p) {
		dir = dir.lookupLocal(p[i])
		i++
	}
	return dir
}

// DirEntry describes a directory entry. The Depth and Height values
// are useful for presenting an entry in an indented fashion.
//
type DirEntry struct {
	Depth    int    // >= 0
	Height   int    // = DirList.MaxHeight - Depth, > 0
	Path     string // directory path; includes Name, relative to DirList root
	Name     string // directory name
	HasPkg   bool   // true if the directory contains at least one package
	Synopsis string // package documentation, if any
}

type DirList struct {
	MaxHeight int // directory tree height, > 0
	List      []DirEntry
}

// listing creates a (linear) directory listing from a directory tree.
// If skipRoot is set, the root directory itself is excluded from the list.
//
func (root *Directory) listing(skipRoot bool) *DirList {
	if root == nil {
		return nil
	}

	// determine number of entries n and maximum height
	n := 0
	minDepth := 1 << 30 // infinity
	maxDepth := 0
	for d := range root.iter(skipRoot) {
		n++
		if minDepth > d.Depth {
			minDepth = d.Depth
		}
		if maxDepth < d.Depth {
			maxDepth = d.Depth
		}
	}
	maxHeight := maxDepth - minDepth + 1

	if n == 0 {
		return nil
	}

	// create list
	list := make([]DirEntry, n)
	i := 0
	for d := range root.iter(skipRoot) {
		p := &list[i]
		p.Depth = d.Depth - minDepth
		p.Height = maxHeight - p.Depth
		// the path is relative to root.Path - remove the root.Path
		// prefix (the prefix should always be present but avoid
		// crashes and check)
		path := strings.TrimPrefix(d.Path, root.Path)
		// remove leading separator if any - path must be relative
		path = strings.TrimPrefix(path, "/")
		p.Path = path
		p.Name = d.Name
		p.HasPkg = d.HasPkg
		p.Synopsis = d.Synopsis
		i++
	}

	return &DirList{maxHeight, list}
}