stacktracer_fs.go (2113B)
1 // Copyright 2019 The Hugo Authors. All rights reserved.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 // http://www.apache.org/licenses/LICENSE-2.0
7 //
8 // Unless required by applicable law or agreed to in writing, software
9 // distributed under the License is distributed on an "AS IS" BASIS,
10 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11 // See the License for the specific language governing permissions and
12 // limitations under the License.
13
14 package hugofs
15
16 import (
17 "fmt"
18 "os"
19 "regexp"
20 "runtime"
21
22 "github.com/gohugoio/hugo/common/types"
23
24 "github.com/spf13/afero"
25 )
26
27 var (
28 // Make sure we don't accidentally use this in the real Hugo.
29 _ types.DevMarker = (*stacktracerFs)(nil)
30 _ FilesystemUnwrapper = (*stacktracerFs)(nil)
31 )
32
33 // NewStacktracerFs wraps the given fs printing stack traces for file creates
34 // matching the given regexp pattern.
35 func NewStacktracerFs(fs afero.Fs, pattern string) afero.Fs {
36 return &stacktracerFs{Fs: fs, re: regexp.MustCompile(pattern)}
37 }
38
39 // stacktracerFs can be used in hard-to-debug development situations where
40 // you get some input you don't understand where comes from.
41 type stacktracerFs struct {
42 afero.Fs
43
44 // Will print stacktrace for every file creates matching this pattern.
45 re *regexp.Regexp
46 }
47
48 func (fs *stacktracerFs) DevOnly() {
49 }
50
51 func (fs *stacktracerFs) UnwrapFilesystem() afero.Fs {
52 return fs.Fs
53 }
54
55 func (fs *stacktracerFs) onCreate(filename string) {
56 if fs.re.MatchString(filename) {
57 trace := make([]byte, 1500)
58 runtime.Stack(trace, true)
59 fmt.Printf("\n===========\n%q:\n%s\n", filename, trace)
60 }
61 }
62
63 func (fs *stacktracerFs) Create(name string) (afero.File, error) {
64 f, err := fs.Fs.Create(name)
65 if err == nil {
66 fs.onCreate(name)
67 }
68 return f, err
69 }
70
71 func (fs *stacktracerFs) OpenFile(name string, flag int, perm os.FileMode) (afero.File, error) {
72 f, err := fs.Fs.OpenFile(name, flag, perm)
73 if err == nil && isWrite(flag) {
74 fs.onCreate(name)
75 }
76 return f, err
77 }