github.com/kovansky/hugo@v0.92.3-0.20220224232819-63076e4ff19f/hugofs/stacktracer_fs.go (about)

     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  // Make sure we don't accidentally use this in the real Hugo.
    28  var _ types.DevMarker = (*stacktracerFs)(nil)
    29  
    30  // NewStacktracerFs wraps the given fs printing stack traces for file creates
    31  // matching the given regexp pattern.
    32  func NewStacktracerFs(fs afero.Fs, pattern string) afero.Fs {
    33  	return &stacktracerFs{Fs: fs, re: regexp.MustCompile(pattern)}
    34  }
    35  
    36  // stacktracerFs can be used in hard-to-debug development situations where
    37  // you get some input you don't understand where comes from.
    38  type stacktracerFs struct {
    39  	afero.Fs
    40  
    41  	// Will print stacktrace for every file creates matching this pattern.
    42  	re *regexp.Regexp
    43  }
    44  
    45  func (fs *stacktracerFs) DevOnly() {
    46  }
    47  
    48  func (fs *stacktracerFs) onCreate(filename string) {
    49  	if fs.re.MatchString(filename) {
    50  		trace := make([]byte, 1500)
    51  		runtime.Stack(trace, true)
    52  		fmt.Printf("\n===========\n%q:\n%s\n", filename, trace)
    53  	}
    54  }
    55  
    56  func (fs *stacktracerFs) Create(name string) (afero.File, error) {
    57  	f, err := fs.Fs.Create(name)
    58  	if err == nil {
    59  		fs.onCreate(name)
    60  	}
    61  	return f, err
    62  }
    63  
    64  func (fs *stacktracerFs) OpenFile(name string, flag int, perm os.FileMode) (afero.File, error) {
    65  	f, err := fs.Fs.OpenFile(name, flag, perm)
    66  	if err == nil && isWrite(flag) {
    67  		fs.onCreate(name)
    68  	}
    69  	return f, err
    70  }