github.com/anakojm/hugo-katex@v0.0.0-20231023141351-42d6f5de9c0b/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  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  }