github.com/neohugo/neohugo@v0.123.8/tpl/images/images.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 images provides template functions for manipulating images.
    15  package images
    16  
    17  import (
    18  	"errors"
    19  	"image"
    20  	"sync"
    21  
    22  	"github.com/bep/overlayfs"
    23  	"github.com/neohugo/neohugo/resources/images"
    24  
    25  	// Importing image codecs for image.DecodeConfig
    26  	_ "image/gif"
    27  	_ "image/jpeg"
    28  	_ "image/png"
    29  
    30  	// Import webp codec
    31  	_ "golang.org/x/image/webp"
    32  
    33  	"github.com/neohugo/neohugo/deps"
    34  	"github.com/spf13/afero"
    35  	"github.com/spf13/cast"
    36  )
    37  
    38  // New returns a new instance of the images-namespaced template functions.
    39  func New(d *deps.Deps) *Namespace {
    40  	var readFileFs afero.Fs
    41  
    42  	// The docshelper script does not have or need all the dependencies set up.
    43  	if d.PathSpec != nil {
    44  		readFileFs = overlayfs.New(overlayfs.Options{
    45  			Fss: []afero.Fs{
    46  				d.PathSpec.BaseFs.Work,
    47  				d.PathSpec.BaseFs.Content.Fs,
    48  			},
    49  		})
    50  	}
    51  
    52  	return &Namespace{
    53  		readFileFs: readFileFs,
    54  		Filters:    &images.Filters{},
    55  		cache:      map[string]image.Config{},
    56  		deps:       d,
    57  	}
    58  }
    59  
    60  // Namespace provides template functions for the "images" namespace.
    61  type Namespace struct {
    62  	*images.Filters
    63  	readFileFs afero.Fs
    64  	cacheMu    sync.RWMutex
    65  	cache      map[string]image.Config
    66  
    67  	deps *deps.Deps
    68  }
    69  
    70  // Config returns the image.Config for the specified path relative to the
    71  // working directory.
    72  func (ns *Namespace) Config(path any) (image.Config, error) {
    73  	filename, err := cast.ToStringE(path)
    74  	if err != nil {
    75  		return image.Config{}, err
    76  	}
    77  
    78  	if filename == "" {
    79  		return image.Config{}, errors.New("config needs a filename")
    80  	}
    81  
    82  	// Check cache for image config.
    83  	ns.cacheMu.RLock()
    84  	config, ok := ns.cache[filename]
    85  	ns.cacheMu.RUnlock()
    86  
    87  	if ok {
    88  		return config, nil
    89  	}
    90  
    91  	f, err := ns.readFileFs.Open(filename)
    92  	if err != nil {
    93  		return image.Config{}, err
    94  	}
    95  	defer f.Close()
    96  
    97  	config, _, err = image.DecodeConfig(f)
    98  	if err != nil {
    99  		return config, err
   100  	}
   101  
   102  	ns.cacheMu.Lock()
   103  	ns.cache[filename] = config
   104  	ns.cacheMu.Unlock()
   105  
   106  	return config, nil
   107  }
   108  
   109  // Filter applies the given filters to the image given as the last element in args.
   110  func (ns *Namespace) Filter(args ...any) (images.ImageResource, error) {
   111  	if len(args) < 2 {
   112  		return nil, errors.New("must provide an image and one or more filters")
   113  	}
   114  
   115  	img := args[len(args)-1].(images.ImageResource)
   116  	filtersv := args[:len(args)-1]
   117  
   118  	return img.Filter(filtersv...)
   119  }