key.go (1734B)
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 internal
15
16 import "github.com/gohugoio/hugo/helpers"
17
18 // ResourceTransformationKey are provided by the different transformation implementations.
19 // It identifies the transformation (name) and its configuration (elements).
20 // We combine this in a chain with the rest of the transformations
21 // with the target filename and a content hash of the origin to use as cache key.
22 type ResourceTransformationKey struct {
23 Name string
24 elements []any
25 }
26
27 // NewResourceTransformationKey creates a new ResourceTransformationKey from the transformation
28 // name and elements. We will create a 64 bit FNV hash from the elements, which when combined
29 // with the other key elements should be unique for all practical applications.
30 func NewResourceTransformationKey(name string, elements ...any) ResourceTransformationKey {
31 return ResourceTransformationKey{Name: name, elements: elements}
32 }
33
34 // Value returns the Key as a string.
35 // Do not change this without good reasons.
36 func (k ResourceTransformationKey) Value() string {
37 if len(k.elements) == 0 {
38 return k.Name
39 }
40
41 return k.Name + "_" + helpers.HashString(k.elements...)
42 }