mirror of
https://github.com/gohugoio/hugo.git
synced 2024-11-21 20:46:30 -05:00
103 lines
2.2 KiB
Go
103 lines
2.2 KiB
Go
// Copyright 2015 The Hugo Authors. All rights reserved.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package transform
|
|
|
|
import (
|
|
"bytes"
|
|
"io"
|
|
|
|
bp "github.com/gohugoio/hugo/bufferpool"
|
|
)
|
|
|
|
type trans func(rw contentTransformer)
|
|
|
|
type link trans
|
|
|
|
type chain []link
|
|
|
|
// NewChain creates a chained content transformer given the provided transforms.
|
|
func NewChain(trs ...link) chain {
|
|
return trs
|
|
}
|
|
|
|
// NewEmptyTransforms creates a new slice of transforms with a capacity of 20.
|
|
func NewEmptyTransforms() []link {
|
|
return make([]link, 0, 20)
|
|
}
|
|
|
|
// contentTransformer is an interface that enables rotation of pooled buffers
|
|
// in the transformer chain.
|
|
type contentTransformer interface {
|
|
Path() []byte
|
|
Content() []byte
|
|
io.Writer
|
|
}
|
|
|
|
// Implements contentTransformer
|
|
// Content is read from the from-buffer and rewritten to to the to-buffer.
|
|
type fromToBuffer struct {
|
|
path []byte
|
|
from *bytes.Buffer
|
|
to *bytes.Buffer
|
|
}
|
|
|
|
func (ft fromToBuffer) Path() []byte {
|
|
return ft.path
|
|
}
|
|
|
|
func (ft fromToBuffer) Write(p []byte) (n int, err error) {
|
|
return ft.to.Write(p)
|
|
}
|
|
|
|
func (ft fromToBuffer) Content() []byte {
|
|
return ft.from.Bytes()
|
|
}
|
|
|
|
func (c *chain) Apply(w io.Writer, r io.Reader, p []byte) error {
|
|
if len(*c) == 0 {
|
|
_, err := io.Copy(w, r)
|
|
return err
|
|
}
|
|
|
|
b1 := bp.GetBuffer()
|
|
defer bp.PutBuffer(b1)
|
|
|
|
if _, err := b1.ReadFrom(r); err != nil {
|
|
return err
|
|
}
|
|
|
|
b2 := bp.GetBuffer()
|
|
defer bp.PutBuffer(b2)
|
|
|
|
fb := &fromToBuffer{path: p, from: b1, to: b2}
|
|
|
|
for i, tr := range *c {
|
|
if i > 0 {
|
|
if fb.from == b1 {
|
|
fb.from = b2
|
|
fb.to = b1
|
|
fb.to.Reset()
|
|
} else {
|
|
fb.from = b1
|
|
fb.to = b2
|
|
fb.to.Reset()
|
|
}
|
|
}
|
|
|
|
tr(fb)
|
|
}
|
|
|
|
_, err := fb.to.WriteTo(w)
|
|
return err
|
|
}
|