hugo/resources/resource_factories/bundler/bundler.go
2024-02-16 13:17:53 +01:00

167 lines
4.8 KiB
Go

// Copyright 2019 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 bundler contains functions for concatenation etc. of Resource objects.
package bundler
import (
"fmt"
"io"
"path"
"github.com/gohugoio/hugo/common/hugio"
"github.com/gohugoio/hugo/identity"
"github.com/gohugoio/hugo/media"
"github.com/gohugoio/hugo/resources"
"github.com/gohugoio/hugo/resources/resource"
)
// Client contains methods perform concatenation and other bundling related
// tasks to Resource objects.
type Client struct {
rs *resources.Spec
}
// New creates a new Client with the given specification.
func New(rs *resources.Spec) *Client {
return &Client{rs: rs}
}
type multiReadSeekCloser struct {
mr io.Reader
sources []hugio.ReadSeekCloser
}
func toReaders(sources []hugio.ReadSeekCloser) []io.Reader {
readers := make([]io.Reader, len(sources))
for i, r := range sources {
readers[i] = r
}
return readers
}
func newMultiReadSeekCloser(sources ...hugio.ReadSeekCloser) *multiReadSeekCloser {
mr := io.MultiReader(toReaders(sources)...)
return &multiReadSeekCloser{mr, sources}
}
func (r *multiReadSeekCloser) Read(p []byte) (n int, err error) {
return r.mr.Read(p)
}
func (r *multiReadSeekCloser) Seek(offset int64, whence int) (newOffset int64, err error) {
for _, s := range r.sources {
newOffset, err = s.Seek(offset, whence)
if err != nil {
return
}
}
r.mr = io.MultiReader(toReaders(r.sources)...)
return
}
func (r *multiReadSeekCloser) Close() error {
for _, s := range r.sources {
s.Close()
}
return nil
}
// Concat concatenates the list of Resource objects.
func (c *Client) Concat(targetPath string, r resource.Resources) (resource.Resource, error) {
targetPath = path.Clean(targetPath)
return c.rs.ResourceCache.GetOrCreate(targetPath, func() (resource.Resource, error) {
var resolvedm media.Type
// The given set of resources must be of the same Media Type.
// We may improve on that in the future, but then we need to know more.
for i, rr := range r {
if i > 0 && rr.MediaType().Type != resolvedm.Type {
return nil, fmt.Errorf("resources in Concat must be of the same Media Type, got %q and %q", rr.MediaType().Type, resolvedm.Type)
}
resolvedm = rr.MediaType()
}
idm := c.rs.Cfg.NewIdentityManager("concat")
// Add the concatenated resources as dependencies to the composite resource
// so that we can track changes to the individual resources.
idm.AddIdentityForEach(identity.ForEeachIdentityProviderFunc(
func(f func(identity.Identity) bool) bool {
var terminate bool
for _, rr := range r {
identity.WalkIdentitiesShallow(rr, func(depth int, id identity.Identity) bool {
terminate = f(id)
return terminate
})
if terminate {
break
}
}
return terminate
},
))
concatr := func() (hugio.ReadSeekCloser, error) {
var rcsources []hugio.ReadSeekCloser
for _, s := range r {
rcr, ok := s.(resource.ReadSeekCloserResource)
if !ok {
return nil, fmt.Errorf("resource %T does not implement resource.ReadSeekerCloserResource", s)
}
rc, err := rcr.ReadSeekCloser()
if err != nil {
// Close the already opened.
for _, rcs := range rcsources {
rcs.Close()
}
return nil, err
}
rcsources = append(rcsources, rc)
}
// Arbitrary JavaScript files require a barrier between them to be safely concatenated together.
// Without this, the last line of one file can affect the first line of the next file and change how both files are interpreted.
if resolvedm.MainType == media.Builtin.JavascriptType.MainType && resolvedm.SubType == media.Builtin.JavascriptType.SubType {
readers := make([]hugio.ReadSeekCloser, 2*len(rcsources)-1)
j := 0
for i := 0; i < len(rcsources); i++ {
if i > 0 {
readers[j] = hugio.NewReadSeekerNoOpCloserFromString("\n;\n")
j++
}
readers[j] = rcsources[i]
j++
}
return newMultiReadSeekCloser(readers...), nil
}
return newMultiReadSeekCloser(rcsources...), nil
}
composite, err := c.rs.NewResource(
resources.ResourceSourceDescriptor{
LazyPublish: true,
OpenReadSeekCloser: concatr,
TargetPath: targetPath,
DependencyManager: idm,
})
if err != nil {
return nil, err
}
return composite, nil
})
}