feat(blogo,renderer): built-in multirenderer support via plugin

This commit is contained in:
Guz
2025-01-13 09:31:50 -03:00
parent 40d8ae711a
commit 82e86e269a
3 changed files with 191 additions and 33 deletions

View File

@@ -142,11 +142,18 @@ func (b *Blogo) Init() error {
b.Use(&defaultSourcer{})
}
renderer := &defaultRenderer{}
log.Debug(fmt.Sprintf("Adding %q as fallback renderer", renderer.Name()))
b.Use(&defaultRenderer{})
if len(b.renderers) == 0 {
renderer := NewPlainTextRenderer()
log.Debug(
fmt.Sprintf(
"No RendererPlugin plugin found, adding %q as fallback renderer",
renderer.Name(),
),
)
b.Use(renderer)
}
fs, err := b.sources[0].Source() // TOOD: Support for multiple sources (via another plugin or built-in, with prefixes or not)
fs, err := b.sources[0].Source() // TODO: Support for multiple sources (via another plugin or built-in, with prefixes or not)
if err != nil {
return errors.Join(errors.New("failed to source files"), err)
}
@@ -156,33 +163,34 @@ func (b *Blogo) Init() error {
}
func (b *Blogo) render(src fs.File, w io.Writer) error {
for _, r := range b.renderers {
log := b.log.With(slog.String("step", "RENDERING"), slog.String("plugin", r.Name()))
log := b.log.With(slog.String("step", "RENDERING"))
log.Debug("Using renderer")
// FIX?: io.Reader can only be read once, but the plugin may need to read
// from it to know if it can even render at all, which can break the next
// plugin render method. Maybe io.ReadSeeker or io.TeeReader could solve this?
// but it would change the API away from the fs.FS API. Also, a combination of
// io.TeeReader and io.MultiReader (example: https://abdus.dev/posts/sniffing-io-reader-in-golang/#solution-io.teereader-and-io.multireader)
// could solve without changing the API, but it would use more memory for each file.
// We could also just put multi-renderer and multi-sourcer support in optional plugins.
err := r.Render(src, w)
if errors.Is(err, ErrRendererNotSupportedFile) {
log.Debug("File not supported, skipping")
continue
} else if err != nil {
log.Error("Renderer failed")
return errors.Join(fmt.Errorf("failed to render with plugin %q", r.Name()), err)
} else {
log.Debug("Successfully rendered file!")
break
}
if len(b.renderers) == 1 {
log.Debug(
"Just one renderer found, using it directly",
slog.String("plugin", b.renderers[0].Name()),
)
return b.renderers[0].Render(src, w)
}
return nil
log.Debug("Multiple renderers found, initializing built-in multi-renderer plugin")
f, t := false, true
multi := NewMultiRenderer(MultiRendererOpts{
SkipOnError: &f,
PanicOnInit: &t,
Logger: log,
})
for _, r := range b.renderers {
log.Debug("Adding plugin to multi-renderer", slog.String("plugin", r.Name()))
multi.Use(r)
}
log.Debug("Overriding renderers slice")
b.renderers = make([]RendererPlugin, 1)
b.renderers[0] = multi
return b.render(src, w)
}

View File

@@ -16,7 +16,6 @@
package blogo
import (
"errors"
"io"
"io/fs"
)
@@ -25,8 +24,6 @@ type Plugin interface {
Name() string
}
var ErrRendererNotSupportedFile = errors.New("this file is not supported by renderer")
type RendererPlugin interface {
Plugin
Render(src fs.File, out io.Writer) error

153
blogo/renderer.go Normal file
View File

@@ -0,0 +1,153 @@
package blogo
import (
"bytes"
"errors"
"fmt"
"io"
"io/fs"
"log/slog"
)
var ErrRendererNotSupportedFile = errors.New("this file is not supported by renderer")
const multiRendererPluginName = "blogo-multirenderer"
type MultiRenderer interface {
RendererPlugin
Use(Plugin)
}
type multiRenderer struct {
renderers []RendererPlugin
skipOnError bool
panicOnInit bool
log *slog.Logger
}
type MultiRendererOpts struct {
SkipOnError *bool
PanicOnInit *bool
Logger *slog.Logger
}
func NewMultiRenderer(opts ...MultiRendererOpts) MultiRenderer {
opt := MultiRendererOpts{}
if len(opts) > 0 {
opt = opts[0]
}
if opt.SkipOnError == nil {
d := true
opt.SkipOnError = &d
}
if opt.PanicOnInit == nil {
d := true
opt.PanicOnInit = &d
}
if opt.Logger == nil {
opt.Logger = slog.New(slog.NewTextHandler(io.Discard, &slog.HandlerOptions{}))
}
opt.Logger = opt.Logger.WithGroup(multiRendererPluginName)
return &multiRenderer{
renderers: []RendererPlugin{},
skipOnError: *opt.SkipOnError,
panicOnInit: *opt.PanicOnInit,
log: opt.Logger,
}
}
func (p *multiRenderer) Name() string {
return multiRendererPluginName
}
func (p *multiRenderer) Use(plugin Plugin) {
log := p.log.With(slog.String("plugin", plugin.Name()))
if plg, ok := plugin.(RendererPlugin); ok {
log.Debug("Added renderer plugin")
p.renderers = append(p.renderers, plg)
} else {
m := fmt.Sprintf("failed to add plugin %q, since it doesn't implement RendererPlugin", plugin.Name())
log.Error(m)
if p.panicOnInit {
panic(fmt.Sprintf("%s: %s", multiRendererPluginName, m))
}
}
}
func (p *multiRenderer) Render(f fs.File, w io.Writer) error {
mf := newMultiRendererFile(f)
for _, r := range p.renderers {
log := p.log.With(slog.String("plugin", r.Name()))
log.Debug("Trying to render with plugin")
err := r.Render(f, w)
if err == nil {
break
}
if !p.skipOnError && !errors.Is(err, ErrRendererNotSupportedFile) {
log.Error("Failed to render using plugin", slog.String("error", err.Error()))
return errors.Join(fmt.Errorf("failed to render using plugin %q", p.Name()), err)
}
log.Debug("Unable to render using plugin", slog.String("error", err.Error()))
log.Debug("Resetting file for next read")
if err := mf.Reset(); err != nil {
log.Error("Failed to reset file read offset", slog.String("error", err.Error()))
return errors.Join(fmt.Errorf("failed to reset file read offset"), err)
}
}
return nil
}
type multiRendererFile struct {
fs.File
buf *bytes.Buffer
reader io.Reader
}
func newMultiRendererFile(f fs.File) *multiRendererFile {
if _, ok := f.(io.Seeker); ok {
return &multiRendererFile{
File: f,
reader: f,
}
}
var buf bytes.Buffer
return &multiRendererFile{
File: f,
reader: io.TeeReader(f, &buf),
buf: &buf,
}
}
func (f *multiRendererFile) Read(p []byte) (int, error) {
return f.reader.Read(p)
}
func (f *multiRendererFile) Reset() error {
if s, ok := f.File.(io.Seeker); ok {
_, err := s.Seek(0, io.SeekStart)
return err
}
var buf bytes.Buffer
r := io.MultiReader(f.buf, f.File)
f.reader = io.TeeReader(r, &buf)
f.buf = &buf
return nil
}