loader.go

package web

import (
	"bytes"
	"io"
	"net/http"
	"net/url"
	
	"github.com/gravestench/director/pkg/common/cache"
)

type Loader struct {
	cache *cache.Cache
}

const (
	imageBudget = 100
)

func New() *Loader {
	return &Loader{
		cache: cache.New(imageBudget),
	}
}

func (l *Loader) Name() string {
	return "HTTP Web Loader"
}

func (l *Loader) Exists(p string) bool {
	if _, err := url.Parse(p); err != nil {
		return false
	}

	resp, err := http.Get(p)
	if err != nil {
		return false
	}

	if resp.StatusCode != 200 {
		return false
	}

	return true
}

func (l *Loader) Load(p string) (io.ReadSeeker, error) {
	if entry, found := l.cache.Retrieve(p); found {
		rs, ok := entry.(io.ReadSeeker)
		if !ok {
			return nil, nil
		}

		return rs, nil
	}

	resp, err := http.Get(p)
	if err != nil {
		return nil, err
	}

	data, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}

	go func() {
		_ = l.cache.Insert(p, bytes.NewReader(data), 1)
	}()

	return nil, nil
}