utils/contentreader.go

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 utils

import (
	"io/ioutil"
	"net/http"
	"strings"
)

// agnostic util reader to fetch content from web or local path or potentially other places.
type ContentReader struct {
	URLReader
	LocalReader
}

type URLReader struct {
}

func (urlReader *URLReader) ReadUrl(url string) (content []byte, err error) {
	resp, err := http.Get(url)
	Check(err)
	b, err := ioutil.ReadAll(resp.Body)
	defer resp.Body.Close()
	Check(err)
	return b, nil
}

type LocalReader struct {
}

func (localReader *LocalReader) ReadLocal(path string) (content []byte, err error) {
	cont, err := ioutil.ReadFile(path)
	Check(err)
	return cont, nil
}

func Read(url string) (content []byte, err error) {
	if strings.HasPrefix(url, "http") {
		return new(ContentReader).URLReader.ReadUrl(url)
	} else {
		return new(ContentReader).LocalReader.ReadLocal(url)
	}
}