tutorial-01-wget.cc

/*
  Copyright (c) 2019 Sogou, Inc.

  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.

  Author: Xie Han (xiehan@sogou-inc.com;63350856@qq.com)
*/

#include <netdb.h>
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <string>
#include "workflow/HttpMessage.h"
#include "workflow/HttpUtil.h"
#include "workflow/WFTaskFactory.h"
#include "workflow/WFFacilities.h"

#define REDIRECT_MAX    5
#define RETRY_MAX       2

void wget_callback(WFHttpTask *task)
{
	protocol::HttpRequest *req = task->get_req();
	protocol::HttpResponse *resp = task->get_resp();
	int state = task->get_state();
	int error = task->get_error();

	switch (state)
	{
	case WFT_STATE_SYS_ERROR:
		fprintf(stderr, "system error: %s\n", strerror(error));
		break;
	case WFT_STATE_DNS_ERROR:
		fprintf(stderr, "DNS error: %s\n", gai_strerror(error));
		break;
	case WFT_STATE_SSL_ERROR:
		fprintf(stderr, "SSL error: %d\n", error);
		break;
	case WFT_STATE_TASK_ERROR:
		fprintf(stderr, "Task error: %d\n", error);
		break;
	case WFT_STATE_SUCCESS:
		break;
	}

	if (state != WFT_STATE_SUCCESS)
	{
		fprintf(stderr, "Failed. Press Ctrl-C to exit.\n");
		return;
	}

	std::string name;
	std::string value;

	/* Print request. */
	fprintf(stderr, "%s %s %s\r\n", req->get_method(),
									req->get_http_version(),
									req->get_request_uri());

	protocol::HttpHeaderCursor req_cursor(req);

	while (req_cursor.next(name, value))
		fprintf(stderr, "%s: %s\r\n", name.c_str(), value.c_str());
	fprintf(stderr, "\r\n");

	/* Print response header. */
	fprintf(stderr, "%s %s %s\r\n", resp->get_http_version(),
									resp->get_status_code(),
									resp->get_reason_phrase());

	protocol::HttpHeaderCursor resp_cursor(resp);

	while (resp_cursor.next(name, value))
		fprintf(stderr, "%s: %s\r\n", name.c_str(), value.c_str());
	fprintf(stderr, "\r\n");

	/* Print response body. */
	const void *body;
	size_t body_len;

	resp->get_parsed_body(&body, &body_len);
	fwrite(body, 1, body_len, stdout);
	fflush(stdout);

	fprintf(stderr, "\nSuccess. Press Ctrl-C to exit.\n");
}

static WFFacilities::WaitGroup wait_group(1);

void sig_handler(int signo)
{
	wait_group.done();
}

int main(int argc, char *argv[])
{
	WFHttpTask *task;

	if (argc != 2)
	{
		fprintf(stderr, "USAGE: %s <http URL>\n", argv[0]);
		exit(1);
	}

	signal(SIGINT, sig_handler);

	std::string url = argv[1];
	if (strncasecmp(argv[1], "http://", 7) != 0 &&
		strncasecmp(argv[1], "https://", 8) != 0)
	{
		url = "http://" + url;
	}

	task = WFTaskFactory::create_http_task(url, REDIRECT_MAX, RETRY_MAX,
										   wget_callback);
	protocol::HttpRequest *req = task->get_req();
	req->add_header_pair("Accept", "*/*");
	req->add_header_pair("User-Agent", "Wget/1.14 (linux-gnu)");
	req->add_header_pair("Connection", "close");
	task->start();

	wait_group.wait();
	return 0;
}