new separate receiver

slsReceiverSoftware/slsReceiver/eigerReceiver/RestHelper.h

@@ -0,0 +1,195 @@
+/**
+ * @file   RestHelper.h
+ * @author Leonardo Sala <leonardo.sala@psi.ch>
+ * @date   Tue Mar 25 09:28:19 2014
+ * 
+ * @brief  
+ * 
+ * 
+ */
+
+#include <Poco/Net/HTTPClientSession.h>
+#include <Poco/Net/HTTPRequest.h>
+#include <Poco/Net/HTTPResponse.h>
+#include <Poco/StreamCopier.h>
+#include <Poco/Path.h>
+#include <Poco/URI.h>
+#include <Poco/Exception.h>
+#include <Poco/Timespan.h>
+
+#include "JsonBox/Value.h"
+
+#include <iostream>
+#include <string>
+#include <exception>
+
+/// HTTP timeout in seconds, default is 8
+#define HTTP_TIMEOUT 10
+/// Number of connection tries
+#define N_CONNECTION_TRIES 3
+
+using namespace Poco::Net;
+using namespace Poco;
+using namespace std;
+
+class RestHelper {
+ public:
+
+  ~RestHelper(){};
+
+  void init(string hostname, int port){
+    /** Initialize the RestHelper. Hostname and port parameters are not supposed to change.
+     *  
+     * 
+     * @param hostname FQDN of the host to connect to , e.g. www.iamfake.org, or sodoi.org
+     * @param port 
+     * 
+     * @return 
+     */
+
+    full_hostname = "http://"+hostname;
+    session = new HTTPClientSession(hostname,port );
+    session->setKeepAliveTimeout( Timespan( HTTP_TIMEOUT,0) );
+  };
+
+
+  int get_json(string request, string* answer){
+    /** Retrieves a reply from the RESTful webservice. 
+     * 
+     * 
+     * @param request Request without the hostname, e.g. if the full request would have been http://fake.org/fakemethod, request=fakemethod
+     * @param answer 
+     * 
+     * @return 0 if successful, -1 if failure happens.
+     */    
+    URI * uri = new URI(full_hostname+"/"+request);
+    string path(uri->getPathAndQuery());
+    if (path.empty()) path = "/";
+
+    // send request
+    HTTPRequest req(HTTPRequest::HTTP_GET, path, HTTPMessage::HTTP_1_1);
+    req.setContentType("application/json\r\n");
+    int code = send_request(session, req, answer);
+    delete uri;
+    return code;
+  };
+
+
+  int get_json(string request,  JsonBox::Value* json_value){
+    /** 
+     * 
+     * 
+     * @param request 
+     * @param json_value 
+     * 
+     * @return 
+     */    
+    URI *uri = new URI(full_hostname+"/"+request);
+    string path(uri->getPathAndQuery());
+    if (path.empty()) path = "/";
+    // send request
+    HTTPRequest req(HTTPRequest::HTTP_GET, path, HTTPMessage::HTTP_1_1);
+    req.setContentType("application/json\r\n");
+    string answer;
+    int code = send_request(session, req, &answer);
+    json_value->loadFromString(answer);
+    delete uri;
+    return code;
+  };
+
+
+  int post_json(string request, string *answer, string request_body=""){
+    /** 
+     * 
+     * 
+     * @param request 
+     * @param answer 
+     * @param request_body Eventual arguments to the URL, e.g. action=login&name=mammamia
+     * 
+     * @return 
+     */
+    //from: http://stackoverflow.com/questions/1499086/poco-c-net-ssl-how-to-post-https-request
+    URI *uri = new URI(full_hostname+"/"+request);
+    string path(uri->getPathAndQuery());
+    if (path.empty()) path = "/";
+    HTTPRequest req(HTTPRequest::HTTP_POST, path, HTTPMessage::HTTP_1_1 );
+    req.setContentType("application/json\r\n");
+    req.setContentLength( request.length() );
+    int code = send_request(session, req, answer, request_body);
+    delete uri;
+    return code;
+  }
+
+
+  int post_json(string request,  JsonBox::Value* json_value, string request_body=""){
+    /** 
+     * 
+     * 
+     * @param request 
+     * @param json_value 
+     * @param request_body Eventual arguments to the URL, e.g. action=login&name=mammamia
+     * 
+     * @return 
+     */
+
+    URI *uri = new URI(full_hostname+"/"+request);
+    string path(uri->getPathAndQuery());
+    if (path.empty()) path = "/";
+    HTTPRequest req(HTTPRequest::HTTP_POST, path, HTTPMessage::HTTP_1_1 );
+    req.setContentType("application/json\r\n");
+    req.setContentLength( request.length() );
+    string answer;
+    int code = send_request(session, req, &answer, request_body);
+    json_value->loadFromString(answer);
+    delete uri;
+    return code;
+  }
+    
+
+ private:
+  //URI * uri;
+  HTTPClientSession *session;
+  string full_hostname;
+
+  int send_request(HTTPClientSession *session, HTTPRequest &req, string *answer, string request_body=""){
+    /** 
+     * 
+     * 
+     * @param session 
+     * @param req 
+     * @param answer 
+     * @param request_body 
+     * 
+     * @return 
+     */
+    
+    int n=0;
+    int code = -1;
+    while(n<N_CONNECTION_TRIES){
+      try {
+	if (request_body == "")
+	  session->sendRequest( (req) );
+	else
+	  session->sendRequest( (req) ) << request_body;
+
+	HTTPResponse res;
+	istream &is = session->receiveResponse(res);
+	StreamCopier::copyToString(is, *answer);
+	code = res.getStatus();
+	if (code != 200){
+	  cout << "HTTP ERROR " << res.getStatus() << ": " << res.getReason() << endl;
+	  code = -1;
+	}
+	return code;
+      }
+      catch (exception& e){
+	cout << "Exception connecting to "<< full_hostname << ": "<< e.what() << ", sleeping " << HTTP_TIMEOUT << " seconds\n";
+	sleep(HTTP_TIMEOUT);
+      }
+      n+=1;
+    }
+
+    return code;
+  }
+
+};