Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Code Block
languagejava
titleProcessing the file
private File processFile(File tempFile, String originalFileId) throws Exception  {
    
    Runtime r = Runtime.getRuntime();
    Process p;     // Process tracks one external native process
      
    String tempDir = System.getProperty("java.io.tmpdir");
    if (new Character(tempDir.charAt(tempDir.length()-1)).toString().equals(System.getProperty("file.separator")) == false){
      tempDir = tempDir + System.getProperty("file.separator");
    }
      
    String processCmd = "";
    String operSystem = System.getProperty("os.name").toLowerCase();

	// TODO: windows impl
    if(operSystem.indexOf("nix") >= 0 || operSystem.indexOf("nux") >= 0 || operSystem.indexOf("aix") > 0 ){
      "wc -w " + tempDir +  tempFile.getName();
    }  
      
    p = r.exec(processCmd, null, new File(tempDir));
    StreamGobbler outputGobbler = new StreamGobbler(p.getInputStream(), "INFO", log);
    StreamGobbler errorGobbler = new StreamGobbler(p.getErrorStream(),"ERROR", log);
    outputGobbler.start();
    errorGobbler.start();
    p.waitFor();
      
    File outFile = new File(tempDir + tempFile.getName().substring(0, tempFile.getName().lastIndexOf(".")) + ".txt");
    tempFile.delete();
    if(!Files.exists(outFile.toPath()))
      throw new Exception("File not processed correctly. File is possibly corrupt.");
      
  return outFile;
      
}

 

 
Anchor
C++
C++
C++

Code Block
languagecpp
titleConnecting to RabbitMQ
#include <amqpcpp.h>

namespace CPPExample {

  class RabbitMQConnectionHandler : public AMQP::ConnectionHandler {
      /**
      *  Method that is called by the AMQP library every time it has data
      *  available that should be sent to RabbitMQ. 
      *  @param  connection  pointer to the main connection object  
      *  @param  data        memory buffer with the data that should be sent to RabbitMQ
      *  @param  size        size of the buffer
      */
     virtual void onData(AMQP::Connection *connection, const char *data, size_t size)
     {
         // @todo 
         //  Add your own implementation, for example by doing a call to the
         //  send() system call. But be aware that the send() call may not
         //  send all data at once, so you also need to take care of buffering
         //  the bytes that could not immediately be sent, and try to send 
         //  them again when the socket becomes writable again
     }

      /**
      *  Method that is called by the AMQP library when the login attempt 
      *  succeeded. After this method has been called, the connection is ready 
      *  to use.
      *  @param  connection      The connection that can now be used
      */
      virtual void onConnected(Connection *connection)
      {
         // @todo
         //  add your own implementation, for example by creating a channel 
         //  instance, and start publishing or consuming
      }

      /**
      *  Method that is called by the AMQP library when a fatal error occurs
      *  on the connection, for example because data received from RabbitMQ
      *  could not be recognized.
      *  @param  connection      The connection on which the error occured
      *  @param  message         A human readable error message
      */
      virtual void onError(Connection *connection, const std::string &message)
      {
        // @todo
        //  add your own implementation, for example by reporting the error
        //  to the user of your program, log the error, and destruct the 
        //  connection object because it is no longer in a usable state
      }
  };

}

...

Code Block
languagepy
titleOn Message
def on_message(channel, method, header, body):
	global logger
	statusreport = {}
	inputfile=None
	try:
		# parse body back from json
		jbody=json.loads(body)

		host=jbody['host']
		fileid=jbody['id']
		intermediatefileid=jbody['intermediateId']
		if not (host.endswith('/')):
			host += '/'
		
		# for status reports
		statusreport['file_id'] = fileid
		statusreport['extractor_id'] = 'wordCount' 

		# print what we are doing
		logger.debug("[%s] started processing", fileid)

		# fetch data
		statusreport['status'] = 'Downloading file.'
		statusreport['start'] = time.strftime('%Y-%m-%dT%H:%M:%S')
		channel.basic_publish(exchange='',
							routing_key=header.reply_to,
							properties=pika.BasicProperties(correlation_id = \
														header.correlation_id),
							body=json.dumps(statusreport)) 
		url=host + 'api/files/' + intermediatefileid + '?key=' + playserverKey
		r=requests.get(url, stream=True)
		r.raise_for_status()
		(fd, inputfile)=tempfile.mkstemp()
		with os.fdopen(fd, "w") as f:
			for chunk in r.iter_content(chunk_size=10*1024):
				f.write(chunk)


		# create word count
		statusreport['status'] = 'Creating word count.'
		statusreport['start'] = time.strftime('%Y-%m-%dT%H:%M:%S')
		channel.basic_publish(exchange='',
							routing_key=header.reply_to,
							properties=pika.BasicProperties(correlation_id = \
														header.correlation_id),
							body=json.dumps(statusreport))
		create_word_count(inputfile, ext, host, fileid)

		# Ack
		channel.basic_ack(method.delivery_tag)
		logger.debug("[%s] finished processing", fileid)
	except subprocess.CalledProcessError as e:
		logger.exception("[%s] error processing [exit code=%d]\n%s", fileid, e.returncode, e.output)
		statusreport['status'] = 'Error processing.'
		statusreport['start'] = time.strftime('%Y-%m-%dT%H:%M:%S') 
		channel.basic_publish(exchange='',
                routing_key=header.reply_to,
                properties=pika.BasicProperties(correlation_id = \
                                                header.correlation_id),
                body=json.dumps(statusreport)) 
	except:
		logger.exception("[%s] error processing", fileid)
		statusreport['status'] = 'Error processing.'
		statusreport['start'] = time.strftime('%Y-%m-%dT%H:%M:%S') 
		channel.basic_publish(exchange='',
                routing_key=header.reply_to,
                properties=pika.BasicProperties(correlation_id = \
                                                header.correlation_id),
                body=json.dumps(statusreport))		
	finally:
		statusreport['status'] = 'DONE.'
		statusreport['start'] = time.strftime('%Y-%m-%dT%H:%M:%S')
		channel.basic_publish(exchange='',
							routing_key=header.reply_to,
							properties=pika.BasicProperties(correlation_id = \
														header.correlation_id),
							body=json.dumps(statusreport))
		if inputfile is not None:
			try:
				os.remove(inputfile)
			except OSError:
				pass
			except UnboundLocalError:
				pass

 

Calling R Scripts from Python

 

Code Block
languagepy
titleCreate Word Count
def create_word_count(inputfile, ext, host, fileid):
	global logger

	(fd, inputfile)=tempfile.mkstemp(suffix='.' + ext)
	try:
		# make syscall to wc
		subprocess.check_output(['wc', inputfile], stderr=subprocess.STDOUT)

		if(os.path.getsize(wcfile) == 0):
			raise Exception("File is empty.")

		# upload word count file

Calling R Scripts from Python


Anchor
Versus
Versus
Versus Extractors

...