exar-net 0.1.0

Exar DB's TCP protocol
Documentation 
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use exar::*;

use std::fmt::{Display, Formatter, Result as DisplayResult};

/// A list specifying categories of TCP message.
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum TcpMessage {
    /// Message used to initialize a connection to Exar DB.
    Connect(String, Option<String>, Option<String>),
    /// Message used to acknowledge a successful connection.
    Connected,
    /// Message used to publish an event into a collection.
    Publish(Event),
    /// Message used to acknowledge a successfully published event.
    Published(u64),
    /// Message used to subscribe to an event stream.
    Subscribe(bool, u64, Option<u64>, Option<String>),
    /// Message used to acknowledge a successful subscription.
    Subscribed,
    /// Message containing an event.
    Event(Event),
    /// Message signaling the end of an event stream.
    EndOfEventStream,
    /// Message containing an error.
    Error(DatabaseError)
}

impl ToTabSeparatedString for TcpMessage {
    fn to_tab_separated_string(&self) -> String {
        match *self {
            TcpMessage::Connect(ref collection_name, ref username, ref password) => {
                match (username, password) {
                    (&Some(ref username), &Some(ref password)) => {
                        tab_separated!("Connect", collection_name, username, password)
                    },
                    _ => tab_separated!("Connect", collection_name)
                }
            },
            TcpMessage::Connected => tab_separated!("Connected"),
            TcpMessage::Publish(Event { ref data, ref tags, ref timestamp, .. }) => {
                tab_separated!("Publish", tags.join(" "), timestamp, data)
            },
            TcpMessage::Published(ref event_id) => tab_separated!("Published", event_id),
            TcpMessage::Subscribe(ref live, ref offset, ref limit, ref tag) => {
                match (limit, tag) {
                    (&Some(ref limit), &Some(ref tag)) => tab_separated!("Subscribe", live, offset, limit, tag),
                    (&Some(ref limit), &None) => tab_separated!("Subscribe", live, offset, limit),
                    (&None, &Some(ref tag)) => tab_separated!("Subscribe", live, offset, 0, tag),
                    _ => tab_separated!("Subscribe", live, offset)
                }
            },
            TcpMessage::Subscribed => tab_separated!("Subscribed"),
            TcpMessage::Event(ref event) => tab_separated!("Event", event.to_tab_separated_string()),
            TcpMessage::EndOfEventStream => tab_separated!("EndOfEventStream"),
            TcpMessage::Error(ref error) => tab_separated!("Error", error.to_tab_separated_string())
        }
    }
}

impl FromTabSeparatedStr for TcpMessage {
    fn from_tab_separated_str(s: &str) -> Result<Self, ParseError> {
        let mut parser = TabSeparatedParser::new(2, s);
        let message_type: String = try!(parser.parse_next());
        match &message_type[..] {
            "Connect" => {
                let message_data: String = try!(parser.parse_next());
                let mut parser = TabSeparatedParser::new(3, &message_data);
                let collection_name = try!(parser.parse_next());
                let username = parser.parse_next().ok();
                let password = parser.parse_next().ok();
                Ok(TcpMessage::Connect(collection_name, username, password))
            },
            "Connected" => Ok(TcpMessage::Connected),
            "Publish" => {
                let message_data: String = try!(parser.parse_next());
                let mut parser = TabSeparatedParser::new(3, &message_data);
                let tags: String = try!(parser.parse_next());
                let timestamp = try!(parser.parse_next());
                let data: String = try!(parser.parse_next());
                let tags: Vec<_> = tags.split(" ").collect();
                Ok(TcpMessage::Publish(Event::new(&data, tags).with_timestamp(timestamp)))
            },
            "Published" => {
                let event_id = try!(parser.parse_next());
                Ok(TcpMessage::Published(event_id))
            },
            "Subscribe" => {
                let message_data: String = try!(parser.parse_next());
                let mut parser = TabSeparatedParser::new(4, &message_data);
                let live = try!(parser.parse_next());
                let offset = try!(parser.parse_next());
                let mut limit = parser.parse_next().ok();
                if limit.unwrap_or(0) <= 0 { limit = None }
                let tag = parser.parse_next().ok();
                Ok(TcpMessage::Subscribe(live, offset, limit, tag))
            },
            "Subscribed" => Ok(TcpMessage::Subscribed),
            "Event" => {
                let message_data: String = try!(parser.parse_next());
                Event::from_tab_separated_str(&message_data).and_then(|event| Ok(TcpMessage::Event(event)))
            },
            "EndOfEventStream" => Ok(TcpMessage::EndOfEventStream),
            "Error" => {
                let message_data: String = try!(parser.parse_next());
                DatabaseError::from_tab_separated_str(&message_data).and_then(|error| Ok(TcpMessage::Error(error)))
            },
            x => Err(ParseError::ParseError(format!("unknown TCP message: {}", x)))
        }
    }
}

impl Display for TcpMessage {
    fn fmt(&self, f: &mut Formatter) -> DisplayResult {
        match *self {
            TcpMessage::Connect(ref collection_name, ref username, ref password) => {
                match (username, password) {
                    (&Some(ref username), &Some(ref password)) => {
                        write!(f, "Connect({}, {}, {})", collection_name, username, password)
                    },
                    _ => write!(f, "Connect({})", collection_name)
                }
            },
            TcpMessage::Connected => write!(f, "Connected"),
            TcpMessage::Publish(ref event) => write!(f, "Publish({})", event),
            TcpMessage::Published(ref event_id) => write!(f, "Published({})", event_id),
            TcpMessage::Subscribe(ref live, ref offset, ref limit, ref tag) => {
                match (limit, tag) {
                    (&Some(ref limit), &Some(ref tag)) => write!(f, "Subscribe({}, {}, {}, {})", live, offset, limit, tag),
                    (&Some(ref limit), &None) => write!(f, "Subscribe({}, {}, {})", live, offset, limit),
                    (&None, &Some(ref tag)) => write!(f, "Subscribe({}, {}, {}, {})", live, offset, 0, tag),
                    _ => write!(f, "Subscribe({}, {})", live, offset)
                }
            },
            TcpMessage::Subscribed => write!(f, "Subscribed"),
            TcpMessage::Event(ref event) => write!(f, "Event({})", event),
            TcpMessage::EndOfEventStream => write!(f, "EndOfEventStream"),
            TcpMessage::Error(ref error) => write!(f, "Error({})", error)
        }
    }
}

#[cfg(test)]
mod tests {
    use exar::*;
    use super::super::*;

    #[test]
    fn test_connect() {
        let message = TcpMessage::Connect("collection".to_owned(), None, None);
        let string = "Connect\tcollection";
        assert_encoded_eq!(message, string);
        assert_decoded_eq!(string, message.clone());
        assert_eq!(format!("{}", message), "Connect(collection)");

        let message = TcpMessage::Connect("collection".to_owned(), Some("username".to_owned()), Some("password".to_owned()));
        let string = "Connect\tcollection\tusername\tpassword";
        assert_encoded_eq!(message, string);
        assert_decoded_eq!(string, message.clone());
        assert_eq!(format!("{}", message), "Connect(collection, username, password)");
    }

    #[test]
    fn test_connected() {
        let message = TcpMessage::Connected;
        let string = "Connected";
        assert_encoded_eq!(message, string);
        assert_decoded_eq!(string, message.clone());
        assert_eq!(format!("{}", message), "Connected");
    }

    #[test]
    fn test_publish() {
        let event = Event::new("data", vec!["tag1", "tag2"]).with_timestamp(1234567890);
        let message = TcpMessage::Publish(event.clone());
        let string = "Publish\ttag1 tag2\t1234567890\tdata";
        assert_encoded_eq!(message, string);
        assert_decoded_eq!(string, message.clone());
        assert_eq!(format!("{}", message), format!("Publish({})", event));
    }

    #[test]
    fn test_published() {
        let message = TcpMessage::Published(1);
        let string = "Published\t1";
        assert_encoded_eq!(message, string);
        assert_decoded_eq!(string, message.clone());
        assert_eq!(format!("{}", message), "Published(1)");
    }

    #[test]
    fn test_subscribe() {
        let message = TcpMessage::Subscribe(true, 0, Some(100), Some("tag1".to_owned()));
        let string = "Subscribe\ttrue\t0\t100\ttag1";
        assert_encoded_eq!(message, string);
        assert_decoded_eq!(string, message.clone());
        assert_eq!(format!("{}", message), "Subscribe(true, 0, 100, tag1)");

        let message = TcpMessage::Subscribe(true, 0, Some(100), None);
        let string = "Subscribe\ttrue\t0\t100";
        assert_encoded_eq!(message, string);
        assert_decoded_eq!(string, message.clone());
        assert_eq!(format!("{}", message), "Subscribe(true, 0, 100)");

        let message = TcpMessage::Subscribe(true, 0, None, Some("tag1".to_owned()));
        let string = "Subscribe\ttrue\t0\t0\ttag1";
        assert_encoded_eq!(message, string);
        assert_decoded_eq!(string, message.clone());
        assert_eq!(format!("{}", message), "Subscribe(true, 0, 0, tag1)");

        let message = TcpMessage::Subscribe(true, 0, None, None);
        let string = "Subscribe\ttrue\t0";
        assert_encoded_eq!(message, string);
        assert_decoded_eq!(string, message.clone());
        assert_eq!(format!("{}", message), "Subscribe(true, 0)");
    }

    #[test]
    fn test_subscribed() {
        let message = TcpMessage::Subscribed;
        let string = "Subscribed";
        assert_encoded_eq!(message, string);
        assert_decoded_eq!(string, message.clone());
        assert_eq!(format!("{}", message), "Subscribed");
    }

    #[test]
    fn test_event() {
        let event = Event::new("data", vec!["tag1", "tag2"]).with_id(1).with_timestamp(1234567890);
        let message = TcpMessage::Event(event.clone());
        let string = "Event\t1\t1234567890\ttag1 tag2\tdata";
        assert_encoded_eq!(message, string);
        assert_decoded_eq!(string, message.clone());
        assert_eq!(format!("{}", message), format!("Event({})", event));
    }

    #[test]
    fn test_end_of_event_stream() {
        let message = TcpMessage::EndOfEventStream;
        let string = "EndOfEventStream";
        assert_encoded_eq!(message, string);
        assert_decoded_eq!(string, message.clone());
        assert_eq!(format!("{}", message), "EndOfEventStream");
    }

    #[test]
    fn test_error() {
        let message = TcpMessage::Error(DatabaseError::AuthenticationError);
        let string = "Error\tAuthenticationError";
        assert_encoded_eq!(message, string);
        assert_decoded_eq!(string, message.clone());
        assert_eq!(format!("{}", message), "Error(authentication failure)");
    }
}