wamp_core/messages/

subscribe.rs

use super::{MessageDirection, WampMessage};
use crate::{messages::helpers, roles::Roles};
use serde::{de::Visitor, Deserialize, Serialize};
use serde_json::Value;
use std::marker::PhantomData;

#[derive(Debug, Clone, PartialEq, Eq)]
/// # Subscribe - [wamp-proto](https://wamp-proto.org/wamp_latest_ietf.html#name-subscribe-2)
/// Represents an unsubscribe frame in the WAMP protocol.
/// ## Examples
/// ```
/// use wamp_core::messages::Subscribe;
/// use wamp_core::subscribe;
/// use serde_json::json;
///
/// # let mut subscribed1 = subscribe!("topic");
///
/// let subscribed = Subscribe {
///     request_id: 1,
///     topic: "topic".to_string(),
///     options: json!({})
/// };
/// # subscribed1.options = json!({});
/// # assert_eq!(subscribed, subscribed1);
/// ```
/// ### Serializer
/// Implements serde Serialize trait for Subscribe
/// ```
/// use wamp_core::messages::Subscribe;
/// use serde_json::{json, to_string};
/// use wamp_core::subscribe;
///
/// let data = r#"[32,1,{},"com.myapp.mytopic1"]"#;
///
/// let subscribe1 = subscribe!("com.myapp.mytopic1");
///
/// let subscribe = Subscribe {
///     request_id: 1,
///     topic: "com.myapp.mytopic1".to_string(),
///     options: json!({})
/// };
///
/// let data2 = to_string(&subscribe1).unwrap();
/// let data3 = to_string(&subscribe).unwrap();
///
/// assert_eq!(data, data2);
/// assert_eq!(data2, data3);
/// ```
/// ### Deserializer
/// Implements serde Deserialize trait for Subscribe
/// ```
/// use wamp_core::messages::Subscribe;
/// use serde_json::from_str;
/// use wamp_core::subscribe;
///
/// let data = r#"[32,1,{},"com.myapp.mytopic1"]"#;
///
/// let subscribe = from_str::<Subscribe>(data).unwrap();
///
/// let subscribe2 = subscribe!("com.myapp.mytopic1");
///
/// assert_eq!(subscribe, subscribe2);
/// ```
pub struct Subscribe {
    pub request_id: u64,
    pub options: Value,
    pub topic: String,
}

#[macro_export]
/// # Subscribe Macro - [wamp-proto](https://wamp-proto.org/wamp_latest_ietf.html#name-subscribe-2)
/// Macro that allows for default implementations of subscribe with empty or custom options and auto incremented request id.
/// ## Examples
/// ```
/// use wamp_core::messages::{self, Subscribe};
/// use wamp_core::subscribe;
/// use serde_json::json;
///
/// let topic = "topic";
///
/// // Construct with default empty options object
/// let subscribe = subscribe!(topic);
///
/// let subscribe2 = Subscribe {
///     request_id: 1,
///     options: json!({}),
///     topic: topic.to_string()
/// };
///
/// assert_eq!(subscribe, subscribe2);
/// ```
macro_rules! subscribe {
    ($topic:expr) => {
        subscribe! {$topic, serde_json::json!({})}
    };
    ($topic:expr, $options:expr) => {
        Subscribe {
            topic: $topic.to_string(),
            options: $options,
            request_id: $crate::factories::increment(),
        }
    };
}

impl WampMessage for Subscribe {
    const ID: u64 = 32;

    fn direction(role: Roles) -> &'static MessageDirection {
        match role {
            Roles::Callee => &MessageDirection {
                receives: &false,
                sends: &false,
            },
            Roles::Caller => &MessageDirection {
                receives: &false,
                sends: &false,
            },
            Roles::Publisher => &MessageDirection {
                receives: &false,
                sends: &false,
            },
            Roles::Subscriber => &MessageDirection {
                receives: &false,
                sends: &true,
            },
            Roles::Dealer => &MessageDirection {
                receives: &false,
                sends: &false,
            },
            Roles::Broker => &MessageDirection {
                receives: &true,
                sends: &false,
            },
        }
    }
}

impl Serialize for Subscribe {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: serde::Serializer,
    {
        (Self::ID, &self.request_id, &self.options, &self.topic).serialize(serializer)
    }
}

impl<'de> Deserialize<'de> for Subscribe {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        struct SubscribeVisitor(
            PhantomData<u64>,
            PhantomData<u64>,
            PhantomData<Value>,
            PhantomData<String>,
        );

        impl<'vi> Visitor<'vi> for SubscribeVisitor {
            type Value = Subscribe;

            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
                formatter.write_str("A sequence of Subscribe components.")
            }

            fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
            where
                A: serde::de::SeqAccess<'vi>,
            {
                let message_id: u64 = helpers::deser_seq_element(
                    &mut seq,
                    "Message id must be present and type u64.",
                )?;
                helpers::validate_id::<Subscribe, A, _>(&message_id, "Subscribe")?;
                let request_id: u64 = helpers::deser_seq_element(
                    &mut seq,
                    "Request ID must be present and type u64",
                )?;
                let options: Value = helpers::deser_seq_element(
                    &mut seq,
                    "options must be present and object like",
                )?;
                helpers::deser_value_is_object::<A, _>(&options, "options must be object like.")?;
                let topic: String = helpers::deser_seq_element(
                    &mut seq,
                    "topic URI must be present and type String",
                )?;
                helpers::deser_value_is_object::<A, _>(&options, "options must be object like.")?;
                Ok(Subscribe {
                    request_id,
                    options,
                    topic,
                })
            }
        }

        deserializer.deserialize_struct(
            "Subscribe",
            &["request_id", "options", "topic"],
            SubscribeVisitor(PhantomData, PhantomData, PhantomData, PhantomData),
        )
    }
}

#[cfg(test)]
mod tests {
    use serde_json::{from_str, json, to_string};

    use super::Subscribe;

    #[test]
    fn subscribe_test() {
        let d1 = r#"[32,713845233,{},"com.myapp.mytopic1"]"#;
        let r1 = Subscribe {
            request_id: 713845233,
            options: json!({}),
            topic: "com.myapp.mytopic1".to_string(),
        };
        assert_eq!(d1, to_string(&r1).unwrap());
        assert_eq!(r1, from_str::<Subscribe>(d1).unwrap())
    }
}