1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155

extern crate rmp_serde as rmps;
use rmps::{Deserializer, Serializer};
use serde::{Deserialize, Serialize};
use std::io::Cursor;

extern crate log;
#[cfg(feature = "guest")]
extern crate wapc_guest as guest;
#[cfg(feature = "guest")]
use guest::prelude::*;

#[cfg(feature = "guest")]
pub struct Host {
    binding: String,
}
#[cfg(feature = "guest")]
impl Default for Host {
    fn default() -> Self {
        Host {
            binding: "default".to_string(),
        }
    }
}

#[cfg(feature = "guest")]
/// Creates a named host binding for the event streams capability
pub fn host(binding: &str) -> Host {
    Host {
        binding: binding.to_string(),
    }
}

#[cfg(feature = "guest")]
/// Creates the default host binding for the event streams capability
pub fn default() -> Host {
    Host::default()
}

#[cfg(feature = "guest")]
impl Host {
    /// Writes a map of key-value pairs to the given event stream
    pub fn write_event(
        &self,
        stream_id: String,
        values: std::collections::HashMap<String, String>,
    ) -> HandlerResult<EventAck> {
        let input_args = WriteEventArgs {
            stream_id: stream_id,
            values: values,
        };
        host_call(
            &self.binding,
            "wasmcloud:eventstreams",
            "WriteEvent",
            &serialize(input_args)?,
        )
        .map(|vec| {
            let resp = deserialize::<EventAck>(vec.as_ref()).unwrap();
            resp
        })
        .map_err(|e| e.into())
    }

    /// Queries the stream per the parameters in the supplied query
    pub fn query_stream(&self, query: StreamQuery) -> HandlerResult<EventList> {
        host_call(
            &self.binding,
            "wasmcloud:eventstreams",
            "QueryStream",
            &serialize(query)?,
        )
        .map(|vec| {
            let resp = deserialize::<EventList>(vec.as_ref()).unwrap();
            resp
        })
        .map_err(|e| e.into())
    }
}

#[derive(Debug, PartialEq, Deserialize, Serialize, Default, Clone)]
pub struct WriteEventArgs {
    #[serde(rename = "streamId")]
    pub stream_id: String,
    #[serde(rename = "values")]
    pub values: std::collections::HashMap<String, String>,
}

#[derive(Debug, PartialEq, Deserialize, Serialize, Default, Clone)]
pub struct Event {
    #[serde(rename = "eventId")]
    pub event_id: String,
    #[serde(rename = "streamId")]
    pub stream_id: String,
    #[serde(rename = "values")]
    pub values: std::collections::HashMap<String, String>,
}

#[derive(Debug, PartialEq, Deserialize, Serialize, Default, Clone)]
pub struct EventAck {
    #[serde(rename = "eventId")]
    pub event_id: Option<String>,
    #[serde(rename = "error")]
    pub error: Option<String>,
}

#[derive(Debug, PartialEq, Deserialize, Serialize, Default, Clone)]
pub struct EventList {
    #[serde(rename = "events")]
    pub events: Vec<Event>,
}

#[derive(Debug, PartialEq, Deserialize, Serialize, Default, Clone)]
pub struct StreamQuery {
    #[serde(rename = "streamId")]
    pub stream_id: String,
    #[serde(rename = "range")]
    pub range: Option<TimeRange>,
    #[serde(rename = "count")]
    pub count: u64,
}

#[derive(Debug, PartialEq, Deserialize, Serialize, Default, Clone)]
pub struct TimeRange {
    #[serde(rename = "minTime")]
    pub min_time: u64,
    #[serde(rename = "maxTime")]
    pub max_time: u64,
}

/// The standard function for serializing codec structs into a format that can be
/// used for message exchange between actor and host. Use of any other function to
/// serialize could result in breaking incompatibilities.
pub fn serialize<T>(
    item: T,
) -> ::std::result::Result<Vec<u8>, Box<dyn std::error::Error + Send + Sync>>
where
    T: Serialize,
{
    let mut buf = Vec::new();
    item.serialize(&mut Serializer::new(&mut buf).with_struct_map())?;
    Ok(buf)
}

/// The standard function for de-serializing codec structs from a format suitable
/// for message exchange between actor and host. Use of any other function to
/// deserialize could result in breaking incompatibilities.
pub fn deserialize<'de, T: Deserialize<'de>>(
    buf: &[u8],
) -> ::std::result::Result<T, Box<dyn std::error::Error + Send + Sync>> {
    let mut de = Deserializer::new(Cursor::new(buf));
    match Deserialize::deserialize(&mut de) {
        Ok(t) => Ok(t),
        Err(e) => Err(format!("Failed to de-serialize: {}", e).into()),
    }
}