amqp 0.0.8

AMQP/RabbitMQ protocol client.
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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205

use channel::Channel;
use channel::ConsumerCallback;
use table::Table;
use framing::{ContentHeaderFrame, FrameType, Frame};
use protocol::{MethodFrame, basic, Method};
use protocol::basic::{BasicProperties, GetOk, Consume, ConsumeOk, Deliver, Publish, Ack, Nack, Reject, Qos, QosOk};
use std::sync::mpsc::{sync_channel, Receiver, SyncSender};

enum AckAction {
    Ack(u64),
    Nack(u64, bool),
    Reject(u64, bool)
}

pub struct GetIterator <'a> {
    queue: &'a str,
    no_ack: bool,
    channel: &'a mut Channel,
    ack_receiver: Receiver<AckAction>,
    ack_sender: SyncSender<AckAction>
}

pub trait Basic <'a> {
    fn basic_get(&'a mut self, queue: &'a str, no_ack: bool) -> GetIterator<'a>;
    fn basic_consume(&mut self, callback: ConsumerCallback,
    queue: &str, consumer_tag: &str, no_local: bool, no_ack: bool,
    exclusive: bool, nowait: bool, arguments: Table) -> String;
    fn start_consuming(&mut self);
    fn basic_publish(&mut self, exchange: &str, routing_key: &str, mandatory: bool, immediate: bool,
                         properties: BasicProperties, content: Vec<u8>);
    fn basic_ack(&mut self, delivery_tag: u64, multiple: bool);
    fn basic_nack(&mut self, delivery_tag: u64, multiple: bool, requeue: bool);
    fn basic_reject(&mut self, delivery_tag: u64, requeue: bool);
    fn basic_prefetch(&mut self, prefetch_count: u16);
    fn basic_qos(&mut self, prefetch_size: u32, prefetch_count: u16, global: bool);
}

// #[derive(Debug)]
pub struct GetResult {
    pub reply: GetOk,
    pub headers: BasicProperties,
    pub body: Vec<u8>,
    ack_sender: SyncSender<AckAction>
}

impl <'a> Iterator for GetIterator<'a > {
    type Item = GetResult;

    fn next(&mut self) -> Option<Self::Item> {
        self.ack_message();
        let get = &basic::Get{ ticket: 0, queue: self.queue.to_string(), no_ack: self.no_ack };
        let method_frame = self.channel.raw_rpc(get);
        match method_frame.method_name() {
            "basic.get-ok" => {
                let reply: basic::GetOk = Method::decode(method_frame).ok().unwrap();
                let headers = self.channel.read_headers().ok().unwrap();
                let body = self.channel.read_body(headers.body_size).ok().unwrap();
                let properties = BasicProperties::decode(headers).ok().unwrap();
                Some(GetResult {headers: properties, reply: reply, body: body, ack_sender: self.ack_sender.clone()})
            }
            "basic.get-empty" => None,
            method => panic!(format!("Not expected method: {}", method))
        }
    }
}

/// Will acknowledge

impl <'a> Drop for GetIterator <'a> {
    fn drop(&mut self) {
        self.ack_message();
    }
}

impl <'a> GetIterator <'a> {
    fn ack_message(&mut self) {
        self.ack_receiver.try_recv().map(|ack_action|
            match ack_action {
                AckAction::Ack(delivery_tag) => self.channel.basic_ack(delivery_tag, false),
                AckAction::Nack(delivery_tag, requeue) => self.channel.basic_nack(delivery_tag, false, requeue),
                AckAction::Reject(delivery_tag, requeue) => self.channel.basic_reject(delivery_tag, requeue)
            }
        ).unwrap_or(());
    }
}

impl GetResult {
    pub fn ack(&self) {
        self.ack_sender.try_send(AckAction::Ack(self.reply.delivery_tag)).unwrap_or(());
    }
    pub fn nack(&self, requeue: bool) {
        self.ack_sender.try_send(AckAction::Nack(self.reply.delivery_tag, requeue)).unwrap_or(());
    }
    pub fn reject(&self, requeue: bool) {
        self.ack_sender.try_send(AckAction::Reject(self.reply.delivery_tag, requeue)).unwrap_or(());
    }
}

impl <'a> Basic<'a> for Channel {

    /// Returns a basic iterator.
    /// # Example
    /// ```no_run
    /// use std::default::Default;
    /// use amqp::session::{Options, Session};
    /// use amqp::basic::Basic;
    /// let mut session = match Session::new(Options { .. Default::default() }){
    ///     Ok(session) => session,
    ///     Err(error) => panic!("Failed openning an amqp session: {:?}", error)
    /// };
    /// let mut channel = session.open_channel(1).ok().expect("Can not open a channel");
    /// for get_result in channel.basic_get("my queue", false) {
    ///     println!("Headers: {:?}", get_result.headers);
    ///     println!("Reply: {:?}", get_result.reply);
    ///     println!("Body: {:?}", String::from_utf8_lossy(&get_result.body));
    ///     get_result.ack();
    /// }
    /// ```
    ///
    fn basic_get(&'a mut self, queue: &'a str, no_ack: bool) -> GetIterator<'a> {
        let (tx, rx) = sync_channel::<AckAction>(1);
        GetIterator { channel: self, queue: queue, no_ack: no_ack, ack_receiver: rx, ack_sender: tx }
    }

    fn basic_consume(&mut self, callback: ConsumerCallback,
        queue: &str, consumer_tag: &str, no_local: bool, no_ack: bool,
        exclusive: bool, nowait: bool, arguments: Table) -> String {
        let consume = &Consume {
            ticket: 0, queue: queue.to_string(), consumer_tag: consumer_tag.to_string(),
            no_local: no_local, no_ack: no_ack, exclusive: exclusive, nowait: nowait, arguments: arguments
        };
        let reply: ConsumeOk = self.rpc(consume, "basic.consume-ok").ok().unwrap();
        self.consumers.insert(reply.consumer_tag.clone(), callback);
        reply.consumer_tag
    }

    // Will run the infinite loop, which will receive frames on the given channel & call consumers.
    fn start_consuming(&mut self) {
        loop {
          let frame = self.read();
                match frame.frame_type {
                    FrameType::METHOD => {
                        let method_frame = MethodFrame::decode(frame);
                        match method_frame.method_name() {
                            "basic.deliver" => {
                                let deliver_method : Deliver = Method::decode(method_frame).ok().unwrap();
                                let headers = self.read_headers().ok().unwrap();
                                let body = self.read_body(headers.body_size).ok().unwrap();
                                let properties = BasicProperties::decode(headers).ok().unwrap();
                                let consumer = self.consumers.get(&deliver_method.consumer_tag).map(|&x| x);
                                match consumer {
                                    Some(callback) => (callback)(self, deliver_method, properties, body),
                                    None => {error!("Received deliver frame for the unknown consumer: {}", deliver_method.consumer_tag)}
                                };
                            }
                            _ => {} //TODO: Handle other callbacks as well.
                        }
                    }
                    _ => {}
                }
        }
    }


    fn basic_publish(&mut self, exchange: &str, routing_key: &str, mandatory: bool, immediate: bool,
                         properties: BasicProperties, content: Vec<u8>) {
        let publish = &Publish {
            ticket: 0, exchange: exchange.to_string(),
            routing_key: routing_key.to_string(), mandatory: mandatory, immediate: immediate};
        let properties_flags = properties.flags();
        let content_header = ContentHeaderFrame { content_class: 60, weight: 0, body_size: content.len() as u64,
            properties_flags: properties_flags, properties: properties.encode() };
        let content_header_frame = Frame {frame_type: FrameType::HEADERS, channel: self.id,
            payload: content_header.encode() };
        let content_frame = Frame { frame_type: FrameType::BODY, channel: self.id, payload: content};

        self.send_method_frame(publish);
        self.write(content_header_frame);
        self.write(content_frame);
    }

    fn basic_ack(&mut self, delivery_tag: u64, multiple: bool) {
        self.send_method_frame(&Ack{delivery_tag: delivery_tag, multiple: multiple});
    }

    // Rabbitmq specific
    fn basic_nack(&mut self, delivery_tag: u64, multiple: bool, requeue: bool) {
        self.send_method_frame(&Nack{delivery_tag: delivery_tag, multiple: multiple, requeue: requeue});
    }

    fn basic_reject(&mut self, delivery_tag: u64, requeue: bool) {
        self.send_method_frame(&Reject{delivery_tag: delivery_tag, requeue: requeue});
    }

    fn basic_prefetch(&mut self, prefetch_count:u16 ){
        self.basic_qos(0, prefetch_count, false);
    }

    fn basic_qos(&mut self, prefetch_size: u32, prefetch_count: u16, global: bool){
        let qos=&Qos{prefetch_size: prefetch_size,
                     prefetch_count: prefetch_count,
                     global: global};
        let _reply: QosOk = self.rpc(qos, "basic.qos-ok").ok().unwrap();
    }
}