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

// Copyright 2019 Stichting Organism
// Copyright (c) 2018-2019 Prime Type Ltd
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// 	http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use hashbrown::HashMap;
use serde::{Deserialize, Serialize};
use crate::topic::{
    Topic,
    InterestLevel,
    PriorityScore,
    Proximity,
    ProximityScore
};

/// This described a subscription to a topic.
#[derive(Clone, Debug)]
pub struct Subscription {
    pub topic: Topic,
    pub interest_level: InterestLevel,
}

impl Subscription {
    pub fn new(topic: Topic, interest_level: InterestLevel) -> Self {
        Subscription {
            topic,
            interest_level,
        }
    }
}


impl PartialEq<Topic> for Subscription {
    fn eq(&self, topic: &Topic) -> bool {
        &self.topic == topic
    }
}
impl PartialEq<Self> for Subscription {
    fn eq(&self, other: &Self) -> bool {
        self.topic == other.topic
    }
}
impl Eq for Subscription {}
impl PartialOrd<Topic> for Subscription {
    fn partial_cmp(&self, topic: &Topic) -> Option<std::cmp::Ordering> {
        self.topic.partial_cmp(topic)
    }
}
impl PartialOrd<Self> for Subscription {
    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
        self.topic.partial_cmp(&other.topic)
    }
}
impl Ord for Subscription {
    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
        self.topic.cmp(&other.topic)
    }
}
impl std::hash::Hash for Subscription {
    fn hash<H>(&self, state: &mut H)
    where
        H: std::hash::Hasher,
    {
        std::hash::Hash::hash(&self.topic, state)
    }
}

#[derive(Clone, PartialEq, Eq, Debug, Serialize, Deserialize)]
pub struct Subscriptions(HashMap<Topic, InterestLevel>);


impl Default for Subscriptions {
    fn default() -> Self {
        Subscriptions(HashMap::default())
    }
}

impl Subscriptions {
    /// add a new subscription, return the replaced/updated subscription if
    /// topic already present.
    pub fn add(&mut self, subscription: Subscription) -> Option<InterestLevel> {
        self.0
            .insert(subscription.topic, subscription.interest_level)
    }

    pub fn contains(&self, topic: Topic) -> bool {
        self.0.contains_key(&topic)
    }

    pub fn remove(&mut self, subscription: Topic) -> Option<InterestLevel> {
        self.0.remove(&subscription)
    }

    pub fn topics(&self) -> impl Iterator<Item = &Topic> {
        self.0.keys()
    }

    pub fn iter(&self) -> impl Iterator<Item = (&Topic, &InterestLevel)> {
        self.0.iter()
    }

    pub fn iter_mut(&mut self) -> impl Iterator<Item = (&Topic, &mut InterestLevel)> {
        self.0.iter_mut()
    }

    /// retrieve the iterator over the topics common between both subscriptions
    pub fn common_subscriptions<'a>(&'a self, other: &'a Self) -> impl Iterator<Item = &'a Topic> {
        self.0
            .keys()
            .filter(move |topic| other.0.contains_key(topic))
    }

    pub fn proximity_to(&self, other: &Self) -> Proximity {
        let mut priority_score = 0;
        let mut proximity_score = 0;
        for (subscription, interest_level) in self.iter() {
            if let Some(other_interest_level) = other.0.get(subscription) {
                proximity_score += 1;
                priority_score += interest_level.priority_score(*other_interest_level);
            }
        }
        Proximity {
            proximity: ProximityScore(proximity_score),
            priority: PriorityScore(priority_score),
        }
    }
}