tower-sesh 0.1.0-alpha.3

A Tower middleware for strongly typed, efficient sessions.
Documentation 
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

use std::{collections::HashMap, marker::PhantomData, sync::Arc};

use async_trait::async_trait;
use parking_lot::Mutex;
use tower_sesh_core::{
    store::{Error, SessionStoreImpl, Ttl},
    Record, SessionKey,
};

pub use tower_sesh_core::SessionStore;

type Result<T, E = Error> = std::result::Result<T, E>;

#[derive(Clone)]
pub struct MemoryStore<T>(Arc<Mutex<HashMap<SessionKey, Record<T>>>>);

impl<T> Default for MemoryStore<T> {
    fn default() -> Self {
        let store = HashMap::new();
        MemoryStore(Arc::new(Mutex::new(store)))
    }
}

impl<T> MemoryStore<T> {
    pub fn new() -> Self {
        Self::default()
    }
}

impl<T> SessionStore<T> for MemoryStore<T> where T: 'static + Send + Sync + Clone {}

#[async_trait]
impl<T> SessionStoreImpl<T> for MemoryStore<T>
where
    T: 'static + Send + Sync + Clone,
{
    async fn create(&self, data: &T, ttl: Ttl) -> Result<SessionKey> {
        let session_key = SessionKey::generate();
        self.update(&session_key, data, ttl).await?;
        Ok(session_key)
    }

    async fn load(&self, session_key: &SessionKey) -> Result<Option<Record<T>>> {
        let store_guard = self.0.lock();
        Ok(store_guard.get(session_key).cloned())
    }

    async fn update(&self, session_key: &SessionKey, data: &T, ttl: Ttl) -> Result<()> {
        let record = Record::new(data.clone(), ttl);
        self.0.lock().insert(session_key.clone(), record);
        Ok(())
    }

    async fn update_ttl(&self, session_key: &SessionKey, ttl: Ttl) -> Result<()> {
        if let Some(record) = self.0.lock().get_mut(session_key) {
            record.ttl = ttl;
        }
        Ok(())
    }

    async fn delete(&self, session_key: &SessionKey) -> Result<()> {
        self.0.lock().remove(session_key);
        Ok(())
    }
}

pub struct CachingStore<T, Cache: SessionStore<T>, Store: SessionStore<T>> {
    cache: Cache,
    store: Store,
    _marker: PhantomData<fn() -> T>,
}

impl<T, Cache: SessionStore<T>, Store: SessionStore<T>> CachingStore<T, Cache, Store> {
    pub fn from_cache_and_store(cache: Cache, store: Store) -> Self {
        Self {
            cache,
            store,
            _marker: PhantomData,
        }
    }
}

impl<T, Cache: SessionStore<T>, Store: SessionStore<T>> SessionStore<T>
    for CachingStore<T, Cache, Store>
where
    T: 'static + Send + Sync,
{
}

#[async_trait]
impl<T, Cache: SessionStore<T>, Store: SessionStore<T>> SessionStoreImpl<T>
    for CachingStore<T, Cache, Store>
where
    T: 'static + Send + Sync,
{
    async fn create(&self, data: &T, ttl: Ttl) -> Result<SessionKey> {
        let session_key = self.store.create(data, ttl).await?;
        self.cache.update(&session_key, data, ttl).await?;

        Ok(session_key)
    }

    async fn load(&self, session_key: &SessionKey) -> Result<Option<Record<T>>> {
        match self.cache.load(session_key).await {
            Ok(Some(record)) => Ok(Some(record)),
            Ok(None) | Err(_) => {
                let record = self.store.load(session_key).await?;

                if let Some(record) = record.as_ref() {
                    let _ = self
                        .cache
                        .update(session_key, &record.data, record.ttl)
                        .await;
                }

                Ok(record)
            }
        }
    }

    async fn update(&self, session_key: &SessionKey, data: &T, ttl: Ttl) -> Result<()> {
        let store_fut = self.store.update(session_key, data, ttl);
        let cache_fut = self.cache.update(session_key, data, ttl);

        futures::try_join!(store_fut, cache_fut)?;

        Ok(())
    }

    async fn update_ttl(&self, session_key: &SessionKey, ttl: Ttl) -> Result<()> {
        let store_fut = self.store.update_ttl(session_key, ttl);
        let cache_fut = self.cache.update_ttl(session_key, ttl);

        futures::try_join!(store_fut, cache_fut)?;

        Ok(())
    }

    async fn delete(&self, session_key: &SessionKey) -> Result<()> {
        let store_fut = self.store.delete(session_key);
        let cache_fut = self.cache.delete(session_key);

        futures::try_join!(store_fut, cache_fut)?;

        Ok(())
    }
}