safe_vault 0.12.0

// Copyright 2016 MaidSafe.net limited.
//
// This SAFE Network Software is licensed to you under (1) the MaidSafe.net Commercial License,
// version 1.0 or later, or (2) The General Public License (GPL), version 3, depending on which
// licence you accepted on initial access to the Software (the "Licences").
//
// By contributing code to the SAFE Network Software, or to this project generally, you agree to be
// bound by the terms of the MaidSafe Contributor Agreement, version 1.0.  This, along with the
// Licenses can be found in the root directory of this project at LICENSE, COPYING and CONTRIBUTOR.
//
// Unless required by applicable law or agreed to in writing, the SAFE Network Software distributed
// under the GPL Licence is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.
//
// Please review the Licences for the specific language governing permissions and limitations
// relating to use of the SAFE Network Software.

use lru_time_cache::LruCache;
use routing::{Data, DataIdentifier, ImmutableData, Request, Response, XorName};
use routing::Cache as RoutingCache;
use std::cell::RefCell;
use std::time::Duration;

const CACHE_CAPACITY: usize = 1000;
const CACHE_EXPIRY_DURATION_SECS: u64 = 60 * 60;

pub struct Cache {
    store: RefCell<LruCache<XorName, ImmutableData>>,
}

impl Cache {
    pub fn new() -> Self {
        Cache {
            store: RefCell::new(LruCache::with_expiry_duration_and_capacity(
                                    Duration::from_secs(CACHE_EXPIRY_DURATION_SECS),
                                    CACHE_CAPACITY)),
        }
    }
}

impl RoutingCache for Cache {
    fn get(&self, request: &Request) -> Option<Response> {
        if let Request::Get(DataIdentifier::Immutable(name), message_id) = *request {
            self.store
                .borrow_mut()
                .get(&name)
                .map(|data| Response::GetSuccess(Data::Immutable(data.clone()), message_id))
        } else {
            None
        }
    }

    fn put(&self, response: Response) {
        if let Response::GetSuccess(Data::Immutable(data), _) = response {
            let _ = self.store.borrow_mut().insert(*data.name(), data);
        }
    }
}

#[cfg(test)]
mod tests {
    use routing::{Data, ImmutableData, MessageId, Request, Response};
    use routing::Cache as RoutingCache;
    use super::Cache;

    #[test]
    fn put_and_get() {
        let cache = Cache::new();

        let data = "hello world".bytes().collect();
        let data = Data::Immutable(ImmutableData::new(data));
        let response_message_id = MessageId::new();

        let response = Response::GetSuccess(data.clone(), response_message_id);
        cache.put(response);

        let request_message_id = MessageId::new();
        let request = Request::Get(data.identifier(), request_message_id);

        match cache.get(&request) {
            Some(Response::GetSuccess(cached_data, cached_message_id)) => {
                assert_eq!(cached_data, data);
                assert_eq!(cached_message_id, request_message_id);
            }
            _ => panic!("unexpected cached value"),
        }
    }
}