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It's a simple Ruby gem for in-memory cache.

First, install it:

```bash
$ gem install zache
```

Then, use it like this

```ruby
require 'zache'
zache = Zache.new
# Expires in 5 minutes
v = zache.get(:count, lifetime: 5 * 60) { expensive() }
```

By default `Zache` is thread-safe. It locks the entire cache on each
`get` call. You turn that off by using `sync` argument:

```ruby
zache = Zache.new(sync: false)
v = zache.get(:count) { expensive() }
```

You may use "dirty" mode, which will return you an expired value, while
calculation is waiting. Say, you have something in the cache, but it's
expired. Then, you call `get` with a long running block. The thread waits,
while another one calls `get` again. That second thread won't wait, but will
receive what's left in the cache. This is a very convenient mode for situations
when you don't really care about data accuracy, but performance is an issue.

That's it.

# How to contribute

Read [these guidelines](https://www.yegor256.com/2014/04/15/github-guidelines.html).
Make sure you build is green before you contribute
your pull request. You will need to have [Ruby](https://www.ruby-lang.org/en/) 2.3+ and
[Bundler](https://bundler.io/) installed. Then:

```
$ bundle update
$ rake
```

If it's clean and you don't see any error messages, submit your pull request.

# License

(The MIT License)

Copyright (c) 2018 Yegor Bugayenko

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the 'Software'), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.