//! App state library with cache
//!
//! This crate provides functionality to store data and persists to filesystem
//! automatically. The main goal is to have a single object to query for app
//! state and to be able to modify this state.
//!
//! It also provides a simple signaler to be able to subscribe to update /delete
//! signals and perform custom operations on cache model modification.
//!
//! To store the information we use a key-value storage so each model should
//! provide a unique key that identify it. Use NoSQL schema techniques to add
//! relations between models using the key and query easily.
//!
//! The basic `Cache` object uses LMDB as storage so you can access to the same
//! cache from different threads or process.
//!
//! # Basic Usage
//!
//! The simpler way to use is implementing the `Model` trait for your struct,
//! so you can `get`, `store` and `delete`.
//!
//! ```ignore
//! use mdl::Cache;
//! use mdl::Model;
//! use mdl::Continue;
//!
//! use serde::{Deserialize, Serialize};
//!
//! #[derive(Serialize, Deserialize, Debug)]
//! struct A {
//!     pub p1: String,
//!     pub p2: u32,
//! }
//! impl Model for A {
//!     fn key(&self) -> String {
//!         format!("{}:{}", self.p1, self.p2)
//!     }
//! }
//!
//! fn main() {
//!     // initializing the cache. This str will be the fs persistence path
//!     let db = "/tmp/mydb.lmdb";
//!     let cache = Cache::new(db).unwrap();
//!
//!     // create a new *object* and storing in the cache
//!     let a = A{ p1: "hello".to_string(), p2: 42 };
//!     let r = a.store(&cache);
//!     assert!(r.is_ok());
//!
//!     // querying the cache by key and getting a new *instance*
//!     let a1: A = A::get(&cache, "hello:42").unwrap();
//!     assert_eq!(a1.p1, a.p1);
//!     assert_eq!(a1.p2, a.p2);
//! }
//! ```
//!
//! # Signals
//!
//! To allow easy notifications of changes in the cache, this crate
//! provides a signal system and the `Model` trait provides `store_sig`
//! and `delete_sig` that store or delete and then emit the corresponding
//! signal.
//!
//! There's two signalers implemented, one that can be `Send` between
//! threads and another one that should be in the same thread all the time
//! this allow us to register callbacks for signals and that callbacks
//! should implement `Send` for the `SignalerAsync`.
//!
//! ## Example
//!
//! ```ignore
//! use mdl::SigType;
//! use mdl::SignalerAsync;
//! use mdl::Cache;
//! use mdl::Model;
//!
//! use serde::{Deserialize, Serialize};
//!
//! use std::sync::{Arc, Mutex};
//! use std::{thread, time};
//!
//! #[derive(Serialize, Deserialize, Debug)]
//! struct B {
//!     pub id: u32,
//!     pub complex: Vec<String>,
//! }
//! impl Model for B {
//!     fn key(&self) -> String {
//!         format!("b:{}", self.id)
//!     }
//! }
//!
//! fn main() {
//!     let db = "/tmp/test.lmdb";
//!     let cache = Cache::new(db).unwrap();
//!     // using the async signaler that run in other thread
//!     let sig = SignalerAsync::new();
//!     // starting the signaler loop, this can be stoped
//!     // calling sig.stop() or when the signaler drops
//!     sig.signal_loop();
//!
//!     let up_c = Arc::new(Mutex::new(0));
//!     let rm_c = Arc::new(Mutex::new(0));
//!     let counter = Arc::new(Mutex::new(0));
//!
//!     let c1 = up_c.clone();
//!     let c2 = rm_c.clone();
//!     let c3 = counter.clone();
//!
//!     // Subscribing to the "b" signal, that's emited always
//!     // that an object which key starting with "b" is modified.
//!     // We're using the SignalerAsync so this callback will
//!     // be called in a different thread, for that reason we're
//!     // pasing Arc<Mutex<T>> to be able to modify the counters
//!     let _id = sig.subscribe("b", Box::new(move |sig| {
//!         match sig.type_ {
//!             SigType::Update => *c1.lock().unwrap() += 1,
//!             SigType::Delete => *c2.lock().unwrap() += 1,
//!         };
//!
//!         *c3.lock().unwrap() += 1;
//!     }));
//!
//!     let b = B{ id: 1, complex: vec![] };
//!     // we use the store_sig instead the store to emit the
//!     // corresponding signal, if we use the store, the callback
//!     // wont be called.
//!     let r = b.store_sig(&cache, &sig);
//!     assert!(r.is_ok());
//!
//!     let b = B{ id: 2, complex: vec![] };
//!     let r = b.store_sig(&cache, &sig);
//!     assert!(r.is_ok());
//!
//!     let r = b.delete_sig(&cache, &sig);
//!     assert!(r.is_ok());
//!
//!     // waiting for signal to come
//!     let ten_millis = time::Duration::from_millis(10);
//!     thread::sleep(ten_millis);
//!
//!     assert_eq!(*up_c.lock().unwrap(), 2);
//!     assert_eq!(*rm_c.lock().unwrap(), 1);
//!     assert_eq!(*counter.lock().unwrap(), 3);
//! }
//! ```
//!
//! You can use the `Signaler` without a `Model`, it's possible to emit custom
//! signals and subscribe to that signals, for example:
//!
//! ```ignore
//! use mdl::SigType;
//! use mdl::Signaler;
//! use mdl::SignalerAsync;
//! use std::{thread, time};
//!
//! fn main() {
//!     let sig = SignalerAsync::new();
//!     sig.signal_loop();
//!
//!     let _id = sig.subscribe("my signal", Box::new(move |sig| {
//!         println!("my signal is called");
//!     }));
//!
//!     let _ = sig.emit(SigType::Update, "my signal");
//!
//!     // waiting for signal to come
//!     let ten_millis = time::Duration::from_millis(10);
//!     thread::sleep(ten_millis);
//! }
//! ```

pub mod store;
pub mod cache;
pub mod bcache;
pub mod model;
pub mod signal;

pub use crate::store::Store;
pub use crate::store::Continue;
pub use cache::Cache;
pub use model::Model;

pub use bcache::Cache as BCache;

pub use crate::signal::Signaler;
pub use crate::signal::SignalerAsync;
pub use crate::signal::SignalerSync;
pub use crate::signal::Signal;
pub use crate::signal::SigType;