incremental-query 0.2.0

#![feature(macro_metavar_expr)]
#![doc = include_str!("../README.md")]

use siphasher::sip128::SipHasher13;

mod context;
mod generation;
mod query;
mod query_parameter;
mod storage;

pub use incremental_query_macros::*;

pub use context::Context;
pub use query_parameter::QueryParameter;
pub use storage::Storage;

// used in macros, hidden to the user
#[doc(hidden)]
pub use query::{ErasedQueryRun, Query, QueryMode};
#[doc(hidden)]
pub use query_parameter::TypeErasedQueryParam;

pub type QueryHasher = SipHasher13;

#[cfg(test)]
pub fn log() {
    use tracing_subscriber::EnvFilter;

    let format = tracing_subscriber::fmt::format()
        .without_time()
        .with_source_location(false);

    tracing_subscriber::fmt()
        .event_format(format)
        .with_env_filter(EnvFilter::from_default_env())
        .try_init()
        .ok();
}

#[cfg(test)]
mod tests {
    use crate::log;

    // #[test]
    // fn query_mode() {
    //     define_query! {
    //         #[rerun(always)]
    //         fn always<'cx>(_cx: &Context<'cx>, _inp: &())  {}
    //         fn cache<'cx>(_cx: &Context<'cx>, _inp: &())  {}
    //         #[rerun(generation)]
    //         fn generation<'cx>(_cx: &Context<'cx>, _inp: &())  {}
    //     }
    //     log();
    //
    //     assert_eq!(always.mode(), QueryMode::Always);
    //     assert_eq!(generation.mode(), QueryMode::Generation);
    //     assert_eq!(cache.mode(), QueryMode::Cache);
    // }

    use std::{
        cell::{Cell, RefCell},
        collections::VecDeque,
        hash::Hash,
        ops::Deref,
        rc::Rc,
    };

    use crate::{
        query, query_parameter::QueryParameter, rerun, storage::Storage, Context, QueryHasher,
    };
    use rand::{thread_rng, Rng};

    pub mod incremental_query {
        pub use crate::*;
    }

    #[derive(Clone)]
    struct Counter(pub u64, Rc<Cell<usize>>);
    impl Counter {
        // create a new counter that counts how many times it has been add() ed to
        // The metric itself is not hashed and is thus not compared for equality
        // while calling queries
        pub fn new(i: u64) -> Self {
            Self(i, Default::default())
        }

        pub fn add(&self) {
            self.1.set(self.1.get() + 1);
        }

        pub fn get(&self) -> usize {
            self.1.get()
        }
    }

    #[derive(Clone)]
    struct ReturnInOrder<T> {
        data: Rc<RefCell<VecDeque<T>>>,
        id: u64,
    }

    impl<T> ReturnInOrder<T> {
        fn new(inp: impl IntoIterator<Item = T>, id: u64) -> Self {
            Self {
                data: Rc::new(RefCell::new(inp.into_iter().collect())),
                id,
            }
        }

        fn is_empty(&self) -> bool {
            self.data.borrow().len() == 0
        }

        fn next(&self) -> T {
            self.data.borrow_mut().pop_front().expect("empty")
        }
    }

    impl QueryParameter for Counter {
        fn hash_stable(&self, hasher: &mut QueryHasher) {
            self.0.hash(hasher);
        }
    }
    impl<T: Clone + 'static> QueryParameter for ReturnInOrder<T> {
        fn hash_stable(&self, hasher: &mut QueryHasher) {
            self.id.hash(hasher);
        }
    }

    #[test]
    fn call_once() {
        #[query]
        fn test<'cx>(_cx: &Context<'cx>, input: &Counter) {
            input.add();
        }

        log();
        let storage = Storage::new();

        let ctr = Counter::new(0);
        let cx = Context::new(&storage);
        test(&cx, ctr.clone());
        assert_eq!(ctr.get(), 1);
    }

    #[test]
    fn call_twice() {
        #[query]
        fn called_twice<#[lt] 'a>(_cx: &Context<'a>, input: &Counter) {
            input.add();
        }
        log();

        let storage = Storage::new();

        let ctr = Counter::new(0);
        let cx = Context::new(&storage);

        called_twice(&cx, ctr.clone());
        called_twice(&cx, ctr.clone());
        assert_eq!(ctr.get(), 1);
    }

    #[test]
    fn impure_rerun() {
        #[query]
        #[rerun(always)]
        fn random<'cx>(_cx: &Context<'cx>) -> u64 {
            thread_rng().gen_range(0..u64::MAX)
        }

        #[query]
        fn depends_on_impure<'cx>(cx: &Context<'cx>, inp: &Counter) {
            inp.add();
            let _dep = random(cx);
        }

        log();

        let storage = Storage::new();

        let ctr = Counter::new(0);
        let cx = Context::new(&storage);
        depends_on_impure(&cx, ctr.clone());
        depends_on_impure(&cx, ctr.clone());

        assert_eq!(ctr.get(), 2);
    }

    #[test]
    fn test_intvalue() {
        #[query]
        #[rerun(always)]
        fn intvalue<'cx>(_cx: &Context<'cx>, r: &ReturnInOrder<i64>) -> i64 {
            r.next()
        }

        #[query]
        fn sign_of<'cx>(cx: &Context<'cx>, r: &ReturnInOrder<i64>, c2: &Counter) -> bool {
            let v = intvalue(cx, r.clone());
            c2.add();

            v.is_positive()
        }

        #[query]
        fn some_other_query<'cx>(
            cx: &Context<'cx>,
            r: &ReturnInOrder<i64>,
            c1: &Counter,
            c2: &Counter,
        ) {
            c1.add();
            sign_of(cx, r.clone(), c2.clone());
        }
        log();

        let storage = Storage::new();

        // note: 2000 is here twice since initvalue is actuall run three times in total.
        // * once for some_other_query's first invocation
        // * once to figure out that some_other_query's second invocation
        // * once to actually run `sign_of` a second time after we figured out that we have to.
        // TODO: can this be optimized?
        let order = ReturnInOrder::new(vec![1000, 2000, 2000], 1);
        let counter1 = Counter::new(1);
        let counter2 = Counter::new(2);
        let cx = Context::new(&storage);

        some_other_query(&cx, order.clone(), counter1.clone(), counter2.clone());
        some_other_query(&cx, order.clone(), counter1.clone(), counter2.clone());

        assert!(order.is_empty());
        assert_eq!(counter1.get(), 1);
        assert_eq!(counter2.get(), 2);
    }

    #[test]
    fn test_intvalue_generational() {
        #[query]
        #[rerun(generation)]
        fn intvalue<'cx>(_cx: &Context<'cx>, r: &ReturnInOrder<i64>) -> i64 {
            r.next()
        }

        #[query]
        fn sign_of<'cx>(cx: &Context<'cx>, r: &ReturnInOrder<i64>, c2: &Counter) -> bool {
            let v = intvalue(cx, r.clone());
            c2.add();

            v.is_positive()
        }

        #[query]
        fn some_other_query<'cx>(
            cx: &Context<'cx>,
            r: &ReturnInOrder<i64>,
            c1: &Counter,
            c2: &Counter,
        ) {
            c1.add();
            sign_of(cx, r.clone(), c2.clone());
        }
        log();

        let storage = Storage::new();

        // now 2000 is there only once because the query is generational, and the first run in the
        // 2nd generation can be cached.
        let order = ReturnInOrder::new(vec![1000, 2000], 1);
        let counter1 = Counter::new(1);
        let counter2 = Counter::new(2);
        let cx = Context::new(&storage);

        some_other_query(&cx, order.clone(), counter1.clone(), counter2.clone());
        cx.next_generation();
        some_other_query(&cx, order.clone(), counter1.clone(), counter2.clone());

        assert!(order.is_empty());
        assert_eq!(counter1.get(), 1);
        assert_eq!(counter2.get(), 2);
    }

    #[test]
    fn test_intvalue_many_generation() {
        #[query]
        #[rerun(generation)]
        fn intvalue<'cx>(_cx: &Context<'cx>, r: &ReturnInOrder<i64>) -> i64 {
            r.next()
        }

        #[query]
        fn sign_of<'cx>(cx: &Context<'cx>, r: &ReturnInOrder<i64>, c2: &Counter) -> bool {
            let v = intvalue(cx, r.clone());
            c2.add();

            v.is_positive()
        }

        #[query]
        fn some_other_query<'cx>(
            cx: &Context<'cx>,
            r: &ReturnInOrder<i64>,
            c1: &Counter,
            c2: &Counter,
        ) {
            c1.add();
            sign_of(cx, r.clone(), c2.clone());
        }
        log();

        let storage = Storage::new();

        // now 2000 is there only once because the query is generational, and the first run in the
        // 2nd generation can be cached.
        let order = ReturnInOrder::new(vec![1000, 2000, 3000], 1);
        let counter1 = Counter::new(1);
        let counter2 = Counter::new(2);
        let cx = Context::new(&storage);

        some_other_query(&cx, order.clone(), counter1.clone(), counter2.clone());
        cx.next_generation();
        some_other_query(&cx, order.clone(), counter1.clone(), counter2.clone());
        cx.next_generation();
        some_other_query(&cx, order.clone(), counter1.clone(), counter2.clone());

        assert!(order.is_empty());
        assert_eq!(counter1.get(), 1);
        assert_eq!(counter2.get(), 3);
    }

    #[test]
    fn test_intvalue_assume_pure_wrong() {
        #[query]
        fn intvalue<'cx>(_cx: &Context<'cx>, r: &ReturnInOrder<i64>) -> i64 {
            r.next()
        }

        #[query]
        fn sign_of<'cx>(cx: &Context<'cx>, r: &ReturnInOrder<i64>, c2: &Counter) -> bool {
            let v = intvalue(cx, r.clone());
            c2.add();

            v.is_positive()
        }

        #[query]
        fn some_other_query<'cx>(
            cx: &Context<'cx>,
            r: &ReturnInOrder<i64>,
            c1: &Counter,
            c2: &Counter,
        ) {
            c1.add();
            sign_of(cx, r.clone(), c2.clone());
        }
        log();

        let storage = Storage::new();

        // now 2000 is there only once because the query is generational, and the first run in the
        // 2nd generation can be cached.
        let order = ReturnInOrder::new(vec![1000, 2000], 1);
        let counter1 = Counter::new(1);
        let counter2 = Counter::new(2);
        let cx = Context::new(&storage);

        some_other_query(&cx, order.clone(), counter1.clone(), counter2.clone());
        some_other_query(&cx, order.clone(), counter1.clone(), counter2.clone());

        assert!(!order.is_empty());
        assert_eq!(counter1.get(), 1);
        assert_eq!(counter2.get(), 1);
    }

    #[test]
    fn conditional_query() {
        #[query]
        #[rerun(generation)]
        fn boolean_query<'cx>(_cx: &Context<'cx>, r: &ReturnInOrder<bool>) -> bool {
            r.next()
        }

        #[query]
        fn one<'cx>(_cx: &Context<'cx>) -> u64 {
            1
        }
        #[query]
        fn two<'cx>(_cx: &Context<'cx>, c: &Counter) -> u64 {
            c.add();
            2
        }

        #[query]
        fn conditional<'cx>(cx: &Context<'cx>, r: &ReturnInOrder<bool>, c: &Counter) -> u64 {
            if *boolean_query(cx, r.clone()) {
                *one(cx)
            } else {
                *two(cx, c.clone())
            }
        }

        log();

        let storage = Storage::new();
        let order = ReturnInOrder::new(vec![true, false], 1);
        let counter = Counter::new(0);
        let cx = Context::new(&storage);

        assert_eq!(conditional(&cx, order.clone(), counter.clone()), &1);
        cx.next_generation();
        assert_eq!(conditional(&cx, order.clone(), counter.clone()), &2);
        assert_eq!(conditional(&cx, order.clone(), counter.clone()), &2);
        assert_eq!(conditional(&cx, order.clone(), counter.clone()), &2);
        assert_eq!(counter.get(), 1);
        assert!(order.is_empty())
    }

    #[test]
    #[should_panic]
    fn cycle() {
        #[query]
        fn cyclic<'cx>(cx: &Context<'cx>, r: &u64) -> bool {
            *cyclic(cx, *r)
        }

        log();

        let storage = Storage::new();
        let cx = Context::new(&storage);
        cyclic(&cx, 10);
    }

    #[test]
    #[should_panic]
    fn long_cycle() {
        #[query]
        fn e<'cx>(cx: &Context<'cx, i64>, r: &u64) -> bool {
            *a(cx, *r)
        }

        #[query]
        fn d<'cx>(cx: &Context<'cx, i64>, r: &u64) -> bool {
            *e(cx, *r)
        }

        #[query]
        fn c<'cx>(cx: &Context<'cx, i64>, r: &u64) -> bool {
            *d(cx, *r)
        }

        #[query]
        fn b<'cx>(cx: &Context<'cx, i64>, r: &u64) -> bool {
            *c(cx, *r)
        }

        #[query]
        fn a<'cx>(cx: &Context<'cx, i64>, r: &u64) -> bool {
            *b(cx, *r)
        }
        log();

        let storage = Storage::new();
        let cx = Context::with_data(&storage, 12);
        a(&cx, 10);
        assert_eq!(cx.deref(), &12);
    }

    #[test]
    fn garbage_collect() {
        #[query]
        fn value_dependent<'cx>(_cx: &Context<'cx>, r: &i64) -> i64 {
            r * 2
        }

        #[query]
        #[rerun(generation)]
        fn intvalue<'cx>(_cx: &Context<'cx>, r: &ReturnInOrder<i64>) -> i64 {
            r.next()
        }

        #[query]
        fn sign_of<'cx>(cx: &Context<'cx>, r: &ReturnInOrder<i64>) -> bool {
            let v = intvalue(cx, r.clone());
            value_dependent(cx, *v).is_positive()
        }

        #[query]
        fn some_other_query<'cx>(cx: &Context<'cx>, r: &ReturnInOrder<i64>) {
            sign_of(cx, r.clone());
        }
        log();

        const N: i64 = 1000;

        let storage = Storage::new();

        let mut data = Vec::new();
        for i in 0..N {
            data.push(i * 1000);
        }

        // now 2000 is there only once because the query is generational, and the first run in the
        // 2nd generation can be cached.
        let order = ReturnInOrder::new(data, 1);
        let cx = Context::new(&storage);

        for _ in 0..N {
            some_other_query(&cx, order.clone());
            cx.next_generation();
        }
        assert!(order.is_empty());

        let new_storage = Storage::new();

        tracing::info!("{}", cx.size());
        let res = cx.gc(&new_storage);
        drop(storage);
        tracing::info!("{}", res.size());
    }

    #[test]
    fn impure_cache_rerun() {
        #[query]
        #[rerun(always)]
        fn random<'cx>(_cx: &Context<'cx>) -> u64 {
            thread_rng().gen_range(0..u64::MAX)
        }

        #[query]
        fn depends_on_impure<'cx>(cx: &Context<'cx>, inp: &Counter) {
            inp.add();
            let _dep = random(&cx);
        }

        log();

        let storage = Storage::new();

        let ctr = Counter::new(0);
        let cx = Context::new(&storage);
        depends_on_impure(&cx, ctr.clone());
        depends_on_impure(&cx, ctr.clone());
        depends_on_impure(&cx, ctr.clone());
        depends_on_impure(&cx, ctr.clone());
        depends_on_impure(&cx, ctr.clone());

        assert_eq!(ctr.get(), 5);
    }

    #[test]
    fn cache_off() {
        /// Look! this query is even documented!
        #[query]
        #[inline(always)] // that's not rerun!
        fn random<'cx>(_cx: &Context<'cx>) -> u64 {
            thread_rng().gen_range(0..u64::MAX)
        }

        #[query]
        fn depends_on_impure<'cx>(cx: &Context<'cx>, inp: &Counter) {
            inp.add();
            let _dep = random(cx);
        }

        log();

        let storage = Storage::new();

        let ctr = Counter::new(0);
        let cx = Context::new(&storage);
        cx.set_cache_enabled(false);
        depends_on_impure(&cx, ctr.clone());
        depends_on_impure(&cx, ctr.clone());
        depends_on_impure(&cx, ctr.clone());
        depends_on_impure(&cx, ctr.clone());
        depends_on_impure(&cx, ctr.clone());

        assert_eq!(ctr.get(), 5);

        let ctr = Counter::new(0);
        let cx = Context::new(&storage);
        cx.set_cache_enabled(true);
        depends_on_impure(&cx, ctr.clone());
        depends_on_impure(&cx, ctr.clone());
        depends_on_impure(&cx, ctr.clone());
        depends_on_impure(&cx, ctr.clone());
        depends_on_impure(&cx, ctr.clone());

        assert_eq!(ctr.get(), 1);
    }
}