use async_std::prelude::*;
use async_std::sync::{Arc, Mutex};
use async_std::task;
use async_trait::async_trait;
use dataloader::cached::Loader;
use dataloader::BatchFn;
use std::collections::{HashMap, HashSet};
use std::thread;
struct MyLoadFn;
#[async_trait]
impl BatchFn<usize, usize> for MyLoadFn {
type Error = ();
fn max_batch_size(&self) -> usize {
4
}
async fn load(&self, keys: &[usize]) -> HashMap<usize, Result<usize, Self::Error>> {
keys.iter()
.map(|v| (v.clone(), Ok(v.clone())))
.collect::<HashMap<_, _>>()
}
}
#[derive(Clone)]
struct Object(usize);
#[async_trait]
impl BatchFn<usize, Object> for MyLoadFn {
type Error = ();
fn max_batch_size(&self) -> usize {
4
}
async fn load(&self, keys: &[usize]) -> HashMap<usize, Result<Object, Self::Error>> {
keys.iter()
.map(|v| (v.clone(), Ok(Object(v.clone()))))
.collect::<HashMap<_, _>>()
}
}
#[test]
fn assert_kinds() {
fn _assert_send<T: Send>() {}
fn _assert_sync<T: Sync>() {}
fn _assert_clone<T: Clone>() {}
_assert_send::<Loader<usize, usize, (), MyLoadFn>>();
_assert_sync::<Loader<usize, usize, (), MyLoadFn>>();
_assert_clone::<Loader<usize, usize, (), MyLoadFn>>();
_assert_send::<Loader<usize, Object, (), MyLoadFn>>();
_assert_sync::<Loader<usize, Object, (), MyLoadFn>>();
_assert_clone::<Loader<usize, Object, (), MyLoadFn>>();
}
#[derive(Clone)]
struct LoadFnWithHistory<K> {
loaded_keys: Arc<Mutex<HashSet<K>>>,
max_batch_loaded: Arc<Mutex<usize>>,
}
#[async_trait]
impl BatchFn<usize, usize> for LoadFnWithHistory<usize> {
type Error = ();
fn max_batch_size(&self) -> usize {
4
}
async fn load(&self, keys: &[usize]) -> HashMap<usize, Result<usize, Self::Error>> {
let mut loaded_keys = self.loaded_keys.lock().await;
let mut max_batch_loaded = self.max_batch_loaded.lock().await;
if keys.len() > *max_batch_loaded {
*max_batch_loaded = keys.len();
}
for k in keys {
if loaded_keys.contains(k) {
panic!("already loaded, loader should not request same key");
}
}
keys.iter()
.map(|v| {
loaded_keys.insert(v.clone());
(v.clone(), Ok(v.clone()))
})
.collect::<HashMap<_, _>>()
}
}
#[test]
fn test_load() {
let mut i = 0;
while i < 1000 {
let load_fn = LoadFnWithHistory {
loaded_keys: Arc::new(Mutex::new(HashSet::new())),
max_batch_loaded: Arc::new(Mutex::new(0)),
};
let loader = Loader::new(load_fn.clone());
let l1 = loader.clone();
let h1 = thread::spawn(move || {
let r1 = l1.load(1);
let r2 = l1.load(2);
let r3 = l1.load(3);
let r4 = l1.load_many(vec![2, 3, 4, 5, 6, 7, 8]);
let f = r1.join(r2).join(r3).join(r4);
let fv = task::block_on(f);
let (((_v1, _v2), _v3), v4) = fv;
let mut v4_keys = v4.keys().cloned().collect::<Vec<_>>();
v4_keys.sort();
assert_eq!(vec![2, 3, 4, 5, 6, 7, 8], v4_keys);
});
let l2 = loader.clone();
let h2 = thread::spawn(move || {
let r1 = l2.load(1);
let r2 = l2.load(2);
let r3 = l2.load(3);
let r4 = l2.load(4);
let f = r1.join(r2).join(r3).join(r4);
let _fv = task::block_on(f);
});
let l3 = loader.clone();
let h3 = thread::spawn(move || {
let r1 = l3.load_many(vec![12, 13, 14, 1, 2, 3, 4]);
let r2 = l3.load_many(vec![1, 2, 3, 4, 5, 6, 7]);
let r3 = l3.load_many(vec![9, 10, 11, 12, 13, 14]);
let f = r1.join(r2).join(r3);
let fv = task::block_on(f);
let ((v1, v2), v3) = fv;
let mut v1_keys = v1.keys().cloned().collect::<Vec<_>>();
v1_keys.sort();
assert_eq!(vec![1, 2, 3, 4, 12, 13, 14], v1_keys);
let mut v2_keys = v2.keys().cloned().collect::<Vec<_>>();
v2_keys.sort();
assert_eq!(vec![1, 2, 3, 4, 5, 6, 7], v2_keys);
let mut v3_keys = v3.keys().cloned().collect::<Vec<_>>();
v3_keys.sort();
assert_eq!(vec![9, 10, 11, 12, 13, 14], v3_keys);
});
h1.join().unwrap();
h2.join().unwrap();
h3.join().unwrap();
i += 1;
let max_batch_size = load_fn.max_batch_size();
let max_batch_loaded = task::block_on(load_fn.max_batch_loaded.lock());
assert!(*max_batch_loaded > 1);
assert!(
*max_batch_loaded <= max_batch_size,
"max_batch_loaded({}) <= max_batch_size({})",
*max_batch_loaded,
max_batch_size
);
}
}
#[test]
fn test_load_many() {
let mut i = 0;
while i < 10 {
let load_fn = LoadFnWithHistory {
loaded_keys: Arc::new(Mutex::new(HashSet::new())),
max_batch_loaded: Arc::new(Mutex::new(0)),
};
let loader = Loader::new(load_fn.clone());
let r = loader.load_many(vec![2, 3, 4, 5, 6, 7, 8]);
let _fv = task::block_on(r);
i += 1;
let max_batch_size = load_fn.max_batch_size();
let max_batch_loaded = task::block_on(load_fn.max_batch_loaded.lock());
assert!(*max_batch_loaded > 1);
assert!(
*max_batch_loaded <= max_batch_size,
"max_batch_loaded({}) <= max_batch_size({})",
*max_batch_loaded,
max_batch_size
);
}
}