/
parallel_map.rs
222 lines (198 loc) · 6.42 KB
/
parallel_map.rs
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use crate::error::ChainResponse;
use crate::message::Messages;
use crate::transforms::chain::{TransformChain, TransformChainBuilder};
use crate::transforms::{
build_chain_from_config, Transform, TransformBuilder, TransformsConfig, Wrapper,
};
use anyhow::Result;
use async_trait::async_trait;
use futures::stream::{FuturesOrdered, FuturesUnordered};
use futures::task::{Context, Poll};
use futures::Stream;
use futures::StreamExt;
use itertools::Itertools;
use serde::Deserialize;
use std::future::Future;
use std::pin::Pin;
#[derive(Debug, Clone)]
pub struct ParallelMapBuilder {
chains: Vec<TransformChainBuilder>,
ordered: bool,
}
#[derive(Debug)]
pub struct ParallelMap {
chains: Vec<TransformChain>,
ordered: bool,
}
enum UOFutures<T: Future> {
Ordered(FuturesOrdered<T>),
Unordered(FuturesUnordered<T>),
}
impl<T> UOFutures<T>
where
T: Future,
{
pub fn new(ordered: bool) -> Self {
if ordered {
Self::Ordered(FuturesOrdered::new())
} else {
Self::Unordered(FuturesUnordered::new())
}
}
pub fn push(&mut self, future: T) {
match self {
UOFutures::Ordered(o) => o.push_back(future),
UOFutures::Unordered(u) => u.push(future),
}
}
}
impl<T> Stream for UOFutures<T>
where
T: Future,
{
type Item = T::Output;
fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
match self.get_mut() {
UOFutures::Ordered(o) => Pin::new(o).poll_next(cx),
UOFutures::Unordered(u) => Pin::new(u).poll_next(cx),
}
}
}
#[derive(Deserialize, Debug, Clone)]
pub struct ParallelMapConfig {
pub parallelism: u32,
pub chain: Vec<TransformsConfig>,
pub ordered_results: bool,
}
impl ParallelMapConfig {
pub async fn get_builder(&self) -> Result<TransformBuilder> {
let chain = build_chain_from_config("parallel_map_chain".into(), &self.chain).await?;
Ok(TransformBuilder::ParallelMap(ParallelMapBuilder {
chains: std::iter::repeat(chain)
.take(self.parallelism as usize)
.collect_vec(),
ordered: self.ordered_results,
}))
}
}
#[async_trait]
impl Transform for ParallelMap {
async fn transform<'a>(&'a mut self, message_wrapper: Wrapper<'a>) -> ChainResponse {
let mut results = Vec::with_capacity(message_wrapper.messages.len());
let mut message_iter = message_wrapper.messages.into_iter();
while message_iter.len() != 0 {
let mut future = UOFutures::new(self.ordered);
for chain in self.chains.iter_mut() {
if let Some(message) = message_iter.next() {
future.push(chain.process_request(
Wrapper::new_with_chain_name(
vec![message],
chain.name.clone(),
message_wrapper.local_addr,
),
"Parallel".to_string(),
));
}
}
// We do this gnarly functional chain to unwrap each individual result and pop an error on the first one
// then flatten it into one giant response.
results.extend(
future
.collect::<Vec<_>>()
.await
.into_iter()
.collect::<anyhow::Result<Vec<Messages>>>()
.into_iter()
.flat_map(|ms| ms.into_iter().flatten()),
);
}
Ok(results)
}
}
impl ParallelMapBuilder {
pub fn build(self) -> ParallelMap {
ParallelMap {
chains: self.chains.into_iter().map(|x| x.build()).collect(),
ordered: self.ordered,
}
}
fn get_name(&self) -> &'static str {
"ParallelMap"
}
pub fn validate(&self) -> Vec<String> {
let mut errors = self
.chains
.iter()
.flat_map(|chain| {
chain
.validate()
.iter()
.map(|x| format!(" {x}"))
.collect::<Vec<String>>()
})
.collect::<Vec<String>>();
if !errors.is_empty() {
errors.insert(0, format!("{}:", self.get_name()));
}
errors
}
pub fn is_terminating(&self) -> bool {
true
}
}
#[cfg(test)]
mod parallel_map_tests {
use crate::transforms::chain::TransformChainBuilder;
use crate::transforms::debug::printer::DebugPrinter;
use crate::transforms::null::NullSink;
use crate::transforms::parallel_map::ParallelMapBuilder;
use crate::transforms::TransformBuilder;
#[tokio::test]
async fn test_validate_invalid_chain() {
let chain_1 = TransformChainBuilder::new(
vec![
TransformBuilder::DebugPrinter(DebugPrinter::new()),
TransformBuilder::DebugPrinter(DebugPrinter::new()),
TransformBuilder::NullSink(NullSink::default()),
],
"test-chain-1".to_string(),
);
let chain_2 = TransformChainBuilder::new(vec![], "test-chain-2".to_string());
let transform = ParallelMapBuilder {
chains: vec![chain_1, chain_2],
ordered: true,
};
assert_eq!(
transform.validate(),
vec![
"ParallelMap:",
" test-chain-2:",
" Chain cannot be empty"
]
);
}
#[tokio::test]
async fn test_validate_valid_chain() {
let chain_1 = TransformChainBuilder::new(
vec![
TransformBuilder::DebugPrinter(DebugPrinter::new()),
TransformBuilder::DebugPrinter(DebugPrinter::new()),
TransformBuilder::NullSink(NullSink::default()),
],
"test-chain-1".to_string(),
);
let chain_2 = TransformChainBuilder::new(
vec![
TransformBuilder::DebugPrinter(DebugPrinter::new()),
TransformBuilder::DebugPrinter(DebugPrinter::new()),
TransformBuilder::NullSink(NullSink::default()),
],
"test-chain-2".to_string(),
);
let transform = ParallelMapBuilder {
chains: vec![chain_1, chain_2],
ordered: true,
};
assert_eq!(transform.validate(), Vec::<String>::new());
}
}