use super::Collector;
use crate::collector::SegmentCollector;
use crate::{DocId, Score, SegmentOrdinal, SegmentReader};
pub struct Count;
impl Collector for Count {
type Fruit = usize;
type Child = SegmentCountCollector;
fn for_segment(
&self,
_: SegmentOrdinal,
_: &SegmentReader,
) -> crate::Result<SegmentCountCollector> {
Ok(SegmentCountCollector::default())
}
fn requires_scoring(&self) -> bool {
false
}
fn merge_fruits(&self, segment_counts: Vec<usize>) -> crate::Result<usize> {
Ok(segment_counts.into_iter().sum())
}
}
#[derive(Default)]
pub struct SegmentCountCollector {
count: usize,
}
impl SegmentCollector for SegmentCountCollector {
type Fruit = usize;
fn collect(&mut self, _: DocId, _: Score) {
self.count += 1;
}
fn harvest(self) -> usize {
self.count
}
}
#[cfg(test)]
mod tests {
use super::{Count, SegmentCountCollector};
use crate::collector::{Collector, SegmentCollector};
#[test]
fn test_count_collect_does_not_requires_scoring() {
assert!(!Count.requires_scoring());
}
#[test]
fn test_segment_count_collector() {
{
let count_collector = SegmentCountCollector::default();
assert_eq!(count_collector.harvest(), 0);
}
{
let mut count_collector = SegmentCountCollector::default();
count_collector.collect(0u32, 1.0);
assert_eq!(count_collector.harvest(), 1);
}
{
let mut count_collector = SegmentCountCollector::default();
count_collector.collect(0u32, 1.0);
assert_eq!(count_collector.harvest(), 1);
}
{
let mut count_collector = SegmentCountCollector::default();
count_collector.collect(0u32, 1.0);
count_collector.collect(1u32, 1.0);
assert_eq!(count_collector.harvest(), 2);
}
}
}