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mod pool;
use self::pool::{LeasedItem, Pool};
use crate::core::Segment;
use crate::directory::Directory;
use crate::directory::WatchHandle;
use crate::directory::META_LOCK;
use crate::Index;
use crate::Result;
use crate::Searcher;
use crate::SegmentReader;
use std::sync::Arc;
#[derive(Clone, Copy)]
pub enum ReloadPolicy {
Manual,
OnCommit,
}
#[derive(Clone)]
pub struct IndexReaderBuilder {
num_searchers: usize,
reload_policy: ReloadPolicy,
index: Index,
}
impl IndexReaderBuilder {
pub(crate) fn new(index: Index) -> IndexReaderBuilder {
IndexReaderBuilder {
num_searchers: num_cpus::get(),
reload_policy: ReloadPolicy::OnCommit,
index,
}
}
pub fn try_into(self) -> Result<IndexReader> {
let inner_reader = InnerIndexReader {
index: self.index,
num_searchers: self.num_searchers,
searcher_pool: Pool::new(),
};
inner_reader.reload()?;
let inner_reader_arc = Arc::new(inner_reader);
let watch_handle_opt: Option<WatchHandle>;
match self.reload_policy {
ReloadPolicy::Manual => {
watch_handle_opt = None;
}
ReloadPolicy::OnCommit => {
let inner_reader_arc_clone = inner_reader_arc.clone();
let callback = move || {
if let Err(err) = inner_reader_arc_clone.reload() {
error!(
"Error while loading searcher after commit was detected. {:?}",
err
);
}
};
let watch_handle = inner_reader_arc
.index
.directory()
.watch(Box::new(callback))?;
watch_handle_opt = Some(watch_handle);
}
}
Ok(IndexReader {
inner: inner_reader_arc,
watch_handle_opt,
})
}
pub fn reload_policy(mut self, reload_policy: ReloadPolicy) -> IndexReaderBuilder {
self.reload_policy = reload_policy;
self
}
pub fn num_searchers(mut self, num_searchers: usize) -> IndexReaderBuilder {
self.num_searchers = num_searchers;
self
}
}
struct InnerIndexReader {
num_searchers: usize,
searcher_pool: Pool<Searcher>,
index: Index,
}
impl InnerIndexReader {
fn reload(&self) -> Result<()> {
let segment_readers: Vec<SegmentReader> = {
let _meta_lock = self.index.directory().acquire_lock(&META_LOCK)?;
let searchable_segments = self.searchable_segments()?;
searchable_segments
.iter()
.map(SegmentReader::open)
.collect::<Result<_>>()?
};
let schema = self.index.schema();
let searchers = (0..self.num_searchers)
.map(|_| Searcher::new(schema.clone(), self.index.clone(), segment_readers.clone()))
.collect();
self.searcher_pool.publish_new_generation(searchers);
Ok(())
}
fn searchable_segments(&self) -> Result<Vec<Segment>> {
self.index.searchable_segments()
}
fn searcher(&self) -> LeasedItem<Searcher> {
self.searcher_pool.acquire()
}
}
#[derive(Clone)]
pub struct IndexReader {
inner: Arc<InnerIndexReader>,
watch_handle_opt: Option<WatchHandle>,
}
impl IndexReader {
pub fn reload(&self) -> Result<()> {
self.inner.reload()
}
pub fn searcher(&self) -> LeasedItem<Searcher> {
self.inner.searcher()
}
}