conduwuit/src/database/map/stream_prefix.rs
Jason Volk 98e6c81e49 offload remaining db iterator initial seeks on cache miss
consume task budget on cache hit

Signed-off-by: Jason Volk <jason@zemos.net>
2025-01-01 23:28:01 -05:00

77 lines
2.1 KiB
Rust

use std::{convert::AsRef, fmt::Debug, sync::Arc};
use conduwuit::{implement, Result};
use futures::{future, Stream, StreamExt, TryStreamExt};
use serde::{Deserialize, Serialize};
use crate::keyval::{result_deserialize, serialize_key, KeyVal};
/// Iterate key-value entries in the map where the key matches a prefix.
///
/// - Query is serialized
/// - Result is deserialized
#[implement(super::Map)]
pub fn stream_prefix<'a, K, V, P>(
self: &'a Arc<Self>,
prefix: &P,
) -> impl Stream<Item = Result<KeyVal<'_, K, V>>> + Send
where
P: Serialize + ?Sized + Debug,
K: Deserialize<'a> + Send,
V: Deserialize<'a> + Send,
{
self.stream_prefix_raw(prefix)
.map(result_deserialize::<K, V>)
}
/// Iterate key-value entries in the map where the key matches a prefix.
///
/// - Query is serialized
/// - Result is raw
#[implement(super::Map)]
#[tracing::instrument(skip(self), level = "trace")]
pub fn stream_prefix_raw<P>(
self: &Arc<Self>,
prefix: &P,
) -> impl Stream<Item = Result<KeyVal<'_>>> + Send
where
P: Serialize + ?Sized + Debug,
{
let key = serialize_key(prefix).expect("failed to serialize query key");
self.raw_stream_from(&key)
.try_take_while(move |(k, _): &KeyVal<'_>| future::ok(k.starts_with(&key)))
}
/// Iterate key-value entries in the map where the key matches a prefix.
///
/// - Query is raw
/// - Result is deserialized
#[implement(super::Map)]
pub fn stream_raw_prefix<'a, K, V, P>(
self: &'a Arc<Self>,
prefix: &'a P,
) -> impl Stream<Item = Result<KeyVal<'_, K, V>>> + Send + 'a
where
P: AsRef<[u8]> + ?Sized + Debug + Sync + 'a,
K: Deserialize<'a> + Send + 'a,
V: Deserialize<'a> + Send + 'a,
{
self.raw_stream_prefix(prefix)
.map(result_deserialize::<K, V>)
}
/// Iterate key-value entries in the map where the key matches a prefix.
///
/// - Query is raw
/// - Result is raw
#[implement(super::Map)]
pub fn raw_stream_prefix<'a, P>(
self: &'a Arc<Self>,
prefix: &'a P,
) -> impl Stream<Item = Result<KeyVal<'_>>> + Send + 'a
where
P: AsRef<[u8]> + ?Sized + Debug + Sync + 'a,
{
self.raw_stream_from(prefix)
.try_take_while(|(k, _): &KeyVal<'_>| future::ok(k.starts_with(prefix.as_ref())))
}