furnish batch interface with trait

Signed-off-by: Jason Volk <jason@zemos.net>

src/database/map/qry.rs

@@ -0,0 +1,54 @@
+use std::{convert::AsRef, fmt::Debug, io::Write, sync::Arc};
+
+use arrayvec::ArrayVec;
+use conduwuit::{implement, Result};
+use futures::Future;
+use serde::Serialize;
+
+use crate::{keyval::KeyBuf, ser, Handle};
+
+/// Fetch a value from the database into cache, returning a reference-handle
+/// asynchronously. The key is serialized into an allocated buffer to perform
+/// the query.
+#[implement(super::Map)]
+#[inline]
+pub fn qry<K>(self: &Arc<Self>, key: &K) -> impl Future<Output = Result<Handle<'_>>> + Send
+where
+	K: Serialize + ?Sized + Debug,
+{
+	let mut buf = KeyBuf::new();
+	self.bqry(key, &mut buf)
+}
+
+/// Fetch a value from the database into cache, returning a reference-handle
+/// asynchronously. The key is serialized into a fixed-sized buffer to perform
+/// the query. The maximum size is supplied as const generic parameter.
+#[implement(super::Map)]
+#[inline]
+pub fn aqry<const MAX: usize, K>(
+	self: &Arc<Self>,
+	key: &K,
+) -> impl Future<Output = Result<Handle<'_>>> + Send
+where
+	K: Serialize + ?Sized + Debug,
+{
+	let mut buf = ArrayVec::<u8, MAX>::new();
+	self.bqry(key, &mut buf)
+}
+
+/// Fetch a value from the database into cache, returning a reference-handle
+/// asynchronously. The key is serialized into a user-supplied Writer.
+#[implement(super::Map)]
+#[tracing::instrument(skip(self, buf), level = "trace")]
+pub fn bqry<K, B>(
+	self: &Arc<Self>,
+	key: &K,
+	buf: &mut B,
+) -> impl Future<Output = Result<Handle<'_>>> + Send
+where
+	K: Serialize + ?Sized + Debug,
+	B: Write + AsRef<[u8]>,
+{
+	let key = ser::serialize(buf, key).expect("failed to serialize query key");
+	self.get(key)
+}