consolidate key/value types; consistent interface arguments

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

src/database/map.rs

@@ -1,11 +1,16 @@
-use std::{future::Future, pin::Pin, sync::Arc};
+use std::{future::Future, mem::size_of, pin::Pin, sync::Arc};
 
 use conduit::{utils, Result};
 use rocksdb::{
 	AsColumnFamilyRef, ColumnFamily, Direction, IteratorMode, ReadOptions, WriteBatchWithTransaction, WriteOptions,
 };
 
-use crate::{or_else, result, watchers::Watchers, Engine, Handle, Iter};
+use crate::{
+	or_else, result,
+	slice::{Byte, Key, KeyVal, OwnedKey, OwnedKeyValPair, OwnedVal, Val},
+	watchers::Watchers,
+	Engine, Handle, Iter,
+};
 
 pub struct Map {
 	name: String,
@@ -16,9 +21,7 @@ pub struct Map {
 	read_options: ReadOptions,
 }
 
-pub(crate) type KeyVal = (Key, Val);
-pub(crate) type Val = Vec<u8>;
-pub(crate) type Key = Vec<u8>;
+type OwnedKeyValPairIter<'a> = Box<dyn Iterator<Item = OwnedKeyValPair> + Send + 'a>;
 
 impl Map {
 	pub(crate) fn open(db: &Arc<Engine>, name: &str) -> Result<Arc<Self>> {
@@ -32,19 +35,19 @@ impl Map {
 		}))
 	}
 
-	pub fn get(&self, key: &[u8]) -> Result<Option<Handle<'_>>> {
+	pub fn get(&self, key: &Key) -> Result<Option<Handle<'_>>> {
 		let read_options = &self.read_options;
 		let res = self.db.db.get_pinned_cf_opt(&self.cf(), key, read_options);
 
 		Ok(result(res)?.map(Handle::from))
 	}
 
-	pub fn multi_get(&self, keys: &[&[u8]]) -> Result<Vec<Option<Vec<u8>>>> {
+	pub fn multi_get(&self, keys: &[&Key]) -> Result<Vec<Option<OwnedVal>>> {
 		// Optimization can be `true` if key vector is pre-sorted **by the column
 		// comparator**.
 		const SORTED: bool = false;
 
-		let mut ret: Vec<Option<Vec<u8>>> = Vec::with_capacity(keys.len());
+		let mut ret: Vec<Option<OwnedKey>> = Vec::with_capacity(keys.len());
 		let read_options = &self.read_options;
 		for res in self
 			.db
@@ -61,7 +64,7 @@ impl Map {
 		Ok(ret)
 	}
 
-	pub fn insert(&self, key: &[u8], value: &[u8]) -> Result<()> {
+	pub fn insert(&self, key: &Key, value: &Val) -> Result<()> {
 		let write_options = &self.write_options;
 		self.db
 			.db
@@ -77,9 +80,12 @@ impl Map {
 		Ok(())
 	}
 
-	pub fn insert_batch(&self, iter: &mut dyn Iterator<Item = KeyVal>) -> Result<()> {
+	pub fn insert_batch<'a, I>(&'a self, iter: I) -> Result<()>
+	where
+		I: Iterator<Item = KeyVal<'a>>,
+	{
 		let mut batch = WriteBatchWithTransaction::<false>::default();
-		for (key, value) in iter {
+		for KeyVal(key, value) in iter {
 			batch.put_cf(&self.cf(), key, value);
 		}
 
@@ -93,7 +99,7 @@ impl Map {
 		result(res)
 	}
 
-	pub fn remove(&self, key: &[u8]) -> Result<()> {
+	pub fn remove(&self, key: &Key) -> Result<()> {
 		let write_options = &self.write_options;
 		let res = self.db.db.delete_cf_opt(&self.cf(), key, write_options);
 
@@ -104,7 +110,10 @@ impl Map {
 		result(res)
 	}
 
-	pub fn remove_batch(&self, iter: &mut dyn Iterator<Item = Key>) -> Result<()> {
+	pub fn remove_batch<'a, I>(&'a self, iter: I) -> Result<()>
+	where
+		I: Iterator<Item = &'a Key>,
+	{
 		let mut batch = WriteBatchWithTransaction::<false>::default();
 		for key in iter {
 			batch.delete_cf(&self.cf(), key);
@@ -120,14 +129,14 @@ impl Map {
 		result(res)
 	}
 
-	pub fn iter<'a>(&'a self) -> Box<dyn Iterator<Item = KeyVal> + 'a> {
+	pub fn iter(&self) -> OwnedKeyValPairIter<'_> {
 		let mode = IteratorMode::Start;
 		let read_options = read_options_default();
 		Box::new(Iter::new(&self.db, &self.cf, read_options, &mode))
 	}
 
-	pub fn iter_from<'a>(&'a self, from: &[u8], backwards: bool) -> Box<dyn Iterator<Item = KeyVal> + 'a> {
-		let direction = if backwards {
+	pub fn iter_from(&self, from: &Key, reverse: bool) -> OwnedKeyValPairIter<'_> {
+		let direction = if reverse {
 			Direction::Reverse
 		} else {
 			Direction::Forward
@@ -137,13 +146,13 @@ impl Map {
 		Box::new(Iter::new(&self.db, &self.cf, read_options, &mode))
 	}
 
-	pub fn scan_prefix<'a>(&'a self, prefix: Vec<u8>) -> Box<dyn Iterator<Item = KeyVal> + 'a> {
+	pub fn scan_prefix(&self, prefix: OwnedKey) -> OwnedKeyValPairIter<'_> {
 		let mode = IteratorMode::From(&prefix, Direction::Forward);
 		let read_options = read_options_default();
 		Box::new(Iter::new(&self.db, &self.cf, read_options, &mode).take_while(move |(k, _)| k.starts_with(&prefix)))
 	}
 
-	pub fn increment(&self, key: &[u8]) -> Result<[u8; 8]> {
+	pub fn increment(&self, key: &Key) -> Result<[Byte; size_of::<u64>()]> {
 		let old = self.get(key)?;
 		let new = utils::increment(old.as_deref());
 		self.insert(key, &new)?;
@@ -155,10 +164,13 @@ impl Map {
 		Ok(new)
 	}
 
-	pub fn increment_batch(&self, iter: &mut dyn Iterator<Item = Val>) -> Result<()> {
+	pub fn increment_batch<'a, I>(&'a self, iter: I) -> Result<()>
+	where
+		I: Iterator<Item = &'a Key>,
+	{
 		let mut batch = WriteBatchWithTransaction::<false>::default();
 		for key in iter {
-			let old = self.get(&key)?;
+			let old = self.get(key)?;
 			let new = utils::increment(old.as_deref());
 			batch.put_cf(&self.cf(), key, new);
 		}
@@ -173,7 +185,7 @@ impl Map {
 		result(res)
 	}
 
-	pub fn watch_prefix<'a>(&'a self, prefix: &[u8]) -> Pin<Box<dyn Future<Output = ()> + Send + 'a>> {
+	pub fn watch_prefix<'a>(&'a self, prefix: &Key) -> Pin<Box<dyn Future<Output = ()> + Send + 'a>> {
 		self.watchers.watch(prefix)
 	}
 
@@ -184,8 +196,8 @@ impl Map {
 }
 
 impl<'a> IntoIterator for &'a Map {
-	type IntoIter = Box<dyn Iterator<Item = Self::Item> + 'a>;
-	type Item = KeyVal;
+	type IntoIter = Box<dyn Iterator<Item = Self::Item> + Send + 'a>;
+	type Item = OwnedKeyValPair;
 
 	fn into_iter(self) -> Self::IntoIter { self.iter() }
 }