reorganize database crate.

split database Cork into unit.

split database migrations from mod.rs

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

src/database/kvtree.rs

@@ -0,0 +1,60 @@
+use std::{future::Future, pin::Pin, sync::Arc};
+
+use crate::Result;
+
+pub(crate) trait KvTree: Send + Sync {
+	fn get(&self, key: &[u8]) -> Result<Option<Vec<u8>>>;
+
+	#[allow(dead_code)]
+	#[cfg(feature = "rocksdb")]
+	fn multi_get(
+		&self, _iter: Vec<(&Arc<rust_rocksdb::BoundColumnFamily<'_>>, Vec<u8>)>,
+	) -> Vec<Result<Option<Vec<u8>>, rust_rocksdb::Error>> {
+		unimplemented!()
+	}
+
+	fn insert(&self, key: &[u8], value: &[u8]) -> Result<()>;
+	fn insert_batch(&self, iter: &mut dyn Iterator<Item = (Vec<u8>, Vec<u8>)>) -> Result<()> {
+		for (key, value) in iter {
+			self.insert(&key, &value)?;
+		}
+
+		Ok(())
+	}
+
+	fn remove(&self, key: &[u8]) -> Result<()>;
+
+	#[allow(dead_code)]
+	fn remove_batch(&self, iter: &mut dyn Iterator<Item = Vec<u8>>) -> Result<()> {
+		for key in iter {
+			self.remove(&key)?;
+		}
+
+		Ok(())
+	}
+
+	fn iter<'a>(&'a self) -> Box<dyn Iterator<Item = (Vec<u8>, Vec<u8>)> + 'a>;
+
+	fn iter_from<'a>(&'a self, from: &[u8], backwards: bool) -> Box<dyn Iterator<Item = (Vec<u8>, Vec<u8>)> + 'a>;
+
+	fn increment(&self, key: &[u8]) -> Result<Vec<u8>>;
+	fn increment_batch(&self, iter: &mut dyn Iterator<Item = Vec<u8>>) -> Result<()> {
+		for key in iter {
+			self.increment(&key)?;
+		}
+
+		Ok(())
+	}
+
+	fn scan_prefix<'a>(&'a self, prefix: Vec<u8>) -> Box<dyn Iterator<Item = (Vec<u8>, Vec<u8>)> + 'a>;
+
+	fn watch_prefix<'a>(&'a self, prefix: &[u8]) -> Pin<Box<dyn Future<Output = ()> + Send + 'a>>;
+
+	fn clear(&self) -> Result<()> {
+		for (key, _) in self.iter() {
+			self.remove(&key)?;
+		}
+
+		Ok(())
+	}
+}