1 files changed, 68 insertions, 0 deletions
diff --git a/src/model/block_ref_table.rs b/src/model/block_ref_table.rs
new file mode 100644
index 00000000..a00438c0
--- /dev/null
+++ b/src/model/block_ref_table.rs
@@ -0,0 +1,68 @@
+use async_trait::async_trait;
+use serde::{Deserialize, Serialize};
+use std::sync::Arc;
+
+use garage_util::background::*;
+use garage_util::data::*;
+use garage_util::error::Error;
+
+use garage_table::*;
+
+use crate::block::*;
+
+#[derive(PartialEq, Clone, Debug, Serialize, Deserialize)]
+pub struct BlockRef {
+	// Primary key
+	pub block: Hash,
+
+	// Sort key
+	pub version: UUID,
+
+	// Keep track of deleted status
+	pub deleted: bool,
+}
+
+impl Entry<Hash, UUID> for BlockRef {
+	fn partition_key(&self) -> &Hash {
+		&self.block
+	}
+	fn sort_key(&self) -> &UUID {
+		&self.version
+	}
+
+	fn merge(&mut self, other: &Self) {
+		if other.deleted {
+			self.deleted = true;
+		}
+	}
+}
+
+pub struct BlockRefTable {
+	pub background: Arc<BackgroundRunner>,
+	pub block_manager: Arc<BlockManager>,
+}
+
+#[async_trait]
+impl TableSchema for BlockRefTable {
+	type P = Hash;
+	type S = UUID;
+	type E = BlockRef;
+	type Filter = ();
+
+	async fn updated(&self, old: Option<Self::E>, new: Option<Self::E>) -> Result<(), Error> {
+		let block = &old.as_ref().or(new.as_ref()).unwrap().block;
+		let was_before = old.as_ref().map(|x| !x.deleted).unwrap_or(false);
+		let is_after = new.as_ref().map(|x| !x.deleted).unwrap_or(false);
+		if is_after && !was_before {
+			self.block_manager.block_incref(block)?;
+		}
+		if was_before && !is_after {
+			self.block_manager.block_decref(block)?;
+		}
+		Ok(())
+	}
+
+	fn matches_filter(entry: &Self::E, _filter: &Self::Filter) -> bool {
+		!entry.deleted
+	}
+}