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-rw-r--r--src/table/schema.rs77
1 files changed, 77 insertions, 0 deletions
diff --git a/src/table/schema.rs b/src/table/schema.rs
new file mode 100644
index 00000000..cedaacac
--- /dev/null
+++ b/src/table/schema.rs
@@ -0,0 +1,77 @@
+use async_trait::async_trait;
+use serde::{Deserialize, Serialize};
+
+use garage_util::data::*;
+use garage_util::error::Error;
+
+
+pub trait PartitionKey {
+ fn hash(&self) -> Hash;
+}
+
+pub trait SortKey {
+ fn sort_key(&self) -> &[u8];
+}
+
+pub trait Entry<P: PartitionKey, S: SortKey>:
+ PartialEq + Clone + Serialize + for<'de> Deserialize<'de> + Send + Sync
+{
+ fn partition_key(&self) -> &P;
+ fn sort_key(&self) -> &S;
+
+ fn merge(&mut self, other: &Self);
+}
+
+#[derive(Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct EmptyKey;
+impl SortKey for EmptyKey {
+ fn sort_key(&self) -> &[u8] {
+ &[]
+ }
+}
+impl PartitionKey for EmptyKey {
+ fn hash(&self) -> Hash {
+ [0u8; 32].into()
+ }
+}
+
+impl PartitionKey for String {
+ fn hash(&self) -> Hash {
+ hash(self.as_bytes())
+ }
+}
+impl SortKey for String {
+ fn sort_key(&self) -> &[u8] {
+ self.as_bytes()
+ }
+}
+
+impl PartitionKey for Hash {
+ fn hash(&self) -> Hash {
+ self.clone()
+ }
+}
+impl SortKey for Hash {
+ fn sort_key(&self) -> &[u8] {
+ self.as_slice()
+ }
+}
+
+#[async_trait]
+pub trait TableSchema: Send + Sync {
+ type P: PartitionKey + Clone + PartialEq + Serialize + for<'de> Deserialize<'de> + Send + Sync;
+ type S: SortKey + Clone + Serialize + for<'de> Deserialize<'de> + Send + Sync;
+ type E: Entry<Self::P, Self::S>;
+ type Filter: Clone + Serialize + for<'de> Deserialize<'de> + Send + Sync;
+
+ // Action to take if not able to decode current version:
+ // try loading from an older version
+ fn try_migrate(_bytes: &[u8]) -> Option<Self::E> {
+ None
+ }
+
+ async fn updated(&self, old: Option<Self::E>, new: Option<Self::E>) -> Result<(), Error>;
+ fn matches_filter(_entry: &Self::E, _filter: &Self::Filter) -> bool {
+ true
+ }
+}