implement poll

src/storage/garage.rs

@@ -191,7 +191,36 @@ impl IStore for GarageStore {
         }
     }
     async fn row_poll(&self, value: &RowRef) -> Result<RowVal, StorageError> {
-        unimplemented!();
+        loop {
+            if let Some(ct) = &value.causality {
+                match self.k2v.poll_item(&value.uid.shard, &value.uid.sort, ct.clone().into(), None).await {
+                    Err(e) => {
+                        tracing::error!("Unable to poll item: {}", e);
+                        return Err(StorageError::Internal);
+                    }
+                    Ok(None) => continue,
+                    Ok(Some(cv)) => return Ok(causal_to_row_val(value.clone(), cv)),
+                }
+            } else {
+                match self.k2v.read_item(&value.uid.shard, &value.uid.sort).await {
+                    Err(k2v_client::Error::NotFound) => {
+                        self
+                            .k2v
+                            .insert_item(&value.uid.shard, &value.uid.sort, vec![0u8], None)
+                            .await
+                            .map_err(|e| {
+                                tracing::error!("Unable to insert item in polling logic: {}", e);
+                                StorageError::Internal
+                            })?;
+                    }
+                    Err(e) => {
+                        tracing::error!("Unable to read item in polling logic: {}", e);
+                        return Err(StorageError::Internal)
+                    },
+                    Ok(cv) => return Ok(causal_to_row_val(value.clone(), cv)),
+                }
+            }
+        }
     }
 
     async fn row_rm_single(&self, entry: &RowRef) -> Result<(), StorageError> {