From 63c367b4877c345c05892b288b4cb4e5d5c5c9cf Mon Sep 17 00:00:00 2001
From: Lukas Wirth <lukastw97@gmail.com>
Date: Sat, 4 Jan 2025 10:37:36 +0100
Subject: [PATCH] Improve safety comments on function/fetch

---
 src/function/fetch.rs         | 14 ++++++--------
 src/function/input_outputs.rs | 21 ---------------------
 src/table.rs                  |  2 +-
 3 files changed, 7 insertions(+), 30 deletions(-)
 delete mode 100644 src/function/input_outputs.rs

diff --git a/src/function/fetch.rs b/src/function/fetch.rs
index f6d495df..65aeaea6 100644
--- a/src/function/fetch.rs
+++ b/src/function/fetch.rs
@@ -52,10 +52,9 @@ where
             if memo.value.is_some()
                 && self.shallow_verify_memo(db, zalsa, self.database_key_index(id), memo)
             {
-                // Unsafety invariant: memo is present in memo_map
-                unsafe {
-                    return Some(self.extend_memo_lifetime(memo));
-                }
+                // Unsafety invariant: memo is present in memo_map and we have verified that it is
+                // still valid for the current revision.
+                return unsafe { Some(self.extend_memo_lifetime(memo)) };
             }
         }
         None
@@ -81,10 +80,9 @@ where
         let opt_old_memo = self.get_memo_from_table_for(zalsa, id);
         if let Some(old_memo) = &opt_old_memo {
             if old_memo.value.is_some() && self.deep_verify_memo(db, old_memo, &active_query) {
-                // Unsafety invariant: memo is present in memo_map.
-                unsafe {
-                    return Some(self.extend_memo_lifetime(old_memo));
-                }
+                // Unsafety invariant: memo is present in memo_map and we have verified that it is
+                // still valid for the current revision.
+                return unsafe { Some(self.extend_memo_lifetime(old_memo)) };
             }
         }
 
diff --git a/src/function/input_outputs.rs b/src/function/input_outputs.rs
deleted file mode 100644
index dab66fdf..00000000
--- a/src/function/input_outputs.rs
+++ /dev/null
@@ -1,21 +0,0 @@
-use crate::{
-    accumulator::accumulated_map::AccumulatedMap, zalsa::Zalsa, zalsa_local::QueryOrigin, Id,
-};
-
-use super::{Configuration, IngredientImpl};
-
-impl<C> IngredientImpl<C>
-where
-    C: Configuration,
-{
-    pub(super) fn origin(&self, zalsa: &Zalsa, key: Id) -> Option<QueryOrigin> {
-        self.get_memo_from_table_for(zalsa, key)
-            .map(|m| m.revisions.origin.clone())
-    }
-
-    pub(super) fn accumulated(&self, zalsa: &Zalsa, key: Id) -> Option<&AccumulatedMap> {
-        // NEXT STEP: stash and refactor `fetch` to return an `&Memo` so we can make this work
-        self.get_memo_from_table_for(zalsa, key)
-            .map(|m| &m.revisions.accumulated)
-    }
-}
diff --git a/src/table.rs b/src/table.rs
index af6ace70..47296c7b 100644
--- a/src/table.rs
+++ b/src/table.rs
@@ -293,7 +293,7 @@ impl dyn TablePage {
 fn make_id(page: PageIndex, slot: SlotIndex) -> Id {
     let page = page.0 as u32;
     let slot = slot.0 as u32;
-    Id::from_u32(page << PAGE_LEN_BITS | slot)
+    Id::from_u32((page << PAGE_LEN_BITS) | slot)
 }
 
 fn split_id(id: Id) -> (PageIndex, SlotIndex) {