small cleanup

src/allocator.rs

@@ -569,7 +569,7 @@ impl SlabPointer {
     pub fn allocate_page(&self, db: &mut Db) -> FilePointer {
         let Slab { head, size } = self.read(db);
 
-        println!("allocate_page({size})");
+        println!("allocate_slab_page({size})");
 
         let size = size.get();
 

src/lib.rs

@@ -1,3 +1,4 @@
+#![allow(unused)]
 use std::{
     collections::{BTreeMap, VecDeque},
     fmt::Debug,
@@ -14,7 +15,6 @@ mod transaction;
 
 use allocator::{AllocatorState, GeneralPurposeAllocator, SlabListPointer, SlabPointer};
 use atomic_arc::AtomicArc;
-use mapped::ReaderTrait;
 use memmap::{Mmap, MmapMut};
 use transaction::TransactionHandle;
 use zerocopy::{AsBytes, FromBytes, LayoutVerified, Unaligned, LE};
@@ -236,7 +236,7 @@ impl Db {
         {
             // if the snapshot is uniqe we are the only owner and can free the epoch.
 
-            println!("freeing epoch");
+            // println!("freeing epoch");
 
             let snapshot = snapshots.pop_front().unwrap();
 
@@ -487,10 +487,11 @@ impl Db {
 
 #[cfg(test)]
 mod tests {
+    use super::*;
+    use mapped::ReaderTrait;
     use std::io::Write;
     use std::process::Stdio;
 
-    use super::*;
     #[derive(Debug, Clone, Copy)]
     enum Operation {
         Allocate { size: u64 },
@@ -719,14 +720,31 @@ mod tests {
 
                 assert_eq!(data.generation.get(), i);
 
+                let n = {
+                    let mut next = data.list;
+                    let mut n = 0;
+                    while !next.is_null() {
+                        next = transaction.read::<DataList>(next).next;
+                        n += 1;
+                    }
+                    n
+                };
+
+                let next = if n >= 5 {
+                    transaction.read::<DataList>(data.list).next
+                } else {
+                    data.list
+                };
+
                 let (elem_ptr, element) = transaction.allocate::<DataList>();
 
-                element.next = data.list;
+                element.next = next;
                 element.data = i.into();
 
                 let (root, data) = transaction.modify::<DataHeader>(root);
                 data.list = elem_ptr.start;
                 data.generation = (i + 1).into();
+
                 root.start
             });
 
@@ -749,8 +767,10 @@ mod tests {
                 ptr = element.next;
             }
 
-            assert_eq!(items.len(), i + 1);
-            for (expected, &is) in items.iter().rev().enumerate() {
+            assert_eq!(items.len(), (i + 1).min(5));
+            assert_eq!(items[0], i as u64);
+
+            for (expected, &is) in items.iter().skip(1).rev().enumerate() {
                 assert_eq!(expected as u64, is);
             }
         }

src/transaction.rs

@@ -132,7 +132,11 @@ impl<'t> TransactionHandle<'t> {
         }
     }
 
-    pub fn free(&mut self, range: FileRange) {
+    pub fn free<T>(&mut self, at: FilePointer) {
+        self.free_range(at.range(size_of::<T>() as u64))
+    }
+
+    pub fn free_range(&mut self, range: FileRange) {
         let mut freed = false;
 
         if let Some(allocation) = self.new.remove(&range.start) {
@@ -141,7 +145,7 @@ impl<'t> TransactionHandle<'t> {
             freed = true;
         }
 
-        for (_, replaced) in &mut self.replaced {
+        for replaced in self.replaced.values_mut() {
             if replaced.from == range || replaced.to == Some(range) {
                 replaced.to = None;
                 freed = true;