Redesign transfer trait

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "skl"
-version = "0.22.15"
+version = "0.22.16"
 edition = "2021"
 rust-version = "1.81.0"
 repository = "https://github.com/al8n/skl"

src/dynamic/list.rs

@@ -15,7 +15,7 @@ use crate::{
   ref_counter::RefCounter,
   traits::Constructable,
   types::{internal::ValuePointer as ValuePointerType, Height, KeyBuilder, ValueBuilder},
-  FindResult, Header, Inserter, MaybeTombstone, Splice, State, Transformable, Version,
+  FindResult, Header, Inserter, MaybeTombstone, Splice, Transfer, Version,
 };
 
 mod entry;
@@ -318,8 +318,7 @@ where
     contains_key: impl Fn(&[u8]) -> bool,
   ) -> Option<EntryRef<'a, S, C, A, R>>
   where
-    S: State,
-    S::Data<'a, &'a [u8]>: Transformable<Input = Option<&'a [u8]>>,
+    S: Transfer<'a, &'a [u8]>,
   {
     loop {
       unsafe {
@@ -337,13 +336,8 @@ where
           let pointer = nd.get_value_pointer::<A>();
           let value =
             nd.get_value_by_value_offset(&self.arena, pointer.value_offset, pointer.value_len);
-          let ent = EntryRef::from_node_with_pointer(
-            version,
-            *nd,
-            self,
-            Some(nk),
-            <S::Data<'a, &'a [u8]> as Transformable>::from_input(value),
-          );
+          let ent =
+            EntryRef::from_node_with_pointer(version, *nd, self, Some(nk), S::from_input(value));
           return Some(ent);
         }
 
@@ -359,8 +353,7 @@ where
     contains_key: impl Fn(&[u8]) -> bool,
   ) -> Option<EntryRef<'a, S, C, A, R>>
   where
-    S: State,
-    S::Data<'a, &'a [u8]>: Transformable<Input = Option<&'a [u8]>>,
+    S: Transfer<'a, &'a [u8]>,
   {
     loop {
       unsafe {
@@ -390,7 +383,7 @@ where
                 *nd,
                 self,
                 Some(nk),
-                <S::Data<'a, &'a [u8]> as Transformable>::from_input(value),
+                S::from_input(value),
               );
               return Some(ent);
             }
@@ -411,13 +404,8 @@ where
           let pointer = nd.get_value_pointer::<A>();
           let value =
             nd.get_value_by_value_offset(&self.arena, pointer.value_offset, pointer.value_len);
-          let ent = EntryRef::from_node_with_pointer(
-            version,
-            *nd,
-            self,
-            Some(nk),
-            <S::Data<'a, &'a [u8]> as Transformable>::from_input(value),
-          );
+          let ent =
+            EntryRef::from_node_with_pointer(version, *nd, self, Some(nk), S::from_input(value));
           return Some(ent);
         }
 
@@ -433,8 +421,7 @@ where
     contains_key: impl Fn(&[u8]) -> bool,
   ) -> Option<EntryRef<'a, S, C, A, R>>
   where
-    S: State,
-    S::Data<'a, &'a [u8]>: Transformable<Input = Option<&'a [u8]>>,
+    S: Transfer<'a, &'a [u8]>,
   {
     loop {
       unsafe {
@@ -452,13 +439,8 @@ where
           let pointer = nd.get_value_pointer::<A>();
           let value =
             nd.get_value_by_value_offset(&self.arena, pointer.value_offset, pointer.value_len);
-          let ent = EntryRef::from_node_with_pointer(
-            version,
-            *nd,
-            self,
-            Some(nk),
-            <S::Data<'a, &'a [u8]> as Transformable>::from_input(value),
-          );
+          let ent =
+            EntryRef::from_node_with_pointer(version, *nd, self, Some(nk), S::from_input(value));
           return Some(ent);
         }
 
@@ -474,8 +456,7 @@ where
     contains_key: impl Fn(&[u8]) -> bool,
   ) -> Option<EntryRef<'a, S, C, A, R>>
   where
-    S: State,
-    S::Data<'a, &'a [u8]>: Sized + Transformable<Input = Option<&'a [u8]>>,
+    S: Transfer<'a, &'a [u8]>,
   {
     loop {
       unsafe {
@@ -522,7 +503,7 @@ where
             *nd,
             self,
             Some(nk),
-            <S::Data<'a, &'a [u8]> as Transformable>::from_input(value),
+            <S as crate::sealed::Sealed<'_, &[u8]>>::from_input(value),
           );
           return Some(ent);
         }

src/dynamic/list/entry.rs

@@ -2,7 +2,7 @@ use crate::{
   allocator::{Allocator, Node, NodePointer, WithVersion},
   dynamic::list::SkipList,
   ref_counter::RefCounter,
-  Active, MaybeTombstone, State, Transformable, Version,
+  Active, MaybeTombstone, State, Transfer, Version,
 };
 use dbutils::equivalentor::BytesComparator;
 
@@ -104,18 +104,18 @@ where
 
   /// Returns the reference to the value, `None` means the entry is removed.
   #[inline]
-  pub fn value(&self) -> <S::Data<'a, &'a [u8]> as Transformable>::Output
+  pub fn value(&self) -> S::Data<'a, S::To>
   where
-    S::Data<'a, &'a [u8]>: Transformable,
+    S: Transfer<'a, &'a [u8]>,
   {
-    self.value.transform()
+    S::transfer(&self.value)
   }
 
   /// Returns `true` if the entry is marked as removed
   #[inline]
   pub fn tombstone(&self) -> bool
   where
-    S::Data<'a, &'a [u8]>: Transformable,
+    S: Transfer<'a, &'a [u8]>,
   {
     !S::validate_data(&self.value)
   }
@@ -126,8 +126,7 @@ where
   C: BytesComparator,
   A: Allocator,
   R: RefCounter,
-  S: State,
-  S::Data<'a, &'a [u8]>: Sized + Transformable<Input = Option<&'a [u8]>>,
+  S: Transfer<'a, &'a [u8]>,
 {
   /// Returns the next entry in the map.
   #[inline]

src/dynamic/list/iterator.rs

@@ -1,5 +1,5 @@
 use super::{Allocator, EntryRef, NodePointer, RefCounter, SkipList, Version};
-use crate::{allocator::Node, State, Transformable};
+use crate::{allocator::Node, State, Transfer};
 use core::{
   borrow::Borrow,
   ops::{Bound, RangeBounds},
@@ -155,8 +155,8 @@ where
   RC: RefCounter,
   Q: ?Sized + Borrow<[u8]>,
   R: RangeBounds<Q>,
-  S: State,
-  S::Data<'a, &'a [u8]>: Copy + Transformable<Input = Option<&'a [u8]>>,
+  S: Transfer<'a, &'a [u8]>,
+  S::Data<'a, &'a [u8]>: Copy,
 {
   /// Advances to the next position. Returns the key and value if the
   /// iterator is pointing at a valid entry, and `None` otherwise.
@@ -384,8 +384,8 @@ where
   RC: RefCounter,
   Q: ?Sized + Borrow<[u8]>,
   R: RangeBounds<Q>,
-  S: State,
-  S::Data<'a, &'a [u8]>: Copy + Transformable<Input = Option<&'a [u8]>>,
+  S: Transfer<'a, &'a [u8]>,
+  S::Data<'a, &'a [u8]>: Copy,
 {
   /// Moves the iterator to the highest element whose key is below the given bound.
   /// If no such element is found then `None` is returned.
@@ -604,8 +604,8 @@ where
   RC: RefCounter,
   Q: ?Sized + Borrow<[u8]>,
   R: RangeBounds<Q>,
-  S: State,
-  S::Data<'a, &'a [u8]>: Copy + Transformable<Input = Option<&'a [u8]>>,
+  S: Transfer<'a, &'a [u8]>,
+  S::Data<'a, &'a [u8]>: Copy,
 {
   type Item = EntryRef<'a, S, C, A, RC>;
 
@@ -652,8 +652,8 @@ where
   RC: RefCounter,
   Q: ?Sized + Borrow<[u8]>,
   R: RangeBounds<Q>,
-  S: State,
-  S::Data<'a, &'a [u8]>: Copy + Transformable<Input = Option<&'a [u8]>>,
+  S: Transfer<'a, &'a [u8]>,
+  S::Data<'a, &'a [u8]>: Copy,
 {
   #[inline]
   fn next_back(&mut self) -> Option<Self::Item> {

src/generic/list.rs

@@ -13,15 +13,15 @@ use crate::{
   allocator::{Allocator, Deallocator, Meta, Node, NodePointer, Pointer, ValuePointer},
   encode_key_size_and_height,
   error::Error,
-  generic::{MaybeTombstone, State},
+  generic::MaybeTombstone,
   internal::RefMeta,
   options::CompressionPolicy,
   random_height,
   ref_counter::RefCounter,
   traits::Constructable,
   ty_ref,
   types::{internal::ValuePointer as ValuePointerType, Height, KeyBuilder, ValueBuilder},
-  FindResult, Header, Inserter, Splice, Transformable, Version,
+  FindResult, Header, Inserter, Splice, Transfer, Version,
 };
 
 mod entry;
@@ -357,8 +357,7 @@ where
     contains_key: impl Fn(&K::Ref<'a>) -> bool,
   ) -> Option<EntryRef<'a, K, V, S, C, A, R>>
   where
-    S: State,
-    S::Data<'a, LazyRef<'a, V>>: Transformable<Input = Option<&'a [u8]>>,
+    S: Transfer<'a, LazyRef<'a, V>>,
   {
     loop {
       unsafe {
@@ -392,8 +391,7 @@ where
     contains_key: impl Fn(&K::Ref<'a>) -> bool,
   ) -> Option<EntryRef<'a, K, V, S, C, A, R>>
   where
-    S: State,
-    S::Data<'a, LazyRef<'a, V>>: Transformable<Input = Option<&'a [u8]>>,
+    S: Transfer<'a, LazyRef<'a, V>>,
     C: TypeRefEquivalentor<'a, K>,
   {
     loop {
@@ -461,8 +459,7 @@ where
     contains_key: impl Fn(&K::Ref<'a>) -> bool,
   ) -> Option<EntryRef<'a, K, V, S, C, A, R>>
   where
-    S: State,
-    S::Data<'a, LazyRef<'a, V>>: Transformable<Input = Option<&'a [u8]>>,
+    S: Transfer<'a, LazyRef<'a, V>>,
   {
     loop {
       unsafe {
@@ -497,8 +494,7 @@ where
     contains_key: impl Fn(&K::Ref<'a>) -> bool,
   ) -> Option<EntryRef<'a, K, V, S, C, A, R>>
   where
-    S: State,
-    S::Data<'a, LazyRef<'a, V>>: Transformable<Input = Option<&'a [u8]>>,
+    S: Transfer<'a, LazyRef<'a, V>>,
     C: TypeRefEquivalentor<'a, K>,
   {
     loop {

src/generic/list/entry.rs

@@ -8,7 +8,7 @@ use crate::{
   allocator::{Allocator, Node, NodePointer, WithVersion},
   generic::{Active, MaybeTombstone, State},
   types::internal::ValuePointer,
-  Transformable, Version,
+  Transfer, Version,
 };
 
 /// An entry reference of the `SkipMap`.
@@ -35,9 +35,8 @@ where
   V: ?Sized + Type,
   A: Allocator,
   R: RefCounter,
-  S: State,
-  S::Data<'a, LazyRef<'a, V>>: Transformable,
-  <S::Data<'a, LazyRef<'a, V>> as Transformable>::Output: core::fmt::Debug,
+  S: Transfer<'a, LazyRef<'a, V>>,
+  S::Data<'a, S::To>: core::fmt::Debug,
 {
   fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
     f.debug_struct("EntryRef")
@@ -119,27 +118,27 @@ where
 
   /// Returns the reference to the value, `None` means the entry is removed.
   #[inline]
-  pub fn value(&self) -> <S::Data<'a, LazyRef<'a, V>> as Transformable>::Output
+  pub fn value(&self) -> S::Data<'a, S::To>
   where
-    S::Data<'a, LazyRef<'a, V>>: Transformable,
+    S: Transfer<'a, LazyRef<'a, V>>,
   {
-    self.value.transform()
+    S::transfer(&self.value)
   }
 
   /// Returns the value in raw bytes
   #[inline]
-  pub fn raw_value(&self) -> <S::Data<'a, LazyRef<'a, V>> as Transformable>::Input
+  pub fn raw_value(&self) -> S::Data<'a, &'a [u8]>
   where
-    S::Data<'a, LazyRef<'a, V>>: Transformable,
+    S: Transfer<'a, LazyRef<'a, V>>,
   {
-    self.value.input()
+    S::input(&self.value)
   }
 
   /// Returns `true` if the entry is marked as removed
   #[inline]
   pub fn tombstone(&self) -> bool
   where
-    S::Data<'a, LazyRef<'a, V>>: Transformable,
+    S: Transfer<'a, LazyRef<'a, V>>,
   {
     !S::validate_data(&self.value)
   }
@@ -149,8 +148,7 @@ impl<'a, K, V, S, C, A, R> EntryRef<'a, K, V, S, C, A, R>
 where
   K: ?Sized + Type,
   V: ?Sized + Type,
-  S: State,
-  S::Data<'a, LazyRef<'a, V>>: Sized + Transformable<Input = Option<&'a [u8]>>,
+  S: Transfer<'a, LazyRef<'a, V>>,
   A: Allocator,
   R: RefCounter,
   C: TypeRefComparator<'a, K>,
@@ -226,8 +224,7 @@ impl<'a, K, V, S, C, A, R> EntryRef<'a, K, V, S, C, A, R>
 where
   K: ?Sized + Type,
   V: ?Sized + Type,
-  S: State,
-  S::Data<'a, LazyRef<'a, V>>: Transformable<Input = Option<&'a [u8]>>,
+  S: Transfer<'a, LazyRef<'a, V>>,
   A: Allocator,
   R: RefCounter,
 {
@@ -258,7 +255,7 @@ where
       Self {
         list,
         key,
-        value: <S::Data<'a, LazyRef<'a, V>> as Transformable>::from_input(raw_value),
+        value: S::from_input(raw_value),
         value_part_pointer: vp,
         version: node.version(),
         query_version,
@@ -297,7 +294,7 @@ where
       Self {
         list,
         key,
-        value: <S::Data<'a, LazyRef<'a, V>> as Transformable>::from_input(raw_value),
+        value: S::from_input(raw_value),
         value_part_pointer: pointer,
         version: node.version(),
         query_version,