database: return owned T in Storable (#92)

* add `storable_slice.rs`

* storable: `from_bytes(&[u8]) -> Self`

* heed: return `T` in `Storable`, use `StorableSlice` in tests

* remove `value_guard.rs`

* redb: update `Storable` to return owned `T`

* database: return `T` directly, remove `'a` lifetime

* replace `[]` with `StorableSlice`

* tables: add lifetime to `tables!()` and generated structs

* backend: fix tests

* heed: update fn signatures

* storable: add `StorableVec`, remove `Storable::ALIGN`

* tables/types: remove slice lifetimes, use `StorableVec`

* backend: use `StorableVec`, fix tests

* types: fix tests to use owned returned value

* heed: fix `Storable` impl and tests

* storable: `StorableVec` docs + tests

* backend: assert values are detached from `get_range()` iterator

* database: add docs

* udpate docs, remove unneeded clippy `allow`

* replace `ToOwnedDebug` with `std::fmt::Debug`

* impl `StorableBytes`

* backend: add `StorableBytes` to tests

* readme: remove `to_owned_debug.rs` reference

Cargo.lock

@@ -592,6 +592,7 @@ name = "cuprate-database"
 version = "0.0.0"
 dependencies = [
  "bytemuck",
+ "bytes",
  "cfg-if",
  "crossbeam",
  "cuprate-helper",

database/Cargo.toml

@@ -9,14 +9,15 @@ repository  = "https://github.com/Cuprate/cuprate/tree/main/database"
 keywords    = ["cuprate", "database"]
 
 [features]
-# default   = ["heed", "redb", "service"]
+default   = ["heed", "redb", "service"]
-default   = ["redb", "service"]
+# default   = ["redb", "service"]
 heed    = ["dep:heed"]
 redb    = ["dep:redb"]
 service = ["dep:crossbeam", "dep:futures", "dep:tokio", "dep:tokio-util", "dep:tower", "dep:rayon"]
 
 [dependencies]
 bytemuck = { version = "1.14.3", features = ["must_cast", "derive", "min_const_generics", "extern_crate_alloc"] }
+bytes    = { workspace = true }
 cfg-if   = { workspace = true }
 # FIXME:
 # We only need the `thread` feature if `service` is enabled.

database/README.md

@@ -79,10 +79,8 @@ The top-level `src/` files.
 | `storable.rs`       | Data (de)serialization; `trait Storable`
 | `table.rs`          | Database table abstraction; `trait Table`
 | `tables.rs`         | All the table definitions used by `cuprate-database`
-| `to_owned_debug.rs` | Borrowed/owned data abstraction; `trait ToOwnedDebug`
 | `transaction.rs`    | Database transaction abstraction; `trait TxR{o,w}`
 | `types.rs`          | Database table schema types
-| `value_guard.rs`    | Database value "guard" abstraction; `trait ValueGuard`
 
 ## `src/ops/`
 This folder contains the `cupate_database::ops` module.

database/src/backend/heed/database.rs

@@ -13,7 +13,6 @@ use crate::{
     database::{DatabaseRo, DatabaseRw},
     error::RuntimeError,
     table::Table,
-    value_guard::ValueGuard,
 };
 
 //---------------------------------------------------------------------------------------------------- Heed Database Wrappers
@@ -56,14 +55,12 @@ pub(super) struct HeedTableRw<'env, 'tx, T: Table> {
 
 /// Shared generic `get()` between `HeedTableR{o,w}`.
 #[inline]
-fn get<'a, T: Table>(
+fn get<T: Table>(
-    db: &'_ HeedDb<T::Key, T::Value>,
+    db: &HeedDb<T::Key, T::Value>,
-    tx_ro: &'a heed::RoTxn<'_>,
+    tx_ro: &heed::RoTxn<'_>,
     key: &T::Key,
-) -> Result<impl ValueGuard<T::Value> + 'a, RuntimeError> {
+) -> Result<T::Value, RuntimeError> {
-    db.get(tx_ro, key)?
+    db.get(tx_ro, key)?.ok_or(RuntimeError::KeyNotFound)
-        .map(Cow::Borrowed)
-        .ok_or(RuntimeError::KeyNotFound)
 }
 
 /// Shared generic `get_range()` between `HeedTableR{o,w}`.
@@ -71,29 +68,26 @@ fn get<'a, T: Table>(
 fn get_range<'a, T: Table, Range>(
     db: &'a HeedDb<T::Key, T::Value>,
     tx_ro: &'a heed::RoTxn<'_>,
-    range: &'a Range,
+    range: Range,
-) -> Result<impl Iterator<Item = Result<impl ValueGuard<T::Value> + 'a, RuntimeError>>, RuntimeError>
+) -> Result<impl Iterator<Item = Result<T::Value, RuntimeError>> + 'a, RuntimeError>
 where
     Range: RangeBounds<T::Key> + 'a,
 {
-    Ok(db.range(tx_ro, range)?.map(|res| Ok(Cow::Borrowed(res?.1))))
+    Ok(db.range(tx_ro, &range)?.map(|res| Ok(res?.1)))
 }
 
 //---------------------------------------------------------------------------------------------------- DatabaseRo Impl
 impl<'tx, T: Table> DatabaseRo<'tx, T> for HeedTableRo<'tx, T> {
     #[inline]
-    fn get<'a>(&'a self, key: &'a T::Key) -> Result<impl ValueGuard<T::Value> + 'a, RuntimeError> {
+    fn get(&self, key: &T::Key) -> Result<T::Value, RuntimeError> {
         get::<T>(&self.db, self.tx_ro, key)
     }
 
     #[inline]
     fn get_range<'a, Range>(
         &'a self,
-        range: &'a Range,
+        range: Range,
-    ) -> Result<
+    ) -> Result<impl Iterator<Item = Result<T::Value, RuntimeError>> + 'a, RuntimeError>
-        impl Iterator<Item = Result<impl ValueGuard<T::Value> + 'a, RuntimeError>>,
-        RuntimeError,
-    >
     where
         Range: RangeBounds<T::Key> + 'a,
     {
@@ -104,18 +98,15 @@ impl<'tx, T: Table> DatabaseRo<'tx, T> for HeedTableRo<'tx, T> {
 //---------------------------------------------------------------------------------------------------- DatabaseRw Impl
 impl<'tx, T: Table> DatabaseRo<'tx, T> for HeedTableRw<'_, 'tx, T> {
     #[inline]
-    fn get<'a>(&'a self, key: &'a T::Key) -> Result<impl ValueGuard<T::Value> + 'a, RuntimeError> {
+    fn get(&self, key: &T::Key) -> Result<T::Value, RuntimeError> {
         get::<T>(&self.db, self.tx_rw, key)
     }
 
     #[inline]
     fn get_range<'a, Range>(
         &'a self,
-        range: &'a Range,
+        range: Range,
-    ) -> Result<
+    ) -> Result<impl Iterator<Item = Result<T::Value, RuntimeError>> + 'a, RuntimeError>
-        impl Iterator<Item = Result<impl ValueGuard<T::Value> + 'a, RuntimeError>>,
-        RuntimeError,
-    >
     where
         Range: RangeBounds<T::Key> + 'a,
     {

database/src/backend/heed/storable.rs

@@ -5,7 +5,7 @@ use std::{borrow::Cow, fmt::Debug, marker::PhantomData};
 
 use heed::{types::Bytes, BoxedError, BytesDecode, BytesEncode, Database};
 
-use crate::storable::Storable;
+use crate::{storable::Storable, storable::StorableVec};
 
 //---------------------------------------------------------------------------------------------------- StorableHeed
 /// The glue struct that implements `heed`'s (de)serialization
@@ -19,9 +19,9 @@ where
 //---------------------------------------------------------------------------------------------------- BytesDecode
 impl<'a, T> BytesDecode<'a> for StorableHeed<T>
 where
-    T: Storable + ?Sized + 'a,
+    T: Storable + 'static,
 {
-    type DItem = &'a T;
+    type DItem = T;
 
     #[inline]
     /// This function is infallible (will always return `Ok`).
@@ -47,9 +47,8 @@ where
 //---------------------------------------------------------------------------------------------------- Tests
 #[cfg(test)]
 mod test {
-    use std::fmt::Debug;
-
     use super::*;
+    use crate::{StorableBytes, StorableVec};
 
     // Each `#[test]` function has a `test()` to:
     // - log
@@ -79,7 +78,8 @@ mod test {
         test::<i16>(&-2, &[254, 255]);
         test::<i32>(&-3, &[253, 255, 255, 255]);
         test::<i64>(&-4, &[252, 255, 255, 255, 255, 255, 255, 255]);
-        test::<[u8]>(&[1, 2], &[1, 2]);
+        test::<StorableVec<u8>>(&StorableVec(vec![1, 2]), &[1, 2]);
+        test::<StorableBytes>(&StorableBytes(bytes::Bytes::from_static(&[1, 2])), &[1, 2]);
         test::<[u8; 0]>(&[], &[]);
         test::<[u8; 1]>(&[255], &[255]);
         test::<[u8; 2]>(&[111, 0], &[111, 0]);
@@ -91,12 +91,12 @@ mod test {
     fn bytes_decode() {
         fn test<T>(bytes: &[u8], expected: &T)
         where
-            T: Storable + ?Sized + PartialEq + ToOwned + Debug,
+            T: Storable + PartialEq + ToOwned + Debug + 'static,
             T::Owned: Debug,
         {
             println!("bytes: {bytes:?}, expected: {expected:?}");
             assert_eq!(
-                <StorableHeed::<T> as BytesDecode>::bytes_decode(bytes).unwrap(),
+                &<StorableHeed::<T> as BytesDecode>::bytes_decode(bytes).unwrap(),
                 expected
             );
         }
@@ -110,7 +110,8 @@ mod test {
         test::<i16>([254, 255].as_slice(), &-2);
         test::<i32>([253, 255, 255, 255].as_slice(), &-3);
         test::<i64>([252, 255, 255, 255, 255, 255, 255, 255].as_slice(), &-4);
-        test::<[u8]>([1, 2].as_slice(), &[1, 2]);
+        test::<StorableVec<u8>>(&[1, 2], &StorableVec(vec![1, 2]));
+        test::<StorableBytes>(&[1, 2], &StorableBytes(bytes::Bytes::from_static(&[1, 2])));
         test::<[u8; 0]>([].as_slice(), &[]);
         test::<[u8; 1]>([255].as_slice(), &[255]);
         test::<[u8; 2]>([111, 0].as_slice(), &[111, 0]);

database/src/backend/redb/database.rs

@@ -17,8 +17,6 @@ use crate::{
     error::RuntimeError,
     storable::Storable,
     table::Table,
-    value_guard::ValueGuard,
-    ToOwnedDebug,
 };
 
 //---------------------------------------------------------------------------------------------------- Shared functions
@@ -28,108 +26,40 @@ use crate::{
 
 /// Shared generic `get()` between `RedbTableR{o,w}`.
 #[inline]
-fn get<'a, T: Table + 'static>(
+fn get<T: Table + 'static>(
-    db: &'a impl redb::ReadableTable<StorableRedb<T::Key>, StorableRedb<T::Value>>,
+    db: &impl redb::ReadableTable<StorableRedb<T::Key>, StorableRedb<T::Value>>,
-    key: &'a T::Key,
+    key: &T::Key,
-) -> Result<impl ValueGuard<T::Value> + 'a, RuntimeError> {
+) -> Result<T::Value, RuntimeError> {
-    db.get(Cow::Borrowed(key))?.ok_or(RuntimeError::KeyNotFound)
+    Ok(db.get(key)?.ok_or(RuntimeError::KeyNotFound)?.value())
 }
 
 /// Shared generic `get_range()` between `RedbTableR{o,w}`.
 #[inline]
 fn get_range<'a, T: Table, Range>(
     db: &'a impl redb::ReadableTable<StorableRedb<T::Key>, StorableRedb<T::Value>>,
-    range: &'a Range,
+    range: Range,
-) -> Result<
+) -> Result<impl Iterator<Item = Result<T::Value, RuntimeError>> + 'a, RuntimeError>
-    impl Iterator<Item = Result<redb::AccessGuard<'a, StorableRedb<T::Value>>, RuntimeError>> + 'a,
-    RuntimeError,
->
 where
     Range: RangeBounds<T::Key> + 'a,
 {
-    /// HACK: `redb` sees the database's key type as `Cow<'_, T::Key>`,
-    /// not `T::Key` directly like `heed` does. As such, it wants the
-    /// range to be over `Cow<'_, T::Key>`, not `T::Key` directly.
-    ///
-    /// If `DatabaseRo` were to want `Cow<'_, T::Key>` as input in `get()`,
-    /// `get_range()`, it would complicate the API:
-    /// ```rust,ignore
-    /// // This would be needed...
-    /// let range = Cow::Owned(0)..Cow::Owned(1);
-    /// // ...instead of the more obvious
-    /// let range = 0..1;
-    /// ```
-    ///
-    /// As such, `DatabaseRo` only wants `RangeBounds<T::Key>` and
-    /// we create a compatibility struct here, essentially converting
-    /// this functions input:
-    /// ```rust,ignore
-    /// RangeBound<T::Key>
-    /// ```
-    /// into `redb`'s desired:
-    /// ```rust,ignore
-    /// RangeBound<Cow<'_, T::Key>>
-    /// ```
-    struct CowRange<'a, K>
-    where
-        K: ToOwnedDebug,
-    {
-        /// The start bound of `Range`.
-        start_bound: Bound<Cow<'a, K>>,
-        /// The end bound of `Range`.
-        end_bound: Bound<Cow<'a, K>>,
-    }
-
-    /// This impl forwards our `T::Key` to be wrapped in a Cow.
-    impl<'a, K> RangeBounds<Cow<'a, K>> for CowRange<'a, K>
-    where
-        K: ToOwnedDebug,
-    {
-        fn start_bound(&self) -> Bound<&Cow<'a, K>> {
-            self.start_bound.as_ref()
-        }
-
-        fn end_bound(&self) -> Bound<&Cow<'a, K>> {
-            self.end_bound.as_ref()
-        }
-    }
-
-    let start_bound = match range.start_bound() {
-        Bound::Included(t) => Bound::Included(Cow::Borrowed(t)),
-        Bound::Excluded(t) => Bound::Excluded(Cow::Borrowed(t)),
-        Bound::Unbounded => Bound::Unbounded,
-    };
-    let end_bound = match range.end_bound() {
-        Bound::Included(t) => Bound::Included(Cow::Borrowed(t)),
-        Bound::Excluded(t) => Bound::Excluded(Cow::Borrowed(t)),
-        Bound::Unbounded => Bound::Unbounded,
-    };
-    let range = CowRange {
-        start_bound,
-        end_bound,
-    };
-
     Ok(db.range(range)?.map(|result| {
         let (_key, value_guard) = result?;
-        Ok(value_guard)
+        Ok(value_guard.value())
     }))
 }
 
 //---------------------------------------------------------------------------------------------------- DatabaseRo
 impl<'tx, T: Table + 'static> DatabaseRo<'tx, T> for RedbTableRo<'tx, T::Key, T::Value> {
     #[inline]
-    fn get<'a>(&'a self, key: &'a T::Key) -> Result<impl ValueGuard<T::Value> + 'a, RuntimeError> {
+    fn get(&self, key: &T::Key) -> Result<T::Value, RuntimeError> {
         get::<T>(self, key)
     }
 
     #[inline]
     fn get_range<'a, Range>(
         &'a self,
-        range: &'a Range,
+        range: Range,
-    ) -> Result<
+    ) -> Result<impl Iterator<Item = Result<T::Value, RuntimeError>> + 'a, RuntimeError>
-        impl Iterator<Item = Result<impl ValueGuard<T::Value>, RuntimeError>> + 'a,
-        RuntimeError,
-    >
     where
         Range: RangeBounds<T::Key> + 'a,
     {
@@ -140,18 +70,15 @@ impl<'tx, T: Table + 'static> DatabaseRo<'tx, T> for RedbTableRo<'tx, T::Key, T:
 //---------------------------------------------------------------------------------------------------- DatabaseRw
 impl<'tx, T: Table + 'static> DatabaseRo<'tx, T> for RedbTableRw<'_, 'tx, T::Key, T::Value> {
     #[inline]
-    fn get<'a>(&'a self, key: &'a T::Key) -> Result<impl ValueGuard<T::Value> + 'a, RuntimeError> {
+    fn get(&self, key: &T::Key) -> Result<T::Value, RuntimeError> {
         get::<T>(self, key)
     }
 
     #[inline]
     fn get_range<'a, Range>(
         &'a self,
-        range: &'a Range,
+        range: Range,
-    ) -> Result<
+    ) -> Result<impl Iterator<Item = Result<T::Value, RuntimeError>> + 'a, RuntimeError>
-        impl Iterator<Item = Result<impl ValueGuard<T::Value>, RuntimeError>> + 'a,
-        RuntimeError,
-    >
     where
         Range: RangeBounds<T::Key> + 'a,
     {
@@ -167,13 +94,13 @@ impl<'env, 'tx, T: Table + 'static> DatabaseRw<'env, 'tx, T>
 
     #[inline]
     fn put(&mut self, key: &T::Key, value: &T::Value) -> Result<(), RuntimeError> {
-        self.insert(Cow::Borrowed(key), Cow::Borrowed(value))?;
+        self.insert(key, value)?;
         Ok(())
     }
 
     #[inline]
     fn delete(&mut self, key: &T::Key) -> Result<(), RuntimeError> {
-        self.remove(Cow::Borrowed(key))?;
+        self.remove(key)?;
         Ok(())
     }
 }

database/src/backend/redb/storable.rs

@@ -5,7 +5,7 @@ use std::{any::Any, borrow::Cow, cmp::Ordering, fmt::Debug, marker::PhantomData}
 
 use redb::{RedbKey, RedbValue, TypeName};
 
-use crate::{key::Key, storable::Storable, value_guard::ValueGuard};
+use crate::{key::Key, storable::Storable};
 
 //---------------------------------------------------------------------------------------------------- StorableRedb
 /// The glue structs that implements `redb`'s (de)serialization
@@ -15,27 +15,13 @@ use crate::{key::Key, storable::Storable, value_guard::ValueGuard};
 #[derive(Debug)]
 pub(super) struct StorableRedb<T>(PhantomData<T>)
 where
-    T: Storable + ?Sized;
+    T: Storable;
-
-impl<T: Storable + ?Sized> ValueGuard<T> for redb::AccessGuard<'_, StorableRedb<T>> {
-    #[inline]
-    fn unguard(&self) -> Cow<'_, T> {
-        self.value()
-    }
-}
-
-impl<T: Storable + ?Sized> ValueGuard<T> for &redb::AccessGuard<'_, StorableRedb<T>> {
-    #[inline]
-    fn unguard(&self) -> Cow<'_, T> {
-        self.value()
-    }
-}
 
 //---------------------------------------------------------------------------------------------------- RedbKey
 // If `Key` is also implemented, this can act as a `RedbKey`.
 impl<T> RedbKey for StorableRedb<T>
 where
-    T: Key + ?Sized,
+    T: Key + 'static,
 {
     #[inline]
     fn compare(left: &[u8], right: &[u8]) -> Ordering {
@@ -46,9 +32,9 @@ where
 //---------------------------------------------------------------------------------------------------- RedbValue
 impl<T> RedbValue for StorableRedb<T>
 where
-    T: Storable + ?Sized,
+    T: Storable + 'static,
 {
-    type SelfType<'a> = Cow<'a, T> where Self: 'a;
+    type SelfType<'a> = T where Self: 'a;
     type AsBytes<'a> = &'a [u8] where Self: 'a;
 
     #[inline]
@@ -57,18 +43,11 @@ where
     }
 
     #[inline]
-    fn from_bytes<'a>(data: &'a [u8]) -> Self::SelfType<'a>
+    fn from_bytes<'a>(data: &'a [u8]) -> Self::SelfType<'static>
     where
         Self: 'a,
     {
-        // Use the bytes directly if possible...
+        <T as Storable>::from_bytes(data)
-        if T::ALIGN == 1 {
-            Cow::Borrowed(<T as Storable>::from_bytes(data))
-        // ...else, make sure the bytes are aligned
-        // when casting by allocating a new buffer.
-        } else {
-            <T as Storable>::from_bytes_unaligned(data)
-        }
     }
 
     #[inline]
@@ -76,7 +55,7 @@ where
     where
         Self: 'a + 'b,
     {
-        <T as Storable>::as_bytes(value.as_ref())
+        <T as Storable>::as_bytes(value)
     }
 
     #[inline]
@@ -90,6 +69,7 @@ where
 #[allow(clippy::needless_pass_by_value)]
 mod test {
     use super::*;
+    use crate::{StorableBytes, StorableVec};
 
     // Each `#[test]` function has a `test()` to:
     // - log
@@ -101,13 +81,13 @@ mod test {
     fn compare() {
         fn test<T>(left: T, right: T, expected: Ordering)
         where
-            T: Key,
+            T: Key + 'static,
         {
             println!("left: {left:?}, right: {right:?}, expected: {expected:?}");
             assert_eq!(
                 <StorableRedb::<T> as RedbKey>::compare(
-                    <StorableRedb::<T> as RedbValue>::as_bytes(&Cow::Borrowed(&left)),
+                    <StorableRedb::<T> as RedbValue>::as_bytes(&left),
-                    <StorableRedb::<T> as RedbValue>::as_bytes(&Cow::Borrowed(&right))
+                    <StorableRedb::<T> as RedbValue>::as_bytes(&right)
                 ),
                 expected
             );
@@ -124,7 +104,7 @@ mod test {
     fn fixed_width() {
         fn test<T>(expected: Option<usize>)
         where
-            T: Storable + ?Sized,
+            T: Storable + 'static,
         {
             assert_eq!(<StorableRedb::<T> as RedbValue>::fixed_width(), expected);
         }
@@ -138,7 +118,8 @@ mod test {
         test::<i16>(Some(2));
         test::<i32>(Some(4));
         test::<i64>(Some(8));
-        test::<[u8]>(None);
+        test::<StorableVec<u8>>(None);
+        test::<StorableBytes>(None);
         test::<[u8; 0]>(Some(0));
         test::<[u8; 1]>(Some(1));
         test::<[u8; 2]>(Some(2));
@@ -150,13 +131,10 @@ mod test {
     fn as_bytes() {
         fn test<T>(t: &T, expected: &[u8])
         where
-            T: Storable + ?Sized,
+            T: Storable + 'static,
         {
             println!("t: {t:?}, expected: {expected:?}");
-            assert_eq!(
+            assert_eq!(<StorableRedb::<T> as RedbValue>::as_bytes(t), expected);
-                <StorableRedb::<T> as RedbValue>::as_bytes(&Cow::Borrowed(t)),
-                expected
-            );
         }
 
         test::<()>(&(), &[]);
@@ -168,7 +146,8 @@ mod test {
         test::<i16>(&-2, &[254, 255]);
         test::<i32>(&-3, &[253, 255, 255, 255]);
         test::<i64>(&-4, &[252, 255, 255, 255, 255, 255, 255, 255]);
-        test::<[u8]>(&[1, 2], &[1, 2]);
+        test::<StorableVec<u8>>(&StorableVec([1, 2].to_vec()), &[1, 2]);
+        test::<StorableBytes>(&StorableBytes(bytes::Bytes::from_static(&[1, 2])), &[1, 2]);
         test::<[u8; 0]>(&[], &[]);
         test::<[u8; 1]>(&[255], &[255]);
         test::<[u8; 2]>(&[111, 0], &[111, 0]);
@@ -180,12 +159,12 @@ mod test {
     fn from_bytes() {
         fn test<T>(bytes: &[u8], expected: &T)
         where
-            T: Storable + PartialEq + ?Sized,
+            T: Storable + PartialEq + 'static,
         {
             println!("bytes: {bytes:?}, expected: {expected:?}");
             assert_eq!(
-                <StorableRedb::<T> as RedbValue>::from_bytes(bytes),
+                &<StorableRedb::<T> as RedbValue>::from_bytes(bytes),
-                Cow::Borrowed(expected)
+                expected
             );
         }
 
@@ -198,7 +177,8 @@ mod test {
         test::<i16>([254, 255].as_slice(), &-2);
         test::<i32>([253, 255, 255, 255].as_slice(), &-3);
         test::<i64>([252, 255, 255, 255, 255, 255, 255, 255].as_slice(), &-4);
-        test::<[u8]>([1, 2].as_slice(), &[1, 2]);
+        test::<StorableVec<u8>>(&[1, 2], &StorableVec(vec![1, 2]));
+        test::<StorableBytes>(&[1, 2], &StorableBytes(bytes::Bytes::from_static(&[1, 2])));
         test::<[u8; 0]>([].as_slice(), &[]);
         test::<[u8; 1]>([255].as_slice(), &[255]);
         test::<[u8; 2]>([111, 0].as_slice(), &[111, 0]);
@@ -221,7 +201,8 @@ mod test {
             <StorableRedb<i16> as RedbValue>::type_name(),
             <StorableRedb<i32> as RedbValue>::type_name(),
             <StorableRedb<i64> as RedbValue>::type_name(),
-            <StorableRedb<[u8]> as RedbValue>::type_name(),
+            <StorableRedb<StorableVec<u8>> as RedbValue>::type_name(),
+            <StorableRedb<StorableBytes> as RedbValue>::type_name(),
             <StorableRedb<[u8; 0]> as RedbValue>::type_name(),
             <StorableRedb<[u8; 1]> as RedbValue>::type_name(),
             <StorableRedb<[u8; 2]> as RedbValue>::type_name(),

database/src/backend/tests.rs

@@ -24,6 +24,7 @@ use crate::{
     env::{Env, EnvInner},
     error::{InitError, RuntimeError},
     resize::ResizeAlgorithm,
+    storable::StorableVec,
     table::Table,
     tables::{
         BlockBlobs, BlockHeights, BlockInfoV1s, BlockInfoV2s, BlockInfoV3s, KeyImages, NumOutputs,
@@ -36,7 +37,6 @@ use crate::{
         BlockInfoV2, BlockInfoV3, KeyImage, Output, PreRctOutputId, PrunableBlob, PrunableHash,
         PrunedBlob, RctOutput, TxHash, TxId, UnlockTime,
     },
-    value_guard::ValueGuard,
     ConcreteEnv,
 };
 
@@ -181,10 +181,10 @@ fn db_read_write() {
         tx_idx: 2_353_487,
     };
 
-    /// Assert a passed `Output` is equal to the const value.
+    /// Assert 2 `Output`'s are equal, and that accessing
-    fn assert_eq(output: &Output) {
+    /// their fields don't result in an unaligned panic.
-        assert_eq!(output, &VALUE);
+    fn assert_same(output: Output) {
-        // Make sure all field accesses are aligned.
+        assert_eq!(output, VALUE);
         assert_eq!(output.key, VALUE.key);
         assert_eq!(output.height, VALUE.height);
         assert_eq!(output.output_flags, VALUE.output_flags);
@@ -200,31 +200,47 @@ fn db_read_write() {
 
     // Assert the 1st key is there.
     {
-        let guard = table.get(&KEY).unwrap();
+        let value: Output = table.get(&KEY).unwrap();
-        let cow: Cow<'_, Output> = guard.unguard();
+        assert_same(value);
-        let value: &Output = cow.as_ref();
-        assert_eq(value);
     }
 
     // Assert the whole range is there.
     {
-        let range = table.get_range(&..).unwrap();
+        let range = table.get_range(..).unwrap();
         let mut i = 0;
         for result in range {
-            let guard = result.unwrap();
+            let value: Output = result.unwrap();
-            let cow: Cow<'_, Output> = guard.unguard();
+            assert_same(value);
-            let value: &Output = cow.as_ref();
+
-            assert_eq(value);
             i += 1;
         }
         assert_eq!(i, 100);
     }
 
-    // Assert `get_range()` works.
+    // `get_range()` tests.
     let mut key = KEY;
     key.amount += 100;
     let range = KEY..key;
-    assert_eq!(100, table.get_range(&range).unwrap().count());
+
+    // Assert count is correct.
+    assert_eq!(100, table.get_range(range.clone()).unwrap().count());
+
+    // Assert each returned value from the iterator is owned.
+    {
+        let mut iter = table.get_range(range.clone()).unwrap();
+        let value: Output = iter.next().unwrap().unwrap(); // 1. take value out
+        drop(iter); // 2. drop the `impl Iterator + 'a`
+        assert_same(value); // 3. assert even without the iterator, the value is alive
+    }
+
+    // Assert each value is the same.
+    {
+        let mut iter = table.get_range(range).unwrap();
+        for _ in 0..100 {
+            let value: Output = iter.next().unwrap().unwrap();
+            assert_same(value);
+        }
+    }
 
     // Assert deleting works.
     table.delete(&KEY).unwrap();
@@ -261,33 +277,29 @@ macro_rules! test_tables {
 
             /// The expected key.
             const KEY: $key_type = $key;
-            /// The expected value.
+            // The expected value.
-            const VALUE: &$value_type = &$value;
+            let value: $value_type = $value;
 
-            /// Assert a passed value is equal to the const value.
+            // Assert a passed value is equal to the const value.
-            fn assert_eq(value: &$value_type) {
+            let assert_eq = |v: &$value_type| {
-                assert_eq!(value, VALUE);
+                assert_eq!(v, &value);
-            }
+            };
 
             // Insert the key.
-            table.put(&KEY, VALUE).unwrap();
+            table.put(&KEY, &value).unwrap();
             // Assert key is there.
             {
-                let guard = table.get(&KEY).unwrap();
+                let value: $value_type = table.get(&KEY).unwrap();
-                let cow: Cow<'_, $value_type> = guard.unguard();
+                assert_eq(&value);
-                let value: &$value_type = cow.as_ref();
-                assert_eq(value);
             }
 
             // Assert `get_range()` works.
             {
                 let range = KEY..;
-                assert_eq!(1, table.get_range(&range).unwrap().count());
+                assert_eq!(1, table.get_range(range.clone()).unwrap().count());
-                let mut iter = table.get_range(&range).unwrap();
+                let mut iter = table.get_range(range).unwrap();
-                let guard = iter.next().unwrap().unwrap();
+                let value = iter.next().unwrap().unwrap();
-                let cow = guard.unguard();
+                assert_eq(&value);
-                let value = cow.as_ref();
-                assert_eq(value);
             }
 
             // Assert deleting works.
@@ -303,7 +315,7 @@ macro_rules! test_tables {
 test_tables! {
     BlockBlobs, // Table type
     BlockHeight => BlockBlob, // Key type => Value type
-    123 => [1,2,3,4,5,6,7,8].as_slice(), // Actual key => Actual value
+    123 => StorableVec(vec![1,2,3,4,5,6,7,8]), // Actual key => Actual value
 
     BlockHeights,
     BlockHash => BlockHeight,
@@ -377,11 +389,11 @@ test_tables! {
 
     PrunedTxBlobs,
     TxId => PrunedBlob,
-    123 => [1,2,3,4,5,6,7,8].as_slice(),
+    123 => StorableVec(vec![1,2,3,4,5,6,7,8]),
 
     PrunableTxBlobs,
     TxId => PrunableBlob,
-    123 => [1,2,3,4,5,6,7,8].as_slice(),
+    123 => StorableVec(vec![1,2,3,4,5,6,7,8]),
 
     PrunableHashes,
     TxId => PrunableHash,

database/src/database.rs

@@ -11,7 +11,6 @@ use crate::{
     error::RuntimeError,
     table::Table,
     transaction::{TxRo, TxRw},
-    value_guard::ValueGuard,
 };
 
 //---------------------------------------------------------------------------------------------------- DatabaseRo
@@ -22,19 +21,18 @@ use crate::{
 pub trait DatabaseRo<'tx, T: Table> {
     /// Get the value corresponding to a key.
     ///
-    /// This returns a guard to the value, not the value itself.
+    /// The returned value is _owned_.
-    /// See [`ValueGuard`] for more info.
     ///
     /// # Errors
     /// This will return [`RuntimeError::KeyNotFound`] wrapped in [`Err`] if `key` does not exist.
     ///
     /// It will return other [`RuntimeError`]'s on things like IO errors as well.
-    fn get<'a>(&'a self, key: &'a T::Key) -> Result<impl ValueGuard<T::Value> + 'a, RuntimeError>;
+    fn get(&self, key: &T::Key) -> Result<T::Value, RuntimeError>;
 
     /// Get an iterator of values corresponding to a range of keys.
     ///
-    /// This returns guards to the values, not the values themselves.
+    /// Although the returned iterator itself is tied to the lifetime
-    /// See [`ValueGuard`] for more info.
+    /// of `&'a self`, the returned values from the iterator are _owned_.
     ///
     /// # Errors
     /// Each key in the `range` has the potential to error, for example,
@@ -43,11 +41,8 @@ pub trait DatabaseRo<'tx, T: Table> {
     /// from the iterator.
     fn get_range<'a, Range>(
         &'a self,
-        range: &'a Range,
+        range: Range,
-    ) -> Result<
+    ) -> Result<impl Iterator<Item = Result<T::Value, RuntimeError>> + 'a, RuntimeError>
-        impl Iterator<Item = Result<impl ValueGuard<T::Value>, RuntimeError>> + 'a,
-        RuntimeError,
-    >
     where
         Range: RangeBounds<T::Key> + 'a;
 }

database/src/key.rs

@@ -5,10 +5,7 @@ use std::{cmp::Ordering, fmt::Debug};
 
 use bytemuck::Pod;
 
-use crate::{
+use crate::storable::{self, Storable};
-    storable::{self, Storable},
-    ToOwnedDebug,
-};
 
 //---------------------------------------------------------------------------------------------------- Table
 /// Database [`Table`](crate::table::Table) key metadata.

database/src/lib.rs

@@ -129,7 +129,6 @@
 	redundant_semicolons,
 	unused_allocation,
 	coherence_leak_check,
-	single_use_lifetimes,
 	while_true,
 	clippy::missing_docs_in_private_items,
 
@@ -142,6 +141,7 @@
 	keyword_idents,
 	non_ascii_idents,
 	variant_size_differences,
+    single_use_lifetimes,
 
 	// Probably can be put into `#[deny]`.
 	future_incompatible,
@@ -240,7 +240,7 @@ pub use key::Key;
 mod macros;
 
 mod storable;
-pub use storable::Storable;
+pub use storable::{Storable, StorableBytes, StorableVec};
 
 pub mod ops;
 
@@ -254,12 +254,6 @@ pub mod types;
 mod transaction;
 pub use transaction::{TxRo, TxRw};
 
-mod to_owned_debug;
-pub use to_owned_debug::ToOwnedDebug;
-
-mod value_guard;
-pub use value_guard::ValueGuard;
-
 //---------------------------------------------------------------------------------------------------- Feature-gated
 #[cfg(feature = "service")]
 pub mod service;

database/src/storable.rs

@@ -2,16 +2,15 @@
 
 //---------------------------------------------------------------------------------------------------- Import
 use std::{
-    borrow::Cow,
+    borrow::{Borrow, Cow},
     char::ToLowercase,
     fmt::Debug,
     io::{Read, Write},
     sync::Arc,
 };
 
-use bytemuck::Pod;
+use bytemuck::{Pod, Zeroable};
-
+use bytes::Bytes;
-use crate::ToOwnedDebug;
 
 //---------------------------------------------------------------------------------------------------- Storable
 /// A type that can be stored in the database.
@@ -35,6 +34,8 @@ use crate::ToOwnedDebug;
 /// - All types in [`tables`](crate::tables)
 /// - Slices, e.g, `[T] where T: Storable`
 ///
+/// See [`StorableVec`] for storing slices of `T: Storable`.
+///
 /// ```rust
 /// # use cuprate_database::*;
 /// # use std::borrow::*;
@@ -45,7 +46,7 @@ use crate::ToOwnedDebug;
 /// assert_eq!(into, &[0; 8]);
 ///
 /// // From bytes.
-/// let from: u64 = *Storable::from_bytes(&into);
+/// let from: u64 = Storable::from_bytes(&into);
 /// assert_eq!(from, number);
 /// ```
 ///
@@ -62,36 +63,7 @@ use crate::ToOwnedDebug;
 ///
 /// Most likely, the bytes are little-endian, however
 /// that cannot be relied upon when using this trait.
-pub trait Storable: ToOwnedDebug {
+pub trait Storable: Debug {
-    /// What is the alignment of `Self`?
-    ///
-    /// For `[T]` types, this is set to the alignment of `T`.
-    ///
-    /// This is used to prevent copying when unneeded, e.g.
-    /// `[u8] -> [u8]` does not need to account for unaligned bytes,
-    /// since no cast needs to occur.
-    ///
-    /// # Examples
-    /// ```rust
-    /// # use cuprate_database::Storable;
-    /// assert_eq!(<()>::ALIGN, 1);
-    /// assert_eq!(u8::ALIGN, 1);
-    /// assert_eq!(u16::ALIGN, 2);
-    /// assert_eq!(u32::ALIGN, 4);
-    /// assert_eq!(u64::ALIGN, 8);
-    /// assert_eq!(i8::ALIGN, 1);
-    /// assert_eq!(i16::ALIGN, 2);
-    /// assert_eq!(i32::ALIGN, 4);
-    /// assert_eq!(i64::ALIGN, 8);
-    /// assert_eq!(<[u8]>::ALIGN, 1);
-    /// assert_eq!(<[u64]>::ALIGN, 8);
-    /// assert_eq!(<[u8; 0]>::ALIGN, 1);
-    /// assert_eq!(<[u8; 1]>::ALIGN, 1);
-    /// assert_eq!(<[u8; 2]>::ALIGN, 1);
-    /// assert_eq!(<[u64; 2]>::ALIGN, 8);
-    /// ```
-    const ALIGN: usize;
-
     /// Is this type fixed width in byte length?
     ///
     /// I.e., when converting `Self` to bytes, is it
@@ -113,7 +85,7 @@ pub trait Storable: ToOwnedDebug {
     ///
     /// # Examples
     /// ```rust
-    /// # use cuprate_database::Storable;
+    /// # use cuprate_database::*;
     /// assert_eq!(<()>::BYTE_LENGTH, Some(0));
     /// assert_eq!(u8::BYTE_LENGTH, Some(1));
     /// assert_eq!(u16::BYTE_LENGTH, Some(2));
@@ -123,46 +95,29 @@ pub trait Storable: ToOwnedDebug {
     /// assert_eq!(i16::BYTE_LENGTH, Some(2));
     /// assert_eq!(i32::BYTE_LENGTH, Some(4));
     /// assert_eq!(i64::BYTE_LENGTH, Some(8));
-    /// assert_eq!(<[u8]>::BYTE_LENGTH, None);
+    /// assert_eq!(StorableVec::<u8>::BYTE_LENGTH, None);
-    /// assert_eq!(<[u8; 0]>::BYTE_LENGTH, Some(0));
+    /// assert_eq!(StorableVec::<u64>::BYTE_LENGTH, None);
-    /// assert_eq!(<[u8; 1]>::BYTE_LENGTH, Some(1));
-    /// assert_eq!(<[u8; 2]>::BYTE_LENGTH, Some(2));
-    /// assert_eq!(<[u8; 3]>::BYTE_LENGTH, Some(3));
     /// ```
     const BYTE_LENGTH: Option<usize>;
 
     /// Return `self` in byte form.
     fn as_bytes(&self) -> &[u8];
 
-    /// Create a borrowed [`Self`] from bytes.
+    /// Create an owned [`Self`] from bytes.
-    ///
-    /// # Invariant
-    /// `bytes` must be perfectly aligned for `Self`
-    /// or else this function may cause UB.
-    ///
-    /// This function _may_ panic if `bytes` isn't aligned.
     ///
     /// # Blanket implementation
     /// The blanket implementation that covers all types used
-    /// by `cuprate_database` will simply cast `bytes` into `Self`,
+    /// by `cuprate_database` will simply bitwise copy `bytes`
-    /// with no copying.
+    /// into `Self`.
-    fn from_bytes(bytes: &[u8]) -> &Self;
-
-    /// Create a [`Self`] from potentially unaligned bytes.
     ///
-    /// # Blanket implementation
+    /// The bytes do not have be correctly aligned.
-    /// The blanket implementation that covers all types used
+    fn from_bytes(bytes: &[u8]) -> Self;
-    /// by `cuprate_database` will **always** allocate a new buffer
-    /// or create a new `Self`.
-    fn from_bytes_unaligned(bytes: &[u8]) -> Cow<'_, Self>;
 }
 
-//---------------------------------------------------------------------------------------------------- Impl
 impl<T> Storable for T
 where
-    Self: Pod + ToOwnedDebug<OwnedDebug = T>,
+    Self: Pod + Debug,
 {
-    const ALIGN: usize = std::mem::align_of::<T>();
     const BYTE_LENGTH: Option<usize> = Some(std::mem::size_of::<T>());
 
     #[inline]
@@ -171,37 +126,132 @@ where
     }
 
     #[inline]
-    fn from_bytes(bytes: &[u8]) -> &T {
+    fn from_bytes(bytes: &[u8]) -> T {
-        bytemuck::from_bytes(bytes)
+        bytemuck::pod_read_unaligned(bytes)
-    }
-
-    #[inline]
-    fn from_bytes_unaligned(bytes: &[u8]) -> Cow<'static, Self> {
-        Cow::Owned(bytemuck::pod_read_unaligned(bytes))
     }
 }
 
-impl<T> Storable for [T]
+//---------------------------------------------------------------------------------------------------- StorableVec
+/// A [`Storable`] vector of `T: Storable`.
+///
+/// This is a wrapper around `Vec<T> where T: Storable`.
+///
+/// Slice types are owned both:
+/// - when returned from the database
+/// - in `put()`
+///
+/// This is needed as `impl Storable for Vec<T>` runs into impl conflicts.
+///
+/// ```rust
+/// # use cuprate_database::*;
+/// //---------------------------------------------------- u8
+/// let vec: StorableVec<u8> = StorableVec(vec![0,1]);
+///
+/// // Into bytes.
+/// let into = Storable::as_bytes(&vec);
+/// assert_eq!(into, &[0,1]);
+///
+/// // From bytes.
+/// let from: StorableVec<u8> = Storable::from_bytes(&into);
+/// assert_eq!(from, vec);
+///
+/// //---------------------------------------------------- u64
+/// let vec: StorableVec<u64> = StorableVec(vec![0,1]);
+///
+/// // Into bytes.
+/// let into = Storable::as_bytes(&vec);
+/// assert_eq!(into, &[0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0]);
+///
+/// // From bytes.
+/// let from: StorableVec<u64> = Storable::from_bytes(&into);
+/// assert_eq!(from, vec);
+/// ```
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, bytemuck::TransparentWrapper)]
+#[repr(transparent)]
+pub struct StorableVec<T>(pub Vec<T>);
+
+impl<T> Storable for StorableVec<T>
 where
-    T: Pod + ToOwnedDebug<OwnedDebug = T>,
+    T: Pod + Debug,
-    Self: ToOwnedDebug<OwnedDebug = Vec<T>>,
 {
-    const ALIGN: usize = std::mem::align_of::<T>();
+    const BYTE_LENGTH: Option<usize> = None;
+
+    /// Casts the inner `Vec<T>` directly as bytes.
+    #[inline]
+    fn as_bytes(&self) -> &[u8] {
+        bytemuck::must_cast_slice(&self.0)
+    }
+
+    /// This always allocates a new `Vec<T>`,
+    /// casting `bytes` into a vector of type `T`.
+    #[inline]
+    fn from_bytes(bytes: &[u8]) -> Self {
+        Self(bytemuck::pod_collect_to_vec(bytes))
+    }
+}
+
+impl<T> std::ops::Deref for StorableVec<T> {
+    type Target = [T];
+    #[inline]
+    fn deref(&self) -> &[T] {
+        &self.0
+    }
+}
+
+impl<T> Borrow<[T]> for StorableVec<T> {
+    #[inline]
+    fn borrow(&self) -> &[T] {
+        &self.0
+    }
+}
+
+//---------------------------------------------------------------------------------------------------- StorableBytes
+/// A [`Storable`] version of [`Bytes`].
+///
+/// ```rust
+/// # use cuprate_database::*;
+/// # use bytes::Bytes;
+/// let bytes: StorableBytes = StorableBytes(Bytes::from_static(&[0,1]));
+///
+/// // Into bytes.
+/// let into = Storable::as_bytes(&bytes);
+/// assert_eq!(into, &[0,1]);
+///
+/// // From bytes.
+/// let from: StorableBytes = Storable::from_bytes(&into);
+/// assert_eq!(from, bytes);
+/// ```
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[repr(transparent)]
+pub struct StorableBytes(pub Bytes);
+
+impl Storable for StorableBytes {
     const BYTE_LENGTH: Option<usize> = None;
 
     #[inline]
     fn as_bytes(&self) -> &[u8] {
-        bytemuck::must_cast_slice(self)
+        &self.0
     }
 
+    /// This always allocates a new `Bytes`.
     #[inline]
-    fn from_bytes(bytes: &[u8]) -> &[T] {
+    fn from_bytes(bytes: &[u8]) -> Self {
-        bytemuck::cast_slice(bytes)
+        Self(Bytes::copy_from_slice(bytes))
+    }
 }
 
+impl std::ops::Deref for StorableBytes {
+    type Target = [u8];
     #[inline]
-    fn from_bytes_unaligned(bytes: &[u8]) -> Cow<'static, Self> {
+    fn deref(&self) -> &[u8] {
-        Cow::Owned(bytemuck::pod_collect_to_vec(bytes))
+        &self.0
+    }
+}
+
+impl Borrow<[u8]> for StorableBytes {
+    #[inline]
+    fn borrow(&self) -> &[u8] {
+        &self.0
     }
 }
 
@@ -220,7 +270,7 @@ mod test {
         // A `Vec` of the numbers to test.
         t: Vec<T>,
     ) where
-        T: Storable + Copy + PartialEq,
+        T: Storable + Debug + Copy + PartialEq,
     {
         for t in t {
             let expected_bytes = to_le_bytes(t);
@@ -229,7 +279,7 @@ mod test {
 
             // (De)serialize.
             let se: &[u8] = Storable::as_bytes(&t);
-            let de: &T = Storable::from_bytes(se);
+            let de = <T as Storable>::from_bytes(se);
 
             println!("serialized: {se:?}, deserialized: {de:?}\n");
 
@@ -238,7 +288,7 @@ mod test {
                 assert_eq!(se.len(), expected_bytes.len());
             }
             // Assert the data is the same.
-            assert_eq!(de, &t);
+            assert_eq!(de, t);
         }
     }
 

database/src/table.rs

@@ -3,7 +3,7 @@
 //---------------------------------------------------------------------------------------------------- Import
 use std::fmt::Debug;
 
-use crate::{key::Key, storable::Storable, to_owned_debug::ToOwnedDebug};
+use crate::{key::Key, storable::Storable};
 
 //---------------------------------------------------------------------------------------------------- Table
 /// Database table metadata.
@@ -19,10 +19,10 @@ pub trait Table: crate::tables::private::Sealed + 'static {
     const NAME: &'static str;
 
     /// Primary key type.
-    type Key: Key + ?Sized + 'static;
+    type Key: Key + 'static;
 
     /// Value type.
-    type Value: Storable + ?Sized + 'static;
+    type Value: Storable + 'static;
 }
 
 //---------------------------------------------------------------------------------------------------- Tests

database/src/to_owned_debug.rs

@@ -1,51 +0,0 @@
-//! Borrowed/owned data abstraction; `trait ToOwnedDebug`.
-
-//---------------------------------------------------------------------------------------------------- Import
-use std::fmt::Debug;
-
-use crate::{key::Key, storable::Storable};
-
-//---------------------------------------------------------------------------------------------------- Table
-/// `T: Debug` and `T::Owned: Debug`.
-///
-/// This trait simply combines [`Debug`] and [`ToOwned`]
-/// such that the `Owned` version must also be [`Debug`].
-///
-/// An example is `[u8]` which is [`Debug`], and
-/// its owned version `Vec<u8>` is also [`Debug`].
-///
-/// # Explanation (not needed for practical use)
-/// This trait solely exists due to the `redb` backend
-/// requiring [`Debug`] bounds on keys and values.
-///
-/// As we have `?Sized` types like `[u8]`, and due to `redb` requiring
-/// allocation upon deserialization, we must make our values `ToOwned`.
-///
-/// However, this requires that the `Owned` version is also `Debug`.
-/// Combined with:
-/// - [`Table::Key`](crate::Table::Key)
-/// - [`Table::Value`](crate::Table::Value)
-/// - [`Key::Primary`]
-///
-/// this quickly permutates into many many many `where` bounds on
-/// each function that touchs any data that must be deserialized.
-///
-/// This trait and the blanket impl it provides get applied all these types
-/// automatically, which means we don't have to write these bounds everywhere.
-pub trait ToOwnedDebug: Debug + ToOwned<Owned = Self::OwnedDebug> {
-    /// The owned version of [`Self`].
-    ///
-    /// Should be equal to `<T as ToOwned>::Owned`.
-    type OwnedDebug: Debug;
-}
-
-// The blanket impl that covers all our types.
-impl<O: Debug, T: ToOwned<Owned = O> + Debug + ?Sized> ToOwnedDebug for T {
-    type OwnedDebug = O;
-}
-
-//---------------------------------------------------------------------------------------------------- Tests
-#[cfg(test)]
-mod test {
-    // use super::*;
-}

database/src/types.rs

@@ -37,7 +37,6 @@
  */
 // actually i still don't trust you. no unsafe.
 #![forbid(unsafe_code)] // if you remove this line i will steal your monero
-#![allow(missing_docs)] // bytemuck auto-generates some non-documented structs
 
 //---------------------------------------------------------------------------------------------------- Import
 use bytemuck::{AnyBitPattern, NoUninit, Pod, Zeroable};
@@ -45,6 +44,8 @@ use bytemuck::{AnyBitPattern, NoUninit, Pod, Zeroable};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
+use crate::storable::StorableVec;
+
 //---------------------------------------------------------------------------------------------------- Aliases
 // TODO: document these, why they exist, and their purpose.
 //
@@ -58,10 +59,10 @@ pub type Amount = u64;
 pub type AmountIndex = u64;
 
 /// TODO
-pub type AmountIndices = [AmountIndex];
+pub type AmountIndices = StorableVec<AmountIndex>;
 
 /// TODO
-pub type BlockBlob = [u8];
+pub type BlockBlob = StorableVec<u8>;
 
 /// TODO
 pub type BlockHash = [u8; 32];
@@ -73,10 +74,10 @@ pub type BlockHeight = u64;
 pub type KeyImage = [u8; 32];
 
 /// TODO
-pub type PrunedBlob = [u8];
+pub type PrunedBlob = StorableVec<u8>;
 
 /// TODO
-pub type PrunableBlob = [u8];
+pub type PrunableBlob = StorableVec<u8>;
 
 /// TODO
 pub type PrunableHash = [u8; 32];
@@ -102,10 +103,8 @@ pub type UnlockTime = u64;
 ///     amount_index: 123,
 /// };
 /// let b = Storable::as_bytes(&a);
-/// let c: &PreRctOutputId = Storable::from_bytes(b);
+/// let c: PreRctOutputId = Storable::from_bytes(b);
-/// let c2: Cow<'_, PreRctOutputId> = Storable::from_bytes_unaligned(b);
+/// assert_eq!(a, c);
-/// assert_eq!(&a, c);
-/// assert_eq!(c, c2.as_ref());
 /// ```
 ///
 /// # Size & Alignment
@@ -140,10 +139,8 @@ pub struct PreRctOutputId {
 ///     block_hash: [54; 32],
 /// };
 /// let b = Storable::as_bytes(&a);
-/// let c: &BlockInfoV1 = Storable::from_bytes(b);
+/// let c: BlockInfoV1 = Storable::from_bytes(b);
-/// let c2: Cow<'_, BlockInfoV1> = Storable::from_bytes_unaligned(b);
+/// assert_eq!(a, c);
-/// assert_eq!(&a, c);
-/// assert_eq!(c, c2.as_ref());
 /// ```
 ///
 /// # Size & Alignment
@@ -185,10 +182,8 @@ pub struct BlockInfoV1 {
 ///     cumulative_rct_outs: 2389,
 /// };
 /// let b = Storable::as_bytes(&a);
-/// let c: &BlockInfoV2 = Storable::from_bytes(b);
+/// let c: BlockInfoV2 = Storable::from_bytes(b);
-/// let c2: Cow<'_, BlockInfoV2> = Storable::from_bytes_unaligned(b);
+/// assert_eq!(a, c);
-/// assert_eq!(&a, c);
-/// assert_eq!(c, c2.as_ref());
 /// ```
 ///
 /// # Size & Alignment
@@ -237,10 +232,8 @@ pub struct BlockInfoV2 {
 ///     long_term_weight: 2389,
 /// };
 /// let b = Storable::as_bytes(&a);
-/// let c: &BlockInfoV3 = Storable::from_bytes(b);
+/// let c: BlockInfoV3 = Storable::from_bytes(b);
-/// let c2: Cow<'_, BlockInfoV3> = Storable::from_bytes_unaligned(b);
+/// assert_eq!(a, c);
-/// assert_eq!(&a, c);
-/// assert_eq!(c, c2.as_ref());
 /// ```
 ///
 /// # Size & Alignment
@@ -287,10 +280,8 @@ pub struct BlockInfoV3 {
 ///     tx_idx: 3,
 /// };
 /// let b = Storable::as_bytes(&a);
-/// let c: &Output = Storable::from_bytes(b);
+/// let c: Output = Storable::from_bytes(b);
-/// let c2: Cow<'_, Output> = Storable::from_bytes_unaligned(b);
+/// assert_eq!(a, c);
-/// assert_eq!(&a, c);
-/// assert_eq!(c, c2.as_ref());
 /// ```
 ///
 /// # Size & Alignment
@@ -329,10 +320,8 @@ pub struct Output {
 ///     commitment: [3; 32],
 /// };
 /// let b = Storable::as_bytes(&a);
-/// let c: &RctOutput = Storable::from_bytes(b);
+/// let c: RctOutput = Storable::from_bytes(b);
-/// let c2: Cow<'_, RctOutput> = Storable::from_bytes_unaligned(b);
+/// assert_eq!(a, c);
-/// assert_eq!(&a, c);
-/// assert_eq!(c, c2.as_ref());
 /// ```
 ///
 /// # Size & Alignment

database/src/value_guard.rs

@@ -1,47 +0,0 @@
-//! Database table value "guard" abstraction; `trait ValueGuard`.
-
-//---------------------------------------------------------------------------------------------------- Import
-use std::borrow::{Borrow, Cow};
-
-use crate::{table::Table, Storable, ToOwnedDebug};
-
-//---------------------------------------------------------------------------------------------------- Table
-/// A guard that allows you to access a value.
-///
-/// This trait acts as an object that must be kept alive,
-/// and will give you access to a [`Table`]'s value.
-///
-/// # Explanation (not needed for practical use)
-/// This trait solely exists due to the `redb` backend
-/// not _directly_ returning the value, but a
-/// [guard object](https://docs.rs/redb/1.5.0/redb/struct.AccessGuard.html)
-/// that has a lifetime attached to the key.
-/// It does not implement `Deref` or `Borrow` and such.
-///
-/// Also, due to `redb` requiring `Cow`, this object builds on that.
-///
-/// - `heed` will always be `Cow::Borrowed`
-/// - `redb` will always be `Cow::Borrowed` for `[u8]`
-///   or any type where `Storable::ALIGN == 1`
-/// - `redb` will always be `Cow::Owned` for everything else
-pub trait ValueGuard<T: ToOwnedDebug + ?Sized> {
-    /// Retrieve the data from the guard.
-    fn unguard(&self) -> Cow<'_, T>;
-}
-
-impl<T: ToOwnedDebug + ?Sized> ValueGuard<T> for Cow<'_, T> {
-    #[inline]
-    fn unguard(&self) -> Cow<'_, T> {
-        Cow::Borrowed(self.borrow())
-    }
-}
-
-// HACK:
-// This is implemented for `redb::AccessGuard<'_>` in
-// `src/backend/redb/storable.rs` due to struct privacy.
-
-//---------------------------------------------------------------------------------------------------- Tests
-#[cfg(test)]
-mod test {
-    // use super::*;
-}