refactor: relocate vec types for benchmarks (#336)

This PR refactors the benchmarks to remove the dependency on test types
by introducing local copies of `UnboundedVecN` and `BoundedVecN`.

Copies of those types allow to run stable-structures version before
those types were introduced. This change was tested on stable-structures
v0.6.7.

Author: maksymar

benchmarks/btreemap/src/main.rs

@@ -1,10 +1,7 @@
-use benchmarks::common::Random;
+use benchmarks::{random::Random, vec::UnboundedVecN};
 use canbench_rs::{bench, bench_fn, BenchResult};
 use ic_stable_structures::memory_manager::{MemoryId, MemoryManager};
-use ic_stable_structures::{
-    storable::{Blob, UnboundedVecN},
-    BTreeMap, DefaultMemoryImpl, Memory, Storable,
-};
+use ic_stable_structures::{storable::Blob, BTreeMap, DefaultMemoryImpl, Memory, Storable};
 use std::ops::Bound;
 use tiny_rng::{Rand, Rng};
 

benchmarks/compare/src/main.rs

@@ -1,8 +1,8 @@
+use benchmarks::vec::BoundedVecN;
 use canbench_rs::{bench, bench_fn};
 use ic_cdk::api::stable::WASM_PAGE_SIZE_IN_BYTES;
 use ic_stable_structures::{
     memory_manager::{MemoryId, MemoryManager},
-    storable::BoundedVecN,
     BTreeMap, DefaultMemoryImpl, Memory, Vec as StableVec,
 };
 

benchmarks/src/lib.rs

@@ -1 +1,2 @@
-pub mod common;
+pub mod random;
+pub mod vec;

benchmarks/src/common.rs renamed to benchmarks/src/random.rs

@@ -1,4 +1,5 @@
-use ic_stable_structures::storable::{Blob, BoundedVecN, Storable, UnboundedVecN};
+use crate::vec::{BoundedVecN, UnboundedVecN};
+use ic_stable_structures::storable::{Blob, Storable};
 use tiny_rng::{Rand, Rng};
 
 pub trait Random {
@@ -20,7 +21,7 @@ impl<const K: usize> Random for Blob<K> {
 
 impl<const K: usize> Random for UnboundedVecN<K> {
     fn random(rng: &mut Rng) -> Self {
-        let size = rng.rand_u32() % Self::max_size();
+        let size = rng.rand_u32() % Self::MAX_SIZE;
         let mut buf = Vec::with_capacity(size as usize);
         for _ in 0..size {
             buf.push(rng.rand_u8());

benchmarks/src/vec.rs

@@ -0,0 +1,87 @@
+use ic_stable_structures::storable::{Bound, Storable};
+use std::borrow::Cow;
+
+/// Unbounded vector of bytes, always of length `N`.
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug)]
+pub struct UnboundedVecN<const N: usize>(Vec<u8>);
+
+impl<const N: usize> UnboundedVecN<N> {
+    pub const MAX_SIZE: u32 = N as u32;
+
+    pub fn from(slice: &[u8]) -> Self {
+        assert!(
+            slice.len() <= N,
+            "expected a slice with length <= {} bytes, but found {} bytes",
+            N,
+            slice.len()
+        );
+        let mut vec = Vec::with_capacity(N);
+        vec.extend_from_slice(slice);
+        vec.resize(N, 0);
+        Self(vec)
+    }
+}
+
+impl<const N: usize> Default for UnboundedVecN<N> {
+    fn default() -> Self {
+        Self(vec![0; N])
+    }
+}
+
+impl<const N: usize> Storable for UnboundedVecN<N> {
+    fn to_bytes(&self) -> Cow<[u8]> {
+        Cow::Owned(self.0.clone())
+    }
+
+    #[inline]
+    fn from_bytes(bytes: Cow<[u8]>) -> Self {
+        Self(bytes.into_owned())
+    }
+
+    const BOUND: Bound = Bound::Unbounded;
+}
+
+/// Bounded vector of bytes, always of length `N`.
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug)]
+pub struct BoundedVecN<const N: usize>(Vec<u8>);
+
+impl<const N: usize> BoundedVecN<N> {
+    pub fn max_size() -> u32 {
+        N as u32
+    }
+
+    pub fn from(slice: &[u8]) -> Self {
+        assert!(
+            slice.len() <= N,
+            "expected a slice with length <= {} bytes, but found {} bytes",
+            N,
+            slice.len()
+        );
+        let mut vec = Vec::with_capacity(N);
+        vec.extend_from_slice(slice);
+        vec.resize(N, 0);
+        Self(vec)
+    }
+}
+
+impl<const N: usize> Default for BoundedVecN<N> {
+    fn default() -> Self {
+        Self(vec![0; N])
+    }
+}
+
+impl<const N: usize> Storable for BoundedVecN<N> {
+    fn to_bytes(&self) -> Cow<[u8]> {
+        Cow::Owned(self.0.clone())
+    }
+
+    #[inline]
+    fn from_bytes(bytes: Cow<[u8]>) -> Self {
+        Self(bytes.into_owned())
+    }
+
+    const BOUND: Bound = Bound::Bounded {
+        max_size: N as u32,
+        is_fixed_size: false,
+    };
+}

benchmarks/vec/src/main.rs

@@ -1,4 +1,4 @@
-use benchmarks::common::Random;
+use benchmarks::random::Random;
 use canbench_rs::{bench, bench_fn, BenchResult};
 use ic_stable_structures::memory_manager::{MemoryId, MemoryManager};
 use ic_stable_structures::storable::Blob;

src/storable.rs

@@ -195,9 +195,7 @@ impl<const N: usize> Storable for Blob<N> {
 pub struct UnboundedVecN<const N: usize>(Vec<u8>);
 
 impl<const N: usize> UnboundedVecN<N> {
-    pub fn max_size() -> u32 {
-        N as u32
-    }
+    pub const MAX_SIZE: u32 = N as u32;
 
     pub fn from(slice: &[u8]) -> Self {
         assert!(
@@ -237,9 +235,7 @@ impl<const N: usize> Storable for UnboundedVecN<N> {
 pub struct BoundedVecN<const N: usize>(Vec<u8>);
 
 impl<const N: usize> BoundedVecN<N> {
-    pub fn max_size() -> u32 {
-        N as u32
-    }
+    pub const MAX_SIZE: u32 = N as u32;
 
     pub fn from(slice: &[u8]) -> Self {
         assert!(