vec: compression part 2 and done

crates/brk_vec/src/enums/mod.rs

@@ -1,5 +1,7 @@
 mod error;
 mod value;
+mod values;
 
 pub use error::*;
 pub use value::*;
+pub use values::*;

crates/brk_vec/src/enums/values.rs

@@ -0,0 +1,83 @@
+use std::ops::Range;
+
+use memmap2::Mmap;
+use zerocopy::{Immutable, IntoBytes, KnownLayout, TryFromBytes};
+
+use crate::MAX_PAGE_SIZE;
+
+use super::Result;
+
+#[derive(Debug)]
+pub enum Values<T> {
+    Owned(Box<[T]>),
+    Ref(Box<Mmap>),
+}
+
+impl<T> Values<T> {
+    const PER_PAGE: usize = MAX_PAGE_SIZE / Self::SIZE_OF_T;
+    const SIZE_OF_T: usize = size_of::<T>();
+
+    pub fn get(&self, index: usize) -> Result<Option<&T>>
+    where
+        T: TryFromBytes + IntoBytes + Immutable + KnownLayout,
+    {
+        let index = Self::index_to_decoded_index(index);
+
+        Ok(match self {
+            Self::Owned(a) => a.get(index),
+            Self::Ref(m) => {
+                let range = Self::index_to_byte_range(index);
+                let source = &m[range];
+                Some(T::try_ref_from_bytes(source)?)
+            }
+        })
+    }
+
+    pub fn as_arr(&self) -> &[T] {
+        match self {
+            Self::Owned(a) => a,
+            Self::Ref(_) => unreachable!(),
+        }
+    }
+
+    pub fn as_mmap(&self) -> &Mmap {
+        match self {
+            Self::Owned(_) => unreachable!(),
+            Self::Ref(m) => m,
+        }
+    }
+
+    #[inline]
+    fn index_to_byte_range(index: usize) -> Range<usize> {
+        let index = Self::index_to_byte_index(index) as usize;
+        index..(index + Self::SIZE_OF_T)
+    }
+
+    #[inline]
+    fn index_to_byte_index(index: usize) -> u64 {
+        (index * Self::SIZE_OF_T) as u64
+    }
+
+    #[inline(always)]
+    fn index_to_decoded_index(index: usize) -> usize {
+        index % Self::PER_PAGE
+    }
+}
+
+impl<T> From<Box<[T]>> for Values<T> {
+    fn from(value: Box<[T]>) -> Self {
+        Self::Owned(value)
+    }
+}
+
+impl<T> From<Mmap> for Values<T> {
+    fn from(value: Mmap) -> Self {
+        Self::Ref(Box::new(value))
+    }
+}
+
+impl<T> Default for Values<T> {
+    fn default() -> Self {
+        Self::Owned(vec![].into_boxed_slice())
+    }
+}

crates/brk_vec/src/structs/back.rs

@@ -1,20 +0,0 @@
-use std::{fs::File, sync::OnceLock};
-
-use super::CompressedPagesMetadata;
-
-type CompressedPage<T> = Option<(usize, Box<[T]>)>;
-
-pub enum Back<T> {
-    Raw {
-        raw_pages: Vec<OnceLock<Box<memmap2::Mmap>>>,
-        raw_page: memmap2::Mmap,
-        file: File,
-        file_position: u64,
-        buf: Vec<u8>,
-    },
-    Compressed {
-        decoded_pages: Option<Vec<OnceLock<Box<[T]>>>>,
-        decoded_page: CompressedPage<T>,
-        pages: CompressedPagesMetadata,
-    },
-}

crates/brk_vec/src/structs/mod.rs

@@ -1,15 +1,13 @@
-mod back;
 mod compressed;
+mod compressed_page_meta;
+mod compressed_pages_meta;
 mod length;
-mod page;
-mod pages;
 mod unsafe_slice;
 mod version;
 
-pub use back::*;
 pub use compressed::*;
+pub use compressed_page_meta::*;
+pub use compressed_pages_meta::*;
 pub use length::*;
-pub use page::*;
-pub use pages::*;
 pub use unsafe_slice::*;
 pub use version::*;

crates/brk_vec/src/traits/any.rs

@@ -9,7 +9,11 @@ pub trait AnyStorableVec: Send + Sync {
     fn index_type_to_string(&self) -> &str;
     fn len(&self) -> usize;
     fn is_empty(&self) -> bool;
-    fn collect_range_values(&self, from: Option<i64>, to: Option<i64>) -> Result<Vec<serde_json::Value>>;
+    fn collect_range_values(
+        &self,
+        from: Option<i64>,
+        to: Option<i64>,
+    ) -> Result<Vec<serde_json::Value>>;
     fn flush(&mut self) -> io::Result<()>;
 }
 
@@ -38,7 +42,11 @@ where
         self.flush()
     }
 
-    fn collect_range_values(&self, from: Option<i64>, to: Option<i64>) -> Result<Vec<serde_json::Value>> {
+    fn collect_range_values(
+        &self,
+        from: Option<i64>,
+        to: Option<i64>,
+    ) -> Result<Vec<serde_json::Value>> {
         Ok(self
             .collect_range(from, to)?
             .into_iter()