Merge #3001

3001: Implement Uuid codec for heed r=Kerollmops a=elbertronnie

# Pull Request

## Related issue
Fixes #2984 

## What does this PR do?
- Created a new heed codec for uuid::Uuid named as UuidCodec
- Replaced SerdeBincode\<Uuid\> with UuidCodec
- Removed the TODO in code associated with this issue

## PR checklist
Please check if your PR fulfills the following requirements:
- [x] Does this PR fix an existing issue, or have you listed the changes applied in the PR description (and why they are needed)?
- [x] Have you read the contributing guidelines?
- [x] Have you made sure that the title is accurate and descriptive of the changes?

Thank you so much for contributing to Meilisearch!


Co-authored-by: Elbert Ronnie <elbert.ronniep@gmail.com>

index-scheduler/src/index_mapper.rs

@@ -5,13 +5,14 @@ use std::sync::{Arc, RwLock};
 use std::{fs, thread};
 
 use log::error;
-use meilisearch_types::heed::types::{SerdeBincode, Str};
+use meilisearch_types::heed::types::Str;
 use meilisearch_types::heed::{Database, Env, EnvOpenOptions, RoTxn, RwTxn};
 use meilisearch_types::milli::update::IndexerConfig;
 use meilisearch_types::milli::Index;
 use uuid::Uuid;
 
 use self::IndexStatus::{Available, BeingDeleted};
+use crate::uuid_codec::UuidCodec;
 use crate::{Error, Result};
 
 const INDEX_MAPPING: &str = "index-mapping";
@@ -28,9 +29,8 @@ pub struct IndexMapper {
     /// Keep track of the opened indexes. Used mainly by the index resolver.
     index_map: Arc<RwLock<HashMap<Uuid, IndexStatus>>>,
 
-    // TODO create a UUID Codec that uses the 16 bytes representation
     /// Map an index name with an index uuid currently available on disk.
-    pub(crate) index_mapping: Database<Str, SerdeBincode<Uuid>>,
+    pub(crate) index_mapping: Database<Str, UuidCodec>,
 
     /// Path to the folder where the LMDB environments of each index are.
     base_path: PathBuf,

index-scheduler/src/lib.rs

@@ -25,6 +25,7 @@ mod index_mapper;
 #[cfg(test)]
 mod insta_snapshot;
 mod utils;
+mod uuid_codec;
 
 pub type Result<T> = std::result::Result<T, Error>;
 pub type TaskId = u32;

index-scheduler/src/uuid_codec.rs

@@ -0,0 +1,24 @@
+use std::borrow::Cow;
+use std::convert::TryInto;
+
+use meilisearch_types::heed::{BytesDecode, BytesEncode};
+use uuid::Uuid;
+
+/// A heed codec for value of struct Uuid.
+pub struct UuidCodec;
+
+impl<'a> BytesDecode<'a> for UuidCodec {
+    type DItem = Uuid;
+
+    fn bytes_decode(bytes: &'a [u8]) -> Option<Self::DItem> {
+        bytes.try_into().ok().map(Uuid::from_bytes)
+    }
+}
+
+impl BytesEncode<'_> for UuidCodec {
+    type EItem = Uuid;
+
+    fn bytes_encode(item: &Self::EItem) -> Option<Cow<[u8]>> {
+        Some(Cow::Borrowed(item.as_bytes()))
+    }
+}