feat: Introduce index events to update the WordIndex

meilidb-data/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2018"
 
 [dependencies]
 bincode = "1.1.2"
+byteorder = "1.3.1"
 hashbrown = { version = "0.1.8", features = ["serde"] }
 linked-hash-map = { version = "0.5.2", features = ["serde_impl"] }
 meilidb-core = { path = "../meilidb-core", version = "0.1.0" }

meilidb-data/src/index_event.rs

@@ -0,0 +1,45 @@
+use std::error::Error;
+
+use byteorder::{ReadBytesExt, WriteBytesExt};
+
+use meilidb_core::{Index as WordIndex};
+use meilidb_core::data::DocIds;
+use meilidb_core::write_to_bytes::WriteToBytes;
+use meilidb_core::shared_data_cursor::{SharedDataCursor, FromSharedDataCursor};
+
+enum NewIndexEvent<'a> {
+    RemovedDocuments(&'a DocIds),
+    UpdatedDocuments(&'a WordIndex),
+}
+
+impl<'a> WriteToBytes for NewIndexEvent<'a> {
+    fn write_to_bytes(&self, bytes: &mut Vec<u8>) {
+        match self {
+            NewIndexEvent::RemovedDocuments(doc_ids) => {
+                let _ = bytes.write_u8(0);
+                doc_ids.write_to_bytes(bytes);
+            },
+            NewIndexEvent::UpdatedDocuments(index) => {
+                let _ = bytes.write_u8(1);
+                index.write_to_bytes(bytes);
+            }
+        }
+    }
+}
+
+enum IndexEvent {
+    RemovedDocuments(DocIds),
+    UpdatedDocuments(WordIndex),
+}
+
+impl FromSharedDataCursor for IndexEvent {
+    type Error = Box<Error>;
+
+    fn from_shared_data_cursor(cursor: &mut SharedDataCursor) -> Result<Self, Self::Error> {
+        match cursor.read_u8()? {
+            0 => DocIds::from_shared_data_cursor(cursor).map(IndexEvent::RemovedDocuments),
+            1 => WordIndex::from_shared_data_cursor(cursor).map(IndexEvent::UpdatedDocuments),
+            _ => Err("invalid index event type".into()),
+        }
+    }
+}

meilidb-data/src/lib.rs

@@ -1,4 +1,5 @@
 mod database;
+mod index_event;
 mod indexer;
 mod number;
 mod ranked_map;
@@ -8,4 +9,3 @@ pub use self::database::{Database, Index};
 pub use self::number::Number;
 pub use self::ranked_map::RankedMap;
 pub use self::schema::{Schema, SchemaAttr};
-pub use self::indexer::Indexer;