feat: add typed index custom settings for common uses

meilidb-data/src/database/index/custom_settings_index.rs

@@ -1,4 +1,25 @@
+use serde::de::DeserializeOwned;
+use serde::{Serialize, Deserialize};
+use std::collections::{HashMap, HashSet};
 use std::ops::Deref;
+use super::Error;
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum RankingOrdering {
+    Asc,
+    Dsc
+}
+
+pub type StopWords = HashSet<String>;
+pub type RankingOrder = Vec<String>;
+pub type DistinctField = String;
+pub type RankingRules = HashMap<String, RankingOrdering>;
+
+const STOP_WORDS_KEY:       &str = "stop-words";
+const RANKING_ORDER_KEY:    &str = "ranking-order";
+const DISTINCT_FIELD_KEY:   &str = "distinct-field";
+const RANKING_RULES_KEY:    &str = "ranking-rules";
 
 #[derive(Clone)]
 pub struct CustomSettingsIndex(pub(crate) crate::CfTree);
@@ -10,3 +31,59 @@ impl Deref for CustomSettingsIndex {
         &self.0
     }
 }
+
+impl CustomSettingsIndex {
+    fn get<K, T>(&self, key: K) -> Result<Option<T>, Error>
+    where K: AsRef<[u8]>,
+          T: DeserializeOwned,
+    {
+        let setting = self.0.get(key)?;
+        let raw = match setting {
+            Some(raw) => raw,
+            None => return Ok(None)
+        };
+
+        Ok(Some(bincode::deserialize(&raw)?))
+    }
+
+    fn set<K, T>(&self, key: K, data: &T) -> Result<(), Error>
+    where K: AsRef<[u8]>,
+          T: Serialize,
+    {
+        let raw = bincode::serialize(data)?;
+        self.0.insert(key, &raw)?;
+        Ok(())
+    }
+
+    pub fn get_stop_words(&self) -> Result<Option<StopWords>, Error> {
+        self.get(STOP_WORDS_KEY)
+    }
+
+    pub fn get_ranking_order(&self) -> Result<Option<RankingOrder>, Error> {
+        self.get(RANKING_ORDER_KEY)
+    }
+
+    pub fn get_distinct_field(&self) -> Result<Option<DistinctField>, Error> {
+        self.get(DISTINCT_FIELD_KEY)
+    }
+
+    pub fn get_ranking_rules(&self) -> Result<Option<RankingRules>, Error> {
+        self.get(RANKING_RULES_KEY)
+    }
+
+    pub fn set_stop_words(&self, value: &StopWords) -> Result<(), Error> {
+        self.set(STOP_WORDS_KEY, value)
+    }
+
+    pub fn set_ranking_order(&self, value: &RankingOrder) -> Result<(), Error> {
+        self.set(RANKING_ORDER_KEY, value)
+    }
+
+    pub fn set_distinct_field(&self, value: &DistinctField) -> Result<(), Error> {
+        self.set(DISTINCT_FIELD_KEY, value)
+    }
+
+    pub fn set_ranking_rules(&self, value: &RankingRules) -> Result<(), Error> {
+        self.set(RANKING_RULES_KEY, value)
+    }
+}

meilidb-data/src/database/index/mod.rs

@@ -17,7 +17,7 @@ use crate::CfTree;
 use crate::ranked_map::RankedMap;
 use crate::serde::{Deserializer, DeserializerError};
 
-pub use self::custom_settings_index::CustomSettingsIndex;
+pub use self::custom_settings_index::{CustomSettingsIndex, RankingOrdering, StopWords, RankingOrder, DistinctField, RankingRules};
 pub use self::common_index::CommonIndex;
 use self::docs_words_index::DocsWordsIndex;
 use self::documents_index::DocumentsIndex;

meilidb-data/src/database/mod.rs

@@ -12,7 +12,7 @@ mod update;
 use crate::CfTree;
 
 pub use self::error::Error;
-pub use self::index::{Index, CustomSettingsIndex, CommonIndex};
+pub use self::index::{Index, CustomSettingsIndex, CommonIndex, RankingOrdering, StopWords, RankingOrder, DistinctField, RankingRules};
 
 pub use self::update::DocumentsAddition;
 pub use self::update::DocumentsDeletion;

meilidb-data/src/lib.rs

@@ -7,7 +7,7 @@ mod ranked_map;
 mod serde;
 
 pub use self::cf_tree::{CfTree, CfIter};
-pub use self::database::{Database, Index, CustomSettingsIndex};
+pub use self::database::{Database, Index, CustomSettingsIndex, RankingOrdering, StopWords, RankingOrder, DistinctField, RankingRules};
 pub use self::number::Number;
 pub use self::ranked_map::RankedMap;
 pub use self::serde::{compute_document_id, extract_document_id, value_to_string};