From 37578ed74f526014a04d57fef878921310553de7 Mon Sep 17 00:00:00 2001
From: Quentin de Quelen <quentin@dequelen.me>
Date: Tue, 12 Feb 2019 17:20:47 +0100
Subject: [PATCH] feat: store config into database

---
 src/database/config.rs | 29 +++++++++++++++++++++++++++++
 src/database/mod.rs    | 30 ++++++++++++++++++++++++++++++
 src/database/view.rs   |  7 +++++--
 3 files changed, 64 insertions(+), 2 deletions(-)
 create mode 100644 src/database/config.rs

diff --git a/src/database/config.rs b/src/database/config.rs
new file mode 100644
index 000000000..2150566a8
--- /dev/null
+++ b/src/database/config.rs
@@ -0,0 +1,29 @@
+use std::collections::{HashSet, HashMap};
+
+use serde_derive::{Serialize, Deserialize};
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub enum RankingOrdering {
+    Asc,
+    Dsc
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct Config {
+    stop_words: Option<HashSet<String>>,
+    ranking_order: Option<Vec<String>>,
+    distinct_field: Option<String>,
+    ranking_rules: Option<HashMap<String, RankingOrdering>>,
+}
+
+
+impl Config {
+    pub(crate) fn default() -> Config {
+        Config {
+            stop_words: None,
+            ranking_order: None,
+            distinct_field: None,
+            ranking_rules: None,
+        }
+    }
+}
diff --git a/src/database/mod.rs b/src/database/mod.rs
index 5d526dcd7..8a032080e 100644
--- a/src/database/mod.rs
+++ b/src/database/mod.rs
@@ -23,6 +23,7 @@ use crate::DocumentId;
 
 use self::update::{ReadIndexEvent, ReadRankedMapEvent};
 
+pub use self::config::Config;
 pub use self::document_key::{DocumentKey, DocumentKeyAttr};
 pub use self::view::{DatabaseView, DocumentIter};
 pub use self::update::Update;
@@ -31,12 +32,15 @@ pub use self::schema::Schema;
 pub use self::index::Index;
 pub use self::number::{Number, ParseNumberError};
 
+
 pub type RankedMap = HashMap<(DocumentId, SchemaAttr), Number>;
 
 const DATA_INDEX:      &[u8] = b"data-index";
 const DATA_RANKED_MAP: &[u8] = b"data-ranked-map";
 const DATA_SCHEMA:     &[u8] = b"data-schema";
+const CONFIG:          &[u8] = b"config";
 
+pub mod config;
 pub mod schema;
 pub(crate) mod index;
 mod number;
@@ -104,6 +108,15 @@ where D: Deref<Target=DB>,
     }
 }
 
+fn retrieve_config<D>(snapshot: &Snapshot<D>) -> Result<Config, Box<Error>>
+where D: Deref<Target=DB>,
+{
+    match snapshot.get(CONFIG)? {
+        Some(vector) => Ok(bincode::deserialize(&*vector)?),
+        None => Ok(Config::default()),
+    }
+}
+
 fn merge_indexes(existing: Option<&[u8]>, operands: &mut MergeOperands) -> Vec<u8> {
     use self::update::ReadIndexEvent::{self, *};
     use self::update::WriteIndexEvent;
@@ -265,6 +278,17 @@ impl DatabaseIndex {
     fn view(&self) -> Arc<DatabaseView<Arc<DB>>> {
         self.view.load()
     }
+
+    fn update_config(&self, config: Config) -> Result<Arc<DatabaseView<Arc<DB>>>, Box<Error>>{
+        let data = bincode::serialize(&config)?;
+        self.db.put(CONFIG, &data)?;
+
+        let snapshot = Snapshot::new(self.db.clone());
+        let view = Arc::new(DatabaseView::new(snapshot)?);
+        self.view.set(view.clone());
+
+        Ok(view)
+    }
 }
 
 impl Drop for DatabaseIndex {
@@ -369,6 +393,12 @@ impl Database {
         Ok(index_guard.val().view())
     }
 
+    pub fn update_config(&self, index: &str, config: Config) -> Result<Arc<DatabaseView<Arc<DB>>>, Box<Error>>{
+        let index_guard = self.indexes.get(index).ok_or("Index not found")?;
+
+        Ok(index_guard.val().update_config(config)?)
+    }
+
 }
 
 #[cfg(test)]
diff --git a/src/database/view.rs b/src/database/view.rs
index 74e4ef002..3cee6db4e 100644
--- a/src/database/view.rs
+++ b/src/database/view.rs
@@ -7,13 +7,14 @@ use rocksdb::rocksdb_options::{ReadOptions, EnvOptions, ColumnFamilyOptions};
 use rocksdb::rocksdb::{DB, DBVector, Snapshot, SeekKey, SstFileWriter};
 use serde::de::DeserializeOwned;
 
-use crate::database::{retrieve_data_schema, retrieve_data_index, retrieve_data_ranked_map};
+use crate::database::{retrieve_data_schema, retrieve_data_index, retrieve_data_ranked_map, retrieve_config};
 use crate::database::serde::deserializer::Deserializer;
 use crate::database::{DocumentKey, DocumentKeyAttr};
 use crate::rank::{QueryBuilder, FilterFunc};
 use crate::database::schema::Schema;
 use crate::database::index::Index;
 use crate::database::RankedMap;
+use crate::database::Config;
 use crate::DocumentId;
 
 pub struct DatabaseView<D>
@@ -23,6 +24,7 @@ where D: Deref<Target=DB>
     index: Index,
     ranked_map: RankedMap,
     schema: Schema,
+    config: Config,
 }
 
 impl<D> DatabaseView<D>
@@ -32,7 +34,8 @@ where D: Deref<Target=DB>
         let schema = retrieve_data_schema(&snapshot)?;
         let index = retrieve_data_index(&snapshot)?;
         let ranked_map = retrieve_data_ranked_map(&snapshot)?;
-        Ok(DatabaseView { snapshot, index, ranked_map, schema })
+        let config = retrieve_config(&snapshot)?;
+        Ok(DatabaseView { snapshot, index, ranked_map, schema, config })
     }
 
     pub fn schema(&self) -> &Schema {