Merge branch 'main' into indexer-edition-2024

crates/milli/src/fields_ids_map/global.rs

@@ -0,0 +1,108 @@
+use std::collections::BTreeMap;
+use std::sync::RwLock;
+
+use super::MutFieldIdMapper;
+use crate::documents::FieldIdMapper;
+use crate::{FieldId, FieldsIdsMap};
+
+/// A fields ids map that can be globally updated to add fields
+#[derive(Debug, Clone)]
+pub struct GlobalFieldsIdsMap<'indexing> {
+    global: &'indexing RwLock<FieldsIdsMap>,
+    local: LocalFieldsIdsMap,
+}
+
+#[derive(Debug, Clone)]
+pub struct LocalFieldsIdsMap {
+    names_ids: BTreeMap<String, FieldId>,
+    ids_names: BTreeMap<FieldId, String>,
+}
+
+impl FieldIdMapper for LocalFieldsIdsMap {
+    fn id(&self, name: &str) -> Option<FieldId> {
+        self.id(name)
+    }
+
+    fn name(&self, id: FieldId) -> Option<&str> {
+        self.name(id)
+    }
+}
+
+impl LocalFieldsIdsMap {
+    fn new(global: &RwLock<FieldsIdsMap>) -> Self {
+        let global = global.read().unwrap();
+        Self { names_ids: global.names_ids.clone(), ids_names: global.ids_names.clone() }
+    }
+
+    fn insert(&mut self, name: &str, field_id: FieldId) {
+        self.names_ids.insert(name.to_owned(), field_id);
+        self.ids_names.insert(field_id, name.to_owned());
+    }
+
+    fn name(&self, id: FieldId) -> Option<&str> {
+        self.ids_names.get(&id).map(String::as_str)
+    }
+
+    fn id(&self, name: &str) -> Option<FieldId> {
+        self.names_ids.get(name).copied()
+    }
+}
+
+impl<'indexing> GlobalFieldsIdsMap<'indexing> {
+    pub fn new(global: &'indexing RwLock<FieldsIdsMap>) -> Self {
+        Self { local: LocalFieldsIdsMap::new(global), global }
+    }
+
+    /// Returns the field id related to a field name, it will create a new field id if the
+    /// name is not already known. Returns `None` if the maximum field id as been reached.
+    pub fn id_or_insert(&mut self, name: &str) -> Option<FieldId> {
+        if let Some(field_id) = self.local.id(name) {
+            return Some(field_id);
+        }
+
+        {
+            // optimistically lookup the global map
+            let global = self.global.read().unwrap();
+
+            if let Some(field_id) = global.id(name) {
+                self.local.insert(name, field_id);
+                return Some(field_id);
+            }
+        }
+
+        {
+            let mut global = self.global.write().unwrap();
+
+            if let Some(field_id) = global.id(name) {
+                self.local.insert(name, field_id);
+                return Some(field_id);
+            }
+
+            let field_id = global.insert(name)?;
+            self.local.insert(name, field_id);
+            Some(field_id)
+        }
+    }
+
+    /// Get the name of a field based on its id.
+    pub fn name(&mut self, id: FieldId) -> Option<&str> {
+        if self.local.name(id).is_none() {
+            let global = self.global.read().unwrap();
+
+            let name = global.name(id)?;
+            self.local.insert(name, id);
+        }
+
+        self.local.name(id)
+    }
+
+    pub fn local_map(&self) -> &LocalFieldsIdsMap {
+        &self.local
+    }
+}
+
+impl<'indexing> MutFieldIdMapper for GlobalFieldsIdsMap<'indexing> {
+    fn insert(&mut self, name: &str) -> Option<FieldId> {
+        self.id_or_insert(name)
+    }
+}