perf(graph): eliminate heavy allocations by substituting KnowledgeGraph clones with BorrowedGraph for json serialization

server/src/handlers_v2/graph.rs

@@ -7,6 +7,21 @@ use serde_json::Value;
 use std::collections::HashSet;
 use std::sync::Arc;
 
+#[derive(serde::Serialize)]
+struct BorrowedGraph<'a> {
+    entities: std::collections::HashMap<&'a String, &'a crate::models::Entity>,
+    relations: Vec<&'a crate::models::Relation>,
+}
+
+impl<'a> Default for BorrowedGraph<'a> {
+    fn default() -> Self {
+        Self {
+            entities: std::collections::HashMap::new(),
+            relations: Vec::new(),
+        }
+    }
+}
+
 pub struct QueryGraphPathHandler;
 
 #[async_trait]
@@ -267,15 +282,15 @@ impl McpTool for ReadGraphHandler {
         let req: ReadGraphTool = serde_json::from_value(args).map_err(|e| e.to_string())?;
         let data = state.read_graph(|full| {
             if let Some(ns) = req.namespace {
-                let mut filtered = KnowledgeGraph::default();
+                let mut filtered = BorrowedGraph::default();
                 for (k, v) in &full.entities {
                     if v.namespace == ns {
-                        filtered.entities.insert(k.clone(), v.clone());
+                        filtered.entities.insert(k, v);
                     }
                 }
                 for r in &full.relations {
                     if r.namespace == ns {
-                        filtered.relations.push(r.clone());
+                        filtered.relations.push(r);
                     }
                 }
                 serde_json::to_string(&filtered).unwrap_or_default()
@@ -308,18 +323,18 @@ impl McpTool for SearchNodesHandler {
             vec![]
         };
 
-        let mut result = KnowledgeGraph::default();
-        state.read_graph(|full| {
-            for (id, doc_type, _, _, _) in matches {
+        let data = state.read_graph(|full| {
+            let mut result = BorrowedGraph::default();
+            for (id, doc_type, _, _, _) in &matches {
                 if doc_type == "entity"
-                    && let Some(e) = full.entities.get(&id)
+                    && let Some(e) = full.entities.get(id)
                 {
-                    result.entities.insert(id, e.clone());
+                    result.entities.insert(id, e);
                 }
             }
+            serde_json::to_string(&result).unwrap_or_default()
         });
-        let data = serde_json::to_string(&result).unwrap_or_default();
-        Ok(data.to_string())
+        Ok(data)
     }
 }
 
@@ -337,28 +352,27 @@ impl McpTool for OpenNodesHandler {
 
     async fn execute(&self, args: Value, state: Arc<MemoryState>) -> Result<String, String> {
         let req: OpenNodesTool = serde_json::from_value(args).map_err(|e| e.to_string())?;
-        let result = state.read_graph(|full| {
+        let data = state.read_graph(|full| {
             let targets: HashSet<&str> = req.names.iter().map(|s| s.as_str()).collect();
-            let mut result = KnowledgeGraph::default();
+            let mut result = BorrowedGraph::default();
             let mut connected: HashSet<&str> = HashSet::new();
             for r in &full.relations {
                 if targets.contains(r.from.as_str()) {
                     connected.insert(r.to.as_str());
-                    result.relations.push(r.clone());
+                    result.relations.push(r);
                 } else if targets.contains(r.to.as_str()) {
                     connected.insert(r.from.as_str());
-                    result.relations.push(r.clone());
+                    result.relations.push(r);
                 }
             }
             for (name, e) in &full.entities {
                 if targets.contains(name.as_str()) || connected.contains(name.as_str()) {
-                    result.entities.insert(name.clone(), e.clone());
+                    result.entities.insert(name, e);
                 }
             }
-            result
+            serde_json::to_string(&result).unwrap_or_default()
         });
-        let data = serde_json::to_string(&result).unwrap_or_default();
-        Ok(data.to_string())
+        Ok(data)
     }
 }
 

temp_setup.lua

@@ -0,0 +1,6 @@
+local buf = vim.fn.bufnr('server/src/handlers_v2/graph.rs')
+if buf == -1 then
+    vim.cmd('e server/src/handlers_v2/graph.rs')
+    buf = vim.api.nvim_get_current_buf()
+end
+return vim.api.nvim_buf_get_name(buf)