From 2ee3927bd4bb91c268ca3b16ef7b9d9ee11561de Mon Sep 17 00:00:00 2001
From: QP Hou <dave2008713@gmail.com>
Date: Sat, 19 Mar 2022 12:22:12 -0700
Subject: [PATCH] avoid hashmap clone in schema api calls (#158)

---
 roapi-http/src/api/mod.rs    | 48 +++++++++++++++++++++++++++++++-----
 roapi-http/src/api/schema.rs | 17 +++----------
 2 files changed, 45 insertions(+), 20 deletions(-)

diff --git a/roapi-http/src/api/mod.rs b/roapi-http/src/api/mod.rs
index 2383de1..920eec5 100644
--- a/roapi-http/src/api/mod.rs
+++ b/roapi-http/src/api/mod.rs
@@ -49,16 +49,21 @@ pub trait HandlerCtx: Send + Sync + 'static {
     fn read_only_mode() -> bool;
 
     async fn load_table(&self, table: &TableSource) -> Result<(), ColumnQError>;
-    // FIXME: avoid clone
-    async fn schema_map(&self) -> HashMap<String, arrow::datatypes::SchemaRef>;
+
+    async fn schemas_json_bytes(&self) -> Result<Vec<u8>, ApiErrResp>;
+
+    async fn table_schema_json_bytes(&self, table_name: &str) -> Result<Vec<u8>, ApiErrResp>;
+
     async fn query_graphql(
         &self,
         query: &str,
     ) -> Result<Vec<arrow::record_batch::RecordBatch>, QueryError>;
+
     async fn query_sql(
         &self,
         query: &str,
     ) -> Result<Vec<arrow::record_batch::RecordBatch>, QueryError>;
+
     async fn query_rest_table(
         &self,
         table_name: &str,
@@ -81,8 +86,23 @@ impl HandlerCtx for RawHandlerContext {
     }
 
     #[inline]
-    async fn schema_map(&self) -> HashMap<String, arrow::datatypes::SchemaRef> {
-        self.cq.schema_map().clone()
+    async fn schemas_json_bytes(&self) -> Result<Vec<u8>, ApiErrResp> {
+        serde_json::to_vec(self.cq.schema_map())
+            .map_err(columnq::error::ColumnQError::from)
+            .map_err(ApiErrResp::json_serialization)
+    }
+
+    #[inline]
+    async fn table_schema_json_bytes(&self, table_name: &str) -> Result<Vec<u8>, ApiErrResp> {
+        serde_json::to_vec(
+            self.cq
+                .schema_map()
+                .get(table_name)
+                .ok_or_else(|| ApiErrResp::not_found("invalid table name"))?
+                .as_ref(),
+        )
+        .map_err(columnq::error::ColumnQError::from)
+        .map_err(ApiErrResp::json_serialization)
     }
 
     #[inline]
@@ -125,9 +145,25 @@ impl HandlerCtx for ConcurrentHandlerContext {
     }
 
     #[inline]
-    async fn schema_map(&self) -> HashMap<String, arrow::datatypes::SchemaRef> {
+    async fn schemas_json_bytes(&self) -> Result<Vec<u8>, ApiErrResp> {
         let ctx = self.read().await;
-        ctx.cq.schema_map().clone()
+        serde_json::to_vec(ctx.cq.schema_map())
+            .map_err(columnq::error::ColumnQError::from)
+            .map_err(ApiErrResp::json_serialization)
+    }
+
+    #[inline]
+    async fn table_schema_json_bytes(&self, table_name: &str) -> Result<Vec<u8>, ApiErrResp> {
+        let ctx = self.read().await;
+        serde_json::to_vec(
+            ctx.cq
+                .schema_map()
+                .get(table_name)
+                .ok_or_else(|| ApiErrResp::not_found("invalid table name"))?
+                .as_ref(),
+        )
+        .map_err(columnq::error::ColumnQError::from)
+        .map_err(ApiErrResp::json_serialization)
     }
 
     #[inline]
diff --git a/roapi-http/src/api/schema.rs b/roapi-http/src/api/schema.rs
index d7ac91d..a2c0e66 100644
--- a/roapi-http/src/api/schema.rs
+++ b/roapi-http/src/api/schema.rs
@@ -10,26 +10,15 @@ pub async fn schema<H: HandlerCtx>(
     state: extract::Extension<Arc<H>>,
 ) -> Result<impl IntoResponse, ApiErrResp> {
     let ctx = state.0;
-    let schema = ctx.schema_map().await;
-    let payload = serde_json::to_vec(&schema)
-        .map_err(columnq::error::ColumnQError::from)
-        .map_err(ApiErrResp::json_serialization)?;
+    let payload = ctx.schemas_json_bytes().await?;
     Ok(bytes_to_json_resp(payload))
 }
 
 pub async fn get_by_table_name<H: HandlerCtx>(
     state: extract::Extension<Arc<H>>,
-    extract::Path(table_name): extract::Path<String>,
+    extract::Path(table_name): extract::Path<&str>,
 ) -> Result<impl IntoResponse, ApiErrResp> {
     let ctx = state.0;
-    let payload = serde_json::to_vec(
-        ctx.schema_map()
-            .await
-            .get(&table_name)
-            .ok_or_else(|| ApiErrResp::not_found("invalid table name"))?
-            .as_ref(),
-    )
-    .map_err(columnq::error::ColumnQError::from)
-    .map_err(ApiErrResp::json_serialization)?;
+    let payload = ctx.table_schema_json_bytes(table_name).await?;
     Ok(bytes_to_json_resp(payload))
 }