feat(query): add catalog stats api (#17602)

* feat(query): add catalog stats api

* z

* z

* z

* z

Author: everpcpc

src/query/service/src/servers/http/v1/catalog/mod.rs

@@ -18,10 +18,12 @@ pub mod list_database_tables;
 pub mod list_databases;
 pub mod search_databases;
 pub mod search_tables;
+pub mod stats;
 
 pub use get_database_table::get_database_table_handler;
 pub use list_database_table_fields::list_database_table_fields_handler;
 pub use list_database_tables::list_database_tables_handler;
 pub use list_databases::list_databases_handler;
 pub use search_databases::search_databases_handler;
 pub use search_tables::search_tables_handler;
+pub use stats::catalog_stats_handler;

src/query/service/src/servers/http/v1/catalog/stats.rs

@@ -0,0 +1,73 @@
+// Copyright 2021 Datafuse Labs
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use databend_common_catalog::catalog::CatalogManager;
+use databend_common_exception::Result;
+use poem::error::InternalServerError;
+use poem::error::Result as PoemResult;
+use poem::web::Json;
+use poem::IntoResponse;
+use serde::Deserialize;
+use serde::Serialize;
+
+use crate::servers::http::v1::HttpQueryContext;
+
+#[derive(Serialize, Deserialize, Eq, PartialEq, Debug, Default)]
+pub struct CatalogStatsResponse {
+    pub tables: u64,
+    pub databases: u64,
+}
+
+#[async_backtrace::framed]
+async fn handle(ctx: &HttpQueryContext) -> Result<CatalogStatsResponse> {
+    let tenant = ctx.session.get_current_tenant();
+    let visibility_checker = ctx.session.get_visibility_checker(false).await?;
+
+    let catalog = CatalogManager::instance().get_default_catalog(Default::default())?;
+
+    let mut tables: u64 = 0;
+    let mut databases: u64 = 0;
+
+    for db in catalog.list_databases(&tenant).await? {
+        if !visibility_checker.check_database_visibility(
+            catalog.name().as_str(),
+            db.name(),
+            db.get_db_info().database_id.db_id,
+        ) {
+            continue;
+        }
+        databases += 1;
+        for table in db.list_tables().await? {
+            if !visibility_checker.check_table_visibility(
+                catalog.name().as_str(),
+                db.name(),
+                table.name(),
+                db.get_db_info().database_id.db_id,
+                table.get_table_info().ident.table_id,
+            ) {
+                continue;
+            }
+            tables += 1;
+        }
+    }
+
+    Ok(CatalogStatsResponse { tables, databases })
+}
+
+#[poem::handler]
+#[async_backtrace::framed]
+pub async fn catalog_stats_handler(ctx: &HttpQueryContext) -> PoemResult<impl IntoResponse> {
+    let resp = handle(ctx).await.map_err(InternalServerError)?;
+    Ok(Json(resp))
+}

src/query/service/src/servers/http/v1/http_query_handlers.rs

@@ -50,6 +50,7 @@ use crate::servers::http::error::QueryError;
 use crate::servers::http::middleware::EndpointKind;
 use crate::servers::http::middleware::HTTPSessionMiddleware;
 use crate::servers::http::middleware::MetricsMiddleware;
+use crate::servers::http::v1::catalog::catalog_stats_handler;
 use crate::servers::http::v1::catalog::get_database_table_handler;
 use crate::servers::http::v1::catalog::list_database_table_fields_handler;
 use crate::servers::http::v1::catalog::list_database_tables_handler;
@@ -515,6 +516,11 @@ pub fn query_route() -> Route {
             post(search_databases_handler),
             EndpointKind::Catalog,
         ),
+        (
+            "/catalog/stats",
+            get(catalog_stats_handler),
+            EndpointKind::Catalog,
+        ),
         (
             "/users",
             get(list_users_handler).post(create_user_handler),

src/query/service/tests/it/servers/http/http_query_handlers.rs

@@ -870,6 +870,13 @@ async fn test_catalog_apis() -> Result<()> {
     assert_eq!(body.fields.len(), 1);
     assert_eq!(body.fields[0].name, "a");
 
+    let response = get_uri(&ep, "/v1/catalog/stats").await;
+    assert_eq!(response.status(), StatusCode::OK);
+    let body = response.into_body().into_string().await.unwrap();
+    let body: catalog::stats::CatalogStatsResponse = serde_json::from_str(&body).unwrap();
+    assert_eq!(body.tables, 1);
+    assert_eq!(body.databases, 3);
+
     Ok(())
 }