From ab6dbe654f32a153692e9d304d1cd179c761412f Mon Sep 17 00:00:00 2001
From: Pavel Emelyanov <xemul@scylladb.com>
Date: Fri, 28 Jul 2023 15:54:13 +0300
Subject: [PATCH] schema_tables: Extract query_processor from system_keyspace
 for querying

The schema_tables() column-mapping code runs queries over system. table,
but it needs LOCAL_ONE CL and cherry-pick on caching, so regular
system_keyspace::execute_cql() won't work here.

However, since schema_tables is somewhat part of system_keyspace, it's
natural to let the former fetch private query_processor& from the latter

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
---
 db/schema_tables.cc   |  6 +++---
 db/system_keyspace.hh | 11 +++++++++++
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/db/schema_tables.cc b/db/schema_tables.cc
index ddf5a071e4..382e638458 100644
--- a/db/schema_tables.cc
+++ b/db/schema_tables.cc
@@ -3705,7 +3705,7 @@ static auto GET_COLUMN_MAPPING_QUERY = format("SELECT column_name, clustering_or
     db::schema_tables::SCYLLA_TABLE_SCHEMA_HISTORY);
 
 future<column_mapping> get_column_mapping(db::system_keyspace& sys_ks, ::table_id table_id, table_schema_version version) {
-    shared_ptr<cql3::untyped_result_set> results = co_await qctx->qp().execute_internal(
+    shared_ptr<cql3::untyped_result_set> results = co_await sys_ks._qp.execute_internal(
         GET_COLUMN_MAPPING_QUERY,
         db::consistency_level::LOCAL_ONE,
         {table_id.uuid(), version.uuid()},
@@ -3746,7 +3746,7 @@ future<column_mapping> get_column_mapping(db::system_keyspace& sys_ks, ::table_i
 }
 
 future<bool> column_mapping_exists(db::system_keyspace& sys_ks, table_id table_id, table_schema_version version) {
-    shared_ptr<cql3::untyped_result_set> results = co_await qctx->qp().execute_internal(
+    shared_ptr<cql3::untyped_result_set> results = co_await sys_ks._qp.execute_internal(
         GET_COLUMN_MAPPING_QUERY,
         db::consistency_level::LOCAL_ONE,
         {table_id.uuid(), version.uuid()},
@@ -3759,7 +3759,7 @@ future<> drop_column_mapping(db::system_keyspace& sys_ks, table_id table_id, tab
     const static sstring DEL_COLUMN_MAPPING_QUERY =
         format("DELETE FROM system.{} WHERE cf_id = ? and schema_version = ?",
             db::schema_tables::SCYLLA_TABLE_SCHEMA_HISTORY);
-    co_await qctx->qp().execute_internal(
+    co_await sys_ks._qp.execute_internal(
         DEL_COLUMN_MAPPING_QUERY,
         db::consistency_level::LOCAL_ONE,
         {table_id.uuid(), version.uuid()},
diff --git a/db/system_keyspace.hh b/db/system_keyspace.hh
index 72928df805..f5bb61e901 100644
--- a/db/system_keyspace.hh
+++ b/db/system_keyspace.hh
@@ -78,6 +78,13 @@ namespace db {
 
 sstring system_keyspace_name();
 
+class system_keyspace;
+namespace schema_tables {
+future<column_mapping> get_column_mapping(db::system_keyspace& sys_ks, ::table_id table_id, table_schema_version version);
+future<bool> column_mapping_exists(db::system_keyspace& sys_ks, table_id table_id, table_schema_version version);
+future<> drop_column_mapping(db::system_keyspace& sys_ks, table_id table_id, table_schema_version version);
+}
+
 class config;
 struct local_cache;
 
@@ -509,6 +516,10 @@ public:
     future<::shared_ptr<cql3::untyped_result_set>> execute_cql(sstring req, Args&&... args) {
         return execute_cql(req, { data_value(std::forward<Args>(args))... });
     }
+
+    friend future<column_mapping> db::schema_tables::get_column_mapping(db::system_keyspace& sys_ks, ::table_id table_id, table_schema_version version);
+    friend future<bool> db::schema_tables::column_mapping_exists(db::system_keyspace& sys_ks, table_id table_id, table_schema_version version);
+    friend future<> db::schema_tables::drop_column_mapping(db::system_keyspace& sys_ks, table_id table_id, table_schema_version version);
 }; // class system_keyspace
 
 } // namespace db