treewide: Add new describe overloads to implementations of data_dictionary::keyspace_element

We're removing `data_dictionary::keyspace_element`.
Before we can do that, we need to substitute the existing
methods used for describing keyspace elements with their
new versions returning `cql3::description`.
That's what happens in this commit.

cql3/functions/aggregate_fcts.cc

@@ -355,10 +355,12 @@ user_aggregate::user_aggregate(function_name fname, bytes_opt initcond, ::shared
 
 bool user_aggregate::has_finalfunc() const { return _agg.state_to_result_function != nullptr; }
 
-std::ostream& user_aggregate::describe(std::ostream& os) const {
+description user_aggregate::describe() const {
     auto ks = cql3::util::maybe_quote(name().keyspace);
     auto na = cql3::util::maybe_quote(name().name);
 
+    std::ostringstream os;
+
     os << "CREATE AGGREGATE " << ks << "." << na << "(";
     auto a = arg_types();
     for (size_t i = 0; i < a.size(); i++) {
@@ -382,6 +384,17 @@ std::ostream& user_aggregate::describe(std::ostream& os) const {
     }
     os << ";";
 
+    return description {
+        .keyspace = name().keyspace,
+        .type = "aggregate",
+        .name = name().name,
+        .create_statement = std::move(os).str()
+    };
+}
+
+std::ostream& user_aggregate::describe(std::ostream& os) const {
+    auto desc = describe();
+    os << *desc.create_statement;
     return os;
 }
 

cql3/functions/user_aggregate.hh

@@ -9,6 +9,7 @@
 #pragma once
 
 #include "scalar_function.hh"
+#include "cql3/description.hh"
 #include "data_dictionary/keyspace_element.hh"
 #include "cql3/functions/function_name.hh"
 #include "db/functions/aggregate_function.hh"
@@ -26,6 +27,8 @@ public:
     virtual sstring element_type() const override { return "aggregate"; }
     virtual std::ostream& describe(std::ostream& os) const override;
 
+    description describe() const;
+
     seastar::shared_ptr<scalar_function> sfunc() const {
         return _agg.aggregation_function;
     }

cql3/functions/user_function.cc

@@ -66,10 +66,12 @@ bytes_opt user_function::execute(std::span<const bytes_opt> parameters) {
         });
 }
 
-std::ostream& user_function::describe(std::ostream& os) const {
+description user_function::describe() const {
     auto ks = cql3::util::maybe_quote(name().keyspace);
     auto na = cql3::util::maybe_quote(name().name);
 
+    std::ostringstream os;
+
     os << "CREATE FUNCTION " << ks << "." << na << "(";
     for (size_t i = 0; i < _arg_names.size(); i++) {
         if (i > 0) {
@@ -91,6 +93,17 @@ std::ostream& user_function::describe(std::ostream& os) const {
        << _body << "\n"
        << "$$;";
 
+    return description {
+        .keyspace = name().keyspace,
+        .type = "function",
+        .name = name().name,
+        .create_statement = std::move(os).str()
+    };
+}
+
+std::ostream& user_function::describe(std::ostream& os) const {
+    auto desc = describe();
+    os << *desc.create_statement;
     return os;
 }
 

cql3/functions/user_function.hh

@@ -11,6 +11,7 @@
 #pragma once
 
 #include "abstract_function.hh"
+#include "cql3/description.hh"
 #include "scalar_function.hh"
 #include "lang/lua.hh"
 #include "lang/wasm.hh"
@@ -65,6 +66,8 @@ public:
     virtual sstring element_name() const override { return name().name; }
     virtual sstring element_type() const override { return "function"; }
     virtual std::ostream& describe(std::ostream& os) const override;
+
+    description describe() const;
 };
 
 }

data_dictionary/data_dictionary.cc

@@ -7,6 +7,7 @@
  */
 
 #include "data_dictionary.hh"
+#include "cql3/description.hh"
 #include "impl.hh"
 #include "user_types_metadata.hh"
 #include "keyspace_metadata.hh"
@@ -351,7 +352,9 @@ no_such_column_family::no_such_column_family(std::string_view ks_name, const tab
 {
 }
 
-std::ostream& keyspace_metadata::describe(replica::database& db, std::ostream& os, bool with_internals) const {
+cql3::description keyspace_metadata::describe(const replica::database& db) const {
+    std::ostringstream os;
+
     os << "CREATE KEYSPACE " << cql3::util::maybe_quote(_name)
        << " WITH replication = {'class': " << cql3::util::single_quote(_strategy_name);
     for (const auto& opt: _strategy_options) {
@@ -373,10 +376,21 @@ std::ostream& keyspace_metadata::describe(replica::database& db, std::ostream& o
     }
     os << ";";
 
+    return cql3::description {
+        .keyspace = name(),
+        .type = "keyspace",
+        .name = name(),
+        .create_statement = std::move(os).str()
+    };
+}
+
+std::ostream& keyspace_metadata::describe(replica::database& db, std::ostream& os, bool with_internals) const {
+    auto desc = describe(db);
+    os << *desc.create_statement;
     return os;
 }
 
-}
+} // namespace data_dictionary
 
 template <>
 struct fmt::formatter<data_dictionary::user_types_metadata> {

data_dictionary/keyspace_metadata.hh

@@ -13,6 +13,7 @@
 #include <iosfwd>
 #include <seastar/core/sstring.hh>
 
+#include "cql3/description.hh"
 #include "schema/schema.hh"
 #include "locator/abstract_replication_strategy.hh"
 #include "data_dictionary/user_types_metadata.hh"
@@ -99,6 +100,8 @@ public:
     virtual sstring element_name() const override { return name(); }
     virtual sstring element_type() const override { return "keyspace"; }
     virtual std::ostream& describe(replica::database& db, std::ostream& os, bool with_internals) const override;
+
+    cql3::description describe(const replica::database& db) const;
 };
 
 }

schema/schema.cc

@@ -8,6 +8,7 @@
 
 #include <seastar/core/on_internal_error.hh>
 #include <map>
+#include "cql3/description.hh"
 #include "db/view/view.hh"
 #include "timestamp.hh"
 #include "utils/assert.hh"
@@ -783,11 +784,11 @@ static std::ostream& column_definition_as_cql_key(std::ostream& os, const column
     return os;
 }
 
-static bool is_global_index(replica::database& db, const table_id& id, const schema& s) {
+static bool is_global_index(const replica::database& db, const table_id& id, const schema& s) {
     return  db.find_column_family(id).get_index_manager().is_global_index(s);
 }
 
-static bool is_index(replica::database& db, const table_id& id, const schema& s) {
+static bool is_index(const replica::database& db, const table_id& id, const schema& s) {
     return  db.find_column_family(id).get_index_manager().is_index(s);
 }
 
@@ -852,7 +853,9 @@ static void describe_index_columns(std::ostream& os, bool is_local, const schema
     os << ")";
 }
 
-std::ostream& schema::describe(replica::database& db, std::ostream& os, bool with_internals) const {
+sstring schema::get_create_statement(const replica::database& db, bool with_internals) const {
+    std::ostringstream os;
+
     os << "CREATE ";
     int n = 0;
 
@@ -865,7 +868,8 @@ std::ostream& schema::describe(replica::database& db, std::ostream& os, bool wit
 
             describe_index_columns(os, is_local, *this, db.find_schema(view_info()->base_id()));  
             os << ";\n";
-            return os;
+
+            return std::move(os).str();
         } else {
             os << "MATERIALIZED VIEW " << cql3::util::maybe_quote(ks_name()) << "." << cql3::util::maybe_quote(cf_name()) << " AS\n";
             os << "    SELECT ";
@@ -970,10 +974,34 @@ std::ostream& schema::describe(replica::database& db, std::ostream& os, bool wit
         }
     }
 
+    return std::move(os).str();
+}
+
+cql3::description schema::describe(const replica::database& db, bool with_internals) const {
+    const sstring type = std::invoke([&] {
+        if (is_view()) {
+            return is_index(db, view_info()->base_id(), *this)
+                    ? "index"
+                    : "view";
+        }
+        return "table";
+    });
+
+    return cql3::description {
+        .keyspace = ks_name(),
+        .type = std::move(type),
+        .name = cf_name(),
+        .create_statement = get_create_statement(db, with_internals)
+    };
+}
+
+std::ostream& schema::describe(replica::database& db, std::ostream& os, bool with_internals) const {
+    auto desc = describe(db, with_internals);
+    os << *desc.create_statement;
     return os;
 }
 
-std::ostream& schema::schema_properties(replica::database& db, std::ostream& os) const {
+std::ostream& schema::schema_properties(const replica::database& db, std::ostream& os) const {
     os << "bloom_filter_fp_chance = " << bloom_filter_fp_chance();
     os << "\n    AND caching = {";
     map_as_cql_param(os, caching_options().to_map());

schema/schema.hh

@@ -8,6 +8,7 @@
 
 #pragma once
 
+#include "cql3/description.hh"
 #include "utils/assert.hh"
 #include <functional>
 #include <optional>
@@ -919,6 +920,9 @@ public:
      * (and `ALTER ADD` if the column has been re-added) to the description.
      */
     virtual std::ostream& describe(replica::database& db, std::ostream& os, bool with_internals) const override;
+
+    cql3::description describe(const replica::database& db, bool with_internals) const;
+
     // Generate ALTER TABLE/MATERIALIZED VIEW statement containing all properties with current values.
     // The method cannot be used on index, as indexes don't support alter statement.
     std::ostream& describe_alter_with_properties(replica::database& db, std::ostream& os) const;
@@ -938,7 +942,9 @@ public:
     }
 private:
     // Print all schema properties in CQL syntax
-    std::ostream& schema_properties(replica::database& db, std::ostream& os) const;
+    std::ostream& schema_properties(const replica::database& db, std::ostream& os) const;
+
+    sstring get_create_statement(const replica::database& db, bool with_internals) const;
 public:
     const v3_columns& v3() const {
         return _v3_columns;

types/types.cc

@@ -9,6 +9,7 @@
 #include <boost/lexical_cast.hpp>
 #include <algorithm>
 #include "cql3/cql3_type.hh"
+#include "cql3/description.hh"
 #include "cql3/lists.hh"
 #include "cql3/maps.hh"
 #include "cql3/sets.hh"
@@ -3234,7 +3235,9 @@ sstring user_type_impl::get_name_as_cql_string() const {
     return cql3::util::maybe_quote(get_name_as_string());
 }
 
-std::ostream& user_type_impl::describe(std::ostream& os) const {
+cql3::description user_type_impl::describe() const {
+    std::ostringstream os;
+
     os << "CREATE TYPE " << cql3::util::maybe_quote(_keyspace) << "." << get_name_as_cql_string() << " (\n";
     for (size_t i = 0; i < _string_field_names.size(); i++) {
         os << "    " << cql3::util::maybe_quote(_string_field_names[i]) << " " << _types[i]->cql3_type_name();
@@ -3245,6 +3248,17 @@ std::ostream& user_type_impl::describe(std::ostream& os) const {
     }
     os << ");";
 
+    return cql3::description {
+        .keyspace = _keyspace,
+        .type = "type",
+        .name = get_name_as_string(),
+        .create_statement = std::move(os).str()
+    };
+}
+
+std::ostream& user_type_impl::describe(std::ostream& os) const {
+    auto desc = describe();
+    os << *desc.create_statement;
     return os;
 }
 

types/user.hh

@@ -8,6 +8,7 @@
 
 #pragma once
 
+#include "cql3/description.hh"
 #include "types/types.hh"
 #include "types/tuple.hh"
 #include "data_dictionary/keyspace_element.hh"
@@ -64,6 +65,8 @@ public:
     virtual sstring element_type() const override { return "type"; }
     virtual std::ostream& describe(std::ostream& os) const override;
 
+    cql3::description describe() const;
+
 private:
     static sstring make_name(sstring keyspace,
                              bytes name,