Files
scylladb/cql3/selection/selectable.cc
Jan Ciolek 818e3544bb cql3: Handle subscript in selectable_process_selection
Selected values can't subscripted, the grammar in Cql.g doesn't allow it.

Signed-off-by: Jan Ciolek <jan.ciolek@scylladb.com>
2022-02-27 21:56:41 +01:00

314 lines
14 KiB
C++

/*
* Copyright (C) 2015-present ScyllaDB
*/
/*
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
#include "selectable.hh"
#include "selectable_with_field_selection.hh"
#include "field_selector.hh"
#include "writetime_or_ttl.hh"
#include "selector_factories.hh"
#include "simple_selector.hh"
#include "cql3/query_options.hh"
#include "cql3/functions/functions.hh"
#include "cql3/functions/castas_fcts.hh"
#include "cql3/functions/aggregate_fcts.hh"
#include "cql3/expr/expression.hh"
#include "abstract_function_selector.hh"
#include "writetime_or_ttl_selector.hh"
namespace cql3 {
namespace selection {
seastar::logger slogger("cql3_selection");
class selectable_column : public selectable {
column_identifier _ci;
public:
explicit selectable_column(column_identifier ci) : _ci(std::move(ci)) {}
virtual ::shared_ptr<selector::factory> new_selector_factory(data_dictionary::database db, schema_ptr schema,
std::vector<const column_definition*>& defs) override;
virtual sstring to_string() const override {
return _ci.to_string();
}
};
::shared_ptr<selector::factory>
selectable_column::new_selector_factory(data_dictionary::database db, schema_ptr schema, std::vector<const column_definition*>& defs) {
auto def = get_column_definition(*schema, _ci);
if (!def) {
throw exceptions::invalid_request_exception(format("Undefined name {} in selection clause", _ci.text()));
}
// Do not allow explicitly selecting hidden columns. We also skip them on
// "SELECT *" (see selection::wildcard()).
if (def->is_hidden_from_cql()) {
throw exceptions::invalid_request_exception(format("Undefined name {} in selection clause", _ci.text()));
}
return simple_selector::new_factory(def->name_as_text(), add_and_get_index(*def, defs), def->type);
}
shared_ptr<selector::factory>
selectable::writetime_or_ttl::new_selector_factory(data_dictionary::database db, schema_ptr s, std::vector<const column_definition*>& defs) {
auto&& def = s->get_column_definition(_id->name());
if (!def || def->is_hidden_from_cql()) {
throw exceptions::invalid_request_exception(format("Undefined name {} in selection clause", _id));
}
if (def->is_primary_key()) {
throw exceptions::invalid_request_exception(
format("Cannot use selection function {} on PRIMARY KEY part {}",
_is_writetime ? "writeTime" : "ttl",
def->name()));
}
if (def->type->is_multi_cell()) {
throw exceptions::invalid_request_exception(format("Cannot use selection function {} on non-frozen collections",
_is_writetime ? "writeTime" : "ttl"));
}
return writetime_or_ttl_selector::new_factory(def->name_as_text(), add_and_get_index(*def, defs), _is_writetime);
}
sstring
selectable::writetime_or_ttl::to_string() const {
return format("{}({})", _is_writetime ? "writetime" : "ttl", _id->to_string());
}
shared_ptr<selector::factory>
selectable::with_function::new_selector_factory(data_dictionary::database db, schema_ptr s, std::vector<const column_definition*>& defs) {
auto&& factories = selector_factories::create_factories_and_collect_column_definitions(_args, db, s, defs);
// resolve built-in functions before user defined functions
auto&& fun = functions::functions::get(db, s->ks_name(), _function_name, factories->new_instances(), s->ks_name(), s->cf_name());
if (!fun) {
throw exceptions::invalid_request_exception(format("Unknown function '{}'", _function_name));
}
if (!fun->return_type()) {
throw exceptions::invalid_request_exception(format("Unknown function {} called in selection clause", _function_name));
}
return abstract_function_selector::new_factory(std::move(fun), std::move(factories));
}
sstring
selectable::with_function::to_string() const {
return format("{}({})", _function_name.name, join(", ", _args));
}
expr::expression
make_count_rows_function_expression() {
return expr::function_call{
cql3::functions::function_name::native_function(cql3::functions::aggregate_fcts::COUNT_ROWS_FUNCTION_NAME),
std::vector<cql3::expr::expression>()};
}
shared_ptr<selector::factory>
selectable::with_anonymous_function::new_selector_factory(data_dictionary::database db, schema_ptr s, std::vector<const column_definition*>& defs) {
auto&& factories = selector_factories::create_factories_and_collect_column_definitions(_args, db, s, defs);
return abstract_function_selector::new_factory(_function, std::move(factories));
}
sstring
selectable::with_anonymous_function::to_string() const {
return format("{}({})", _function->name().name, join(", ", _args));
}
shared_ptr<selector::factory>
selectable::with_field_selection::new_selector_factory(data_dictionary::database db, schema_ptr s, std::vector<const column_definition*>& defs) {
auto&& factory = _selected->new_selector_factory(db, s, defs);
auto&& type = factory->new_instance()->get_type();
if (!type->underlying_type()->is_user_type()) {
throw exceptions::invalid_request_exception(
format("Invalid field selection: {} of type {} is not a user type", _selected->to_string(), type->as_cql3_type()));
}
auto ut = static_pointer_cast<const user_type_impl>(type->underlying_type());
auto idx = ut->idx_of_field(_field->bytes_);
if (!idx) {
throw exceptions::invalid_request_exception(format("{} of type {} has no field {}",
_selected->to_string(), ut->as_cql3_type(), _field));
}
return field_selector::new_factory(std::move(ut), *idx, std::move(factory));
}
sstring
selectable::with_field_selection::to_string() const {
return format("{}.{}", _selected->to_string(), _field->to_string());
}
shared_ptr<selector::factory>
selectable::with_cast::new_selector_factory(data_dictionary::database db, schema_ptr s, std::vector<const column_definition*>& defs) {
std::vector<shared_ptr<selectable>> args{_arg};
auto&& factories = selector_factories::create_factories_and_collect_column_definitions(args, db, s, defs);
auto&& fun = functions::castas_functions::get(_type.get_type(), factories->new_instances());
return abstract_function_selector::new_factory(std::move(fun), std::move(factories));
}
sstring
selectable::with_cast::to_string() const {
return format("cast({} as {})", _arg->to_string(), _type.to_string());
}
shared_ptr<selectable>
prepare_selectable(const schema& s, const expr::expression& raw_selectable) {
return expr::visit(overloaded_functor{
[&] (const expr::constant&) -> shared_ptr<selectable> {
on_internal_error(slogger, "no way to express SELECT constant in the grammar yet");
},
[&] (const expr::conjunction& conj) -> shared_ptr<selectable> {
on_internal_error(slogger, "no way to express 'SELECT a AND b' in the grammar yet");
},
[&] (const expr::binary_operator& conj) -> shared_ptr<selectable> {
on_internal_error(slogger, "no way to express 'SELECT a binop b' in the grammar yet");
},
[&] (const expr::column_value& column) -> shared_ptr<selectable> {
// There is no path that reaches here, but expr::column_value and selectable_column are logically the same,
// so bridge them.
return ::make_shared<selectable_column>(column_identifier(column.col->name(), column.col->name_as_text()));
},
[&] (const expr::subscript& sub) -> shared_ptr<selectable> {
on_internal_error(slogger, "no way to express 'SELECT a[b]' in the grammar yet");
},
[&] (const expr::token& tok) -> shared_ptr<selectable> {
// expr::token implicitly the partition key as arguments, but
// the selectable equivalent (with_function) needs explicit arguments,
// so construct them here.
auto name = functions::function_name("system", "token");
auto args = boost::copy_range<std::vector<shared_ptr<selectable>>>(
s.partition_key_columns()
| boost::adaptors::transformed([&] (const column_definition& cdef) {
return ::make_shared<selectable_column>(column_identifier(cdef.name(), cdef.name_as_text()));
}));
return ::make_shared<selectable::with_function>(std::move(name), std::move(args));
},
[&] (const expr::unresolved_identifier& ui) -> shared_ptr<selectable> {
return make_shared<selectable_column>(*ui.ident->prepare(s));
},
[&] (const expr::column_mutation_attribute& cma) -> shared_ptr<selectable> {
auto unresolved_id = expr::as<expr::unresolved_identifier>(cma.column);
bool is_writetime = cma.kind == expr::column_mutation_attribute::attribute_kind::writetime;
return make_shared<selectable::writetime_or_ttl>(unresolved_id.ident->prepare_column_identifier(s), is_writetime);
},
[&] (const expr::function_call& fc) -> shared_ptr<selectable> {
std::vector<shared_ptr<selectable>> prepared_args;
prepared_args.reserve(fc.args.size());
for (auto&& arg : fc.args) {
prepared_args.push_back(prepare_selectable(s, arg));
}
return std::visit(overloaded_functor{
[&] (const functions::function_name& named) -> shared_ptr<selectable> {
return ::make_shared<selectable::with_function>(named, std::move(prepared_args));
},
[&] (const shared_ptr<functions::function>& anon) -> shared_ptr<selectable> {
return ::make_shared<selectable::with_anonymous_function>(anon, std::move(prepared_args));
},
}, fc.func);
},
[&] (const expr::cast& c) -> shared_ptr<selectable> {
auto t = std::get_if<cql3_type>(&c.type);
if (!t) {
// FIXME: adjust prepare_seletable() signature so we can prepare the type too
on_internal_error(slogger, "unprepared type in selector type cast");
}
return ::make_shared<selectable::with_cast>(prepare_selectable(s, c.arg), *t);
},
[&] (const expr::field_selection& fs) -> shared_ptr<selectable> {
// static_pointer_cast<> needed due to lack of covariant return type
// support with smart pointers
return make_shared<selectable::with_field_selection>(prepare_selectable(s, fs.structure),
fs.field->prepare(s));
},
[&] (const expr::null&) -> shared_ptr<selectable> {
on_internal_error(slogger, "null found its way to selector context");
},
[&] (const expr::bind_variable&) -> shared_ptr<selectable> {
on_internal_error(slogger, "bind_variable found its way to selector context");
},
[&] (const expr::untyped_constant&) -> shared_ptr<selectable> {
on_internal_error(slogger, "untyped_constant found its way to selector context");
},
[&] (const expr::tuple_constructor&) -> shared_ptr<selectable> {
on_internal_error(slogger, "tuple_constructor found its way to selector context");
},
[&] (const expr::collection_constructor&) -> shared_ptr<selectable> {
on_internal_error(slogger, "collection_constructor found its way to selector context");
},
[&] (const expr::usertype_constructor&) -> shared_ptr<selectable> {
on_internal_error(slogger, "usertype_constructor found its way to selector context");
},
}, raw_selectable);
}
bool
selectable_processes_selection(const expr::expression& raw_selectable) {
return expr::visit(overloaded_functor{
[&] (const expr::constant&) -> bool {
on_internal_error(slogger, "no way to express SELECT constant in the grammar yet");
},
[&] (const expr::conjunction& conj) -> bool {
on_internal_error(slogger, "no way to express 'SELECT a AND b' in the grammar yet");
},
[&] (const expr::binary_operator& conj) -> bool {
on_internal_error(slogger, "no way to express 'SELECT a binop b' in the grammar yet");
},
[] (const expr::subscript&) -> bool {
on_internal_error(slogger, "no way to express 'SELECT a[b]' in the grammar yet");
},
[&] (const expr::column_value& column) -> bool {
// There is no path that reaches here, but expr::column_value and column_identifier are logically the same,
// so bridge them.
return false;
},
[&] (const expr::token&) -> bool {
// Arguably, should return false, because it only processes the partition key.
// But selectable::with_function considers it true now, so return that.
return true;
},
[&] (const expr::unresolved_identifier& ui) -> bool {
return ui.ident->processes_selection();
},
[&] (const expr::column_mutation_attribute& cma) -> bool {
return true;
},
[&] (const expr::function_call& fc) -> bool {
return true;
},
[&] (const expr::cast& c) -> bool {
return true;
},
[&] (const expr::field_selection& fs) -> bool {
return true;
},
[&] (const expr::null&) -> bool {
on_internal_error(slogger, "null found its way to selector context");
},
[&] (const expr::bind_variable&) -> bool {
on_internal_error(slogger, "bind_variable found its way to selector context");
},
[&] (const expr::untyped_constant&) -> bool {
on_internal_error(slogger, "untyped_constant found its way to selector context");
},
[&] (const expr::tuple_constructor&) -> bool {
on_internal_error(slogger, "tuple_constructor found its way to selector context");
},
[&] (const expr::collection_constructor&) -> bool {
on_internal_error(slogger, "collection_constructor found its way to selector context");
},
[&] (const expr::usertype_constructor&) -> bool {
on_internal_error(slogger, "collection_constructor found its way to selector context");
},
}, raw_selectable);
};
std::ostream & operator<<(std::ostream &os, const selectable& s) {
return os << s.to_string();
}
}
}