Files
scylladb/cql3/selection/selection.cc
Piotr Sarna 87c23372fb cql3: fix filtering with LIMIT with regard to paging
Previously the limit was erroneously applied per page
instead of being accumulated, which might have caused returning
too many rows. As of now, LIMIT is handled properly inside
restrictions filter.

Fixes #4100
2019-01-17 13:25:09 +01:00

461 lines
18 KiB
C++

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
/*
* Copyright (C) 2015 ScyllaDB
*
* Modified by ScyllaDB
*/
/*
* This file is part of Scylla.
*
* Scylla is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Scylla is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
*/
#include <boost/range/adaptor/transformed.hpp>
#include <boost/range/adaptor/filtered.hpp>
#include "cql3/selection/selection.hh"
#include "cql3/selection/selector_factories.hh"
#include "cql3/result_set.hh"
namespace cql3 {
namespace selection {
selection::selection(schema_ptr schema,
std::vector<const column_definition*> columns,
std::vector<::shared_ptr<column_specification>> metadata_,
bool collect_timestamps,
bool collect_TTLs,
trivial is_trivial)
: _schema(std::move(schema))
, _columns(std::move(columns))
, _metadata(::make_shared<metadata>(std::move(metadata_)))
, _collect_timestamps(collect_timestamps)
, _collect_TTLs(collect_TTLs)
, _contains_static_columns(std::any_of(_columns.begin(), _columns.end(), std::mem_fn(&column_definition::is_static)))
, _is_trivial(is_trivial)
{ }
query::partition_slice::option_set selection::get_query_options() {
query::partition_slice::option_set opts;
opts.set_if<query::partition_slice::option::send_timestamp>(_collect_timestamps);
opts.set_if<query::partition_slice::option::send_expiry>(_collect_TTLs);
opts.set_if<query::partition_slice::option::send_partition_key>(
std::any_of(_columns.begin(), _columns.end(),
std::mem_fn(&column_definition::is_partition_key)));
opts.set_if<query::partition_slice::option::send_clustering_key>(
std::any_of(_columns.begin(), _columns.end(),
std::mem_fn(&column_definition::is_clustering_key)));
return opts;
}
// Special cased selection for when no function is used (this save some allocations).
class simple_selection : public selection {
private:
const bool _is_wildcard;
public:
static ::shared_ptr<simple_selection> make(schema_ptr schema, std::vector<const column_definition*> columns, bool is_wildcard) {
std::vector<::shared_ptr<column_specification>> metadata;
metadata.reserve(columns.size());
for (auto&& col : columns) {
metadata.emplace_back(col->column_specification);
}
return ::make_shared<simple_selection>(schema, std::move(columns), std::move(metadata), is_wildcard);
}
/*
* In theory, even a simple selection could have multiple time the same column, so we
* could filter those duplicate out of columns. But since we're very unlikely to
* get much duplicate in practice, it's more efficient not to bother.
*/
simple_selection(schema_ptr schema, std::vector<const column_definition*> columns,
std::vector<::shared_ptr<column_specification>> metadata, bool is_wildcard)
: selection(schema, std::move(columns), std::move(metadata), false, false, trivial::yes)
, _is_wildcard(is_wildcard)
{ }
virtual bool is_wildcard() const override { return _is_wildcard; }
virtual bool is_aggregate() const override { return false; }
protected:
class simple_selectors : public selectors {
private:
std::vector<bytes_opt> _current;
public:
virtual void reset() override {
_current.clear();
}
virtual std::vector<bytes_opt> get_output_row(cql_serialization_format sf) override {
return std::move(_current);
}
virtual void add_input_row(cql_serialization_format sf, result_set_builder& rs) override {
_current = std::move(*rs.current);
}
virtual bool is_aggregate() {
return false;
}
};
std::unique_ptr<selectors> new_selectors() const override {
return std::make_unique<simple_selectors>();
}
};
class selection_with_processing : public selection {
private:
::shared_ptr<selector_factories> _factories;
public:
selection_with_processing(schema_ptr schema, std::vector<const column_definition*> columns,
std::vector<::shared_ptr<column_specification>> metadata, ::shared_ptr<selector_factories> factories)
: selection(schema, std::move(columns), std::move(metadata),
factories->contains_write_time_selector_factory(),
factories->contains_ttl_selector_factory())
, _factories(std::move(factories))
{
if (_factories->does_aggregation() && !_factories->contains_only_aggregate_functions()) {
throw exceptions::invalid_request_exception("the select clause must either contains only aggregates or none");
}
}
virtual bool uses_function(const sstring& ks_name, const sstring& function_name) const override {
return _factories->uses_function(ks_name, function_name);
}
virtual uint32_t add_column_for_post_processing(const column_definition& c) override {
uint32_t index = selection::add_column_for_post_processing(c);
_factories->add_selector_for_post_processing(c, index);
return index;
}
virtual bool is_aggregate() const override {
return _factories->contains_only_aggregate_functions();
}
protected:
class selectors_with_processing : public selectors {
private:
::shared_ptr<selector_factories> _factories;
std::vector<::shared_ptr<selector>> _selectors;
public:
selectors_with_processing(::shared_ptr<selector_factories> factories)
: _factories(std::move(factories))
, _selectors(_factories->new_instances())
{ }
virtual void reset() override {
for (auto&& s : _selectors) {
s->reset();
}
}
virtual bool is_aggregate() override {
return _factories->contains_only_aggregate_functions();
}
virtual std::vector<bytes_opt> get_output_row(cql_serialization_format sf) override {
std::vector<bytes_opt> output_row;
output_row.reserve(_selectors.size());
for (auto&& s : _selectors) {
output_row.emplace_back(s->get_output(sf));
}
return output_row;
}
virtual void add_input_row(cql_serialization_format sf, result_set_builder& rs) {
for (auto&& s : _selectors) {
s->add_input(sf, rs);
}
}
};
std::unique_ptr<selectors> new_selectors() const override {
return std::make_unique<selectors_with_processing>(_factories);
}
};
::shared_ptr<selection> selection::wildcard(schema_ptr schema) {
auto columns = schema->all_columns_in_select_order();
// filter out hidden columns, which should not be seen by the
// user when doing "SELECT *". We also disallow selecting them
// individually (see column_identifier::new_selector_factory()).
auto cds = boost::copy_range<std::vector<const column_definition*>>(
columns |
boost::adaptors::filtered([](const column_definition& c) {
return !c.is_view_virtual();
}) |
boost::adaptors::transformed([](const column_definition& c) {
return &c;
}));
return simple_selection::make(schema, std::move(cds), true);
}
::shared_ptr<selection> selection::for_columns(schema_ptr schema, std::vector<const column_definition*> columns) {
return simple_selection::make(schema, std::move(columns), false);
}
uint32_t selection::add_column_for_post_processing(const column_definition& c) {
_columns.push_back(&c);
_metadata->add_non_serialized_column(c.column_specification);
return _columns.size() - 1;
}
::shared_ptr<selection> selection::from_selectors(database& db, schema_ptr schema, const std::vector<::shared_ptr<raw_selector>>& raw_selectors) {
std::vector<const column_definition*> defs;
::shared_ptr<selector_factories> factories =
selector_factories::create_factories_and_collect_column_definitions(
raw_selector::to_selectables(raw_selectors, schema), db, schema, defs);
auto metadata = collect_metadata(schema, raw_selectors, *factories);
if (processes_selection(raw_selectors) || raw_selectors.size() != defs.size()) {
return ::make_shared<selection_with_processing>(schema, std::move(defs), std::move(metadata), std::move(factories));
} else {
return ::make_shared<simple_selection>(schema, std::move(defs), std::move(metadata), false);
}
}
std::vector<::shared_ptr<column_specification>>
selection::collect_metadata(schema_ptr schema, const std::vector<::shared_ptr<raw_selector>>& raw_selectors,
const selector_factories& factories) {
std::vector<::shared_ptr<column_specification>> r;
r.reserve(raw_selectors.size());
auto i = raw_selectors.begin();
for (auto&& factory : factories) {
::shared_ptr<column_specification> col_spec = factory->get_column_specification(schema);
::shared_ptr<column_identifier> alias = (*i++)->alias;
r.push_back(alias ? col_spec->with_alias(alias) : col_spec);
}
return r;
}
result_set_builder::result_set_builder(const selection& s, gc_clock::time_point now, cql_serialization_format sf)
: _result_set(std::make_unique<result_set>(::make_shared<metadata>(*(s.get_result_metadata()))))
, _selectors(s.new_selectors())
, _now(now)
, _cql_serialization_format(sf)
{
if (s._collect_timestamps) {
_timestamps.resize(s._columns.size(), 0);
}
if (s._collect_TTLs) {
_ttls.resize(s._columns.size(), 0);
}
}
void result_set_builder::add_empty() {
current->emplace_back();
if (!_timestamps.empty()) {
_timestamps[current->size() - 1] = api::missing_timestamp;
}
if (!_ttls.empty()) {
_ttls[current->size() - 1] = -1;
}
}
void result_set_builder::add(bytes_opt value) {
current->emplace_back(std::move(value));
}
void result_set_builder::add(const column_definition& def, const query::result_atomic_cell_view& c) {
current->emplace_back(get_value(def.type, c));
if (!_timestamps.empty()) {
_timestamps[current->size() - 1] = c.timestamp();
}
if (!_ttls.empty()) {
gc_clock::duration ttl_left(-1);
expiry_opt e = c.expiry();
if (e) {
ttl_left = *e - _now;
}
_ttls[current->size() - 1] = ttl_left.count();
}
}
void result_set_builder::add_collection(const column_definition& def, bytes_view c) {
current->emplace_back(to_bytes(c));
// timestamps, ttls meaningless for collections
}
void result_set_builder::new_row() {
if (current) {
_selectors->add_input_row(_cql_serialization_format, *this);
if (!_selectors->is_aggregate()) {
_result_set->add_row(_selectors->get_output_row(_cql_serialization_format));
_selectors->reset();
}
current->clear();
} else {
// FIXME: we use optional<> here because we don't have an end_row() signal
// instead, !current means that new_row has never been called, so this
// call to new_row() does not end a previous row.
current.emplace();
}
}
std::unique_ptr<result_set> result_set_builder::build() {
if (current) {
_selectors->add_input_row(_cql_serialization_format, *this);
_result_set->add_row(_selectors->get_output_row(_cql_serialization_format));
_selectors->reset();
current = std::nullopt;
}
if (_result_set->empty() && _selectors->is_aggregate()) {
_result_set->add_row(_selectors->get_output_row(_cql_serialization_format));
}
return std::move(_result_set);
}
bool result_set_builder::restrictions_filter::do_filter(const selection& selection,
const std::vector<bytes>& partition_key,
const std::vector<bytes>& clustering_key,
const query::result_row_view& static_row,
const query::result_row_view& row) const {
static logging::logger rlogger("restrictions_filter");
if (_current_partition_key_does_not_match || _current_static_row_does_not_match || _remaining == 0) {
return false;
}
auto static_row_iterator = static_row.iterator();
auto row_iterator = row.iterator();
auto non_pk_restrictions_map = _restrictions->get_non_pk_restriction();
for (auto&& cdef : selection.get_columns()) {
switch (cdef->kind) {
case column_kind::static_column:
// fallthrough
case column_kind::regular_column: {
auto& cell_iterator = (cdef->kind == column_kind::static_column) ? static_row_iterator : row_iterator;
std::optional<query::result_bytes_view> result_view_opt;
if (cdef->type->is_multi_cell()) {
result_view_opt = cell_iterator.next_collection_cell();
} else {
auto cell = cell_iterator.next_atomic_cell();
if (cell) {
result_view_opt = cell->value();
}
}
auto restr_it = non_pk_restrictions_map.find(cdef);
if (restr_it == non_pk_restrictions_map.end()) {
continue;
}
restrictions::single_column_restriction& restriction = *restr_it->second;
bool regular_restriction_matches;
if (result_view_opt) {
regular_restriction_matches = result_view_opt->with_linearized([&restriction, this](bytes_view data) {
return restriction.is_satisfied_by(data, _options);
});
} else {
regular_restriction_matches = restriction.is_satisfied_by(bytes(), _options);
}
if (!regular_restriction_matches) {
_current_static_row_does_not_match = (cdef->kind == column_kind::static_column);
return false;
}
}
break;
case column_kind::partition_key: {
if (_skip_pk_restrictions) {
continue;
}
auto partition_key_restrictions_map = _restrictions->get_single_column_partition_key_restrictions();
auto restr_it = partition_key_restrictions_map.find(cdef);
if (restr_it == partition_key_restrictions_map.end()) {
continue;
}
restrictions::single_column_restriction& restriction = *restr_it->second;
const bytes& value_to_check = partition_key[cdef->id];
bool pk_restriction_matches = restriction.is_satisfied_by(value_to_check, _options);
if (!pk_restriction_matches) {
_current_partition_key_does_not_match = true;
return false;
}
}
break;
case column_kind::clustering_key: {
if (_skip_ck_restrictions) {
continue;
}
auto clustering_key_restrictions_map = _restrictions->get_single_column_clustering_key_restrictions();
auto restr_it = clustering_key_restrictions_map.find(cdef);
if (restr_it == clustering_key_restrictions_map.end()) {
continue;
}
restrictions::single_column_restriction& restriction = *restr_it->second;
const bytes& value_to_check = clustering_key[cdef->id];
bool pk_restriction_matches = restriction.is_satisfied_by(value_to_check, _options);
if (!pk_restriction_matches) {
return false;
}
}
break;
default:
break;
}
}
return true;
}
bool result_set_builder::restrictions_filter::operator()(const selection& selection,
const std::vector<bytes>& partition_key,
const std::vector<bytes>& clustering_key,
const query::result_row_view& static_row,
const query::result_row_view& row) const {
const bool accepted = do_filter(selection, partition_key, clustering_key, static_row, row);
if (!accepted) {
++_rows_dropped;
} else if (_remaining > 0) {
--_remaining;
}
return accepted;
}
api::timestamp_type result_set_builder::timestamp_of(size_t idx) {
return _timestamps[idx];
}
int32_t result_set_builder::ttl_of(size_t idx) {
return _ttls[idx];
}
bytes_opt result_set_builder::get_value(data_type t, query::result_atomic_cell_view c) {
return {c.value().linearize()};
}
}
}