/* */ /* * Copyright (C) 2019-present ScyllaDB * * Modified by ScyllaDB */ /* * SPDX-License-Identifier: (AGPL-3.0-or-later and Apache-2.0) */ #include "mutation.hh" #include "modification_statement.hh" #include "cas_request.hh" #include #include "cql3/result_set.hh" #include "transport/messages/result_message.hh" #include "types/map.hh" #include "service/storage_proxy.hh" #include "cql3/query_processor.hh" namespace cql3::statements { using namespace std::chrono; void cas_request::add_row_update(const modification_statement& stmt_arg, std::vector ranges_arg, modification_statement::json_cache_opt json_cache_arg, const query_options& options_arg) { // TODO: reserve updates array for batches _updates.emplace_back(cas_row_update{ .statement = stmt_arg, .ranges = std::move(ranges_arg), .json_cache = std::move(json_cache_arg), .options = options_arg}); } std::optional cas_request::apply_updates(api::timestamp_type ts) const { // We're working with a single partition, so there will be only one element // in the vector. A vector is used since this is a conventional format // to pass a mutation onward. std::optional mutation_set; for (const cas_row_update& op: _updates) { update_parameters params(_schema, op.options, ts, op.statement.get_time_to_live(op.options), _rows); std::vector statement_mutations = op.statement.apply_updates(_key, op.ranges, params, op.json_cache); // Append all mutations (in fact only one) to the consolidated one. for (mutation& m : statement_mutations) { if (mutation_set.has_value() == false) { mutation_set.emplace(std::move(m)); } else { mutation_set->apply(std::move(m)); } } } return mutation_set; } lw_shared_ptr cas_request::read_command(query_processor& qp) const { column_set columns_to_read(_schema->all_columns_count()); std::vector ranges; for (const cas_row_update& op : _updates) { if (op.statement.has_conditions() == false && op.statement.requires_read() == false) { // No point in pre-fetching the old row if the statement doesn't check it in a CAS and // doesn't use it to apply updates. continue; } columns_to_read.union_with(op.statement.columns_to_read()); if (op.statement.has_only_static_column_conditions() && !op.statement.requires_read()) { // If a statement has only static column conditions and doesn't have operations that // require read, it doesn't matter what clustering key range to query - any partition // row will do for the check. continue; } ranges.reserve(op.ranges.size()); std::copy(op.ranges.begin(), op.ranges.end(), std::back_inserter(ranges)); } uint64_t max_rows = query::partition_max_rows; if (ranges.empty()) { // With only a static condition, we still want to make the distinction between // a non-existing partition and one that exists (has some live data) but has not // static content. So we query the first live row of the partition. ranges.emplace_back(query::clustering_range::make_open_ended_both_sides()); max_rows = 1; } else { ranges = query::clustering_range::deoverlap(std::move(ranges), clustering_key::tri_compare(*_schema)); } auto options = update_parameters::options; options.set(query::partition_slice::option::always_return_static_content); query::partition_slice ps(std::move(ranges), *_schema, columns_to_read, options); ps.set_partition_row_limit(max_rows); return make_lw_shared(_schema->id(), _schema->version(), std::move(ps), qp.proxy().get_max_result_size(ps)); } bool cas_request::applies_to() const { for (const cas_row_update& op: _updates) { if (!op.statement.has_conditions()) { continue; } // No need to check subsequent conditions as we have already failed the current one. if (!op.statement.applies_to(find_old_row(op), op.options)) { return false; } } return true; } std::optional cas_request::apply(foreign_ptr> qr, const query::partition_slice& slice, api::timestamp_type ts) { _rows = update_parameters::build_prefetch_data(_schema, *qr, slice); if (applies_to()) { return apply_updates(ts); } else { return {}; } } const update_parameters::prefetch_data::row* cas_request::find_old_row(const cas_row_update& op) const { static const clustering_key empty_ckey = clustering_key::make_empty(); const partition_key& pkey = _key.front().start()->value().key().value(); // If a statement has only static columns conditions, we must ignore its clustering columns // restriction when choosing a row to check the conditions, i.e. choose any partition row, // because any of them must have static columns and that's all we need to know if the // statement applies. For example, the following update must successfully apply (effectively // turn into INSERT), because, although the table doesn't have any regular rows matching the // statement clustering column restriction, the static row matches the statement condition: // CREATE TABLE t(p int, c int, s int static, v int, PRIMARY KEY(p, c)); // INSERT INTO t(p, s) VALUES(1, 1); // UPDATE t SET v=1 WHERE p=1 AND c=1 IF s=1; // Another case when we pass an empty clustering key prefix is apparently when the table // doesn't have any clustering key columns and the clustering key range is empty (open // ended on both sides). const clustering_key& ckey = !op.statement.has_only_static_column_conditions() && op.ranges.front().start() ? op.ranges.front().start()->value() : empty_ckey; return _rows.find_row(pkey, ckey); } seastar::shared_ptr cas_request::build_cas_result_set(seastar::shared_ptr metadata, const column_set& columns, bool is_applied) const { const partition_key& pkey = _key.front().start()->value().key().value(); const clustering_key empty_ckey = clustering_key::make_empty(); auto result_set = std::make_unique(metadata); for (const cas_row_update& op: _updates) { // Construct the result set row std::vector rs_row; rs_row.reserve(metadata->value_count()); rs_row.emplace_back(boolean_type->decompose(is_applied)); // Get old row from prefetched data for the row update const auto* old_row = find_old_row(op); if (!old_row) { if (!op.statement.has_static_column_conditions()) { // In case there is no old row, leave all other columns null // so that we can infer whether the update attempts to insert a // non-existing row. rs_row.resize(metadata->value_count()); result_set->add_row(std::move(rs_row)); continue; } // If none of the fetched rows matches clustering key restrictions, // but there is a static column condition in the CAS batch, // we must still include the static row into the result set. Consider the following example: // CREATE TABLE t(p int, c int, s int static, v int, PRIMARY KEY(p, c)); // INSERT INTO t(p, s) VALUES(1, 1); // DELETE v FROM t WHERE p=1 AND c=1 IF v=1 AND s=1; // In this case the conditional DELETE must return [applied=False, v=null, s=1]. old_row = _rows.find_row(pkey, empty_ckey); if (!old_row) { // In case there is no old row, leave all other columns null // so that we can infer whether the update attempts to insert a // non-existing row. rs_row.resize(metadata->value_count()); result_set->add_row(std::move(rs_row)); continue; } } // Fill in the cells from prefetch data (old row) into the result set row for (ordinal_column_id id = columns.find_first(); id != column_set::npos; id = columns.find_next(id)) { const auto it = old_row->cells.find(id); if (it == old_row->cells.end()) { rs_row.emplace_back(bytes_opt{}); continue; } const data_value& cell = it->second; const abstract_type& cell_type = *cell.type(); const abstract_type& column_type = *_rows.schema->column_at(id).type; if (column_type.is_listlike() && cell_type.is_map()) { // List/sets are fetched as maps, but need to be stored as sets. const listlike_collection_type_impl& list_type = static_cast(column_type); const map_type_impl& map_type = static_cast(cell_type); rs_row.emplace_back(list_type.serialize_map(map_type, cell)); } else { rs_row.emplace_back(cell_type.decompose(cell)); } } result_set->add_row(std::move(rs_row)); } cql3::result result(std::move(result_set)); return seastar::make_shared(std::move(result)); } } // end of namespace "cql3::statements"