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scylladb/alternator/expressions.hh
Avi Kivity 0ae22a09d4 LICENSE: Update to version 1.1
Updated terms of non-commercial use (must be a never-customer).
2026-04-12 19:46:33 +03:00

120 lines
4.2 KiB
C++

/*
* Copyright 2019-present ScyllaDB
*/
/*
* SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.1
*/
#pragma once
#include <string>
#include <stdexcept>
#include <vector>
#include <unordered_set>
#include <string_view>
#include <seastar/util/noncopyable_function.hh>
#include "expressions_types.hh"
#include "utils/rjson.hh"
#include "utils/updateable_value.hh"
#include "stats.hh"
namespace alternator {
class expressions_syntax_error : public std::runtime_error {
public:
using runtime_error::runtime_error;
};
namespace parsed {
class expression_cache_impl;
class expression_cache {
std::unique_ptr<expression_cache_impl> _impl;
public:
struct config {
utils::updateable_value<uint32_t> max_cache_entries;
};
expression_cache(config cfg, stats& stats);
~expression_cache();
// stop background tasks, if any
future<> stop();
update_expression parse_update_expression(std::string_view query);
std::vector<path> parse_projection_expression(std::string_view query);
condition_expression parse_condition_expression(std::string_view query, const char* caller);
};
} // namespace parsed
// Preferably use parsed::expression_cache instance instead of this free functions.
parsed::update_expression parse_update_expression(std::string_view query);
std::vector<parsed::path> parse_projection_expression(std::string_view query);
parsed::condition_expression parse_condition_expression(std::string_view query, const char* caller);
void resolve_update_expression(parsed::update_expression& ue,
const rjson::value* expression_attribute_names,
const rjson::value* expression_attribute_values,
std::unordered_set<std::string>& used_attribute_names,
std::unordered_set<std::string>& used_attribute_values);
void resolve_projection_expression(std::vector<parsed::path>& pe,
const rjson::value* expression_attribute_names,
std::unordered_set<std::string>& used_attribute_names);
void resolve_condition_expression(parsed::condition_expression& ce,
const rjson::value* expression_attribute_names,
const rjson::value* expression_attribute_values,
std::unordered_set<std::string>& used_attribute_names,
std::unordered_set<std::string>& used_attribute_values);
void validate_value(const rjson::value& v, const char* caller);
bool condition_expression_on(const parsed::condition_expression& ce, std::string_view attribute);
// for_condition_expression_on() runs the given function on the attributes
// that the expression uses. It may run for the same attribute more than once
// if the same attribute is used more than once in the expression.
void for_condition_expression_on(const parsed::condition_expression& ce, const noncopyable_function<void(std::string_view)>& func);
// calculate_value() behaves slightly different (especially, different
// functions supported) when used in different types of expressions, as
// enumerated in this enum:
enum class calculate_value_caller {
UpdateExpression, ConditionExpression, ConditionExpressionAlone
};
}
template <> struct fmt::formatter<alternator::calculate_value_caller> {
constexpr auto parse(format_parse_context& ctx) { return ctx.begin(); }
auto format(alternator::calculate_value_caller caller, fmt::format_context& ctx) const {
std::string_view name = "unknown type of expression";
switch (caller) {
using enum alternator::calculate_value_caller;
case UpdateExpression:
name = "UpdateExpression";
break;
case ConditionExpression:
name = "ConditionExpression";
break;
case ConditionExpressionAlone:
name = "ConditionExpression";
break;
}
return fmt::format_to(ctx.out(), "{}", name);
}
};
namespace alternator {
rjson::value calculate_value(const parsed::value& v,
calculate_value_caller caller,
const rjson::value* previous_item);
rjson::value calculate_value(const parsed::set_rhs& rhs,
const rjson::value* previous_item);
void validate_attr_name_length(std::string_view supplementary_context, size_t attr_name_length, bool is_key, std::string_view error_msg_prefix = {});
} /* namespace alternator */