Files
scylladb/cql3/util.hh
Avi Kivity c0ba7040d5 cql3: grammar: don't default-construct expressions
Use uninitialized<expression> for that. Since it's heavily used,
alias it as "uexpression".

To prevent uninitialized<> from leaking into the rest of the
system, change do_with_parser() to unwrap it. We add an
unwrap_uninitialized_t template type alias for that.

Lots of std::move()s are sprinkled around to make things compile,
as uninitialized<T> refuses to convert to T without them.
2023-07-14 18:33:06 +03:00

98 lines
4.0 KiB
C++

/*
* Copyright (C) 2016-present ScyllaDB
*
* Modified by ScyllaDB
*/
/*
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
#pragma once
#include <vector>
#include <boost/algorithm/string/join.hpp>
#include <boost/range/adaptor/transformed.hpp>
#include <seastar/core/sstring.hh>
#include "cql3/column_identifier.hh"
#include "cql3/CqlParser.hpp"
#include "cql3/error_collector.hh"
#include "cql3/statements/raw/select_statement.hh"
namespace cql3 {
namespace util {
void do_with_parser_impl(const sstring_view& cql, noncopyable_function<void (cql3_parser::CqlParser& p)> func);
template <typename Func, typename Result = cql3_parser::unwrap_uninitialized_t<std::result_of_t<Func(cql3_parser::CqlParser&)>>>
Result do_with_parser(const sstring_view& cql, Func&& f) {
std::optional<Result> ret;
do_with_parser_impl(cql, [&] (cql3_parser::CqlParser& parser) {
ret.emplace(f(parser));
});
return std::move(*ret);
}
sstring relations_to_where_clause(const expr::expression& e);
expr::expression where_clause_to_relations(const sstring_view& where_clause);
sstring rename_column_in_where_clause(const sstring_view& where_clause, column_identifier::raw from, column_identifier::raw to);
/// build a CQL "select" statement with the desired parameters.
/// If select_all_columns==true, all columns are selected and the value of
/// selected_columns is ignored.
std::unique_ptr<cql3::statements::raw::select_statement> build_select_statement(
const sstring_view& cf_name,
const sstring_view& where_clause,
bool select_all_columns,
const std::vector<column_definition>& selected_columns);
/// maybe_quote() takes an identifier - the name of a column, table or
/// keyspace name - and transforms it to a string which can be used in CQL
/// commands. Namely, if the identifier is not entirely lower-case (including
/// digits and underscores), it needs to be quoted to be represented in CQL.
/// Without this quoting, CQL folds uppercase letters to lower case, and
/// forbids non-alpha-numeric characters in identifier names.
/// Quoting involves wrapping the string in double-quotes ("). A double-quote
/// character itself is quoted by doubling it.
/// maybe_quote() also quotes reserved CQL keywords (e.g., "to", "where")
/// but doesn't quote *unreserved* keywords (like ttl, int or as).
/// Note that this means that if new reserved keywords are added to the
/// parser, a saved output of maybe_quote() may no longer be parsable by
/// parser. To avoid this forward-compatibility issue, use quote() instead
/// of maybe_quote() - to unconditionally quote an identifier even if it is
/// lowercase and not (yet) a keyword.
sstring maybe_quote(const sstring& s);
/// quote() takes an identifier - the name of a column, table or keyspace -
/// and transforms it to a string which can be safely used in CQL commands.
/// Quoting involves wrapping the name in double-quotes ("). A double-quote
/// character itself is quoted by doubling it.
/// Quoting is necessary when the identifier contains non-alpha-numeric
/// characters, when it contains uppercase letters (which will be folded to
/// lowercase if not quoted), or when the identifier is one of many CQL
/// keywords. But it's allowed - and easier - to just unconditionally
/// quote the identifier name in CQL, so that is what this function does does.
sstring quote(const sstring& s);
/// single_quote() takes a string and transforms it to a string
/// which can be safely used in CQL commands.
/// Single quoting involves wrapping the name in single-quotes ('). A sigle-quote
/// character itself is quoted by doubling it.
/// Single quoting is necessary for dates, IP addresses or string literals.
sstring single_quote(const sstring& s);
// Check whether timestamp is not too far in the future as this probably
// indicates its incorrectness (for example using other units than microseconds).
void validate_timestamp(const db::config& config, const query_options& options, const std::unique_ptr<attributes>& attrs);
} // namespace util
} // namespace cql3