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scylladb/cql3/prepare_context.hh
Avi Kivity 5937b1fa23 treewide: remove empty comments in top-of-files
After fcb8d040 ("treewide: use Software Package Data Exchange
(SPDX) license identifiers"), many dual-licensed files were
left with empty comments on top. Remove them to avoid visual
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Closes #10562
2022-05-13 07:11:58 +02:00

84 lines
2.6 KiB
C++

/*
* Copyright (C) 2015-present ScyllaDB
*
* Modified by ScyllaDB
*/
/*
* SPDX-License-Identifier: (AGPL-3.0-or-later and Apache-2.0)
*/
#pragma once
#include <seastar/core/shared_ptr.hh>
#include "seastarx.hh"
#include <optional>
#include <vector>
#include <stddef.h>
#include "cql3/expr/expression.hh"
class schema;
namespace cql3 {
class column_identifier;
class column_specification;
namespace functions { class function_call; }
/**
* Metadata class currently holding bind variables specifications and
* `function_call` AST nodes inside a query partition key restrictions.
* Populated and maintained at "prepare" step of query execution.
*/
class prepare_context final {
private:
std::vector<shared_ptr<column_identifier>> _variable_names;
std::vector<lw_shared_ptr<column_specification>> _specs;
std::vector<lw_shared_ptr<column_specification>> _target_columns;
// A list of pointers to prepared `function_call` cache ids, that
// participate in partition key ranges computation within an LWT statement.
std::vector<::shared_ptr<std::optional<uint8_t>>> _pk_function_calls_cache_ids;
// The flag denoting whether the context is currently in partition key
// processing mode (inside query restrictions AST nodes). If set to true,
// then every `function_call` instance will be recorded in the context and
// will be assigned an identifier, which will then be used for caching
// the function call results.
bool _processing_pk_restrictions = false;
public:
prepare_context() = default;
size_t bound_variables_size() const;
const std::vector<lw_shared_ptr<column_specification>>& get_variable_specifications() const &;
std::vector<lw_shared_ptr<column_specification>> get_variable_specifications() &&;
std::vector<uint16_t> get_partition_key_bind_indexes(const schema& schema) const;
void add_variable_specification(int32_t bind_index, lw_shared_ptr<column_specification> spec);
void set_bound_variables(const std::vector<shared_ptr<column_identifier>>& prepare_meta);
void clear_pk_function_calls_cache();
// Record a new function call, which evaluates a partition key constraint.
// Also automatically assigns an id to the AST node for caching purposes.
void add_pk_function_call(cql3::expr::function_call& fn);
// Inform the context object that it has started or ended processing the
// partition key part of statement restrictions.
void set_processing_pk_restrictions(bool flag) noexcept {
_processing_pk_restrictions = flag;
}
bool is_processing_pk_restrictions() const noexcept {
return _processing_pk_restrictions;
}
};
}