Files
scylladb/cdc/split.hh
Avi Kivity fcb8d040e8 treewide: use Software Package Data Exchange (SPDX) license identifiers
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.

Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.

The changes we applied mechanically with a script, except to
licenses/README.md.

Closes #9937
2022-01-18 12:15:18 +01:00

81 lines
3.8 KiB
C++

/*
* Copyright (C) 2020-present ScyllaDB
*/
/*
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
#pragma once
#include <vector>
#include <boost/dynamic_bitset.hpp>
#include "schema_fwd.hh"
#include "replica/database_fwd.hh"
#include "timestamp.hh"
#include "bytes.hh"
#include <seastar/util/noncopyable_function.hh>
class mutation;
namespace cdc {
// Represents a set of column ids of one kind (partition key, clustering key, regular row or static row).
// There already exists a column_set type, but it keeps ordinal_column_ids, not column_ids (ordinal column ids
// are unique across whole table, while kind-specific ids are unique only within one column kind).
// To avoid converting back and forth between ordinal and kind-specific ids, one_kind_column_set is used instead.
using one_kind_column_set = boost::dynamic_bitset<uint64_t>;
// An object that processes changes from a single, big mutation.
// It is intended to be used with process_changes_xxx_splitting. Those functions define the order and layout in which
// changes should appear in CDC log, and change_processor is responsible for producing CDC log rows from changes given
// by those two functions.
//
// The flow of calling its methods should go as follows:
// -> begin_timestamp #1
// -> produce_preimage (one call for each preimage row to be generated)
// -> process_change (one call for each part generated by the splitting function)
// -> produce_postimage (one call for each postimage row to be generated)
// -> begin_timestamp #2
// ...
class change_processor {
protected:
~change_processor() {};
public:
// Tells the processor that changes that follow from now on will be of given timestamp.
// This method must be called in increasing timestamp order.
// begin_timestamp can be called only once for a given timestamp and change_processor object.
// ts - timestamp of mutation parts
// is_last - determines if this will be the last timestamp to be processed by this change_processor instance.
virtual void begin_timestamp(api::timestamp_type ts, bool is_last) = 0;
// Tells the processor to produce a preimage for a given clustering/static row.
// ck - clustering key of the row for which to produce a preimage; if nullptr, static row preimage is requested
// columns_to_include - include information about the current state of those columns only, leave others as null
virtual void produce_preimage(const clustering_key* ck, const one_kind_column_set& columns_to_include) = 0;
// Tells the processor to produce a postimage for a given clustering/static row.
// Contrary to preimage, this requires data from all columns to be present.
// ck - clustering key of the row for which to produce a postimage; if nullptr, static row postimage is requested
virtual void produce_postimage(const clustering_key* ck) = 0;
// Processes a smaller mutation which is a subset of the big mutation.
// The mutation provided to process_change should be simple enough for it to be possible to convert it
// into CDC log rows - for example, it cannot represent a write to two columns of the same row, where
// both columns have different timestamp or TTL set.
// m - the small mutation to be converted into CDC log rows.
virtual void process_change(const mutation& m) = 0;
// Tells processor we have reached end of record - last part
// of a given timestamp batch
virtual void end_record() = 0;
};
bool should_split(const mutation& base_mutation);
void process_changes_with_splitting(const mutation& base_mutation, change_processor& processor,
bool enable_preimage, bool enable_postimage);
void process_changes_without_splitting(const mutation& base_mutation, change_processor& processor,
bool enable_preimage, bool enable_postimage);
}