Files
scylladb/mutation_partition.hh
2015-07-15 18:56:10 +02:00

351 lines
14 KiB
C++

/*
* Copyright (C) 2014 Cloudius Systems, Ltd.
*/
#pragma once
#include <iostream>
#include <map>
#include <boost/intrusive/set.hpp>
#include <boost/range/iterator_range.hpp>
#include "schema.hh"
#include "keys.hh"
#include "atomic_cell.hh"
#include "query-result-writer.hh"
#include "mutation_partition_view.hh"
// Container for cells of a row. Cells are identified by column_id.
//
// Can be used as a range of std::pair<column_id, atomic_cell_or_collection>.
//
class row {
using map_type = std::map<column_id, atomic_cell_or_collection>;
map_type _cells;
public:
using value_type = map_type::value_type;
using iterator = map_type::iterator;
using const_iterator = map_type::const_iterator;
public:
iterator begin() { return _cells.begin(); }
iterator end() { return _cells.end(); }
const_iterator begin() const { return _cells.begin(); }
const_iterator end() const { return _cells.end(); }
size_t size() const { return _cells.size(); }
// Returns a reference to cell's value or throws std::out_of_range
const atomic_cell_or_collection& cell_at(column_id id) const { return _cells.at(id); }
// Returns a pointer to cell's value or nullptr if column is not set.
const atomic_cell_or_collection* find_cell(column_id id) const;
public:
// Merges cell's value into the row.
void apply(const column_definition& column, atomic_cell_or_collection cell);
// Adds cell to the row. The column must not be already set.
void append_cell(column_id id, atomic_cell_or_collection cell);
// Merges given cell into the row.
template <typename ColumnDefinitionResolver>
void apply(column_id id, atomic_cell_or_collection cell, ColumnDefinitionResolver&& resolver) {
auto i = _cells.lower_bound(id);
if (i == _cells.end() || i->first != id) {
_cells.emplace_hint(i, id, std::move(cell));
} else {
merge_column(resolver(id), i->second, std::move(cell));
}
}
// Expires cells based on query_time. Removes cells covered by tomb.
// Returns true iff there are any live cells left.
template <typename ColumnDefinitionResolver>
bool compact_and_expire(tombstone tomb, gc_clock::time_point query_time, ColumnDefinitionResolver&& resolver) {
bool any_live = false;
for (auto it = _cells.begin(); it != _cells.end(); ) {
auto& entry = *it;
bool erase = false;
const column_definition& def = resolver(entry.first);
if (def.is_atomic()) {
atomic_cell_view cell = entry.second.as_atomic_cell();
if (cell.is_covered_by(tomb)) {
erase = true;
} else if (cell.has_expired(query_time)) {
entry.second = atomic_cell::make_dead(cell.timestamp(), cell.deletion_time());
} else {
any_live |= cell.is_live();
}
} else {
auto&& cell = entry.second.as_collection_mutation();
auto&& ctype = static_pointer_cast<const collection_type_impl>(def.type);
auto m_view = ctype->deserialize_mutation_form(cell);
collection_type_impl::mutation m = m_view.materialize();
any_live |= m.compact_and_expire(tomb, query_time);
if (m.cells.empty() && m.tomb <= tomb) {
erase = true;
} else {
entry.second = ctype->serialize_mutation_form(m);
}
}
if (erase) {
it = _cells.erase(it);
} else {
++it;
}
}
return any_live;
}
};
std::ostream& operator<<(std::ostream& os, const row::value_type& rv);
std::ostream& operator<<(std::ostream& os, const row& r);
class deletable_row final {
tombstone _deleted_at;
api::timestamp_type _created_at = api::missing_timestamp;
row _cells;
public:
deletable_row() {}
void apply(tombstone deleted_at) {
_deleted_at.apply(deleted_at);
}
void apply(api::timestamp_type created_at) {
_created_at = std::max(_created_at, created_at);
}
public:
tombstone deleted_at() const { return _deleted_at; }
api::timestamp_type created_at() const { return _created_at; }
const row& cells() const { return _cells; }
row& cells() { return _cells; }
friend std::ostream& operator<<(std::ostream& os, const deletable_row& dr);
bool equal(const schema& s, const deletable_row& other) const;
bool is_live(const schema& s, tombstone base_tombstone, gc_clock::time_point query_time) const;
};
class row_tombstones_entry : public boost::intrusive::set_base_hook<> {
clustering_key_prefix _prefix;
tombstone _t;
public:
row_tombstones_entry(clustering_key_prefix&& prefix, tombstone t)
: _prefix(std::move(prefix))
, _t(std::move(t))
{ }
clustering_key_prefix& prefix() {
return _prefix;
}
const clustering_key_prefix& prefix() const {
return _prefix;
}
tombstone& t() {
return _t;
}
const tombstone& t() const {
return _t;
}
void apply(tombstone t) {
_t.apply(t);
}
struct compare {
clustering_key_prefix::less_compare _c;
compare(const schema& s) : _c(s) {}
bool operator()(const row_tombstones_entry& e1, const row_tombstones_entry& e2) const {
return _c(e1._prefix, e2._prefix);
}
bool operator()(const clustering_key_prefix& prefix, const row_tombstones_entry& e) const {
return _c(prefix, e._prefix);
}
bool operator()(const row_tombstones_entry& e, const clustering_key_prefix& prefix) const {
return _c(e._prefix, prefix);
}
};
template <typename Comparator>
struct delegating_compare {
Comparator _c;
delegating_compare(Comparator&& c) : _c(std::move(c)) {}
template <typename Comparable>
bool operator()(const Comparable& prefix, const row_tombstones_entry& e) const {
return _c(prefix, e._prefix);
}
template <typename Comparable>
bool operator()(const row_tombstones_entry& e, const Comparable& prefix) const {
return _c(e._prefix, prefix);
}
};
template <typename Comparator>
static auto key_comparator(Comparator&& c) {
return delegating_compare<Comparator>(std::move(c));
}
friend std::ostream& operator<<(std::ostream& os, const row_tombstones_entry& rte);
bool equal(const schema& s, const row_tombstones_entry& other) const;
};
class rows_entry : public boost::intrusive::set_base_hook<> {
clustering_key _key;
deletable_row _row;
public:
rows_entry(clustering_key&& key)
: _key(std::move(key))
{ }
rows_entry(const clustering_key& key)
: _key(key)
{ }
rows_entry(const rows_entry& e)
: _key(e._key)
, _row(e._row)
{ }
clustering_key& key() {
return _key;
}
const clustering_key& key() const {
return _key;
}
deletable_row& row() {
return _row;
}
const deletable_row& row() const {
return _row;
}
void apply(tombstone t) {
_row.apply(t);
}
struct compare {
clustering_key::less_compare _c;
compare(const schema& s) : _c(s) {}
bool operator()(const rows_entry& e1, const rows_entry& e2) const {
return _c(e1._key, e2._key);
}
bool operator()(const clustering_key& key, const rows_entry& e) const {
return _c(key, e._key);
}
bool operator()(const rows_entry& e, const clustering_key& key) const {
return _c(e._key, key);
}
bool operator()(const clustering_key_view& key, const rows_entry& e) const {
return _c(key, e._key);
}
bool operator()(const rows_entry& e, const clustering_key_view& key) const {
return _c(e._key, key);
}
};
template <typename Comparator>
struct delegating_compare {
Comparator _c;
delegating_compare(Comparator&& c) : _c(std::move(c)) {}
template <typename Comparable>
bool operator()(const Comparable& v, const rows_entry& e) const {
return _c(v, e._key);
}
template <typename Comparable>
bool operator()(const rows_entry& e, const Comparable& v) const {
return _c(e._key, v);
}
};
template <typename Comparator>
static auto key_comparator(Comparator&& c) {
return delegating_compare<Comparator>(std::move(c));
}
friend std::ostream& operator<<(std::ostream& os, const rows_entry& re);
bool equal(const schema& s, const rows_entry& other) const;
};
namespace db {
template<typename T>
class serializer;
}
class mutation_partition final {
// FIXME: using boost::intrusive because gcc's std::set<> does not support heterogeneous lookup yet
using rows_type = boost::intrusive::set<rows_entry, boost::intrusive::compare<rows_entry::compare>>;
using row_tombstones_type = boost::intrusive::set<row_tombstones_entry, boost::intrusive::compare<row_tombstones_entry::compare>>;
private:
tombstone _tombstone;
row _static_row;
rows_type _rows;
// Contains only strict prefixes so that we don't have to lookup full keys
// in both _row_tombstones and _rows.
// FIXME: using boost::intrusive because gcc's std::set<> does not support heterogeneous lookup yet
row_tombstones_type _row_tombstones;
template<typename T>
friend class db::serializer;
friend class mutation_partition_applier;
public:
mutation_partition(schema_ptr s)
: _rows(rows_entry::compare(*s))
, _row_tombstones(row_tombstones_entry::compare(*s))
{ }
mutation_partition(mutation_partition&&) = default;
mutation_partition(const mutation_partition&);
~mutation_partition();
mutation_partition& operator=(const mutation_partition& x);
mutation_partition& operator=(mutation_partition&& x) = default;
bool equal(const schema& s, const mutation_partition&) const;
friend std::ostream& operator<<(std::ostream& os, const mutation_partition& mp);
public:
void apply(tombstone t) { _tombstone.apply(t); }
void apply_delete(const schema& schema, const exploded_clustering_prefix& prefix, tombstone t);
void apply_delete(const schema& schema, clustering_key&& key, tombstone t);
void apply_delete(const schema& schema, clustering_key_view key, tombstone t);
// Equivalent to applying a mutation with an empty row, created with given timestamp
void apply_insert(const schema& s, clustering_key_view, api::timestamp_type created_at);
// prefix must not be full
void apply_row_tombstone(const schema& schema, clustering_key_prefix prefix, tombstone t);
void apply(const schema& schema, const mutation_partition& p);
void apply(const schema& schema, mutation_partition_view);
public:
// Performs the following:
// - throws out data which doesn't belong to row_ranges
// - expires cells based on query_time
// - drops cells covered by higher-level tombstones (compaction)
// - leaves at most row_limit live rows
//
// FIXME: Should also perform tombstone GC.
//
// Note: a partition with a static row which has any cell live but no
// clustered rows still counts as one row, according to the CQL row
// counting rules.
//
// Returns the count of CQL rows which remained. If the returned number is
// smaller than the row_limit it means that there was no more data
// satisfying the query left.
//
// The row_limit parameter must be > 0.
//
uint32_t compact_for_query(const schema& s, gc_clock::time_point query_time,
const std::vector<query::clustering_range>& row_ranges, uint32_t row_limit);
public:
deletable_row& clustered_row(const clustering_key& key);
deletable_row& clustered_row(clustering_key&& key);
deletable_row& clustered_row(const schema& s, const clustering_key_view& key);
public:
tombstone partition_tombstone() const { return _tombstone; }
row& static_row() { return _static_row; }
const row& static_row() const { return _static_row; }
// return a set of rows_entry where each entry represents a CQL row sharing the same clustering key.
const rows_type& clustered_rows() const { return _rows; }
const row_tombstones_type& row_tombstones() const { return _row_tombstones; }
const row* find_row(const clustering_key& key) const;
const rows_entry* find_entry(const schema& schema, const clustering_key_prefix& key) const;
tombstone range_tombstone_for_row(const schema& schema, const clustering_key& key) const;
tombstone tombstone_for_row(const schema& schema, const clustering_key& key) const;
tombstone tombstone_for_row(const schema& schema, const rows_entry& e) const;
boost::iterator_range<rows_type::const_iterator> range(const schema& schema, const query::range<clustering_key_prefix>& r) const;
// Returns at most "limit" rows. The limit must be greater than 0.
void query(query::result::partition_writer& pw, const schema& s, gc_clock::time_point now, uint32_t limit = query::max_rows) const;
// Returns the number of live CQL rows in this partition.
//
// Note: If no regular rows are live, but there's something live in the
// static row, the static row counts as one row. If there is at least one
// regular row live, static row doesn't count.
//
size_t live_row_count(const schema&,
gc_clock::time_point query_time = gc_clock::time_point::min()) const;
bool is_static_row_live(const schema&,
gc_clock::time_point query_time = gc_clock::time_point::min()) const;
};