mirrors/scylladb
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
cd80d6ff656d51f563cb6524386a65ff67b36619
scylladb/flat_mutation_reader.cc
Botond Dénes eb357a385d flat_mutation_reader: make timeout opt-out rather than opt-in 
Currently timeout is opt-in, that is, all methods that even have it
default it to `db::no_timeout`. This means that ensuring timeout is used
where it should be is completely up to the author and the reviewrs of
the code. As humans are notoriously prone to mistakes this has resulted
in a very inconsistent usage of timeout, many clients of
`flat_mutation_reader` passing the timeout only to some members and only
on certain call sites. This is small wonder considering that some core
operations like `operator()()` only recently received a timeout
parameter and others like `peek()` didn't even have one until this
patch. Both of these methods call `fill_buffer()` which potentially
talks to the lower layers and is supposed to propagate the timeout.
All this makes the `flat_mutation_reader`'s timeout effectively useless.

To make order in this chaos make the timeout parameter a mandatory one
on all `flat_mutation_reader` methods that need it. This ensures that
humans now get a reminder from the compiler when they forget to pass the
timeout. Clients can still opt-out from passing a timeout by passing
`db::no_timeout` (the previous default value) but this will be now
explicit and developers should think before typing it.

There were suprisingly few core call sites to fix up. Where a timeout
was available nearby I propagated it to be able to pass it to the
reader, where I couldn't I passed `db::no_timeout`. Authors of the
latter kind of code (view, streaming and repair are some of the notable
examples) should maybe consider propagating down a timeout if needed.
In the test code (the wast majority of the changes) I just used
`db::no_timeout` everywhere.

Tests: unit(release, debug)

Signed-off-by: Botond Dénes <bdenes@scylladb.com>

Message-Id: <1edc10802d5eb23de8af28c9f48b8d3be0f1a468.1536744563.git.bdenes@scylladb.com>
2018-09-20 11:31:24 +02:00

674 lines
28 KiB
C++
Raw Blame History

/*
* Copyright (C) 2017 ScyllaDB
*/
/*
* This file is part of Scylla.
*
* Scylla is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Scylla is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
*/
#include "flat_mutation_reader.hh"
#include "mutation_reader.hh"
#include "seastar/util/reference_wrapper.hh"
#include <algorithm>
#include <boost/range/adaptor/transformed.hpp>
#include <seastar/util/defer.hh>
static size_t compute_buffer_size(const schema& s, circular_buffer<mutation_fragment>& buffer)
{
return boost::accumulate(
buffer
| boost::adaptors::transformed([&s] (const mutation_fragment& mf) {
return mf.memory_usage(s);
}), size_t(0)
);
}
void flat_mutation_reader::impl::forward_buffer_to(const position_in_partition& pos) {
_buffer.erase(std::remove_if(_buffer.begin(), _buffer.end(), [this, &pos] (mutation_fragment& f) {
return !f.relevant_for_range_assuming_after(*_schema, pos);
}), _buffer.end());
_buffer_size = compute_buffer_size(*_schema, _buffer);
}
void flat_mutation_reader::impl::clear_buffer_to_next_partition() {
auto next_partition_start = std::find_if(_buffer.begin(), _buffer.end(), [] (const mutation_fragment& mf) {
return mf.is_partition_start();
});
_buffer.erase(_buffer.begin(), next_partition_start);
_buffer_size = compute_buffer_size(*_schema, _buffer);
}
flat_mutation_reader flat_mutation_reader::impl::reverse_partitions(flat_mutation_reader::impl& original) {
// FIXME: #1413 Full partitions get accumulated in memory.
class partition_reversing_mutation_reader final : public flat_mutation_reader::impl {
flat_mutation_reader::impl* _source;
range_tombstone_list _range_tombstones;
std::stack<mutation_fragment> _mutation_fragments;
mutation_fragment_opt _partition_end;
private:
stop_iteration emit_partition() {
auto emit_range_tombstone = [&] {
auto it = std::prev(_range_tombstones.tombstones().end());
auto& rt = *it;
_range_tombstones.tombstones().erase(it);
auto rt_owner = alloc_strategy_unique_ptr<range_tombstone>(&rt);
push_mutation_fragment(mutation_fragment(std::move(rt)));
};
position_in_partition::less_compare cmp(*_source->_schema);
while (!_mutation_fragments.empty() && !is_buffer_full()) {
auto& mf = _mutation_fragments.top();
if (!_range_tombstones.empty() && !cmp(_range_tombstones.tombstones().rbegin()->end_position(), mf.position())) {
emit_range_tombstone();
} else {
push_mutation_fragment(std::move(mf));
_mutation_fragments.pop();
}
}
while (!_range_tombstones.empty() && !is_buffer_full()) {
emit_range_tombstone();
}
if (is_buffer_full()) {
return stop_iteration::yes;
}
push_mutation_fragment(std::move(*std::exchange(_partition_end, stdx::nullopt)));
return stop_iteration::no;
}
future<stop_iteration> consume_partition_from_source(db::timeout_clock::time_point timeout) {
if (_source->is_buffer_empty()) {
if (_source->is_end_of_stream()) {
_end_of_stream = true;
return make_ready_future<stop_iteration>(stop_iteration::yes);
}
return _source->fill_buffer(timeout).then([] { return stop_iteration::no; });
}
while (!_source->is_buffer_empty() && !is_buffer_full()) {
auto mf = _source->pop_mutation_fragment();
if (mf.is_partition_start() || mf.is_static_row()) {
push_mutation_fragment(std::move(mf));
} else if (mf.is_end_of_partition()) {
_partition_end = std::move(mf);
if (emit_partition()) {
return make_ready_future<stop_iteration>(stop_iteration::yes);
}
} else if (mf.is_range_tombstone()) {
_range_tombstones.apply(*_source->_schema, std::move(mf.as_range_tombstone()));
} else {
_mutation_fragments.emplace(std::move(mf));
}
}
return make_ready_future<stop_iteration>(is_buffer_full());
}
public:
explicit partition_reversing_mutation_reader(flat_mutation_reader::impl& mr)
: flat_mutation_reader::impl(mr._schema)
, _source(&mr)
, _range_tombstones(*mr._schema)
{ }
virtual future<> fill_buffer(db::timeout_clock::time_point timeout) override {
return repeat([&, timeout] {
if (_partition_end) {
// We have consumed full partition from source, now it is
// time to emit it.
auto stop = emit_partition();
if (stop) {
return make_ready_future<stop_iteration>(stop_iteration::yes);
}
}
return consume_partition_from_source(timeout);
});
}
virtual void next_partition() override {
clear_buffer_to_next_partition();
if (is_buffer_empty() && !is_end_of_stream()) {
while (!_mutation_fragments.empty()) {
_mutation_fragments.pop();
}
_range_tombstones.clear();
_partition_end = stdx::nullopt;
_source->next_partition();
}
}
virtual future<> fast_forward_to(const dht::partition_range&, db::timeout_clock::time_point) override {
throw std::bad_function_call();
}
virtual future<> fast_forward_to(position_range, db::timeout_clock::time_point) override {
throw std::bad_function_call();
}
virtual size_t buffer_size() const override {
return flat_mutation_reader::impl::buffer_size() + _source->buffer_size();
}
};
return make_flat_mutation_reader<partition_reversing_mutation_reader>(original);
}
template<typename Source>
future<bool> flat_mutation_reader::impl::fill_buffer_from(Source& source, db::timeout_clock::time_point timeout) {
if (source.is_buffer_empty()) {
if (source.is_end_of_stream()) {
return make_ready_future<bool>(true);
}
return source.fill_buffer(timeout).then([this, &source, timeout] {
return fill_buffer_from(source, timeout);
});
} else {
while (!source.is_buffer_empty() && !is_buffer_full()) {
push_mutation_fragment(source.pop_mutation_fragment());
}
return make_ready_future<bool>(source.is_end_of_stream() && source.is_buffer_empty());
}
}
template future<bool> flat_mutation_reader::impl::fill_buffer_from<flat_mutation_reader>(flat_mutation_reader&, db::timeout_clock::time_point);
flat_mutation_reader& to_reference(reference_wrapper<flat_mutation_reader>& wrapper) {
return wrapper.get();
}
flat_mutation_reader make_delegating_reader(flat_mutation_reader& r) {
return make_flat_mutation_reader<delegating_reader<reference_wrapper<flat_mutation_reader>>>(ref(r));
}
flat_mutation_reader make_forwardable(flat_mutation_reader m) {
class reader : public flat_mutation_reader::impl {
flat_mutation_reader _underlying;
position_range _current;
mutation_fragment_opt _next;
// When resolves, _next is engaged or _end_of_stream is set.
future<> ensure_next(db::timeout_clock::time_point timeout) {
if (_next) {
return make_ready_future<>();
}
return _underlying(timeout).then([this] (auto&& mfo) {
_next = std::move(mfo);
if (!_next) {
_end_of_stream = true;
}
});
}
public:
reader(flat_mutation_reader r) : impl(r.schema()), _underlying(std::move(r)), _current({
position_in_partition(position_in_partition::partition_start_tag_t()),
position_in_partition(position_in_partition::after_static_row_tag_t())
}) { }
virtual future<> fill_buffer(db::timeout_clock::time_point timeout) override {
return repeat([this, timeout] {
if (is_buffer_full()) {
return make_ready_future<stop_iteration>(stop_iteration::yes);
}
return ensure_next(timeout).then([this] {
if (is_end_of_stream()) {
return stop_iteration::yes;
}
position_in_partition::less_compare cmp(*_schema);
if (!cmp(_next->position(), _current.end())) {
_end_of_stream = true;
// keep _next, it may be relevant for next range
return stop_iteration::yes;
}
if (_next->relevant_for_range(*_schema, _current.start())) {
push_mutation_fragment(std::move(*_next));
}
_next = {};
return stop_iteration::no;
});
});
}
virtual future<> fast_forward_to(position_range pr, db::timeout_clock::time_point timeout) override {
_current = std::move(pr);
_end_of_stream = false;
forward_buffer_to(_current.start());
return make_ready_future<>();
}
virtual void next_partition() override {
_end_of_stream = false;
if (!_next || !_next->is_partition_start()) {
_underlying.next_partition();
_next = {};
}
clear_buffer_to_next_partition();
_current = {
position_in_partition(position_in_partition::partition_start_tag_t()),
position_in_partition(position_in_partition::after_static_row_tag_t())
};
}
virtual future<> fast_forward_to(const dht::partition_range& pr, db::timeout_clock::time_point timeout) override {
_end_of_stream = false;
clear_buffer();
_next = {};
_current = {
position_in_partition(position_in_partition::partition_start_tag_t()),
position_in_partition(position_in_partition::after_static_row_tag_t())
};
return _underlying.fast_forward_to(pr, timeout);
}
virtual size_t buffer_size() const override {
return flat_mutation_reader::impl::buffer_size() + _underlying.buffer_size();
}
};
return make_flat_mutation_reader<reader>(std::move(m));
}
flat_mutation_reader make_nonforwardable(flat_mutation_reader r, bool single_partition) {
class reader : public flat_mutation_reader::impl {
flat_mutation_reader _underlying;
bool _single_partition;
bool _static_row_done = false;
bool is_end_end_of_underlying_stream() const {
return _underlying.is_buffer_empty() && _underlying.is_end_of_stream();
}
future<> on_end_of_underlying_stream(db::timeout_clock::time_point timeout) {
if (!_static_row_done) {
_static_row_done = true;
return _underlying.fast_forward_to(position_range::all_clustered_rows(), timeout);
}
push_mutation_fragment(partition_end());
if (_single_partition) {
_end_of_stream = true;
return make_ready_future<>();
}
_underlying.next_partition();
_static_row_done = false;
return _underlying.fill_buffer(timeout).then([this] {
_end_of_stream = is_end_end_of_underlying_stream();
});
}
public:
reader(flat_mutation_reader r, bool single_partition)
: impl(r.schema())
, _underlying(std::move(r))
, _single_partition(single_partition)
{ }
virtual future<> fill_buffer(db::timeout_clock::time_point timeout) override {
return do_until([this] { return is_end_of_stream() || is_buffer_full(); }, [this, timeout] {
return fill_buffer_from(_underlying, timeout).then([this, timeout] (bool underlying_finished) {
if (underlying_finished) {
return on_end_of_underlying_stream(timeout);
}
return make_ready_future<>();
});
});
}
virtual future<> fast_forward_to(position_range pr, db::timeout_clock::time_point timeout) override {
throw std::bad_function_call();
}
virtual void next_partition() override {
clear_buffer_to_next_partition();
if (is_buffer_empty()) {
_underlying.next_partition();
}
_end_of_stream = is_end_end_of_underlying_stream();
}
virtual future<> fast_forward_to(const dht::partition_range& pr, db::timeout_clock::time_point timeout) override {
_end_of_stream = false;
clear_buffer();
return _underlying.fast_forward_to(pr, timeout);
}
virtual size_t buffer_size() const override {
return flat_mutation_reader::impl::buffer_size() + _underlying.buffer_size();
}
};
return make_flat_mutation_reader<reader>(std::move(r), single_partition);
}
class empty_flat_reader final : public flat_mutation_reader::impl {
public:
empty_flat_reader(schema_ptr s) : impl(std::move(s)) { _end_of_stream = true; }
virtual future<> fill_buffer(db::timeout_clock::time_point timeout) override { return make_ready_future<>(); }
virtual void next_partition() override {}
virtual future<> fast_forward_to(const dht::partition_range& pr, db::timeout_clock::time_point timeout) override { return make_ready_future<>(); };
virtual future<> fast_forward_to(position_range cr, db::timeout_clock::time_point timeout) override { return make_ready_future<>(); };
};
flat_mutation_reader make_empty_flat_reader(schema_ptr s) {
return make_flat_mutation_reader<empty_flat_reader>(std::move(s));
}
flat_mutation_reader
flat_mutation_reader_from_mutations(std::vector<mutation> ms,
const query::partition_slice& slice,
streamed_mutation::forwarding fwd) {
std::vector<mutation> sliced_ms;
for (auto& m : ms) {
auto ck_ranges = query::clustering_key_filter_ranges::get_ranges(*m.schema(), slice, m.key());
auto mp = mutation_partition(std::move(m.partition()), *m.schema(), std::move(ck_ranges));
sliced_ms.emplace_back(m.schema(), m.decorated_key(), std::move(mp));
}
return flat_mutation_reader_from_mutations(sliced_ms, query::full_partition_range, fwd);
}
flat_mutation_reader
flat_mutation_reader_from_mutations(std::vector<mutation> mutations, const dht::partition_range& pr, streamed_mutation::forwarding fwd) {
class reader final : public flat_mutation_reader::impl {
std::vector<mutation> _mutations;
std::vector<mutation>::iterator _cur;
std::vector<mutation>::iterator _end;
position_in_partition::less_compare _cmp;
bool _static_row_done = false;
mutation_fragment_opt _rt;
mutation_fragment_opt _cr;
private:
void prepare_next_clustering_row() {
auto& crs = _cur->partition().clustered_rows();
while (true) {
auto re = crs.unlink_leftmost_without_rebalance();
if (!re) {
break;
}
auto re_deleter = defer([re] { current_deleter<rows_entry>()(re); });
if (!re->dummy()) {
_cr = mutation_fragment(std::move(*re));
break;
}
}
}
void prepare_next_range_tombstone() {
auto& rts = _cur->partition().row_tombstones().tombstones();
auto rt = rts.unlink_leftmost_without_rebalance();
if (rt) {
auto rt_deleter = defer([rt] { current_deleter<range_tombstone>()(rt); });
_rt = mutation_fragment(std::move(*rt));
}
}
mutation_fragment_opt read_next() {
if (_cr && (!_rt || _cmp(_cr->position(), _rt->position()))) {
auto cr = std::exchange(_cr, { });
prepare_next_clustering_row();
return cr;
} else if (_rt) {
auto rt = std::exchange(_rt, { });
prepare_next_range_tombstone();
return rt;
}
return { };
}
private:
void do_fill_buffer(db::timeout_clock::time_point timeout) {
while (!is_end_of_stream() && !is_buffer_full()) {
if (!_static_row_done) {
_static_row_done = true;
if (!_cur->partition().static_row().empty()) {
push_mutation_fragment(static_row(std::move(_cur->partition().static_row())));
}
}
auto mfopt = read_next();
if (mfopt) {
push_mutation_fragment(std::move(*mfopt));
} else {
push_mutation_fragment(partition_end());
++_cur;
if (_cur == _end) {
_end_of_stream = true;
} else {
start_new_partition();
}
}
}
}
void start_new_partition() {
_static_row_done = false;
push_mutation_fragment(partition_start(_cur->decorated_key(),
_cur->partition().partition_tombstone()));
prepare_next_clustering_row();
prepare_next_range_tombstone();
}
void destroy_current_mutation() {
auto &crs = _cur->partition().clustered_rows();
auto re = crs.unlink_leftmost_without_rebalance();
while (re) {
current_deleter<rows_entry>()(re);
re = crs.unlink_leftmost_without_rebalance();
}
auto &rts = _cur->partition().row_tombstones().tombstones();
auto rt = rts.unlink_leftmost_without_rebalance();
while (rt) {
current_deleter<range_tombstone>()(rt);
rt = rts.unlink_leftmost_without_rebalance();
}
}
struct cmp {
bool operator()(const mutation& m, const dht::ring_position& p) const {
return m.decorated_key().tri_compare(*m.schema(), p) < 0;
}
bool operator()(const dht::ring_position& p, const mutation& m) const {
return m.decorated_key().tri_compare(*m.schema(), p) > 0;
}
};
static std::vector<mutation>::iterator find_first_partition(std::vector<mutation>& ms, const dht::partition_range& pr) {
if (!pr.start()) {
return std::begin(ms);
}
if (pr.is_singular()) {
return std::lower_bound(std::begin(ms), std::end(ms), pr.start()->value(), cmp{});
} else {
if (pr.start()->is_inclusive()) {
return std::lower_bound(std::begin(ms), std::end(ms), pr.start()->value(), cmp{});
} else {
return std::upper_bound(std::begin(ms), std::end(ms), pr.start()->value(), cmp{});
}
}
}
static std::vector<mutation>::iterator find_last_partition(std::vector<mutation>& ms, const dht::partition_range& pr) {
if (!pr.end()) {
return std::end(ms);
}
if (pr.is_singular()) {
return std::upper_bound(std::begin(ms), std::end(ms), pr.start()->value(), cmp{});
} else {
if (pr.end()->is_inclusive()) {
return std::upper_bound(std::begin(ms), std::end(ms), pr.end()->value(), cmp{});
} else {
return std::lower_bound(std::begin(ms), std::end(ms), pr.end()->value(), cmp{});
}
}
}
public:
reader(schema_ptr s, std::vector<mutation>&& mutations, const dht::partition_range& pr)
: impl(std::move(s))
, _mutations(std::move(mutations))
, _cur(find_first_partition(_mutations, pr))
, _end(find_last_partition(_mutations, pr))
, _cmp(*_cur->schema())
{
_end_of_stream = _cur == _end;
if (!_end_of_stream) {
auto mutation_destroyer = defer([this] { destroy_mutations(); });
start_new_partition();
do_fill_buffer(db::no_timeout);
mutation_destroyer.cancel();
}
}
void destroy_mutations() noexcept {
// After unlink_leftmost_without_rebalance() was called on a bi::set
// we need to complete destroying the tree using that function.
// clear_and_dispose() used by mutation_partition destructor won't
// work properly.
while (_cur != _end) {
destroy_current_mutation();
++_cur;
}
}
~reader() {
destroy_mutations();
}
virtual future<> fill_buffer(db::timeout_clock::time_point timeout) override {
do_fill_buffer(timeout);
return make_ready_future<>();
}
virtual void next_partition() override {
clear_buffer_to_next_partition();
if (is_buffer_empty() && !is_end_of_stream()) {
destroy_current_mutation();
++_cur;
if (_cur == _end) {
_end_of_stream = true;
} else {
start_new_partition();
}
}
}
virtual future<> fast_forward_to(const dht::partition_range& pr, db::timeout_clock::time_point timeout) override {
clear_buffer();
_cur = find_first_partition(_mutations, pr);
_end = find_last_partition(_mutations, pr);
_static_row_done = false;
_cr = {};
_rt = {};
_end_of_stream = _cur == _end;
if (!_end_of_stream) {
start_new_partition();
}
return make_ready_future<>();
};
virtual future<> fast_forward_to(position_range cr, db::timeout_clock::time_point timeout) override {
throw std::runtime_error("This reader can't be fast forwarded to another position.");
};
};
assert(!mutations.empty());
schema_ptr s = mutations[0].schema();
auto res = make_flat_mutation_reader<reader>(std::move(s), std::move(mutations), pr);
if (fwd) {
return make_forwardable(std::move(res));
}
return res;
}
class flat_multi_range_mutation_reader : public flat_mutation_reader::impl {
public:
using ranges_vector = dht::partition_range_vector;
private:
const ranges_vector& _ranges;
ranges_vector::const_iterator _current_range;
flat_mutation_reader _reader;
public:
flat_multi_range_mutation_reader(schema_ptr s, mutation_source source, const ranges_vector& ranges,
const query::partition_slice& slice, const io_priority_class& pc,
tracing::trace_state_ptr trace_state,
mutation_reader::forwarding fwd_mr)
: impl(s)
, _ranges(ranges)
, _current_range(_ranges.begin())
, _reader(source.make_reader(s, *_current_range, slice, pc, trace_state, streamed_mutation::forwarding::no,
_ranges.size() > 1 ? mutation_reader::forwarding::yes : fwd_mr))
{
}
virtual future<> fill_buffer(db::timeout_clock::time_point timeout) override {
return do_until([this] { return is_end_of_stream() || !is_buffer_empty(); }, [this, timeout] {
return _reader.fill_buffer(timeout).then([this, timeout] () {
while (!_reader.is_buffer_empty()) {
push_mutation_fragment(_reader.pop_mutation_fragment());
}
if (!_reader.is_end_of_stream()) {
return make_ready_future<>();
}
++_current_range;
if (_current_range == _ranges.end()) {
_end_of_stream = true;
return make_ready_future<>();
}
return _reader.fast_forward_to(*_current_range, timeout);
});
});
}
virtual future<> fast_forward_to(const dht::partition_range& pr, db::timeout_clock::time_point timeout) override {
clear_buffer();
_end_of_stream = false;
// When end of pr is reached, this reader will increment _current_range
// and notice that it now points to _ranges.end().
_current_range = std::prev(_ranges.end());
return _reader.fast_forward_to(pr, timeout);
}
virtual future<> fast_forward_to(position_range pr, db::timeout_clock::time_point timeout) override {
throw std::bad_function_call();
}
virtual void next_partition() override {
clear_buffer_to_next_partition();
if (is_buffer_empty() && !is_end_of_stream()) {
_reader.next_partition();
}
}
virtual size_t buffer_size() const override {
return flat_mutation_reader::impl::buffer_size() + _reader.buffer_size();
}
};
flat_mutation_reader
make_flat_multi_range_reader(schema_ptr s, mutation_source source, const dht::partition_range_vector& ranges,
const query::partition_slice& slice, const io_priority_class& pc,
tracing::trace_state_ptr trace_state,
mutation_reader::forwarding fwd_mr)
{
if (ranges.empty()) {
return make_empty_flat_reader(std::move(s));
} else if (ranges.size() == 1) {
return source.make_reader(std::move(s), ranges.front(), slice, pc, std::move(trace_state), streamed_mutation::forwarding::no, fwd_mr);
} else {
return make_flat_mutation_reader<flat_multi_range_mutation_reader>(std::move(s), std::move(source), ranges,
slice, pc, std::move(trace_state), fwd_mr);
}
}
flat_mutation_reader
make_flat_mutation_reader_from_fragments(schema_ptr schema, std::deque<mutation_fragment> fragments) {
class reader : public flat_mutation_reader::impl {
std::deque<mutation_fragment> _fragments;
public:
reader(schema_ptr schema, std::deque<mutation_fragment> fragments)
: flat_mutation_reader::impl(std::move(schema))
, _fragments(std::move(fragments)) {
}
virtual future<> fill_buffer(db::timeout_clock::time_point) override {
while (!(_end_of_stream = _fragments.empty()) && !is_buffer_full()) {
push_mutation_fragment(std::move(_fragments.front()));
_fragments.pop_front();
}
return make_ready_future<>();
}
virtual void next_partition() override {
clear_buffer_to_next_partition();
if (is_buffer_empty()) {
while (!(_end_of_stream = _fragments.empty()) && !_fragments.front().is_partition_start()) {
_fragments.pop_front();
}
}
}
virtual future<> fast_forward_to(position_range pr, db::timeout_clock::time_point timeout) override {
throw std::runtime_error("This reader can't be fast forwarded to another range.");
}
virtual future<> fast_forward_to(const dht::partition_range& pr, db::timeout_clock::time_point timeout) override {
throw std::runtime_error("This reader can't be fast forwarded to another position.");
}
};
return make_flat_mutation_reader<reader>(std::move(schema), std::move(fragments));
}
Reference in New Issue View Git Blame Copy Permalink