foundationdb/fdbclient/PaxosConfigTransaction.acto...

287 lines
9.3 KiB
C++

/*
* PaxosConfigTransaction.actor.cpp
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "fdbclient/DatabaseContext.h"
#include "fdbclient/PaxosConfigTransaction.h"
#include "flow/actorcompiler.h" // must be last include
class PaxosConfigTransactionImpl {
ConfigTransactionCommitRequest toCommit;
Future<ConfigGeneration> getGenerationFuture;
std::vector<ConfigTransactionInterface> ctis;
int numRetries{ 0 };
bool committed{ false };
Optional<UID> dID;
Database cx;
ACTOR static Future<ConfigGeneration> getGeneration(PaxosConfigTransactionImpl* self) {
state std::vector<Future<ConfigTransactionGetGenerationReply>> getGenerationFutures;
getGenerationFutures.reserve(self->ctis.size());
for (auto const& cti : self->ctis) {
getGenerationFutures.push_back(cti.getGeneration.getReply(ConfigTransactionGetGenerationRequest{}));
}
// FIXME: Must tolerate failures and disagreement
wait(waitForAll(getGenerationFutures));
return getGenerationFutures[0].get().generation;
}
ACTOR static Future<Optional<Value>> get(PaxosConfigTransactionImpl* self, Key key) {
if (!self->getGenerationFuture.isValid()) {
self->getGenerationFuture = getGeneration(self);
}
state ConfigKey configKey = ConfigKey::decodeKey(key);
ConfigGeneration generation = wait(self->getGenerationFuture);
// TODO: Load balance
ConfigTransactionGetReply reply =
wait(self->ctis[0].get.getReply(ConfigTransactionGetRequest{ generation, configKey }));
if (reply.value.present()) {
return reply.value.get().toValue();
} else {
return Optional<Value>{};
}
}
ACTOR static Future<RangeResult> getConfigClasses(PaxosConfigTransactionImpl* self) {
if (!self->getGenerationFuture.isValid()) {
self->getGenerationFuture = getGeneration(self);
}
ConfigGeneration generation = wait(self->getGenerationFuture);
// TODO: Load balance
ConfigTransactionGetConfigClassesReply reply =
wait(self->ctis[0].getClasses.getReply(ConfigTransactionGetConfigClassesRequest{ generation }));
RangeResult result;
result.reserve(result.arena(), reply.configClasses.size());
for (const auto& configClass : reply.configClasses) {
result.push_back_deep(result.arena(), KeyValueRef(configClass, ""_sr));
}
return result;
}
ACTOR static Future<RangeResult> getKnobs(PaxosConfigTransactionImpl* self, Optional<Key> configClass) {
if (!self->getGenerationFuture.isValid()) {
self->getGenerationFuture = getGeneration(self);
}
ConfigGeneration generation = wait(self->getGenerationFuture);
// TODO: Load balance
ConfigTransactionGetKnobsReply reply =
wait(self->ctis[0].getKnobs.getReply(ConfigTransactionGetKnobsRequest{ generation, configClass }));
RangeResult result;
result.reserve(result.arena(), reply.knobNames.size());
for (const auto& knobName : reply.knobNames) {
result.push_back_deep(result.arena(), KeyValueRef(knobName, ""_sr));
}
return result;
}
ACTOR static Future<Void> commit(PaxosConfigTransactionImpl* self) {
if (!self->getGenerationFuture.isValid()) {
self->getGenerationFuture = getGeneration(self);
}
wait(store(self->toCommit.generation, self->getGenerationFuture));
self->toCommit.annotation.timestamp = now();
std::vector<Future<Void>> commitFutures;
commitFutures.reserve(self->ctis.size());
for (const auto& cti : self->ctis) {
commitFutures.push_back(cti.commit.getReply(self->toCommit));
}
// FIXME: Must tolerate failures and disagreement
wait(quorum(commitFutures, commitFutures.size() / 2 + 1));
self->committed = true;
return Void();
}
public:
Future<Version> getReadVersion() {
if (!getGenerationFuture.isValid()) {
getGenerationFuture = getGeneration(this);
}
return map(getGenerationFuture, [](auto const& gen) { return gen.committedVersion; });
}
Optional<Version> getCachedReadVersion() const {
if (getGenerationFuture.isValid() && getGenerationFuture.isReady() && !getGenerationFuture.isError()) {
return getGenerationFuture.get().committedVersion;
} else {
return {};
}
}
Version getCommittedVersion() const { return committed ? getGenerationFuture.get().liveVersion : ::invalidVersion; }
int64_t getApproximateSize() const { return toCommit.expectedSize(); }
void set(KeyRef key, ValueRef value) { toCommit.set(key, value); }
void clear(KeyRef key) { toCommit.clear(key); }
Future<Optional<Value>> get(Key const& key) { return get(this, key); }
Future<RangeResult> getRange(KeyRangeRef keys) {
if (keys == configClassKeys) {
return getConfigClasses(this);
} else if (keys == globalConfigKnobKeys) {
return getKnobs(this, {});
} else if (configKnobKeys.contains(keys) && keys.singleKeyRange()) {
const auto configClass = keys.begin.removePrefix(configKnobKeys.begin);
return getKnobs(this, configClass);
} else {
throw invalid_config_db_range_read();
}
}
Future<Void> onError(Error const& e) {
// TODO: Improve this:
if (e.code() == error_code_transaction_too_old) {
reset();
return delay((1 << numRetries++) * 0.01 * deterministicRandom()->random01());
}
throw e;
}
void debugTransaction(UID dID) { this->dID = dID; }
void reset() {
getGenerationFuture = Future<ConfigGeneration>{};
toCommit = {};
committed = false;
}
void fullReset() {
numRetries = 0;
dID = {};
reset();
}
void checkDeferredError(Error const& deferredError) const {
if (deferredError.code() != invalid_error_code) {
throw deferredError;
}
if (cx.getPtr()) {
cx->checkDeferredError();
}
}
Future<Void> commit() { return commit(this); }
PaxosConfigTransactionImpl(Database const& cx) : cx(cx) {
auto coordinators = cx->getConnectionFile()->getConnectionString().coordinators();
ctis.reserve(coordinators.size());
for (const auto& coordinator : coordinators) {
ctis.emplace_back(coordinator);
}
}
PaxosConfigTransactionImpl(std::vector<ConfigTransactionInterface> const& ctis) : ctis(ctis) {}
};
Future<Version> PaxosConfigTransaction::getReadVersion() {
return impl().getReadVersion();
}
Optional<Version> PaxosConfigTransaction::getCachedReadVersion() const {
return impl().getCachedReadVersion();
}
Future<Optional<Value>> PaxosConfigTransaction::get(Key const& key, Snapshot) {
return impl().get(key);
}
Future<RangeResult> PaxosConfigTransaction::getRange(KeySelector const& begin,
KeySelector const& end,
int limit,
Snapshot snapshot,
Reverse reverse) {
if (reverse) {
throw client_invalid_operation();
}
return impl().getRange(KeyRangeRef(begin.getKey(), end.getKey()));
}
Future<RangeResult> PaxosConfigTransaction::getRange(KeySelector begin,
KeySelector end,
GetRangeLimits limits,
Snapshot snapshot,
Reverse reverse) {
if (reverse) {
throw client_invalid_operation();
}
return impl().getRange(KeyRangeRef(begin.getKey(), end.getKey()));
}
void PaxosConfigTransaction::set(KeyRef const& key, ValueRef const& value) {
return impl().set(key, value);
}
void PaxosConfigTransaction::clear(KeyRef const& key) {
return impl().clear(key);
}
Future<Void> PaxosConfigTransaction::commit() {
return impl().commit();
}
Version PaxosConfigTransaction::getCommittedVersion() const {
return impl().getCommittedVersion();
}
int64_t PaxosConfigTransaction::getApproximateSize() const {
return impl().getApproximateSize();
}
void PaxosConfigTransaction::setOption(FDBTransactionOptions::Option option, Optional<StringRef> value) {
// TODO: Support using this option to determine atomicity
}
Future<Void> PaxosConfigTransaction::onError(Error const& e) {
return impl().onError(e);
}
void PaxosConfigTransaction::cancel() {
// TODO: Implement someday
throw client_invalid_operation();
}
void PaxosConfigTransaction::reset() {
impl().reset();
}
void PaxosConfigTransaction::fullReset() {
impl().fullReset();
}
void PaxosConfigTransaction::debugTransaction(UID dID) {
impl().debugTransaction(dID);
}
void PaxosConfigTransaction::checkDeferredError() const {
impl().checkDeferredError(deferredError);
}
PaxosConfigTransaction::PaxosConfigTransaction(std::vector<ConfigTransactionInterface> const& ctis)
: _impl(std::make_unique<PaxosConfigTransactionImpl>(ctis)) {}
PaxosConfigTransaction::PaxosConfigTransaction() = default;
PaxosConfigTransaction::~PaxosConfigTransaction() = default;
void PaxosConfigTransaction::setDatabase(Database const& cx) {
_impl = std::make_unique<PaxosConfigTransactionImpl>(cx);
}