foundationdb/fdbrpc/ReplicationPolicy.h

283 lines
9.0 KiB
C++

/*
* ReplicationPolicy.h
*
* 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.
*/
#ifndef FLOW_REPLICATION_POLICY_H
#define FLOW_REPLICATION_POLICY_H
#pragma once
#include "flow/flow.h"
#include "fdbrpc/ReplicationTypes.h"
template <class Ar>
void serializeReplicationPolicy(Ar& ar, IRepPolicyRef& policy);
extern void testReplicationPolicy(int nTests);
struct IReplicationPolicy : public ReferenceCounted<IReplicationPolicy> {
IReplicationPolicy() {}
virtual ~IReplicationPolicy() {}
virtual std::string name() const = 0;
virtual std::string info() const = 0;
virtual void addref() { ReferenceCounted<IReplicationPolicy>::addref(); }
virtual void delref() { ReferenceCounted<IReplicationPolicy>::delref(); }
virtual int maxResults() const = 0;
virtual int depth() const = 0;
virtual bool selectReplicas(
LocalitySetRef & fromServers,
std::vector<LocalityEntry> const& alsoServers,
std::vector<LocalityEntry> & results ) = 0;
virtual void traceLocalityRecords(LocalitySetRef const& fromServers);
virtual void traceOneLocalityRecord(Reference<LocalityRecord> record, LocalitySetRef const& fromServers);
virtual bool validate(
std::vector<LocalityEntry> const& solutionSet,
LocalitySetRef const& fromServers ) const = 0;
bool operator == ( const IReplicationPolicy& r ) const { return info() == r.info(); }
bool operator != ( const IReplicationPolicy& r ) const { return info() != r.info(); }
template <class Ar>
void serialize(Ar& ar) {
IRepPolicyRef refThis(this);
serializeReplicationPolicy(ar, refThis);
refThis->delref_no_destroy();
}
// Utility functions
bool selectReplicas(
LocalitySetRef & fromServers,
std::vector<LocalityEntry> & results );
bool validate(
LocalitySetRef const& solutionSet ) const;
bool validateFull(
bool solved,
std::vector<LocalityEntry> const& solutionSet,
std::vector<LocalityEntry> const& alsoServers,
LocalitySetRef const& fromServers );
// Returns a set of the attributes that this policy uses in selection and validation.
std::set<std::string> attributeKeys() const
{ std::set<std::string> keys; this->attributeKeys(&keys); return keys; }
virtual void attributeKeys(std::set<std::string>*) const = 0;
};
template <class Archive>
inline void load( Archive& ar, IRepPolicyRef& value ) {
bool present = (value.getPtr());
ar >> present;
if (present) {
serializeReplicationPolicy(ar, value);
}
else {
value.clear();
}
}
template <class Archive>
inline void save( Archive& ar, const IRepPolicyRef& value ) {
bool present = (value.getPtr());
ar << present;
if (present) {
serializeReplicationPolicy(ar, (IRepPolicyRef&) value);
}
}
struct PolicyOne : IReplicationPolicy, public ReferenceCounted<PolicyOne> {
PolicyOne() {};
virtual ~PolicyOne() {};
virtual std::string name() const { return "One"; }
virtual std::string info() const { return "1"; }
virtual int maxResults() const { return 1; }
virtual int depth() const { return 1; }
virtual bool validate(
std::vector<LocalityEntry> const& solutionSet,
LocalitySetRef const& fromServers ) const;
virtual bool selectReplicas(
LocalitySetRef & fromServers,
std::vector<LocalityEntry> const& alsoServers,
std::vector<LocalityEntry> & results );
template <class Ar>
void serialize(Ar& ar) {
}
virtual void attributeKeys(std::set<std::string>* set) const override { return; }
};
struct PolicyAcross : IReplicationPolicy, public ReferenceCounted<PolicyAcross> {
PolicyAcross(int count, std::string const& attribKey, IRepPolicyRef const policy);
virtual ~PolicyAcross();
virtual std::string name() const { return "Across"; }
virtual std::string info() const
{ return format("%s^%d x ", _attribKey.c_str(), _count) + _policy->info(); }
virtual int maxResults() const { return _count * _policy->maxResults(); }
virtual int depth() const { return 1 + _policy->depth(); }
virtual bool validate(
std::vector<LocalityEntry> const& solutionSet,
LocalitySetRef const& fromServers ) const;
virtual bool selectReplicas(
LocalitySetRef & fromServers,
std::vector<LocalityEntry> const& alsoServers,
std::vector<LocalityEntry> & results );
template <class Ar>
void serialize(Ar& ar) {
serializer(ar, _attribKey, _count);
serializeReplicationPolicy(ar, _policy);
}
static bool compareAddedResults(const std::pair<int, int>& rhs, const std::pair<int, int>& lhs)
{ return (rhs.first < lhs.first) || (!(lhs.first < rhs.first) && (rhs.second < lhs.second)); }
virtual void attributeKeys(std::set<std::string> *set) const override
{ set->insert(_attribKey); _policy->attributeKeys(set); }
protected:
int _count;
std::string _attribKey;
IRepPolicyRef _policy;
// Cache temporary members
std::vector<AttribValue> _usedValues;
std::vector<LocalityEntry> _newResults;
LocalitySetRef _selected;
VectorRef<std::pair<int,int>> _addedResults;
Arena _arena;
};
struct PolicyAnd : IReplicationPolicy, public ReferenceCounted<PolicyAnd> {
PolicyAnd(std::vector<IRepPolicyRef> policies): _policies(policies), _sortedPolicies(policies)
{
// Sort the policy array
std::sort(_sortedPolicies.begin(), _sortedPolicies.end(), PolicyAnd::comparePolicy);
}
virtual ~PolicyAnd() {}
virtual std::string name() const { return "And"; }
virtual std::string info() const {
std::string infoText;
for (auto& policy : _policies) {
infoText += ((infoText.length()) ? " & (" : "(") + policy->info() + ")";
}
if (_policies.size()) infoText = "(" + infoText + ")";
return infoText;
}
virtual int maxResults() const {
int resultsMax = 0;
for (auto& policy : _policies) {
resultsMax += policy->maxResults();
}
return resultsMax;
}
virtual int depth() const {
int policyDepth, depthMax = 0;
for (auto& policy : _policies) {
policyDepth = policy->depth();
if (policyDepth > depthMax) {
depthMax = policyDepth;
}
}
return depthMax;
}
virtual bool validate(
std::vector<LocalityEntry> const& solutionSet,
LocalitySetRef const& fromServers ) const;
virtual bool selectReplicas(
LocalitySetRef & fromServers,
std::vector<LocalityEntry> const& alsoServers,
std::vector<LocalityEntry> & results );
static bool comparePolicy(const IRepPolicyRef& rhs, const IRepPolicyRef& lhs)
{ return (lhs->maxResults() < rhs->maxResults()) || (!(rhs->maxResults() < lhs->maxResults()) && (lhs->depth() < rhs->depth())); }
template <class Ar>
void serialize(Ar& ar) {
int count = _policies.size();
serializer(ar, count);
_policies.resize(count);
for(int i = 0; i < count; i++) {
serializeReplicationPolicy(ar, _policies[i]);
}
if(Ar::isDeserializing) {
_sortedPolicies = _policies;
std::sort(_sortedPolicies.begin(), _sortedPolicies.end(), PolicyAnd::comparePolicy);
}
}
virtual void attributeKeys(std::set<std::string> *set) const override
{ for (const IRepPolicyRef& r : _policies) { r->attributeKeys(set); } }
protected:
std::vector<IRepPolicyRef> _policies;
std::vector<IRepPolicyRef> _sortedPolicies;
};
extern int testReplication();
template <class Ar>
void serializeReplicationPolicy(Ar& ar, IRepPolicyRef& policy) {
if(Ar::isDeserializing) {
StringRef name;
serializer(ar, name);
if(name == LiteralStringRef("One")) {
PolicyOne* pointer = new PolicyOne();
pointer->serialize(ar);
policy = IRepPolicyRef(pointer);
}
else if(name == LiteralStringRef("Across")) {
PolicyAcross* pointer = new PolicyAcross(0, "", IRepPolicyRef());
pointer->serialize(ar);
policy = IRepPolicyRef(pointer);
}
else if(name == LiteralStringRef("And")) {
PolicyAnd* pointer = new PolicyAnd({});
pointer->serialize(ar);
policy = IRepPolicyRef(pointer);
}
else if(name == LiteralStringRef("None")) {
policy = IRepPolicyRef();
}
else {
TraceEvent(SevError, "SerializingInvalidPolicyType")
.detailext("PolicyName", name);
}
}
else {
std::string name = policy ? policy->name() : "None";
Standalone<StringRef> nameRef = StringRef(name);
serializer(ar, nameRef);
if(name == "One") {
((PolicyOne*)policy.getPtr())->serialize(ar);
}
else if(name == "Across") {
((PolicyAcross*)policy.getPtr())->serialize(ar);
}
else if(name == "And") {
((PolicyAnd*)policy.getPtr())->serialize(ar);
}
else if(name == "None") {}
else {
TraceEvent(SevError, "SerializingInvalidPolicyType")
.detail("PolicyName", name);
}
}
}
#endif