/*
 * StorageServerInterface.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 FDBCLIENT_STORAGESERVERINTERFACE_H
#define FDBCLIENT_STORAGESERVERINTERFACE_H
#pragma once

#include "fdbclient/FDBTypes.h"
#include "fdbrpc/Locality.h"
#include "fdbrpc/QueueModel.h"
#include "fdbrpc/fdbrpc.h"
#include "fdbrpc/LoadBalance.actor.h"
#include "fdbrpc/Stats.h"
#include "fdbrpc/TimedRequest.h"
#include "fdbclient/TagThrottle.h"

// Dead code, removed in the next protocol version
struct VersionReply {
	constexpr static FileIdentifier file_identifier = 3;

	Version version;
	VersionReply() = default;
	explicit VersionReply(Version version) : version(version) {}

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, version);
	}
};

struct StorageServerInterface {
	constexpr static FileIdentifier file_identifier = 15302073;
	enum { BUSY_ALLOWED = 0, BUSY_FORCE = 1, BUSY_LOCAL = 2 };

	enum { LocationAwareLoadBalance = 1 };
	enum { AlwaysFresh = 0 };

	LocalityData locality;
	UID uniqueID;

	RequestStream<struct GetValueRequest> getValue;
	RequestStream<struct GetKeyRequest> getKey;

	// Throws a wrong_shard_server if the keys in the request or result depend on data outside this server OR if a large selector offset prevents
	// all data from being read in one range read
	RequestStream<struct GetKeyValuesRequest> getKeyValues;

	RequestStream<struct GetShardStateRequest> getShardState;
	RequestStream<struct WaitMetricsRequest> waitMetrics;
	RequestStream<struct SplitMetricsRequest> splitMetrics;
	RequestStream<struct GetStorageMetricsRequest> getStorageMetrics;
	RequestStream<ReplyPromise<Void>> waitFailure;
	RequestStream<struct StorageQueuingMetricsRequest> getQueuingMetrics;

	RequestStream<ReplyPromise<KeyValueStoreType>> getKeyValueStoreType;
	RequestStream<struct WatchValueRequest> watchValue;
	RequestStream<struct ReadHotSubRangeRequest> getReadHotRanges;
	RequestStream<struct SplitRangeRequest> getRangeSplitPoints;

	explicit StorageServerInterface(UID uid) : uniqueID( uid ) {}
	StorageServerInterface() : uniqueID( deterministicRandom()->randomUniqueID() ) {}
	NetworkAddress address() const { return getValue.getEndpoint().getPrimaryAddress(); }
	NetworkAddress stableAddress() const { return getValue.getEndpoint().getStableAddress(); }
	Optional<NetworkAddress> secondaryAddress() const { return getValue.getEndpoint().addresses.secondaryAddress; }
	UID id() const { return uniqueID; }
	std::string toString() const { return id().shortString(); }
	template <class Ar>
	void serialize(Ar& ar) {
		// StorageServerInterface is persisted in the database, so changes here have to be versioned carefully!
		//To change this serialization, ProtocolVersion::ServerListValue must be updated, and downgrades need to be considered

		if (ar.protocolVersion().hasSmallEndpoints()) {
			serializer(ar, uniqueID, locality, getValue);
			if( Ar::isDeserializing ) {
				getKey = RequestStream<struct GetKeyRequest>( getValue.getEndpoint().getAdjustedEndpoint(1) );
				getKeyValues = RequestStream<struct GetKeyValuesRequest>( getValue.getEndpoint().getAdjustedEndpoint(2) );
				getShardState = RequestStream<struct GetShardStateRequest>( getValue.getEndpoint().getAdjustedEndpoint(3) );
				waitMetrics = RequestStream<struct WaitMetricsRequest>( getValue.getEndpoint().getAdjustedEndpoint(4) );
				splitMetrics = RequestStream<struct SplitMetricsRequest>( getValue.getEndpoint().getAdjustedEndpoint(5) );
				getStorageMetrics = RequestStream<struct GetStorageMetricsRequest>( getValue.getEndpoint().getAdjustedEndpoint(6) );
				waitFailure = RequestStream<ReplyPromise<Void>>( getValue.getEndpoint().getAdjustedEndpoint(7) );
				getQueuingMetrics = RequestStream<struct StorageQueuingMetricsRequest>( getValue.getEndpoint().getAdjustedEndpoint(8) );
				getKeyValueStoreType = RequestStream<ReplyPromise<KeyValueStoreType>>( getValue.getEndpoint().getAdjustedEndpoint(9) );
				watchValue = RequestStream<struct WatchValueRequest>( getValue.getEndpoint().getAdjustedEndpoint(10) );
				getReadHotRanges = RequestStream<struct ReadHotSubRangeRequest>( getValue.getEndpoint().getAdjustedEndpoint(11) );
				getRangeSplitPoints = RequestStream<struct SplitRangeRequest>(getValue.getEndpoint().getAdjustedEndpoint(12));
			}
		} else {
			ASSERT(Ar::isDeserializing);
			if constexpr (is_fb_function<Ar>) {
				ASSERT(false);
			}
			serializer(ar, uniqueID, locality, getValue, getKey, getKeyValues, getShardState, waitMetrics,
					splitMetrics, getStorageMetrics, waitFailure, getQueuingMetrics, getKeyValueStoreType);
			if (ar.protocolVersion().hasWatches()) serializer(ar, watchValue);
		}
	}
	bool operator == (StorageServerInterface const& s) const { return uniqueID == s.uniqueID; }
	bool operator < (StorageServerInterface const& s) const { return uniqueID < s.uniqueID; }
	void initEndpoints() {
		std::vector<std::pair<FlowReceiver*, TaskPriority>> streams;
		streams.push_back(getValue.getReceiver(TaskPriority::LoadBalancedEndpoint));
		streams.push_back(getKey.getReceiver(TaskPriority::LoadBalancedEndpoint));
		streams.push_back(getKeyValues.getReceiver(TaskPriority::LoadBalancedEndpoint));
		streams.push_back(getShardState.getReceiver());
		streams.push_back(waitMetrics.getReceiver());
		streams.push_back(splitMetrics.getReceiver());
		streams.push_back(getStorageMetrics.getReceiver());
		streams.push_back(waitFailure.getReceiver());
		streams.push_back(getQueuingMetrics.getReceiver());
		streams.push_back(getKeyValueStoreType.getReceiver());
		streams.push_back(watchValue.getReceiver());
		streams.push_back(getReadHotRanges.getReceiver());
		streams.push_back(getRangeSplitPoints.getReceiver());
		FlowTransport::transport().addEndpoints(streams);
	}
};

struct StorageInfo : NonCopyable, public ReferenceCounted<StorageInfo> {
	Tag tag;
	StorageServerInterface interf;
	StorageInfo() : tag(invalidTag) {}
};

struct ServerCacheInfo {
	std::vector<Tag> tags;
	std::vector<Reference<StorageInfo>> src_info;
	std::vector<Reference<StorageInfo>> dest_info;

	void populateTags() {
		if (tags.size()) return;

		for (const auto& info : src_info) {
			tags.push_back(info->tag);
		}
		for (const auto& info : dest_info) {
			tags.push_back(info->tag);
		}
		uniquify(tags);
	}
};

struct GetValueReply : public LoadBalancedReply {
	constexpr static FileIdentifier file_identifier = 1378929;
	Optional<Value> value;
	bool cached;

	GetValueReply() : cached(false) {}
	GetValueReply(Optional<Value> value, bool cached) : value(value), cached(cached) {}

	template <class Ar>
	void serialize( Ar& ar ) {
		serializer(ar, LoadBalancedReply::penalty, LoadBalancedReply::error, value, cached);
	}
};

struct GetValueRequest : TimedRequest {
	constexpr static FileIdentifier file_identifier = 8454530;
	SpanID spanContext;
	Key key;
	Version version;
	Optional<TagSet> tags;
	Optional<UID> debugID;
	ReplyPromise<GetValueReply> reply;

	GetValueRequest(){}
	GetValueRequest(SpanID spanContext, const Key& key, Version ver, Optional<TagSet> tags, Optional<UID> debugID)
	  : spanContext(spanContext), key(key), version(ver), tags(tags), debugID(debugID) {}

	template <class Ar>
	void serialize( Ar& ar ) {
		serializer(ar, key, version, tags, debugID, reply, spanContext);
	}
};

struct WatchValueReply {
	constexpr static FileIdentifier file_identifier = 3;

	Version version;
	bool cached = false;
	WatchValueReply() = default;
	explicit WatchValueReply(Version version) : version(version) {}

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, version, cached);
	}
};

struct WatchValueRequest {
	constexpr static FileIdentifier file_identifier = 14747733;
	SpanID spanContext;
	Key key;
	Optional<Value> value;
	Version version;
	Optional<TagSet> tags;
	Optional<UID> debugID;
	ReplyPromise<WatchValueReply> reply;

	WatchValueRequest(){}
	WatchValueRequest(SpanID spanContext, const Key& key, Optional<Value> value, Version ver, Optional<TagSet> tags,
	                  Optional<UID> debugID)
	  : spanContext(spanContext), key(key), value(value), version(ver), tags(tags), debugID(debugID) {}

	template <class Ar>
	void serialize( Ar& ar ) {
		serializer(ar, key, value, version, tags, debugID, reply, spanContext);
	}
};

struct GetKeyValuesReply : public LoadBalancedReply {
	constexpr static FileIdentifier file_identifier = 1783066;
	Arena arena;
	VectorRef<KeyValueRef, VecSerStrategy::String> data;
	Version version; // useful when latestVersion was requested
	bool more;
	bool cached = false;

	GetKeyValuesReply() : version(invalidVersion), more(false), cached(false) {}

	template <class Ar>
	void serialize( Ar& ar ) {
		serializer(ar, LoadBalancedReply::penalty, LoadBalancedReply::error, data, version, more, cached, arena);
	}
};

struct GetKeyValuesRequest : TimedRequest {
	constexpr static FileIdentifier file_identifier = 6795746;
	SpanID spanContext;
	Arena arena;
	KeySelectorRef begin, end;
	Version version;		// or latestVersion
	int limit, limitBytes;
	bool isFetchKeys;
	Optional<TagSet> tags;
	Optional<UID> debugID;
	ReplyPromise<GetKeyValuesReply> reply;

	GetKeyValuesRequest() : isFetchKeys(false) {}
	template <class Ar>
	void serialize( Ar& ar ) {
		serializer(ar, begin, end, version, limit, limitBytes, isFetchKeys, tags, debugID, reply, spanContext, arena);
	}
};

struct GetKeyReply : public LoadBalancedReply {
	constexpr static FileIdentifier file_identifier = 11226513;
	KeySelector sel;
	bool cached;

	GetKeyReply() : cached(false) {}
	GetKeyReply(KeySelector sel, bool cached) : sel(sel), cached(cached) {}

	template <class Ar>
	void serialize( Ar& ar ) {
		serializer(ar, LoadBalancedReply::penalty, LoadBalancedReply::error, sel, cached);
	}
};

struct GetKeyRequest : TimedRequest {
	constexpr static FileIdentifier file_identifier = 10457870;
	SpanID spanContext;
	Arena arena;
	KeySelectorRef sel;
	Version version;		// or latestVersion
	Optional<TagSet> tags;
	Optional<UID> debugID;
	ReplyPromise<GetKeyReply> reply;

	GetKeyRequest() {}
	GetKeyRequest(SpanID spanContext, KeySelectorRef const& sel, Version version, Optional<TagSet> tags,
	              Optional<UID> debugID)
	  : spanContext(spanContext), sel(sel), version(version), debugID(debugID) {}

	template <class Ar>
	void serialize( Ar& ar ) {
		serializer(ar, sel, version, tags, debugID, reply, spanContext, arena);
	}
};

struct GetShardStateReply {
	constexpr static FileIdentifier file_identifier = 0;

	Version first;
	Version second;
	GetShardStateReply() = default;
	GetShardStateReply(Version first, Version second) : first(first), second(second) {}

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, first, second);
	}
};

struct GetShardStateRequest {
	constexpr static FileIdentifier file_identifier = 15860168;
	enum waitMode {
		NO_WAIT = 0,
		FETCHING = 1,
		READABLE = 2
	};

	KeyRange keys;
	int32_t mode;
	ReplyPromise<GetShardStateReply> reply;
	GetShardStateRequest() {}
	GetShardStateRequest( KeyRange const& keys, waitMode mode ) : keys(keys), mode(mode) {}

	template <class Ar>
	void serialize( Ar& ar ) {
		serializer(ar, keys, mode, reply);
	}
};

struct StorageMetrics {
	constexpr static FileIdentifier file_identifier = 13622226;
	int64_t bytes = 0;				// total storage
	// FIXME: currently, neither of bytesPerKSecond or iosPerKSecond are actually used in DataDistribution calculations.
	// This may change in the future, but this comment is left here to avoid any confusion for the time being.
	int64_t bytesPerKSecond = 0;	// network bandwidth (average over 10s)
	int64_t iosPerKSecond = 0;
	int64_t bytesReadPerKSecond = 0;

	static const int64_t infinity = 1LL<<60;

	bool allLessOrEqual( const StorageMetrics& rhs ) const {
		return bytes <= rhs.bytes && bytesPerKSecond <= rhs.bytesPerKSecond && iosPerKSecond <= rhs.iosPerKSecond &&
		       bytesReadPerKSecond <= rhs.bytesReadPerKSecond;
	}
	void operator += ( const StorageMetrics& rhs ) {
		bytes += rhs.bytes;
		bytesPerKSecond += rhs.bytesPerKSecond;
		iosPerKSecond += rhs.iosPerKSecond;
		bytesReadPerKSecond += rhs.bytesReadPerKSecond;
	}
	void operator -= ( const StorageMetrics& rhs ) {
		bytes -= rhs.bytes;
		bytesPerKSecond -= rhs.bytesPerKSecond;
		iosPerKSecond -= rhs.iosPerKSecond;
		bytesReadPerKSecond -= rhs.bytesReadPerKSecond;
	}
	template <class F>
	void operator *= ( F f ) {
		bytes *= f;
		bytesPerKSecond *= f;
		iosPerKSecond *= f;
		bytesReadPerKSecond *= f;
	}
	bool allZero() const { return !bytes && !bytesPerKSecond && !iosPerKSecond && !bytesReadPerKSecond; }

	template <class Ar>
	void serialize( Ar& ar ) {
		serializer(ar, bytes, bytesPerKSecond, iosPerKSecond, bytesReadPerKSecond);
	}

	void negate() { operator*=(-1.0); }
	StorageMetrics operator - () const { StorageMetrics x(*this); x.negate(); return x; }
	StorageMetrics operator + ( const StorageMetrics& r ) const { StorageMetrics x(*this); x+=r; return x; }
	StorageMetrics operator - ( const StorageMetrics& r ) const { StorageMetrics x(r); x.negate(); x+=*this; return x; }
	template <class F> StorageMetrics operator * ( F f ) const { StorageMetrics x(*this); x*=f; return x; }

	bool operator == ( StorageMetrics const& rhs ) const {
		return bytes == rhs.bytes && bytesPerKSecond == rhs.bytesPerKSecond && iosPerKSecond == rhs.iosPerKSecond &&
		       bytesReadPerKSecond == rhs.bytesReadPerKSecond;
	}

	std::string toString() const {
		return format("Bytes: %lld, BPerKSec: %lld, iosPerKSec: %lld, BReadPerKSec: %lld", bytes, bytesPerKSecond,
		              iosPerKSecond, bytesReadPerKSecond);
	}
};

struct WaitMetricsRequest {
	// Waits for any of the given minimum or maximum metrics to be exceeded, and then returns the current values
	// Send a reversed range for min, max to receive an immediate report
	constexpr static FileIdentifier file_identifier = 1795961;
	Arena arena;
	KeyRangeRef keys;
	StorageMetrics min, max;
	ReplyPromise<StorageMetrics> reply;

	WaitMetricsRequest() {}
	WaitMetricsRequest( KeyRangeRef const& keys, StorageMetrics const& min, StorageMetrics const& max )
		: keys( arena, keys ), min( min ), max( max )
	{
	}

	template <class Ar>
	void serialize( Ar& ar ) {
		serializer(ar, keys, min, max, reply, arena);
	}
};

struct SplitMetricsReply {
	constexpr static FileIdentifier file_identifier = 11530792;
	Standalone<VectorRef<KeyRef>> splits;
	StorageMetrics used;

	template <class Ar>
	void serialize( Ar& ar ) {
		serializer(ar, splits, used);
	}
};

struct SplitMetricsRequest {
	constexpr static FileIdentifier file_identifier = 10463876;
	Arena arena;
	KeyRangeRef keys;
	StorageMetrics limits;
	StorageMetrics used;
	StorageMetrics estimated;
	bool isLastShard;
	ReplyPromise<SplitMetricsReply> reply;

	SplitMetricsRequest() {}
	SplitMetricsRequest( KeyRangeRef const& keys, StorageMetrics const& limits, StorageMetrics const& used, StorageMetrics const& estimated, bool isLastShard ) : keys( arena, keys ), limits( limits ), used( used ), estimated( estimated ), isLastShard( isLastShard ) {}

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, keys, limits, used, estimated, isLastShard, reply, arena);
	}
};

// Should always be used inside a `Standalone`.
struct ReadHotRangeWithMetrics {
	KeyRangeRef keys;
	double density;
	double readBandwidth;

	ReadHotRangeWithMetrics() = default;
	ReadHotRangeWithMetrics(KeyRangeRef const& keys, double density, double readBandwidth)
	  : keys(keys), density(density), readBandwidth(readBandwidth) {}

	ReadHotRangeWithMetrics(Arena& arena, const ReadHotRangeWithMetrics& rhs)
	  : keys(arena, rhs.keys), density(rhs.density), readBandwidth(rhs.readBandwidth) {}

	int expectedSize() { return keys.expectedSize() + sizeof(density) + sizeof(readBandwidth); }

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, keys, density, readBandwidth);
	}
};

struct ReadHotSubRangeReply {
	constexpr static FileIdentifier file_identifier = 10424537;
	Standalone<VectorRef<ReadHotRangeWithMetrics>> readHotRanges;

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, readHotRanges);
	}
};
struct ReadHotSubRangeRequest {
	constexpr static FileIdentifier file_identifier = 10259266;
	Arena arena;
	KeyRangeRef keys;
	ReplyPromise<ReadHotSubRangeReply> reply;

	ReadHotSubRangeRequest() {}
	ReadHotSubRangeRequest(KeyRangeRef const& keys) : keys(arena, keys) {}

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, keys, reply, arena);
	}
};

struct SplitRangeReply {
	constexpr static FileIdentifier file_identifier = 11813134;
	// If the given range can be divided, contains the split points.
	// If the given range cannot be divided(for exmaple its total size is smaller than the chunk size), this would be
	// empty
	Standalone<VectorRef<KeyRef>> splitPoints;

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, splitPoints);
	}
};
struct SplitRangeRequest {
	constexpr static FileIdentifier file_identifier = 10725174;
	Arena arena;
	KeyRangeRef keys;
	int64_t chunkSize;
	ReplyPromise<SplitRangeReply> reply;

	SplitRangeRequest() {}
	SplitRangeRequest(KeyRangeRef const& keys, int64_t chunkSize) : keys(arena, keys), chunkSize(chunkSize) {}

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, keys, chunkSize, reply, arena);
	}
};

struct GetStorageMetricsReply {
	constexpr static FileIdentifier file_identifier = 15491478;
	StorageMetrics load;
	StorageMetrics available;
	StorageMetrics capacity;
	double bytesInputRate;
	int64_t versionLag;
	double lastUpdate;

	GetStorageMetricsReply() : bytesInputRate(0) {}

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, load, available, capacity, bytesInputRate, versionLag, lastUpdate);
	}
};

struct GetStorageMetricsRequest {
	constexpr static FileIdentifier file_identifier = 13290999;
	ReplyPromise<GetStorageMetricsReply> reply;

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, reply);
	}
};

struct StorageQueuingMetricsReply {
	constexpr static FileIdentifier file_identifier = 7633366;
	double localTime;
	int64_t instanceID;  // changes if bytesDurable and bytesInput reset
	int64_t bytesDurable, bytesInput;
	StorageBytes storageBytes;
	Version version; // current storage server version
	Version durableVersion; // latest version durable on storage server
	double cpuUsage;
	double diskUsage;
	double localRateLimit;
	Optional<TransactionTag> busiestTag;
	double busiestTagFractionalBusyness;
	double busiestTagRate;

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, localTime, instanceID, bytesDurable, bytesInput, version, storageBytes, durableVersion, cpuUsage, diskUsage, localRateLimit, busiestTag, busiestTagFractionalBusyness, busiestTagRate);
	}
};

struct StorageQueuingMetricsRequest {
	// SOMEDAY: Send threshold value to avoid polling faster than the information changes?
	constexpr static FileIdentifier file_identifier = 3978640;
	ReplyPromise<struct StorageQueuingMetricsReply> reply;

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, reply);
	}
};

#endif