1
0
Fork 0
arangodb/arangod/Pregel/CommonFormats.h

98 lines
2.8 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2016 ArangoDB GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Simon Grätzer
////////////////////////////////////////////////////////////////////////////////
// NOTE: this files exists primarily to include these algorithm specfic structs
// in the
// cpp files to do template specialization
#ifndef ARANGODB_PREGEL_COMMON_MFORMATS_H
#define ARANGODB_PREGEL_COMMON_MFORMATS_H 1
#include "Pregel/Graph.h"
#include "Pregel/GraphFormat.h"
#include "Pregel/MessageFormat.h"
namespace arangodb {
namespace pregel {
/// A counter for counting unique vertex IDs using a HyperLogLog sketch.
/// @author Aljoscha Krettek, Robert Metzger, Robert Waury
struct HLLCounter {
friend struct HLLCounterFormat;
constexpr static int32_t NUM_BUCKETS = 64;
constexpr static double ALPHA = 0.709;
int32_t getCount();
void addNode(PregelID const& pregelId);
void merge(HLLCounter const& counter);
private:
uint8_t _buckets[NUM_BUCKETS] = {0};
};
/// Effective closeness value
struct ECValue {
HLLCounter counter;
std::vector<int32_t> shortestPaths;
};
struct SCCValue {
std::vector<PregelID> parents;
uint64_t vertexID;
uint64_t color;
};
template <typename T>
struct SenderMessage {
SenderMessage() {}
SenderMessage(PregelID const& pid, T const& val)
: pregelId(pid), value(val) {}
PregelID pregelId;
T value;
};
template <typename T>
struct SenderMessageFormat : public MessageFormat<SenderMessage<T>> {
static_assert(std::is_arithmetic<T>::value, "Message type must be numeric");
SenderMessageFormat() {}
void unwrapValue(VPackSlice s, SenderMessage<T>& senderVal) const override {
VPackArrayIterator array(s);
senderVal.pregelId.shard = (*array).getUInt();
senderVal.pregelId.key = (*(++array)).copyString();
senderVal.value = (*(++array)).getNumber<T>();
}
void addValue(VPackBuilder& arrayBuilder,
SenderMessage<T> const& senderVal) const override {
arrayBuilder.openArray();
arrayBuilder.add(VPackValue(senderVal.pregelId.shard));
arrayBuilder.add(VPackValue(senderVal.pregelId.key));
arrayBuilder.add(VPackValue(senderVal.value));
arrayBuilder.close();
}
};
}
}
#endif