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// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#pragma once
#include "nativerankfeature.h"
#include "queryterm.h"
#include <vespa/fastos/dynamiclibrary.h>
namespace search::features {
/**
* This struct contains parameters used by the executor.
**/
struct NativeFieldMatchParam : public NativeParamBase
{
static const uint32_t NOT_DEF_FIELD_LENGTH;
NativeFieldMatchParam() : NativeParamBase(), firstOccTable(NULL), numOccTable(NULL), averageFieldLength(NOT_DEF_FIELD_LENGTH), firstOccImportance(0.5) { }
const fef::Table * firstOccTable;
const fef::Table * numOccTable;
uint32_t averageFieldLength;
feature_t firstOccImportance;
};
class NativeFieldMatchParams : public NativeRankParamsBase<NativeFieldMatchParam>
{
public:
uint32_t minFieldLength;
NativeFieldMatchParams() : minFieldLength(6) { }
};
/**
* Implements the executor for calculating the native field match score.
**/
class NativeFieldMatchExecutor : public fef::FeatureExecutor
{
private:
typedef std::vector<fef::TermFieldHandle> HandleVector;
class MyQueryTerm : public QueryTerm
{
private:
HandleVector _handles; // field match handles
public:
MyQueryTerm(const QueryTerm & qt) : QueryTerm(qt), _handles() {}
HandleVector &handles() { return _handles; }
const HandleVector &handles() const { return _handles; }
};
const NativeFieldMatchParams & _params;
std::vector<MyQueryTerm> _queryTerms;
uint32_t _totalTermWeight;
feature_t _divisor;
const fef::MatchData *_md;
VESPA_DLL_LOCAL feature_t calculateScore(const MyQueryTerm &qt, uint32_t docId);
uint32_t getFieldLength(const NativeFieldMatchParam & param, uint32_t fieldLength) const {
if (param.averageFieldLength != NativeFieldMatchParam::NOT_DEF_FIELD_LENGTH) {
return param.averageFieldLength;
}
return fieldLength;
}
feature_t getFirstOccBoost(const NativeFieldMatchParam & param, uint32_t position, uint32_t fieldLength) const {
const fef::Table * table = param.firstOccTable;
size_t index = (position * (table->size() - 1)) / (std::max(_params.minFieldLength, fieldLength) - 1);
return table->get(index);
}
feature_t getNumOccBoost(const NativeFieldMatchParam & param, uint32_t occs, uint32_t fieldLength) const {
const fef::Table * table = param.numOccTable;
size_t index = (occs * (table->size() - 1)) / (std::max(_params.minFieldLength, fieldLength));
return table->get(index);
}
virtual void handle_bind_match_data(const fef::MatchData &md) override;
public:
NativeFieldMatchExecutor(const fef::IQueryEnvironment & env,
const NativeFieldMatchParams & params);
void execute(uint32_t docId) override;
feature_t getFirstOccBoost(uint32_t field, uint32_t position, uint32_t fieldLength) const {
return getFirstOccBoost(_params.vector[field], position, fieldLength);
}
feature_t getNumOccBoost(uint32_t field, uint32_t occs, uint32_t fieldLength) const {
return getNumOccBoost(_params.vector[field], occs, fieldLength);
}
bool empty() const { return _queryTerms.empty(); }
};
/**
* Implements the blueprint for the native field match executor.
**/
class NativeFieldMatchBlueprint : public fef::Blueprint {
private:
NativeFieldMatchParams _params;
vespalib::string _defaultFirstOcc;
vespalib::string _defaultNumOcc;
public:
NativeFieldMatchBlueprint();
~NativeFieldMatchBlueprint();
void visitDumpFeatures(const fef::IIndexEnvironment & env, fef::IDumpFeatureVisitor & visitor) const override;
fef::Blueprint::UP createInstance() const override;
fef::ParameterDescriptions getDescriptions() const override {
return fef::ParameterDescriptions().desc().field().repeat();
}
bool setup(const fef::IIndexEnvironment & env, const fef::ParameterList & params) override;
fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment & env, vespalib::Stash &stash) const override;
const NativeFieldMatchParams & getParams() const { return _params; }
};
}
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