113 lines
4.1 KiB
C
113 lines
4.1 KiB
C
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/*
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* Copyright (C) 2013, The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef LATINIME_FORGETTING_CURVE_UTILS_H
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#define LATINIME_FORGETTING_CURVE_UTILS_H
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#include <vector>
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#include "defines.h"
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#include "dictionary/property/historical_info.h"
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#include "dictionary/utils/entry_counters.h"
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namespace latinime {
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class HeaderPolicy;
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class ForgettingCurveUtils {
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public:
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static const HistoricalInfo createUpdatedHistoricalInfo(
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const HistoricalInfo *const originalHistoricalInfo, const int newProbability,
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const HistoricalInfo *const newHistoricalInfo, const HeaderPolicy *const headerPolicy);
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static const HistoricalInfo createHistoricalInfoToSave(
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const HistoricalInfo *const originalHistoricalInfo,
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const HeaderPolicy *const headerPolicy);
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static int decodeProbability(const HistoricalInfo *const historicalInfo,
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const HeaderPolicy *const headerPolicy);
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static bool needsToKeep(const HistoricalInfo *const historicalInfo,
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const HeaderPolicy *const headerPolicy);
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static bool needsToDecay(const bool mindsBlockByDecay, const EntryCounts &entryCounters,
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const HeaderPolicy *const headerPolicy);
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// TODO: Improve probability computation method and remove this.
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static int getProbabilityBiasForNgram(const int n) {
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return (n - 1) * MULTIPLIER_TWO_IN_PROBABILITY_SCALE;
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}
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AK_FORCE_INLINE static int getEntryCountHardLimit(const int maxEntryCount) {
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return static_cast<int>(static_cast<float>(maxEntryCount)
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* ENTRY_COUNT_HARD_LIMIT_WEIGHT);
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}
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private:
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DISALLOW_IMPLICIT_CONSTRUCTORS(ForgettingCurveUtils);
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class ProbabilityTable {
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public:
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ProbabilityTable();
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int getProbability(const int tableId, const int level,
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const int elapsedTimeStepCount) const {
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return mTables[tableId][level][elapsedTimeStepCount];
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}
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private:
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DISALLOW_COPY_AND_ASSIGN(ProbabilityTable);
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static const int PROBABILITY_TABLE_COUNT;
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static const int WEAK_PROBABILITY_TABLE_ID;
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static const int MODEST_PROBABILITY_TABLE_ID;
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static const int STRONG_PROBABILITY_TABLE_ID;
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static const int AGGRESSIVE_PROBABILITY_TABLE_ID;
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static const int WEAK_MAX_PROBABILITY;
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static const int MODEST_BASE_PROBABILITY;
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static const int STRONG_BASE_PROBABILITY;
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static const int AGGRESSIVE_BASE_PROBABILITY;
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std::vector<std::vector<std::vector<int>>> mTables;
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static int getBaseProbabilityForLevel(const int tableId, const int level);
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};
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static const int MULTIPLIER_TWO_IN_PROBABILITY_SCALE;
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static const int DECAY_INTERVAL_SECONDS;
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static const int MAX_LEVEL;
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static const int MIN_VISIBLE_LEVEL;
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static const int MAX_ELAPSED_TIME_STEP_COUNT;
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static const int DISCARD_LEVEL_ZERO_ENTRY_TIME_STEP_COUNT_THRESHOLD;
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static const int OCCURRENCES_TO_RAISE_THE_LEVEL;
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static const int DURATION_TO_LOWER_THE_LEVEL_IN_SECONDS;
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static const float ENTRY_COUNT_HARD_LIMIT_WEIGHT;
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static const ProbabilityTable sProbabilityTable;
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static int backoff(const int unigramProbability);
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static int getElapsedTimeStepCount(const int timestamp, const int durationToLevelDown);
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static int clampToVisibleEntryLevelRange(const int level);
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static int clampToValidLevelRange(const int level);
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static int clampToValidCountRange(const int count, const HeaderPolicy *const headerPolicy);
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static int clampToValidTimeStepCountRange(const int timeStepCount);
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};
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} // namespace latinime
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#endif /* LATINIME_FORGETTING_CURVE_UTILS_H */
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