| /* |
| * Copyright 2019 The Android Open Source Project |
| * |
| * 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. |
| */ |
| |
| package com.android.server.wifi; |
| |
| import android.annotation.NonNull; |
| import android.net.wifi.ScanResult; |
| |
| import com.android.server.wifi.WifiCandidates.Candidate; |
| import com.android.server.wifi.WifiCandidates.ScoredCandidate; |
| |
| import java.util.Collection; |
| |
| /** |
| * A candidate scorer that attempts to match the previous behavior. |
| */ |
| final class CompatibilityScorer implements WifiCandidates.CandidateScorer { |
| |
| /** |
| * This should match WifiNetworkSelector.experimentIdFromIdentifier(getIdentifier()) |
| * when using the default ScoringParams. |
| */ |
| public static final int COMPATIBILITY_SCORER_DEFAULT_EXPID = 42504592; |
| |
| private final ScoringParams mScoringParams; |
| |
| // config_wifi_framework_RSSI_SCORE_OFFSET |
| public static final int RSSI_SCORE_OFFSET = 85; |
| |
| // config_wifi_framework_RSSI_SCORE_SLOPE |
| public static final int RSSI_SCORE_SLOPE_IS_4 = 4; |
| |
| // config_wifi_framework_5GHz_preference_boost_factor |
| public static final int BAND_5GHZ_AWARD_IS_40 = 40; |
| |
| // config_wifiFramework6ghzPreferenceBoostFactor |
| public static final int BAND_6GHZ_AWARD_IS_40 = 40; |
| |
| // config_wifi_framework_SECURITY_AWARD |
| public static final int SECURITY_AWARD_IS_80 = 80; |
| |
| // config_wifi_framework_LAST_SELECTION_AWARD |
| public static final int LAST_SELECTION_AWARD_IS_480 = 480; |
| |
| // config_wifi_framework_current_network_boost |
| public static final int CURRENT_NETWORK_BOOST_IS_16 = 16; |
| |
| // config_wifi_framework_SAME_BSSID_AWARD |
| public static final int SAME_BSSID_AWARD_IS_24 = 24; |
| |
| private static final boolean USE_USER_CONNECT_CHOICE = true; |
| |
| CompatibilityScorer(ScoringParams scoringParams) { |
| mScoringParams = scoringParams; |
| } |
| |
| @Override |
| public String getIdentifier() { |
| return "CompatibilityScorer"; |
| } |
| |
| /** |
| * Calculates an individual candidate's score. |
| */ |
| private ScoredCandidate scoreCandidate(Candidate candidate) { |
| int rssiSaturationThreshold = mScoringParams.getGoodRssi(candidate.getFrequency()); |
| int rssi = Math.min(candidate.getScanRssi(), rssiSaturationThreshold); |
| int score = (rssi + RSSI_SCORE_OFFSET) * RSSI_SCORE_SLOPE_IS_4; |
| |
| if (ScanResult.is6GHz(candidate.getFrequency())) { |
| score += BAND_6GHZ_AWARD_IS_40; |
| } else if (ScanResult.is5GHz(candidate.getFrequency())) { |
| score += BAND_5GHZ_AWARD_IS_40; |
| } |
| score += (int) (candidate.getLastSelectionWeight() * LAST_SELECTION_AWARD_IS_480); |
| |
| if (candidate.isCurrentNetwork()) { |
| // Add both traditional awards, as would be be case with firmware roaming |
| score += CURRENT_NETWORK_BOOST_IS_16 + SAME_BSSID_AWARD_IS_24; |
| } |
| |
| if (!candidate.isOpenNetwork()) { |
| score += SECURITY_AWARD_IS_80; |
| } |
| |
| // To simulate the old strict priority rule, subtract a penalty based on |
| // which nominator added the candidate. |
| score -= 1000 * candidate.getNominatorId(); |
| |
| // The old method breaks ties on the basis of RSSI, which we can |
| // emulate easily since our score does not need to be an integer. |
| double tieBreaker = candidate.getScanRssi() / 1000.0; |
| return new ScoredCandidate(score + tieBreaker, 10, |
| USE_USER_CONNECT_CHOICE, candidate); |
| } |
| |
| @Override |
| public ScoredCandidate scoreCandidates(@NonNull Collection<Candidate> candidates) { |
| ScoredCandidate choice = ScoredCandidate.NONE; |
| for (Candidate candidate : candidates) { |
| ScoredCandidate scoredCandidate = scoreCandidate(candidate); |
| if (scoredCandidate.value > choice.value) { |
| choice = scoredCandidate; |
| } |
| } |
| // Here we just return the highest scored candidate; we could |
| // compute a new score, if desired. |
| return choice; |
| } |
| |
| } |