/* * Copyright (C) 2012 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 android.bordeaux.services; import android.bordeaux.services.ILearning_StochasticLinearRanker; import android.bordeaux.services.StringFloat; import android.content.Context; import android.os.RemoteException; import android.util.Log; import java.util.ArrayList; import java.util.List; import java.util.HashMap; import java.util.Map; /** Ranker for the Learning framework. * For training: call updateClassifier with a pair of samples. * For ranking: call scoreSample to the score of the rank * Data is represented as sparse key, value pair. And key is a String, value * is a float. * Note: since the actual ranker is running in a remote the service. * Sometimes the connection may be lost or not established. * */ public class BordeauxRanker { static final String TAG = "BordeauxRanker"; static final String RANKER_NOTAVAILABLE = "Ranker not Available"; private Context mContext; private String mName; private ILearning_StochasticLinearRanker mRanker; private ArrayList<StringFloat> getArrayList(final HashMap<String, Float> sample) { ArrayList<StringFloat> stringfloat_sample = new ArrayList<StringFloat>(); for (Map.Entry<String, Float> x : sample.entrySet()) { StringFloat v = new StringFloat(); v.key = x.getKey(); v.value = x.getValue(); stringfloat_sample.add(v); } return stringfloat_sample; } public boolean retrieveRanker() { if (mRanker == null) mRanker = BordeauxManagerService.getRanker(mContext, mName); // if classifier is not available, return false if (mRanker == null) { Log.e(TAG,"Ranker not available."); return false; } return true; } public BordeauxRanker(Context context) { mContext = context; mName = "defaultRanker"; mRanker = BordeauxManagerService.getRanker(context, mName); } public BordeauxRanker(Context context, String name) { mContext = context; mName = name; mRanker = BordeauxManagerService.getRanker(context, mName); } // Update the ranker with two samples, sample1 has higher rank than // sample2. public boolean update(final HashMap<String, Float> sample1, final HashMap<String, Float> sample2) { if (!retrieveRanker()) return false; try { mRanker.UpdateClassifier(getArrayList(sample1), getArrayList(sample2)); } catch (RemoteException e) { Log.e(TAG,"Exception: updateClassifier."); return false; } return true; } public boolean reset() { if (!retrieveRanker()){ Log.e(TAG,"Exception: Ranker is not availible"); return false; } try { mRanker.ResetRanker(); return true; } catch (RemoteException e) { } return false; } public float scoreSample(final HashMap<String, Float> sample) { if (!retrieveRanker()) throw new RuntimeException(RANKER_NOTAVAILABLE); try { return mRanker.ScoreSample(getArrayList(sample)); } catch (RemoteException e) { Log.e(TAG,"Exception: scoring the sample."); throw new RuntimeException(RANKER_NOTAVAILABLE); } } public boolean setPriorWeight(final HashMap<String, Float> sample) { if (!retrieveRanker()) throw new RuntimeException(RANKER_NOTAVAILABLE); try { return mRanker.SetModelPriorWeight(getArrayList(sample)); } catch (RemoteException e) { Log.e(TAG,"Exception: set prior Weights"); throw new RuntimeException(RANKER_NOTAVAILABLE); } } public boolean setParameter(String key, String value) { if (!retrieveRanker()) throw new RuntimeException(RANKER_NOTAVAILABLE); try { return mRanker.SetModelParameter(key, value); } catch (RemoteException e) { Log.e(TAG,"Exception: Setting Parameter"); throw new RuntimeException(RANKER_NOTAVAILABLE); } } }