android/quicksearchbox/Config.java

/*
 * Copyright (C) 2009 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.quicksearchbox;

import android.content.Context;
import android.content.res.Resources;
import android.os.Process;
import android.util.Log;

import java.util.HashSet;

/**
 * Provides values for configurable parameters in all of QSB.
 *
 * All the methods in this class return fixed default values. Subclasses may
 * make these values server-side settable.
 *
 */
public class Config {

    private static final String TAG = "QSB.Config";

    private static final long DAY_MILLIS = 86400000L;

    private static final int MAX_PROMOTED_SUGGESTIONS = 8;
    private static final int MAX_RESULTS_PER_SOURCE = 50;
    private static final long SOURCE_TIMEOUT_MILLIS = 10000;

    private static final int QUERY_THREAD_MAX_POOL_SIZE = 4;
    private static final long QUERY_THREAD_KEEPALIVE_MILLIS = 30000;
    private static final int QUERY_THREAD_PRIORITY =
            Process.THREAD_PRIORITY_BACKGROUND + Process.THREAD_PRIORITY_MORE_FAVORABLE;

    private static final long SOURCE_RESULT_PUBLISH_DELAY_MILLIS = 200;

    private static final long MAX_STAT_AGE_MILLIS = 7 * DAY_MILLIS;
    private static final long MAX_SOURCE_EVENT_AGE_MILLIS = 30 * DAY_MILLIS;
    private static final int MIN_IMPRESSIONS_FOR_SOURCE_RANKING = 5;
    private static final int MIN_CLICKS_FOR_SOURCE_RANKING = 3;
    private static final int MAX_SHORTCUTS_RETURNED = 12;

    private static final long THREAD_START_DELAY_MILLIS = 100;

    private Context mContext;
    private HashSet<String> mTrustedPackages;

    /**
     * Creates a new config that uses hard-coded default values.
     */
    public Config(Context context) {
        mContext = context;
    }

    private HashSet<String> loadTrustedPackages() {
        HashSet<String> trusted = new HashSet<String>();

        try {
            // Get the list of trusted packages from a resource, which allows vendor overlays.
            String[] trustedPackages = mContext.getResources().getStringArray(
                    R.array.trusted_search_providers);
            if (trustedPackages == null) {
                Log.w(TAG, "Could not load list of trusted search providers, trusting none");
                return trusted;
            }
            for (String trustedPackage : trustedPackages) {
                trusted.add(trustedPackage);
            }
            return trusted;
        } catch (Resources.NotFoundException ex) {
            Log.w(TAG, "Could not load list of trusted search providers, trusting none");
            return trusted;
        }
    }

    /**
     * Checks if we trust the given source not to be spammy.
     */
    public synchronized boolean isTrustedSource(String packageName) {
        if (mTrustedPackages == null) {
            mTrustedPackages = loadTrustedPackages();
        }
        return mTrustedPackages.contains(packageName);
    }

    /**
     * The maximum number of suggestions to promote.
     */
    public int getMaxPromotedSuggestions() {
        return MAX_PROMOTED_SUGGESTIONS;
    }

    /**
     * The number of results to ask each source for.
     */
    public int getMaxResultsPerSource() {
        return MAX_RESULTS_PER_SOURCE;
    }

    /**
     * The timeout for querying each source, in milliseconds.
     */
    public long getSourceTimeoutMillis() {
        return SOURCE_TIMEOUT_MILLIS;
    }

    /**
     * The maximum thread pool size for the query thread pool.
     */
    public int getQueryThreadMaxPoolSize(){
        return QUERY_THREAD_MAX_POOL_SIZE;
    }

    /**
     * The keep-alive time for the query thread pool, in millisseconds.
     */
    public long getQueryThreadKeepAliveMillis() {
        return QUERY_THREAD_KEEPALIVE_MILLIS;
    }

    /**
     * The priority of query threads.
     *
     * @return A thread priority, as defined in {@link Process}.
     */
    public int getQueryThreadPriority() {
        return QUERY_THREAD_PRIORITY;
    }

    /**
     * The maximum delay with which a new source result is published, in milliseconds.
     */
    public long getSourceResultPublishDelayMillis() {
        return SOURCE_RESULT_PUBLISH_DELAY_MILLIS;
    }


    public long getMaxStatAgeMillis(){
        return MAX_STAT_AGE_MILLIS;
    }

    public long getMaxSourceEventAgeMillis(){
        return MAX_SOURCE_EVENT_AGE_MILLIS;
    }

    public int getMinImpressionsForSourceRanking(){
        return MIN_IMPRESSIONS_FOR_SOURCE_RANKING;
    }

    public int getMinClicksForSourceRanking(){
        return MIN_CLICKS_FOR_SOURCE_RANKING;
    }

    public int getMaxShortcutsReturned(){
        return MAX_SHORTCUTS_RETURNED;
    }

    public long getThreadStartDelayMillis() {
        return THREAD_START_DELAY_MILLIS;
    }

}