tests/UiBench/src/com/android/test/uibench/TextUtils.java

/*
 * Copyright (C) 2015 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.test.uibench;

import android.icu.text.UnicodeSet;
import android.icu.text.UnicodeSetIterator;

import java.util.ArrayList;
import java.util.Random;

public class TextUtils {
    private static final int STRING_COUNT = 200;
    private static final int SIMPLE_STRING_LENGTH = 10;  // in code points

    private static String[] UnicodeSetToArray(UnicodeSet set) {
        final UnicodeSetIterator iterator = new UnicodeSetIterator(set);
        final ArrayList<String> out = new ArrayList<>(set.size());
        while (iterator.next()) {
            out.add(iterator.getString());
        }
        return out.toArray(new String[out.size()]);
    }

    /**
     * Create word of random assortment of lower/upper case letters
     */
    private static String randomWord(Random random, int length) {
        String result = "";
        for (int j = 0; j < length; j++) {
            // add random letter
            int base = random.nextInt(2) == 0 ? 'A' : 'a';
            result += (char)(random.nextInt(26) + base);
        }
        return result;
    }

    /**
     * Create word from a random assortment of a given set of codepoints, given as strings.
     */
    private static String randomWordFromStringSet(Random random, int length, String[] stringSet) {
        final StringBuilder sb = new StringBuilder(length);
        final int setLength = stringSet.length;
        for (int j = 0; j < length; j++) {
            sb.append(stringSet[random.nextInt(setLength)]);
        }
        return sb.toString();
    }

    public static String[] buildSimpleStringList() {
        return buildSimpleStringList(SIMPLE_STRING_LENGTH);
    }

    public static String[] buildEmojiStringList() {
        return buildEmojiStringList(SIMPLE_STRING_LENGTH);
    }

    public static String[] buildHanStringList() {
        return buildHanStringList(SIMPLE_STRING_LENGTH);
    }

    public static String[] buildLongStringList() {
        return buildLongStringList(SIMPLE_STRING_LENGTH);
    }

    public static String[] buildSimpleStringList(int stringLength) {
        String[] strings = new String[STRING_COUNT];
        Random random = new Random(0);
        for (int i = 0; i < strings.length; i++) {
            strings[i] = randomWord(random, stringLength);
        }
        return strings;
    }

    private static String[] buildStringListFromUnicodeSet(int stringLength, UnicodeSet set) {
        final String[] strings = new String[STRING_COUNT];
        final Random random = new Random(0);
        final String[] stringSet = UnicodeSetToArray(set);
        for (int i = 0; i < strings.length; i++) {
            strings[i] = randomWordFromStringSet(random, stringLength, stringSet);
        }
        return strings;
    }

    public static String[] buildEmojiStringList(int stringLength) {
        return buildStringListFromUnicodeSet(stringLength, new UnicodeSet("[:emoji:]"));
    }

    public static String[] buildHanStringList(int stringLength) {
        return buildStringListFromUnicodeSet(stringLength, new UnicodeSet("[\\u4E00-\\u9FA0]"));
    }

    public static String[] buildLongStringList(int stringLength) {
        final int WORD_COUNT = 100;
        final String[] strings = new String[STRING_COUNT];
        final Random random = new Random(0);
        for (int i = 0; i < strings.length; i++) {
            final StringBuilder sb = new StringBuilder((stringLength + 1) * WORD_COUNT);
            for (int j = 0; j < WORD_COUNT; ++j) {
                if (j != 0) {
                    sb.append(' ');
                }
                sb.append(randomWord(random, stringLength));
            }
            strings[i] = sb.toString();
        }
        return strings;
    }

    // a small number of strings reused frequently, expected to hit
    // in the word-granularity text layout cache
    static final String[] CACHE_HIT_STRINGS = new String[] {
            "a",
            "small",
            "number",
            "of",
            "strings",
            "reused",
            "frequently"
    };

    private static final int WORDS_IN_PARAGRAPH = 150;

    // misses are fairly long 'words' to ensure they miss
    private static final int PARAGRAPH_MISS_MIN_LENGTH = 4;
    private static final int PARAGRAPH_MISS_MAX_LENGTH = 9;

    static String[] buildParagraphListWithHitPercentage(int hitPercentage) {
        if (hitPercentage < 0 || hitPercentage > 100) throw new IllegalArgumentException();

        String[] strings = new String[STRING_COUNT];
        Random random = new Random(0);
        for (int i = 0; i < strings.length; i++) {
            String result = "";
            for (int word = 0; word < WORDS_IN_PARAGRAPH; word++) {
                if (word != 0) {
                    result += " ";
                }
                if (random.nextInt(100) < hitPercentage) {
                    // add a common word, which is very likely to hit in the cache
                    result += CACHE_HIT_STRINGS[random.nextInt(CACHE_HIT_STRINGS.length)];
                } else {
                    // construct a random word, which will *most likely* miss
                    int length = PARAGRAPH_MISS_MIN_LENGTH;
                    length += random.nextInt(PARAGRAPH_MISS_MAX_LENGTH - PARAGRAPH_MISS_MIN_LENGTH);

                    result += randomWord(random, length);
                }
            }
            strings[i] = result;
        }

        return strings;
    }
}