LatinIME/java/src/com/android/inputmethod/latin/Utils.java

439 lines
17 KiB
Java

/*
* Copyright (C) 2010 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.inputmethod.latin;
import android.inputmethodservice.InputMethodService;
import android.os.AsyncTask;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Process;
import android.text.format.DateUtils;
import android.util.Log;
import android.view.inputmethod.InputMethodInfo;
import android.view.inputmethod.InputMethodManager;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.Date;
public class Utils {
private static final String TAG = Utils.class.getSimpleName();
private static final int MINIMUM_SAFETY_NET_CHAR_LENGTH = 4;
private static boolean DBG = LatinImeLogger.sDBG;
/**
* Cancel an {@link AsyncTask}.
*
* @param mayInterruptIfRunning <tt>true</tt> if the thread executing this
* task should be interrupted; otherwise, in-progress tasks are allowed
* to complete.
*/
public static void cancelTask(AsyncTask<?, ?, ?> task, boolean mayInterruptIfRunning) {
if (task != null && task.getStatus() != AsyncTask.Status.FINISHED) {
task.cancel(mayInterruptIfRunning);
}
}
public static class GCUtils {
private static final String TAG = "GCUtils";
public static final int GC_TRY_COUNT = 2;
// GC_TRY_LOOP_MAX is used for the hard limit of GC wait,
// GC_TRY_LOOP_MAX should be greater than GC_TRY_COUNT.
public static final int GC_TRY_LOOP_MAX = 5;
private static final long GC_INTERVAL = DateUtils.SECOND_IN_MILLIS;
private static GCUtils sInstance = new GCUtils();
private int mGCTryCount = 0;
public static GCUtils getInstance() {
return sInstance;
}
public void reset() {
mGCTryCount = 0;
}
public boolean tryGCOrWait(String metaData, Throwable t) {
if (mGCTryCount == 0) {
System.gc();
}
if (++mGCTryCount > GC_TRY_COUNT) {
LatinImeLogger.logOnException(metaData, t);
return false;
} else {
try {
Thread.sleep(GC_INTERVAL);
return true;
} catch (InterruptedException e) {
Log.e(TAG, "Sleep was interrupted.");
LatinImeLogger.logOnException(metaData, t);
return false;
}
}
}
}
public static boolean hasMultipleEnabledIMEsOrSubtypes(InputMethodManager imm) {
return imm.getEnabledInputMethodList().size() > 1
// imm.getEnabledInputMethodSubtypeList(null, false) will return the current IME's enabled
// input method subtype (The current IME should be LatinIME.)
|| imm.getEnabledInputMethodSubtypeList(null, false).size() > 1;
}
public static String getInputMethodId(InputMethodManager imm, String packageName) {
for (final InputMethodInfo imi : imm.getEnabledInputMethodList()) {
if (imi.getPackageName().equals(packageName))
return imi.getId();
}
throw new RuntimeException("Can not find input method id for " + packageName);
}
public static boolean shouldBlockedBySafetyNetForAutoCorrection(SuggestedWords suggestions,
Suggest suggest) {
// Safety net for auto correction.
// Actually if we hit this safety net, it's actually a bug.
if (suggestions.size() <= 1 || suggestions.mTypedWordValid) return false;
// If user selected aggressive auto correction mode, there is no need to use the safety
// net.
if (suggest.isAggressiveAutoCorrectionMode()) return false;
CharSequence typedWord = suggestions.getWord(0);
// If the length of typed word is less than MINIMUM_SAFETY_NET_CHAR_LENGTH,
// we should not use net because relatively edit distance can be big.
if (typedWord.length() < MINIMUM_SAFETY_NET_CHAR_LENGTH) return false;
CharSequence candidateWord = suggestions.getWord(1);
final int typedWordLength = typedWord.length();
final int maxEditDistanceOfNativeDictionary = typedWordLength < 5 ? 2 : typedWordLength / 2;
final int distance = Utils.editDistance(typedWord, candidateWord);
if (DBG) {
Log.d(TAG, "Autocorrected edit distance = " + distance
+ ", " + maxEditDistanceOfNativeDictionary);
}
if (distance > maxEditDistanceOfNativeDictionary) {
Log.w(TAG, "(Error) The edit distance of this correction exceeds limit. "
+ "Turning off auto-correction.");
return true;
} else {
return false;
}
}
/* package */ static class RingCharBuffer {
private static RingCharBuffer sRingCharBuffer = new RingCharBuffer();
private static final char PLACEHOLDER_DELIMITER_CHAR = '\uFFFC';
private static final int INVALID_COORDINATE = -2;
/* package */ static final int BUFSIZE = 20;
private InputMethodService mContext;
private boolean mEnabled = false;
private boolean mUsabilityStudy = false;
private int mEnd = 0;
/* package */ int mLength = 0;
private char[] mCharBuf = new char[BUFSIZE];
private int[] mXBuf = new int[BUFSIZE];
private int[] mYBuf = new int[BUFSIZE];
private RingCharBuffer() {
// Intentional empty constructor for singleton.
}
public static RingCharBuffer getInstance() {
return sRingCharBuffer;
}
public static RingCharBuffer init(InputMethodService context, boolean enabled,
boolean usabilityStudy) {
sRingCharBuffer.mContext = context;
sRingCharBuffer.mEnabled = enabled || usabilityStudy;
sRingCharBuffer.mUsabilityStudy = usabilityStudy;
UsabilityStudyLogUtils.getInstance().init(context);
return sRingCharBuffer;
}
private int normalize(int in) {
int ret = in % BUFSIZE;
return ret < 0 ? ret + BUFSIZE : ret;
}
public void push(char c, int x, int y) {
if (!mEnabled) return;
if (mUsabilityStudy) {
UsabilityStudyLogUtils.getInstance().writeChar(c, x, y);
}
mCharBuf[mEnd] = c;
mXBuf[mEnd] = x;
mYBuf[mEnd] = y;
mEnd = normalize(mEnd + 1);
if (mLength < BUFSIZE) {
++mLength;
}
}
public char pop() {
if (mLength < 1) {
return PLACEHOLDER_DELIMITER_CHAR;
} else {
mEnd = normalize(mEnd - 1);
--mLength;
return mCharBuf[mEnd];
}
}
public char getLastChar() {
if (mLength < 1) {
return PLACEHOLDER_DELIMITER_CHAR;
} else {
return mCharBuf[normalize(mEnd - 1)];
}
}
public int getPreviousX(char c, int back) {
int index = normalize(mEnd - 2 - back);
if (mLength <= back
|| Character.toLowerCase(c) != Character.toLowerCase(mCharBuf[index])) {
return INVALID_COORDINATE;
} else {
return mXBuf[index];
}
}
public int getPreviousY(char c, int back) {
int index = normalize(mEnd - 2 - back);
if (mLength <= back
|| Character.toLowerCase(c) != Character.toLowerCase(mCharBuf[index])) {
return INVALID_COORDINATE;
} else {
return mYBuf[index];
}
}
public String getLastString() {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < mLength; ++i) {
char c = mCharBuf[normalize(mEnd - 1 - i)];
if (!((LatinIME)mContext).isWordSeparator(c)) {
sb.append(c);
} else {
break;
}
}
return sb.reverse().toString();
}
public void reset() {
mLength = 0;
}
}
public static int editDistance(CharSequence s, CharSequence t) {
if (s == null || t == null) {
throw new IllegalArgumentException("editDistance: Arguments should not be null.");
}
final int sl = s.length();
final int tl = t.length();
int[][] dp = new int [sl + 1][tl + 1];
for (int i = 0; i <= sl; i++) {
dp[i][0] = i;
}
for (int j = 0; j <= tl; j++) {
dp[0][j] = j;
}
for (int i = 0; i < sl; ++i) {
for (int j = 0; j < tl; ++j) {
if (Character.toLowerCase(s.charAt(i)) == Character.toLowerCase(t.charAt(j))) {
dp[i + 1][j + 1] = dp[i][j];
} else {
dp[i + 1][j + 1] = 1 + Math.min(dp[i][j],
Math.min(dp[i + 1][j], dp[i][j + 1]));
}
}
}
return dp[sl][tl];
}
// In dictionary.cpp, getSuggestion() method,
// suggestion scores are computed using the below formula.
// original score (called 'frequency')
// := pow(mTypedLetterMultiplier (this is defined 2),
// (the number of matched characters between typed word and suggested word))
// * (individual word's score which defined in the unigram dictionary,
// and this score is defined in range [0, 255].)
// * (when before.length() == after.length(),
// mFullWordMultiplier (this is defined 2))
// So, maximum original score is pow(2, before.length()) * 255 * 2
// So, we can normalize original score by dividing this value.
private static final int MAX_INITIAL_SCORE = 255;
private static final int TYPED_LETTER_MULTIPLIER = 2;
private static final int FULL_WORD_MULTIPLYER = 2;
public static double calcNormalizedScore(CharSequence before, CharSequence after, int score) {
final int beforeLength = before.length();
final int afterLength = after.length();
if (beforeLength == 0 || afterLength == 0) return 0;
final int distance = editDistance(before, after);
// If afterLength < beforeLength, the algorithm is suggesting a word by excessive character
// correction.
final double maximumScore = MAX_INITIAL_SCORE
* Math.pow(TYPED_LETTER_MULTIPLIER, Math.min(beforeLength, afterLength))
* FULL_WORD_MULTIPLYER;
// add a weight based on edit distance.
// distance <= max(afterLength, beforeLength) == afterLength,
// so, 0 <= distance / afterLength <= 1
final double weight = 1.0 - (double) distance / afterLength;
return (score / maximumScore) * weight;
}
public static class UsabilityStudyLogUtils {
private static final String TAG = "UsabilityStudyLogUtils";
private static final String FILENAME = "log.txt";
private static final UsabilityStudyLogUtils sInstance =
new UsabilityStudyLogUtils();
private final Handler mLoggingHandler;
private File mFile;
private File mDirectory;
private InputMethodService mIms;
private PrintWriter mWriter;
private final Date mDate;
private final SimpleDateFormat mDateFormat;
private UsabilityStudyLogUtils() {
mDate = new Date();
mDateFormat = new SimpleDateFormat("dd MMM HH:mm:ss.SSS");
HandlerThread handlerThread = new HandlerThread("UsabilityStudyLogUtils logging task",
Process.THREAD_PRIORITY_BACKGROUND);
handlerThread.start();
mLoggingHandler = new Handler(handlerThread.getLooper());
}
public static UsabilityStudyLogUtils getInstance() {
return sInstance;
}
public void init(InputMethodService ims) {
mIms = ims;
mDirectory = ims.getFilesDir();
}
private void createLogFileIfNotExist() {
if ((mFile == null || !mFile.exists())
&& (mDirectory != null && mDirectory.exists())) {
try {
mWriter = getPrintWriter(mDirectory, FILENAME, false);
} catch (IOException e) {
Log.e(TAG, "Can't create log file.");
}
}
}
public void writeBackSpace() {
UsabilityStudyLogUtils.getInstance().write("<backspace>\t0\t0");
}
public void writeChar(char c, int x, int y) {
String inputChar = String.valueOf(c);
switch (c) {
case '\n':
inputChar = "<enter>";
break;
case '\t':
inputChar = "<tab>";
break;
case ' ':
inputChar = "<space>";
break;
}
UsabilityStudyLogUtils.getInstance().write(inputChar + "\t" + x + "\t" + y);
LatinImeLogger.onPrintAllUsabilityStudyLogs();
}
public void write(final String log) {
mLoggingHandler.post(new Runnable() {
@Override
public void run() {
createLogFileIfNotExist();
final long currentTime = System.currentTimeMillis();
mDate.setTime(currentTime);
final String printString = String.format("%s\t%d\t%s\n",
mDateFormat.format(mDate), currentTime, log);
if (LatinImeLogger.sDBG) {
Log.d(TAG, "Write: " + log);
}
mWriter.print(printString);
}
});
}
public void printAll() {
mLoggingHandler.post(new Runnable() {
@Override
public void run() {
mWriter.flush();
StringBuilder sb = new StringBuilder();
BufferedReader br = getBufferedReader();
String line;
try {
while ((line = br.readLine()) != null) {
sb.append('\n');
sb.append(line);
}
} catch (IOException e) {
Log.e(TAG, "Can't read log file.");
} finally {
if (LatinImeLogger.sDBG) {
Log.d(TAG, "output all logs\n" + sb.toString());
}
mIms.getCurrentInputConnection().commitText(sb.toString(), 0);
try {
br.close();
} catch (IOException e) {
// ignore.
}
}
}
});
}
public void clearAll() {
mLoggingHandler.post(new Runnable() {
@Override
public void run() {
if (mFile != null && mFile.exists()) {
if (LatinImeLogger.sDBG) {
Log.d(TAG, "Delete log file.");
}
mFile.delete();
mWriter.close();
}
}
});
}
private BufferedReader getBufferedReader() {
createLogFileIfNotExist();
try {
return new BufferedReader(new FileReader(mFile));
} catch (FileNotFoundException e) {
return null;
}
}
private PrintWriter getPrintWriter(
File dir, String filename, boolean renew) throws IOException {
mFile = new File(dir, filename);
if (mFile.exists()) {
if (renew) {
mFile.delete();
}
}
return new PrintWriter(new FileOutputStream(mFile), true /* autoFlush */);
}
}
}