| /* |
| * Copyright (C) 2007-2014 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.view.inputmethod; |
| |
| import android.annotation.UnsupportedAppUsage; |
| import android.os.Parcel; |
| import android.util.Slog; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.ByteArrayOutputStream; |
| import java.util.List; |
| import java.util.zip.GZIPInputStream; |
| import java.util.zip.GZIPOutputStream; |
| |
| /** |
| * An array-like container that stores multiple instances of {@link InputMethodSubtype}. |
| * |
| * <p>This container is designed to reduce the risk of {@link TransactionTooLargeException} |
| * when one or more instancess of {@link InputMethodInfo} are transferred through IPC. |
| * Basically this class does following three tasks.</p> |
| * <ul> |
| * <li>Applying compression for the marshalled data</li> |
| * <li>Lazily unmarshalling objects</li> |
| * <li>Caching the marshalled data when appropriate</li> |
| * </ul> |
| * |
| * @hide |
| */ |
| public class InputMethodSubtypeArray { |
| private final static String TAG = "InputMethodSubtypeArray"; |
| |
| /** |
| * Create a new instance of {@link InputMethodSubtypeArray} from an existing list of |
| * {@link InputMethodSubtype}. |
| * |
| * @param subtypes A list of {@link InputMethodSubtype} from which |
| * {@link InputMethodSubtypeArray} will be created. |
| */ |
| @UnsupportedAppUsage |
| public InputMethodSubtypeArray(final List<InputMethodSubtype> subtypes) { |
| if (subtypes == null) { |
| mCount = 0; |
| return; |
| } |
| mCount = subtypes.size(); |
| mInstance = subtypes.toArray(new InputMethodSubtype[mCount]); |
| } |
| |
| /** |
| * Unmarshall an instance of {@link InputMethodSubtypeArray} from a given {@link Parcel} |
| * object. |
| * |
| * @param source A {@link Parcel} object from which {@link InputMethodSubtypeArray} will be |
| * unmarshalled. |
| */ |
| public InputMethodSubtypeArray(final Parcel source) { |
| mCount = source.readInt(); |
| if (mCount > 0) { |
| mDecompressedSize = source.readInt(); |
| mCompressedData = source.createByteArray(); |
| } |
| } |
| |
| /** |
| * Marshall the instance into a given {@link Parcel} object. |
| * |
| * <p>This methods may take a bit additional time to compress data lazily when called |
| * first time.</p> |
| * |
| * @param source A {@link Parcel} object to which {@link InputMethodSubtypeArray} will be |
| * marshalled. |
| */ |
| public void writeToParcel(final Parcel dest) { |
| if (mCount == 0) { |
| dest.writeInt(mCount); |
| return; |
| } |
| |
| byte[] compressedData = mCompressedData; |
| int decompressedSize = mDecompressedSize; |
| if (compressedData == null && decompressedSize == 0) { |
| synchronized (mLockObject) { |
| compressedData = mCompressedData; |
| decompressedSize = mDecompressedSize; |
| if (compressedData == null && decompressedSize == 0) { |
| final byte[] decompressedData = marshall(mInstance); |
| compressedData = compress(decompressedData); |
| if (compressedData == null) { |
| decompressedSize = -1; |
| Slog.i(TAG, "Failed to compress data."); |
| } else { |
| decompressedSize = decompressedData.length; |
| } |
| mDecompressedSize = decompressedSize; |
| mCompressedData = compressedData; |
| } |
| } |
| } |
| |
| if (compressedData != null && decompressedSize > 0) { |
| dest.writeInt(mCount); |
| dest.writeInt(decompressedSize); |
| dest.writeByteArray(compressedData); |
| } else { |
| Slog.i(TAG, "Unexpected state. Behaving as an empty array."); |
| dest.writeInt(0); |
| } |
| } |
| |
| /** |
| * Return {@link InputMethodSubtype} specified with the given index. |
| * |
| * <p>This methods may take a bit additional time to decompress data lazily when called |
| * first time.</p> |
| * |
| * @param index The index of {@link InputMethodSubtype}. |
| */ |
| public InputMethodSubtype get(final int index) { |
| if (index < 0 || mCount <= index) { |
| throw new ArrayIndexOutOfBoundsException(); |
| } |
| InputMethodSubtype[] instance = mInstance; |
| if (instance == null) { |
| synchronized (mLockObject) { |
| instance = mInstance; |
| if (instance == null) { |
| final byte[] decompressedData = |
| decompress(mCompressedData, mDecompressedSize); |
| // Clear the compressed data until {@link #getMarshalled()} is called. |
| mCompressedData = null; |
| mDecompressedSize = 0; |
| if (decompressedData != null) { |
| instance = unmarshall(decompressedData); |
| } else { |
| Slog.e(TAG, "Failed to decompress data. Returns null as fallback."); |
| instance = new InputMethodSubtype[mCount]; |
| } |
| mInstance = instance; |
| } |
| } |
| } |
| return instance[index]; |
| } |
| |
| /** |
| * Return the number of {@link InputMethodSubtype} objects. |
| */ |
| public int getCount() { |
| return mCount; |
| } |
| |
| private final Object mLockObject = new Object(); |
| private final int mCount; |
| |
| private volatile InputMethodSubtype[] mInstance; |
| private volatile byte[] mCompressedData; |
| private volatile int mDecompressedSize; |
| |
| private static byte[] marshall(final InputMethodSubtype[] array) { |
| Parcel parcel = null; |
| try { |
| parcel = Parcel.obtain(); |
| parcel.writeTypedArray(array, 0); |
| return parcel.marshall(); |
| } finally { |
| if (parcel != null) { |
| parcel.recycle(); |
| parcel = null; |
| } |
| } |
| } |
| |
| private static InputMethodSubtype[] unmarshall(final byte[] data) { |
| Parcel parcel = null; |
| try { |
| parcel = Parcel.obtain(); |
| parcel.unmarshall(data, 0, data.length); |
| parcel.setDataPosition(0); |
| return parcel.createTypedArray(InputMethodSubtype.CREATOR); |
| } finally { |
| if (parcel != null) { |
| parcel.recycle(); |
| parcel = null; |
| } |
| } |
| } |
| |
| private static byte[] compress(final byte[] data) { |
| try (final ByteArrayOutputStream resultStream = new ByteArrayOutputStream(); |
| final GZIPOutputStream zipper = new GZIPOutputStream(resultStream)) { |
| zipper.write(data); |
| zipper.finish(); |
| return resultStream.toByteArray(); |
| } catch(Exception e) { |
| Slog.e(TAG, "Failed to compress the data.", e); |
| return null; |
| } |
| } |
| |
| private static byte[] decompress(final byte[] data, final int expectedSize) { |
| try (final ByteArrayInputStream inputStream = new ByteArrayInputStream(data); |
| final GZIPInputStream unzipper = new GZIPInputStream(inputStream)) { |
| final byte [] result = new byte[expectedSize]; |
| int totalReadBytes = 0; |
| while (totalReadBytes < result.length) { |
| final int restBytes = result.length - totalReadBytes; |
| final int readBytes = unzipper.read(result, totalReadBytes, restBytes); |
| if (readBytes < 0) { |
| break; |
| } |
| totalReadBytes += readBytes; |
| } |
| if (expectedSize != totalReadBytes) { |
| return null; |
| } |
| return result; |
| } catch(Exception e) { |
| Slog.e(TAG, "Failed to decompress the data.", e); |
| return null; |
| } |
| } |
| } |