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Diffstat (limited to 'java/src/com/android/inputmethod/latin/makedict/Ver4DictDecoder.java')
| -rw-r--r-- | java/src/com/android/inputmethod/latin/makedict/Ver4DictDecoder.java | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/java/src/com/android/inputmethod/latin/makedict/Ver4DictDecoder.java b/java/src/com/android/inputmethod/latin/makedict/Ver4DictDecoder.java new file mode 100644 index 000000000..36c5a2720 --- /dev/null +++ b/java/src/com/android/inputmethod/latin/makedict/Ver4DictDecoder.java @@ -0,0 +1,259 @@ +/* + * Copyright (C) 2013 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.makedict; + +import com.android.inputmethod.annotations.UsedForTesting; +import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.CharEncoding; +import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.DictBuffer; +import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader; +import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions; +import com.android.inputmethod.latin.makedict.FusionDictionary.PtNode; +import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString; + +import android.util.Log; + +import java.io.File; +import java.io.FileNotFoundException; +import java.io.IOException; +import java.util.ArrayList; +import java.util.Arrays; + +/** + * An implementation of binary dictionary decoder for version 4 binary dictionary. + */ +@UsedForTesting +public class Ver4DictDecoder extends DictDecoder { + private static final String TAG = Ver4DictDecoder.class.getSimpleName(); + + private static final int FILETYPE_TRIE = 1; + private static final int FILETYPE_FREQUENCY = 2; + + private final File mDictDirectory; + private final DictionaryBufferFactory mBufferFactory; + private DictBuffer mDictBuffer; + private DictBuffer mFrequencyBuffer; + + @UsedForTesting + /* package */ Ver4DictDecoder(final File dictDirectory, final int factoryFlag) { + mDictDirectory = dictDirectory; + mDictBuffer = mFrequencyBuffer = null; + + if ((factoryFlag & MASK_DICTBUFFER) == USE_READONLY_BYTEBUFFER) { + mBufferFactory = new DictionaryBufferFromReadOnlyByteBufferFactory(); + } else if ((factoryFlag & MASK_DICTBUFFER) == USE_BYTEARRAY) { + mBufferFactory = new DictionaryBufferFromByteArrayFactory(); + } else if ((factoryFlag & MASK_DICTBUFFER) == USE_WRITABLE_BYTEBUFFER) { + mBufferFactory = new DictionaryBufferFromWritableByteBufferFactory(); + } else { + mBufferFactory = new DictionaryBufferFromReadOnlyByteBufferFactory(); + } + } + + @UsedForTesting + /* package */ Ver4DictDecoder(final File dictDirectory, final DictionaryBufferFactory factory) { + mDictDirectory = dictDirectory; + mBufferFactory = factory; + mDictBuffer = mFrequencyBuffer = null; + } + + private File getFile(final int fileType) { + if (fileType == FILETYPE_TRIE) { + return new File(mDictDirectory, + mDictDirectory.getName() + FormatSpec.TRIE_FILE_EXTENSION); + } else if (fileType == FILETYPE_FREQUENCY) { + return new File(mDictDirectory, + mDictDirectory.getName() + FormatSpec.FREQ_FILE_EXTENSION); + } else { + throw new RuntimeException("Unsupported kind of file : " + fileType); + } + } + + @Override + public void openDictBuffer() throws FileNotFoundException, IOException { + final String filename = mDictDirectory.getName(); + mDictBuffer = mBufferFactory.getDictionaryBuffer(getFile(FILETYPE_TRIE)); + mFrequencyBuffer = mBufferFactory.getDictionaryBuffer(getFile(FILETYPE_FREQUENCY)); + } + + @Override + public boolean isDictBufferOpen() { + return mDictBuffer != null; + } + + /* package */ DictBuffer getDictBuffer() { + return mDictBuffer; + } + + @Override + public FileHeader readHeader() throws IOException, UnsupportedFormatException { + if (mDictBuffer == null) { + openDictBuffer(); + } + final FileHeader header = super.readHeader(mDictBuffer); + final int version = header.mFormatOptions.mVersion; + if (version != 4) { + throw new UnsupportedFormatException("File header has a wrong version : " + version); + } + return header; + } + + protected static class PtNodeReader extends DictDecoder.PtNodeReader { + protected static int readFrequency(final DictBuffer frequencyBuffer, final int terminalId) { + frequencyBuffer.position(terminalId * FormatSpec.FREQUENCY_AND_FLAGS_SIZE + 1); + return frequencyBuffer.readUnsignedByte(); + } + + protected static int readTerminalId(final DictBuffer dictBuffer) { + return dictBuffer.readInt(); + } + } + + // TODO: Make this buffer thread safe. + // TODO: Support words longer than FormatSpec.MAX_WORD_LENGTH. + private final int[] mCharacterBuffer = new int[FormatSpec.MAX_WORD_LENGTH]; + @Override + public PtNodeInfo readPtNode(int ptNodePos, FormatOptions options) { + int addressPointer = ptNodePos; + final int flags = PtNodeReader.readPtNodeOptionFlags(mDictBuffer); + addressPointer += FormatSpec.PTNODE_FLAGS_SIZE; + + final int parentAddress = PtNodeReader.readParentAddress(mDictBuffer, options); + if (BinaryDictIOUtils.supportsDynamicUpdate(options)) { + addressPointer += FormatSpec.PARENT_ADDRESS_SIZE; + } + + final int characters[]; + if (0 != (flags & FormatSpec.FLAG_HAS_MULTIPLE_CHARS)) { + int index = 0; + int character = CharEncoding.readChar(mDictBuffer); + addressPointer += CharEncoding.getCharSize(character); + while (FormatSpec.INVALID_CHARACTER != character + && index < FormatSpec.MAX_WORD_LENGTH) { + mCharacterBuffer[index++] = character; + character = CharEncoding.readChar(mDictBuffer); + addressPointer += CharEncoding.getCharSize(character); + } + characters = Arrays.copyOfRange(mCharacterBuffer, 0, index); + } else { + final int character = CharEncoding.readChar(mDictBuffer); + addressPointer += CharEncoding.getCharSize(character); + characters = new int[] { character }; + } + final int terminalId; + if (0 != (FormatSpec.FLAG_IS_TERMINAL & flags)) { + terminalId = PtNodeReader.readTerminalId(mDictBuffer); + addressPointer += FormatSpec.PTNODE_TERMINAL_ID_SIZE; + } else { + terminalId = PtNode.NOT_A_TERMINAL; + } + + final int frequency; + if (0 != (FormatSpec.FLAG_IS_TERMINAL & flags)) { + frequency = PtNodeReader.readFrequency(mFrequencyBuffer, terminalId); + } else { + frequency = PtNode.NOT_A_TERMINAL; + } + int childrenAddress = PtNodeReader.readChildrenAddress(mDictBuffer, flags, options); + if (childrenAddress != FormatSpec.NO_CHILDREN_ADDRESS) { + childrenAddress += addressPointer; + } + addressPointer += BinaryDictIOUtils.getChildrenAddressSize(flags, options); + final ArrayList<WeightedString> shortcutTargets; + if (0 != (flags & FormatSpec.FLAG_HAS_SHORTCUT_TARGETS)) { + // readShortcut will add shortcuts to shortcutTargets. + shortcutTargets = new ArrayList<WeightedString>(); + addressPointer += PtNodeReader.readShortcut(mDictBuffer, shortcutTargets); + } else { + shortcutTargets = null; + } + + final ArrayList<PendingAttribute> bigrams; + if (0 != (flags & FormatSpec.FLAG_HAS_BIGRAMS)) { + bigrams = new ArrayList<PendingAttribute>(); + addressPointer += PtNodeReader.readBigramAddresses(mDictBuffer, bigrams, + addressPointer); + if (bigrams.size() >= FormatSpec.MAX_BIGRAMS_IN_A_PTNODE) { + MakedictLog.d("too many bigrams in a node."); + } + } else { + bigrams = null; + } + return new PtNodeInfo(ptNodePos, addressPointer, flags, characters, frequency, + parentAddress, childrenAddress, shortcutTargets, bigrams); + } + + private void deleteDictFiles() { + final File[] files = mDictDirectory.listFiles(); + for (int i = 0; i < files.length; ++i) { + files[i].delete(); + } + } + + @Override + public FusionDictionary readDictionaryBinary(final FusionDictionary dict, + final boolean deleteDictIfBroken) + throws FileNotFoundException, IOException, UnsupportedFormatException { + if (mDictBuffer == null) { + openDictBuffer(); + } + try { + return BinaryDictDecoderUtils.readDictionaryBinary(this, dict); + } catch (IOException e) { + Log.e(TAG, "The dictionary " + mDictDirectory.getName() + " is broken.", e); + if (deleteDictIfBroken) { + deleteDictFiles(); + } + throw e; + } catch (UnsupportedFormatException e) { + Log.e(TAG, "The dictionary " + mDictDirectory.getName() + " is broken.", e); + if (deleteDictIfBroken) { + deleteDictFiles(); + } + throw e; + } + } + + @Override + public void setPosition(int newPos) { + mDictBuffer.position(newPos); + } + + @Override + public int getPosition() { + return mDictBuffer.position(); + } + + @Override + public int readPtNodeCount() { + return BinaryDictDecoderUtils.readPtNodeCount(mDictBuffer); + } + + @Override + public boolean readAndFollowForwardLink() { + final int nextAddress = mDictBuffer.readUnsignedInt24(); + if (nextAddress >= 0 && nextAddress < mDictBuffer.limit()) { + mDictBuffer.position(nextAddress); + return true; + } + return false; + } + + @Override + public boolean hasNextPtNodeArray() { + return mDictBuffer.position() != FormatSpec.NO_FORWARD_LINK_ADDRESS; + } +} |