diff options
Diffstat (limited to 'java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoder.java')
| -rw-r--r-- | java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoder.java | 824 |
1 files changed, 109 insertions, 715 deletions
diff --git a/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoder.java b/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoder.java index 5e3d6d22d..b86dfe552 100644 --- a/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoder.java +++ b/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoder.java @@ -17,35 +17,23 @@ package com.android.inputmethod.latin.makedict; import com.android.inputmethod.annotations.UsedForTesting; -import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader; -import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions; -import com.android.inputmethod.latin.makedict.FusionDictionary.CharGroup; -import com.android.inputmethod.latin.makedict.FusionDictionary.PtNodeArray; -import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString; -import com.android.inputmethod.latin.makedict.decoder.HeaderReaderInterface; +import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.CharEncoding; +import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.DictBuffer; +import com.android.inputmethod.latin.makedict.decoder.HeaderReader; +import com.android.inputmethod.latin.utils.ByteArrayDictBuffer; import com.android.inputmethod.latin.utils.JniUtils; -import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; +import java.io.RandomAccessFile; import java.nio.ByteBuffer; import java.nio.channels.FileChannel; -import java.util.ArrayList; -import java.util.Arrays; import java.util.HashMap; -import java.util.Map; -import java.util.TreeMap; -/** - * Decodes binary files for a FusionDictionary. - * - * All the methods in this class are static. - */ -public final class BinaryDictDecoder { - - private static final boolean DBG = MakedictLog.DBG; +@UsedForTesting +public class BinaryDictDecoder implements HeaderReader { static { JniUtils.loadNativeLibrary(); @@ -54,742 +42,148 @@ public final class BinaryDictDecoder { // TODO: implement something sensical instead of just a phony method private static native int doNothing(); - private BinaryDictDecoder() { - // This utility class is not publicly instantiable. - } - - private static final int MAX_JUMPS = 12; - - @UsedForTesting - public interface FusionDictionaryBufferInterface { - public int readUnsignedByte(); - public int readUnsignedShort(); - public int readUnsignedInt24(); - public int readInt(); - public int position(); - public void position(int newPosition); - public void put(final byte b); - public int limit(); - @UsedForTesting - public int capacity(); - } - - public static final class ByteBufferWrapper implements FusionDictionaryBufferInterface { - private ByteBuffer mBuffer; - - public ByteBufferWrapper(final ByteBuffer buffer) { - mBuffer = buffer; - } - - @Override - public int readUnsignedByte() { - return mBuffer.get() & 0xFF; - } - - @Override - public int readUnsignedShort() { - return mBuffer.getShort() & 0xFFFF; - } - - @Override - public int readUnsignedInt24() { - final int retval = readUnsignedByte(); - return (retval << 16) + readUnsignedShort(); - } - - @Override - public int readInt() { - return mBuffer.getInt(); - } - - @Override - public int position() { - return mBuffer.position(); - } - - @Override - public void position(int newPos) { - mBuffer.position(newPos); - } - - @Override - public void put(final byte b) { - mBuffer.put(b); - } - - @Override - public int limit() { - return mBuffer.limit(); - } - - @Override - public int capacity() { - return mBuffer.capacity(); - } + public interface DictionaryBufferFactory { + public DictBuffer getDictionaryBuffer(final File file) + throws FileNotFoundException, IOException; } /** - * A class grouping utility function for our specific character encoding. + * Creates DictionaryBuffer using a ByteBuffer + * + * This class uses less memory than DictionaryBufferFromByteArrayFactory, + * but doesn't perform as fast. + * When operating on a big dictionary, this class is preferred. */ - static final class CharEncoding { - private static final int MINIMAL_ONE_BYTE_CHARACTER_VALUE = 0x20; - private static final int MAXIMAL_ONE_BYTE_CHARACTER_VALUE = 0xFF; - - /** - * Helper method to find out whether this code fits on one byte - */ - private static boolean fitsOnOneByte(final int character) { - return character >= MINIMAL_ONE_BYTE_CHARACTER_VALUE - && character <= MAXIMAL_ONE_BYTE_CHARACTER_VALUE; - } - - /** - * Compute the size of a character given its character code. - * - * Char format is: - * 1 byte = bbbbbbbb match - * case 000xxxxx: xxxxx << 16 + next byte << 8 + next byte - * else: if 00011111 (= 0x1F) : this is the terminator. This is a relevant choice because - * unicode code points range from 0 to 0x10FFFF, so any 3-byte value starting with - * 00011111 would be outside unicode. - * else: iso-latin-1 code - * This allows for the whole unicode range to be encoded, including chars outside of - * the BMP. Also everything in the iso-latin-1 charset is only 1 byte, except control - * characters which should never happen anyway (and still work, but take 3 bytes). - * - * @param character the character code. - * @return the size in binary encoded-form, either 1 or 3 bytes. - */ - static int getCharSize(final int character) { - // See char encoding in FusionDictionary.java - if (fitsOnOneByte(character)) return 1; - if (FormatSpec.INVALID_CHARACTER == character) return 1; - return 3; - } - - /** - * Compute the byte size of a character array. - */ - static int getCharArraySize(final int[] chars) { - int size = 0; - for (int character : chars) size += getCharSize(character); - return size; - } - - /** - * Writes a char array to a byte buffer. - * - * @param codePoints the code point array to write. - * @param buffer the byte buffer to write to. - * @param index the index in buffer to write the character array to. - * @return the index after the last character. - */ - static int writeCharArray(final int[] codePoints, final byte[] buffer, int index) { - for (int codePoint : codePoints) { - if (1 == getCharSize(codePoint)) { - buffer[index++] = (byte)codePoint; - } else { - buffer[index++] = (byte)(0xFF & (codePoint >> 16)); - buffer[index++] = (byte)(0xFF & (codePoint >> 8)); - buffer[index++] = (byte)(0xFF & codePoint); - } - } - return index; - } - - /** - * Writes a string with our character format to a byte buffer. - * - * This will also write the terminator byte. - * - * @param buffer the byte buffer to write to. - * @param origin the offset to write from. - * @param word the string to write. - * @return the size written, in bytes. - */ - static int writeString(final byte[] buffer, final int origin, - final String word) { - final int length = word.length(); - int index = origin; - for (int i = 0; i < length; i = word.offsetByCodePoints(i, 1)) { - final int codePoint = word.codePointAt(i); - if (1 == getCharSize(codePoint)) { - buffer[index++] = (byte)codePoint; - } else { - buffer[index++] = (byte)(0xFF & (codePoint >> 16)); - buffer[index++] = (byte)(0xFF & (codePoint >> 8)); - buffer[index++] = (byte)(0xFF & codePoint); - } - } - buffer[index++] = FormatSpec.GROUP_CHARACTERS_TERMINATOR; - return index - origin; - } - - /** - * Writes a string with our character format to a ByteArrayOutputStream. - * - * This will also write the terminator byte. - * - * @param buffer the ByteArrayOutputStream to write to. - * @param word the string to write. - */ - static void writeString(final ByteArrayOutputStream buffer, final String word) { - final int length = word.length(); - for (int i = 0; i < length; i = word.offsetByCodePoints(i, 1)) { - final int codePoint = word.codePointAt(i); - if (1 == getCharSize(codePoint)) { - buffer.write((byte) codePoint); - } else { - buffer.write((byte) (0xFF & (codePoint >> 16))); - buffer.write((byte) (0xFF & (codePoint >> 8))); - buffer.write((byte) (0xFF & codePoint)); - } - } - buffer.write(FormatSpec.GROUP_CHARACTERS_TERMINATOR); - } - - /** - * Reads a string from a buffer. This is the converse of the above method. - */ - static String readString(final FusionDictionaryBufferInterface buffer) { - final StringBuilder s = new StringBuilder(); - int character = readChar(buffer); - while (character != FormatSpec.INVALID_CHARACTER) { - s.appendCodePoint(character); - character = readChar(buffer); - } - return s.toString(); - } - - /** - * Reads a character from the buffer. - * - * This follows the character format documented earlier in this source file. - * - * @param buffer the buffer, positioned over an encoded character. - * @return the character code. - */ - static int readChar(final FusionDictionaryBufferInterface buffer) { - int character = buffer.readUnsignedByte(); - if (!fitsOnOneByte(character)) { - if (FormatSpec.GROUP_CHARACTERS_TERMINATOR == character) { - return FormatSpec.INVALID_CHARACTER; - } - character <<= 16; - character += buffer.readUnsignedShort(); - } - return character; - } - } - - // Input methods: Read a binary dictionary to memory. - // readDictionaryBinary is the public entry point for them. - - static int readChildrenAddress(final FusionDictionaryBufferInterface buffer, - final int optionFlags, final FormatOptions options) { - if (options.mSupportsDynamicUpdate) { - final int address = buffer.readUnsignedInt24(); - if (address == 0) return FormatSpec.NO_CHILDREN_ADDRESS; - if ((address & FormatSpec.MSB24) != 0) { - return -(address & FormatSpec.SINT24_MAX); - } else { - return address; - } - } - int address; - switch (optionFlags & FormatSpec.MASK_GROUP_ADDRESS_TYPE) { - case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_ONEBYTE: - return buffer.readUnsignedByte(); - case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_TWOBYTES: - return buffer.readUnsignedShort(); - case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_THREEBYTES: - return buffer.readUnsignedInt24(); - case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_NOADDRESS: - default: - return FormatSpec.NO_CHILDREN_ADDRESS; - } - } - - static int readParentAddress(final FusionDictionaryBufferInterface buffer, - final FormatOptions formatOptions) { - if (BinaryDictIOUtils.supportsDynamicUpdate(formatOptions)) { - final int parentAddress = buffer.readUnsignedInt24(); - final int sign = ((parentAddress & FormatSpec.MSB24) != 0) ? -1 : 1; - return sign * (parentAddress & FormatSpec.SINT24_MAX); - } else { - return FormatSpec.NO_PARENT_ADDRESS; - } - } - - private static final int[] CHARACTER_BUFFER = new int[FormatSpec.MAX_WORD_LENGTH]; - public static CharGroupInfo readCharGroup(final FusionDictionaryBufferInterface buffer, - final int originalGroupAddress, final FormatOptions options) { - int addressPointer = originalGroupAddress; - final int flags = buffer.readUnsignedByte(); - ++addressPointer; - - final int parentAddress = readParentAddress(buffer, options); - if (BinaryDictIOUtils.supportsDynamicUpdate(options)) { - addressPointer += 3; - } - - final int characters[]; - if (0 != (flags & FormatSpec.FLAG_HAS_MULTIPLE_CHARS)) { - int index = 0; - int character = CharEncoding.readChar(buffer); - addressPointer += CharEncoding.getCharSize(character); - while (-1 != character) { - // FusionDictionary is making sure that the length of the word is smaller than - // MAX_WORD_LENGTH. - // So we'll never write past the end of CHARACTER_BUFFER. - CHARACTER_BUFFER[index++] = character; - character = CharEncoding.readChar(buffer); - addressPointer += CharEncoding.getCharSize(character); - } - characters = Arrays.copyOfRange(CHARACTER_BUFFER, 0, index); - } else { - final int character = CharEncoding.readChar(buffer); - addressPointer += CharEncoding.getCharSize(character); - characters = new int[] { character }; - } - final int frequency; - if (0 != (FormatSpec.FLAG_IS_TERMINAL & flags)) { - ++addressPointer; - frequency = buffer.readUnsignedByte(); - } else { - frequency = CharGroup.NOT_A_TERMINAL; - } - int childrenAddress = readChildrenAddress(buffer, flags, options); - if (childrenAddress != FormatSpec.NO_CHILDREN_ADDRESS) { - childrenAddress += addressPointer; - } - addressPointer += BinaryDictIOUtils.getChildrenAddressSize(flags, options); - ArrayList<WeightedString> shortcutTargets = null; - if (0 != (flags & FormatSpec.FLAG_HAS_SHORTCUT_TARGETS)) { - final int pointerBefore = buffer.position(); - shortcutTargets = new ArrayList<WeightedString>(); - buffer.readUnsignedShort(); // Skip the size - while (true) { - final int targetFlags = buffer.readUnsignedByte(); - final String word = CharEncoding.readString(buffer); - shortcutTargets.add(new WeightedString(word, - targetFlags & FormatSpec.FLAG_ATTRIBUTE_FREQUENCY)); - if (0 == (targetFlags & FormatSpec.FLAG_ATTRIBUTE_HAS_NEXT)) break; - } - addressPointer += buffer.position() - pointerBefore; - } - ArrayList<PendingAttribute> bigrams = null; - if (0 != (flags & FormatSpec.FLAG_HAS_BIGRAMS)) { - bigrams = new ArrayList<PendingAttribute>(); - int bigramCount = 0; - while (bigramCount++ < FormatSpec.MAX_BIGRAMS_IN_A_GROUP) { - final int bigramFlags = buffer.readUnsignedByte(); - ++addressPointer; - final int sign = 0 == (bigramFlags & FormatSpec.FLAG_ATTRIBUTE_OFFSET_NEGATIVE) - ? 1 : -1; - int bigramAddress = addressPointer; - switch (bigramFlags & FormatSpec.MASK_ATTRIBUTE_ADDRESS_TYPE) { - case FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE: - bigramAddress += sign * buffer.readUnsignedByte(); - addressPointer += 1; - break; - case FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES: - bigramAddress += sign * buffer.readUnsignedShort(); - addressPointer += 2; - break; - case FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES: - final int offset = (buffer.readUnsignedByte() << 16) - + buffer.readUnsignedShort(); - bigramAddress += sign * offset; - addressPointer += 3; - break; - default: - throw new RuntimeException("Has bigrams with no address"); + public static final class DictionaryBufferFromReadOnlyByteBufferFactory + implements DictionaryBufferFactory { + @Override + public DictBuffer getDictionaryBuffer(final File file) + throws FileNotFoundException, IOException { + FileInputStream inStream = null; + ByteBuffer buffer = null; + try { + inStream = new FileInputStream(file); + buffer = inStream.getChannel().map(FileChannel.MapMode.READ_ONLY, + 0, file.length()); + } finally { + if (inStream != null) { + inStream.close(); } - bigrams.add(new PendingAttribute(bigramFlags & FormatSpec.FLAG_ATTRIBUTE_FREQUENCY, - bigramAddress)); - if (0 == (bigramFlags & FormatSpec.FLAG_ATTRIBUTE_HAS_NEXT)) break; } - if (bigramCount >= FormatSpec.MAX_BIGRAMS_IN_A_GROUP) { - MakedictLog.d("too many bigrams in a group."); + if (buffer != null) { + return new BinaryDictDecoderUtils.ByteBufferDictBuffer(buffer); } - } - return new CharGroupInfo(originalGroupAddress, addressPointer, flags, characters, frequency, - parentAddress, childrenAddress, shortcutTargets, bigrams); - } - - /** - * Reads and returns the char group count out of a buffer and forwards the pointer. - */ - public static int readCharGroupCount(final FusionDictionaryBufferInterface buffer) { - final int msb = buffer.readUnsignedByte(); - if (FormatSpec.MAX_CHARGROUPS_FOR_ONE_BYTE_CHARGROUP_COUNT >= msb) { - return msb; - } else { - return ((FormatSpec.MAX_CHARGROUPS_FOR_ONE_BYTE_CHARGROUP_COUNT & msb) << 8) - + buffer.readUnsignedByte(); + return null; } } /** - * Finds, as a string, the word at the address passed as an argument. + * Creates DictionaryBuffer using a byte array * - * @param buffer the buffer to read from. - * @param headerSize the size of the header. - * @param address the address to seek. - * @param formatOptions file format options. - * @return the word with its frequency, as a weighted string. + * This class performs faster than other classes, but consumes more memory. + * When operating on a small dictionary, this class is preferred. */ - /* package for tests */ static WeightedString getWordAtAddress( - final FusionDictionaryBufferInterface buffer, final int headerSize, final int address, - final FormatOptions formatOptions) { - final WeightedString result; - final int originalPointer = buffer.position(); - buffer.position(address); - - if (BinaryDictIOUtils.supportsDynamicUpdate(formatOptions)) { - result = getWordAtAddressWithParentAddress(buffer, headerSize, address, formatOptions); - } else { - result = getWordAtAddressWithoutParentAddress(buffer, headerSize, address, - formatOptions); - } - - buffer.position(originalPointer); - return result; - } - - @SuppressWarnings("unused") - private static WeightedString getWordAtAddressWithParentAddress( - final FusionDictionaryBufferInterface buffer, final int headerSize, final int address, - final FormatOptions options) { - int currentAddress = address; - int frequency = Integer.MIN_VALUE; - final StringBuilder builder = new StringBuilder(); - // the length of the path from the root to the leaf is limited by MAX_WORD_LENGTH - for (int count = 0; count < FormatSpec.MAX_WORD_LENGTH; ++count) { - CharGroupInfo currentInfo; - int loopCounter = 0; - do { - buffer.position(currentAddress + headerSize); - currentInfo = readCharGroup(buffer, currentAddress, options); - if (BinaryDictIOUtils.isMovedGroup(currentInfo.mFlags, options)) { - currentAddress = currentInfo.mParentAddress + currentInfo.mOriginalAddress; - } - if (DBG && loopCounter++ > MAX_JUMPS) { - MakedictLog.d("Too many jumps - probably a bug"); - } - } while (BinaryDictIOUtils.isMovedGroup(currentInfo.mFlags, options)); - if (Integer.MIN_VALUE == frequency) frequency = currentInfo.mFrequency; - builder.insert(0, - new String(currentInfo.mCharacters, 0, currentInfo.mCharacters.length)); - if (currentInfo.mParentAddress == FormatSpec.NO_PARENT_ADDRESS) break; - currentAddress = currentInfo.mParentAddress + currentInfo.mOriginalAddress; - } - return new WeightedString(builder.toString(), frequency); - } - - private static WeightedString getWordAtAddressWithoutParentAddress( - final FusionDictionaryBufferInterface buffer, final int headerSize, final int address, - final FormatOptions options) { - buffer.position(headerSize); - final int count = readCharGroupCount(buffer); - int groupOffset = BinaryDictIOUtils.getGroupCountSize(count); - final StringBuilder builder = new StringBuilder(); - WeightedString result = null; - - CharGroupInfo last = null; - for (int i = count - 1; i >= 0; --i) { - CharGroupInfo info = readCharGroup(buffer, groupOffset, options); - groupOffset = info.mEndAddress; - if (info.mOriginalAddress == address) { - builder.append(new String(info.mCharacters, 0, info.mCharacters.length)); - result = new WeightedString(builder.toString(), info.mFrequency); - break; // and return - } - if (BinaryDictIOUtils.hasChildrenAddress(info.mChildrenAddress)) { - if (info.mChildrenAddress > address) { - if (null == last) continue; - builder.append(new String(last.mCharacters, 0, last.mCharacters.length)); - buffer.position(last.mChildrenAddress + headerSize); - i = readCharGroupCount(buffer); - groupOffset = last.mChildrenAddress + BinaryDictIOUtils.getGroupCountSize(i); - last = null; - continue; + public static final class DictionaryBufferFromByteArrayFactory + implements DictionaryBufferFactory { + @Override + public DictBuffer getDictionaryBuffer(final File file) + throws FileNotFoundException, IOException { + FileInputStream inStream = null; + try { + inStream = new FileInputStream(file); + final byte[] array = new byte[(int) file.length()]; + inStream.read(array); + return new ByteArrayDictBuffer(array); + } finally { + if (inStream != null) { + inStream.close(); } - last = info; - } - if (0 == i && BinaryDictIOUtils.hasChildrenAddress(last.mChildrenAddress)) { - builder.append(new String(last.mCharacters, 0, last.mCharacters.length)); - buffer.position(last.mChildrenAddress + headerSize); - i = readCharGroupCount(buffer); - groupOffset = last.mChildrenAddress + BinaryDictIOUtils.getGroupCountSize(i); - last = null; - continue; } } - return result; } /** - * Reads a single node array from a buffer. + * Creates DictionaryBuffer using a writable ByteBuffer and a RandomAccessFile. * - * This methods reads the file at the current position. A node array is fully expected to start - * at the current position. - * This will recursively read other node arrays into the structure, populating the reverse - * maps on the fly and using them to keep track of already read nodes. - * - * @param buffer the buffer, correctly positioned at the start of a node array. - * @param headerSize the size, in bytes, of the file header. - * @param reverseNodeArrayMap a mapping from addresses to already read node arrays. - * @param reverseGroupMap a mapping from addresses to already read character groups. - * @param options file format options. - * @return the read node array with all his children already read. + * This class doesn't perform as fast as other classes, + * but this class is the only option available for destructive operations (insert or delete) + * on a dictionary. */ - private static PtNodeArray readNodeArray(final FusionDictionaryBufferInterface buffer, - final int headerSize, final Map<Integer, PtNodeArray> reverseNodeArrayMap, - final Map<Integer, CharGroup> reverseGroupMap, final FormatOptions options) - throws IOException { - final ArrayList<CharGroup> nodeArrayContents = new ArrayList<CharGroup>(); - final int nodeArrayOrigin = buffer.position() - headerSize; - - do { // Scan the linked-list node. - final int nodeArrayHeadPosition = buffer.position() - headerSize; - final int count = readCharGroupCount(buffer); - int groupOffset = nodeArrayHeadPosition + BinaryDictIOUtils.getGroupCountSize(count); - for (int i = count; i > 0; --i) { // Scan the array of CharGroup. - CharGroupInfo info = readCharGroup(buffer, groupOffset, options); - if (BinaryDictIOUtils.isMovedGroup(info.mFlags, options)) continue; - ArrayList<WeightedString> shortcutTargets = info.mShortcutTargets; - ArrayList<WeightedString> bigrams = null; - if (null != info.mBigrams) { - bigrams = new ArrayList<WeightedString>(); - for (PendingAttribute bigram : info.mBigrams) { - final WeightedString word = getWordAtAddress( - buffer, headerSize, bigram.mAddress, options); - final int reconstructedFrequency = - reconstructBigramFrequency(word.mFrequency, bigram.mFrequency); - bigrams.add(new WeightedString(word.mWord, reconstructedFrequency)); - } - } - if (BinaryDictIOUtils.hasChildrenAddress(info.mChildrenAddress)) { - PtNodeArray children = reverseNodeArrayMap.get(info.mChildrenAddress); - if (null == children) { - final int currentPosition = buffer.position(); - buffer.position(info.mChildrenAddress + headerSize); - children = readNodeArray( - buffer, headerSize, reverseNodeArrayMap, reverseGroupMap, options); - buffer.position(currentPosition); - } - nodeArrayContents.add( - new CharGroup(info.mCharacters, shortcutTargets, bigrams, - info.mFrequency, - 0 != (info.mFlags & FormatSpec.FLAG_IS_NOT_A_WORD), - 0 != (info.mFlags & FormatSpec.FLAG_IS_BLACKLISTED), children)); - } else { - nodeArrayContents.add( - new CharGroup(info.mCharacters, shortcutTargets, bigrams, - info.mFrequency, - 0 != (info.mFlags & FormatSpec.FLAG_IS_NOT_A_WORD), - 0 != (info.mFlags & FormatSpec.FLAG_IS_BLACKLISTED))); + @UsedForTesting + public static final class DictionaryBufferFromWritableByteBufferFactory + implements DictionaryBufferFactory { + @Override + public DictBuffer getDictionaryBuffer(final File file) + throws FileNotFoundException, IOException { + RandomAccessFile raFile = null; + ByteBuffer buffer = null; + try { + raFile = new RandomAccessFile(file, "rw"); + buffer = raFile.getChannel().map(FileChannel.MapMode.READ_WRITE, 0, file.length()); + } finally { + if (raFile != null) { + raFile.close(); } - groupOffset = info.mEndAddress; } - - // reach the end of the array. - if (options.mSupportsDynamicUpdate) { - final int nextAddress = buffer.readUnsignedInt24(); - if (nextAddress >= 0 && nextAddress < buffer.limit()) { - buffer.position(nextAddress); - } else { - break; - } + if (buffer != null) { + return new BinaryDictDecoderUtils.ByteBufferDictBuffer(buffer); } - } while (options.mSupportsDynamicUpdate && - buffer.position() != FormatSpec.NO_FORWARD_LINK_ADDRESS); - - final PtNodeArray nodeArray = new PtNodeArray(nodeArrayContents); - nodeArray.mCachedAddressBeforeUpdate = nodeArrayOrigin; - nodeArray.mCachedAddressAfterUpdate = nodeArrayOrigin; - reverseNodeArrayMap.put(nodeArray.mCachedAddressAfterUpdate, nodeArray); - return nodeArray; - } - - /** - * Helper function to get the binary format version from the header. - * @throws IOException - */ - private static int getFormatVersion(final FusionDictionaryBufferInterface buffer) - throws IOException { - final int magic = buffer.readInt(); - if (FormatSpec.MAGIC_NUMBER == magic) return buffer.readUnsignedShort(); - return FormatSpec.NOT_A_VERSION_NUMBER; - } - - /** - * Helper function to get and validate the binary format version. - * @throws UnsupportedFormatException - * @throws IOException - */ - static int checkFormatVersion(final FusionDictionaryBufferInterface buffer) - throws IOException, UnsupportedFormatException { - final int version = getFormatVersion(buffer); - if (version < FormatSpec.MINIMUM_SUPPORTED_VERSION - || version > FormatSpec.MAXIMUM_SUPPORTED_VERSION) { - throw new UnsupportedFormatException("This file has version " + version - + ", but this implementation does not support versions above " - + FormatSpec.MAXIMUM_SUPPORTED_VERSION); + return null; } - return version; } - /** - * Reads a header from a buffer. - * @param headerReader the header reader - * @throws IOException - * @throws UnsupportedFormatException - */ - public static FileHeader readHeader(final HeaderReaderInterface headerReader) - throws IOException, UnsupportedFormatException { - final int version = headerReader.readVersion(); - final int optionsFlags = headerReader.readOptionFlags(); - - final int headerSize = headerReader.readHeaderSize(); - - if (headerSize < 0) { - throw new UnsupportedFormatException("header size can't be negative."); - } + private final File mDictionaryBinaryFile; + private DictBuffer mDictBuffer; - final HashMap<String, String> attributes = headerReader.readAttributes(headerSize); + public BinaryDictDecoder(final File file) { + mDictionaryBinaryFile = file; + mDictBuffer = null; + } - final FileHeader header = new FileHeader(headerSize, - new FusionDictionary.DictionaryOptions(attributes, - 0 != (optionsFlags & FormatSpec.GERMAN_UMLAUT_PROCESSING_FLAG), - 0 != (optionsFlags & FormatSpec.FRENCH_LIGATURE_PROCESSING_FLAG)), - new FormatOptions(version, - 0 != (optionsFlags & FormatSpec.SUPPORTS_DYNAMIC_UPDATE))); - return header; + public void openDictBuffer(final DictionaryBufferFactory factory) + throws FileNotFoundException, IOException { + mDictBuffer = factory.getDictionaryBuffer(mDictionaryBinaryFile); } - /** - * Reads options from a buffer and populate a map with their contents. - * - * The buffer is read at the current position, so the caller must take care the pointer - * is in the right place before calling this. - */ - public static void populateOptions(final FusionDictionaryBufferInterface buffer, - final int headerSize, final HashMap<String, String> options) { - while (buffer.position() < headerSize) { - final String key = CharEncoding.readString(buffer); - final String value = CharEncoding.readString(buffer); - options.put(key, value); - } + public DictBuffer getDictBuffer() { + return mDictBuffer; } - /** - * Reads a buffer and returns the memory representation of the dictionary. - * - * This high-level method takes a buffer and reads its contents, populating a - * FusionDictionary structure. The optional dict argument is an existing dictionary to - * which words from the buffer should be added. If it is null, a new dictionary is created. - * - * @param reader the reader. - * @param dict an optional dictionary to add words to, or null. - * @return the created (or merged) dictionary. - */ @UsedForTesting - public static FusionDictionary readDictionaryBinary(final BinaryDictReader reader, - final FusionDictionary dict) throws FileNotFoundException, IOException, - UnsupportedFormatException { - - // if the buffer has not been opened, open the buffer with bytebuffer. - if (reader.getBuffer() == null) reader.openBuffer( - new BinaryDictReader.FusionDictionaryBufferFromByteBufferFactory()); - if (reader.getBuffer() == null) { - MakedictLog.e("Cannot open the buffer"); - } - - // Read header - final FileHeader fileHeader = readHeader(reader); - - Map<Integer, PtNodeArray> reverseNodeArrayMapping = new TreeMap<Integer, PtNodeArray>(); - Map<Integer, CharGroup> reverseGroupMapping = new TreeMap<Integer, CharGroup>(); - final PtNodeArray root = readNodeArray(reader.getBuffer(), fileHeader.mHeaderSize, - reverseNodeArrayMapping, reverseGroupMapping, fileHeader.mFormatOptions); - - FusionDictionary newDict = new FusionDictionary(root, fileHeader.mDictionaryOptions); - if (null != dict) { - for (final Word w : dict) { - if (w.mIsBlacklistEntry) { - newDict.addBlacklistEntry(w.mWord, w.mShortcutTargets, w.mIsNotAWord); - } else { - newDict.add(w.mWord, w.mFrequency, w.mShortcutTargets, w.mIsNotAWord); - } - } - for (final Word w : dict) { - // By construction a binary dictionary may not have bigrams pointing to - // words that are not also registered as unigrams so we don't have to avoid - // them explicitly here. - for (final WeightedString bigram : w.mBigrams) { - newDict.setBigram(w.mWord, bigram.mWord, bigram.mFrequency); - } - } - } + public DictBuffer openAndGetDictBuffer( + final DictionaryBufferFactory factory) + throws FileNotFoundException, IOException { + openDictBuffer(factory); + return getDictBuffer(); + } - return newDict; + // The implementation of HeaderReader + @Override + public int readVersion() throws IOException, UnsupportedFormatException { + return BinaryDictDecoderUtils.checkFormatVersion(mDictBuffer); } - /** - * Helper method to pass a file name instead of a File object to isBinaryDictionary. - */ - public static boolean isBinaryDictionary(final String filename) { - final File file = new File(filename); - return isBinaryDictionary(file); + @Override + public int readOptionFlags() { + return mDictBuffer.readUnsignedShort(); } - /** - * Basic test to find out whether the file is a binary dictionary or not. - * - * Concretely this only tests the magic number. - * - * @param file The file to test. - * @return true if it's a binary dictionary, false otherwise - */ - public static boolean isBinaryDictionary(final File file) { - FileInputStream inStream = null; - try { - inStream = new FileInputStream(file); - final ByteBuffer buffer = inStream.getChannel().map( - FileChannel.MapMode.READ_ONLY, 0, file.length()); - final int version = getFormatVersion(new ByteBufferWrapper(buffer)); - return (version >= FormatSpec.MINIMUM_SUPPORTED_VERSION - && version <= FormatSpec.MAXIMUM_SUPPORTED_VERSION); - } catch (FileNotFoundException e) { - return false; - } catch (IOException e) { - return false; - } finally { - if (inStream != null) { - try { - inStream.close(); - } catch (IOException e) { - // do nothing - } - } - } + @Override + public int readHeaderSize() { + return mDictBuffer.readInt(); } - /** - * Calculate bigram frequency from compressed value - * - * @param unigramFrequency - * @param bigramFrequency compressed frequency - * @return approximate bigram frequency - */ - public static int reconstructBigramFrequency(final int unigramFrequency, - final int bigramFrequency) { - final float stepSize = (FormatSpec.MAX_TERMINAL_FREQUENCY - unigramFrequency) - / (1.5f + FormatSpec.MAX_BIGRAM_FREQUENCY); - final float resultFreqFloat = unigramFrequency + stepSize * (bigramFrequency + 1.0f); - return (int)resultFreqFloat; + @Override + public HashMap<String, String> readAttributes(final int headerSize) { + final HashMap<String, String> attributes = new HashMap<String, String>(); + while (mDictBuffer.position() < headerSize) { + // We can avoid infinite loop here since mFusionDictonary.position() is always increased + // by calling CharEncoding.readString. + final String key = CharEncoding.readString(mDictBuffer); + final String value = CharEncoding.readString(mDictBuffer); + attributes.put(key, value); + } + mDictBuffer.position(headerSize); + return attributes; } } |