/* * Copyright (C) 2011 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.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.DictionaryOptions; import com.android.inputmethod.latin.makedict.FusionDictionary.Node; import com.android.inputmethod.latin.makedict.FusionDictionary.WeightedString; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.OutputStream; import java.nio.ByteBuffer; import java.nio.channels.FileChannel; import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.TreeMap; /** * Reads and writes XML files for a FusionDictionary. * * All the methods in this class are static. */ public final class BinaryDictInputOutput { private static final boolean DBG = MakedictLog.DBG; // Arbitrary limit to how much passes we consider address size compression should // terminate in. At the time of this writing, our largest dictionary completes // compression in five passes. // If the number of passes exceeds this number, makedict bails with an exception on // suspicion that a bug might be causing an infinite loop. private static final int MAX_PASSES = 24; 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(); 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(); } } /** * A class grouping utility function for our specific character encoding. */ 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. */ private 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. */ private 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. */ private 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. */ private 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. */ private 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; } } /** * Compute the binary size of the character array. * * If only one character, this is the size of this character. If many, it's the sum of their * sizes + 1 byte for the terminator. * * @param characters the character array * @return the size of the char array, including the terminator if any */ static int getGroupCharactersSize(final int[] characters) { int size = CharEncoding.getCharArraySize(characters); if (characters.length > 1) size += FormatSpec.GROUP_TERMINATOR_SIZE; return size; } /** * Compute the binary size of the character array in a group * * If only one character, this is the size of this character. If many, it's the sum of their * sizes + 1 byte for the terminator. * * @param group the group * @return the size of the char array, including the terminator if any */ private static int getGroupCharactersSize(final CharGroup group) { return getGroupCharactersSize(group.mChars); } /** * Compute the binary size of the group count * @param count the group count * @return the size of the group count, either 1 or 2 bytes. */ public static int getGroupCountSize(final int count) { if (FormatSpec.MAX_CHARGROUPS_FOR_ONE_BYTE_CHARGROUP_COUNT >= count) { return 1; } else if (FormatSpec.MAX_CHARGROUPS_IN_A_NODE >= count) { return 2; } else { throw new RuntimeException("Can't have more than " + FormatSpec.MAX_CHARGROUPS_IN_A_NODE + " groups in a node (found " + count + ")"); } } /** * Compute the binary size of the group count for a node * @param node the node * @return the size of the group count, either 1 or 2 bytes. */ private static int getGroupCountSize(final Node node) { return getGroupCountSize(node.mData.size()); } /** * Compute the size of a shortcut in bytes. */ private static int getShortcutSize(final WeightedString shortcut) { int size = FormatSpec.GROUP_ATTRIBUTE_FLAGS_SIZE; final String word = shortcut.mWord; final int length = word.length(); for (int i = 0; i < length; i = word.offsetByCodePoints(i, 1)) { final int codePoint = word.codePointAt(i); size += CharEncoding.getCharSize(codePoint); } size += FormatSpec.GROUP_TERMINATOR_SIZE; return size; } /** * Compute the size of a shortcut list in bytes. * * This is known in advance and does not change according to position in the file * like address lists do. */ static int getShortcutListSize(final ArrayList shortcutList) { if (null == shortcutList) return 0; int size = FormatSpec.GROUP_SHORTCUT_LIST_SIZE_SIZE; for (final WeightedString shortcut : shortcutList) { size += getShortcutSize(shortcut); } return size; } /** * Compute the maximum size of a CharGroup, assuming 3-byte addresses for everything. * * @param group the CharGroup to compute the size of. * @param options file format options. * @return the maximum size of the group. */ private static int getCharGroupMaximumSize(final CharGroup group, final FormatOptions options) { int size = getGroupHeaderSize(group, options); // If terminal, one byte for the frequency if (group.isTerminal()) size += FormatSpec.GROUP_FREQUENCY_SIZE; size += FormatSpec.GROUP_MAX_ADDRESS_SIZE; // For children address size += getShortcutListSize(group.mShortcutTargets); if (null != group.mBigrams) { size += (FormatSpec.GROUP_ATTRIBUTE_FLAGS_SIZE + FormatSpec.GROUP_ATTRIBUTE_MAX_ADDRESS_SIZE) * group.mBigrams.size(); } return size; } /** * Compute the maximum size of a node, assuming 3-byte addresses for everything, and caches * it in the 'actualSize' member of the node. * * @param node the node to compute the maximum size of. * @param options file format options. */ private static void setNodeMaximumSize(final Node node, final FormatOptions options) { int size = getGroupCountSize(node); for (CharGroup g : node.mData) { final int groupSize = getCharGroupMaximumSize(g, options); g.mCachedSize = groupSize; size += groupSize; } if (options.mSupportsDynamicUpdate) { size += FormatSpec.FORWARD_LINK_ADDRESS_SIZE; } node.mCachedSize = size; } /** * Helper method to hide the actual value of the no children address. */ public static boolean hasChildrenAddress(final int address) { return FormatSpec.NO_CHILDREN_ADDRESS != address; } /** * Helper method to check whether the group is moved. */ public static boolean isMovedGroup(final int flags, final FormatOptions options) { return options.mSupportsDynamicUpdate && ((flags & FormatSpec.MASK_GROUP_ADDRESS_TYPE) == FormatSpec.FLAG_IS_MOVED); } /** * Helper method to check whether the group is deleted. */ public static boolean isDeletedGroup(final int flags, final FormatOptions formatOptions) { return formatOptions.mSupportsDynamicUpdate && ((flags & FormatSpec.MASK_GROUP_ADDRESS_TYPE) == FormatSpec.FLAG_IS_DELETED); } /** * Helper method to check whether the dictionary can be updated dynamically. */ public static boolean supportsDynamicUpdate(final FormatOptions options) { return options.mVersion >= FormatSpec.FIRST_VERSION_WITH_DYNAMIC_UPDATE && options.mSupportsDynamicUpdate; } /** * Compute the size of the header (flag + [parent address] + characters size) of a CharGroup. * * @param group the group of which to compute the size of the header * @param options file format options. */ private static int getGroupHeaderSize(final CharGroup group, final FormatOptions options) { if (supportsDynamicUpdate(options)) { return FormatSpec.GROUP_FLAGS_SIZE + FormatSpec.PARENT_ADDRESS_SIZE + getGroupCharactersSize(group); } else { return FormatSpec.GROUP_FLAGS_SIZE + getGroupCharactersSize(group); } } private static final int UINT8_MAX = 0xFF; private static final int UINT16_MAX = 0xFFFF; private static final int UINT24_MAX = 0xFFFFFF; /** * Compute the size, in bytes, that an address will occupy. * * This can be used either for children addresses (which are always positive) or for * attribute, which may be positive or negative but * store their sign bit separately. * * @param address the address * @return the byte size. */ static int getByteSize(final int address) { assert(address <= UINT24_MAX); if (!hasChildrenAddress(address)) { return 0; } else if (Math.abs(address) <= UINT8_MAX) { return 1; } else if (Math.abs(address) <= UINT16_MAX) { return 2; } else { return 3; } } private static final int SINT24_MAX = 0x7FFFFF; private static final int MSB8 = 0x80; private static final int MSB24 = 0x800000; // End utility methods. // This method is responsible for finding a nice ordering of the nodes that favors run-time // cache performance and dictionary size. /* package for tests */ static ArrayList flattenTree(final Node root) { final int treeSize = FusionDictionary.countCharGroups(root); MakedictLog.i("Counted nodes : " + treeSize); final ArrayList flatTree = new ArrayList(treeSize); return flattenTreeInner(flatTree, root); } private static ArrayList flattenTreeInner(final ArrayList list, final Node node) { // Removing the node is necessary if the tails are merged, because we would then // add the same node several times when we only want it once. A number of places in // the code also depends on any node being only once in the list. // Merging tails can only be done if there are no attributes. Searching for attributes // in LatinIME code depends on a total breadth-first ordering, which merging tails // breaks. If there are no attributes, it should be fine (and reduce the file size) // to merge tails, and removing the node from the list would be necessary. However, // we don't merge tails because breaking the breadth-first ordering would result in // extreme overhead at bigram lookup time (it would make the search function O(n) instead // of the current O(log(n)), where n=number of nodes in the dictionary which is pretty // high). // If no nodes are ever merged, we can't have the same node twice in the list, hence // searching for duplicates in unnecessary. It is also very performance consuming, // since `list' is an ArrayList so it's an O(n) operation that runs on all nodes, making // this simple list.remove operation O(n*n) overall. On Android this overhead is very // high. // For future reference, the code to remove duplicate is a simple : list.remove(node); list.add(node); final ArrayList branches = node.mData; final int nodeSize = branches.size(); for (CharGroup group : branches) { if (null != group.mChildren) flattenTreeInner(list, group.mChildren); } return list; } /** * Finds the absolute address of a word in the dictionary. * * @param dict the dictionary in which to search. * @param word the word we are searching for. * @return the word address. If it is not found, an exception is thrown. */ private static int findAddressOfWord(final FusionDictionary dict, final String word) { return FusionDictionary.findWordInTree(dict.mRoot, word).mCachedAddress; } /** * Computes the actual node size, based on the cached addresses of the children nodes. * * Each node stores its tentative address. During dictionary address computing, these * are not final, but they can be used to compute the node size (the node size depends * on the address of the children because the number of bytes necessary to store an * address depends on its numeric value. The return value indicates whether the node * contents (as in, any of the addresses stored in the cache fields) have changed with * respect to their previous value. * * @param node the node to compute the size of. * @param dict the dictionary in which the word/attributes are to be found. * @param formatOptions file format options. * @return false if none of the cached addresses inside the node changed, true otherwise. */ private static boolean computeActualNodeSize(final Node node, final FusionDictionary dict, final FormatOptions formatOptions) { boolean changed = false; int size = getGroupCountSize(node); for (CharGroup group : node.mData) { if (group.mCachedAddress != node.mCachedAddress + size) { changed = true; group.mCachedAddress = node.mCachedAddress + size; } int groupSize = getGroupHeaderSize(group, formatOptions); if (group.isTerminal()) groupSize += FormatSpec.GROUP_FREQUENCY_SIZE; if (null == group.mChildren && formatOptions.mSupportsDynamicUpdate) { groupSize += FormatSpec.SIGNED_CHILDREN_ADDRESS_SIZE; } else if (null != group.mChildren) { final int offsetBasePoint = groupSize + node.mCachedAddress + size; final int offset = group.mChildren.mCachedAddress - offsetBasePoint; if (formatOptions.mSupportsDynamicUpdate) { groupSize += FormatSpec.SIGNED_CHILDREN_ADDRESS_SIZE; } else { groupSize += getByteSize(offset); } } groupSize += getShortcutListSize(group.mShortcutTargets); if (null != group.mBigrams) { for (WeightedString bigram : group.mBigrams) { final int offsetBasePoint = groupSize + node.mCachedAddress + size + FormatSpec.GROUP_FLAGS_SIZE; final int addressOfBigram = findAddressOfWord(dict, bigram.mWord); final int offset = addressOfBigram - offsetBasePoint; groupSize += getByteSize(offset) + FormatSpec.GROUP_FLAGS_SIZE; } } group.mCachedSize = groupSize; size += groupSize; } if (formatOptions.mSupportsDynamicUpdate) { size += FormatSpec.FORWARD_LINK_ADDRESS_SIZE; } if (node.mCachedSize != size) { node.mCachedSize = size; changed = true; } return changed; } /** * Computes the byte size of a list of nodes and updates each node cached position. * * @param flatNodes the array of nodes. * @param formatOptions file format options. * @return the byte size of the entire stack. */ private static int stackNodes(final ArrayList flatNodes, final FormatOptions formatOptions) { int nodeOffset = 0; for (Node n : flatNodes) { n.mCachedAddress = nodeOffset; int groupCountSize = getGroupCountSize(n); int groupOffset = 0; for (CharGroup g : n.mData) { g.mCachedAddress = groupCountSize + nodeOffset + groupOffset; groupOffset += g.mCachedSize; } final int nodeSize = groupCountSize + groupOffset + (formatOptions.mSupportsDynamicUpdate ? FormatSpec.FORWARD_LINK_ADDRESS_SIZE : 0); if (nodeSize != n.mCachedSize) { throw new RuntimeException("Bug : Stored and computed node size differ"); } nodeOffset += n.mCachedSize; } return nodeOffset; } /** * Compute the cached parent addresses after all has been updated. * * The parent addresses are used by some binary formats at write-to-disk time. Not all formats * need them. In particular, version 2 does not need them, and version 3 does. * * @param flatNodes the flat array of nodes to fill in */ private static void computeParentAddresses(final ArrayList flatNodes) { for (final Node node : flatNodes) { for (CharGroup group : node.mData) { if (null != group.mChildren) { // assign my address to children's parent address group.mChildren.mCachedParentAddress = group.mCachedAddress - group.mChildren.mCachedAddress; } } } } /** * Compute the addresses and sizes of an ordered node array. * * This method takes a node array and will update its cached address and size values * so that they can be written into a file. It determines the smallest size each of the * nodes can be given the addresses of its children and attributes, and store that into * each node. * The order of the node is given by the order of the array. This method makes no effort * to find a good order; it only mechanically computes the size this order results in. * * @param dict the dictionary * @param flatNodes the ordered array of nodes * @param formatOptions file format options. * @return the same array it was passed. The nodes have been updated for address and size. */ private static ArrayList computeAddresses(final FusionDictionary dict, final ArrayList flatNodes, final FormatOptions formatOptions) { // First get the worst sizes and offsets for (Node n : flatNodes) setNodeMaximumSize(n, formatOptions); final int offset = stackNodes(flatNodes, formatOptions); MakedictLog.i("Compressing the array addresses. Original size : " + offset); MakedictLog.i("(Recursively seen size : " + offset + ")"); int passes = 0; boolean changesDone = false; do { changesDone = false; for (Node n : flatNodes) { final int oldNodeSize = n.mCachedSize; final boolean changed = computeActualNodeSize(n, dict, formatOptions); final int newNodeSize = n.mCachedSize; if (oldNodeSize < newNodeSize) throw new RuntimeException("Increased size ?!"); changesDone |= changed; } stackNodes(flatNodes, formatOptions); ++passes; if (passes > MAX_PASSES) throw new RuntimeException("Too many passes - probably a bug"); } while (changesDone); if (formatOptions.mSupportsDynamicUpdate) { computeParentAddresses(flatNodes); } final Node lastNode = flatNodes.get(flatNodes.size() - 1); MakedictLog.i("Compression complete in " + passes + " passes."); MakedictLog.i("After address compression : " + (lastNode.mCachedAddress + lastNode.mCachedSize)); return flatNodes; } /** * Sanity-checking method. * * This method checks an array of node for juxtaposition, that is, it will do * nothing if each node's cached address is actually the previous node's address * plus the previous node's size. * If this is not the case, it will throw an exception. * * @param array the array node to check */ private static void checkFlatNodeArray(final ArrayList array) { int offset = 0; int index = 0; for (Node n : array) { if (n.mCachedAddress != offset) { throw new RuntimeException("Wrong address for node " + index + " : expected " + offset + ", got " + n.mCachedAddress); } ++index; offset += n.mCachedSize; } } /** * Helper method to write a variable-size address to a file. * * @param buffer the buffer to write to. * @param index the index in the buffer to write the address to. * @param address the address to write. * @return the size in bytes the address actually took. */ private static int writeVariableAddress(final byte[] buffer, int index, final int address) { switch (getByteSize(address)) { case 1: buffer[index++] = (byte)address; return 1; case 2: buffer[index++] = (byte)(0xFF & (address >> 8)); buffer[index++] = (byte)(0xFF & address); return 2; case 3: buffer[index++] = (byte)(0xFF & (address >> 16)); buffer[index++] = (byte)(0xFF & (address >> 8)); buffer[index++] = (byte)(0xFF & address); return 3; case 0: return 0; default: throw new RuntimeException("Address " + address + " has a strange size"); } } /** * Helper method to write a variable-size signed address to a file. * * @param buffer the buffer to write to. * @param index the index in the buffer to write the address to. * @param address the address to write. * @return the size in bytes the address actually took. */ private static int writeVariableSignedAddress(final byte[] buffer, int index, final int address) { if (!hasChildrenAddress(address)) { buffer[index] = buffer[index + 1] = buffer[index + 2] = 0; } else { final int absAddress = Math.abs(address); buffer[index++] = (byte)((address < 0 ? MSB8 : 0) | (0xFF & (absAddress >> 16))); buffer[index++] = (byte)(0xFF & (absAddress >> 8)); buffer[index++] = (byte)(0xFF & absAddress); } return 3; } /** * Makes the flag value for a char group. * * @param hasMultipleChars whether the group has multiple chars. * @param isTerminal whether the group is terminal. * @param childrenAddressSize the size of a children address. * @param hasShortcuts whether the group has shortcuts. * @param hasBigrams whether the group has bigrams. * @param isNotAWord whether the group is not a word. * @param isBlackListEntry whether the group is a blacklist entry. * @param formatOptions file format options. * @return the flags */ static int makeCharGroupFlags(final boolean hasMultipleChars, final boolean isTerminal, final int childrenAddressSize, final boolean hasShortcuts, final boolean hasBigrams, final boolean isNotAWord, final boolean isBlackListEntry, final FormatOptions formatOptions) { byte flags = 0; if (hasMultipleChars) flags |= FormatSpec.FLAG_HAS_MULTIPLE_CHARS; if (isTerminal) flags |= FormatSpec.FLAG_IS_TERMINAL; if (formatOptions.mSupportsDynamicUpdate) { flags |= FormatSpec.FLAG_IS_NOT_MOVED; } else if (true) { switch (childrenAddressSize) { case 1: flags |= FormatSpec.FLAG_GROUP_ADDRESS_TYPE_ONEBYTE; break; case 2: flags |= FormatSpec.FLAG_GROUP_ADDRESS_TYPE_TWOBYTES; break; case 3: flags |= FormatSpec.FLAG_GROUP_ADDRESS_TYPE_THREEBYTES; break; case 0: flags |= FormatSpec.FLAG_GROUP_ADDRESS_TYPE_NOADDRESS; break; default: throw new RuntimeException("Node with a strange address"); } } if (hasShortcuts) flags |= FormatSpec.FLAG_HAS_SHORTCUT_TARGETS; if (hasBigrams) flags |= FormatSpec.FLAG_HAS_BIGRAMS; if (isNotAWord) flags |= FormatSpec.FLAG_IS_NOT_A_WORD; if (isBlackListEntry) flags |= FormatSpec.FLAG_IS_BLACKLISTED; return flags; } private static byte makeCharGroupFlags(final CharGroup group, final int groupAddress, final int childrenOffset, final FormatOptions formatOptions) { return (byte) makeCharGroupFlags(group.mChars.length > 1, group.mFrequency >= 0, getByteSize(childrenOffset), group.mShortcutTargets != null, group.mBigrams != null, group.mIsNotAWord, group.mIsBlacklistEntry, formatOptions); } /** * Makes the flag value for a bigram. * * @param more whether there are more bigrams after this one. * @param offset the offset of the bigram. * @param bigramFrequency the frequency of the bigram, 0..255. * @param unigramFrequency the unigram frequency of the same word, 0..255. * @param word the second bigram, for debugging purposes * @return the flags */ private static final int makeBigramFlags(final boolean more, final int offset, int bigramFrequency, final int unigramFrequency, final String word) { int bigramFlags = (more ? FormatSpec.FLAG_ATTRIBUTE_HAS_NEXT : 0) + (offset < 0 ? FormatSpec.FLAG_ATTRIBUTE_OFFSET_NEGATIVE : 0); switch (getByteSize(offset)) { case 1: bigramFlags |= FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_ONEBYTE; break; case 2: bigramFlags |= FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_TWOBYTES; break; case 3: bigramFlags |= FormatSpec.FLAG_ATTRIBUTE_ADDRESS_TYPE_THREEBYTES; break; default: throw new RuntimeException("Strange offset size"); } if (unigramFrequency > bigramFrequency) { MakedictLog.e("Unigram freq is superior to bigram freq for \"" + word + "\". Bigram freq is " + bigramFrequency + ", unigram freq for " + word + " is " + unigramFrequency); bigramFrequency = unigramFrequency; } // We compute the difference between 255 (which means probability = 1) and the // unigram score. We split this into a number of discrete steps. // Now, the steps are numbered 0~15; 0 represents an increase of 1 step while 15 // represents an increase of 16 steps: a value of 15 will be interpreted as the median // value of the 16th step. In all justice, if the bigram frequency is low enough to be // rounded below the first step (which means it is less than half a step higher than the // unigram frequency) then the unigram frequency itself is the best approximation of the // bigram freq that we could possibly supply, hence we should *not* include this bigram // in the file at all. // until this is done, we'll write 0 and slightly overestimate this case. // In other words, 0 means "between 0.5 step and 1.5 step", 1 means "between 1.5 step // and 2.5 steps", and 15 means "between 15.5 steps and 16.5 steps". So we want to // divide our range [unigramFreq..MAX_TERMINAL_FREQUENCY] in 16.5 steps to get the // step size. Then we compute the start of the first step (the one where value 0 starts) // by adding half-a-step to the unigramFrequency. From there, we compute the integer // number of steps to the bigramFrequency. One last thing: we want our steps to include // their lower bound and exclude their higher bound so we need to have the first step // start at exactly 1 unit higher than floor(unigramFreq + half a step). // Note : to reconstruct the score, the dictionary reader will need to divide // MAX_TERMINAL_FREQUENCY - unigramFreq by 16.5 likewise to get the value of the step, // and add (discretizedFrequency + 0.5 + 0.5) times this value to get the best // approximation. (0.5 to get the first step start, and 0.5 to get the middle of the // step pointed by the discretized frequency. final float stepSize = (FormatSpec.MAX_TERMINAL_FREQUENCY - unigramFrequency) / (1.5f + FormatSpec.MAX_BIGRAM_FREQUENCY); final float firstStepStart = 1 + unigramFrequency + (stepSize / 2.0f); final int discretizedFrequency = (int)((bigramFrequency - firstStepStart) / stepSize); // If the bigram freq is less than half-a-step higher than the unigram freq, we get -1 // here. The best approximation would be the unigram freq itself, so we should not // include this bigram in the dictionary. For now, register as 0, and live with the // small over-estimation that we get in this case. TODO: actually remove this bigram // if discretizedFrequency < 0. final int finalBigramFrequency = discretizedFrequency > 0 ? discretizedFrequency : 0; bigramFlags += finalBigramFrequency & FormatSpec.FLAG_ATTRIBUTE_FREQUENCY; return bigramFlags; } /** * Makes the 2-byte value for options flags. */ private static final int makeOptionsValue(final FusionDictionary dictionary, final FormatOptions formatOptions) { final DictionaryOptions options = dictionary.mOptions; final boolean hasBigrams = dictionary.hasBigrams(); return (options.mFrenchLigatureProcessing ? FormatSpec.FRENCH_LIGATURE_PROCESSING_FLAG : 0) + (options.mGermanUmlautProcessing ? FormatSpec.GERMAN_UMLAUT_PROCESSING_FLAG : 0) + (hasBigrams ? FormatSpec.CONTAINS_BIGRAMS_FLAG : 0) + (formatOptions.mSupportsDynamicUpdate ? FormatSpec.SUPPORTS_DYNAMIC_UPDATE : 0); } /** * Makes the flag value for a shortcut. * * @param more whether there are more attributes after this one. * @param frequency the frequency of the attribute, 0..15 * @return the flags */ static final int makeShortcutFlags(final boolean more, final int frequency) { return (more ? FormatSpec.FLAG_ATTRIBUTE_HAS_NEXT : 0) + (frequency & FormatSpec.FLAG_ATTRIBUTE_FREQUENCY); } private static final int writeParentAddress(final byte[] buffer, final int index, final int address, final FormatOptions formatOptions) { if (supportsDynamicUpdate(formatOptions)) { if (address == FormatSpec.NO_PARENT_ADDRESS) { buffer[index] = buffer[index + 1] = buffer[index + 2] = 0; } else { final int absAddress = Math.abs(address); assert(absAddress <= SINT24_MAX); buffer[index] = (byte)((address < 0 ? MSB8 : 0) | ((absAddress >> 16) & 0xFF)); buffer[index + 1] = (byte)((absAddress >> 8) & 0xFF); buffer[index + 2] = (byte)(absAddress & 0xFF); } return index + 3; } else { return index; } } /** * Write a node to memory. The node is expected to have its final position cached. * * This can be an empty map, but the more is inside the faster the lookups will be. It can * be carried on as long as nodes do not move. * * @param dict the dictionary the node is a part of (for relative offsets). * @param buffer the memory buffer to write to. * @param node the node to write. * @param formatOptions file format options. * @return the address of the END of the node. */ @SuppressWarnings("unused") private static int writePlacedNode(final FusionDictionary dict, byte[] buffer, final Node node, final FormatOptions formatOptions) { // TODO: Make the code in common with BinaryDictIOUtils#writeCharGroup int index = node.mCachedAddress; final int groupCount = node.mData.size(); final int countSize = getGroupCountSize(node); final int parentAddress = node.mCachedParentAddress; if (1 == countSize) { buffer[index++] = (byte)groupCount; } else if (2 == countSize) { // We need to signal 2-byte size by setting the top bit of the MSB to 1, so // we | 0x80 to do this. buffer[index++] = (byte)((groupCount >> 8) | 0x80); buffer[index++] = (byte)(groupCount & 0xFF); } else { throw new RuntimeException("Strange size from getGroupCountSize : " + countSize); } int groupAddress = index; for (int i = 0; i < groupCount; ++i) { CharGroup group = node.mData.get(i); if (index != group.mCachedAddress) throw new RuntimeException("Bug: write index is not " + "the same as the cached address of the group : " + index + " <> " + group.mCachedAddress); groupAddress += getGroupHeaderSize(group, formatOptions); // Sanity checks. if (DBG && group.mFrequency > FormatSpec.MAX_TERMINAL_FREQUENCY) { throw new RuntimeException("A node has a frequency > " + FormatSpec.MAX_TERMINAL_FREQUENCY + " : " + group.mFrequency); } if (group.mFrequency >= 0) groupAddress += FormatSpec.GROUP_FREQUENCY_SIZE; final int childrenOffset = null == group.mChildren ? FormatSpec.NO_CHILDREN_ADDRESS : group.mChildren.mCachedAddress - groupAddress; byte flags = makeCharGroupFlags(group, groupAddress, childrenOffset, formatOptions); buffer[index++] = flags; if (parentAddress == FormatSpec.NO_PARENT_ADDRESS) { index = writeParentAddress(buffer, index, parentAddress, formatOptions); } else { index = writeParentAddress(buffer, index, parentAddress + (node.mCachedAddress - group.mCachedAddress), formatOptions); } index = CharEncoding.writeCharArray(group.mChars, buffer, index); if (group.hasSeveralChars()) { buffer[index++] = FormatSpec.GROUP_CHARACTERS_TERMINATOR; } if (group.mFrequency >= 0) { buffer[index++] = (byte) group.mFrequency; } final int shift; if (formatOptions.mSupportsDynamicUpdate) { shift = writeVariableSignedAddress(buffer, index, childrenOffset); } else { shift = writeVariableAddress(buffer, index, childrenOffset); } index += shift; groupAddress += shift; // Write shortcuts if (null != group.mShortcutTargets) { final int indexOfShortcutByteSize = index; index += FormatSpec.GROUP_SHORTCUT_LIST_SIZE_SIZE; groupAddress += FormatSpec.GROUP_SHORTCUT_LIST_SIZE_SIZE; final Iterator shortcutIterator = group.mShortcutTargets.iterator(); while (shortcutIterator.hasNext()) { final WeightedString target = shortcutIterator.next(); ++groupAddress; int shortcutFlags = makeShortcutFlags(shortcutIterator.hasNext(), target.mFrequency); buffer[index++] = (byte)shortcutFlags; final int shortcutShift = CharEncoding.writeString(buffer, index, target.mWord); index += shortcutShift; groupAddress += shortcutShift; } final int shortcutByteSize = index - indexOfShortcutByteSize; if (shortcutByteSize > 0xFFFF) { throw new RuntimeException("Shortcut list too large"); } buffer[indexOfShortcutByteSize] = (byte)(shortcutByteSize >> 8); buffer[indexOfShortcutByteSize + 1] = (byte)(shortcutByteSize & 0xFF); } // Write bigrams if (null != group.mBigrams) { final Iterator bigramIterator = group.mBigrams.iterator(); while (bigramIterator.hasNext()) { final WeightedString bigram = bigramIterator.next(); final CharGroup target = FusionDictionary.findWordInTree(dict.mRoot, bigram.mWord); final int addressOfBigram = target.mCachedAddress; final int unigramFrequencyForThisWord = target.mFrequency; ++groupAddress; final int offset = addressOfBigram - groupAddress; int bigramFlags = makeBigramFlags(bigramIterator.hasNext(), offset, bigram.mFrequency, unigramFrequencyForThisWord, bigram.mWord); buffer[index++] = (byte)bigramFlags; final int bigramShift = writeVariableAddress(buffer, index, Math.abs(offset)); index += bigramShift; groupAddress += bigramShift; } } } if (formatOptions.mSupportsDynamicUpdate) { buffer[index] = buffer[index + 1] = buffer[index + 2] = FormatSpec.NO_FORWARD_LINK_ADDRESS; index += FormatSpec.FORWARD_LINK_ADDRESS_SIZE; } if (index != node.mCachedAddress + node.mCachedSize) throw new RuntimeException( "Not the same size : written " + (index - node.mCachedAddress) + " bytes out of a node that should have " + node.mCachedSize + " bytes"); return index; } /** * Dumps a collection of useful statistics about a node array. * * This prints purely informative stuff, like the total estimated file size, the * number of nodes, of character groups, the repartition of each address size, etc * * @param nodes the node array. */ private static void showStatistics(ArrayList nodes) { int firstTerminalAddress = Integer.MAX_VALUE; int lastTerminalAddress = Integer.MIN_VALUE; int size = 0; int charGroups = 0; int maxGroups = 0; int maxRuns = 0; for (Node n : nodes) { if (maxGroups < n.mData.size()) maxGroups = n.mData.size(); for (CharGroup cg : n.mData) { ++charGroups; if (cg.mChars.length > maxRuns) maxRuns = cg.mChars.length; if (cg.mFrequency >= 0) { if (n.mCachedAddress < firstTerminalAddress) firstTerminalAddress = n.mCachedAddress; if (n.mCachedAddress > lastTerminalAddress) lastTerminalAddress = n.mCachedAddress; } } if (n.mCachedAddress + n.mCachedSize > size) size = n.mCachedAddress + n.mCachedSize; } final int[] groupCounts = new int[maxGroups + 1]; final int[] runCounts = new int[maxRuns + 1]; for (Node n : nodes) { ++groupCounts[n.mData.size()]; for (CharGroup cg : n.mData) { ++runCounts[cg.mChars.length]; } } MakedictLog.i("Statistics:\n" + " total file size " + size + "\n" + " " + nodes.size() + " nodes\n" + " " + charGroups + " groups (" + ((float)charGroups / nodes.size()) + " groups per node)\n" + " first terminal at " + firstTerminalAddress + "\n" + " last terminal at " + lastTerminalAddress + "\n" + " Group stats : max = " + maxGroups); for (int i = 0; i < groupCounts.length; ++i) { MakedictLog.i(" " + i + " : " + groupCounts[i]); } MakedictLog.i(" Character run stats : max = " + maxRuns); for (int i = 0; i < runCounts.length; ++i) { MakedictLog.i(" " + i + " : " + runCounts[i]); } } /** * Dumps a FusionDictionary to a file. * * This is the public entry point to write a dictionary to a file. * * @param destination the stream to write the binary data to. * @param dict the dictionary to write. * @param formatOptions file format options. */ public static void writeDictionaryBinary(final OutputStream destination, final FusionDictionary dict, final FormatOptions formatOptions) throws IOException, UnsupportedFormatException { // Addresses are limited to 3 bytes, but since addresses can be relative to each node, the // structure itself is not limited to 16MB. However, if it is over 16MB deciding the order // of the nodes becomes a quite complicated problem, because though the dictionary itself // does not have a size limit, each node must still be within 16MB of all its children and // parents. As long as this is ensured, the dictionary file may grow to any size. final int version = formatOptions.mVersion; if (version < FormatSpec.MINIMUM_SUPPORTED_VERSION || version > FormatSpec.MAXIMUM_SUPPORTED_VERSION) { throw new UnsupportedFormatException("Requested file format version " + version + ", but this implementation only supports versions " + FormatSpec.MINIMUM_SUPPORTED_VERSION + " through " + FormatSpec.MAXIMUM_SUPPORTED_VERSION); } ByteArrayOutputStream headerBuffer = new ByteArrayOutputStream(256); // The magic number in big-endian order. if (version >= FormatSpec.FIRST_VERSION_WITH_HEADER_SIZE) { // Magic number for version 2+. headerBuffer.write((byte) (0xFF & (FormatSpec.VERSION_2_MAGIC_NUMBER >> 24))); headerBuffer.write((byte) (0xFF & (FormatSpec.VERSION_2_MAGIC_NUMBER >> 16))); headerBuffer.write((byte) (0xFF & (FormatSpec.VERSION_2_MAGIC_NUMBER >> 8))); headerBuffer.write((byte) (0xFF & FormatSpec.VERSION_2_MAGIC_NUMBER)); // Dictionary version. headerBuffer.write((byte) (0xFF & (version >> 8))); headerBuffer.write((byte) (0xFF & version)); } else { // Magic number for version 1. headerBuffer.write((byte) (0xFF & (FormatSpec.VERSION_1_MAGIC_NUMBER >> 8))); headerBuffer.write((byte) (0xFF & FormatSpec.VERSION_1_MAGIC_NUMBER)); // Dictionary version. headerBuffer.write((byte) (0xFF & version)); } // Options flags final int options = makeOptionsValue(dict, formatOptions); headerBuffer.write((byte) (0xFF & (options >> 8))); headerBuffer.write((byte) (0xFF & options)); if (version >= FormatSpec.FIRST_VERSION_WITH_HEADER_SIZE) { final int headerSizeOffset = headerBuffer.size(); // Placeholder to be written later with header size. for (int i = 0; i < 4; ++i) { headerBuffer.write(0); } // Write out the options. for (final String key : dict.mOptions.mAttributes.keySet()) { final String value = dict.mOptions.mAttributes.get(key); CharEncoding.writeString(headerBuffer, key); CharEncoding.writeString(headerBuffer, value); } final int size = headerBuffer.size(); final byte[] bytes = headerBuffer.toByteArray(); // Write out the header size. bytes[headerSizeOffset] = (byte) (0xFF & (size >> 24)); bytes[headerSizeOffset + 1] = (byte) (0xFF & (size >> 16)); bytes[headerSizeOffset + 2] = (byte) (0xFF & (size >> 8)); bytes[headerSizeOffset + 3] = (byte) (0xFF & (size >> 0)); destination.write(bytes); } else { headerBuffer.writeTo(destination); } headerBuffer.close(); // Leave the choice of the optimal node order to the flattenTree function. MakedictLog.i("Flattening the tree..."); ArrayList flatNodes = flattenTree(dict.mRoot); MakedictLog.i("Computing addresses..."); computeAddresses(dict, flatNodes, formatOptions); MakedictLog.i("Checking array..."); if (DBG) checkFlatNodeArray(flatNodes); // Create a buffer that matches the final dictionary size. final Node lastNode = flatNodes.get(flatNodes.size() - 1); final int bufferSize = lastNode.mCachedAddress + lastNode.mCachedSize; final byte[] buffer = new byte[bufferSize]; int index = 0; MakedictLog.i("Writing file..."); int dataEndOffset = 0; for (Node n : flatNodes) { dataEndOffset = writePlacedNode(dict, buffer, n, formatOptions); } if (DBG) showStatistics(flatNodes); destination.write(buffer, 0, dataEndOffset); destination.close(); MakedictLog.i("Done"); } // Input methods: Read a binary dictionary to memory. // readDictionaryBinary is the public entry point for them. static int getChildrenAddressSize(final int optionFlags, final FormatOptions formatOptions) { if (formatOptions.mSupportsDynamicUpdate) return FormatSpec.SIGNED_CHILDREN_ADDRESS_SIZE; switch (optionFlags & FormatSpec.MASK_GROUP_ADDRESS_TYPE) { case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_ONEBYTE: return 1; case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_TWOBYTES: return 2; case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_THREEBYTES: return 3; case FormatSpec.FLAG_GROUP_ADDRESS_TYPE_NOADDRESS: default: return 0; } } 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 & MSB24) != 0) { return -(address & 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 (supportsDynamicUpdate(formatOptions)) { final int parentAddress = buffer.readUnsignedInt24(); final int sign = ((parentAddress & MSB24) != 0) ? -1 : 1; return sign * (parentAddress & 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 (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 += getChildrenAddressSize(flags, options); ArrayList shortcutTargets = null; if (0 != (flags & FormatSpec.FLAG_HAS_SHORTCUT_TARGETS)) { final int pointerBefore = buffer.position(); shortcutTargets = new ArrayList(); 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 bigrams = null; if (0 != (flags & FormatSpec.FLAG_HAS_BIGRAMS)) { bigrams = new ArrayList(); 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"); } 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."); } } 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(); } } // The word cache here is a stopgap bandaid to help the catastrophic performance // of this method. Since it performs direct, unbuffered random access to the file and // may be called hundreds of thousands of times, the resulting performance is not // reasonable without some kind of cache. Thus: private static TreeMap wordCache = new TreeMap(); /** * Finds, as a string, the word at the address passed as an argument. * * @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. */ /* package for tests */ static WeightedString getWordAtAddress( final FusionDictionaryBufferInterface buffer, final int headerSize, final int address, final FormatOptions formatOptions) { final WeightedString cachedString = wordCache.get(address); if (null != cachedString) return cachedString; final WeightedString result; final int originalPointer = buffer.position(); buffer.position(address); if (supportsDynamicUpdate(formatOptions)) { result = getWordAtAddressWithParentAddress(buffer, headerSize, address, formatOptions); } else { result = getWordAtAddressWithoutParentAddress(buffer, headerSize, address, formatOptions); } wordCache.put(address, result); buffer.position(originalPointer); return result; } // TODO: static!? This will behave erratically when used in multi-threaded code. // We need to fix this private static int[] sGetWordBuffer = new int[FormatSpec.MAX_WORD_LENGTH]; @SuppressWarnings("unused") private static WeightedString getWordAtAddressWithParentAddress( final FusionDictionaryBufferInterface buffer, final int headerSize, final int address, final FormatOptions options) { int currentAddress = address; int index = FormatSpec.MAX_WORD_LENGTH - 1; int frequency = Integer.MIN_VALUE; // 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 (isMovedGroup(currentInfo.mFlags, options)) { currentAddress = currentInfo.mParentAddress + currentInfo.mOriginalAddress; } if (DBG && loopCounter++ > MAX_JUMPS) { MakedictLog.d("Too many jumps - probably a bug"); } } while (isMovedGroup(currentInfo.mFlags, options)); if (Integer.MIN_VALUE == frequency) frequency = currentInfo.mFrequency; for (int i = 0; i < currentInfo.mCharacters.length; ++i) { sGetWordBuffer[index--] = currentInfo.mCharacters[currentInfo.mCharacters.length - i - 1]; } if (currentInfo.mParentAddress == FormatSpec.NO_PARENT_ADDRESS) break; currentAddress = currentInfo.mParentAddress + currentInfo.mOriginalAddress; } return new WeightedString( new String(sGetWordBuffer, index + 1, FormatSpec.MAX_WORD_LENGTH - index - 1), 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 = 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 (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 + getGroupCountSize(i); last = null; continue; } last = info; } if (0 == i && hasChildrenAddress(last.mChildrenAddress)) { builder.append(new String(last.mCharacters, 0, last.mCharacters.length)); buffer.position(last.mChildrenAddress + headerSize); i = readCharGroupCount(buffer); groupOffset = last.mChildrenAddress + getGroupCountSize(i); last = null; continue; } } return result; } /** * Reads a single node from a buffer. * * This methods reads the file at the current position. A node is fully expected to start at * the current position. * This will recursively read other nodes 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. * @param headerSize the size, in bytes, of the file header. * @param reverseNodeMap a mapping from addresses to already read nodes. * @param reverseGroupMap a mapping from addresses to already read character groups. * @param options file format options. * @return the read node with all his children already read. */ private static Node readNode(final FusionDictionaryBufferInterface buffer, final int headerSize, final Map reverseNodeMap, final Map reverseGroupMap, final FormatOptions options) throws IOException { final ArrayList nodeContents = new ArrayList(); final int nodeOrigin = buffer.position() - headerSize; do { // Scan the linked-list node. final int nodeHeadPosition = buffer.position() - headerSize; final int count = readCharGroupCount(buffer); int groupOffset = nodeHeadPosition + getGroupCountSize(count); for (int i = count; i > 0; --i) { // Scan the array of CharGroup. CharGroupInfo info = readCharGroup(buffer, groupOffset, options); if (isMovedGroup(info.mFlags, options)) continue; ArrayList shortcutTargets = info.mShortcutTargets; ArrayList bigrams = null; if (null != info.mBigrams) { bigrams = new ArrayList(); 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 (hasChildrenAddress(info.mChildrenAddress)) { Node children = reverseNodeMap.get(info.mChildrenAddress); if (null == children) { final int currentPosition = buffer.position(); buffer.position(info.mChildrenAddress + headerSize); children = readNode( buffer, headerSize, reverseNodeMap, reverseGroupMap, options); buffer.position(currentPosition); } nodeContents.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 { nodeContents.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))); } 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; } } } while (options.mSupportsDynamicUpdate && buffer.position() != FormatSpec.NO_FORWARD_LINK_ADDRESS); final Node node = new Node(nodeContents); node.mCachedAddress = nodeOrigin; reverseNodeMap.put(node.mCachedAddress, node); return node; } /** * 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_v1 = buffer.readUnsignedShort(); if (FormatSpec.VERSION_1_MAGIC_NUMBER == magic_v1) return buffer.readUnsignedByte(); final int magic_v2 = (magic_v1 << 16) + buffer.readUnsignedShort(); if (FormatSpec.VERSION_2_MAGIC_NUMBER == magic_v2) return buffer.readUnsignedShort(); return FormatSpec.NOT_A_VERSION_NUMBER; } /** * Helper function to get and validate the binary format version. * @throws UnsupportedFormatException * @throws IOException */ private 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 version; } /** * Reads a header from a buffer. * @param buffer the buffer to read. * @throws IOException * @throws UnsupportedFormatException */ public static FileHeader readHeader(final FusionDictionaryBufferInterface buffer) throws IOException, UnsupportedFormatException { final int version = checkFormatVersion(buffer); final int optionsFlags = buffer.readUnsignedShort(); final HashMap attributes = new HashMap(); final int headerSize; if (version < FormatSpec.FIRST_VERSION_WITH_HEADER_SIZE) { headerSize = buffer.position(); } else { headerSize = buffer.readInt(); populateOptions(buffer, headerSize, attributes); buffer.position(headerSize); } if (headerSize < 0) { throw new UnsupportedFormatException("header size can't be negative."); } 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; } /** * 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 options) { while (buffer.position() < headerSize) { final String key = CharEncoding.readString(buffer); final String value = CharEncoding.readString(buffer); options.put(key, value); } } /** * 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 buffer the buffer to read. * @param dict an optional dictionary to add words to, or null. * @return the created (or merged) dictionary. */ @UsedForTesting public static FusionDictionary readDictionaryBinary( final FusionDictionaryBufferInterface buffer, final FusionDictionary dict) throws IOException, UnsupportedFormatException { // clear cache wordCache.clear(); // Read header final FileHeader header = readHeader(buffer); Map reverseNodeMapping = new TreeMap(); Map reverseGroupMapping = new TreeMap(); final Node root = readNode(buffer, header.mHeaderSize, reverseNodeMapping, reverseGroupMapping, header.mFormatOptions); FusionDictionary newDict = new FusionDictionary(root, header.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); } } } return newDict; } /** * 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); } /** * 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 } } } } /** * Calculate bigram frequency from compressed value * * @see #makeBigramFlags * * @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; } }