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ara-mdk / platform / packages / inputmethods / LatinIME / 5fb6a99bd6a41f26d27a77400ab41087b9248fce / . / java / src / com / android / inputmethod / latin / makedict / BinaryDictInputOutput.java
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/*
* 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<WeightedString> 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<Node> flattenTree(final Node root) {
final int treeSize = FusionDictionary.countCharGroups(root);
MakedictLog.i("Counted nodes : " + treeSize);
final ArrayList<Node> flatTree = new ArrayList<Node>(treeSize);
return flattenTreeInner(flatTree, root);
}
private static ArrayList<Node> flattenTreeInner(final ArrayList<Node> 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<CharGroup> 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;
// assign my address to children's parent address
group.mChildren.mCachedParentAddress = group.mCachedAddress
- group.mChildren.mCachedAddress;
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<Node> 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 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<Node> computeAddresses(final FusionDictionary dict,
final ArrayList<Node> 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);
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<Node> 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<WeightedString> 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<WeightedString> 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<Node> 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<Node> 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<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");
}
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<Integer, WeightedString> wordCache =
new TreeMap<Integer, WeightedString>();
/**
* 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<Integer, Node> reverseNodeMap, final Map<Integer, CharGroup> reverseGroupMap,
final FormatOptions options)
throws IOException {
final ArrayList<CharGroup> nodeContents = new ArrayList<CharGroup>();
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<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 (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<String, String> attributes = new HashMap<String, String>();
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<String, String> 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<Integer, Node> reverseNodeMapping = new TreeMap<Integer, Node>();
Map<Integer, CharGroup> reverseGroupMapping = new TreeMap<Integer, CharGroup>();
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;
}
}