Change the format of the shortcuts in the binary dict.

This only includes the write part of the change. The read part is
coming in a different commit.

Change-Id: Iabe7af6cd134462dc19245f5400719920ed31c8f
main
Jean Chalard 2012-03-27 12:36:19 +09:00
parent 1ebebebc44
commit 3bbb31f3f0
1 changed files with 107 additions and 44 deletions

View File

@ -47,7 +47,6 @@ public class BinaryDictInputOutput {
* s | has a terminal ? 1 bit, 1 = yes, 0 = no : FLAG_IS_TERMINAL
* | has shortcut targets ? 1 bit, 1 = yes, 0 = no : FLAG_HAS_SHORTCUT_TARGETS
* | has bigrams ? 1 bit, 1 = yes, 0 = no : FLAG_HAS_BIGRAMS
* | is shortcut only ? 1 bit, 1 = yes, 0 = no : FLAG_IS_SHORTCUT_ONLY
*
* c | IF FLAG_HAS_MULTIPLE_CHARS
* h | char, char, char, char n * (1 or 3 bytes) : use CharGroupInfo for i/o helpers
@ -74,7 +73,7 @@ public class BinaryDictInputOutput {
* dress
*
* | IF FLAG_IS_TERMINAL && FLAG_HAS_SHORTCUT_TARGETS
* | shortcut targets address list
* | shortcut string list
* | IF FLAG_IS_TERMINAL && FLAG_HAS_BIGRAMS
* | bigrams address list
*
@ -89,7 +88,7 @@ public class BinaryDictInputOutput {
* 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).
*
* bigram and shortcut address list is:
* bigram address list is:
* <flags> = | hasNext = 1 bit, 1 = yes, 0 = no : FLAG_ATTRIBUTE_HAS_NEXT
* | addressSign = 1 bit, : FLAG_ATTRIBUTE_OFFSET_NEGATIVE
* | 1 = must take -address, 0 = must take +address
@ -107,8 +106,16 @@ public class BinaryDictInputOutput {
* | read 3 bytes, add top 4 bits
* | END
* | if (FLAG_ATTRIBUTE_OFFSET_NEGATIVE) then address = -address
* if (FLAG_ATTRIBUTE_HAS_NET) goto bigram_and_shortcut_address_list_is
* if (FLAG_ATTRIBUTE_HAS_NEXT) goto bigram_and_shortcut_address_list_is
*
* shortcut string list is:
* <byte size> = GROUP_SHORTCUT_LIST_SIZE_SIZE bytes, big-endian: size of the list, in bytes.
* <flags> = | hasNext = 1 bit, 1 = yes, 0 = no : FLAG_ATTRIBUTE_HAS_NEXT
* | reserved = 3 bits, must be 0
* | 4 bits : frequency : mask with FLAG_ATTRIBUTE_FREQUENCY
* <shortcut> = | string of characters at the char format described above, with the terminator
* | used to signal the end of the string.
* if (FLAG_ATTRIBUTE_HAS_NEXT goto flags
*/
private static final int VERSION_1_MAGIC_NUMBER = 0x78B1;
@ -136,7 +143,6 @@ public class BinaryDictInputOutput {
private static final int FLAG_IS_TERMINAL = 0x10;
private static final int FLAG_HAS_SHORTCUT_TARGETS = 0x08;
private static final int FLAG_HAS_BIGRAMS = 0x04;
private static final int FLAG_IS_SHORTCUT_ONLY = 0x02;
private static final int FLAG_ATTRIBUTE_HAS_NEXT = 0x80;
private static final int FLAG_ATTRIBUTE_OFFSET_NEGATIVE = 0x40;
@ -154,6 +160,7 @@ public class BinaryDictInputOutput {
private static final int GROUP_MAX_ADDRESS_SIZE = 3;
private static final int GROUP_ATTRIBUTE_FLAGS_SIZE = 1;
private static final int GROUP_ATTRIBUTE_MAX_ADDRESS_SIZE = 3;
private static final int GROUP_SHORTCUT_LIST_SIZE_SIZE = 2;
private static final int NO_CHILDREN_ADDRESS = Integer.MIN_VALUE;
private static final int INVALID_CHARACTER = -1;
@ -215,24 +222,52 @@ public class BinaryDictInputOutput {
/**
* Writes a char array to a byte buffer.
*
* @param characters the character array to write.
* @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(int[] characters, byte[] buffer, int index) {
for (int character : characters) {
if (1 == getCharSize(character)) {
buffer[index++] = (byte)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 & (character >> 16));
buffer[index++] = (byte)(0xFF & (character >> 8));
buffer[index++] = (byte)(0xFF & character);
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++] = GROUP_CHARACTERS_TERMINATOR;
return index - origin;
}
/**
* Reads a character from the file.
*
@ -293,6 +328,36 @@ public class BinaryDictInputOutput {
return getGroupCountSize(node.mData.size());
}
/**
* Compute the size of a shortcut in bytes.
*/
private static int getShortcutSize(final WeightedString shortcut) {
int size = 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 += 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.
*/
private static int getShortcutListSize(final ArrayList<WeightedString> shortcutList) {
if (null == shortcutList) return 0;
int size = 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.
*
@ -304,10 +369,7 @@ public class BinaryDictInputOutput {
// If terminal, one byte for the frequency
if (group.isTerminal()) size += GROUP_FREQUENCY_SIZE;
size += GROUP_MAX_ADDRESS_SIZE; // For children address
if (null != group.mShortcutTargets) {
size += (GROUP_ATTRIBUTE_FLAGS_SIZE + GROUP_ATTRIBUTE_MAX_ADDRESS_SIZE)
* group.mShortcutTargets.size();
}
size += getShortcutListSize(group.mShortcutTargets);
if (null != group.mBigrams) {
size += (GROUP_ATTRIBUTE_FLAGS_SIZE + GROUP_ATTRIBUTE_MAX_ADDRESS_SIZE)
* group.mBigrams.size();
@ -338,13 +400,6 @@ public class BinaryDictInputOutput {
return NO_CHILDREN_ADDRESS != address;
}
/**
* Helper method to find out if a character info is a shortcut only.
*/
private static boolean isShortcutOnly(final CharGroupInfo info) {
return 0 != (info.mFlags & FLAG_IS_SHORTCUT_ONLY);
}
/**
* Compute the size, in bytes, that an address will occupy.
*
@ -430,15 +485,7 @@ public class BinaryDictInputOutput {
final int offset = group.mChildren.mCachedAddress - offsetBasePoint;
groupSize += getByteSize(offset);
}
if (null != group.mShortcutTargets) {
for (WeightedString target : group.mShortcutTargets) {
final int offsetBasePoint = groupSize + node.mCachedAddress + size
+ GROUP_FLAGS_SIZE;
final int addressOfTarget = findAddressOfWord(dict, target.mWord);
final int offset = addressOfTarget - offsetBasePoint;
groupSize += getByteSize(offset) + GROUP_FLAGS_SIZE;
}
}
groupSize += getShortcutListSize(group.mShortcutTargets);
if (null != group.mBigrams) {
for (WeightedString bigram : group.mBigrams) {
final int offsetBasePoint = groupSize + node.mCachedAddress + size
@ -555,7 +602,7 @@ public class BinaryDictInputOutput {
* @param address the address to write.
* @return the size in bytes the address actually took.
*/
private static int writeVariableAddress(byte[] buffer, int index, int address) {
private static int writeVariableAddress(final byte[] buffer, int index, final int address) {
switch (getByteSize(address)) {
case 1:
buffer[index++] = (byte)address;
@ -610,9 +657,6 @@ public class BinaryDictInputOutput {
}
flags |= FLAG_HAS_BIGRAMS;
}
if (group.mIsShortcutOnly) {
flags |= FLAG_IS_SHORTCUT_ONLY;
}
return flags;
}
@ -645,6 +689,17 @@ public class BinaryDictInputOutput {
return bigramFlags;
}
/**
* 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
*/
private static final int makeShortcutFlags(final boolean more, final int frequency) {
return (more ? FLAG_ATTRIBUTE_HAS_NEXT : 0) + (frequency & FLAG_ATTRIBUTE_FREQUENCY);
}
/**
* Write a node to memory. The node is expected to have its final position cached.
*
@ -675,7 +730,8 @@ public class BinaryDictInputOutput {
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");
+ "the same as the cached address of the group : "
+ index + " <> " + group.mCachedAddress);
groupAddress += GROUP_FLAGS_SIZE + getGroupCharactersSize(group);
// Sanity checks.
if (group.mFrequency > MAX_TERMINAL_FREQUENCY) {
@ -700,19 +756,26 @@ public class BinaryDictInputOutput {
// Write shortcuts
if (null != group.mShortcutTargets) {
final int indexOfShortcutByteSize = index;
index += GROUP_SHORTCUT_LIST_SIZE_SIZE;
groupAddress += GROUP_SHORTCUT_LIST_SIZE_SIZE;
final Iterator shortcutIterator = group.mShortcutTargets.iterator();
while (shortcutIterator.hasNext()) {
final WeightedString target = (WeightedString)shortcutIterator.next();
final int addressOfTarget = findAddressOfWord(dict, target.mWord);
++groupAddress;
final int offset = addressOfTarget - groupAddress;
int shortcutFlags = makeAttributeFlags(shortcutIterator.hasNext(), offset,
int shortcutFlags = makeShortcutFlags(shortcutIterator.hasNext(),
target.mFrequency);
buffer[index++] = (byte)shortcutFlags;
final int shortcutShift = writeVariableAddress(buffer, index, Math.abs(offset));
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) {
@ -1112,11 +1175,11 @@ public class BinaryDictInputOutput {
}
nodeContents.add(
new CharGroup(info.mCharacters, shortcutTargets, bigrams, info.mFrequency,
children, isShortcutOnly(info)));
children, false));
} else {
nodeContents.add(
new CharGroup(info.mCharacters, shortcutTargets, bigrams, info.mFrequency,
isShortcutOnly(info)));
false));
}
groupOffset = info.mEndAddress;
}