com.ibm.icu.util.CompactByteArray Maven / Gradle / Ivy
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html#License
/*
*******************************************************************************
* Copyright (C) 1996-2014, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*/
package com.ibm.icu.util;
import com.ibm.icu.impl.Utility;
/**
* class CompactATypeArray : use only on primitive data types
* Provides a compact way to store information that is indexed by Unicode
* values, such as character properties, types, keyboard values, etc.This
* is very useful when you have a block of Unicode data that contains
* significant values while the rest of the Unicode data is unused in the
* application or when you have a lot of redundance, such as where all 21,000
* Han ideographs have the same value. However, lookup is much faster than a
* hash table.
* A compact array of any primitive data type serves two purposes:
*
* - Fast access of the indexed values.
*
- Smaller memory footprint.
*
* A compact array is composed of a index array and value array. The index
* array contains the indicies of Unicode characters to the value array.
*
* @see CompactCharArray
* @author Helena Shih
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public final class CompactByteArray implements Cloneable {
/**
* The total number of Unicode characters.
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public static final int UNICODECOUNT =65536;
/**
* Default constructor for CompactByteArray, the default value of the
* compact array is 0.
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public CompactByteArray()
{
this((byte)0);
}
/**
* Constructor for CompactByteArray.
* @param defaultValue the default value of the compact array.
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public CompactByteArray(byte defaultValue)
{
int i;
values = new byte[UNICODECOUNT];
indices = new char[INDEXCOUNT];
hashes = new int[INDEXCOUNT];
for (i = 0; i < UNICODECOUNT; ++i) {
values[i] = defaultValue;
}
for (i = 0; i < INDEXCOUNT; ++i) {
indices[i] = (char)(i<= newValues.length+BLOCKCOUNT)
throw new IllegalArgumentException("Index out of bounds.");
}
indices = indexArray;
values = newValues;
isCompact = true;
}
/**
* Constructor for CompactByteArray.
*
* @param indexArray the RLE-encoded indicies of the compact array.
* @param valueArray the RLE-encoded values of the compact array.
*
* @throws IllegalArgumentException if the index or value array is
* the wrong size.
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public CompactByteArray(String indexArray,
String valueArray)
{
this( Utility.RLEStringToCharArray(indexArray),
Utility.RLEStringToByteArray(valueArray));
}
/**
* Get the mapped value of a Unicode character.
* @param index the character to get the mapped value with
* @return the mapped value of the given character
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public byte elementAt(char index)
{
return (values[(indices[index >> BLOCKSHIFT] & 0xFFFF)
+ (index & BLOCKMASK)]);
}
/**
* Set a new value for a Unicode character.
* Set automatically expands the array if it is compacted.
* @param index the character to set the mapped value with
* @param value the new mapped value
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public void setElementAt(char index, byte value)
{
if (isCompact)
expand();
values[index] = value;
touchBlock(index >> BLOCKSHIFT, value);
}
/**
* Set new values for a range of Unicode character.
*
* @param start the starting offset of the range
* @param end the ending offset of the range
* @param value the new mapped value
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public void setElementAt(char start, char end, byte value)
{
int i;
if (isCompact) {
expand();
}
for (i = start; i <= end; ++i) {
values[i] = value;
touchBlock(i >> BLOCKSHIFT, value);
}
}
/**
* Compact the array.
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public void compact() {
compact(false);
}
/**
* Compact the array.
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public void compact(boolean exhaustive)
{
if (!isCompact) {
int limitCompacted = 0;
int iBlockStart = 0;
char iUntouched = 0xFFFF;
for (int i = 0; i < indices.length; ++i, iBlockStart += BLOCKCOUNT) {
indices[i] = 0xFFFF;
boolean touched = blockTouched(i);
if (!touched && iUntouched != 0xFFFF) {
// If no values in this block were set, we can just set its
// index to be the same as some other block with no values
// set, assuming we've seen one yet.
indices[i] = iUntouched;
} else {
int jBlockStart = 0;
int j = 0;
for (j = 0; j < limitCompacted;
++j, jBlockStart += BLOCKCOUNT) {
if (hashes[i] == hashes[j] &&
arrayRegionMatches(values, iBlockStart,
values, jBlockStart, BLOCKCOUNT)) {
indices[i] = (char)jBlockStart;
break;
}
}
if (indices[i] == 0xFFFF) {
// we didn't match, so copy & update
System.arraycopy(values, iBlockStart,
values, jBlockStart, BLOCKCOUNT);
indices[i] = (char)jBlockStart;
hashes[j] = hashes[i];
++limitCompacted;
if (!touched) {
// If this is the first untouched block we've seen,
// remember its index.
iUntouched = (char)jBlockStart;
}
}
}
}
// we are done compacting, so now make the array shorter
int newSize = limitCompacted*BLOCKCOUNT;
byte[] result = new byte[newSize];
System.arraycopy(values, 0, result, 0, newSize);
values = result;
isCompact = true;
hashes = null;
}
}
/**
* Convenience utility to compare two arrays of doubles.
* @param len the length to compare.
* The start indices and start+len must be valid.
*/
final static boolean arrayRegionMatches(byte[] source, int sourceStart,
byte[] target, int targetStart,
int len)
{
int sourceEnd = sourceStart + len;
int delta = targetStart - sourceStart;
for (int i = sourceStart; i < sourceEnd; i++) {
if (source[i] != target[i + delta])
return false;
}
return true;
}
/**
* Remember that a specified block was "touched", i.e. had a value set.
* Untouched blocks can be skipped when compacting the array
*/
private final void touchBlock(int i, int value) {
hashes[i] = (hashes[i] + (value<<1)) | 1;
}
/**
* Query whether a specified block was "touched", i.e. had a value set.
* Untouched blocks can be skipped when compacting the array
*/
private final boolean blockTouched(int i) {
return hashes[i] != 0;
}
/**
* For internal use only. Do not modify the result, the behavior of
* modified results are undefined.
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public char[] getIndexArray()
{
return indices;
}
/**
* For internal use only. Do not modify the result, the behavior of
* modified results are undefined.
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated
public byte[] getValueArray()
{
return values;
}
/**
* Overrides Cloneable
* @internal
* @deprecated This API is ICU internal only.
*/
@Override
@Deprecated
public Object clone()
{
try {
CompactByteArray other = (CompactByteArray) super.clone();
other.values = values.clone();
other.indices = indices.clone();
if (hashes != null) other.hashes = hashes.clone();
return other;
} catch (CloneNotSupportedException e) {
throw new ICUCloneNotSupportedException(e);
}
}
/**
* Compares the equality of two compact array objects.
* @param obj the compact array object to be compared with this.
* @return true if the current compact array object is the same
* as the compact array object obj; false otherwise.
* @internal
* @deprecated This API is ICU internal only.
*/
@Override
@Deprecated
public boolean equals(Object obj) {
if (obj == null) return false;
if (this == obj) // quick check
return true;
if (getClass() != obj.getClass()) // same class?
return false;
CompactByteArray other = (CompactByteArray) obj;
for (int i = 0; i < UNICODECOUNT; i++) {
// could be sped up later
if (elementAt((char)i) != other.elementAt((char)i))
return false;
}
return true; // we made it through the guantlet.
}
/**
* Generates the hash code for the compact array object
* @internal
* @deprecated This API is ICU internal only.
*/
@Override
@Deprecated
public int hashCode() {
int result = 0;
int increment = Math.min(3, values.length/16);
for (int i = 0; i < values.length; i+= increment) {
result = result * 37 + values[i];
}
return result;
}
// --------------------------------------------------------------
// private
// --------------------------------------------------------------
/**
* Expanding takes the array back to a 65536 element array.
*/
private void expand()
{
int i;
if (isCompact) {
byte[] tempArray;
hashes = new int[INDEXCOUNT];
tempArray = new byte[UNICODECOUNT];
for (i = 0; i < UNICODECOUNT; ++i) {
byte value = elementAt((char)i);
tempArray[i] = value;
touchBlock(i >> BLOCKSHIFT, value);
}
for (i = 0; i < INDEXCOUNT; ++i) {
indices[i] = (char)(i< © 2015 - 2024 Weber Informatics LLC | Privacy Policy