org.graalvm.shadowed.com.ibm.icu.impl

Class TrieBuilder

java.lang.Object

org.graalvm.shadowed.com.ibm.icu.impl.TrieBuilder

Direct Known Subclasses:

IntTrieBuilder

public class TrieBuilder
extends Object

Builder class to manipulate and generate a trie. This is useful for ICU data in primitive 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 trie of any primitive data type serves two purposes:

• Fast access of the indexed values.
• Smaller memory footprint.

This is a direct port from the ICU4C version

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	TrieBuilder.DataManipulate Character data in com.ibm.impl.Trie have different user-specified format for different purposes.

Field Summary

Fields

Modifier and Type	Field and Description
protected static int	BMP_INDEX_LENGTH_ Length of the BMP portion of the index (stage 1) array.
static int	DATA_BLOCK_LENGTH Number of data values in a stage 2 (data array) block.
protected static int	DATA_GRANULARITY_ The alignment size of a stage 2 data block.
protected static int	INDEX_SHIFT_ Shift size for shifting left the index array values.
protected int	m_dataCapacity_
protected int	m_dataLength_
protected int[]	m_index_ Index values at build-time are 32 bits wide for easier processing.
protected int	m_indexLength_
protected boolean	m_isCompacted_
protected boolean	m_isLatin1Linear_
protected int[]	m_map_ Map of adjusted indexes, used in utrie_compact().
protected static int	MASK_ Mask for getting the lower bits from the input index.
protected static int	MAX_DATA_LENGTH_ Maximum length of the runtime data (stage 2) array.
protected static int	MAX_INDEX_LENGTH_ Length of the index (stage 1) array before folding.
protected static int	OPTIONS_DATA_IS_32_BIT_ If set, then the data (stage 2) array is 32 bits wide.
protected static int	OPTIONS_INDEX_SHIFT_ Shifting to position the index value in options
protected static int	OPTIONS_LATIN1_IS_LINEAR_ If set, then Latin-1 data (for U+0000..U+00ff) is stored in the data (stage 2) array as a simple, linear array at data + DATA_BLOCK_LENGTH.
protected static int	SHIFT_ Shift size for shifting right the input index.
protected static int	SURROGATE_BLOCK_COUNT_ Number of index (stage 1) entries per lead surrogate.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	TrieBuilder()
protected	TrieBuilder(TrieBuilder table)

Method Summary

Modifier and Type	Method and Description
protected static boolean	equal_int(int[] array, int start1, int start2, int length) Compare two sections of an array for equality.
protected static int	findSameIndexBlock(int[] index, int indexLength, int otherBlock) Finds the same index block as the otherBlock
protected void	findUnusedBlocks() Set a value in the trie index map to indicate which data block is referenced and which one is not.
boolean	isInZeroBlock(int ch) Checks if the character belongs to a zero block in the trie

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DATA_BLOCK_LENGTH

public static final int DATA_BLOCK_LENGTH

Number of data values in a stage 2 (data array) block. 2, 4, 8, .., 0x200

See Also:

Constant Field Values

m_index_

protected int[] m_index_

Index values at build-time are 32 bits wide for easier processing. Bit 31 is set if the data block is used by multiple index values (from setRange()).

m_indexLength_

protected int m_indexLength_

m_dataCapacity_

protected int m_dataCapacity_

m_dataLength_

protected int m_dataLength_

m_isLatin1Linear_

protected boolean m_isLatin1Linear_

m_isCompacted_

protected boolean m_isCompacted_

m_map_

protected int[] m_map_

Map of adjusted indexes, used in utrie_compact(). Maps from original indexes to new ones.

SHIFT_

protected static final int SHIFT_

Shift size for shifting right the input index. 1..9

See Also:

Constant Field Values

MAX_INDEX_LENGTH_

protected static final int MAX_INDEX_LENGTH_

Length of the index (stage 1) array before folding. Maximum number of Unicode code points (0x110000) shifted right by SHIFT.

See Also:

Constant Field Values

BMP_INDEX_LENGTH_

protected static final int BMP_INDEX_LENGTH_

Length of the BMP portion of the index (stage 1) array.

See Also:

Constant Field Values

SURROGATE_BLOCK_COUNT_

protected static final int SURROGATE_BLOCK_COUNT_

Number of index (stage 1) entries per lead surrogate. Same as number of indexe entries for 1024 trail surrogates, ==0x400>>UTRIE_SHIFT 10 - SHIFT == Number of bits of a trail surrogate that are used in index table lookups.

See Also:

Constant Field Values

MASK_

protected static final int MASK_

Mask for getting the lower bits from the input index. DATA_BLOCK_LENGTH - 1.

See Also:

Constant Field Values

INDEX_SHIFT_

protected static final int INDEX_SHIFT_

Shift size for shifting left the index array values. Increases possible data size with 16-bit index values at the cost of compactability. This requires blocks of stage 2 data to be aligned by UTRIE_DATA_GRANULARITY. 0..UTRIE_SHIFT

See Also:

Constant Field Values

MAX_DATA_LENGTH_

protected static final int MAX_DATA_LENGTH_

Maximum length of the runtime data (stage 2) array. Limited by 16-bit index values that are left-shifted by INDEX_SHIFT_.

See Also:

Constant Field Values

OPTIONS_INDEX_SHIFT_

protected static final int OPTIONS_INDEX_SHIFT_

Shifting to position the index value in options

See Also:

Constant Field Values

OPTIONS_DATA_IS_32_BIT_

protected static final int OPTIONS_DATA_IS_32_BIT_

If set, then the data (stage 2) array is 32 bits wide.

See Also:

Constant Field Values

OPTIONS_LATIN1_IS_LINEAR_

protected static final int OPTIONS_LATIN1_IS_LINEAR_

If set, then Latin-1 data (for U+0000..U+00ff) is stored in the data (stage 2) array as a simple, linear array at data + DATA_BLOCK_LENGTH.

See Also:

Constant Field Values

DATA_GRANULARITY_

protected static final int DATA_GRANULARITY_

The alignment size of a stage 2 data block. Also the granularity for compaction.

See Also:

Constant Field Values

Constructor Detail

TrieBuilder

protected TrieBuilder()

TrieBuilder

protected TrieBuilder(TrieBuilder table)

Method Detail

isInZeroBlock

public boolean isInZeroBlock(int ch)

Checks if the character belongs to a zero block in the trie

Parameters:

ch - codepoint which data is to be retrieved

Returns:

true if ch is in the zero block

equal_int

protected static final boolean equal_int(int[] array,
                                         int start1,
                                         int start2,
                                         int length)

Compare two sections of an array for equality.

findUnusedBlocks

protected void findUnusedBlocks()

Set a value in the trie index map to indicate which data block is referenced and which one is not. utrie_compact() will remove data blocks that are not used at all. Set - 0 if it is used - -1 if it is not used

findSameIndexBlock

protected static final int findSameIndexBlock(int[] index,
                                              int indexLength,
                                              int otherBlock)

Finds the same index block as the otherBlock

Parameters:

index - array

indexLength - size of index

otherBlock -

Returns:

same index block