net.sf.saxon.tinytree
Class CompressedWhitespace

java.lang.Object
  net.sf.saxon.tinytree.CompressedWhitespace

All Implemented Interfaces:

CharSequence

public class CompressedWhitespace
extends Object
implements CharSequence

This class provides a compressed representation of a sequence of whitespace characters. The representation is a sequence of bytes: in each byte the top two bits indicate which whitespace character is used (x9, xA, xD, or x20) and the bottom six bits indicate the number of such characters. A zero byte is a filler. We don't compress the sequence if it would occupy more than 8 bytes, because that's the space we've got available in the TinyTree arrays.

Constructor Summary

CompressedWhitespace(long compressedValue)

Method Summary

char	charAt(int index) Returns the char value at the specified index.
static CharSequence	compress(CharSequence in) Attempt to compress a CharSequence
boolean	equals(Object obj) Indicates whether some other object is "equal to" this one.
long	getCompressedValue()
int	hashCode() Returns a hash code value for the object.
int	length()
CharSequence	subSequence(int start, int end) Returns a new CharSequence that is a subsequence of this sequence.
String	toString() Returns a string representation of the object.
FastStringBuffer	uncompress(FastStringBuffer buffer) Uncompress the whitespace to a FastStringBuffer
static void	uncompress(long value, FastStringBuffer buffer)
void	write(Writer writer) Write the value to a Writer
void	writeEscape(boolean[] specialChars, Writer writer) Write the value to a Writer with escaping of special characters

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

CompressedWhitespace

public CompressedWhitespace(long compressedValue)

Method Detail

compress

public static CharSequence compress(CharSequence in)

Attempt to compress a CharSequence

Parameters:

in - the CharSequence to be compressed

Returns:

the compressed sequence if it can be compressed; or the original CharSequence otherwise

uncompress

public FastStringBuffer uncompress(FastStringBuffer buffer)

Uncompress the whitespace to a FastStringBuffer

Parameters:

buffer - the buffer to which the whitespace is to be appended. The parameter may be null, in which case a new buffer is created.

Returns:

the FastStringBuffer to which the whitespace has been appended. If a buffer was supplied in the argument, this will be the same buffer.

uncompress

public static void uncompress(long value,
                              FastStringBuffer buffer)

getCompressedValue

public long getCompressedValue()

length

public int length()

Specified by:

length in interface CharSequence

charAt

public char charAt(int index)

Returns the char value at the specified index. An index ranges from zero to length() - 1. The first char value of the sequence is at index zero, the next at index one, and so on, as for array indexing.

If the char value specified by the index is a surrogate, the surrogate value is returned.

Specified by:

charAt in interface CharSequence

Parameters:

index - the index of the char value to be returned

Returns:

the specified char value

Throws:

IndexOutOfBoundsException - if the index argument is negative or not less than length()

subSequence

public CharSequence subSequence(int start,
                                int end)

Returns a new CharSequence that is a subsequence of this sequence. The subsequence starts with the char value at the specified index and ends with the char value at index end - 1. The length (in chars) of the returned sequence is end - start, so if start == end then an empty sequence is returned.

Specified by:

subSequence in interface CharSequence

Parameters:

start - the start index, inclusive

end - the end index, exclusive

Returns:

the specified subsequence

Throws:

IndexOutOfBoundsException - if start or end are negative, if end is greater than length(), or if start is greater than end

equals

public boolean equals(Object obj)

Indicates whether some other object is "equal to" this one.

Overrides:

equals in class Object

hashCode

public int hashCode()

Returns a hash code value for the object.

Overrides:

hashCode in class Object

toString

public String toString()

Returns a string representation of the object.

Specified by:

toString in interface CharSequence

Overrides:

toString in class Object

write

public void write(Writer writer)
           throws IOException

Write the value to a Writer

Throws:

IOException

writeEscape

public void writeEscape(boolean[] specialChars,
                        Writer writer)
                 throws IOException

Write the value to a Writer with escaping of special characters

Throws:

IOException