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 Details

    • CompressedWhitespace

      public CompressedWhitespace(long compressedValue)
  • Method Details

    • 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.
    • 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
    • main

      public static void main(String[] args)