Package net.sf.saxon.tree.util

Class FastStringBuffer

  • All Implemented Interfaces:
    java.lang.CharSequence, AppendableCharSequence, CharSequenceConsumer
    public final class FastStringBuffer
extends java.lang.Object
implements AppendableCharSequence, CharSequenceConsumer
    A simple implementation of a class similar to StringBuffer. Unlike StringBuffer it is not synchronized. It also offers the capability to remove unused space. (This class could possibly be replaced by StringBuilder in JDK 1.5, but using our own class gives more control.)

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int C1024  
      static int C16  
      static int C256  
      static int C64  

    • Constructor Summary

      Constructors 
      Constructor Description
      FastStringBuffer​(int initialSize)
      Create a FastStringBuffer with a given initial capacity
      FastStringBuffer​(java.lang.CharSequence cs)
      Create a FastStringBuffer with initial content

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void append​(char[] srcArray)
      Append the entire contents of a character array to the buffer
      void append​(char[] srcArray, int start, int length)
      Append the contents of a character array to the buffer
      void append​(java.lang.CharSequence s)
      Append the contents of a general CharSequence to the buffer
      void append​(java.lang.String s)
      Append the contents of a String to the buffer
      void append​(java.lang.StringBuffer s)
      Append the contents of a StringBuffer to the buffer
      void append​(UnicodeString str)
      Append a UnicodeString to the buffer (using surrogate pairs if necessary)
      void append​(CharSlice s)
      Append the contents of a CharSlice to the buffer
      void append​(FastStringBuffer s)
      Append the contents of a FastStringBuffer to the buffer
      void appendWideChar​(int ch)
      Append a wide character to the buffer (as a surrogate pair if necessary)
      FastStringBuffer cat​(char ch)
      Append a character to the buffer
      FastStringBuffer cat​(java.lang.CharSequence s)
      Append the contents of a general CharSequence to the buffer
      FastStringBuffer cat​(java.lang.String s)
      Append the contents of a String to the buffer
      char charAt​(int index)
      Returns the char value at the specified index.
      FastStringBuffer condense()
      Remove surplus space from the array.
      static java.lang.String diagnosticPrint​(java.lang.CharSequence in)
      Diagnostic print of the contents of a CharSequence.
      void ensureCapacity​(int extra)
      Expand the character array if necessary to ensure capacity for appended data
      boolean equals​(java.lang.Object other)
      Compare equality
      void getChars​(int srcBegin, int srcEnd, char[] dst, int dstBegin)
      Copies characters from this FastStringBuffer into the destination character array.
      int hashCode()
      Generate a hash code
      int indexOf​(char ch)
      Get the index of the first character equal to a given value
      void insert​(int index, char ch)
      Insert a character at a particular offset
      void insertWideChar​(int index, int ch)
      Insert wide character at a particular offset
      boolean isEmpty()
      Ask whether the string buffer is empty
      int length()
      Returns the length of this character sequence.
      void prepend​(char ch)
      Insert a given character at the start of the buffer
      void prepend​(java.lang.CharSequence str)
      Insert a given string at the start of the buffer
      void prependRepeated​(char ch, int repeat)
      Insert a given character N times at the start of the buffer
      void prependWideChar​(int ch)
      Prepend a wide character to the buffer (as a surrogate pair if necessary)
      void removeCharAt​(int index)
      Remove a character at a particular offset
      void setCharAt​(int index, char ch)
      Set the character at a particular offset
      void setLength​(int length)
      Set the length.
      java.lang.CharSequence subSequence​(int start, int end)
      Returns a new CharSequence that is a subsequence of this sequence.
      char[] toCharArray()
      Get a char[] array containing the characters.
      java.lang.String toString()
      Convert contents of the FastStringBuffer to a string
      void write​(java.io.Writer writer)
      Write the value to a writer

      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait

      • Methods inherited from interface java.lang.CharSequence

        chars, codePoints

    • Constructor Detail

      • FastStringBuffer

        public FastStringBuffer​(int initialSize)
        Create a FastStringBuffer with a given initial capacity
        Parameters:
        initialSize - the initial capacity

      • FastStringBuffer

        public FastStringBuffer​(java.lang.CharSequence cs)
        Create a FastStringBuffer with initial content
        Parameters:
        cs - the initial content. The buffer is created with just enough capacity for this content (it will be expanded if more content is added later).

    • Method Detail

      • cat

        public FastStringBuffer cat​(java.lang.String s)
        Append the contents of a String to the buffer
        Parameters:
        s - the String to be appended
        Returns:
        the FastStringBuffer with the new contents

      • append

        public void append​(java.lang.String s)
        Append the contents of a String to the buffer
        Parameters:
        s - the String to be appended

      • append

        public void append​(CharSlice s)
        Append the contents of a CharSlice to the buffer
        Parameters:
        s - the String to be appended

      • append

        public void append​(FastStringBuffer s)
        Append the contents of a FastStringBuffer to the buffer
        Parameters:
        s - the FastStringBuffer to be appended

      • append

        public void append​(java.lang.StringBuffer s)
        Append the contents of a StringBuffer to the buffer
        Parameters:
        s - the StringBuffer to be appended

      • cat

        public FastStringBuffer cat​(java.lang.CharSequence s)
        Append the contents of a general CharSequence to the buffer
        Specified by:
        cat in interface AppendableCharSequence
        Specified by:
        cat in interface CharSequenceConsumer
        Parameters:
        s - the CharSequence to be appended
        Returns:
        the result of the concatenation

      • append

        public void append​(java.lang.CharSequence s)
        Append the contents of a general CharSequence to the buffer
        Parameters:
        s - the CharSequence to be appended

      • append

        public void append​(char[] srcArray,
                   int start,
                   int length)
        Append the contents of a character array to the buffer
        Parameters:
        srcArray - the array whose contents are to be added
        start - the offset of the first character in the array to be copied
        length - the number of characters to be copied

      • append

        public void append​(char[] srcArray)
        Append the entire contents of a character array to the buffer
        Parameters:
        srcArray - the array whose contents are to be added

      • appendWideChar

        public void appendWideChar​(int ch)
        Append a wide character to the buffer (as a surrogate pair if necessary)
        Parameters:
        ch - the character, as a 32-bit Unicode codepoint

      • append

        public void append​(UnicodeString str)
        Append a UnicodeString to the buffer (using surrogate pairs if necessary)
        Parameters:
        str - the UnicodeString

      • prependWideChar

        public void prependWideChar​(int ch)
        Prepend a wide character to the buffer (as a surrogate pair if necessary)
        Parameters:
        ch - the character, as a 32-bit Unicode codepoint

      • length

        public int length()
        Returns the length of this character sequence. The length is the number of 16-bit chars in the sequence.
        Specified by:
        length in interface java.lang.CharSequence
        Returns:
        the number of chars in this sequence

      • isEmpty

        public boolean isEmpty()
        Ask whether the string buffer is empty
        Returns:
        true if the buffer is empty (length()==0)

      • 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 java.lang.CharSequence
        Parameters:
        index - the index of the char value to be returned
        Returns:
        the specified char value
        Throws:
        java.lang.IndexOutOfBoundsException - if the index argument is negative or not less than length()

      • subSequence

        public java.lang.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 java.lang.CharSequence
        Parameters:
        start - the start index, inclusive
        end - the end index, exclusive
        Returns:
        the specified subsequence
        Throws:
        java.lang.IndexOutOfBoundsException - if start or end are negative, if end is greater than length(), or if start is greater than end

      • getChars

        public void getChars​(int srcBegin,
                     int srcEnd,
                     char[] dst,
                     int dstBegin)
        Copies characters from this FastStringBuffer into the destination character array.

        The first character to be copied is at index srcBegin; the last character to be copied is at index srcEnd-1 (thus the total number of characters to be copied is srcEnd-srcBegin). The characters are copied into the subarray of dst starting at index dstBegin and ending at index:

             dstbegin + (srcEnd-srcBegin) - 1
        Parameters:
        srcBegin - index of the first character in the string to copy.
        srcEnd - index after the last character in the string to copy.
        dst - the destination array.
        dstBegin - the start offset in the destination array.
        Throws:
        java.lang.IndexOutOfBoundsException - If any of the following is true:
        • srcBegin is negative.
        • srcBegin is greater than srcEnd
        • srcEnd is greater than the length of this string
        • dstBegin is negative
        • dstBegin+(srcEnd-srcBegin) is larger than dst.length

      • indexOf

        public int indexOf​(char ch)
        Get the index of the first character equal to a given value
        Parameters:
        ch - the character to search for
        Returns:
        the position of the first occurrence, or -1 if not found

      • toString

        public java.lang.String toString()
        Convert contents of the FastStringBuffer to a string
        Specified by:
        toString in interface java.lang.CharSequence
        Overrides:
        toString in class java.lang.Object

      • equals

        public boolean equals​(java.lang.Object other)
        Compare equality
        Overrides:
        equals in class java.lang.Object

      • hashCode

        public int hashCode()
        Generate a hash code
        Overrides:
        hashCode in class java.lang.Object

      • toCharArray

        public char[] toCharArray()
        Get a char[] array containing the characters. The caller should not modify the array.
        Returns:
        a char[] array containing the characters.

      • setCharAt

        public void setCharAt​(int index,
                      char ch)
        Set the character at a particular offset
        Parameters:
        index - the index of the character to be set
        ch - the new character to overwrite the existing character at that location
        Throws:
        java.lang.IndexOutOfBoundsException - if int<0 or int>=length()

      • insert

        public void insert​(int index,
                   char ch)
        Insert a character at a particular offset
        Parameters:
        index - the index of the character to be set
        ch - the new character to insert at that location
        Throws:
        java.lang.IndexOutOfBoundsException - if int<0 or int>=length()

      • insertWideChar

        public void insertWideChar​(int index,
                           int ch)
        Insert wide character at a particular offset
        Parameters:
        index - the index of the character to be set
        ch - the character, as a 32-bit Unicode codepoint
        Throws:
        java.lang.IndexOutOfBoundsException - if int<0 or int>=length()

      • removeCharAt

        public void removeCharAt​(int index)
        Remove a character at a particular offset
        Parameters:
        index - the index of the character to be set
        Throws:
        java.lang.IndexOutOfBoundsException - if int<0 or int>=length()

      • prepend

        public void prepend​(char ch)
        Insert a given character at the start of the buffer
        Parameters:
        ch - the character to insert

      • prepend

        public void prepend​(java.lang.CharSequence str)
        Insert a given string at the start of the buffer
        Parameters:
        str - the string to insert

      • prependRepeated

        public void prependRepeated​(char ch,
                            int repeat)
        Insert a given character N times at the start of the buffer
        Parameters:
        ch - the character to insert
        repeat - the number of occurrences required. Supplying 0 or a negative number is OK, and is treated as a no-op.

      • setLength

        public void setLength​(int length)
        Set the length. If this exceeds the current length, this method is a no-op. If this is less than the current length, characters beyond the specified point are deleted.
        Specified by:
        setLength in interface AppendableCharSequence
        Parameters:
        length - the new length

      • ensureCapacity

        public void ensureCapacity​(int extra)
        Expand the character array if necessary to ensure capacity for appended data
        Parameters:
        extra - the amount of additional capacity needed, in characters

      • condense

        public FastStringBuffer condense()
        Remove surplus space from the array. This doesn't reduce the array to the minimum possible size; it only reclaims space if it seems worth doing. Specifically, it contracts the array if the amount of wasted space is more than 256 characters, or more than half the allocated size and more than 20 chars.
        Returns:
        the buffer after removing unused space

      • write

        public void write​(java.io.Writer writer)
           throws java.io.IOException
        Write the value to a writer
        Parameters:
        writer - the writer to which the content is to be written
        Throws:
        java.io.IOException

      • diagnosticPrint

        public static java.lang.String diagnosticPrint​(java.lang.CharSequence in)
        Diagnostic print of the contents of a CharSequence. Ordinary printable ASCII characters are displayed as themselves; anything else is displayed as a \\uNNNN escape sequence
        Parameters:
        in - the CharSequence whose contents are to be displayed.
        Returns:
        the diagnostic output