## net.sf.saxon.tree.util
Class FastStringBuffer

    java.lang.Object
      net.sf.saxon.tree.util.FastStringBuffer

All Implemented Interfaces:
  Serializable, CharSequence, AppendableCharSequence

    public final class FastStringBuffer

extends Object
implements AppendableCharSequence, Serializable

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.)

See Also:
  Serialized Form

Field Summary
`static int` `LARGE`
`static int` `MEDIUM`
`static int` `SMALL`
`static int` `TINY`

Constructor Summary
`FastStringBuffer(CharSequence cs)` Create a FastStringBuffer with initial content
`FastStringBuffer(int initialSize)` Create a FastStringBuffer with a given initial capacity

Method Summary
`void` `append(char ch)` Append a character to the buffer
`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(CharSequence s)` Append the contents of a general CharSequence to the buffer
`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` `append(String s)` Append the contents of a String to the buffer
`void` `append(StringBuffer s)` Append the contents of a StringBuffer to the buffer
`void` `appendWideChar(int ch)` Append a wide character to the buffer (as a surrogate pair if necessary)
`char` `charAt(int index)` Returns the `char` value at the specified index.
`CharSequence` `condense()` Remove surplus space from the array.
`static String` `diagnosticPrint(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(Object other)` Compare equality
`char[]` `getCharArray()` Get a char[] array containing the characters.
`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` `insertCharAt(int index, char ch)` Insert a character at a particular offset
`void` `insertWideCharAt(int index, int ch)` Insert wide character at a particular offset
`int` `length()` Returns the length of this character sequence.
`void` `prepend(char ch)` Insert a given character 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.
`CharSequence` `subSequence(int start, int end)` Returns a new `CharSequence` that is a subsequence of this sequence.
`String` `toString()` Convert contents of the FastStringBuffer to a string
`void` `write(Writer writer)` Write the value to a writer

Methods inherited from class java.lang.Object
`clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

Field Detail

### TINY

    public static final int TINY

See Also:
  Constant Field Values

### SMALL

    public static final int SMALL

See Also:
  Constant Field Values

### MEDIUM

    public static final int MEDIUM

See Also:
  Constant Field Values

### LARGE

    public static final int LARGE

See Also:
  Constant Field Values

Constructor Detail

### FastStringBuffer

    public FastStringBuffer(int initialSize)

  Create a FastStringBuffer with a given initial capacity

  Parameters:
    `initialSize` - the initial capacity

### FastStringBuffer

    public FastStringBuffer(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

### append

    public void append(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(StringBuffer s)

  Append the contents of a StringBuffer to the buffer

  Parameters:
    `s` - the StringBuffer to be appended

### append

    public void append(CharSequence s)

  Append the contents of a general CharSequence to the buffer

  Specified by:
    `append` in interface `AppendableCharSequence`
  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

### append

    public void append(char ch)

  Append a character to the buffer

  Parameters:
    `ch` - the character 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

### 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 `char`s in the sequence.

  Specified by:
    `length` in interface `CharSequence`
  Returns:
    the number of `char`s in this sequence

### 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 `char`s) 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`

### 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:
    `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 String toString()

  Convert contents of the FastStringBuffer to a string

  Specified by:
    `toString` in interface `CharSequence`
  Overrides:
    `toString` in class `Object`

### equals

    public boolean equals(Object other)

  Compare equality

  Overrides:
    `equals` in class `Object`

### hashCode

    public int hashCode()

  Generate a hash code

  Overrides:
    `hashCode` in class `Object`

### getCharArray

    public char[] getCharArray()

  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:
    `IndexOutOfBoundsException` - if int<0 or int>=length()

### insertCharAt

    public void insertCharAt(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:
    `IndexOutOfBoundsException` - if int<0 or int>=length()

### insertWideCharAt

    public void insertWideCharAt(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:
    `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:
    `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

### 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 CharSequence 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(Writer writer)
               throws IOException

  Write the value to a writer

  Parameters:
    `writer` - the writer to which the content is to be written
  Throws:
    `IOException`

### diagnosticPrint

    public static String diagnosticPrint(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

Copyright (c) 2004-2010 Saxonica Limited. All rights reserved.