Package com.xceptance.xlt.api.util

Class XltCharBuffer

java.lang.Object
com.xceptance.xlt.api.util.XltCharBuffer
All Implemented Interfaces:
CharSequence, Comparable<XltCharBuffer>
public class XltCharBuffer extends Object implements CharSequence, Comparable<XltCharBuffer>
This class does not implement the CharBuffer of the JDK, but uses the idea of a shared character array with views. This is also a very unsafe implementation with as little as possible boundary checks to achieve the maximum speed possible. To enhance use, we implement CharSequence and hence can also do regex with it now. It also features common String and StringBuilder methods to make it versatile and avoid the typical overhead when doing conversions back and forth.
Since:
7.0

  • Field Details

    • EMPTY

      public static final XltCharBuffer EMPTY
      An empty static XltCharBuffer

  • Constructor Details

    • XltCharBuffer

      public XltCharBuffer(char[] src)
      New buffer from a raw char array
      Parameters:
      src - a char array

    • XltCharBuffer

      public XltCharBuffer(char[] src, int from, int length)
      A new buffer from a char array including a view port.
      Parameters:
      src - the char array, if is is null, we fix that silently
      from - from where to deliver the buffer
      length - how long should the buffer be

  • Method Details

    • empty

      public static XltCharBuffer empty()
      Just returns an empty buffer. This is a static object and not a new buffer every time, so apply caution.
      Returns:
      the empty buffer

    • charAt

      public char charAt(int pos)
      Return the character at a position. This code does not run any checks in regards to pos being correct (≥ 0, < length). This will automatically apply the view on the underlying array hence incorrect pos values might return something unexpected. So know what you do or else...
      Specified by:
      charAt in interface CharSequence
      Parameters:
      pos - the position to return
      Returns:
      the character at this position.

    • put

      public XltCharBuffer put(int pos, char c)
      Set a character at this position. Similarly to charAt, this does not check for correctness of pos in favor of speed.
      Parameters:
      pos - the pos to write to
      c - the character to set
      Returns:
      this instance so put can be chained

    • split

      public List<XltCharBuffer> split(char splitChar)
      Splits up this sequence into sub-sequences at splitChar markers excluding the marker
      Parameters:
      splitChar - the split character
      Returns:
      a list of the sub-sequences

    • peakAhead

      public char peakAhead(int pos)
      Looks ahead, otherwise returns 0. Only safety bound against ahead misses, not any behind misses
      Parameters:
      pos - the position to look at
      Returns:
      the content of the peaked pos or 0 if this position does not exist

    • viewByLength

      public XltCharBuffer viewByLength(int from, int length)
      Returns a new buffer with a view on the current. No copy is made. No runtime checks
      Parameters:
      from - start position
      length - length of the view port
      Returns:
      a new buffer

    • viewFromTo

      public XltCharBuffer viewFromTo(int from, int to)
      Returns a new buffer with a view on the current. No copy is made. No runtime checks
      Parameters:
      from - start position
      to - end position
      Returns:
      a new buffer

    • substring

      public XltCharBuffer substring(int from, int to)
      Creates a new buffer similar to a String.substring call. There is no copy created, we still look at the same buffer, but have a reduced view.
      Parameters:
      from - first position (inclusive)
      to - last position (exclusive)
      Returns:

    • substring

      public XltCharBuffer substring(int from)
      Creates a new buffer similar to a String.substring call from a position till the end
      Parameters:
      from - first position
      Returns:

    • valueOf

      public static XltCharBuffer valueOf(String s1, String s2)
      Creates a new char buffer by merging strings
      Parameters:
      s1 - string 1
      s2 - string 2
      Returns:
      the new charbuffer

    • valueOf

      public static XltCharBuffer valueOf(XltCharBuffer s1, XltCharBuffer s2)
      Creates a new char buffer by merging XltCharBuffers
      Parameters:
      s1 - buffer 1
      s2 - buffer 2
      Returns:
      the new charbuffer

    • valueOf

      public static XltCharBuffer valueOf(XltCharBuffer s1, char c)
      Creates a new char buffer by adding a single char
      Parameters:
      s1 -
      c -
      Returns:

    • valueOf

      public static XltCharBuffer valueOf(String s1, String s2, String s3)
      Creates a new char buffer by merging strings
      Parameters:
      s1 -
      s2 -
      s3 -
      Returns:

    • valueOf

      public static XltCharBuffer valueOf(XltCharBuffer s1, XltCharBuffer s2, XltCharBuffer s3)
      Creates a new char buffer by merging strings
      Parameters:
      s1 -
      s2 -
      s3 -
      Returns:

    • valueOf

      public static XltCharBuffer valueOf(String s1, String s2, String s3, String... more)
      Creates a new char buffer by merging strings
      Parameters:
      s1 - string 1
      s2 - string 2
      s3 - string 3
      more - more strings
      Returns:
      a new char buffer

    • valueOf

      public static XltCharBuffer valueOf(char[] s)
      Create a new char buffer from a char array without copying it. It assume that the full array is valid and because we don't copy, we don't have immutability!
      Parameters:
      s - the char array to use
      Returns:
      a new charbuffer instance

    • valueOf

      public static XltCharBuffer valueOf(String s)
      Create a new char buffer from a string. Because a string does provide array access, we use the returned copy by toCharArray to set up the char buffer.
      Parameters:
      s - the string to use
      Returns:
      a new charbuffer instance

    • toString

      public String toString()
      Just return the content of this buffer as string. This is of course a copy operation.
      Specified by:
      toString in interface CharSequence
      Overrides:
      toString in class Object
      Returns:
      a string representation of this buffer

    • toCharArray

      public char[] toCharArray()
      Returns a copy of the backing char array for the range of this buffer aka not more than needed
      Returns:
      a copy of the relevant portion of the backing array

    • indexOf

      public int indexOf(char c)
      Find the first occurrence of a char
      Parameters:
      c - the char to search
      Returns:
      the position or -1 otherwise

    • indexOf

      public int indexOf(XltCharBuffer s)
      Search for the first occurrence of another buffer in this buffer
      Parameters:
      s - the buffer to be search for
      Returns:
      the first found position or -1 if not found

    • indexOf

      public int indexOf(XltCharBuffer s, int fromIndex)
      Search for the first occurrence of another buffer in this buffer
      Parameters:
      s - the buffer to be search for
      Returns:
      the first found position or -1 if not found

    • endsWith

      public boolean endsWith(XltCharBuffer s)
      Checks whether or not a buffer ends with the content of another buffer
      Parameters:
      s - the buffer that has to be machting the end of this buffer
      Returns:
      true if the end matches, false otherwise

    • startsWith

      public boolean startsWith(XltCharBuffer s)
      Checks if the start of the buffer matches another buffer
      Parameters:
      s - the buffer to match the start against
      Returns:
      true if the start matches, false otherwise

    • lastIndexOf

      public int lastIndexOf(XltCharBuffer s)
      Returns the last occurrence of a buffer in this buffer
      Parameters:
      s - the buffer to looks for
      Returns:
      the position of the last occurrence or -1

    • lastIndexOf

      public int lastIndexOf(XltCharBuffer s, int from)
      Returns the last occurrence of a buffer in this starting from a certain offset and searching backwards(!) from there
      Parameters:
      s - the buffer to looks for
      from - the offset to start from
      Returns:
      the position of the last occurrence or -1

    • length

      public int length()
      Returns the length of this buffer
      Specified by:
      length in interface CharSequence

    • hashCode

      public int hashCode()
      Optimized hashcode calculation for large strings using all execution units of the CPU. This is a trade off between cpu and branches. Assumes we are not mutating... if we mutate, we would have to reset the hashCode Taken from JDK 19 - JDK-8282664, Code and Idea by Richard Startin https://twitter.com/richardstartin
      Overrides:
      hashCode in class Object
      Returns:
      the hash code

    • emptyWhenNull

      public static XltCharBuffer emptyWhenNull(XltCharBuffer s)
      Returns the empty string if the provided buffer is null the buffer otherwise

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object

    • subSequence

      public CharSequence subSequence(int start, int end)
      Specified by:
      subSequence in interface CharSequence

    • compareTo

      public int compareTo(XltCharBuffer other)
      Compares this object with the specified object for order. Returns a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

      The implementor must ensure sgn(x.compareTo(y)) == -sgn(y.compareTo(x)) for all x and y. (This implies that x.compareTo(y) must throw an exception iff y.compareTo(x) throws an exception.)

      Specified by:
      compareTo in interface Comparable<XltCharBuffer>
      Parameters:
      other - the buffer to compare to
      Returns:
      -1, if this is smaller than other, 0 if the same, 1 if this is larger

    • toDebugString

      public String toDebugString()