Package org.apache.catalina.tribes.io

Class XByteBuffer

  • All Implemented Interfaces:
    java.io.Serializable
    public class XByteBuffer
extends java.lang.Object
implements java.io.Serializable
    The XByteBuffer provides a dual functionality. One, it stores message bytes and automatically extends the byte buffer if needed.
    Two, it can encode and decode packages so that they can be defined and identified as they come in on a socket.
    THIS CLASS IS NOT THREAD SAFE

    Transfer package:
    • START_DATA- 7 bytes - FLT2002
    • SIZE - 4 bytes - size of the data package
    • DATA - should be as many bytes as the prev SIZE
    • END_DATA - 7 bytes - TLF2003
    See Also:
    Serialized Form

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected byte[] buf
      Variable to hold the data
      protected int bufSize
      Current length of data in the buffer
      protected boolean discard
      Flag for discarding invalid packages If this flag is set to true, and append(byte[],...) is called, the data added will be inspected, and if it doesn't start with START_DATA it will be thrown away.
      protected static StringManager sm
      String manager for this class.

    • Constructor Summary

      Constructors 
      Constructor Description
      XByteBuffer​(byte[] data, boolean discard)
      Constructs a new XByteBuffer from the given data.
      XByteBuffer​(byte[] data, int size, boolean discard)
      Constructs a new XByteBuffer from the given data with a specific buffer size.
      XByteBuffer​(int size, boolean discard)
      Constructs a new XByteBuffer.
      TODO use a pool of byte[] for performance

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean append​(boolean i)
      Appends a boolean value to the buffer.
      boolean append​(byte i)
      Appends a single byte to the buffer.
      boolean append​(byte[] b, int off, int len)
      Appends a portion of a byte array to the buffer.
      boolean append​(int i)
      Appends an integer value to the buffer.
      boolean append​(long i)
      Appends a long value to the buffer.
      boolean append​(java.nio.ByteBuffer b, int len)
      Appends the data to the buffer.
      void clear()
      Resets the buffer
      int countPackages()
      Internal mechanism to make a check if a complete package exists within the buffer
      int countPackages​(boolean first)
      Counts the number of complete packages in the buffer.
      static byte[] createDataPackage​(byte[] data)
      Creates a complete data package from the given data.
      static byte[] createDataPackage​(byte[] data, int doff, int dlength, byte[] buffer, int bufoff)
      Creates a complete data package with header, size, data, and footer, writing to a provided buffer.
      static byte[] createDataPackage​(ChannelData cdata)
      Creates a complete data package
      static java.io.Serializable deserialize​(byte[] data)
      Deserializes a Serializable object from the given byte array.
      static java.io.Serializable deserialize​(byte[] data, int offset, int length)
      Deserializes a Serializable object from a portion of the given byte array.
      static java.io.Serializable deserialize​(byte[] data, int offset, int length, java.lang.ClassLoader[] cls)
      Deserializes a Serializable object from a portion of the given byte array using the specified class loaders.
      boolean doesPackageExist()
      Method to check if a package exists in this byte buffer.
      void expand​(int newcount)
      Expands the internal buffer to accommodate the specified number of bytes.
      XByteBuffer extractDataPackage​(boolean clearFromBuffer)
      Extracts the message bytes from a package.
      ChannelData extractPackage​(boolean clearFromBuffer)
      Extracts a complete package from the buffer and deserializes it into a ChannelData object.
      static int firstIndexOf​(byte[] src, int srcOff, byte[] find)
      Similar to a String.IndexOf, but uses pure bytes.
      byte[] getBytes()
      Returns the bytes in the buffer, in its exact length.
      byte[] getBytesDirect()
      Returns the internal byte array directly, without copying.
      int getCapacity()
      Returns the current capacity of the internal buffer.
      static int getDataPackageLength​(int datalength)
      Calculates the total length of a data package including header, size indicator, data, and footer.
      boolean getDiscard()
      Returns the discard flag for invalid packages.
      int getLength()
      Returns the current length of the data in the buffer.
      void reset()
      Resets the buffer length to zero.
      static byte[] serialize​(java.io.Serializable msg)
      Serializes a message into cluster data
      void setDiscard​(boolean discard)
      Sets the discard flag for invalid packages.
      void setLength​(int size)
      Sets the current length of the data in the buffer.
      static boolean toBoolean​(byte[] b, int offset)
      Converts a byte array entry to boolean.
      static byte[] toBytes​(boolean bool, byte[] data, int offset)
      Converts a boolean and put it in a byte array.
      static byte[] toBytes​(int n, byte[] b, int offset)
      Converts an integer to four bytes.
      static byte[] toBytes​(long n, byte[] b, int offset)
      Converts a long to eight bytes.
      static int toInt​(byte[] b, int off)
      Convert four bytes to an int
      static long toLong​(byte[] b, int off)
      Convert eight bytes to a long
      void trim​(int length)
      Trims the specified number of bytes from the end of the buffer.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • sm

        protected static final StringManager sm
        String manager for this class.

      • buf

        protected byte[] buf
        Variable to hold the data

      • bufSize

        protected int bufSize
        Current length of data in the buffer

      • discard

        protected boolean discard
        Flag for discarding invalid packages If this flag is set to true, and append(byte[],...) is called, the data added will be inspected, and if it doesn't start with START_DATA it will be thrown away.

    • Constructor Detail

      • XByteBuffer

        public XByteBuffer​(int size,
                   boolean discard)
        Constructs a new XByteBuffer.
        TODO use a pool of byte[] for performance
        Parameters:
        size - the initial size of the byte buffer
        discard - Flag for discarding invalid packages

      • XByteBuffer

        public XByteBuffer​(byte[] data,
                   boolean discard)
        Constructs a new XByteBuffer from the given data.
        Parameters:
        data - the initial data
        discard - Flag for discarding invalid packages

      • XByteBuffer

        public XByteBuffer​(byte[] data,
                   int size,
                   boolean discard)
        Constructs a new XByteBuffer from the given data with a specific buffer size.
        Parameters:
        data - the initial data
        size - the initial size of the byte buffer
        discard - Flag for discarding invalid packages

    • Method Detail

      • getLength

        public int getLength()
        Returns the current length of the data in the buffer.
        Returns:
        the current length

      • setLength

        public void setLength​(int size)
        Sets the current length of the data in the buffer.
        Parameters:
        size - the new length

      • trim

        public void trim​(int length)
        Trims the specified number of bytes from the end of the buffer.
        Parameters:
        length - the number of bytes to trim

      • reset

        public void reset()
        Resets the buffer length to zero.

      • getBytesDirect

        public byte[] getBytesDirect()
        Returns the internal byte array directly, without copying.
        Returns:
        the internal byte array

      • getBytes

        public byte[] getBytes()
        Returns the bytes in the buffer, in its exact length.
        Returns:
        The bytes in the buffer

      • clear

        public void clear()
        Resets the buffer

      • append

        public boolean append​(java.nio.ByteBuffer b,
                      int len)
        Appends the data to the buffer. If the data is incorrectly formatted, ie, the data should always start with the header, false will be returned and the data will be discarded.
        Parameters:
        b - - bytes to be appended
        len - - the number of bytes to append.
        Returns:
        true if the data was appended correctly. Returns false if the package is incorrect, ie missing header or something, or the length of data is 0

      • append

        public boolean append​(byte i)
        Appends a single byte to the buffer.
        Parameters:
        i - the byte to append
        Returns:
        always returns true

      • append

        public boolean append​(boolean i)
        Appends a boolean value to the buffer.
        Parameters:
        i - the boolean to append
        Returns:
        always returns true

      • append

        public boolean append​(long i)
        Appends a long value to the buffer.
        Parameters:
        i - the long to append
        Returns:
        always returns true

      • append

        public boolean append​(int i)
        Appends an integer value to the buffer.
        Parameters:
        i - the integer to append
        Returns:
        always returns true

      • append

        public boolean append​(byte[] b,
                      int off,
                      int len)
        Appends a portion of a byte array to the buffer.
        Parameters:
        b - the byte array
        off - the offset in the byte array
        len - the number of bytes to append
        Returns:
        true if data was appended, false if length is zero

      • expand

        public void expand​(int newcount)
        Expands the internal buffer to accommodate the specified number of bytes.
        Parameters:
        newcount - the new minimum capacity required

      • getCapacity

        public int getCapacity()
        Returns the current capacity of the internal buffer.
        Returns:
        the buffer capacity

      • countPackages

        public int countPackages()
        Internal mechanism to make a check if a complete package exists within the buffer
        Returns:
        - true if a complete package (header,compress,size,data,footer) exists within the buffer

      • countPackages

        public int countPackages​(boolean first)
        Counts the number of complete packages in the buffer.
        Parameters:
        first - if true, only check for the first package
        Returns:
        the number of complete packages found

      • doesPackageExist

        public boolean doesPackageExist()
        Method to check if a package exists in this byte buffer.
        Returns:
        - true if a complete package (header,options,size,data,footer) exists within the buffer

      • extractDataPackage

        public XByteBuffer extractDataPackage​(boolean clearFromBuffer)
        Extracts the message bytes from a package. If no package exists, a IllegalStateException will be thrown.
        Parameters:
        clearFromBuffer - - if true, the package will be removed from the byte buffer
        Returns:
        - returns the actual message bytes (header, compress,size and footer not included).

      • extractPackage

        public ChannelData extractPackage​(boolean clearFromBuffer)
        Extracts a complete package from the buffer and deserializes it into a ChannelData object.
        Parameters:
        clearFromBuffer - if true, the extracted package will be removed from the buffer
        Returns:
        the deserialized ChannelData object

      • createDataPackage

        public static byte[] createDataPackage​(ChannelData cdata)
        Creates a complete data package
        Parameters:
        cdata - - the message data to be contained within the package
        Returns:
        - a full package (header,size,data,footer)

      • createDataPackage

        public static byte[] createDataPackage​(byte[] data,
                                       int doff,
                                       int dlength,
                                       byte[] buffer,
                                       int bufoff)
        Creates a complete data package with header, size, data, and footer, writing to a provided buffer.
        Parameters:
        data - the data to package
        doff - the offset in the data array
        dlength - the length of the data
        buffer - the output buffer
        bufoff - the offset in the output buffer
        Returns:
        the output buffer

      • getDataPackageLength

        public static int getDataPackageLength​(int datalength)
        Calculates the total length of a data package including header, size indicator, data, and footer.
        Parameters:
        datalength - the length of the data portion
        Returns:
        the total package length

      • createDataPackage

        public static byte[] createDataPackage​(byte[] data)
        Creates a complete data package from the given data.
        Parameters:
        data - the data to package
        Returns:
        a full package (header, size, data, footer)

      • toInt

        public static int toInt​(byte[] b,
                        int off)
        Convert four bytes to an int
        Parameters:
        b - - the byte array containing the four bytes
        off - - the offset
        Returns:
        the integer value constructed from the four bytes

      • toLong

        public static long toLong​(byte[] b,
                          int off)
        Convert eight bytes to a long
        Parameters:
        b - - the byte array containing the four bytes
        off - - the offset
        Returns:
        the long value constructed from the eight bytes

      • toBytes

        public static byte[] toBytes​(boolean bool,
                             byte[] data,
                             int offset)
        Converts a boolean and put it in a byte array.
        Parameters:
        bool - the integer
        data - the byte buffer in which the boolean will be placed
        offset - the offset in the byte array
        Returns:
        the byte array

      • toBoolean

        public static boolean toBoolean​(byte[] b,
                                int offset)
        Converts a byte array entry to boolean.
        Parameters:
        b - byte array
        offset - within byte array
        Returns:
        true if byte array entry is non-zero, false otherwise

      • toBytes

        public static byte[] toBytes​(int n,
                             byte[] b,
                             int offset)
        Converts an integer to four bytes.
        Parameters:
        n - the integer
        b - the byte buffer in which the integer will be placed
        offset - the offset in the byte array
        Returns:
        four bytes in an array

      • toBytes

        public static byte[] toBytes​(long n,
                             byte[] b,
                             int offset)
        Converts a long to eight bytes.
        Parameters:
        n - the long
        b - the byte buffer in which the integer will be placed
        offset - the offset in the byte array
        Returns:
        eight bytes in an array

      • firstIndexOf

        public static int firstIndexOf​(byte[] src,
                               int srcOff,
                               byte[] find)
        Similar to a String.IndexOf, but uses pure bytes.
        Parameters:
        src - - the source bytes to be searched
        srcOff - - offset on the source buffer
        find - - the string to be found within src
        Returns:
        - the index of the first matching byte. -1 if the find array is not found

      • deserialize

        public static java.io.Serializable deserialize​(byte[] data)
                                        throws java.io.IOException,
                                               java.lang.ClassNotFoundException,
                                               java.lang.ClassCastException
        Deserializes a Serializable object from the given byte array.
        Parameters:
        data - the byte array containing the serialized object
        Returns:
        the deserialized object
        Throws:
        java.io.IOException - if an I/O error occurs
        java.lang.ClassNotFoundException - if the class of the serialized object cannot be found
        java.lang.ClassCastException - if the deserialized object is not Serializable

      • deserialize

        public static java.io.Serializable deserialize​(byte[] data,
                                               int offset,
                                               int length)
                                        throws java.io.IOException,
                                               java.lang.ClassNotFoundException,
                                               java.lang.ClassCastException
        Deserializes a Serializable object from a portion of the given byte array.
        Parameters:
        data - the byte array containing the serialized object
        offset - the offset in the byte array
        length - the length of the data to deserialize
        Returns:
        the deserialized object
        Throws:
        java.io.IOException - if an I/O error occurs
        java.lang.ClassNotFoundException - if the class of the serialized object cannot be found
        java.lang.ClassCastException - if the deserialized object is not Serializable

      • deserialize

        public static java.io.Serializable deserialize​(byte[] data,
                                               int offset,
                                               int length,
                                               java.lang.ClassLoader[] cls)
                                        throws java.io.IOException,
                                               java.lang.ClassNotFoundException,
                                               java.lang.ClassCastException
        Deserializes a Serializable object from a portion of the given byte array using the specified class loaders.
        Parameters:
        data - the byte array containing the serialized object
        offset - the offset in the byte array
        length - the length of the data to deserialize
        cls - the class loaders to use for deserialization
        Returns:
        the deserialized object
        Throws:
        java.io.IOException - if an I/O error occurs
        java.lang.ClassNotFoundException - if the class of the serialized object cannot be found
        java.lang.ClassCastException - if the deserialized object is not Serializable

      • serialize

        public static byte[] serialize​(java.io.Serializable msg)
                        throws java.io.IOException
        Serializes a message into cluster data
        Parameters:
        msg - ClusterMessage
        Returns:
        serialized content as byte[] array
        Throws:
        java.io.IOException - Serialization error

      • setDiscard

        public void setDiscard​(boolean discard)
        Sets the discard flag for invalid packages.
        Parameters:
        discard - the new discard flag value

      • getDiscard

        public boolean getDiscard()
        Returns the discard flag for invalid packages.
        Returns:
        the discard flag value