Package org.apache.cassandra.utils

Class ByteBufferUtil

  • public class ByteBufferUtil
extends java.lang.Object
    Utility methods to make ByteBuffers less painful The following should illustrate the different ways byte buffers can be used public void testArrayOffet() { byte[] b = "test_slice_array".getBytes(); ByteBuffer bb = ByteBuffer.allocate(1024); assert bb.position() == 0; assert bb.limit() == 1024; assert bb.capacity() == 1024; bb.put(b); assert bb.position() == b.length; assert bb.remaining() == bb.limit() - bb.position(); ByteBuffer bb2 = bb.slice(); assert bb2.position() == 0; //slice should begin at other buffers current position assert bb2.arrayOffset() == bb.position(); //to match the position in the underlying array one needs to //track arrayOffset assert bb2.limit()+bb2.arrayOffset() == bb.limit(); assert bb2.remaining() == bb.remaining(); } }

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.nio.ByteBuffer[] EMPTY_ARRAY  
      static java.nio.ByteBuffer EMPTY_BYTE_BUFFER  
      static java.nio.ByteBuffer UNSET_BYTE_BUFFER
      Represents an unset value in bound variables

    • Constructor Summary

      Constructors 
      Constructor Description
      ByteBufferUtil()  

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static java.nio.ByteBuffer bytes​(byte b)  
      static java.nio.ByteBuffer bytes​(double d)  
      static java.nio.ByteBuffer bytes​(float f)  
      static java.nio.ByteBuffer bytes​(int i)  
      static java.nio.ByteBuffer bytes​(long n)  
      static java.nio.ByteBuffer bytes​(short s)  
      static java.nio.ByteBuffer bytes​(java.lang.String s)
      Encode a String in a ByteBuffer using UTF_8.
      static java.nio.ByteBuffer bytes​(java.lang.String s, java.nio.charset.Charset charset)
      Encode a String in a ByteBuffer using the provided charset.
      static java.nio.ByteBuffer bytes​(java.net.InetAddress address)  
      static java.nio.ByteBuffer bytes​(java.util.UUID uuid)  
      static java.nio.ByteBuffer bytes​(TimeUUID uuid)  
      static java.lang.String bytesToHex​(java.nio.ByteBuffer bytes)  
      static boolean canMinimize​(java.nio.ByteBuffer buf)  
      static boolean canMinimize​(java.nio.ByteBuffer[] src)  
      static java.nio.ByteBuffer clone​(java.nio.ByteBuffer buffer)  
      static int compare​(byte[] o1, java.nio.ByteBuffer o2)  
      static int compare​(byte[] o1, java.nio.ByteBuffer o2, int s2, int l2)  
      static int compare​(java.nio.ByteBuffer o1, byte[] o2)  
      static int compare​(java.nio.ByteBuffer o1, int s1, int l1, byte[] o2)  
      static int compareSubArrays​(java.nio.ByteBuffer bytes1, int offset1, java.nio.ByteBuffer bytes2, int offset2, int length)
      Compare two ByteBuffer at specified offsets for length.
      static int compareUnsigned​(java.nio.ByteBuffer o1, java.nio.ByteBuffer o2)  
      static boolean contains​(java.nio.ByteBuffer buffer, java.nio.ByteBuffer subBuffer)
      Check is the given buffer contains a given sub-buffer.
      static void copyBytes​(java.nio.ByteBuffer src, int srcPos, byte[] dst, int dstPos, int length)
      Transfer bytes from a ByteBuffer to byte array.
      static void copyBytes​(java.nio.ByteBuffer src, int srcPos, java.nio.ByteBuffer dst, int dstPos, int length)
      Transfer bytes from one ByteBuffer to another.
      static boolean endsWith​(java.nio.ByteBuffer src, java.nio.ByteBuffer suffix)  
      static java.nio.ByteBuffer ensureCapacity​(java.nio.ByteBuffer buf, int outputLength, boolean allowBufferResize)
      Ensure buf is large enough for outputLength.
      static java.nio.ByteBuffer ensureCapacity​(java.nio.ByteBuffer buf, int outputLength, boolean allowBufferResize, BufferType bufferType)
      Ensure buf is large enough for outputLength.
      static boolean equalsWithShortLength​(java.io.DataInput in, java.nio.ByteBuffer toMatch)
      Returns true if the buffer at the current position in the input matches given buffer.
      static byte[] getArray​(java.nio.ByteBuffer buffer)
      You should almost never use this.
      static byte[] getArray​(java.nio.ByteBuffer buffer, int position, int length)
      You should almost never use this.
      static float getFloat​(java.nio.ByteBuffer bytes, int offset)  
      static int getShortLength​(java.nio.ByteBuffer bb, int position)  
      static int getUnsignedShort​(java.nio.ByteBuffer bb, int position)  
      static java.nio.ByteBuffer hexToBytes​(java.lang.String str)  
      static java.io.InputStream inputStream​(java.nio.ByteBuffer bytes)  
      static boolean isPrefix​(java.nio.ByteBuffer prefix, java.nio.ByteBuffer value)  
      static int lastIndexOf​(java.nio.ByteBuffer buffer, byte valueToFind, int startIndex)
      ByteBuffer adaptation of org.apache.commons.lang3.ArrayUtils.lastIndexOf method
      static java.nio.ByteBuffer minimalBufferFor​(java.nio.ByteBuffer buf)
      trims size of bytebuffer to exactly number of bytes in it, to do not hold too much memory
      static java.nio.ByteBuffer[] minimizeBuffers​(java.nio.ByteBuffer[] src)  
      static java.nio.ByteBuffer objectToBytes​(java.lang.Object obj)  
      static int put​(java.nio.ByteBuffer src, java.nio.ByteBuffer trg)  
      static java.nio.ByteBuffer read​(java.io.DataInput in, int length)  
      static byte[] readBytes​(java.io.DataInput in, int length)  
      static java.nio.ByteBuffer readBytes​(java.nio.ByteBuffer bb, int length)  
      static byte[] readBytesWithLength​(java.io.DataInput in)  
      static java.nio.ByteBuffer readBytesWithShortLength​(java.nio.ByteBuffer bb)  
      static void readFully​(java.nio.channels.FileChannel channel, java.nio.ByteBuffer dst, long position)  
      static int readShortLength​(java.io.DataInput in)  
      static int readShortLength​(java.nio.ByteBuffer bb)  
      static java.nio.ByteBuffer readWithLength​(java.io.DataInput in)  
      static java.nio.ByteBuffer readWithShortLength​(java.io.DataInput in)  
      static java.nio.ByteBuffer readWithVIntLength​(DataInputPlus in)  
      static int serializedSizeWithLength​(java.nio.ByteBuffer buffer)  
      static int serializedSizeWithShortLength​(java.nio.ByteBuffer buffer)  
      static int serializedSizeWithVIntLength​(java.nio.ByteBuffer buffer)  
      static void skipShortLength​(DataInputPlus in)  
      static void skipWithVIntLength​(DataInputPlus in)  
      static boolean startsWith​(java.nio.ByteBuffer src, java.nio.ByteBuffer prefix)  
      static java.lang.String string​(java.nio.ByteBuffer buffer)
      Decode a String representation.
      static java.lang.String string​(java.nio.ByteBuffer buffer, int position, int length)
      Decode a String representation.
      static java.lang.String string​(java.nio.ByteBuffer buffer, int position, int length, java.nio.charset.Charset charset)
      Decode a String representation.
      static java.lang.String string​(java.nio.ByteBuffer buffer, java.nio.charset.Charset charset)
      Decode a String representation.
      static byte toByte​(java.nio.ByteBuffer bytes)
      Convert a byte buffer to a short.
      static double toDouble​(java.nio.ByteBuffer bytes)  
      static float toFloat​(java.nio.ByteBuffer bytes)  
      static int toInt​(java.nio.ByteBuffer bytes)
      Convert a byte buffer to an integer.
      static long toLong​(java.nio.ByteBuffer bytes)  
      static short toShort​(java.nio.ByteBuffer bytes)
      Convert a byte buffer to a short.
      static void writeShortLength​(java.nio.ByteBuffer bb, int length)  
      static void writeWithLength​(java.nio.ByteBuffer bytes, DataOutputPlus out)  
      static void writeWithShortLength​(java.nio.ByteBuffer buffer, DataOutputPlus out)  
      static void writeWithVIntLength​(java.nio.ByteBuffer bytes, DataOutputPlus out)  
      static void writeZeroes​(java.nio.ByteBuffer dest, int count)  

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • EMPTY_BYTE_BUFFER

        public static final java.nio.ByteBuffer EMPTY_BYTE_BUFFER

      • UNSET_BYTE_BUFFER

        public static final java.nio.ByteBuffer UNSET_BYTE_BUFFER
        Represents an unset value in bound variables

      • EMPTY_ARRAY

        public static final java.nio.ByteBuffer[] EMPTY_ARRAY

    • Constructor Detail

      • ByteBufferUtil

        public ByteBufferUtil()

    • Method Detail

      • compareUnsigned

        @Inline
public static int compareUnsigned​(java.nio.ByteBuffer o1,
                                  java.nio.ByteBuffer o2)

      • compare

        @Inline
public static int compare​(byte[] o1,
                          java.nio.ByteBuffer o2)

      • compare

        @Inline
public static int compare​(java.nio.ByteBuffer o1,
                          byte[] o2)

      • compare

        public static int compare​(java.nio.ByteBuffer o1,
                          int s1,
                          int l1,
                          byte[] o2)

      • compare

        public static int compare​(byte[] o1,
                          java.nio.ByteBuffer o2,
                          int s2,
                          int l2)

      • string

        public static java.lang.String string​(java.nio.ByteBuffer buffer)
                               throws java.nio.charset.CharacterCodingException
        Decode a String representation. This method assumes that the encoding charset is UTF_8.
        Parameters:
        buffer - a byte buffer holding the string representation
        Returns:
        the decoded string
        Throws:
        java.nio.charset.CharacterCodingException

      • string

        public static java.lang.String string​(java.nio.ByteBuffer buffer,
                                      int position,
                                      int length)
                               throws java.nio.charset.CharacterCodingException
        Decode a String representation. This method assumes that the encoding charset is UTF_8.
        Parameters:
        buffer - a byte buffer holding the string representation
        position - the starting position in buffer to start decoding from
        length - the number of bytes from buffer to use
        Returns:
        the decoded string
        Throws:
        java.nio.charset.CharacterCodingException

      • string

        public static java.lang.String string​(java.nio.ByteBuffer buffer,
                                      int position,
                                      int length,
                                      java.nio.charset.Charset charset)
                               throws java.nio.charset.CharacterCodingException
        Decode a String representation.
        Parameters:
        buffer - a byte buffer holding the string representation
        position - the starting position in buffer to start decoding from
        length - the number of bytes from buffer to use
        charset - the String encoding charset
        Returns:
        the decoded string
        Throws:
        java.nio.charset.CharacterCodingException

      • string

        public static java.lang.String string​(java.nio.ByteBuffer buffer,
                                      java.nio.charset.Charset charset)
                               throws java.nio.charset.CharacterCodingException
        Decode a String representation.
        Parameters:
        buffer - a byte buffer holding the string representation
        charset - the String encoding charset
        Returns:
        the decoded string
        Throws:
        java.nio.charset.CharacterCodingException

      • getArray

        public static byte[] getArray​(java.nio.ByteBuffer buffer)
        You should almost never use this. Instead, use the write* methods to avoid copies.

      • getArray

        public static byte[] getArray​(java.nio.ByteBuffer buffer,
                              int position,
                              int length)
        You should almost never use this. Instead, use the write* methods to avoid copies.

      • lastIndexOf

        public static int lastIndexOf​(java.nio.ByteBuffer buffer,
                              byte valueToFind,
                              int startIndex)
        ByteBuffer adaptation of org.apache.commons.lang3.ArrayUtils.lastIndexOf method
        Parameters:
        buffer - the array to traverse for looking for the object, may be null
        valueToFind - the value to find
        startIndex - the start index (i.e. BB position) to travers backwards from
        Returns:
        the last index (i.e. BB position) of the value within the array [between buffer.position() and buffer.limit()]; -1 if not found.

      • bytes

        public static java.nio.ByteBuffer bytes​(java.lang.String s)
        Encode a String in a ByteBuffer using UTF_8.
        Parameters:
        s - the string to encode
        Returns:
        the encoded string

      • bytes

        public static java.nio.ByteBuffer bytes​(java.lang.String s,
                                        java.nio.charset.Charset charset)
        Encode a String in a ByteBuffer using the provided charset.
        Parameters:
        s - the string to encode
        charset - the String encoding charset to use
        Returns:
        the encoded string

      • clone

        public static java.nio.ByteBuffer clone​(java.nio.ByteBuffer buffer)
        Returns:
        a new copy of the data in @param buffer USUALLY YOU SHOULD USE ByteBuffer.duplicate() INSTEAD, which creates a new Buffer (so you can mutate its position without affecting the original) without copying the underlying array.

      • copyBytes

        public static void copyBytes​(java.nio.ByteBuffer src,
                             int srcPos,
                             byte[] dst,
                             int dstPos,
                             int length)
        Transfer bytes from a ByteBuffer to byte array.
        Parameters:
        src - the source ByteBuffer
        srcPos - starting position in the source ByteBuffer
        dst - the destination byte array
        dstPos - starting position in the destination byte array
        length - the number of bytes to copy

      • copyBytes

        public static void copyBytes​(java.nio.ByteBuffer src,
                             int srcPos,
                             java.nio.ByteBuffer dst,
                             int dstPos,
                             int length)
        Transfer bytes from one ByteBuffer to another. This function acts as System.arrayCopy() but for ByteBuffers, and operates safely on direct memory.
        Parameters:
        src - the source ByteBuffer
        srcPos - starting position in the source ByteBuffer
        dst - the destination ByteBuffer
        dstPos - starting position in the destination ByteBuffer
        length - the number of bytes to copy

      • put

        public static int put​(java.nio.ByteBuffer src,
                      java.nio.ByteBuffer trg)

      • writeZeroes

        public static void writeZeroes​(java.nio.ByteBuffer dest,
                               int count)

      • writeWithLength

        public static void writeWithLength​(java.nio.ByteBuffer bytes,
                                   DataOutputPlus out)
                            throws java.io.IOException
        Throws:
        java.io.IOException

      • writeWithVIntLength

        public static void writeWithVIntLength​(java.nio.ByteBuffer bytes,
                                       DataOutputPlus out)
                                throws java.io.IOException
        Throws:
        java.io.IOException

      • writeWithShortLength

        public static void writeWithShortLength​(java.nio.ByteBuffer buffer,
                                        DataOutputPlus out)
                                 throws java.io.IOException
        Throws:
        java.io.IOException

      • readWithLength

        public static java.nio.ByteBuffer readWithLength​(java.io.DataInput in)
                                          throws java.io.IOException
        Throws:
        java.io.IOException

      • readWithVIntLength

        public static java.nio.ByteBuffer readWithVIntLength​(DataInputPlus in)
                                              throws java.io.IOException
        Throws:
        java.io.IOException

      • serializedSizeWithLength

        public static int serializedSizeWithLength​(java.nio.ByteBuffer buffer)

      • serializedSizeWithVIntLength

        public static int serializedSizeWithVIntLength​(java.nio.ByteBuffer buffer)

      • skipWithVIntLength

        public static void skipWithVIntLength​(DataInputPlus in)
                               throws java.io.IOException
        Throws:
        java.io.IOException

      • readShortLength

        public static int readShortLength​(java.io.DataInput in)
                           throws java.io.IOException
        Throws:
        java.io.IOException

      • readWithShortLength

        public static java.nio.ByteBuffer readWithShortLength​(java.io.DataInput in)
                                               throws java.io.IOException
        Parameters:
        in - data input
        Returns:
        An unsigned short in an integer.
        Throws:
        java.io.IOException - if an I/O error occurs.

      • serializedSizeWithShortLength

        public static int serializedSizeWithShortLength​(java.nio.ByteBuffer buffer)

      • skipShortLength

        public static void skipShortLength​(DataInputPlus in)
                            throws java.io.IOException
        Parameters:
        in - data input
        Throws:
        java.io.IOException - if an I/O error occurs.

      • read

        public static java.nio.ByteBuffer read​(java.io.DataInput in,
                                       int length)
                                throws java.io.IOException
        Throws:
        java.io.IOException

      • readBytes

        public static byte[] readBytes​(java.io.DataInput in,
                               int length)
                        throws java.io.IOException
        Throws:
        java.io.IOException

      • readBytesWithLength

        public static byte[] readBytesWithLength​(java.io.DataInput in)
                                  throws java.io.IOException
        Throws:
        java.io.IOException

      • toInt

        public static int toInt​(java.nio.ByteBuffer bytes)
        Convert a byte buffer to an integer. Does not change the byte buffer position.
        Parameters:
        bytes - byte buffer to convert to integer
        Returns:
        int representation of the byte buffer

      • toShort

        public static short toShort​(java.nio.ByteBuffer bytes)
        Convert a byte buffer to a short. Does not change the byte buffer position.
        Parameters:
        bytes - byte buffer to convert to short
        Returns:
        short representation of the byte buffer

      • toByte

        public static byte toByte​(java.nio.ByteBuffer bytes)
        Convert a byte buffer to a short. Does not change the byte buffer position.
        Parameters:
        bytes - byte buffer to convert to byte
        Returns:
        byte representation of the byte buffer

      • toLong

        public static long toLong​(java.nio.ByteBuffer bytes)

      • toFloat

        public static float toFloat​(java.nio.ByteBuffer bytes)

      • getFloat

        public static float getFloat​(java.nio.ByteBuffer bytes,
                             int offset)

      • toDouble

        public static double toDouble​(java.nio.ByteBuffer bytes)

      • objectToBytes

        public static java.nio.ByteBuffer objectToBytes​(java.lang.Object obj)

      • bytes

        public static java.nio.ByteBuffer bytes​(byte b)

      • bytes

        public static java.nio.ByteBuffer bytes​(short s)

      • bytes

        public static java.nio.ByteBuffer bytes​(int i)

      • bytes

        public static java.nio.ByteBuffer bytes​(long n)

      • bytes

        public static java.nio.ByteBuffer bytes​(float f)

      • bytes

        public static java.nio.ByteBuffer bytes​(double d)

      • inputStream

        public static java.io.InputStream inputStream​(java.nio.ByteBuffer bytes)

      • bytesToHex

        public static java.lang.String bytesToHex​(java.nio.ByteBuffer bytes)

      • hexToBytes

        public static java.nio.ByteBuffer hexToBytes​(java.lang.String str)

      • compareSubArrays

        public static int compareSubArrays​(java.nio.ByteBuffer bytes1,
                                   int offset1,
                                   java.nio.ByteBuffer bytes2,
                                   int offset2,
                                   int length)
        Compare two ByteBuffer at specified offsets for length. Compares the non equal bytes as unsigned.
        Parameters:
        bytes1 - First byte buffer to compare.
        offset1 - Position to start the comparison at in the first array.
        bytes2 - Second byte buffer to compare.
        offset2 - Position to start the comparison at in the second array.
        length - How many bytes to compare?
        Returns:
        -1 if byte1 is less than byte2, 1 if byte2 is less than byte1 or 0 if equal.

      • bytes

        public static java.nio.ByteBuffer bytes​(java.net.InetAddress address)

      • bytes

        public static java.nio.ByteBuffer bytes​(java.util.UUID uuid)

      • bytes

        public static java.nio.ByteBuffer bytes​(TimeUUID uuid)

      • isPrefix

        public static boolean isPrefix​(java.nio.ByteBuffer prefix,
                               java.nio.ByteBuffer value)

      • canMinimize

        public static boolean canMinimize​(java.nio.ByteBuffer buf)

      • minimalBufferFor

        public static java.nio.ByteBuffer minimalBufferFor​(java.nio.ByteBuffer buf)
        trims size of bytebuffer to exactly number of bytes in it, to do not hold too much memory

      • minimizeBuffers

        public static java.nio.ByteBuffer[] minimizeBuffers​(java.nio.ByteBuffer[] src)

      • canMinimize

        public static boolean canMinimize​(java.nio.ByteBuffer[] src)

      • getUnsignedShort

        public static int getUnsignedShort​(java.nio.ByteBuffer bb,
                                   int position)

      • getShortLength

        public static int getShortLength​(java.nio.ByteBuffer bb,
                                 int position)

      • readShortLength

        public static int readShortLength​(java.nio.ByteBuffer bb)

      • writeShortLength

        public static void writeShortLength​(java.nio.ByteBuffer bb,
                                    int length)

      • readBytes

        public static java.nio.ByteBuffer readBytes​(java.nio.ByteBuffer bb,
                                            int length)

      • readBytesWithShortLength

        public static java.nio.ByteBuffer readBytesWithShortLength​(java.nio.ByteBuffer bb)

      • ensureCapacity

        public static java.nio.ByteBuffer ensureCapacity​(java.nio.ByteBuffer buf,
                                                 int outputLength,
                                                 boolean allowBufferResize)
        Ensure buf is large enough for outputLength. If not, it is cleaned up and a new buffer is allocated; else; buffer has it's position/limit set appropriately.
        Parameters:
        buf - buffer to test the size of; may be null, in which case, a new buffer is allocated.
        outputLength - the minimum target size of the buffer
        allowBufferResize - true if resizing (reallocating) the buffer is allowed
        Returns:
        buf if it was large enough, else a newly allocated buffer.

      • ensureCapacity

        public static java.nio.ByteBuffer ensureCapacity​(java.nio.ByteBuffer buf,
                                                 int outputLength,
                                                 boolean allowBufferResize,
                                                 BufferType bufferType)
        Ensure buf is large enough for outputLength. If not, it is cleaned up and a new buffer is allocated; else; buffer has it's position/limit set appropriately.
        Parameters:
        buf - buffer to test the size of; may be null, in which case, a new buffer is allocated.
        outputLength - the minimum target size of the buffer
        allowBufferResize - true if resizing (reallocating) the buffer is allowed
        bufferType - on- or off- heap byte buffer
        Returns:
        buf if it was large enough, else a newly allocated buffer.

      • contains

        public static boolean contains​(java.nio.ByteBuffer buffer,
                               java.nio.ByteBuffer subBuffer)
        Check is the given buffer contains a given sub-buffer.
        Parameters:
        buffer - The buffer to search for sequence of bytes in.
        subBuffer - The buffer to match.
        Returns:
        true if buffer contains sub-buffer, false otherwise.

      • startsWith

        public static boolean startsWith​(java.nio.ByteBuffer src,
                                 java.nio.ByteBuffer prefix)

      • endsWith

        public static boolean endsWith​(java.nio.ByteBuffer src,
                               java.nio.ByteBuffer suffix)

      • equalsWithShortLength

        public static boolean equalsWithShortLength​(java.io.DataInput in,
                                            java.nio.ByteBuffer toMatch)
                                     throws java.io.IOException
        Returns true if the buffer at the current position in the input matches given buffer. If true, the input is positioned at the end of the consumed buffer. If false, the position of the input is undefined.

        The matched buffer is unchanged

        Throws:
        java.io.IOException

      • readFully

        public static void readFully​(java.nio.channels.FileChannel channel,
                             java.nio.ByteBuffer dst,
                             long position)
                      throws java.io.IOException
        Throws:
        java.io.IOException