Package org.bson

Interface ByteBuf

  • All Known Implementing Classes:
    ByteBufNIO
    public interface ByteBuf

    An interface wrapper around a java.nio.ByteBuffer which additionally is Closeable, so that pooled byte buffers know how.

    This interface is not frozen yet, and methods may be added in a minor release, so beware implementing this yourself.

    Since:
    3.0

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      byte[] array()
      Returns the byte array that backs this buffer (optional operation).
      ByteBuffer asNIO()
      Gets the underlying NIO ByteBuffer.
      ByteBuf asReadOnly()
      Creates a new, read-only byte buffer that shares this buffer's content.
      int capacity()
      Returns this buffer's capacity.
      ByteBuf clear()
      Clears this buffer.
      ByteBuf duplicate()
      Creates a new byte buffer that shares this buffer's content.
      ByteBuf flip()
      Flips this buffer.
      byte get()
      Relative get method.
      ByteBuf get​(byte[] bytes)
      Relative bulk get method.
      ByteBuf get​(byte[] bytes, int offset, int length)
      Relative bulk get method.
      byte get​(int index)
      Absolute get method.
      ByteBuf get​(int index, byte[] bytes)
      Absolute bulk get method.
      ByteBuf get​(int index, byte[] bytes, int offset, int length)
      Absolute bulk get method.
      double getDouble()
      Relative get method for reading a double value.
      double getDouble​(int index)
      Absolute get method for reading a double value.
      int getInt()
      Relative get method for reading an int value.
      int getInt​(int index)
      Absolute get method for reading an int value.
      long getLong()
      Relative get method for reading a long value.
      long getLong​(int index)
      Absolute get method for reading a long value.
      int getReferenceCount()
      Gets the current reference count, which starts at 0.
      boolean hasRemaining()
      States whether there are any elements between the current position and the limit.
      int limit()
      Returns this buffer's limit.
      ByteBuf limit​(int newLimit)
      Sets this buffer's limit.
      ByteBuf order​(ByteOrder byteOrder)
      Modifies this buffer's byte order.
      int position()
      Returns this buffer's position.
      ByteBuf position​(int newPosition)
      Sets this buffer's position.
      ByteBuf put​(byte b)
      Relative put method (optional operation).
      ByteBuf put​(byte[] src, int offset, int length)
      Relative bulk put method  (optional operation).
      ByteBuf put​(int index, byte b)
      Absolute put method (optional operation).
      void release()
      Release a reference to this object.
      int remaining()
      Returns the number of elements between the current position and the limit.
      ByteBuf retain()
      Retain an additional reference to this object.

    • Method Detail

      • capacity

        int capacity()
        Returns this buffer's capacity.
        Returns:
        The capacity of this buffer

      • put

        ByteBuf put​(int index,
            byte b)

        Absolute put method (optional operation).

        Writes the given byte into this buffer at the given index.

        Parameters:
        index - The index at which the byte will be written
        b - The byte value to be written
        Returns:
        This buffer
        Throws:
        IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit
        ReadOnlyBufferException - If this buffer is read-only

      • remaining

        int remaining()
        Returns the number of elements between the current position and the limit.
        Returns:
        The number of elements remaining in this buffer

      • put

        ByteBuf put​(byte[] src,
            int offset,
            int length)

        Relative bulk put method  (optional operation).

        This method transfers bytes into this buffer from the given source array. If there are more bytes to be copied from the array than remain in this buffer, that is, if length > remaining(), then no bytes are transferred and a BufferOverflowException is thrown.

        Otherwise, this method copies length bytes from the given array into this buffer, starting at the given offset in the array and at the current position of this buffer. The position of this buffer is then incremented by length.

        In other words, an invocation of this method of the form dst.put(src, off, len) has exactly the same effect as the loop

        
     for (int i = off; i < off + len; i++) {
         dst.put(a[i]);
     }

        except that it first checks that there is sufficient space in this buffer and it is potentially much more efficient.

        Parameters:
        src - The array from which bytes are to be read
        offset - The offset within the array of the first byte to be read; must be non-negative and no larger than array.length
        length - The number of bytes to be read from the given array; must be non-negative and no larger than array.length - offset
        Returns:
        This buffer
        Throws:
        BufferOverflowException - If there is insufficient space in this buffer
        IndexOutOfBoundsException - If the preconditions on the offset and length parameters do not hold
        ReadOnlyBufferException - If this buffer is read-only

      • hasRemaining

        boolean hasRemaining()
        States whether there are any elements between the current position and the limit.
        Returns:
        true if, and only if, there is at least one element remaining in this buffer

      • put

        ByteBuf put​(byte b)

        Relative put method (optional operation).

        Writes the given byte into this buffer at the current position, and then increments the position.

        Parameters:
        b - The byte to be written
        Returns:
        This buffer
        Throws:
        BufferOverflowException - If this buffer's current position is not smaller than its limit
        ReadOnlyBufferException - If this buffer is read-only

      • flip

        ByteBuf flip()

        Flips this buffer. The limit is set to the current position and then the position is set to zero. If the mark is defined then it is discarded.

        After a sequence of channel-read or put operations, invoke this method to prepare for a sequence of channel-write or relative get operations. For example: 

         buf.put(magic);    // Prepend header
 in.read(buf);      // Read data into rest of buffer
 buf.flip();        // Flip buffer
 out.write(buf);    // Write header + data to channel

        This method is often used in conjunction with the compact method when transferring data from one place to another.

        Returns:
        This buffer

      • array

        byte[] array()

        Returns the byte array that backs this buffer (optional operation).

        Modifications to this buffer's content will cause the returned array's content to be modified, and vice versa.

        Returns:
        The array that backs this buffer
        Throws:
        ReadOnlyBufferException - If this buffer is backed by an array but is read-only
        UnsupportedOperationException - If this buffer is not backed by an accessible array

      • limit

        int limit()
        Returns this buffer's limit.
        Returns:
        The limit of this buffer

      • position

        ByteBuf position​(int newPosition)
        Sets this buffer's position. If the mark is defined and larger than the new position then it is discarded.
        Parameters:
        newPosition - The new position value; must be non-negative and no larger than the current limit
        Returns:
        This buffer
        Throws:
        IllegalArgumentException - If the preconditions on newPosition do not hold

      • clear

        ByteBuf clear()

        Clears this buffer. The position is set to zero, the limit is set to the capacity, and the mark is discarded.

        Invoke this method before using a sequence of channel-read or put operations to fill this buffer. For example: 

         buf.clear();     // Prepare buffer for reading
 in.read(buf);    // Read data

        This method does not actually erase the data in the buffer, but it is named as if it did because it will most often be used in situations in which that might as well be the case.

        Returns:
        This buffer

      • get

        byte get()
        Relative get method. Reads the byte at this buffer's current position, and then increments the position.
        Returns:
        The byte at the buffer's current position
        Throws:
        BufferUnderflowException - If the buffer's current position is not smaller than its limit

      • get

        byte get​(int index)
        Absolute get method. Reads the byte at the given index.
        Parameters:
        index - The index from which the byte will be read
        Returns:
        The byte at the given index
        Throws:
        IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit

      • get

        ByteBuf get​(byte[] bytes)

        Relative bulk get method.

        This method transfers bytes from this buffer into the given destination array. An invocation of this method of the form src.get(a) behaves in exactly the same way as the invocation:

         src.get(a, 0, a.length)
        Parameters:
        bytes - the destination byte array
        Returns:
        This buffer
        Throws:
        BufferUnderflowException - If there are fewer than length bytes remaining in this buffer

      • get

        ByteBuf get​(int index,
            byte[] bytes)

        Absolute bulk get method.

        This method transfers bytes from this buffer into the given destination array. An invocation of this method of the form src.get(a) behaves in exactly the same way as the invocation:

         src.get(index, a, 0, a.length)
        Parameters:
        index - The index from which the bytes will be read
        bytes - the destination byte array
        Returns:
        This buffer
        Throws:
        BufferUnderflowException - If there are fewer than length bytes remaining in this buffer

      • get

        ByteBuf get​(byte[] bytes,
            int offset,
            int length)
        Relative bulk get method.

        This method transfers bytes from this buffer into the given destination array. If there are fewer bytes remaining in the buffer than are required to satisfy the request, that is, if length > remaining(), then no bytes are transferred and a BufferUnderflowException is thrown.

        Otherwise, this method copies length bytes from this buffer into the given array, starting at the current position of this buffer and at the given offset in the array. The position of this buffer is then incremented by length.

        In other words, an invocation of this method of the form src.get(dst, off, len) has exactly the same effect as the loop 

         
     for (int i = off; i < off + len; i++)
         dst[i] = src.get();
        except that it first checks that there are sufficient bytes in this buffer and it is potentially much more efficient.
        Parameters:
        bytes - The array into which bytes are to be written
        offset - The offset within the array of the first byte to be written; must be non-negative and no larger than dst.length
        length - The maximum number of bytes to be written to the given array; must be non-negative and no larger than dst.length - offset
        Returns:
        This buffer
        Throws:
        BufferUnderflowException - If there are fewer than length bytes remaining in this buffer
        IndexOutOfBoundsException - If the preconditions on the offset and length parameters do not hold

      • get

        ByteBuf get​(int index,
            byte[] bytes,
            int offset,
            int length)
        Absolute bulk get method.

        This method transfers bytes from this buffer into the given destination array. If there are fewer bytes remaining in the buffer than are required to satisfy the request, that is, if length &gt; remaining, then no bytes are transferred and a BufferUnderflowException is thrown.

        Otherwise, this method copies length bytes from this buffer into the given array, starting at the given index buffer and at the given offset in the array.

        In other words, an invocation of this method of the form src.get(dst, off, len) has exactly the same effect as the loop 

         
     for (int i = off; i < off + len; i++)
         dst[i] = src.get(i);
        except that it first checks that there are sufficient bytes in this buffer and it is potentially much more efficient.
        Parameters:
        index - The index from which the bytes will be read
        bytes - The array into which bytes are to be written
        offset - The offset within the array of the first byte to be written; must be non-negative and no larger than dst.length
        length - The maximum number of bytes to be written to the given array; must be non-negative and no larger than dst.length - offset
        Returns:
        This buffer
        Throws:
        BufferUnderflowException - If there are fewer than length bytes remaining in this buffer
        IndexOutOfBoundsException - If the preconditions on the offset and length parameters do not hold

      • getLong

        long getLong()

        Relative get method for reading a long value.

        Reads the next eight bytes at this buffer's current position, composing them into a long value according to the current byte order, and then increments the position by eight.

        Returns:
        The long value at the buffer's current position
        Throws:
        BufferUnderflowException - If there are fewer than eight bytes remaining in this buffer

      • getLong

        long getLong​(int index)
        Absolute get method for reading a long value.

        Reads eight bytes at the given index, composing them into a long value according to the current byte order.

        Parameters:
        index - The index from which the bytes will be read
        Returns:
        The long value at the given index
        Throws:
        IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus seven

      • getDouble

        double getDouble()

        Relative get method for reading a double value.

        Reads the next eight bytes at this buffer's current position, composing them into a double value according to the current byte order, and then increments the position by eight.

        Returns:
        The double value at the buffer's current position
        Throws:
        BufferUnderflowException - If there are fewer than eight bytes remaining in this buffer

      • getDouble

        double getDouble​(int index)
        Absolute get method for reading a double value.

        Reads eight bytes at the given index, composing them into a double value according to the current byte order.

        Parameters:
        index - The index from which the bytes will be read
        Returns:
        The double value at the given index
        Throws:
        IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus seven

      • getInt

        int getInt()

        Relative get method for reading an int value.

        Reads the next four bytes at this buffer's current position, composing them into an int value according to the current byte order, and then increments the position by four.

        Returns:
        The int value at the buffer's current position
        Throws:
        BufferUnderflowException - If there are fewer than four bytes remaining in this buffer

      • getInt

        int getInt​(int index)
        Absolute get method for reading an int value.

        Reads four bytes at the given index, composing them into a int value according to the current byte order.

        Parameters:
        index - The index from which the bytes will be read
        Returns:
        The int value at the given index
        Throws:
        IndexOutOfBoundsException - If index is negative or not smaller than the buffer's limit, minus three

      • position

        int position()
        Returns this buffer's position.
        Returns:
        The position of this buffer

      • limit

        ByteBuf limit​(int newLimit)
        Sets this buffer's limit. If the position is larger than the new limit then it is set to the new limit. If the mark is defined and larger than the new limit then it is discarded.
        Parameters:
        newLimit - The new limit value; must be non-negative and no larger than this buffer's capacity
        Returns:
        This buffer
        Throws:
        IllegalArgumentException - If the preconditions on newLimit do not hold

      • asReadOnly

        ByteBuf asReadOnly()

        Creates a new, read-only byte buffer that shares this buffer's content.

        The content of the new buffer will be that of this buffer. Changes to this buffer's content will be visible in the new buffer; the new buffer itself, however, will be read-only and will not allow the shared content to be modified. The two buffers' position, limit, and mark values will be independent.

        The new buffer's capacity, limit, position, and mark values will be identical to those of this buffer.

        Returns:
        The new, read-only byte buffer

      • duplicate

        ByteBuf duplicate()

        Creates a new byte buffer that shares this buffer's content.

        The content of the new buffer will be that of this buffer. Changes to this buffer's content will be visible in the new buffer, and vice versa; the two buffers' position, limit, and mark values will be independent.

        The new buffer's capacity, limit, position, and mark values will be identical to those of this buffer. The new buffer will be direct if, and only if, this buffer is direct, and it will be read-only if, and only if, this buffer is read-only.

        Returns:
        The new byte buffer

      • asNIO

        ByteBuffer asNIO()
        Gets the underlying NIO ByteBuffer. Changes made directly to the returned buffer will be reflected in this instance, and vice versa, so be careful. This method should really only be used so that the underlying buffer can be passed directly to a socket channel.
        Returns:
        the underlying ByteBuffer

      • getReferenceCount

        int getReferenceCount()
        Gets the current reference count, which starts at 0.
        Returns:
        the current count, which must be greater than or equal to 0

      • retain

        ByteBuf retain()
        Retain an additional reference to this object. All retained references must be released, or there will be a leak.
        Returns:
        this

      • release

        void release()
        Release a reference to this object.
        Throws:
        IllegalStateException - if the reference count is already 0