Class CustomBuffer<SELF extends CustomBuffer<SELF>>

  • All Implemented Interfaces:
    Pointer
    Direct Known Subclasses:
    PointerBuffer, StructBuffer

    public abstract class CustomBuffer<SELF extends CustomBuffer<SELF>>
    extends java.lang.Object
    implements Pointer
    Base class of custom buffers with an API that mirrors java.nio for convenience.
    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      long address()
      Returns the memory address at the current buffer position.
      long address​(int position)
      Returns the memory address at the specified buffer position.
      long address0()
      Returns the buffer's base address.
      int capacity()
      Returns this buffer's capacity.
      SELF clear()
      Clears this buffer.
      SELF compact()
      Compacts this buffer  (optional operation).
      SELF duplicate()
      Creates a new buffer that shares this buffer's content.
      SELF flip()
      Flips this buffer.
      void free()
      Frees the buffer allocation.
      boolean hasRemaining()
      Tells whether there are any elements between the current position and the limit.
      int limit()
      Returns this buffer's limit.
      SELF limit​(int limit)
      Sets this buffer's limit.
      SELF mark()
      Sets this buffer's mark at its position.
      int position()
      Returns this buffer's position.
      SELF position​(int position)
      Sets this buffer's position.
      SELF put​(SELF src)
      Relative bulk put method  (optional operation).
      int remaining()
      Returns the number of elements between the current position and the limit.
      SELF reset()
      Resets this buffer's position to the previously-marked position.
      SELF rewind()
      Rewinds this buffer.
      abstract int sizeof()
      Returns the sizeof a single element in the buffer.
      SELF slice()
      Creates a new buffer whose content is a shared subsequence of this buffer's content.
      SELF slice​(int offset, int capacity)
      Returns a slice of this buffer between (buffer.position() + offset) and (buffer.position() + offset + capacity).
      java.lang.String toString()
      Returns a string summarizing the state of this buffer.
      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Method Detail

      • sizeof

        public abstract int sizeof()
        Returns the sizeof a single element in the buffer.
      • address0

        public long address0()
        Returns the buffer's base address. [INTERNAL USE ONLY]
      • address

        public long address()
        Returns the memory address at the current buffer position.
        Specified by:
        address in interface Pointer
        Returns:
        the pointer address
      • address

        public long address​(int position)
        Returns the memory address at the specified buffer position.
      • free

        public void free()
        Frees the buffer allocation.

        This method should not be used if the memory backing this buffer is not owned by the buffer.

      • capacity

        public int capacity()
        Returns this buffer's capacity.
        Returns:
        the capacity of this buffer
      • position

        public int position()
        Returns this buffer's position.
        Returns:
        the position of this buffer
      • position

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

        public int limit()
        Returns this buffer's limit.
        Returns:
        the limit of this buffer
      • limit

        public SELF limit​(int limit)
        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:
        limit - the new limit value; must be non-negative and no larger than this buffer's capacity
        Returns:
        This buffer
        Throws:
        java.lang.IllegalArgumentException - If the preconditions on newLimit do not hold
      • mark

        public SELF mark()
        Sets this buffer's mark at its position.
        Returns:
        This buffer
      • reset

        public SELF reset()
        Resets this buffer's position to the previously-marked position.

        Invoking this method neither changes nor discards the mark's value.

        Returns:
        This buffer
        Throws:
        java.nio.InvalidMarkException - If the mark has not been set
      • clear

        public SELF 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
      • flip

        public SELF 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
      • rewind

        public SELF rewind()
        Rewinds this buffer. The position is set to zero and the mark is discarded.

        Invoke this method before a sequence of channel-write or get operations, assuming that the limit has already been set appropriately. For example:

         out.write(buf);    // Write remaining data
         buf.rewind();      // Rewind buffer
         buf.get(array);    // Copy data into array
        Returns:
        This buffer
      • remaining

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

        public boolean hasRemaining()
        Tells 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
      • slice

        public SELF slice()
        Creates a new buffer whose content is a shared subsequence of this buffer's content.

        The content of the new buffer will start at this buffer's current position. 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 position will be zero, its capacity and its limit will be the number of elements remaining in this buffer, and its mark will be undefined. The new buffer will be read-only if, and only if, this buffer is read-only.

        Returns:
        the new buffer
      • slice

        public SELF slice​(int offset,
                          int capacity)
        Returns a slice of this buffer between (buffer.position() + offset) and (buffer.position() + offset + capacity).

        The position and limit of this buffer are preserved after a call to this method.

        Parameters:
        offset - the slice offset, it must be ≤ this.remaining()
        capacity - the slice length, it must be ≤ this.capacity() - (this.position() + offset)
        Returns:
        the sliced buffer
      • duplicate

        public SELF duplicate()
        Creates a new 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 and position will be identical to those of this buffer.

        Returns:
        the new buffer
      • put

        public SELF put​(SELF src)
        Relative bulk put method  (optional operation).

        This method transfers the elements remaining in the specified source buffer into this buffer. If there are more elements remaining in the source buffer than in this buffer, that is, if src.remaining() &gt; remaining(), then no elements are transferred and a BufferOverflowException is thrown.

        Otherwise, this method copies n = src.remaining() elements from the specified buffer into this buffer, starting at each buffer's current position. The positions of both buffers are then incremented by n.

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

             while (src.hasRemaining())
                 dst.put(src.get()); 

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

        Parameters:
        src - the source buffer from which elements are to be read; must not be this buffer
        Returns:
        This buffer
        Throws:
        java.nio.BufferOverflowException - If there is insufficient space in this buffer for the remaining elements in the source buffer
        java.lang.IllegalArgumentException - If the source buffer is this buffer
        java.nio.ReadOnlyBufferException - If this buffer is read-only
      • compact

        public SELF compact()
        Compacts this buffer  (optional operation).

        The elements between the buffer's current position and its limit, if any, are copied to the beginning of the buffer. That is, the element at index p = position() is copied to index zero, the element at index p + 1 is copied to index one, and so forth until the element at index limit() - 1 is copied to index n = limit() - 1 -  p. The buffer's position is then set to n+1 and its limit is set to its capacity. The mark, if defined, is discarded.

        The buffer's position is set to the number of elements copied, rather than to zero, so that an invocation of this method can be followed immediately by an invocation of another relative put method.

        Returns:
        This buffer
        Throws:
        java.nio.ReadOnlyBufferException - If this buffer is read-only
      • toString

        public java.lang.String toString()
        Returns a string summarizing the state of this buffer.
        Overrides:
        toString in class java.lang.Object
        Returns:
        A summary string