Package com.tangosol.io

Class AbstractWriteBuffer

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected static int CHAR_BUF_MASK
      Bitmask used against a raw offset to determine the offset within the temporary character buffer.
      protected static int CHAR_BUF_SIZE
      Size of the temporary character buffer.
      protected char[] m_achBuf
      A lazily instantiated temp buffer used to avoid allocations from String.toCharArray() and repeated calls to String.charAt(int).
      static Binary NO_BINARY
      An empty Binary object.
      static byte[] NO_BYTES
      An empty byte array (by definition immutable).

    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      void clear()
      Set the length of the buffer as indicated by the WriteBuffer.length() method to zero.
      Object clone()
      Create a clone of this WriteBuffer object.
      protected void copyBufferInputPortion​(int ofDest, ReadBuffer.BufferInput inSrc, int cbSrc)
      Read a portion of the specified BufferInput and write it to the specified offset within this buffer.
      protected int copyBufferInputRemainder​(int ofDest, ReadBuffer.BufferInput inSrc, int cbMax)
      Read the remaining contents of the specified BufferInput and write it to the specified offset within this buffer.
      protected int copyStream​(int ofDest, InputStreaming stream, int cbMax)
      Store the remaining contents of the specified InputStreaming object at the specified offset within this buffer.
      WriteBuffer.BufferOutput getAppendingBufferOutput()
      Get a BufferOutput object to write data to this buffer.
      WriteBuffer.BufferOutput getBufferOutput()
      Get a BufferOutput object to write data to this buffer, starting at the beginning of the WriteBuffer.
      WriteBuffer.BufferOutput getBufferOutput​(int of)
      Get a BufferOutput object to write data to this buffer starting at a particular offset.
      abstract int getCapacity()
      Determine the number of bytes that the buffer can hold without resizing itself.
      int getMaximumCapacity()
      Determine the maximum number of bytes that the buffer can hold.
      ReadBuffer getReadBuffer()
      Get a ReadBuffer object that is a snapshot of this WriteBuffer's data.
      abstract ReadBuffer getUnsafeReadBuffer()
      Get a ReadBuffer object to read data from this buffer.
      WriteBuffer getWriteBuffer​(int of)
      Obtain a WriteBuffer starting at a particular offset within this WriteBuffer.
      WriteBuffer getWriteBuffer​(int of, int cb)
      Obtain a WriteBuffer for a portion of this WriteBuffer.
      abstract int length()
      Determine the length of the data that is in the buffer.
      protected void releaseBuffers()
      Release the internal buffers held by the WriteBuffer.
      void retain​(int of)
      Starting with the byte at offset of, retain the remainder of this WriteBuffer, such that the byte at offset of is shifted to offset 0, the byte at offset of + 1 is shifted to offset 1, and so on up to the byte at offset WriteBuffer.length() - 1, which is shifted to offset WriteBuffer.length() - of - 1.
      abstract void retain​(int of, int cb)
      Starting with the byte at offset of, retain cb bytes in this WriteBuffer, such that the byte at offset of is shifted to offset 0, the byte at offset of + 1 is shifted to offset 1, and so on up to the byte at offset of + cb - 1, which is shifted to offset cb - 1.
      protected byte[] tmpbuf()
      Get a small buffer for formating data to bytes.
      protected byte[] tmpbuf​(int cb)
      Get a buffer for formating data to bytes.
      Binary toBinary()
      Returns a new Binary object that holds the complete contents of this WriteBuffer.
      byte[] toByteArray()
      Returns a new byte array that holds the complete contents of this WriteBuffer.
      abstract void write​(int ofDest, byte b)
      Store the specified byte at the specified offset within the buffer.
      void write​(int ofDest, byte[] abSrc)
      Store the specified bytes at the specified offset within the buffer.
      abstract void write​(int ofDest, byte[] abSrc, int ofSrc, int cbSrc)
      Store the specified number of bytes from the specified location within the passed byte array at the specified offset within this buffer.
      void write​(int ofDest, InputStreaming stream)
      Store the remaining contents of the specified InputStreaming object at the specified offset within this buffer.
      void write​(int ofDest, InputStreaming stream, int cbSrc)
      Store the specified number of bytes from the specified InputStreaming object at the specified offset within this buffer.
      void write​(int ofDest, ReadBuffer bufSrc)
      Store the contents of the specified ReadBuffer at the specified offset within this buffer.
      void write​(int ofDest, ReadBuffer bufSrc, int ofSrc, int cbSrc)
      Store the specified portion of the contents of the specified ReadBuffer at the specified offset within this buffer.

    • Field Detail

      • NO_BYTES

        public static final byte[] NO_BYTES
        An empty byte array (by definition immutable).

      • NO_BINARY

        public static final Binary NO_BINARY
        An empty Binary object.

      • CHAR_BUF_SIZE

        protected static final int CHAR_BUF_SIZE
        Size of the temporary character buffer. Must be a power of 2.

        Size is: 256 characters (.25 KB).

        See Also:
        Constant Field Values

      • CHAR_BUF_MASK

        protected static final int CHAR_BUF_MASK
        Bitmask used against a raw offset to determine the offset within the temporary character buffer.
        See Also:
        Constant Field Values

    • Constructor Detail

      • AbstractWriteBuffer

        public AbstractWriteBuffer()

    • Method Detail

      • write

        public abstract void write​(int ofDest,
                           byte b)
        Store the specified byte at the specified offset within the buffer.

        For purposes of side-effects and potential exceptions, this method is functionally equivalent to the following code: 

        
 byte[] abSrc = new byte[1];
 abSrc[0] = b;
 write(ofDest, abSrc, 0, abSrc.length);
        Specified by:
        write in interface WriteBuffer
        Parameters:
        ofDest - the offset within this buffer to store the passed data
        b - the byte to store in this buffer

      • write

        public void write​(int ofDest,
                  byte[] abSrc)
        Store the specified bytes at the specified offset within the buffer.

        For purposes of side-effects and potential exceptions, this method is functionally equivalent to the following code: 

        
 write(ofDest, abSrc, 0, abSrc.length);
        Specified by:
        write in interface WriteBuffer
        Parameters:
        ofDest - the offset within this buffer to store the passed data
        abSrc - the array of bytes to store in this buffer

      • write

        public void write​(int ofDest,
                  ReadBuffer bufSrc)
        Store the contents of the specified ReadBuffer at the specified offset within this buffer.

        For purposes of side-effects and potential exceptions, this method is functionally equivalent to the following code: 

        
 byte[] abSrc = bufSrc.toByteArray();
 write(ofDest, abSrc, 0, abSrc.length);
        Specified by:
        write in interface WriteBuffer
        Parameters:
        ofDest - the offset within this buffer to store the passed data
        bufSrc - the array of bytes to store in this buffer

      • write

        public void write​(int ofDest,
                  ReadBuffer bufSrc,
                  int ofSrc,
                  int cbSrc)
        Store the specified portion of the contents of the specified ReadBuffer at the specified offset within this buffer.

        For purposes of side-effects and potential exceptions, this method is functionally equivalent to the following code: 

        
 byte[] abSrc = bufSrc.toByteArray(ofSrc, cbSrc);
 write(ofDest, abSrc, 0, abSrc.length);
        Specified by:
        write in interface WriteBuffer
        Parameters:
        ofDest - the offset within this buffer to store the passed data
        bufSrc - the array of bytes to store in this buffer
        ofSrc - the offset within the passed ReadBuffer to copy from
        cbSrc - the number of bytes to copy from the passed ReadBuffer

      • write

        public void write​(int ofDest,
                  InputStreaming stream)
           throws IOException
        Store the remaining contents of the specified InputStreaming object at the specified offset within this buffer.

        For purposes of side-effects and potential exceptions, this method is functionally similar to the following code: 

        
 ByteArrayOutputStream streamOut = new ByteArrayOutputStream();
 int b;
 while ((b = stream.read()) >= 0)
     {
     streamOut.write(b);
     }
 byte[] abSrc = streamOut.toByteArray();
 write(ofDest, abSrc, 0, abSrc.length);
        Specified by:
        write in interface WriteBuffer
        Parameters:
        ofDest - the offset within this buffer to store the passed data
        stream - the stream of bytes to read and store in this buffer
        Throws:
        IOException - if an IOException occurs reading from the passed stream

      • write

        public void write​(int ofDest,
                  InputStreaming stream,
                  int cbSrc)
           throws IOException
        Store the specified number of bytes from the specified InputStreaming object at the specified offset within this buffer.

        For purposes of side-effects and potential exceptions, this method is functionally similar to the following code: 

        
 DataInputStream streamData = new DataInputStream(
         new WrapperInputStream(stream));
 byte[] abSrc = new byte[cbSrc];
 streamData.readFully(abSrc);
 write(ofDest, abSrc, 0, abSrc.length);
        Specified by:
        write in interface WriteBuffer
        Parameters:
        ofDest - the offset within this buffer to store the passed data
        stream - the stream of bytes to read and store in this buffer
        cbSrc - the exact number of bytes to read from the stream and put in this buffer
        Throws:
        IOException - if an IOException occurs reading from the passed stream

      • length

        public abstract int length()
        Determine the length of the data that is in the buffer. This is the actual number of bytes of data that have been written to the buffer, not the capacity of the buffer.
        Specified by:
        length in interface WriteBuffer
        Returns:
        the number of bytes of data represented by this WriteBuffer

      • retain

        public void retain​(int of)
        Starting with the byte at offset of, retain the remainder of this WriteBuffer, such that the byte at offset of is shifted to offset 0, the byte at offset of + 1 is shifted to offset 1, and so on up to the byte at offset WriteBuffer.length() - 1, which is shifted to offset WriteBuffer.length() - of - 1. After this method, the length of of the buffer as indicated by the WriteBuffer.length() method will be equal to WriteBuffer.length() - of.

        This method is functionally equivalent to the following code: 

        
 retain(of, length() - of);
        Specified by:
        retain in interface WriteBuffer
        Parameters:
        of - the offset of the first byte within the WriteBuffer that will be retained

      • retain

        public abstract void retain​(int of,
                            int cb)
        Starting with the byte at offset of, retain cb bytes in this WriteBuffer, such that the byte at offset of is shifted to offset 0, the byte at offset of + 1 is shifted to offset 1, and so on up to the byte at offset of + cb - 1, which is shifted to offset cb - 1. After this method, the length of the buffer as indicated by the WriteBuffer.length() method will be equal to cb.

        Legal values for the offset of the first byte to retain of are (of >= 0 && of <= WriteBuffer.length()). Legal values for the number of bytes to retain cb are (cb >= 0 && cb <= WriteBuffer.length()), such that (of + cb <= WriteBuffer.length()).

        If cb is zero, then this method will have the same effect as clear. If of is zero, then this method will have the effect of truncating the data in the buffer, but no bytes will be shifted within the buffer.

        The effect on the capacity of the buffer is implementation-specific; some implementations are expected to retain the same capacity while others are expected to shrink accordingly.

        Specified by:
        retain in interface WriteBuffer
        Parameters:
        of - the offset of the first byte within the WriteBuffer that will be retained
        cb - the number of bytes to retain

      • clear

        public void clear()
        Set the length of the buffer as indicated by the WriteBuffer.length() method to zero.

        The effect on the capacity of the buffer is implementation-specific; some implementations are expected to retain the same capacity while others are expected to shrink accordingly.

        Specified by:
        clear in interface WriteBuffer

      • getCapacity

        public abstract int getCapacity()
        Determine the number of bytes that the buffer can hold without resizing itself. In other words, a WriteBuffer has getCapacity() - WriteBuffer.length() bytes that can be written to it without overflowing the current underlying buffer allocation. Since the buffer is an abstract concept, the actual mechanism for the underlying buffer is not known, but it could be a Java NIO buffer, or a byte array, etc.

        Note that if the maximum size returned by WriteBuffer.getMaximumCapacity() is greater than the current size returned by this method, then the WriteBuffer will automatically resize itself to allocate more space when the amount of data written to it passes the current size.

        Specified by:
        getCapacity in interface WriteBuffer
        Returns:
        the number of bytes of data that this WriteBuffer can hold without resizing its underlying buffer

      • getMaximumCapacity

        public int getMaximumCapacity()
        Determine the maximum number of bytes that the buffer can hold. If the maximum size is greater than the current size, then the buffer is expected to resize itself as necessary up to the maximum size in order to contain the data given to it.
        Specified by:
        getMaximumCapacity in interface WriteBuffer
        Returns:
        the maximum number of bytes of data that the WriteBuffer can hold

      • getWriteBuffer

        public WriteBuffer getWriteBuffer​(int of)
        Obtain a WriteBuffer starting at a particular offset within this WriteBuffer.

        This is functionally equivalent to: 

        
 return getWriteBuffer(of, getMaximumCapacity() - of);
        Specified by:
        getWriteBuffer in interface WriteBuffer
        Parameters:
        of - the beginning index, inclusive
        Returns:
        a WriteBuffer that represents a portion of this WriteBuffer

      • getWriteBuffer

        public WriteBuffer getWriteBuffer​(int of,
                                  int cb)
        Obtain a WriteBuffer for a portion of this WriteBuffer.

        Use of the resulting buffer will correspond to using this buffer directly but with the offset being passed to the buffer methods automatically having of added. As a result, the length of this buffer can be modified by writing to the new buffer; however, changes made directly to this buffer will not affect the length of the new buffer.

        Note that the resulting WriteBuffer is limited in the number of bytes that can be written to it; in other words, its WriteBuffer.getMaximumCapacity() must return the same value as was passed in cb.

        Specified by:
        getWriteBuffer in interface WriteBuffer
        Parameters:
        of - the offset of the first byte within this WriteBuffer to map to offset 0 of the new WriteBuffer
        cb - the number of bytes to cover in the resulting WriteBuffer
        Returns:
        a WriteBuffer that represents a portion of this WriteBuffer

      • getBufferOutput

        public WriteBuffer.BufferOutput getBufferOutput()
        Get a BufferOutput object to write data to this buffer, starting at the beginning of the WriteBuffer.

        This is functionally equivalent to: 

        
 return getBufferOutput(0);
        Specified by:
        getBufferOutput in interface WriteBuffer
        Returns:
        a BufferOutput that is writing to this buffer starting at offset zero

      • getBufferOutput

        public WriteBuffer.BufferOutput getBufferOutput​(int of)
        Get a BufferOutput object to write data to this buffer starting at a particular offset.

        Note that each call to this method will return a new BufferOutput object, with the possible exception being that a zero-length non-resizing WriteBuffer could always return the same instance (since it is not writable).

        This is functionally equivalent to: 

        
 BufferOutput bufout = getBufferOutput();
 bufout.setOffset(of);
 return bufout;
        Specified by:
        getBufferOutput in interface WriteBuffer
        Parameters:
        of - the offset of the first byte of this buffer that the BufferOutput will write to
        Returns:
        a BufferOutput that will write to this buffer

      • getAppendingBufferOutput

        public WriteBuffer.BufferOutput getAppendingBufferOutput()
        Get a BufferOutput object to write data to this buffer. The BufferOutput object returned by this method is set to append to the WriteBuffer, meaning that its offset is pre-set to the WriteBuffer.length() of this buffer.

        This is functionally equivalent to: 

        
 return getBufferOutput(length());
        Specified by:
        getAppendingBufferOutput in interface WriteBuffer
        Returns:
        a BufferOutput configured to append to this buffer

      • getReadBuffer

        public ReadBuffer getReadBuffer()
        Get a ReadBuffer object that is a snapshot of this WriteBuffer's data.

        This method is functionally equivalent to the following code: 

        
 ReadBuffer buf = getUnsafeReadBuffer();
 byte[] ab = buf.toByteArray();
 return new ByteArrayReadBuffer(ab);
        Specified by:
        getReadBuffer in interface WriteBuffer
        Returns:
        a ReadBuffer that reflects the point-in-time contents of this WriteBuffer

      • getUnsafeReadBuffer

        public abstract ReadBuffer getUnsafeReadBuffer()
        Get a ReadBuffer object to read data from this buffer. This method is not guaranteed to return a snapshot of this buffer's data, nor is it guaranteed to return a live view of this buffer, which means that subsequent changes to this WriteBuffer may or may not affect the contents and / or the length of the returned ReadBuffer.

        To get a snapshot, use the WriteBuffer.getReadBuffer() method.

        Specified by:
        getUnsafeReadBuffer in interface WriteBuffer
        Returns:
        a ReadBuffer that reflects the contents of this WriteBuffer but whose behavior is undefined if the WriteBuffer is modified

      • toByteArray

        public byte[] toByteArray()
        Returns a new byte array that holds the complete contents of this WriteBuffer.

        This method is functionally equivalent to the following code: 

        
 return getUnsafeReadBuffer().toByteArray();
        Specified by:
        toByteArray in interface WriteBuffer
        Returns:
        the contents of this WriteBuffer as a byte[]

      • toBinary

        public Binary toBinary()
        Returns a new Binary object that holds the complete contents of this WriteBuffer.

        This method is functionally equivalent to the following code: 

        
 return getUnsafeReadBuffer().toBinary();
        Specified by:
        toBinary in interface WriteBuffer
        Returns:
        the contents of this WriteBuffer as a Binary object

      • clone

        public Object clone()
        Create a clone of this WriteBuffer object. Changes to the clone will not affect the original, and vice-versa.
        Specified by:
        clone in interface WriteBuffer
        Overrides:
        clone in class Object
        Returns:
        a WriteBuffer object with the same contents as this WriteBuffer object

      • copyBufferInputPortion

        protected void copyBufferInputPortion​(int ofDest,
                                      ReadBuffer.BufferInput inSrc,
                                      int cbSrc)
                               throws IOException
        Read a portion of the specified BufferInput and write it to the specified offset within this buffer.
        Parameters:
        ofDest - the offset within this buffer to store the passed data
        inSrc - the BufferInput to read data from to copy to this buffer
        cbSrc - the exact number of bytes to read from the passed BufferInput
        Throws:
        IOException - if an IOException occurs reading from the passed stream

      • copyBufferInputRemainder

        protected int copyBufferInputRemainder​(int ofDest,
                                       ReadBuffer.BufferInput inSrc,
                                       int cbMax)
                                throws IOException
        Read the remaining contents of the specified BufferInput and write it to the specified offset within this buffer.
        Parameters:
        ofDest - the offset within this buffer to store the passed data
        inSrc - the BufferInput to read and store in this buffer
        cbMax - the maximum number of bytes to copy
        Returns:
        the actual number of bytes read from the BufferInput and written to this buffer
        Throws:
        IOException - if an IOException occurs reading from the passed stream or if the limit is reached without emptying the source stream

      • copyStream

        protected int copyStream​(int ofDest,
                         InputStreaming stream,
                         int cbMax)
                  throws IOException
        Store the remaining contents of the specified InputStreaming object at the specified offset within this buffer.
        Parameters:
        ofDest - the offset within this buffer to store the passed data
        stream - the stream of bytes to read and store in this buffer
        cbMax - the maximum number of bytes to copy
        Returns:
        the actual number of bytes read from the InputStreaming object and written to this buffer
        Throws:
        IOException - if an IOException occurs reading from the passed stream or if the limit is reached without emptying the source stream

      • tmpbuf

        protected byte[] tmpbuf()
        Get a small buffer for formating data to bytes.
        Returns:
        a byte array that is at least MIN_BUF bytes long

      • tmpbuf

        protected byte[] tmpbuf​(int cb)
        Get a buffer for formating data to bytes. Note that the resulting buffer may be shorter than the requested size.
        Parameters:
        cb - the requested size for the buffer
        Returns:
        a byte array that is at least cb bytes long, but not shorter than MIN_BUF and (regardless of the value of cb) not longer than MAX_BUF

      • releaseBuffers

        protected final void releaseBuffers()
        Release the internal buffers held by the WriteBuffer.