Package com.tangosol.io

Interface WriteBuffer

All Known Implementing Classes:
AbstractWriteBuffer, BinaryWriteBuffer, ByteArrayWriteBuffer, ByteBufferWriteBuffer, DelegatingWriteBuffer, MultiBufferWriteBuffer
public interface WriteBuffer
The WriteBuffer interface represents an in-memory block of binary data that is being accumulated (written to). It is analogous to the byte[] inside a Java ByteArrayOutputStream.
Author:
cp 2005.01.18 created, cp 2005.03.21 defining

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Interface
    Description
    static interface 
    WriteBuffer.BufferOutput
    The BufferOutput interface represents a DataOutputStream on top of a WriteBuffer.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
    Set the length of the buffer as indicated by the length() method to zero.
    Object
    clone()
    Create a clone of this WriteBuffer object.
    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.
    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.
    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.
    int
    length()
    Determine the length of the data that is in the buffer.
    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 length() - 1, which is shifted to offset length() - of - 1.
    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.
    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.
    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.
    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.

  • Method Details

    • write

      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);
      Parameters:
      ofDest - the offset within this buffer to store the passed data
      b - the byte to store in this buffer

    • write

      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);
      Parameters:
      ofDest - the offset within this buffer to store the passed data
      abSrc - the array of bytes to store in this buffer
      Throws:
      NullPointerException - if abSrc is null
      IndexOutOfBoundsException - if ofDest is negative, or if ofDest + abSrc.length is greater than getMaximumCapacity()

    • write

      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.

      As a result of this method, the buffer length as reported by the length() method will become Math.max(length(), ofDest + cbSrc).

      As a result of this method, the buffer capacity as reported by the getCapacity() method will not change if the new value returned by length() would not exceed the old value returned by getCapacity(); otherwise, the capacity will be increased such that getCapacity() >= length(). Regardless, it is always true that getCapacity() >= length() and getMaximumCapacity() >= getCapacity(). If the buffer capacity cannot be increased due to resource constraints, an undesignated Error or RuntimeException will be thrown, such as OutOfMemoryError.

      Parameters:
      ofDest - the offset within this buffer to store the passed data
      abSrc - the array containing the bytes to store in this buffer
      ofSrc - the offset within the passed byte array to copy from
      cbSrc - the number of bytes to copy from the passed byte array
      Throws:
      NullPointerException - if abSrc is null
      IndexOutOfBoundsException - if ofDest, ofSrc or cbSrc is negative, if ofSrc + cbSrc is greater than abSrc.length, or if ofDest + cbSrc is greater than getMaximumCapacity()

    • write

      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);
      Parameters:
      ofDest - the offset within this buffer to store the passed data
      bufSrc - the array of bytes to store in this buffer
      Throws:
      NullPointerException - if bufSrc is null
      IndexOutOfBoundsException - if ofDest is negative, or if ofDest + bufSrc.length() is greater than getMaximumCapacity()

    • write

      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);
      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
      Throws:
      NullPointerException - if bufSrc is null
      IndexOutOfBoundsException - if ofDest, ofSrc or cbSrc is negative, if ofSrc + cbSrc is greater than bufSrc.length(), or if ofDest + cbSrc is greater than getMaximumCapacity()

    • write

      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);
      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

      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);
      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

      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.
      Returns:
      the number of bytes of data represented by this WriteBuffer

    • retain

      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 length() - 1, which is shifted to offset length() - of - 1. After this method, the length of of the buffer as indicated by the length() method will be equal to length() - of.

      This method is functionally equivalent to the following code: 

      
 retain(of, length() - of);
      Parameters:
      of - the offset of the first byte within the WriteBuffer that will be retained
      Throws:
      IndexOutOfBoundsException - if of is negative or if of is greater than length()

    • retain

      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 length() method will be equal to cb.

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

      Parameters:
      of - the offset of the first byte within the WriteBuffer that will be retained
      cb - the number of bytes to retain
      Throws:
      IndexOutOfBoundsException - if of or cb is negative of if of + cb is greater than length()

    • clear

      void clear()
      Set the length of the buffer as indicated by the 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.

    • getCapacity

      int getCapacity()
      Determine the number of bytes that the buffer can hold without resizing itself. In other words, a WriteBuffer has getCapacity() - 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 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.

      Returns:
      the number of bytes of data that this WriteBuffer can hold without resizing its underlying buffer

    • getMaximumCapacity

      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.
      Returns:
      the maximum number of bytes of data that the WriteBuffer can hold

    • getWriteBuffer

      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);
      Parameters:
      of - the beginning index, inclusive
      Returns:
      a WriteBuffer that represents a portion of this WriteBuffer
      Throws:
      IndexOutOfBoundsException - if of is negative, or of is larger than the getMaximumCapacity() of this WriteBuffer object

    • getWriteBuffer

      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 getMaximumCapacity() must return the same value as was passed in cb.

      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
      Throws:
      IndexOutOfBoundsException - if of or cb is negative, or of + cb is larger than the getMaximumCapacity() of this WriteBuffer object

    • getBufferOutput

      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);
      Returns:
      a BufferOutput that is writing to this buffer starting at offset zero

    • getBufferOutput

      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;
      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

      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 length() of this buffer.

      This is functionally equivalent to: 

      
 return getBufferOutput(length());
      Returns:
      a BufferOutput configured to append to this buffer

    • getReadBuffer

      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);
      Returns:
      a ReadBuffer that reflects the point-in-time contents of this WriteBuffer

    • getUnsafeReadBuffer

      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 getReadBuffer() method.

      Returns:
      a ReadBuffer that reflects the contents of this WriteBuffer but whose behavior is undefined if the WriteBuffer is modified

    • toByteArray

      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();
      Returns:
      the contents of this WriteBuffer as a byte[]

    • toBinary

      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();
      Returns:
      the contents of this WriteBuffer as a Binary object

    • clone

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