Class FileBuffer.Segment

java.lang.Object
org.simpleframework.common.buffer.FileBuffer.Segment
All Implemented Interfaces:
Buffer
Enclosing class:
FileBuffer

private class FileBuffer.Segment extends Object implements Buffer
The Segment object is used to create a segment of the parent buffer. The segment will write to the parent however if can be read as a unique range of bytes starting with the first sequence of bytes appended to the segment. A segment can be used to create a collection of buffers backed by the same underlying file, as is require with multipart uploads.
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private boolean
    This determines if the segment is currently open or closed.
    private long
    This is the offset of the first byte within the sequence.
    private long
    This is the last byte within the segment for this segment.
    private Buffer
    This is the parent buffer that bytes are to be appended to.
    This is an internal segment created from this buffer object.
  • Constructor Summary

    Constructors
    Constructor
    Description
    Segment(Buffer parent, long first)
    Constructor for the Segment object.
  • Method Summary

    Modifier and Type
    Method
    Description
    This is used to allocate a segment within this buffer.
    append(byte[] array)
    This is used to append the specified data to the underlying file.
    append(byte[] array, int off, int size)
    This is used to append the specified data to the underlying file.
    void
    This will clear all data from the buffer.
    void
    This method is used to ensure the buffer can be closed.
    This method is used to acquire the buffered bytes as a string.
    encode(String charset)
    This method is used to acquire the buffered bytes as a string.
    long
    This is used to provide the number of bytes that have been written to the buffer.
    This method is used so that a buffer can be represented as a stream of bytes.
    long
    This determines how much space is left in the buffer.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • segment

      private FileBuffer.Segment segment
      This is an internal segment created from this buffer object.
    • parent

      private Buffer parent
      This is the parent buffer that bytes are to be appended to.
    • first

      private long first
      This is the offset of the first byte within the sequence.
    • last

      private long last
      This is the last byte within the segment for this segment.
    • closed

      private boolean closed
      This determines if the segment is currently open or closed.
  • Constructor Details

    • Segment

      public Segment(Buffer parent, long first)
      Constructor for the Segment object. This is used to create a segment from a parent buffer. A segment is a part of the parent buffer and appends its bytes to the parent. It can however be treated as an independent source of bytes.
      Parameters:
      parent - this is the parent buffer to be appended to
      first - this is the offset for the first byte in this
  • Method Details

    • allocate

      public Buffer allocate() throws IOException
      This is used to allocate a segment within this buffer. If the buffer is closed this will throw an exception, if however the buffer is still open then a segment is created which will write all appended data to this buffer. However it can be treated as an independent source of data.
      Specified by:
      allocate in interface Buffer
      Returns:
      this returns a buffer which is a segment of this
      Throws:
      IOException
    • append

      public Buffer append(byte[] array) throws IOException
      This is used to append the specified data to the underlying file. All bytes appended to the file can be consumed at a later stage by acquiring the InputStream from this buffer. Also if require the data can be encoded as a string object in a required character set.
      Specified by:
      append in interface Buffer
      Parameters:
      array - this is the array to write the the file
      Returns:
      this returns this buffer for further operations
      Throws:
      IOException
    • append

      public Buffer append(byte[] array, int off, int size) throws IOException
      This is used to append the specified data to the underlying file. All bytes appended to the file can be consumed at a later stage by acquiring the InputStream from this buffer. Also if require the data can be encoded as a string object in a required character set.
      Specified by:
      append in interface Buffer
      Parameters:
      array - this is the array to write the the file
      off - this is the offset within the array to write
      size - this is the number of bytes to be appended
      Returns:
      this returns this buffer for further operations
      Throws:
      IOException
    • encode

      public String encode() throws IOException
      This method is used to acquire the buffered bytes as a string. This is useful if the contents need to be manipulated as a string or transferred into another encoding. If the UTF-8 content encoding is not supported the platform default is used, however this is unlikely as UTF-8 should be supported.
      Specified by:
      encode in interface Buffer
      Returns:
      this returns a UTF-8 encoding of the buffer contents
      Throws:
      IOException
    • encode

      public String encode(String charset) throws IOException
      This method is used to acquire the buffered bytes as a string. This is useful if the contents need to be manipulated as a string or transferred into another encoding. This will convert the bytes using the specified character encoding format.
      Specified by:
      encode in interface Buffer
      Parameters:
      charset - this is the charset to encode the data with
      Returns:
      this returns the encoding of the buffer contents
      Throws:
      IOException
    • open

      public InputStream open() throws IOException
      This method is used so that a buffer can be represented as a stream of bytes. This provides a quick means to access the data that has been written to the buffer. It wraps the buffer within an input stream so that it can be read directly.
      Specified by:
      open in interface Buffer
      Returns:
      a stream that can be used to read the buffered bytes
      Throws:
      IOException
    • clear

      public void clear() throws IOException
      This will clear all data from the buffer. This simply sets the count to be zero, it will not clear the memory occupied by the instance as the internal buffer will remain. This allows the memory occupied to be reused as many times as is required.
      Specified by:
      clear in interface Buffer
      Throws:
      IOException
    • close

      public void close() throws IOException
      This method is used to ensure the buffer can be closed. Once the buffer is closed it is an immutable collection of bytes and can not longer be modified. This ensures that it can be passed by value without the risk of modification of the bytes.
      Specified by:
      close in interface Buffer
      Throws:
      IOException
    • space

      public long space()
      This determines how much space is left in the buffer. If there is no limit to the buffer size this will return the maximum long value. Typically this is the capacity minus the length.
      Returns:
      this is the space that is available within the buffer
    • length

      public long length()
      This is used to provide the number of bytes that have been written to the buffer. This increases as bytes are appended to the buffer. if the buffer is cleared this resets to zero.
      Specified by:
      length in interface Buffer
      Returns:
      this returns the number of bytes within the buffer