Class MappedChannelRandomAccessSource

java.lang.Object
com.itextpdf.io.source.MappedChannelRandomAccessSource
All Implemented Interfaces:
IRandomAccessSource
class MappedChannelRandomAccessSource extends Object implements IRandomAccessSource
A RandomAccessSource that represents a memory mapped section of an underlying FileChannel. This source can be closed and will automatically re-open as needed. This class is an internal implementation detail of the FileChannelRandomAccessSource class and shouldn't be used by general iText users.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private final FileChannel
    channel
    The underlying channel
    private final long
    length
    The number of bytes this source maps to
    private final long
    offset
    The offset into the channel that this source maps to
    private ByteBufferRandomAccessSource
    source
    If the map is active, the actual map.

  • Constructor Summary

    Constructors
    Constructor
    Description
    MappedChannelRandomAccessSource(FileChannel channel, long offset, long length)
    Create a new source based on the channel.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    close()
    Closes this source.
    int
    get(long position)
    Gets a byte at the specified position
    int
    get(long position, byte[] bytes, int off, int len)
    Read an array of bytes of specified length from the specified position of source to the buffer applying the offset.
    long
    length()
    Gets the length of the source
    (package private) void
    open()
    Map the region of the channel
    String
    toString()
     

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Field Details

    • channel

      private final FileChannel channel
      The underlying channel

    • offset

      private final long offset
      The offset into the channel that this source maps to

    • length

      private final long length
      The number of bytes this source maps to

    • source

      private ByteBufferRandomAccessSource source
      If the map is active, the actual map. null other wise.

  • Constructor Details

    • MappedChannelRandomAccessSource

      public MappedChannelRandomAccessSource(FileChannel channel, long offset, long length)
      Create a new source based on the channel. Mapping will not occur until data is actually read.
      Parameters:
      channel - the underlying channel
      offset - the offset of the map
      length - the length of the map

  • Method Details

    • open

      void open() throws IOException
      Map the region of the channel
      Throws:
      IOException - if there is a problem with creating the map

    • get

      public int get(long position) throws IOException
      Gets a byte at the specified position
      Specified by:
      get in interface IRandomAccessSource
      Parameters:
      position - byte position
      Returns:
      the byte, or -1 if EOF is reached
      Throws:
      IOException - in case of any reading error.

    • get

      public int get(long position, byte[] bytes, int off, int len) throws IOException
      Read an array of bytes of specified length from the specified position of source to the buffer applying the offset. If the number of bytes requested cannot be read, all the possible bytes will be read to the buffer, and the number of actually read bytes will be returned.
      Specified by:
      get in interface IRandomAccessSource
      Parameters:
      position - the position in the RandomAccessSource to read from
      bytes - output buffer
      off - offset into the output buffer where results will be placed
      len - the number of bytes to read
      Returns:
      the number of bytes actually read, or -1 if the file is at EOF
      Throws:
      IOException - in case of any I/O error.

    • length

      public long length()
      Gets the length of the source
      Specified by:
      length in interface IRandomAccessSource
      Returns:
      the length of this source

    • close

      public void close() throws IOException
      Closes this source. The underlying data structure or source (if any) will also be closed
      Specified by:
      close in interface IRandomAccessSource
      Throws:
      IOException - in case of any reading error.

    • toString

      public String toString()
      Overrides:
      toString in class Object