Package com.itextpdf.io.source

Class MappedChannelRandomAccessSource

  • All Implemented Interfaces:
    IRandomAccessSource
    class MappedChannelRandomAccessSource
extends java.lang.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 java.nio.channels.FileChannel channel
      The underlying channel
      private long length
      The number of bytes this source maps to
      private 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​(java.nio.channels.FileChannel channel, long offset, long length)
      Create a new source based on the channel.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      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
      java.lang.String toString()  

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • channel

        private final java.nio.channels.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

    • Constructor Detail

      • MappedChannelRandomAccessSource

        public MappedChannelRandomAccessSource​(java.nio.channels.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 Detail

      • open

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

      • get

        public int get​(long position)
        throws java.io.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:
        java.io.IOException - in case of any reading error.

      • get

        public int get​(long position,
               byte[] bytes,
               int off,
               int len)
        throws java.io.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:
        java.io.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 java.io.IOException
        Closes this source. The underlying data structure or source (if any) will also be closed
        Specified by:
        close in interface IRandomAccessSource
        Throws:
        java.io.IOException - in case of any reading error.

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object