Package org.apache.derby.impl.store.raw.data

Class RememberBytesInputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    public class RememberBytesInputStream
extends java.io.FilterInputStream
    A FilterInputStream that remembers read or skipped bytes.

    In record mode this stream remembers all the bytes a caller reads or skips. After reading some bytes this returns a 'replay' stream to re-read them.

    A caller may call getReplaySteam to get a stream to re-read the the remembered bytes. Any number of calls to getReplayStream are supported.

    The clear function causes this stream to forget the remembered bytes and re-enter record mode.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      (package private) ByteHolder bh  
      (package private) boolean recording  
      (package private) boolean streamClosed  

      • Fields inherited from class java.io.FilterInputStream

        in

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int available()
      Return the number of bytes remains in the byteHolder for reading, without setting the write/read mode.
      void clear()
      Clear all the remembered bytes.
      long fillBuf​(int len)
      read len bytes from the input stream, and store it in the byte holder.
      ByteHolder getByteHolder()
      Get the byteHolder.
      java.io.InputStream getReplayStream()
      Get an input stream for re-reading the remembered bytes.
      int numBytesSaved()
      Return the number of bytes that have been saved to this byte holder.
      int putBuf​(java.io.OutputStream out, int len)
      read len bytes from the byte holder, and write it to the output stream.
      int read()  
      int read​(byte[] b, int off, int len)  
      boolean recording()
      Return true iff this RememberBytesInputStream is in recording mode.
      void setInput​(java.io.InputStream in)
      Set the InputStream from which this reads.
      int shiftToFront()
      remove the remaining bytes in the byteHolder to the beginning set the position to start recording just after these bytes.
      long skip​(long count)  
      java.lang.String toString()  

      • Methods inherited from class java.io.FilterInputStream

        close, mark, markSupported, read, reset

      • Methods inherited from class java.io.InputStream

        nullInputStream, readAllBytes, readNBytes, readNBytes, transferTo

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • recording

        boolean recording

      • streamClosed

        boolean streamClosed

    • Constructor Detail

      • RememberBytesInputStream

        public RememberBytesInputStream​(java.io.InputStream in,
                                ByteHolder bh)
        Construct a RememberBytesInputStream.
        Parameters:
        bh - for storing the remembered bytes. (must be in writing mode.

    • Method Detail

      • read

        public int read()
         throws java.io.IOException
        Overrides:
        read in class java.io.FilterInputStream
        Throws:
        java.io.IOException - thrown on an io error spooling rememberd bytes to backing storage.
        See Also:
        InputStream.read()

      • read

        public int read​(byte[] b,
                int off,
                int len)
         throws java.io.IOException
        Overrides:
        read in class java.io.FilterInputStream
        Throws:
        java.io.IOException - thrown on an io error spooling rememberd bytes to backing storage.
        See Also:
        InputStream.read()

      • fillBuf

        public long fillBuf​(int len)
             throws java.io.IOException
        read len bytes from the input stream, and store it in the byte holder. Note, fillBuf does not return negative values, if there are no bytes to store in the byteholder, it will return 0
        Throws:
        java.io.IOException - thrown on an io error spooling rememberd bytes to backing storage.

      • putBuf

        public int putBuf​(java.io.OutputStream out,
                  int len)
           throws java.io.IOException
        read len bytes from the byte holder, and write it to the output stream.
        Throws:
        java.io.IOException - thrown on an io error spooling rememberd bytes to backing storage.

      • skip

        public long skip​(long count)
          throws java.io.IOException
        Overrides:
        skip in class java.io.FilterInputStream
        Throws:
        java.io.IOException - thrown on an io error spooling rememberd bytes to backing storage.
        See Also:
        InputStream.skip(long)

      • getReplayStream

        public java.io.InputStream getReplayStream()
                                    throws java.io.IOException
        Get an input stream for re-reading the remembered bytes.
        Throws:
        java.io.IOException

      • getByteHolder

        public ByteHolder getByteHolder()
                         throws java.io.IOException
        Get the byteHolder.
        Throws:
        java.io.IOException

      • clear

        public void clear()
           throws java.io.IOException
        Clear all the remembered bytes. This stream will remember any bytes read after this call.
        Throws:
        java.io.IOException - thrown on an io error clearing backing storage.

      • setInput

        public void setInput​(java.io.InputStream in)
        Set the InputStream from which this reads.

        Please note this does not clear remembered bytes.

      • recording

        public boolean recording()
        Return true iff this RememberBytesInputStream is in recording mode.

      • available

        public int available()
              throws java.io.IOException
        Return the number of bytes remains in the byteHolder for reading, without setting the write/read mode.
        Overrides:
        available in class java.io.FilterInputStream
        Throws:
        java.io.IOException

      • numBytesSaved

        public int numBytesSaved()
                  throws java.io.IOException
        Return the number of bytes that have been saved to this byte holder. This result is different from available() as it is unaffected by the current read position on the ByteHolder.
        Throws:
        java.io.IOException

      • shiftToFront

        public int shiftToFront()
                 throws java.io.IOException
        remove the remaining bytes in the byteHolder to the beginning set the position to start recording just after these bytes. returns how many bytes was transfered to the beginning.
        Throws:
        java.io.IOException

      • toString

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