AutoPositioningStream (Apache Derby V10.14 Internals)

java.lang.Object
- java.io.InputStream
- - java.io.FilterInputStream
  - - org.apache.derby.impl.jdbc.BinaryToRawStream
    - - org.apache.derby.impl.jdbc.AutoPositioningStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable
```
final class AutoPositioningStream
extends BinaryToRawStream
```
This Stream is a wrapper for PositionedStoreStream to set the position correctly before performing any operation on it. All the read and skip methods ensure that the PositionedStoreStream is set to right position before actually performing these operations. PositionedStoreStream is accessed within synchronized block to ensure exclusive access to it. This class must be constructed while synchronizing on ConnectionChild.getConnectionSynchronization

Field Summary

Fields
Modifier and Type	Field	Description
`private ConnectionChild`	`conChild`	ConnectionChild to get synchronizion object
`private long`	`pos`
`private PositionedStoreStream`	`positionedStream`

Fields inherited from class java.io.FilterInputStream
in

Constructor Summary

Constructors
Constructor	Description
`AutoPositioningStream(ConnectionChild conChild, java.io.InputStream in, java.lang.Object parent)`	Constructs AutoPositioningStream object.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`read()`	Reads a single byte from the underlying stream.
`int`	`read(byte[] b)`	Reads a number of bytes from the underlying stream and stores them in the specified byte array.
`int`	`read(byte[] b, int off, int len)`	Reads a number of bytes from the underlying stream and stores them in the specified byte array at the specified offset.
`private void`	`setPosition()`	Checks if positionedStream's position was changed since last used, sets the position to right position if its changed.
`long`	`skip(long n)`	Skips up to the specified number of bytes from the underlying stream.

Methods inherited from class org.apache.derby.impl.jdbc.BinaryToRawStream
getLength

Methods inherited from class java.io.FilterInputStream
available, close, mark, markSupported, reset

Methods inherited from class java.io.InputStream
readAllBytes, readNBytes, transferTo

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - conChild
```
private final ConnectionChild conChild
```
    ConnectionChild to get synchronizion object
  - pos
```
private long pos
```
  - positionedStream
```
private final PositionedStoreStream positionedStream
```
- Constructor Detail
  - AutoPositioningStream
```
AutoPositioningStream(ConnectionChild conChild,
                      java.io.InputStream in,
                      java.lang.Object parent)
               throws java.io.IOException
```
    Constructs AutoPositioningStream object. This constructor must be called from block synchronized on conChild.getConnectionSynchronization.
    
    Parameters:
    
    conChild - ConnectionChild to get synchronization object before accessing PositionedStoreStream
    
    in - InputStream
    
    parent - Parent of the stream to prevent it from being gc.
    
    Throws:
    
    java.io.IOException - if an I/O error occurs
- Method Detail
  - read
```
public int read()
         throws java.io.IOException
```
    Reads a single byte from the underlying stream.
    
    Overrides:
    
    read in class java.io.FilterInputStream
    
    Returns:
    
    The next byte of data, or -1 if the end of the stream is reached.
    
    Throws:
    
    java.io.IOException - if an I/O error occurs
  - read
```
public int read(byte[] b,
                int off,
                int len)
         throws java.io.IOException
```
    Reads a number of bytes from the underlying stream and stores them in the specified byte array at the specified offset.
    
    Overrides:
    
    read in class java.io.FilterInputStream
    
    Returns:
    
    The actual number of bytes read, or -1 if the end of the stream is reached.
    
    Throws:
    
    java.io.IOException - if an I/O error occurs
  - skip
```
public long skip(long n)
          throws java.io.IOException
```
    Skips up to the specified number of bytes from the underlying stream.
    
    Overrides:
    
    skip in class java.io.FilterInputStream
    
    Returns:
    
    The actual number of bytes skipped.
    
    Throws:
    
    java.io.IOException - if an I/O error occurs
  - read
```
public int read(byte[] b)
         throws java.io.IOException
```
    Reads a number of bytes from the underlying stream and stores them in the specified byte array.
    
    Overrides:
    
    read in class java.io.FilterInputStream
    
    Returns:
    
    The actual number of bytes read, or -1 if the end of the stream is reached.
    
    Throws:
    
    java.io.IOException - if an I/O error occurs
  - setPosition
```
private void setPosition()
                  throws java.io.IOException
```
    Checks if positionedStream's position was changed since last used, sets the position to right position if its changed.
    
    Throws:
    
    java.io.IOException

Class AutoPositioningStream

Field Summary

Fields inherited from class java.io.FilterInputStream

Constructor Summary

Method Summary

Methods inherited from class org.apache.derby.impl.jdbc.BinaryToRawStream

Methods inherited from class java.io.FilterInputStream

Methods inherited from class java.io.InputStream

Methods inherited from class java.lang.Object

Field Detail

conChild

pos

positionedStream

Constructor Detail

AutoPositioningStream

Method Detail

read

read

skip

read

setPosition