Module openj9.dtfj

Package com.ibm.dtfj.corereaders.zos.dumpreader

Class AddressSpaceImageInputStream

java.lang.Object

javax.imageio.stream.ImageInputStreamImpl

com.ibm.dtfj.corereaders.zos.dumpreader.AddressSpaceImageInputStream

All Implemented Interfaces:

Closeable, DataInput, AutoCloseable, ImageInputStream

public final class AddressSpaceImageInputStream
extends ImageInputStreamImpl

This class implements ImageInputStream for an AddressSpace. You can use this to read data from an AddressSpace as an alternative to using the methods defined in AddressSpace itself. ImageInputStream provides a rich set of read methods. To use it you must first call seek() with the address you wish to read from and then call the appropriate read method.

Note that at present it doesn't fully meet the ImageInputStream semantics in that it won't skip over gaps in the AddressSpace seamlessly. I might add that functionality if the demand is there. Also length returns -1 since it doesn't make sense to return a real value (?).

Field Summary

Fields declared in class javax.imageio.stream.ImageInputStreamImpl

bitOffset, byteOrder, flushedPos, streamPos

Constructor Summary

Constructors

Constructor	Description
AddressSpaceImageInputStream(AddressSpace space)	Create a new AddressSpaceImageInputStream for the given AddressSpace.

Method Summary

Modifier and Type	Method	Description
int	read()	Read a byte from the current position.
int	read(byte[] b, int off, int len)	Read some bytes from the current position and add len to streamPos.
int	readInt()	Read an int from the current position.
long	readLong()	Read a long from the current position.
long	readUnsignedInt()	Read an unsigned int from the current position.

Methods declared in class javax.imageio.stream.ImageInputStreamImpl

checkClosed, close, finalize, flush, flushBefore, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, isCached, isCachedFile, isCachedMemory, length, mark, read, readBit, readBits, readBoolean, readByte, readBytes, readChar, readDouble, readFloat, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readLine, readShort, readUnsignedByte, readUnsignedShort, readUTF, reset, seek, setBitOffset, setByteOrder, skipBytes, skipBytes

Methods declared in class java.lang.Object

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

Constructor Details

AddressSpaceImageInputStream

public AddressSpaceImageInputStream(AddressSpace space)

Create a new AddressSpaceImageInputStream for the given AddressSpace.

Parameters:

space - the AddressSpace which this stream reads

Method Details

read

public int read()
         throws IOException

Read a byte from the current position. Also increments streamPos.

Specified by:

read in interface ImageInputStream

Specified by:

read in class ImageInputStreamImpl

Returns:

the value of the next byte in the stream, or -1 if EOF is reached.

Throws:

IOException - if the stream has been closed.

read

public int read(byte[] b,
 int off,
 int len)
         throws IOException

Read some bytes from the current position and add len to streamPos.

Specified by:

read in interface ImageInputStream

Specified by:

read in class ImageInputStreamImpl

Parameters:

b - an array of bytes to be written to.

off - the starting position within b to write to.

len - the maximum number of bytes to read.

Returns:

the number of bytes actually read, or -1 to indicate EOF.

Throws:

IOException - if an I/O error occurs.

readInt

public int readInt()
            throws IOException

Read an int from the current position. Also increments streamPos. For efficiency to avoid multiple reads via ImageInputStream

Specified by:

readInt in interface DataInput

Specified by:

readInt in interface ImageInputStream

Overrides:

readInt in class ImageInputStreamImpl

Returns:

a signed int value from the stream.

Throws:

EOFException - if the stream reaches the end before reading all the bytes.

IOException - if an I/O error occurs.

See Also:

• ImageInputStream.getByteOrder()

readUnsignedInt

public long readUnsignedInt()
                     throws IOException

Read an unsigned int from the current position. Also increments streamPos. For efficiency to avoid multiple reads via ImageInputStream

Specified by:

readUnsignedInt in interface ImageInputStream

Overrides:

readUnsignedInt in class ImageInputStreamImpl

Returns:

an unsigned int value from the stream, as a long.

Throws:

EOFException - if the stream reaches the end before reading all the bytes.

IOException - if an I/O error occurs.

See Also:

• ImageInputStream.getByteOrder()

readLong

public long readLong()
              throws IOException

Read a long from the current position. Also increments streamPos. For efficiency to avoid multiple reads via ImageInputStream

Specified by:

readLong in interface DataInput

Specified by:

readLong in interface ImageInputStream

Overrides:

readLong in class ImageInputStreamImpl

Returns:

a signed long value from the stream.

Throws:

EOFException - if the stream reaches the end before reading all the bytes.

IOException - if an I/O error occurs.

See Also:

• ImageInputStream.getByteOrder()