org.apache.derby.iapi.services.io
Class ArrayInputStream

java.lang.Object
  java.io.InputStream
      org.apache.derby.iapi.services.io.ArrayInputStream

All Implemented Interfaces:

java.io.Closeable, java.io.DataInput, java.io.ObjectInput, ErrorInfo, ErrorObjectInput, Limit, LimitObjectInput

public final class ArrayInputStream
extends java.io.InputStream
implements LimitObjectInput

An InputStream that allows reading from an array of bytes. The array of bytes that is read from can be changed without having to create a new instance of this class.

Field Summary

private int	end
private ErrorObjectInput	oi
private byte[]	pageData
private int	position
private int	start

Constructor Summary

ArrayInputStream()
Create an ArrayInputStream with a zero length byte array.

ArrayInputStream(byte[] data)
Create an ArrayInputStream with the passed in data.

Method Summary

int	available()
int	clearLimit() Clears the limit by setting the limit to be the entire byte array.
byte[]	getData() Return a reference to the array of bytes this stream is going to read from so that caller may load it with stuff
java.lang.String	getErrorInfo()
java.lang.Exception	getNestedException()
int	getPosition()
int	read()
int	read(byte[] b, int off, int len)
boolean	readBoolean()
byte	readByte()
char	readChar()
int	readCompressedInt() Read a compressed int from the stream.
long	readCompressedLong() Read a compressed long from the stream.
int	readDerbyUTF(char[][] rawData_array, int utflen) read in a Derby UTF formated string into a char[].
double	readDouble()
float	readFloat()
void	readFully(byte[] b)
void	readFully(byte[] b, int off, int len)
int	readInt()
java.lang.String	readLine()
long	readLong()
java.lang.Object	readObject()
short	readShort()
int	readUnsignedByte()
int	readUnsignedShort()
java.lang.String	readUTF()
void	setData(byte[] data) Set the array of bytes to be read.
void	setLimit(int length) Set the limit of the data that can be read or written.
void	setLimit(int offset, int length) A setLimit which also sets the position to be offset.
void	setPosition(int newPosition)
long	skip(long count) Skip as many bytes as possible, but no more than count.
int	skipBytes(int n) Skip as many bytes as possible, but no more than n.

Methods inherited from class java.io.InputStream

close, mark, markSupported, read, reset

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.io.ObjectInput

close, read

Field Detail

pageData

private byte[] pageData

start

private int start

end

private int end

position

private int position

oi

private ErrorObjectInput oi

Constructor Detail

ArrayInputStream

public ArrayInputStream()

Create an ArrayInputStream with a zero length byte array. The position is set to 0 and the limit is the entire byte array.

ArrayInputStream

public ArrayInputStream(byte[] data)

Create an ArrayInputStream with the passed in data. The position is set to 0 and the limit is the entire byte array.

Parameters:

data -

Method Detail

setData

public void setData(byte[] data)

Set the array of bytes to be read. Position is set to zero.

getData

public byte[] getData()

Return a reference to the array of bytes this stream is going to read from so that caller may load it with stuff

read

public int read()
         throws java.io.IOException

Specified by:

read in interface java.io.ObjectInput

Specified by:

read in class java.io.InputStream

Throws:

java.io.IOException

read

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

Specified by:

read in interface java.io.ObjectInput

Overrides:

read in class java.io.InputStream

Throws:

java.io.IOException

skip

public long skip(long count)
          throws java.io.IOException

Skip as many bytes as possible, but no more than count.

Specified by:

skip in interface java.io.ObjectInput

Overrides:

skip in class java.io.InputStream

Parameters:

count - the number of bytes to skip

Returns:

the number of bytes that were skipped

Throws:

java.io.IOException

getPosition

public int getPosition()

setPosition

public final void setPosition(int newPosition)
                       throws java.io.IOException

Throws:

java.io.IOException

available

public int available()
              throws java.io.IOException

Specified by:

available in interface java.io.ObjectInput

Overrides:

available in class java.io.InputStream

Throws:

java.io.IOException

setLimit

public void setLimit(int offset,
                     int length)
              throws java.io.IOException

A setLimit which also sets the position to be offset.

Throws:

java.io.IOException - limit is out of range

setLimit

public final void setLimit(int length)
                    throws java.io.IOException

Description copied from interface: Limit

Set the limit of the data that can be read or written. After this call up to and including length bytes can be read from or skipped in the stream.

On input classes (e.g. InputStreams) any attempt to read or skip beyond the limit will result in an end of file indication (e.g. read() methods returning -1 or throwing EOFException).

On output classes (e.g. OutputStream) any attempt to write more beyond the limit will result in an EOFException

Specified by:

setLimit in interface Limit

Throws:

java.io.IOException - IOException from some underlying stream

clearLimit

public final int clearLimit()

Clears the limit by setting the limit to be the entire byte array.

Specified by:

clearLimit in interface Limit

Returns:

the number of bytes within the limit that have not been read or written.

See Also:

Limit.clearLimit()

readFully

public final void readFully(byte[] b)
                     throws java.io.IOException

Specified by:

readFully in interface java.io.DataInput

Throws:

java.io.IOException

readFully

public final void readFully(byte[] b,
                            int off,
                            int len)
                     throws java.io.IOException

Specified by:

readFully in interface java.io.DataInput

Throws:

java.io.IOException

skipBytes

public final int skipBytes(int n)
                    throws java.io.IOException

Skip as many bytes as possible, but no more than n.

Specified by:

skipBytes in interface java.io.DataInput

Parameters:

n - the number of bytes to skip

Returns:

the number of bytes that were skipped

Throws:

java.io.IOException

readBoolean

public final boolean readBoolean()
                          throws java.io.IOException

Specified by:

readBoolean in interface java.io.DataInput

Throws:

java.io.IOException

readByte

public final byte readByte()
                    throws java.io.IOException

Specified by:

readByte in interface java.io.DataInput

Throws:

java.io.IOException

readUnsignedByte

public final int readUnsignedByte()
                           throws java.io.IOException

Specified by:

readUnsignedByte in interface java.io.DataInput

Throws:

java.io.IOException

readShort

public final short readShort()
                      throws java.io.IOException

Specified by:

readShort in interface java.io.DataInput

Throws:

java.io.IOException

readUnsignedShort

public final int readUnsignedShort()
                            throws java.io.IOException

Specified by:

readUnsignedShort in interface java.io.DataInput

Throws:

java.io.IOException

readChar

public final char readChar()
                    throws java.io.IOException

Specified by:

readChar in interface java.io.DataInput

Throws:

java.io.IOException

readInt

public final int readInt()
                  throws java.io.IOException

Specified by:

readInt in interface java.io.DataInput

Throws:

java.io.IOException

readLong

public final long readLong()
                    throws java.io.IOException

Specified by:

readLong in interface java.io.DataInput

Throws:

java.io.IOException

readFloat

public final float readFloat()
                      throws java.io.IOException

Specified by:

readFloat in interface java.io.DataInput

Throws:

java.io.IOException

readDouble

public final double readDouble()
                        throws java.io.IOException

Specified by:

readDouble in interface java.io.DataInput

Throws:

java.io.IOException

readLine

public final java.lang.String readLine()
                                throws java.io.IOException

Specified by:

readLine in interface java.io.DataInput

Throws:

java.io.IOException

readUTF

public final java.lang.String readUTF()
                               throws java.io.IOException

Specified by:

readUTF in interface java.io.DataInput

Throws:

java.io.IOException

readDerbyUTF

public final int readDerbyUTF(char[][] rawData_array,
                              int utflen)
                       throws java.io.IOException

read in a Derby UTF formated string into a char[].

This routine inline's the code to read a UTF format string from a byte[] array (pageData), into a char[] array. The string will be read into the char[] array passed into this routine through rawData_array[0] if it is big enough. If it is not big enough a new char[] will be alocated and returned to the caller by putting it into rawData_array[0].

To see detailed description of the Derby UTF format see the writeExternal() routine of SQLChar.

The routine returns the number of char's read into the returned char[], note that this length may smaller than the actual length of the char[] array.

The stream must be positioned on the first user byte when this method is invoked.

Parameters:

rawData_array - This parameter uses a element array to implement an in/out function parameter. The char[] array in rawData_array[0] is used to read the data into unless it is not big enough, then a new array is allocated and the old one discarded. In either case on return rawData_array[0] contains the filled in char[] - caller must allow that the array may or may not be different from the one passed in.

utflen - the byte length of the value, or 0 if unknown

Returns:

The the number of valid char's in the returned char[].

Throws:

StandardException - Standard exception policy.

java.io.IOException

readCompressedInt

public final int readCompressedInt()
                            throws java.io.IOException

Read a compressed int from the stream.

Read a compressed int from the stream, which is assumed to have been written by a call to CompressNumber.writeInt().

Code from CompressedNumber is inlined here so that these fields can be read from the array with a minimum of function calls.

The format of a compressed int is as follows: Formats are (with x representing value bits):

 1 Byte- 00xxxxxx                            val <= 63 (0x3f)
 2 Byte- 01xxxxxx xxxxxxxx                   val > 63 && <= 16383 (0x3fff)
 4 byte- 1xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx val > 16383 && <= MAX_INT
 

Throws:

StandardException - Standard exception policy.

java.io.IOException

readCompressedLong

public final long readCompressedLong()
                              throws java.io.IOException

Read a compressed long from the stream.

Read a compressed long from the stream, which is assumed to have been written by a call to CompressNumber.writeLong().

Code from CompressedNumber is inlined here so that these fields can be read from the array with a minimum of function calls.

The format of a compressed int is as follows: Formats are (with x representing value bits):

 value <= 16383 (0x3fff): 
     2 byte - 00xxxxxx xxxxxxxx 

 value > 16383 && <= 0x3fffffff:
     4 byte - 01xxxxxx xxxxxxxx xxxxxxxx xxxxxxxx

 value > 0x3fffffff && <= MAX_LONG:
     8 byte - 1xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
 

Throws:

java.io.IOException

readObject

public java.lang.Object readObject()
                            throws java.lang.ClassNotFoundException,
                                   java.io.IOException

Specified by:

readObject in interface java.io.ObjectInput

Throws:

java.lang.ClassNotFoundException

java.io.IOException

getErrorInfo

public java.lang.String getErrorInfo()

Specified by:

getErrorInfo in interface ErrorInfo

Specified by:

getErrorInfo in interface ErrorObjectInput

getNestedException

public java.lang.Exception getNestedException()

Specified by:

getNestedException in interface ErrorInfo

Specified by:

getNestedException in interface ErrorObjectInput