org.h2.store

Class Data

java.lang.Object

org.h2.store.Data

public class Data
extends java.lang.Object

This class represents a byte buffer that contains persistent data of a page.

Method Summary

Modifier and Type	Method and Description
void	checkCapacity(int plus) Check if there is still enough capacity in the buffer.
static void	copyString(java.io.Reader source, java.io.OutputStream target) Copy a String from a reader to an output stream.
static Data	create(int capacity) Create a new buffer.
void	fillAligned() Fill up the buffer with empty space and an (initially empty) checksum until the size is a multiple of Constants.FILE_BLOCK_SIZE.
byte[]	getBytes() Get the byte array used for this page.
int	length() Get the current write position of this buffer, which is the current length.
void	read(byte[] buff, int off, int len) Copy a number of bytes to the given buffer from the current position.
byte	readByte() Read one single byte.
int	readInt() Read an integer at the current position.
void	reset() Set the position to 0.
void	setPos(int pos) Set the current read / write position.
void	write(byte[] buff, int off, int len) Append a number of bytes to this buffer.
void	writeInt(int x) Write an integer at the current position.

Methods inherited from class java.lang.Object

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

Method Detail

writeInt

public void writeInt(int x)

Write an integer at the current position. The current position is incremented.

Parameters:

x - the value

readInt

public int readInt()

Read an integer at the current position. The current position is incremented.

Returns:

the value

create

public static Data create(int capacity)

Create a new buffer.

Parameters:

capacity - the initial capacity of the buffer

Returns:

the buffer

length

public int length()

Get the current write position of this buffer, which is the current length.

Returns:

the length

getBytes

public byte[] getBytes()

Get the byte array used for this page.

Returns:

the byte array

reset

public void reset()

Set the position to 0.

write

public void write(byte[] buff,
                  int off,
                  int len)

Append a number of bytes to this buffer.

Parameters:

buff - the data

off - the offset in the data

len - the length in bytes

read

public void read(byte[] buff,
                 int off,
                 int len)

Copy a number of bytes to the given buffer from the current position. The current position is incremented accordingly.

Parameters:

buff - the output buffer

off - the offset in the output buffer

len - the number of bytes to copy

setPos

public void setPos(int pos)

Set the current read / write position.

Parameters:

pos - the new position

readByte

public byte readByte()

Read one single byte.

Returns:

the value

checkCapacity

public void checkCapacity(int plus)

Check if there is still enough capacity in the buffer. This method extends the buffer if required.

Parameters:

plus - the number of additional bytes required

fillAligned

public void fillAligned()

Fill up the buffer with empty space and an (initially empty) checksum until the size is a multiple of Constants.FILE_BLOCK_SIZE.

copyString

public static void copyString(java.io.Reader source,
                              java.io.OutputStream target)
                       throws java.io.IOException

Copy a String from a reader to an output stream.

Parameters:

source - the reader

target - the output stream

Throws:

java.io.IOException - on failure