Data

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

Methods
static void	copyString(Reader source, OutputStream target) Copy a String from a reader to an output stream.
static void	copyString(Reader source, OutputStream target) throws IOException Copy a String from a reader to an output stream. Parameters: source - the reader target - the output stream
static Data	create(DataHandler handler, int capacity) Create a new buffer for the given handler.
static Data	create(DataHandler handler, int capacity) Create a new buffer for the given handler. The handler will decide what type of buffer is created. Parameters: handler - the data handler capacity - the initial capacity of the buffer Returns: the buffer
static Data	create(DataHandler handler, byte[] buff) Create a new buffer using the given data for the given handler.
static Data	create(DataHandler handler, byte[] buff) Create a new buffer using the given data for the given handler. The handler will decide what type of buffer is created. Parameters: handler - the data handler buff - the data Returns: the buffer
static int	getStringLen(String s) Get the length of a String.
static int	getStringLen(String s) Get the length of a String. This includes the bytes required to encode the length. Parameters: s - the string Returns: the number of bytes required
static int	getValueLen(Value v, DataHandler handler) Calculate the number of bytes required to encode the given value.
static int	getValueLen(Value v, DataHandler handler) Calculate the number of bytes required to encode the given value. Parameters: v - the value handler - the data handler for lobs Returns: the number of bytes required to store this value
static int	getVarLongLen(long x) The number of bytes required for a variable size long.
static int	getVarLongLen(long x) The number of bytes required for a variable size long. Parameters: x - the value Returns: the len
void	checkCapacity(int plus) Check if there is still enough capacity in the buffer.
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
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.
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.
byte[]	getBytes() Get the byte array used for this page. Returns: the byte array
DataHandler	getHandler()
DataHandler	getHandler()
int	getValueLen(Value v) Calculate the number of bytes required to encode the given value.
int	getValueLen(Value v) Calculate the number of bytes required to encode the given value. Parameters: v - the value Returns: the number of bytes required to store this value
int	length() Get the current write position of this buffer, which is the current length.
int	length() Get the current write position of this buffer, which is the current length. Returns: the length
void	read(byte[] buff, int off, int len) Copy a number of bytes to the given buffer from the current position.
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
byte	readByte() Read one single byte.
byte	readByte() Read one single byte. Returns: the value
int	readInt() Read an integer at the current position.
int	readInt() Read an integer at the current position. The current position is incremented. Returns: the value
long	readLong() Read a long value.
long	readLong() Read a long value. This method reads two int values and combines them. Returns: the long value
short	readShortInt() Read an short integer at the current position.
short	readShortInt() Read an short integer at the current position. The current position is incremented. Returns: the value
String	readString() Read a String value.
String	readString() Read a String value. The current position is incremented. Returns: the value
Value	readValue() Read a value.
Value	readValue() Read a value. Returns: the value
int	readVarInt() Read a variable size int.
int	readVarInt() Read a variable size int. Returns: the value
long	readVarLong() Read a variable size long.
long	readVarLong() Read a variable size long. Returns: the value
void	reset() Set the position to 0.
void	reset() Set the position to 0.
void	setInt(int pos, int x) Update an integer at the given position.
void	setInt(int pos, int x) Update an integer at the given position. The current position is not change. Parameters: pos - the position x - the value
void	setPos(int pos) Set the current read / write position.
void	setPos(int pos) Set the current read / write position. Parameters: pos - the new position
void	truncate(int size) Shrink the array to this size.
void	truncate(int size) Shrink the array to this size. Parameters: size - the new size
void	write(byte[] buff, int off, int len) Append a number of bytes to this buffer.
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
void	writeByte(byte x) Append one single byte.
void	writeByte(byte x) Append one single byte. Parameters: x - the value
void	writeInt(int x) Write an integer at the current position.
void	writeInt(int x) Write an integer at the current position. The current position is incremented. Parameters: x - the value
void	writeLong(long x) Append a long value.
void	writeLong(long x) Append a long value. This method writes two int values. Parameters: x - the value
void	writeShortInt(int x) Write a short integer at the current position.
void	writeShortInt(int x) Write a short integer at the current position. The current position is incremented. Parameters: x - the value
void	writeString(String s) Write a String.
void	writeString(String s) Write a String. The current position is incremented. Parameters: s - the value
void	writeValue(Value v) Append a value.
void	writeValue(Value v) Append a value. Parameters: v - the value
void	writeVarInt(int x) Write a variable size int.
void	writeVarInt(int x) Write a variable size int. Parameters: x - the value
void	writeVarLong(long x) Write a variable size long.
void	writeVarLong(long x) Write a variable size long. Parameters: x - the value

Fields
static int	LENGTH_INT = 4

LENGTH_INT = 4

The length of an integer value.