com.sleepycat.util
Class PackedInteger

java.lang.Object
  com.sleepycat.util.PackedInteger

public class PackedInteger
extends Object

Static methods for reading and writing packed integers.

Most applications should use the classes in the com.sleepycat.bind.tuple package rather than using this class directly.

See Also:

Integer Formats

Field Summary

static int	MAX_LENGTH The maximum number of bytes needed to store an int value (5).
static int	MAX_LONG_LENGTH The maximum number of bytes needed to store a long value (9).

Constructor Summary

PackedInteger()

Method Summary

static int	getReadIntLength(byte[] buf, int off) Returns the number of bytes that would be read by readInt(byte[], int).
static int	getReadLongLength(byte[] buf, int off) Returns the number of bytes that would be read by readLong(byte[], int).
static int	getReadSortedIntLength(byte[] buf, int off) Returns the number of bytes that would be read by readSortedInt(byte[], int).
static int	getReadSortedLongLength(byte[] buf, int off) Returns the number of bytes that would be read by readSortedLong(byte[], int).
static int	getWriteIntLength(int value) Returns the number of bytes that would be written by writeInt(byte[], int, int).
static int	getWriteLongLength(long value) Returns the number of bytes that would be written by writeLong(byte[], int, long).
static int	getWriteSortedIntLength(int value) Returns the number of bytes that would be written by writeSortedInt(byte[], int, int).
static int	getWriteSortedLongLength(long value) Returns the number of bytes that would be written by writeSortedLong(byte[], int, long).
static int	readInt(byte[] buf, int off) Reads a packed integer at the given buffer offset and returns it.
static long	readLong(byte[] buf, int off) Reads a packed long integer at the given buffer offset and returns it.
static int	readSortedInt(byte[] buf, int off) Reads a sorted packed integer at the given buffer offset and returns it.
static long	readSortedLong(byte[] buf, int off) Reads a sorted packed long integer at the given buffer offset and returns it.
static int	writeInt(byte[] buf, int offset, int value) Writes a packed integer starting at the given buffer offset and returns the next offset to be written.
static int	writeLong(byte[] buf, int offset, long value) Writes a packed long integer starting at the given buffer offset and returns the next offset to be written.
static int	writeSortedInt(byte[] buf, int offset, int value) Writes a packed sorted integer starting at the given buffer offset and returns the next offset to be written.
static int	writeSortedLong(byte[] buf, int offset, long value) Writes a packed sorted long integer starting at the given buffer offset and returns the next offset to be written.

Methods inherited from class java.lang.Object

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

Field Detail

MAX_LENGTH

public static final int MAX_LENGTH

The maximum number of bytes needed to store an int value (5).

See Also:

Constant Field Values

MAX_LONG_LENGTH

public static final int MAX_LONG_LENGTH

The maximum number of bytes needed to store a long value (9).

See Also:

Constant Field Values

Constructor Detail

PackedInteger

public PackedInteger()

Method Detail

readInt

public static int readInt(byte[] buf,
                          int off)

Reads a packed integer at the given buffer offset and returns it.

Parameters:

buf - the buffer to read from.

off - the offset in the buffer at which to start reading.

Returns:

the integer that was read.

readLong

public static long readLong(byte[] buf,
                            int off)

Reads a packed long integer at the given buffer offset and returns it.

Parameters:

buf - the buffer to read from.

off - the offset in the buffer at which to start reading.

Returns:

the long integer that was read.

getReadIntLength

public static int getReadIntLength(byte[] buf,
                                   int off)

Returns the number of bytes that would be read by readInt(byte[], int).

Because the length is stored in the first byte, this method may be called with only the first byte of the packed integer in the given buffer. This method only accesses one byte at the given offset.

Parameters:

buf - the buffer to read from.

off - the offset in the buffer at which to start reading.

Returns:

the number of bytes that would be read.

getReadLongLength

public static int getReadLongLength(byte[] buf,
                                    int off)

Returns the number of bytes that would be read by readLong(byte[], int).

Because the length is stored in the first byte, this method may be called with only the first byte of the packed integer in the given buffer. This method only accesses one byte at the given offset.

Parameters:

buf - the buffer to read from.

off - the offset in the buffer at which to start reading.

Returns:

the number of bytes that would be read.

writeInt

public static int writeInt(byte[] buf,
                           int offset,
                           int value)

Writes a packed integer starting at the given buffer offset and returns the next offset to be written.

Parameters:

buf - the buffer to write to.

offset - the offset in the buffer at which to start writing.

value - the integer to be written.

Returns:

the offset past the bytes written.

writeLong

public static int writeLong(byte[] buf,
                            int offset,
                            long value)

Writes a packed long integer starting at the given buffer offset and returns the next offset to be written.

Parameters:

buf - the buffer to write to.

offset - the offset in the buffer at which to start writing.

value - the long integer to be written.

Returns:

the offset past the bytes written.

getWriteIntLength

public static int getWriteIntLength(int value)

Returns the number of bytes that would be written by writeInt(byte[], int, int).

Parameters:

value - the integer to be written.

Returns:

the number of bytes that would be used to write the given integer.

getWriteLongLength

public static int getWriteLongLength(long value)

Returns the number of bytes that would be written by writeLong(byte[], int, long).

Parameters:

value - the long integer to be written.

Returns:

the number of bytes that would be used to write the given long integer.

readSortedInt

public static int readSortedInt(byte[] buf,
                                int off)

Reads a sorted packed integer at the given buffer offset and returns it.

Parameters:

buf - the buffer to read from.

off - the offset in the buffer at which to start reading.

Returns:

the integer that was read.

readSortedLong

public static long readSortedLong(byte[] buf,
                                  int off)

Reads a sorted packed long integer at the given buffer offset and returns it.

Parameters:

buf - the buffer to read from.

off - the offset in the buffer at which to start reading.

Returns:

the long integer that was read.

getReadSortedIntLength

public static int getReadSortedIntLength(byte[] buf,
                                         int off)

Returns the number of bytes that would be read by readSortedInt(byte[], int).

Because the length is stored in the first byte, this method may be called with only the first byte of the packed integer in the given buffer. This method only accesses one byte at the given offset.

Parameters:

buf - the buffer to read from.

off - the offset in the buffer at which to start reading.

Returns:

the number of bytes that would be read.

getReadSortedLongLength

public static int getReadSortedLongLength(byte[] buf,
                                          int off)

Returns the number of bytes that would be read by readSortedLong(byte[], int).

Because the length is stored in the first byte, this method may be called with only the first byte of the packed integer in the given buffer. This method only accesses one byte at the given offset.

Parameters:

buf - the buffer to read from.

off - the offset in the buffer at which to start reading.

Returns:

the number of bytes that would be read.

writeSortedInt

public static int writeSortedInt(byte[] buf,
                                 int offset,
                                 int value)

Writes a packed sorted integer starting at the given buffer offset and returns the next offset to be written.

Parameters:

buf - the buffer to write to.

offset - the offset in the buffer at which to start writing.

value - the integer to be written.

Returns:

the offset past the bytes written.

writeSortedLong

public static int writeSortedLong(byte[] buf,
                                  int offset,
                                  long value)

Writes a packed sorted long integer starting at the given buffer offset and returns the next offset to be written.

Parameters:

buf - the buffer to write to.

offset - the offset in the buffer at which to start writing.

value - the long integer to be written.

Returns:

the offset past the bytes written.

getWriteSortedIntLength

public static int getWriteSortedIntLength(int value)

Returns the number of bytes that would be written by writeSortedInt(byte[], int, int).

Parameters:

value - the integer to be written.

Returns:

the number of bytes that would be used to write the given integer.

getWriteSortedLongLength

public static int getWriteSortedLongLength(long value)

Returns the number of bytes that would be written by writeSortedLong(byte[], int, long).

Parameters:

value - the long integer to be written.

Returns:

the number of bytes that would be used to write the given long integer.