org.apache.hadoop.hive.serde2.io
Class TimestampWritable

java.lang.Object
  org.apache.hadoop.hive.serde2.io.TimestampWritable

All Implemented Interfaces:

Comparable<TimestampWritable>, org.apache.hadoop.io.Writable, org.apache.hadoop.io.WritableComparable<TimestampWritable>

public class TimestampWritable
extends Object
implements org.apache.hadoop.io.WritableComparable<TimestampWritable>

TimestampWritable Writable equivalent of java.sq.Timestamp Timestamps are of the format YYYY-MM-DD HH:MM:SS.[fff...] We encode Unix timestamp in seconds in 4 bytes, using the MSB to signify whether the timestamp has a fractional portion. The fractional portion is reversed, and encoded as a VInt so timestamps with less precision use fewer bytes. 0.1 -> 1 0.01 -> 10 0.001 -> 100

Field Summary

static byte[]

nullBytes

Constructor Summary

TimestampWritable()

TimestampWritable(byte[] bytes, int offset)

TimestampWritable(Timestamp t)

TimestampWritable(TimestampWritable t)

Method Summary

int	compareTo(TimestampWritable t)
static void	convertTimestampToBytes(Timestamp t, byte[] b, int offset) Writes a Timestamp's serialized value to byte array b at
static Timestamp	createTimestamp(byte[] bytes, int offset)
static Timestamp	doubleToTimestamp(double f)
boolean	equals(Object o)
static Timestamp	floatToTimestamp(float f) Interprets a float as a unix timestamp and returns a Timestamp object
byte[]	getBinarySortable()
byte[]	getBytes() Used to create copies of objects
double	getDouble()
int	getNanos()
static int	getNanos(byte[] bytes, int offset)
int	getSeconds()
static int	getSeconds(byte[] bytes, int offset) Gets seconds stored as integer at bytes[offset]
Timestamp	getTimestamp()
boolean	hasDecimal()
static boolean	hasDecimal(byte b)
int	hashCode()
void	readFields(DataInput in)
void	set(byte[] bytes, int offset)
void	set(Timestamp t)
void	set(TimestampWritable t)
void	setBinarySortable(byte[] bytes, int offset) Given a byte[] that has binary sortable data, initialize the internal structures to hold that data
static void	setTimestamp(Timestamp t, byte[] bytes, int offset)
String	toString()
void	write(DataOutput out)
void	write(OutputStream out)
void	writeToByteStream(ByteStream.Output byteStream)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

nullBytes

public static final byte[] nullBytes

Constructor Detail

TimestampWritable

public TimestampWritable()

TimestampWritable

public TimestampWritable(byte[] bytes,
                         int offset)

TimestampWritable

public TimestampWritable(TimestampWritable t)

TimestampWritable

public TimestampWritable(Timestamp t)

Method Detail

set

public void set(byte[] bytes,
                int offset)

set

public void set(Timestamp t)

set

public void set(TimestampWritable t)

writeToByteStream

public void writeToByteStream(ByteStream.Output byteStream)

getSeconds

public int getSeconds()

Returns:

seconds corresponding to this TimestampWritable

getNanos

public int getNanos()

Returns:

nanoseconds in this TimestampWritable

getTimestamp

public Timestamp getTimestamp()

getBytes

public byte[] getBytes()

Used to create copies of objects

Returns:

a copy of the internal TimestampWritable byte[]

getBinarySortable

public byte[] getBinarySortable()

Returns:

byte[] representation of TimestampWritable that is binary sortable (4 byte seconds, 4 bytes for nanoseconds)

setBinarySortable

public void setBinarySortable(byte[] bytes,
                              int offset)

Given a byte[] that has binary sortable data, initialize the internal structures to hold that data

Parameters:

bytes -

offset -

getDouble

public double getDouble()

Returns:

double representation of the timestamp, accurate to nanoseconds

readFields

public void readFields(DataInput in)
                throws IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

IOException

write

public void write(OutputStream out)
           throws IOException

Throws:

IOException

write

public void write(DataOutput out)
           throws IOException

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

IOException

compareTo

public int compareTo(TimestampWritable t)

Specified by:

compareTo in interface Comparable<TimestampWritable>

equals

public boolean equals(Object o)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

getSeconds

public static int getSeconds(byte[] bytes,
                             int offset)

Gets seconds stored as integer at bytes[offset]

Parameters:

bytes -

offset -

Returns:

the number of seconds

getNanos

public static int getNanos(byte[] bytes,
                           int offset)

convertTimestampToBytes

public static void convertTimestampToBytes(Timestamp t,
                                           byte[] b,
                                           int offset)

Writes a Timestamp's serialized value to byte array b at

Parameters:

t -

b -

floatToTimestamp

public static Timestamp floatToTimestamp(float f)

Interprets a float as a unix timestamp and returns a Timestamp object

Parameters:

f -

Returns:

the equivalent Timestamp object

doubleToTimestamp

public static Timestamp doubleToTimestamp(double f)

setTimestamp

public static void setTimestamp(Timestamp t,
                                byte[] bytes,
                                int offset)

createTimestamp

public static Timestamp createTimestamp(byte[] bytes,
                                        int offset)

hasDecimal

public boolean hasDecimal()

hasDecimal

public static boolean hasDecimal(byte b)

Parameters:

b - first byte in an encoded TimestampWritable

Returns:

true if it has a decimal portion, false otherwise