com.mapr.db.rowcol

Class TimeDescriptor

java.lang.Object

com.mapr.db.rowcol.TimeDescriptor

public class TimeDescriptor
extends java.lang.Object

Timedescriptor: contains information about three types 1.CreateTime 2.UpdateTime 3.DeleteTime Each stored time contains two parts - Time in milliseconds and uniqifier. Uniqifier is optional and is stored when the same row gets multiple updates within the same millisecond time. In most cases, uniqifier will be zero. It will not be stored if it's zero. TimeDescriptor is stored as 1 mandatory byte. There are two bits in timedesc for each type. For Create, Update, and Delete time, there are 2 bits for each type that have the following meanings: 0x0 - Field is not valid 0x1 - Field is valid and the time is the same as reftime (both ts + uniq) 0x2 - Field is valid and the external timeinfo is in sizeByte following this SizeByte format is 2 bytes long and stored in little endian format. It stores the information about external time for each of the three timestamps listed above. There are 5 bits for each time type that have the following meanings: bit 0 - bit 2 : Sign and size of the diff 0x0 - time is same as base ts 0x1 - time is +ve diff of base rowtime and diff is 1 byte long 0x2 - time is +ve diff of base rowtime and diff is 2 byte long 0x3 - time is +ve diff of base rowtime and diff is 4 byte long 0x4 - time is absolute and is 6 byte long 0x5 - time is -ve diff of base rowtime and diff is 4 byte long 0x6 - time is -ve diff of base rowtime and diff is 2 byte long 0x7 - time is -ve diff of base rowtime and diff is 1 byte long bit 3-4 : size of uniq 0x0 - uniq is 0 0x1 - uniq is abs and 1 byte long 0x2 - uniq is abs and 2 byte long 0x3 - uniq is abs and 4 byte long There are two modes of storing the timestamp: 1. StoreFullTimestamp = false. This is the default mode when table replication is not enabled. In this mode we don't store the full timestamp for a field. If the time for a field is valid then we store a flag indicating that the time is the same as updatetime for the row. Only update time is stored in full. This is not a problem because we don't expect out of order updates without table replication. 2. StoreFullTimestamp = true. This is true when a table is involved in replication. In this mode we store the full timestamp for each entry with the encoding shown above. At the time of reading the timestamp, if the row was created without storefulltimestamp then it must not have the external ts and any valid timestamp will be converted to the update timestamp of the row. Whether a row is created with storefulltimestamp flag or not, the flag is stored in the rootimedescriptor for the row. When a client sends an op, it will always send the op with storefulltimestamp = false because it has updatetime and all relative times are the same as updatetime.

Field Summary

Fields

Modifier and Type	Field and Description
static int	CreateTimeIndex
static int	CreateTimeMask
static int	CreateTimeShift
static int	DeleteTimeIndex
static int	DeleteTimeMask
static int	DeleteTimeShift
static int	UpdateTimeIndex
static int	UpdateTimeMask
static int	UpdateTimeShift

Constructor Summary

Constructors

Constructor and Description
TimeDescriptor()

Method Summary

Methods

Modifier and Type	Method and Description
static byte	deserialize(KeyValue v, java.nio.ByteBuffer r, SerializationContext ctx)
static byte	getTimeDescriptor(java.nio.ByteBuffer r)
static boolean	isCreateTimeValid(byte timeDescriptor)
static boolean	isCreateTimeValid(KeyValue kv)
static boolean	isDeleteTimeValid(byte timeDescriptor)
static boolean	isDeleteTimeValid(KeyValue kv)
static boolean	isExternal(com.mapr.db.rowcol.TimeDescriptor.TimeStampState t, byte desc)
static boolean	isUpdateTimeValid(byte timeDescriptor)
static boolean	isUpdateTimeValid(KeyValue kv)
static void	reset(KeyValue kv)
static byte	resetCreateTime(byte timeDescriptor)
static void	resetCreateTime(KeyValue kv)
static byte	resetDeleteTime(byte timeDescriptor)
static byte	resetUpdateTime(byte timeDescriptor)
static void	resetUpdateTime(KeyValue kv)
static void	serialize(KeyValue kv, ByteWriter w)
static void	serialize(KeyValue kv, ByteWriter w, SerializationContext ctx)
static void	setCreateTimeValid(KeyValue kv)
static int	setCreateTimeValidHelper()
static int	setDeleteTimeValid()
static void	setDeleteTimeValid(KeyValue kv)
static int	setUpdateTimeValid()
static void	setUpdateTimeValid(KeyValue kv)
static java.lang.String	toStringWithTimestamp(KeyValue v)

Methods inherited from class java.lang.Object

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

Field Detail

CreateTimeIndex

public static final int CreateTimeIndex

See Also:

Constant Field Values

UpdateTimeIndex

public static final int UpdateTimeIndex

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Constant Field Values

DeleteTimeIndex

public static final int DeleteTimeIndex

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Constant Field Values

CreateTimeShift

public static final int CreateTimeShift

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Constant Field Values

CreateTimeMask

public static final int CreateTimeMask

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Constant Field Values

UpdateTimeShift

public static final int UpdateTimeShift

See Also:

Constant Field Values

UpdateTimeMask

public static final int UpdateTimeMask

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Constant Field Values

DeleteTimeShift

public static final int DeleteTimeShift

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Constant Field Values

DeleteTimeMask

public static final int DeleteTimeMask

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Constant Field Values

Constructor Detail

TimeDescriptor

public TimeDescriptor()

Method Detail

reset

public static void reset(KeyValue kv)

setCreateTimeValid

public static void setCreateTimeValid(KeyValue kv)

setCreateTimeValidHelper

public static int setCreateTimeValidHelper()

isCreateTimeValid

public static boolean isCreateTimeValid(byte timeDescriptor)

isCreateTimeValid

public static boolean isCreateTimeValid(KeyValue kv)

setDeleteTimeValid

public static void setDeleteTimeValid(KeyValue kv)

setDeleteTimeValid

public static int setDeleteTimeValid()

isDeleteTimeValid

public static boolean isDeleteTimeValid(KeyValue kv)

isDeleteTimeValid

public static boolean isDeleteTimeValid(byte timeDescriptor)

setUpdateTimeValid

public static void setUpdateTimeValid(KeyValue kv)

setUpdateTimeValid

public static int setUpdateTimeValid()

isUpdateTimeValid

public static boolean isUpdateTimeValid(KeyValue kv)

isUpdateTimeValid

public static boolean isUpdateTimeValid(byte timeDescriptor)

resetCreateTime

public static byte resetCreateTime(byte timeDescriptor)

resetCreateTime

public static void resetCreateTime(KeyValue kv)

resetUpdateTime

public static void resetUpdateTime(KeyValue kv)

resetUpdateTime

public static byte resetUpdateTime(byte timeDescriptor)

resetDeleteTime

public static byte resetDeleteTime(byte timeDescriptor)

serialize

public static void serialize(KeyValue kv,
             ByteWriter w,
             SerializationContext ctx)

serialize

public static void serialize(KeyValue kv,
             ByteWriter w)

getTimeDescriptor

public static byte getTimeDescriptor(java.nio.ByteBuffer r)

isExternal

public static boolean isExternal(com.mapr.db.rowcol.TimeDescriptor.TimeStampState t,
                 byte desc)

deserialize

public static byte deserialize(KeyValue v,
               java.nio.ByteBuffer r,
               SerializationContext ctx)

toStringWithTimestamp

public static java.lang.String toStringWithTimestamp(KeyValue v)