Package oracle.kv.table

Class TimeToLive

java.lang.Object
oracle.kv.table.TimeToLive
All Implemented Interfaces:
Serializable, oracle.kv.impl.util.FastExternalizable
public final class TimeToLive extends Object implements Serializable, oracle.kv.impl.util.FastExternalizable
TimeToLive is a utility class that represents a period of time, similar to Java 8's java.time.Duration, but specialized to the needs of Oracle NoSQL Database.

This class is restricted to durations of days and hours. It is only used as input related to time to live (TTL) for Row instances, set by using Row.setTTL(oracle.kv.table.TimeToLive). Construction allows only day and hour durations for efficiency reasons. Durations of days are recommended as they result in the least amount of storage consumed in a store.

Only positive durations are allowed on input, although negative durations can be returned from fromExpirationTime(long, long) if the expirationTime is in the past relative to the referenceTime.

Since:
4.0
See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final TimeToLive
    DO_NOT_EXPIRE
    A convenience constant that can be used as an argument to Row.setTTL(oracle.kv.table.TimeToLive) to indicate that the row should not expire.

  • Method Summary

    Modifier and Type
    Method
    Description
    static TimeUnit
    convertTimeToLiveUnit(int ttlVal, byte unitOrdinal)
    Converts an ordinal value for a TTL TimeUnit into the TimeUnit.
    boolean
    equals(Object other)
    Equality compares the duration only if the units used for construction are the same.
    static TimeToLive
    fromExpirationTime(long expirationTime, long referenceTime)
    Returns an instance of TimeToLive based on an absolute expiration time and a reference time.
    static TimeUnit
    getTTLUnit(TimeToLive ttl)
    Returns the TimeUnit associated with a TimeToLive, or {TimeUnit#DAYS} if the ttl is null.
    static int
    getTTLValue(TimeToLive ttl)
    Returns the numeric duration value associated with a TimeToLive, or 0 if the ttl is null.
    int
    hashCode()
     
    static TimeToLive
    ofDays(long days)
    Creates a duration using a period of 24 hour days.
    static TimeToLive
    ofHours(long hours)
    Creates a duration using a period of hours.
    long
    toDays()
    Returns the number of days in this duration, which may be negative.
    long
    toExpirationTime(long referenceTime)
    Returns an absolute time representing the duration plus the absolute time reference parameter.
    long
    toHours()
    Returns the number of hours in this duration, which may be negative.
    String
    toString()
     

    Methods inherited from class java.lang.Object

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

    Methods inherited from interface oracle.kv.impl.util.FastExternalizable

    deserializedForm

  • Field Details

  • Method Details

    • ofHours

      public static TimeToLive ofHours(long hours)
      Creates a duration using a period of hours.
      Parameters:
      hours - the number of hours in the duration, must be a non-negative number
      Returns:
      the duration
      Throws:
      IllegalArgumentException - if a negative value is provided

    • ofDays

      public static TimeToLive ofDays(long days)
      Creates a duration using a period of 24 hour days.
      Parameters:
      days - the number of days in the duration, must be a non-negative number
      Returns:
      the duration
      Throws:
      IllegalArgumentException - if a negative value is provided

    • toDays

      public long toDays()
      Returns the number of days in this duration, which may be negative.
      Returns:
      the number of days

    • toHours

      public long toHours()
      Returns the number of hours in this duration, which may be negative.
      Returns:
      the number of hours

    • toExpirationTime

      public long toExpirationTime(long referenceTime)
      Returns an absolute time representing the duration plus the absolute time reference parameter. If an expiration time from the current time is desired the parameter should be System.currentTimeMillis(). If the duration of this object is 0 (DO_NOT_EXPIRE), indicating no expiration time, this method will return 0, regardless of the reference time.
      Parameters:
      referenceTime - an absolute time in milliseconds since January 1, 1970.
      Returns:
      time in milliseconds, 0 if this object's duration is 0

    • fromExpirationTime

      public static TimeToLive fromExpirationTime(long expirationTime, long referenceTime)
      Returns an instance of TimeToLive based on an absolute expiration time and a reference time. If a duration relative to the current time is desired the referenceTime should be System.currentTimeMillis(). If the expirationTime is 0, the referenceTime is ignored and a TimeToLive of duration 0 is created, indicating no expiration.

      Days will be use as the primary unit of duration if the expiration time is evenly divisible into days, otherwise hours are used.

      Parameters:
      expirationTime - an absolute time in milliseconds since January 1, 1970
      referenceTime - an absolute time in milliseconds since January 1, 1970.
      Returns:
      a TimeToLive instance

    • equals

      public boolean equals(Object other)
      Equality compares the duration only if the units used for construction are the same. If the units (ofHours vs ofDays) are different two instances will not be equal even if their absolute durations are the same unless both values are 0, which means no expiration.
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • convertTimeToLiveUnit

      public static TimeUnit convertTimeToLiveUnit(int ttlVal, byte unitOrdinal)
      Converts an ordinal value for a TTL TimeUnit into the TimeUnit.

    • getTTLValue

      public static int getTTLValue(TimeToLive ttl)
      Returns the numeric duration value associated with a TimeToLive, or 0 if the ttl is null.
      Parameters:
      ttl - the ttl or null
      Returns:
      the numeric duration value

    • getTTLUnit

      public static TimeUnit getTTLUnit(TimeToLive ttl)
      Returns the TimeUnit associated with a TimeToLive, or {TimeUnit#DAYS} if the ttl is null.
      Parameters:
      ttl - the ttl or null
      Returns:
      the time unit