Package org.apache.cassandra.db.lifecycle

Class View

java.lang.Object

org.apache.cassandra.db.lifecycle.View

public class View
extends java.lang.Object

An immutable structure holding the current memtable, the memtables pending flush, the sstables for a column family, and the sstables that are active in compaction (a subset of the sstables). Modifications to instances are all performed via a Function produced by the static methods in this class. These are composed as necessary and provided to the Tracker.apply() methods, which atomically reject or accept and apply the changes to the View.

Field Summary

Fields

Modifier and Type	Field	Description
java.util.List<Memtable>	flushingMemtables	contains all memtables that are no longer referenced for writing and are queued for / in the process of being flushed.
java.util.List<Memtable>	liveMemtables	ordinarily a list of size 1, but when preparing to flush will contain both the memtable we will flush and the new replacement memtable, until all outstanding write operations on the old table complete.

Method Summary

Modifier and Type	Method	Description
java.lang.Iterable<SSTableReader>	allKnownSSTables()
java.lang.Iterable<Memtable>	getAllMemtables()
Memtable	getCurrentMemtable()
java.lang.Iterable<SSTableReader>	getUncompacting(java.lang.Iterable<SSTableReader> candidates)
boolean	isEmpty()
java.util.Set<SSTableReader>	liveSSTables()
java.lang.Iterable<SSTableReader>	liveSSTablesInBounds(PartitionPosition left, PartitionPosition right)	Returns the sstables that have any partition between left and right, when both bounds are taken inclusively.
java.lang.Iterable<SSTableReader>	select(SSTableSet sstableSet)
static com.google.common.base.Function<View,java.lang.Iterable<SSTableReader>>	select(SSTableSet sstableSet, com.google.common.base.Predicate<SSTableReader> filter)
static com.google.common.base.Function<View,java.lang.Iterable<SSTableReader>>	select(SSTableSet sstableSet, DecoratedKey key)
static com.google.common.base.Function<View,java.lang.Iterable<SSTableReader>>	selectFunction(SSTableSet sstableSet)
static com.google.common.base.Function<View,java.lang.Iterable<SSTableReader>>	selectLive(AbstractBounds<PartitionPosition> rowBounds)
java.lang.Iterable<SSTableReader>	sstables(SSTableSet sstableSet, com.google.common.base.Predicate<SSTableReader> filter)
static java.util.List<SSTableReader>	sstablesInBounds(PartitionPosition left, PartitionPosition right, SSTableIntervalTree intervalTree)
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

liveMemtables

public final java.util.List<Memtable> liveMemtables

ordinarily a list of size 1, but when preparing to flush will contain both the memtable we will flush and the new replacement memtable, until all outstanding write operations on the old table complete. The last item in the list is always the "current" memtable.

flushingMemtables

public final java.util.List<Memtable> flushingMemtables

contains all memtables that are no longer referenced for writing and are queued for / in the process of being flushed. In chronologically ascending order.

Method Detail

getCurrentMemtable

public Memtable getCurrentMemtable()

getAllMemtables

public java.lang.Iterable<Memtable> getAllMemtables()

Returns:

the active memtable and all the memtables that are pending flush.

liveSSTables

public java.util.Set<SSTableReader> liveSSTables()

sstables

public java.lang.Iterable<SSTableReader> sstables(SSTableSet sstableSet,
                                                  com.google.common.base.Predicate<SSTableReader> filter)

allKnownSSTables

public java.lang.Iterable<SSTableReader> allKnownSSTables()

select

public java.lang.Iterable<SSTableReader> select(SSTableSet sstableSet)

getUncompacting

public java.lang.Iterable<SSTableReader> getUncompacting(java.lang.Iterable<SSTableReader> candidates)

isEmpty

public boolean isEmpty()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

liveSSTablesInBounds

public java.lang.Iterable<SSTableReader> liveSSTablesInBounds(PartitionPosition left,
                                                              PartitionPosition right)

Returns the sstables that have any partition between left and right, when both bounds are taken inclusively. The interval formed by left and right shouldn't wrap.

sstablesInBounds

public static java.util.List<SSTableReader> sstablesInBounds(PartitionPosition left,
                                                             PartitionPosition right,
                                                             SSTableIntervalTree intervalTree)

selectFunction

public static com.google.common.base.Function<View,java.lang.Iterable<SSTableReader>> selectFunction(SSTableSet sstableSet)

select

public static com.google.common.base.Function<View,java.lang.Iterable<SSTableReader>> select(SSTableSet sstableSet,
                                                                                                   com.google.common.base.Predicate<SSTableReader> filter)

select

public static com.google.common.base.Function<View,java.lang.Iterable<SSTableReader>> select(SSTableSet sstableSet,
                                                                                                   DecoratedKey key)

Returns:

a ViewFragment containing the sstables and memtables that may need to be merged for the given @param key, according to the interval tree

selectLive

public static com.google.common.base.Function<View,java.lang.Iterable<SSTableReader>> selectLive(AbstractBounds<PartitionPosition> rowBounds)

Returns:

a ViewFragment containing the sstables and memtables that may need to be merged for rows within @param rowBounds, inclusive, according to the interval tree.