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 and 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 and 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()
static com.google.common.base.Function<View,java.lang.Iterable<SSTableReader>>	select(SSTableSet sstableSet)
static com.google.common.base.Function<View,java.lang.Iterable<SSTableReader>>	select(SSTableSet sstableSet, AbstractBounds<PartitionPosition> rowBounds)
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>>	select(SSTableSet sstableSet, com.google.common.base.Predicate<SSTableReader> filter)
java.lang.Iterable<SSTableReader>	sstables(SSTableSet sstableSet)
java.lang.Iterable<SSTableReader>	sstables(SSTableSet sstableSet, com.google.common.base.Predicate<SSTableReader> filter)
java.lang.Iterable<SSTableReader>	sstablesInBounds(SSTableSet sstableSet, AbstractBounds<PartitionPosition> rowBounds)
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)

sstables

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

allKnownSSTables

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

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

sstablesInBounds

public java.lang.Iterable<SSTableReader> sstablesInBounds(SSTableSet sstableSet,
                                                          AbstractBounds<PartitionPosition> rowBounds)

select

public static com.google.common.base.Function<View,java.lang.Iterable<SSTableReader>> select(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

select

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