org.apache.cassandra.db

Class PartitionRangeReadCommand

java.lang.Object

org.apache.cassandra.db.monitoring.MonitorableImpl

org.apache.cassandra.db.ReadCommand

org.apache.cassandra.db.PartitionRangeReadCommand

All Implemented Interfaces:

Monitorable, PartitionRangeReadQuery, ReadQuery

public class PartitionRangeReadCommand
extends ReadCommand
implements PartitionRangeReadQuery

A read command that selects a (part of a) range of partitions.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.cassandra.db.ReadCommand

ReadCommand.CheckForAbort, ReadCommand.Kind, ReadCommand.SelectionDeserializer, ReadCommand.Serializer

Field Summary

Fields

Modifier and Type	Field and Description
protected static ReadCommand.SelectionDeserializer	selectionDeserializer

Fields inherited from class org.apache.cassandra.db.ReadCommand

logger, serializer

Method Summary

Modifier and Type	Method and Description
static PartitionRangeReadCommand	allDataRead(TableMetadata metadata, int nowInSec) Creates a new read command that query all the data in the table.
protected void	appendCQLWhereClause(java.lang.StringBuilder sb)
ClusteringIndexFilter	clusteringIndexFilter(DecoratedKey key) The clustering index filter this command to use for the provided key.
ColumnFilter	columnFilter() A filter on which (non-PK) columns must be returned by the query.
PartitionRangeReadCommand	copy() Returns a copy of this command.
protected PartitionRangeReadCommand	copyAsDigestQuery()
protected PartitionRangeReadCommand	copyAsTransientQuery()
static PartitionRangeReadCommand	create(TableMetadata metadata, int nowInSec, ColumnFilter columnFilter, RowFilter rowFilter, DataLimits limits, DataRange dataRange)
DataRange	dataRange()
PartitionIterator	execute(ConsistencyLevel consistency, ClientState clientState, long queryStartNanoTime) Executes the query at the provided consistency level.
PartitionIterator	executeInternal(ReadExecutionController controller) Execute the query for internal queries (that is, it basically executes the query locally).
PartitionRangeReadCommand	forSubRange(AbstractBounds<PartitionPosition> range, boolean isRangeContinuation) Returns an equivalent command but that only queries data within the provided range.
long	getTimeout(java.util.concurrent.TimeUnit unit) The configured timeout for this command.
boolean	isLimitedToOnePartition()
boolean	isNamesQuery()
boolean	isRangeRequest()
boolean	isReversed() Whether the underlying ClusteringIndexFilter is reversed or not.
DataLimits	limits() The limits for the query.
TableMetadata	metadata() The metadata for the table this is a query on.
int	nowInSec() The time in seconds to use as "now" for this query.
PartitionIterator	postReconciliationProcessing(PartitionIterator result) Allow to post-process the result of the query after it has been reconciled on the coordinator but before it is passed to the CQL layer to return the ResultSet.
UnfilteredPartitionIterator	queryStorage(ColumnFamilyStore cfs, ReadExecutionController executionController)
protected void	recordLatency(TableMetrics metric, long latencyNanos)
RowFilter	rowFilter() Filters/Resrictions on CQL rows.
protected long	selectionSerializedSize(int version)
protected void	serializeSelection(DataOutputPlus out, int version)
java.lang.String	toString()
Verb	verb()
PartitionRangeReadCommand	withUpdatedLimit(DataLimits newLimits) Creates a new ReadCommand instance with new limits.
PartitionRangeReadCommand	withUpdatedLimitsAndDataRange(DataLimits newLimits, DataRange newDataRange) Creates a new PartitionRangeReadQuery with the updated limits and data range.

Methods inherited from class org.apache.cassandra.db.ReadCommand

acceptsTransient, copyAsDigestQuery, copyAsDigestQuery, copyAsTransientQuery, copyAsTransientQuery, createMessage, createResponse, digestVersion, executeLocally, executionController, getIndex, getRepairedDataDigest, indexMetadata, isDigestQuery, isRepairedDataDigestConclusive, isTrackingRepairedStatus, maybeValidateIndex, name, oldestUnrepairedTombstone, setDigestVersion, toCQLString, trackRepairedStatus, withoutPurgeableTombstones, withStateTracking

Methods inherited from class org.apache.cassandra.db.monitoring.MonitorableImpl

abort, complete, creationTimeNanos, isAborted, isCompleted, isCrossNode, isInProgress, isSlow, setMonitoringTime, slowTimeoutNanos, timeoutNanos

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.cassandra.db.PartitionRangeReadQuery

getPager, selectsClustering, selectsFullPartition, selectsKey

Methods inherited from interface org.apache.cassandra.db.ReadQuery

columnFilter, empty, executeInternal, executeLocally, executionController, isEmpty, limits, maybeValidateIndex, metadata, nowInSec, rowFilter

Field Detail

selectionDeserializer

protected static final ReadCommand.SelectionDeserializer selectionDeserializer

Method Detail

create

public static PartitionRangeReadCommand create(TableMetadata metadata,
                                               int nowInSec,
                                               ColumnFilter columnFilter,
                                               RowFilter rowFilter,
                                               DataLimits limits,
                                               DataRange dataRange)

Specified by:

create in interface PartitionRangeReadQuery

allDataRead

public static PartitionRangeReadCommand allDataRead(TableMetadata metadata,
                                                    int nowInSec)

Creates a new read command that query all the data in the table.

Parameters:

metadata - the table to query.

nowInSec - the time in seconds to use are "now" for this query.

Returns:

a newly created read command that queries everything in the table.

dataRange

public DataRange dataRange()

Specified by:

dataRange in interface PartitionRangeReadQuery

clusteringIndexFilter

public ClusteringIndexFilter clusteringIndexFilter(DecoratedKey key)

Description copied from class: ReadCommand

The clustering index filter this command to use for the provided key.

Note that that method should only be called on a key actually queried by this command and in practice, this will almost always return the same filter, but for the sake of paging, the filter on the first key of a range command might be slightly different.

Specified by:

clusteringIndexFilter in class ReadCommand

Parameters:

key - a partition key queried by this command.

Returns:

the ClusteringIndexFilter to use for the partition of key key.

isNamesQuery

public boolean isNamesQuery()

forSubRange

public PartitionRangeReadCommand forSubRange(AbstractBounds<PartitionPosition> range,
                                             boolean isRangeContinuation)

Returns an equivalent command but that only queries data within the provided range.

Parameters:

range - the sub-range to restrict the command to. This method assumes that this is a proper sub-range of the command this is applied to.

isRangeContinuation - whether range is a direct continuation of whatever previous range we have queried. This matters for the DataLimits that may contain states when we do paging and in the context of parallel queries: that state only make sense if the range queried is indeed the follow-up of whatever range we've previously query (that yield said state). In practice this means that ranges for which isRangeContinuation is false may have to be slightly pessimistic when counting data and may include a little bit than necessary, and this should be dealt with post-query (in the case of StorageProxy.getRangeSlice(), which uses this method for replica queries, this is dealt with by re-counting results on the coordinator). Note that if this is the first range we queried, then the DataLimits will have not state and the value of this parameter doesn't matter.

copy

public PartitionRangeReadCommand copy()

Description copied from class: ReadCommand

Returns a copy of this command.

Specified by:

copy in class ReadCommand

Returns:

a copy of this command.

copyAsDigestQuery

protected PartitionRangeReadCommand copyAsDigestQuery()

Specified by:

copyAsDigestQuery in class ReadCommand

copyAsTransientQuery

protected PartitionRangeReadCommand copyAsTransientQuery()

Specified by:

copyAsTransientQuery in class ReadCommand

withUpdatedLimit

public PartitionRangeReadCommand withUpdatedLimit(DataLimits newLimits)

Description copied from class: ReadCommand

Creates a new ReadCommand instance with new limits.

Specified by:

withUpdatedLimit in interface PartitionRangeReadQuery

Specified by:

withUpdatedLimit in class ReadCommand

Parameters:

newLimits - the new limits

Returns:

a new ReadCommand with the updated limits

withUpdatedLimitsAndDataRange

public PartitionRangeReadCommand withUpdatedLimitsAndDataRange(DataLimits newLimits,
                                                               DataRange newDataRange)

Description copied from interface: PartitionRangeReadQuery

Creates a new PartitionRangeReadQuery with the updated limits and data range.

Specified by:

withUpdatedLimitsAndDataRange in interface PartitionRangeReadQuery

Parameters:

newLimits - the new limits

Returns:

the new PartitionRangeReadQuery

getTimeout

public long getTimeout(java.util.concurrent.TimeUnit unit)

Description copied from class: ReadCommand

The configured timeout for this command.

Specified by:

getTimeout in class ReadCommand

Returns:

the configured timeout for this command.

isReversed

public boolean isReversed()

Description copied from class: ReadCommand

Whether the underlying ClusteringIndexFilter is reversed or not.

Specified by:

isReversed in class ReadCommand

Returns:

whether the underlying ClusteringIndexFilter is reversed or not.

execute

public PartitionIterator execute(ConsistencyLevel consistency,
                                 ClientState clientState,
                                 long queryStartNanoTime)
                          throws RequestExecutionException

Description copied from interface: ReadQuery

Executes the query at the provided consistency level.

Specified by:

execute in interface ReadQuery

Parameters:

consistency - the consistency level to achieve for the query.

clientState - the ClientState for the query. In practice, this can be null unless consistency is a serial consistency.

Returns:

the result of the query.

Throws:

RequestExecutionException

recordLatency

protected void recordLatency(TableMetrics metric,
                             long latencyNanos)

Specified by:

recordLatency in class ReadCommand

queryStorage

public UnfilteredPartitionIterator queryStorage(ColumnFamilyStore cfs,
                                                ReadExecutionController executionController)

Specified by:

queryStorage in class ReadCommand

verb

public Verb verb()

Specified by:

verb in class ReadCommand

appendCQLWhereClause

protected void appendCQLWhereClause(java.lang.StringBuilder sb)

Specified by:

appendCQLWhereClause in class ReadCommand

postReconciliationProcessing

public PartitionIterator postReconciliationProcessing(PartitionIterator result)

Allow to post-process the result of the query after it has been reconciled on the coordinator but before it is passed to the CQL layer to return the ResultSet. See CASSANDRA-8717 for why this exists.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

serializeSelection

protected void serializeSelection(DataOutputPlus out,
                                  int version)
                           throws java.io.IOException

Specified by:

serializeSelection in class ReadCommand

Throws:

java.io.IOException

selectionSerializedSize

protected long selectionSerializedSize(int version)

Specified by:

selectionSerializedSize in class ReadCommand

isLimitedToOnePartition

public boolean isLimitedToOnePartition()

Specified by:

isLimitedToOnePartition in class ReadCommand

isRangeRequest

public boolean isRangeRequest()

Specified by:

isRangeRequest in class ReadCommand

metadata

public TableMetadata metadata()

Description copied from interface: ReadQuery

The metadata for the table this is a query on.

Specified by:

metadata in interface ReadQuery

Returns:

the metadata for the table this is a query on.

executeInternal

public PartitionIterator executeInternal(ReadExecutionController controller)

Description copied from interface: ReadQuery

Execute the query for internal queries (that is, it basically executes the query locally).

Specified by:

executeInternal in interface ReadQuery

Parameters:

controller - the ReadExecutionController protecting the read.

Returns:

the result of the query.

limits

public DataLimits limits()

Description copied from interface: ReadQuery

The limits for the query.

Specified by:

limits in interface ReadQuery

Returns:

The limits for the query.

nowInSec

public int nowInSec()

Description copied from interface: ReadQuery

The time in seconds to use as "now" for this query.

We use the same time as "now" for the whole query to avoid considering different values as expired during the query, which would be buggy (would throw of counting amongst other things).

Specified by:

nowInSec in interface ReadQuery

Returns:

the time (in seconds) to use as "now".

rowFilter

public RowFilter rowFilter()

Description copied from interface: ReadQuery

Filters/Resrictions on CQL rows.

This contains the restrictions that are not directly handled by the ClusteringIndexFilter. More specifically, this includes any non-PK column restrictions and can include some PK columns restrictions when those can't be satisfied entirely by the clustering index filter (because not all clustering columns have been restricted for instance). If there is 2ndary indexes on the table, one of this restriction might be handled by a 2ndary index.

Specified by:

rowFilter in interface ReadQuery

Returns:

the filter holding the expression that rows must satisfy.

columnFilter

public ColumnFilter columnFilter()

Description copied from interface: ReadQuery

A filter on which (non-PK) columns must be returned by the query.

Specified by:

columnFilter in interface ReadQuery

Returns:

which columns must be fetched by this query.