mondrian.rolap.cache

Interface SegmentCacheIndex

All Known Implementing Classes:

SegmentCacheIndexImpl

public interface SegmentCacheIndex

Data structure that identifies which segments contain cells.

Not thread-safe.

Author:

Julian Hyde

Method Summary

Modifier and Type	Method and Description
void	add(SegmentHeader header, SegmentBuilder.SegmentConverter converter, boolean loading) Adds a header to the index.
void	cancel(Execution exec) This method must remove all registrations as a client for the given execution.
boolean	contains(SegmentHeader header) Tells whether or not a given segment is known to this index.
List<List<SegmentHeader>>	findRollupCandidates(String schemaName, ByteString schemaChecksum, String cubeName, String measureName, String rolapStarFactTableName, BitKey constrainedColsBitKey, Map<String,Comparable> coordinates, List<String> compoundPredicates) Returns a list of segments that can be rolled up to satisfy a given cell request.
SegmentBuilder.SegmentConverter	getConverter(String schemaName, ByteString schemaChecksum, String cubeName, String rolapStarFactTableName, String measureName, List<String> compoundPredicates) Returns a converter that can convert the given header to internal format.
Future<SegmentBody>	getFuture(Execution exec, SegmentHeader header) Returns a future slot for a segment body, if a segment is currently loading, otherwise null.
List<SegmentHeader>	intersectRegion(String schemaName, ByteString schemaChecksum, String cubeName, String measureName, String rolapStarFactTableName, SegmentColumn[] region) Finds a list of headers that intersect a given region.
void	linkSqlStatement(SegmentHeader header, Statement stmt) Allows to link a Statement to a segment.
void	loadFailed(SegmentHeader header, Throwable throwable) Notifies the segment index that a segment failed to load, and removes the segment from the index.
void	loadSucceeded(SegmentHeader header, SegmentBody body) Changes the state of a header from loading to loaded.
List<SegmentHeader>	locate(String schemaName, ByteString schemaChecksum, String cubeName, String measureName, String rolapStarFactTableName, BitKey constrainedColsBitKey, Map<String,Comparable> coordinates, List<String> compoundPredicates) Identifies the segment headers that contain a given cell.
void	printCacheState(PrintWriter pw) Prints the state of the cache to the given writer.
void	remove(SegmentHeader header) Removes a header from the index.
void	setConverter(String schemaName, ByteString schemaChecksum, String cubeName, String rolapStarFactTableName, String measureName, List<String> compoundPredicates, SegmentBuilder.SegmentConverter converter) Sets a converter that can convert headers in for a given measure to internal format.
void	update(SegmentHeader oldHeader, SegmentHeader newHeader) Updates a header in the index.

Method Detail

locate

List<SegmentHeader> locate(String schemaName,
                           ByteString schemaChecksum,
                           String cubeName,
                           String measureName,
                           String rolapStarFactTableName,
                           BitKey constrainedColsBitKey,
                           Map<String,Comparable> coordinates,
                           List<String> compoundPredicates)

Identifies the segment headers that contain a given cell.

Parameters:

schemaName - Schema name

schemaChecksum - Schema checksum

cubeName - Cube name

measureName - Measure name

rolapStarFactTableName - Fact table table

constrainedColsBitKey - Bit key

coordinates - Coordinates

compoundPredicates - Compound predicates

Returns:

Empty list if not found; never null

findRollupCandidates

List<List<SegmentHeader>> findRollupCandidates(String schemaName,
                                               ByteString schemaChecksum,
                                               String cubeName,
                                               String measureName,
                                               String rolapStarFactTableName,
                                               BitKey constrainedColsBitKey,
                                               Map<String,Comparable> coordinates,
                                               List<String> compoundPredicates)

Returns a list of segments that can be rolled up to satisfy a given cell request.

Parameters:

schemaName - Schema name

schemaChecksum - Schema checksum

cubeName - Cube name

measureName - Measure name

rolapStarFactTableName - Fact table table

constrainedColsBitKey - Bit key

coordinates - Coordinates

compoundPredicates - Compound predicates

Returns:

List of candidates; each element is a list of headers that, when combined using union, are sufficient to answer the given cell request

intersectRegion

List<SegmentHeader> intersectRegion(String schemaName,
                                    ByteString schemaChecksum,
                                    String cubeName,
                                    String measureName,
                                    String rolapStarFactTableName,
                                    SegmentColumn[] region)

Finds a list of headers that intersect a given region.

This method is used to find out which headers need to be trimmed or removed during a flush.

Parameters:

schemaName - Schema name

schemaChecksum - Schema checksum

cubeName - Cube name

measureName - Measure name

rolapStarFactTableName - Fact table table

region - Region

Returns:

List of intersecting headers

add

void add(SegmentHeader header,
         SegmentBuilder.SegmentConverter converter,
         boolean loading)

Adds a header to the index.

Parameters:

header - Segment header

loading - Whether segment is pending a load from SQL

converter - Segment converter

update

void update(SegmentHeader oldHeader,
            SegmentHeader newHeader)

Updates a header in the index. This is required when some of the excluded regions have changed.

Parameters:

oldHeader - The old header to replace.

newHeader - The new header to use instead.

loadSucceeded

void loadSucceeded(SegmentHeader header,
                   SegmentBody body)

Changes the state of a header from loading to loaded.

The segment must have previously been added by calling add(mondrian.spi.SegmentHeader, mondrian.rolap.agg.SegmentBuilder.SegmentConverter, boolean) with a not-null value of the bodyFuture parameter; neither loadSucceeded nor loadFailed(mondrian.spi.SegmentHeader, java.lang.Throwable) must have been called.

Informs anyone waiting on the future supplied with add(mondrian.spi.SegmentHeader, mondrian.rolap.agg.SegmentBuilder.SegmentConverter, boolean).

Parameters:

header - Segment header

body - Segment body

loadFailed

void loadFailed(SegmentHeader header,
                Throwable throwable)

Notifies the segment index that a segment failed to load, and removes the segment from the index.

The segment must have previously been added using add(mondrian.spi.SegmentHeader, mondrian.rolap.agg.SegmentBuilder.SegmentConverter, boolean) with a not-null value of the bodyFuture parameter; neither loadSucceeded(mondrian.spi.SegmentHeader, mondrian.spi.SegmentBody) nor loadFailed must have been called.

Informs anyone waiting on the future supplied with add(mondrian.spi.SegmentHeader, mondrian.rolap.agg.SegmentBuilder.SegmentConverter, boolean).

Parameters:

header - Header

throwable - Error message

remove

void remove(SegmentHeader header)

Removes a header from the index.

Parameters:

header - Segment header

printCacheState

void printCacheState(PrintWriter pw)

Prints the state of the cache to the given writer.

Parameters:

pw - Print writer

getFuture

Future<SegmentBody> getFuture(Execution exec,
                              SegmentHeader header)

Returns a future slot for a segment body, if a segment is currently loading, otherwise null. This is the method to use to get segments 'hot out of the oven'.

When this method is invoked, the execution instance of the thread is automatically added to the list of clients for the given segment. The calling code is responsible for calling cancel(Execution) when it is done with the segments, or else this registration will prevent others from canceling the running SQL statements associated to this segment.

Parameters:

header - Segment header

Returns:

Slot, or null

cancel

void cancel(Execution exec)

This method must remove all registrations as a client for the given execution. This must terminate all SQL activity for any orphaned segments.

Parameters:

exec - The execution to unregister.

contains

boolean contains(SegmentHeader header)

Tells whether or not a given segment is known to this index.

linkSqlStatement

void linkSqlStatement(SegmentHeader header,
                      Statement stmt)

Allows to link a Statement to a segment. This allows the index to cleanup when cancel(Execution) is invoked and orphaned segments are left.

Parameters:

header - The segment.

stmt - The SQL statement.

getConverter

SegmentBuilder.SegmentConverter getConverter(String schemaName,
                                             ByteString schemaChecksum,
                                             String cubeName,
                                             String rolapStarFactTableName,
                                             String measureName,
                                             List<String> compoundPredicates)

Returns a converter that can convert the given header to internal format.

Parameters:

schemaName - Schema name

schemaChecksum - Schema checksum

cubeName - Cube name

rolapStarFactTableName - Fact table

measureName - Measure name

compoundPredicates - Compound predicates

Returns:

Converter

setConverter

void setConverter(String schemaName,
                  ByteString schemaChecksum,
                  String cubeName,
                  String rolapStarFactTableName,
                  String measureName,
                  List<String> compoundPredicates,
                  SegmentBuilder.SegmentConverter converter)

Sets a converter that can convert headers in for a given measure to internal format.

Parameters:

schemaName - Schema name

schemaChecksum - Schema checksum

cubeName - Cube name

rolapStarFactTableName - Fact table

measureName - Measure name

compoundPredicates - Compound predicates

converter - Converter to store