mondrian.rolap
Class SmartMemberReader

java.lang.Object
  mondrian.rolap.SmartMemberReader

All Implemented Interfaces:

MemberReader, MemberSource

Direct Known Subclasses:

RolapCubeHierarchy.CacheRolapCubeHierarchyMemberReader

public class SmartMemberReader
extends Object
implements MemberReader

SmartMemberReader implements MemberReader by keeping a cache of members and their children. If a member is 'in cache', there is a list of its children. It also caches the members of levels.

Synchronization: the MemberReader source must be called from synchronized(this) context - it does not synchronize itself (probably it should).

Constraints: Member.Children and Level.Members may be constrained by a SqlConstraint object. In this case a subset of all members is returned. These subsets are cached too and the SqlConstraint is part of the cache key. This is used in NON EMPTY context.

Uniqueness. We need to ensure that there is never more than one RolapMember object representing the same member.

Since:

21 December, 2001

Author:

jhyde

Nested Class Summary

(package private) class

SmartMemberReader.SiblingIterator SiblingIterator helps traverse a hierarchy of members, by remembering the position at each level.

Field Summary

protected MemberCacheHelper	cacheHelper
protected List<RolapMember>	rootMembers
protected MemberReader	source access to source must be synchronized(this)

Constructor Summary

SmartMemberReader(MemberReader source)

Method Summary

protected void	checkCacheStatus()
int	compare(RolapMember m1, RolapMember m2, boolean siblingsAreEqual) Compares two members according to their order in a prefix ordered traversal.
RolapMember	desubstitute(RolapMember member) Returns the member which was substituted.
RolapMember	getDefaultMember()
RolapHierarchy	getHierarchy() Returns the hierarchy that this source is reading for.
RolapMember	getLeadMember(RolapMember member, int n) Returns the member n after member in the same level (or before, if n is negative).
int	getLevelMemberCount(RolapLevel level) Returns the number of members in this level.
TupleReader.MemberBuilder	getMemberBuilder()
MemberCache	getMemberCache()
void	getMemberChildren(List<RolapMember> parentMembers, List<RolapMember> children) Returns all members which are a child of one of the members in parentMembers, sorted by ordinal.
void	getMemberChildren(List<RolapMember> parentMembers, List<RolapMember> children, MemberChildrenConstraint constraint) Populates a list of the children of a given set of Members, optionally applying a constraint.
void	getMemberChildren(RolapMember parentMember, List<RolapMember> children) Writes all children parentMember to children.
void	getMemberChildren(RolapMember parentMember, List<RolapMember> children, MemberChildrenConstraint constraint) Populates a list of the children of a Member, optionally applying a constraint.
int	getMemberCount() Returns an estimate of number of members in this hierarchy.
RolapMember	getMemberParent(RolapMember member)
void	getMemberRange(RolapLevel level, RolapMember startMember, RolapMember endMember, List<RolapMember> list) Writes all members between startMember and endMember into list.
List<RolapMember>	getMembers() Returns all members of this hierarchy, sorted by ordinal.
List<RolapMember>	getMembersInLevel(RolapLevel level, int startOrdinal, int endOrdinal) Returns all of the members in level whose ordinal lies between startOrdinal and endOrdinal.
List<RolapMember>	getMembersInLevel(RolapLevel level, int startOrdinal, int endOrdinal, TupleConstraint constraint) Returns the members in the given Level, optionally between a range of ordinals and applying a constraint.
List<RolapMember>	getRootMembers() Returns all members of this hierarchy which do not have a parent, sorted by ordinal.
boolean	isSorted(List<RolapMember> members) Returns true if every element of members is not null and is strictly less than the following element; false otherwise.
RolapMember	lookupMember(List<Id.Segment> uniqueNameParts, boolean failIfNotFound) Finds a member based upon its unique name.
protected void	readMemberChildren(List<RolapMember> members, List<RolapMember> result, MemberChildrenConstraint constraint) Reads the children of member into cache, and also into result.
boolean	setCache(MemberCache cache) Sets the cache which this MemberSource will write to.
RolapMember	substitute(RolapMember member) Substitutes a given member.

Methods inherited from class java.lang.Object

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

Field Detail

source

protected final MemberReader source

access to source must be synchronized(this)

cacheHelper

protected final MemberCacheHelper cacheHelper

rootMembers

protected List<RolapMember> rootMembers

Constructor Detail

SmartMemberReader

SmartMemberReader(MemberReader source)

Method Detail

getHierarchy

public RolapHierarchy getHierarchy()

Description copied from interface: MemberSource

Returns the hierarchy that this source is reading for.

Specified by:

getHierarchy in interface MemberSource

getMemberCache

public MemberCache getMemberCache()

setCache

public boolean setCache(MemberCache cache)

Description copied from interface: MemberSource

Sets the cache which this MemberSource will write to.

Cache-writeback is optional (for example, SqlMemberSource supports it, and ArrayMemberSource does not), and the return value from this method indicates whether this object supports it.

If this method returns true, the MemberSource.getMembers(), MemberSource.getRootMembers() and MemberSource.getMemberChildren(mondrian.rolap.RolapMember, java.util.List) methods must write to the cache, in addition to returning members as a return value.

Specified by:

setCache in interface MemberSource

Parameters:

cache - The MemberCache which the caller would like this MemberSource to write to.

Returns:

Whether this MemberSource supports cache-writeback.

substitute

public RolapMember substitute(RolapMember member)

Description copied from interface: MemberReader

Substitutes a given member. If member is null, returns null.

This method is called whenever a member is returned from the wrapped member reader and is to be returned to the caller. You could say that it translates 'to caller space'.

Specified by:

substitute in interface MemberReader

Parameters:

member - Member

Returns:

Substitute member

desubstitute

public RolapMember desubstitute(RolapMember member)

Description copied from interface: MemberReader

Returns the member which was substituted. If member is null, returns null.

This method is called whenever the caller passes a member into a method and needs to be passed to a method on the wrapped member reader. You could say that it translates 'from caller space'.

Specified by:

desubstitute in interface MemberReader

Parameters:

member - Member

Returns:

Internal member

getMembers

public List<RolapMember> getMembers()

Description copied from interface: MemberSource

Returns all members of this hierarchy, sorted by ordinal.

If this object supports cache-writeaback, also writes these members to the cache.

Specified by:

getMembers in interface MemberSource

getRootMembers

public List<RolapMember> getRootMembers()

Description copied from interface: MemberSource

Returns all members of this hierarchy which do not have a parent, sorted by ordinal.

If this object supports cache-writeback, also writes these members to the cache.

Specified by:

getRootMembers in interface MemberSource

Returns:

List of RolapMembers

getMembersInLevel

public List<RolapMember> getMembersInLevel(RolapLevel level,
                                           int startOrdinal,
                                           int endOrdinal)

Description copied from interface: MemberReader

Returns all of the members in level whose ordinal lies between startOrdinal and endOrdinal.

If this object supports cache-writeback, also writes these members to the cache.

Specified by:

getMembersInLevel in interface MemberReader

Returns:

List of RolapMember

checkCacheStatus

protected void checkCacheStatus()

getMembersInLevel

public List<RolapMember> getMembersInLevel(RolapLevel level,
                                           int startOrdinal,
                                           int endOrdinal,
                                           TupleConstraint constraint)

Description copied from interface: MemberReader

Returns the members in the given Level, optionally between a range of ordinals and applying a constraint.

Specified by:

getMembersInLevel in interface MemberReader

Parameters:

level - Level

startOrdinal - Ordinal of first member to retrieve

endOrdinal - Ordinal of last member to upper bound

constraint - Constraint

Returns:

list of members

getLevelMemberCount

public int getLevelMemberCount(RolapLevel level)

Description copied from interface: MemberReader

Returns the number of members in this level.

Specified by:

getLevelMemberCount in interface MemberReader

Parameters:

level - Level

Returns:

number of members in level

getMemberChildren

public void getMemberChildren(RolapMember parentMember,
                              List<RolapMember> children)

Description copied from interface: MemberSource

Writes all children parentMember to children.

If this object supports cache-writeback, also writes these members to the cache.

Specified by:

getMemberChildren in interface MemberSource

getMemberChildren

public void getMemberChildren(RolapMember parentMember,
                              List<RolapMember> children,
                              MemberChildrenConstraint constraint)

Description copied from interface: MemberReader

Populates a list of the children of a Member, optionally applying a constraint.

Specified by:

getMemberChildren in interface MemberReader

Parameters:

parentMember - Members whose children to find

children - List to populate with members

constraint - Constraint

getMemberChildren

public void getMemberChildren(List<RolapMember> parentMembers,
                              List<RolapMember> children)

Description copied from interface: MemberSource

Returns all members which are a child of one of the members in parentMembers, sorted by ordinal.

If this object supports cache-writeaback, also writes these members to the cache.

Specified by:

getMemberChildren in interface MemberSource

getMemberChildren

public void getMemberChildren(List<RolapMember> parentMembers,
                              List<RolapMember> children,
                              MemberChildrenConstraint constraint)

Description copied from interface: MemberReader

Populates a list of the children of a given set of Members, optionally applying a constraint.

Specified by:

getMemberChildren in interface MemberReader

Parameters:

parentMembers - List of members whose children to find

children - List to populate with members

constraint - Constraint

lookupMember

public RolapMember lookupMember(List<Id.Segment> uniqueNameParts,
                                boolean failIfNotFound)

Description copied from interface: MemberSource

Finds a member based upon its unique name.

Specified by:

lookupMember in interface MemberSource

readMemberChildren

protected void readMemberChildren(List<RolapMember> members,
                                  List<RolapMember> result,
                                  MemberChildrenConstraint constraint)

Reads the children of member into cache, and also into result.

Parameters:

result - Children are written here, in order

members - Members whose children to read

constraint - restricts the returned members if possible (optional optimization)

isSorted

public boolean isSorted(List<RolapMember> members)

Returns true if every element of members is not null and is strictly less than the following element; false otherwise.

getLeadMember

public RolapMember getLeadMember(RolapMember member,
                                 int n)

Description copied from interface: MemberReader

Returns the member n after member in the same level (or before, if n is negative). Returns Hierarchy.getNullMember() if we run off the beginning or end of the level.

Specified by:

getLeadMember in interface MemberReader

getMemberRange

public void getMemberRange(RolapLevel level,
                           RolapMember startMember,
                           RolapMember endMember,
                           List<RolapMember> list)

Description copied from interface: MemberReader

Writes all members between startMember and endMember into list.

Specified by:

getMemberRange in interface MemberReader

getMemberCount

public int getMemberCount()

Description copied from interface: MemberSource

Returns an estimate of number of members in this hierarchy.

Specified by:

getMemberCount in interface MemberSource

compare

public int compare(RolapMember m1,
                   RolapMember m2,
                   boolean siblingsAreEqual)

Description copied from interface: MemberReader

Compares two members according to their order in a prefix ordered traversal. If siblingsAreEqual, then two members with the same parent will compare equal.

Specified by:

compare in interface MemberReader

Returns:

less than zero if m1 occurs before m2, greater than zero if m1 occurs after m2, zero if m1 is equal to m2, or if siblingsAreEqual and m1 and m2 have the same parent

getMemberBuilder

public TupleReader.MemberBuilder getMemberBuilder()

Specified by:

getMemberBuilder in interface MemberReader

getDefaultMember

public RolapMember getDefaultMember()

Specified by:

getDefaultMember in interface MemberReader

getMemberParent

public RolapMember getMemberParent(RolapMember member)

Specified by:

getMemberParent in interface MemberReader