Evaluator (Pentaho Community Edition Project: mondrian 8.2.0.1-349 API)

All Known Implementing Classes:

RolapDependencyTestingEvaluator, RolapEvaluator, RolapProfilingEvaluator
```
public interface Evaluator
```
An Evaluator holds the context necessary to evaluate an expression.

Since:

27 July, 2001

Author:

jhyde

Nested Class Summary

Nested Classes
Modifier and Type	Interface and Description
`static interface`	`Evaluator.NamedSetEvaluator` Interface for evaluating a particular named set.
`static interface`	`Evaluator.SetEvaluator` Interface for generically evaluating a set.

Method Summary

All Methods Instance Methods Abstract Methods Deprecated Methods
Modifier and Type	Method and Description
`boolean`	`currentIsEmpty()` Returns whether the current context is an empty cell.
`Object`	`evaluateCurrent()` Calculates and returns the value of the cell at the current context.
`String`	`format(Object o)` Formats a value as a string according to the current context's format.
`String`	`format(Object o, String formatString)` Formats a value as a string according to the current context's format, using a given format string.
`Object`	`getCachedResult(ExpCacheDescriptor key)` Simple caching of the result of an `Exp`.
`Locale`	`getConnectionLocale()` Returns the connection's locale.
`Member`	`getContext(Hierarchy hierarchy)`
`Cube`	`getCube()` Returns the current cube.
`int`	`getDepth()` Deprecated. Will be removed in mondrian-4
`String`	`getFormatString()` Returns the format string for this cell.
`int`	`getIterationLength()`
`Cube`	`getMeasureCube()` Returns the base (non-virtual) cube that the current measure in the context belongs to.
`Member[]`	`getMembers()` Returns an array of the members which make up the current context.
`int`	`getMissCount()` Returns the number of times that this evaluator has told a lie when retrieving cell values.
`Evaluator.NamedSetEvaluator`	`getNamedSetEvaluator(NamedSet namedSet, boolean create)` Returns an evaluator for a named set.
`Member[]`	`getNonAllMembers()` Returns an array of the non-All members which make up the current context.
`Object`	`getParameterValue(ParameterSlot slot)` Returns the value of a parameter, evaluating its default value if it is not set.
`Evaluator`	`getParent()` Deprecated. Will be removed in mondrian-4
`Member`	`getPreviousContext(Hierarchy hierarchy)` Returns the member that was the current evaluation context for a particular hierarchy before the most recent change in context.
`Object`	`getProperty(String name, Object defaultValue)` Retrieves the value of property `name`.
`Query`	`getQuery()` Returns the current query.
`Date`	`getQueryStartTime()` Returns the start time of the current query.
`SchemaReader`	`getSchemaReader()` Returns a `SchemaReader` appropriate for the current access-control context.
`Evaluator.SetEvaluator`	`getSetEvaluator(Exp exp, boolean create)` Returns an evaluator for a set.
`QueryTiming`	`getTiming()` Returns the query timing context for this execution.
`boolean`	`isEvalAxes()`
`boolean`	`isNonEmpty()` Returns true for an axis that is NON EMPTY.
`boolean`	`mightReturnNullForUnrelatedDimension()` Returns whether it is necessary to check whether to return null for an unrelated dimension.
`boolean`	`nativeEnabled()` Returns whether native evaluation is enabled in this context.
`boolean`	`needToReturnNullForUnrelatedDimension(Member[] members)` If IgnoreMeasureForNonJoiningDimension is set to true and one or more members are on unrelated dimension for the measure in current context then returns true.
`RuntimeException`	`newEvalException(Object context, String s)` Creates an exception which indicates that an error has occurred during the runtime evaluation of a function.
`Evaluator`	`push()` Creates a new Evaluator with the same context as this evaluator.
`Evaluator`	`push(boolean nonEmpty)` Deprecated. Use `savepoint()` followed by `setNonEmpty(boolean)`; will be removed in mondrian-4
`Evaluator`	`push(boolean nonEmpty, boolean nativeEnabled)` Deprecated. Use `savepoint()` followed by `setNonEmpty(boolean)` and `setNativeEnabled(boolean)`; will be removed in mondrian-4.
`Evaluator`	`push(Member member)` Deprecated. Use `savepoint()` followed by `setContext(Member)`; will be removed in mondrian-4
`Evaluator`	`push(Member[] members)` Deprecated. Use `savepoint()` followed by `setContext(Member[])`; will be removed in mondrian-4
`Evaluator`	`pushAggregation(List<List<Member>> list)` Returns a new Aggregator whose aggregation context adds a given list of tuples, and whose evaluation context is the same as this Aggregator.
`void`	`restore(int savepoint)` Restores previous evaluator.
`int`	`savepoint()` Creates a savepoint encapsulating the current state of the evalutor.
`void`	`setContext(List<Member> memberList)` Sets the context to a list of members.
`void`	`setContext(List<Member> memberList, boolean safe)` Sets the context to a list of members, optionally skipping the check whether it is necessary to store the previous member of each hierarchy.
`Member`	`setContext(Member member)` Makes `member` the current member of its hierarchy.
`void`	`setContext(Member[] members)` Sets the context to an array of members.
`void`	`setContext(Member[] members, boolean safe)` Sets the context to an array of members, optionally skipping the check whether it is necessary to store the previous member of each hierarchy.
`void`	`setContext(Member member, boolean safe)` Makes `member` the current member of its hierarchy.
`void`	`setEvalAxes(boolean evalAxes)` Indicate whether the evaluator is evaluating the axes
`void`	`setIterationLength(int length)` Sets the iteration length for the current evaluator context
`void`	`setNativeEnabled(boolean nativeEnabled)` Sets whether native evaluation should be used.
`void`	`setNonEmpty(boolean nonEmpty)` Sets whether an expression evaluation should filter out empty cells.
`boolean`	`shouldIgnoreUnrelatedDimensions()` Returns whether hierarchies unrelated to the measure in the current context should be ignored.

- Method Detail
  - getCube
```
Cube getCube()
```
    Returns the current cube.
  - getQuery
```
Query getQuery()
```
    Returns the current query.
  - getQueryStartTime
```
Date getQueryStartTime()
```
    Returns the start time of the current query.
  - savepoint
```
int savepoint()
```
    Creates a savepoint encapsulating the current state of the evalutor. You can restore the evaluator to this state by calling restore(int) with the value returned by this method.
    This method is typically called before evaluating an expression which is known to corrupt the evaluation context.
    Multiple savepoints may be active at the same time for the same evaluator. And, it is allowable to restore to the save savepoint more than once (or not at all). However, when you have rolled back to a particular savepoint you may not restore to a later savepoint.
    
    Returns:
    
    Evaluator with each given member overriding the state of the current Evaluator for its hierarchy
  - push
```
Evaluator push(Member[] members)
```
    Deprecated. Use savepoint() followed by setContext(Member[]); will be removed in mondrian-4
    
    Creates a new Evaluator with each given member overriding the context of the current Evaluator for its hierarchy. Other hierarchies retain the same context as this Evaluator.
    In mondrian-3.3 and later, a more efficient way to save the state of an evaluator is to call savepoint() followed by restore(int). We recommend using those methods.
    
    Parameters:
    
    members - Array of members to add to the context
    
    Returns:
    
    Evaluator with each given member overriding the state of the current Evaluator for its hierarchy
  - push
```
Evaluator push()
```
    Creates a new Evaluator with the same context as this evaluator.
    This method is typically called before evaluating an expression which may corrupt the evaluation context.
    In mondrian-3.3 and later, a more efficient way to save the state of an evaluator is to call savepoint() followed by restore(int). We recommend using those methods most of the time.
    However, it makes sense to use this method in the constructor of an iterator. It allows the iterator to modify its evaluation context without affecting the evaluation context of the calling code. This behavior cannot be achieved using savepoint.
    
    Returns:
    
    Evaluator with each given member overriding the state of the current Evaluator for its hierarchy
  - push
```
Evaluator push(Member member)
```
    Deprecated. Use savepoint() followed by setContext(Member); will be removed in mondrian-4
    
    Creates a new Evaluator with the same context except for one member.
    This method is typically called before evaluating an expression which may corrupt the evaluation context.
    In mondrian-3.3 and later, a more efficient way to save the state of an evaluator is to call savepoint() followed by restore(int). We recommend using those methods.
    
    Parameters:
    
    member - Member to add to the context
    
    Returns:
    
    Evaluator with each given member overriding the state of the current Evaluator for its hierarchy
  - push
```
Evaluator push(boolean nonEmpty)
```
    Deprecated. Use savepoint() followed by setNonEmpty(boolean); will be removed in mondrian-4
    
    Creates a new evaluator with the same state except nonEmpty property
    In mondrian-3.3 and later, a more efficient way to save the state of an evaluator is to call savepoint() followed by restore(int). We recommend using those methods.
  - push
```
Evaluator push(boolean nonEmpty,
               boolean nativeEnabled)
```
    Deprecated. Use savepoint() followed by setNonEmpty(boolean) and setNativeEnabled(boolean); will be removed in mondrian-4.
    
    Creates a new evaluator with the same state except nonEmpty and nativeEnabled properties.
    In mondrian-3.3 and later, a more efficient way to save the state of an evaluator is to call savepoint() followed by restore(int). We recommend using those methods.
  - restore
```
void restore(int savepoint)
```
    Restores previous evaluator.
    
    Parameters:
    
    savepoint - Savepoint returned by savepoint()
  - setContext
```
Member setContext(Member member)
```
    Makes member the current member of its hierarchy.
    
    Parameters:
    
    member - New member
    
    Returns:
    
    Previous member of this hierarchy
  - setContext
```
void setContext(Member member,
                boolean safe)
```
    Makes member the current member of its hierarchy.
    If safe, checks whether this is the first time that a member of this hierarchy has been changed since savepoint() was called. If so, saves the previous member. If safe is false, never saves the previous member.
    Use safe = false only if you are sure that the context has been set before. For example,
    int n = 0; for (Member member : members) { evaluator.setContext(member, n++ > 0); }
    
    Parameters:
    
    member - New member
    
    safe - Whether to store the member of this hierarchy that was current last time that savepoint() was called.
  - setContext
```
void setContext(List<Member> memberList)
```
    Sets the context to a list of members.
    Equivalent to
    for (Member member : memberList) { setContext(member); }
    
    Parameters:
    
    memberList - List of members
  - setContext
```
void setContext(List<Member> memberList,
                boolean safe)
```
    Sets the context to a list of members, optionally skipping the check whether it is necessary to store the previous member of each hierarchy.
    Equivalent to
    for (Member member : memberList) { setContext(member, safe); }
    
    Parameters:
    
    memberList - List of members
    
    safe - Whether to store the member of each hierarchy that was current last time that savepoint() was called.
  - setContext
```
void setContext(Member[] members)
```
    Sets the context to an array of members.
    Equivalent to
    for (Member member : memberList) { setContext(member); }
    
    Parameters:
    
    members - Array of members
  - setContext
```
void setContext(Member[] members,
                boolean safe)
```
    Sets the context to an array of members, optionally skipping the check whether it is necessary to store the previous member of each hierarchy.
    Equivalent to
    for (Member member : memberList) { setContext(member, safe); }
    
    Parameters:
    
    members - Array of members
    
    safe - Whether to store the member of each hierarchy that was current last time that savepoint() was called.
  - getContext
```
Member getContext(Hierarchy hierarchy)
```
  - evaluateCurrent
```
Object evaluateCurrent()
```
    Calculates and returns the value of the cell at the current context.
  - getFormatString
```
String getFormatString()
```
    Returns the format string for this cell. This is computed by evaluating the format expression in the current context, and therefore different cells may have different format strings.
  - format
```
String format(Object o)
```
    Formats a value as a string according to the current context's format.
  - format
```
String format(Object o,
              String formatString)
```
    Formats a value as a string according to the current context's format, using a given format string.
  - getDepth
```
int getDepth()
```
    Deprecated. Will be removed in mondrian-4
    
    Obsolete method.
  - getParent
```
Evaluator getParent()
```
    Deprecated. Will be removed in mondrian-4
    
    Returns parent evaluator.
  - getConnectionLocale
```
Locale getConnectionLocale()
```
    Returns the connection's locale.
  - getProperty
```
Object getProperty(String name,
                   Object defaultValue)
```
    Retrieves the value of property name. If more than one member in the current context defines that property, the one with the highest solve order has precedence.
    If the property is not defined, default value is returned.
  - getSchemaReader
```
SchemaReader getSchemaReader()
```
    Returns a SchemaReader appropriate for the current access-control context.
  - getCachedResult
```
Object getCachedResult(ExpCacheDescriptor key)
```
    Simple caching of the result of an Exp. The key for the cache consists of all members of the current context that exp depends on. Members of independent hierarchies are not part of the key.
    
    See Also:
    
    Calc.dependsOn(Hierarchy)
  - isNonEmpty
```
boolean isNonEmpty()
```
    Returns true for an axis that is NON EMPTY.
    May be used by expression evaluators to optimize their result. For example, a top-level crossjoin may be optimized by removing all non-empty set elements before performing the crossjoin. This is possible because of the identity
    nonempty(crossjoin(a, b)) == nonempty(crossjoin(nonempty(a), nonempty(b));
  - setNonEmpty
```
void setNonEmpty(boolean nonEmpty)
```
    Sets whether an expression evaluation should filter out empty cells. Allows expressions to modify non empty flag to evaluate their children.
  - newEvalException
```
RuntimeException newEvalException(Object context,
                                  String s)
```
    Creates an exception which indicates that an error has occurred during the runtime evaluation of a function. The caller should then throw that exception.
  - getSetEvaluator
```
Evaluator.SetEvaluator getSetEvaluator(Exp exp,
                                       boolean create)
```
    Returns an evaluator for a set.
    
    Parameters:
    
    exp - Expression
    
    create - Whether to create evaluator if not found
    
    Returns:
    
    Evaluator of named set
  - getNamedSetEvaluator
```
Evaluator.NamedSetEvaluator getNamedSetEvaluator(NamedSet namedSet,
                                                 boolean create)
```
    Returns an evaluator for a named set.
    
    Parameters:
    
    namedSet - Named set
    
    create - Whether to create evaluator if not found
    
    Returns:
    
    Evaluator of named set
  - getMembers
```
Member[] getMembers()
```
    Returns an array of the members which make up the current context.
  - getNonAllMembers
```
Member[] getNonAllMembers()
```
    Returns an array of the non-All members which make up the current context.
    Notes:
    - The 0th element is a measure, but otherwise the order of the members is unspecified.
    - No hierarchy occurs more than once.
    - In rare circumstances, some of the members may be an 'All' member.
    - The list may contain calculated members.
  - getMissCount
```
int getMissCount()
```
    Returns the number of times that this evaluator has told a lie when retrieving cell values.
  - getParameterValue
```
Object getParameterValue(ParameterSlot slot)
```
    Returns the value of a parameter, evaluating its default value if it is not set.
  - getIterationLength
```
int getIterationLength()
```
    Returns:
    
    the iteration length of the current context
  - setIterationLength
```
void setIterationLength(int length)
```
    Sets the iteration length for the current evaluator context
    
    Parameters:
    
    length - length to be set
  - isEvalAxes
```
boolean isEvalAxes()
```
    Returns:
    
    true if evaluating axes
  - setEvalAxes
```
void setEvalAxes(boolean evalAxes)
```
    Indicate whether the evaluator is evaluating the axes
    
    Parameters:
    
    evalAxes - true if evaluating axes
  - pushAggregation
```
Evaluator pushAggregation(List<List<Member>> list)
```
    Returns a new Aggregator whose aggregation context adds a given list of tuples, and whose evaluation context is the same as this Aggregator.
    
    Parameters:
    
    list - List of tuples
    
    Returns:
    
    Aggregator with list added to its aggregation context
  - shouldIgnoreUnrelatedDimensions
```
boolean shouldIgnoreUnrelatedDimensions()
```
    Returns whether hierarchies unrelated to the measure in the current context should be ignored.
    
    Returns:
    
    whether hierarchies unrelated to the measure in the current context should be ignored
  - getMeasureCube
```
Cube getMeasureCube()
```
    Returns the base (non-virtual) cube that the current measure in the context belongs to.
    
    Returns:
    
    Cube
  - mightReturnNullForUnrelatedDimension
```
boolean mightReturnNullForUnrelatedDimension()
```
    Returns whether it is necessary to check whether to return null for an unrelated dimension. If false, we never need to check: we can assume that needToReturnNullForUnrelatedDimension(mondrian.olap.Member[]) will always return false.
    
    Returns:
    
    whether it is necessary to check whether to return null for an unrelated dimension
  - needToReturnNullForUnrelatedDimension
```
boolean needToReturnNullForUnrelatedDimension(Member[] members)
```
    If IgnoreMeasureForNonJoiningDimension is set to true and one or more members are on unrelated dimension for the measure in current context then returns true.
    You must not call this method unless mightReturnNullForUnrelatedDimension() has returned true.
    
    Parameters:
    
    members - Dimensions for the members need to be checked whether related or unrelated
    
    Returns:
    
    boolean
  - nativeEnabled
```
boolean nativeEnabled()
```
    Returns whether native evaluation is enabled in this context.
    
    Returns:
    
    whether native evaluation is enabled in this context
  - setNativeEnabled
```
void setNativeEnabled(boolean nativeEnabled)
```
    Sets whether native evaluation should be used.
    
    Parameters:
    
    nativeEnabled - Whether native evaluation should be used
  - currentIsEmpty
```
boolean currentIsEmpty()
```
    Returns whether the current context is an empty cell.
    
    Returns:
    
    Whether the current context is an empty cell
  - getPreviousContext
```
Member getPreviousContext(Hierarchy hierarchy)
```
    Returns the member that was the current evaluation context for a particular hierarchy before the most recent change in context.
    
    Parameters:
    
    hierarchy - Hierarchy
    
    Returns:
    
    Previous context member for given hierarchy
  - getTiming
```
QueryTiming getTiming()
```
    Returns the query timing context for this execution.
    
    Returns:
    
    query timing context

Interface Evaluator

Nested Class Summary

Method Summary

Method Detail

getCube

getQuery

getQueryStartTime

savepoint

push

push

push

push

push

restore

setContext

setContext

setContext

setContext

setContext

setContext

getContext

evaluateCurrent

getFormatString

format

format

getDepth

getParent

getConnectionLocale

getProperty

getSchemaReader

getCachedResult

isNonEmpty

setNonEmpty

newEvalException

getSetEvaluator

getNamedSetEvaluator

getMembers

getNonAllMembers

getMissCount

getParameterValue

getIterationLength

setIterationLength

isEvalAxes

setEvalAxes

pushAggregation

shouldIgnoreUnrelatedDimensions

getMeasureCube

mightReturnNullForUnrelatedDimension

needToReturnNullForUnrelatedDimension

nativeEnabled

setNativeEnabled

currentIsEmpty

getPreviousContext

getTiming