org.cumulus4j.store.query
Class QueryEvaluator

java.lang.Object
  org.cumulus4j.store.query.QueryEvaluator

Direct Known Subclasses:

JDOQueryEvaluator

public abstract class QueryEvaluator
extends Object

API-agnostic query implementation. An instance of this class performs the actual query. It is used by both APIs, JDO and JPA.

Author:

Marco หงุ่ยตระกูล-Schulze - marco at nightlabs dot de

Field Summary

static String

RESULTS_SET Name under which any set of results are stored in the state map.

Constructor Summary

QueryEvaluator(String language, Query query, QueryCompilation compilation, Map<String,Object> parameterValues, ClassLoaderResolver clr, PersistenceManagerConnection pmConn)

Method Summary

protected abstract Collection<Object>	evaluateSubquery(Query subquery, QueryCompilation compilation, Object outerCandidate)
List<Object>	execute()
Set<Long>	getAllDataEntryIDsForCandidateClasses(Set<ClassMeta> candidateClassMetas)
String	getCandidateAlias()
ClassLoaderResolver	getClassLoaderResolver()
QueryCompilation	getCompilation()
CryptoContext	getCryptoContext()
EncryptionHandler	getEncryptionHandler()
ExecutionContext	getExecutionContext()
AbstractExpressionEvaluator<?>	getExpressionEvaluator()
String	getLanguage()
Object	getObjectForClassMetaAndObjectIDString(ClassMeta classMeta, String objectIDString)
Object	getObjectForDataEntry(DataEntry dataEntry)
Map<String,Object>	getParameterValues()
PersistenceManagerConnection	getPersistenceManagerConnection()
PersistenceManager	getPersistenceManagerForData()
PersistenceManager	getPersistenceManagerForIndex()
Query	getQuery()
Map<String,Object>	getState()
Cumulus4jStoreManager	getStoreManager()
Class<?>	getValueType(Symbol symbol) Get a Symbol's valueType by taking ResultDescriptors into account.
Class<?>	getValueType(Symbol symbol, boolean throwExceptionIfNotFound) Get a Symbol's valueType by taking ResultDescriptors into account.
boolean	isComplete()
ResultDescriptor	popResultDescriptor() Pop a ResultDescriptor from the stack.
void	pushResultDescriptor(ResultDescriptor resultDescriptor) Push a ResultDescriptor onto the stack.
void	setIncomplete()

Methods inherited from class java.lang.Object

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

Field Detail

RESULTS_SET

public static final String RESULTS_SET

Name under which any set of results are stored in the state map. Used for aggregation.

See Also:

Constant Field Values

Constructor Detail

QueryEvaluator

public QueryEvaluator(String language,
                      Query query,
                      QueryCompilation compilation,
                      Map<String,Object> parameterValues,
                      ClassLoaderResolver clr,
                      PersistenceManagerConnection pmConn)

Parameters:

language - Query language (JDOQL, JPQL, etc)

compilation - generic compilation

parameterValues - Input values for the params

clr - ClassLoader resolver

pmConn - our backend-PersistenceManager connection(s).

Method Detail

isComplete

public boolean isComplete()

setIncomplete

public void setIncomplete()

getLanguage

public String getLanguage()

getCandidateAlias

public String getCandidateAlias()

getQuery

public Query getQuery()

getCompilation

public QueryCompilation getCompilation()

getParameterValues

public Map<String,Object> getParameterValues()

getState

public Map<String,Object> getState()

getClassLoaderResolver

public ClassLoaderResolver getClassLoaderResolver()

getExecutionContext

public ExecutionContext getExecutionContext()

getStoreManager

public Cumulus4jStoreManager getStoreManager()

getPersistenceManagerConnection

public PersistenceManagerConnection getPersistenceManagerConnection()

getPersistenceManagerForData

public PersistenceManager getPersistenceManagerForData()

getPersistenceManagerForIndex

public PersistenceManager getPersistenceManagerForIndex()

getEncryptionHandler

public EncryptionHandler getEncryptionHandler()

pushResultDescriptor

public void pushResultDescriptor(ResultDescriptor resultDescriptor)

Push a ResultDescriptor onto the stack.

Parameters:

resultDescriptor - the descriptor to be pushed.

popResultDescriptor

public ResultDescriptor popResultDescriptor()

Pop a ResultDescriptor from the stack.

Returns:

the popped descriptor (which is the last one pushed).

getValueType

public Class<?> getValueType(Symbol symbol)

Get a Symbol's valueType by taking ResultDescriptors into account. Delegates to getValueType(Symbol, boolean) with throwExceptionIfNotFound == true.

Parameters:

symbol - the symbol whose valueType should be resolved.

Returns:

the type - never null.

See Also:

getValueType(Symbol, boolean)

getValueType

public Class<?> getValueType(Symbol symbol,
                             boolean throwExceptionIfNotFound)

Get a Symbol's valueType by taking ResultDescriptors into account.

This method (or alternatively getValueType(Symbol)) should always be used instead of directly accessing Symbol.getValueType()!!! This allows for implicit variables (which are not declared).

This method first checks, if Symbol.getValueType() returns a value and if so, returns it. Otherwise it searches the stack of ResultDescriptors (maintained via pushResultDescriptor(ResultDescriptor) and popResultDescriptor()) and returns the first found ResultDescriptor.getResultType().

Parameters:

symbol - the symbol whose valueType should be resolved.

throwExceptionIfNotFound - whether to throw an IllegalStateException [exception type might be changed without notice!], if the type cannot be resolved. If false this method returns null instead.

Returns:

the type or null, if not resolvable and throwExceptionIfNotFound == false.

See Also:

getValueType(Symbol), pushResultDescriptor(ResultDescriptor), popResultDescriptor()

evaluateSubquery

protected abstract Collection<Object> evaluateSubquery(Query subquery,
                                                       QueryCompilation compilation,
                                                       Object outerCandidate)

execute

public List<Object> execute()

getExpressionEvaluator

public AbstractExpressionEvaluator<?> getExpressionEvaluator()

getObjectForDataEntry

public Object getObjectForDataEntry(DataEntry dataEntry)

getObjectForClassMetaAndObjectIDString

public Object getObjectForClassMetaAndObjectIDString(ClassMeta classMeta,
                                                     String objectIDString)

getAllDataEntryIDsForCandidateClasses

public Set<Long> getAllDataEntryIDsForCandidateClasses(Set<ClassMeta> candidateClassMetas)

getCryptoContext

public CryptoContext getCryptoContext()