internal QueryRewriter(EdmType generatedType, ViewgenContext context, ViewGenMode typesGenerationMode)
{
Debug.Assert(typesGenerationMode != ViewGenMode.GenerateAllViews);
_typesGenerationMode = typesGenerationMode;
_context = context;
_generatedType = generatedType;
_domainMap = context.MemberMaps.LeftDomainMap;
_config = context.Config;
_identifiers = context.CqlIdentifiers;
_qp = new RewritingProcessor<Tile<FragmentQuery>>(new DefaultTileProcessor<FragmentQuery>(context.LeftFragmentQP));
_extentPath = new MemberPath(context.Extent);
_keyAttributes = new List<MemberPath>(MemberPath.GetKeyMembers(context.Extent, _domainMap));
// populate _fragmentQueries and _views
foreach (var leftCellWrapper in _context.AllWrappersForExtent)
{
var query = leftCellWrapper.FragmentQuery;
Tile<FragmentQuery> tile = CreateTile(query);
_fragmentQueries.Add(query);
_views.Add(tile);
}
Debug.Assert(_views.Count > 0);
AdjustMemberDomainsForUpdateViews();
// must be done after adjusting domains
_domainQuery = GetDomainQuery(FragmentQueries, generatedType);
_usedViews = new HashSet<FragmentQuery>();
}
// <summary>
// Fixes the range of the restriction in accordance with <paramref name="range" />.
// Member restriction must be complete for this operation.
// </summary>
internal override DomainBoolExpr FixRange(Set<Constant> range, MemberDomainMap memberDomainMap)
{
Debug.Assert(IsComplete, "Ranges are fixed only for complete scalar restrictions.");
var newPossibleValues = memberDomainMap.GetDomain(RestrictedMemberSlot.MemberPath);
BoolLiteral newLiteral = new ScalarRestriction(RestrictedMemberSlot, new Domain(range, newPossibleValues));
return newLiteral.GetDomainBoolExpression(memberDomainMap);
}
internal override BoolExpr<DomainConstraint<BoolLiteral, Constant>> GetDomainBoolExpression(MemberDomainMap domainMap)
{
// Essentially say that the variable can take values true or false and here its value is only true
IEnumerable<Constant> actualValues = new Constant[] { new ScalarConstant(true) };
IEnumerable<Constant> possibleValues = new Constant[] { new ScalarConstant(true), new ScalarConstant(false) };
var variableDomain = new Set<Constant>(possibleValues, Constant.EqualityComparer).MakeReadOnly();
var thisDomain = new Set<Constant>(actualValues, Constant.EqualityComparer).MakeReadOnly();
var result = MakeTermExpression(this, variableDomain, thisDomain);
return result;
}
internal MemberMaps(
ViewTarget viewTarget, MemberProjectionIndex projectedSlotMap,
MemberDomainMap queryDomainMap, MemberDomainMap updateDomainMap)
{
m_projectedSlotMap = projectedSlotMap;
m_queryDomainMap = queryDomainMap;
m_updateDomainMap = updateDomainMap;
Debug.Assert(m_queryDomainMap != null);
Debug.Assert(m_updateDomainMap != null);
Debug.Assert(m_projectedSlotMap != null);
m_viewTarget = viewTarget;
}
// effects: Creates a view generator object that can be used to generate views
// based on usedCells (projectedSlotMap are useful for deciphering the fields)
internal BasicViewGenerator(
MemberProjectionIndex projectedSlotMap, List<LeftCellWrapper> usedCells, FragmentQuery activeDomain,
ViewgenContext context, MemberDomainMap domainMap, ErrorLog errorLog, ConfigViewGenerator config)
{
Debug.Assert(usedCells.Count > 0, "No used cells");
m_projectedSlotMap = projectedSlotMap;
m_usedCells = usedCells;
m_viewgenContext = context;
m_activeDomain = activeDomain;
m_errorLog = errorLog;
m_config = config;
m_domainMap = domainMap;
}
internal override BoolExpr<DomainConstraint<BoolLiteral, Constant>> FixRange(Set<Constant> range, MemberDomainMap memberDomainMap)
{
Debug.Assert(range.Count == 1, "For BoolLiterals, there should be precisely one value - true or false");
var scalar = (ScalarConstant)range.First();
var expr = GetDomainBoolExpression(memberDomainMap);
if ((bool)scalar.Value == false)
{
// The range of the variable was "inverted". Return a NOT of
// the expression
expr = new NotExpr<DomainConstraint<BoolLiteral, Constant>>(expr);
}
return expr;
}
// effects: Creates a ViewGenerator object that is capable of
// producing query or update mapping views given the relevant schema
// given the "cells"
internal ViewGenerator(
CellGroup cellGroup, ConfigViewGenerator config,
List<ForeignConstraint> foreignKeyConstraints,
StorageEntityContainerMapping entityContainerMapping)
{
m_cellGroup = cellGroup;
m_config = config;
m_queryRewriterCache = new Dictionary<EntitySetBase, QueryRewriter>();
m_foreignKeyConstraints = foreignKeyConstraints;
m_entityContainerMapping = entityContainerMapping;
var inheritanceGraph =
MetadataHelper.BuildUndirectedGraphOfTypes(entityContainerMapping.StorageMappingItemCollection.EdmItemCollection);
SetConfiguration(entityContainerMapping);
// We fix all the cells at this point
m_queryDomainMap = new MemberDomainMap(
ViewTarget.QueryView, m_config.IsValidationEnabled, cellGroup,
entityContainerMapping.StorageMappingItemCollection.EdmItemCollection, m_config, inheritanceGraph);
m_updateDomainMap = new MemberDomainMap(
ViewTarget.UpdateView, m_config.IsValidationEnabled, cellGroup,
entityContainerMapping.StorageMappingItemCollection.EdmItemCollection, m_config, inheritanceGraph);
// We now go and fix the queryDomain map so that it has all the
// values from the S-side as well -- this is needed for domain
// constraint propagation, i.e., values from the S-side get
// propagated to te oneOfConst on the C-side. So we better get
// the "possiblveValues" stuff to contain those constants as well
MemberDomainMap.PropagateUpdateDomainToQueryDomain(cellGroup, m_queryDomainMap, m_updateDomainMap);
UpdateWhereClauseForEachCell(cellGroup, m_queryDomainMap, m_updateDomainMap, m_config);
// We need to simplify cell queries, yet we don't want the conditions to disappear
// So, add an extra value to the domain, temporarily
var queryOpenDomain = m_queryDomainMap.GetOpenDomain();
var updateOpenDomain = m_updateDomainMap.GetOpenDomain();
// Make sure the WHERE clauses of the cells reflect the changes
foreach (var cell in cellGroup)
{
cell.CQuery.WhereClause.FixDomainMap(queryOpenDomain);
cell.SQuery.WhereClause.FixDomainMap(updateOpenDomain);
cell.CQuery.WhereClause.ExpensiveSimplify();
cell.SQuery.WhereClause.ExpensiveSimplify();
cell.CQuery.WhereClause.FixDomainMap(m_queryDomainMap);
cell.SQuery.WhereClause.FixDomainMap(m_updateDomainMap);
}
}
/// <summary>
/// Returns a boolean expression that is domain-aware and ready for optimizations etc.
/// </summary>
/// <param name="domainMap">Maps members to the values that each member can take;
/// it can be null in which case the possible and actual values are the same.</param>
internal override DomainBoolExpr GetDomainBoolExpression(MemberDomainMap domainMap)
{
// Get the variable name from the slot's memberpath and the possible domain values from the slot
DomainTermExpr result;
if (domainMap != null)
{
// Look up the domain from the domainMap
var domain = domainMap.GetDomain(m_restrictedMemberSlot.MemberPath);
result = MakeTermExpression(this, domain, m_domain.Values);
}
else
{
result = MakeTermExpression(this, m_domain.AllPossibleValues, m_domain.Values);
}
return result;
}
internal override BoolExpr <DomainConstraint <BoolLiteral, Constant> > GetDomainBoolExpression(MemberDomainMap domainMap)
{
// Essentially say that the variable can take values true or false and here its value is only true
IEnumerable <Constant> actualValues = new Constant[] { new ScalarConstant(true) };
IEnumerable <Constant> possibleValues = new Constant[] { new ScalarConstant(true), new ScalarConstant(false) };
var variableDomain = new Set <Constant>(possibleValues, Constant.EqualityComparer).MakeReadOnly();
var thisDomain = new Set <Constant>(actualValues, Constant.EqualityComparer).MakeReadOnly();
var result = MakeTermExpression(this, variableDomain, thisDomain);
return(result);
}
internal abstract DomainBoolExpr GetDomainBoolExpression(MemberDomainMap domainMap);
// effects: Creates a visitor with the JoinTreeNode remapping
// information in remap
private RemapBoolVisitor(MemberDomainMap memberDomainMap, Dictionary <MemberPath, MemberPath> remap)
{
m_remap = remap;
m_memberDomainMap = memberDomainMap;
}
internal ViewgenContext(
ViewTarget viewTarget, EntitySetBase extent, IList<Cell> extentCells,
CqlIdentifiers identifiers, ConfigViewGenerator config, MemberDomainMap queryDomainMap,
MemberDomainMap updateDomainMap, EntityContainerMapping entityContainerMapping)
{
foreach (var cell in extentCells)
{
Debug.Assert(extent.Equals(cell.GetLeftQuery(viewTarget).Extent));
Debug.Assert(cell.CQuery.NumProjectedSlots == cell.SQuery.NumProjectedSlots);
}
m_extent = extent;
m_viewTarget = viewTarget;
m_config = config;
m_edmItemCollection = entityContainerMapping.StorageMappingItemCollection.EdmItemCollection;
m_entityContainerMapping = entityContainerMapping;
m_identifiers = identifiers;
// create a copy of updateDomainMap so generation of query views later on is not affected
// it is modified in QueryRewriter.AdjustMemberDomainsForUpdateViews
updateDomainMap = updateDomainMap.MakeCopy();
// Create a signature generator that handles all the
// multiconstant work and generating the signatures
var domainMap = viewTarget == ViewTarget.QueryView ? queryDomainMap : updateDomainMap;
m_memberMaps = new MemberMaps(
viewTarget, MemberProjectionIndex.Create(extent, m_edmItemCollection), queryDomainMap, updateDomainMap);
// Create left fragment KB: includes constraints for the extent to be constructed
var leftKB = new FragmentQueryKBChaseSupport();
leftKB.CreateVariableConstraints(extent, domainMap, m_edmItemCollection);
m_leftFragmentQP = new FragmentQueryProcessor(leftKB);
m_rewritingCache = new Dictionary<FragmentQuery, Tile<FragmentQuery>>(
FragmentQuery.GetEqualityComparer(m_leftFragmentQP));
// Now using the signatures, create new cells such that
// "extent's" query (C or S) is described in terms of multiconstants
if (!CreateLeftCellWrappers(extentCells, viewTarget))
{
return;
}
// Create right fragment KB: includes constraints for all extents and association roles of right queries
var rightKB = new FragmentQueryKBChaseSupport();
var rightDomainMap = viewTarget == ViewTarget.QueryView ? updateDomainMap : queryDomainMap;
foreach (var leftCellWrapper in m_cellWrappers)
{
var rightExtent = leftCellWrapper.RightExtent;
rightKB.CreateVariableConstraints(rightExtent, rightDomainMap, m_edmItemCollection);
rightKB.CreateAssociationConstraints(rightExtent, rightDomainMap, m_edmItemCollection);
}
if (m_viewTarget == ViewTarget.UpdateView)
{
CreateConstraintsForForeignKeyAssociationsAffectingThisWrapper(rightKB, rightDomainMap);
}
m_rightFragmentQP = new FragmentQueryProcessor(rightKB);
// Check for concurrency control tokens
if (m_viewTarget == ViewTarget.QueryView)
{
CheckConcurrencyControlTokens();
}
// For backward compatibility -
// order wrappers by increasing domain size, decreasing number of attributes
m_cellWrappers.Sort(LeftCellWrapper.Comparer);
}
private FixRangeVisitor(MemberDomainMap memberDomainMap)
{
this.m_memberDomainMap = memberDomainMap;
}
internal void FixDomainMap(MemberDomainMap domainMap)
{
this.m_tree = BoolExpression.FixRangeVisitor.FixRange(this.m_tree, domainMap);
}
internal static BoolExpression CreateLiteral(
BoolLiteral literal,
MemberDomainMap memberDomainMap)
{
return(new BoolExpression(literal.GetDomainBoolExpression(memberDomainMap), memberDomainMap));
}
internal void ReduceEnumerableDomainToEnumeratedValues(ConfigViewGenerator config)
{
MemberDomainMap.ReduceEnumerableDomainToEnumeratedValues(this.m_conditionDomainMap, config, this.m_edmItemCollection);
MemberDomainMap.ReduceEnumerableDomainToEnumeratedValues(this.m_nonConditionDomainMap, config, this.m_edmItemCollection);
}
internal void FixDomainMap(MemberDomainMap domainMap)
{
DebugCheck.NotNull(domainMap);
m_tree = FixRangeVisitor.FixRange(m_tree, domainMap);
}
// effects: Creates a boolean expression based on expr
internal BoolExpression(DomainBoolExpr expr, MemberDomainMap memberDomainMap)
{
m_tree = expr;
m_memberDomainMap = memberDomainMap;
}
// <summary>
// Find the Foreign Key Associations that relate EntitySets used in these left cell wrappers and
// add any equivalence facts between sets implied by 1:1 associations.
// We can collect other implication facts but we don't have a scenario that needs them( yet ).
// </summary>
private void CreateConstraintsForForeignKeyAssociationsAffectingThisWrapper(
FragmentQueryKB rightKB, MemberDomainMap rightDomainMap)
{
var oneToOneForeignKeyAssociationSetsForThisWrapper
= new OneToOneFkAssociationsForEntitiesFilter()
.Filter(
m_cellWrappers.Select(it => it.RightExtent).OfType<EntitySet>().Select(it => it.ElementType).ToList(),
m_entityContainerMapping.EdmEntityContainer.BaseEntitySets.OfType<AssociationSet>());
// Collect the facts for the foreign key association sets that are 1:1 and affecting this wrapper
foreach (var assocSet in oneToOneForeignKeyAssociationSetsForThisWrapper)
{
rightKB.CreateEquivalenceConstraintForOneToOneForeignKeyAssociation(assocSet, rightDomainMap);
}
}
// requires: this domainMap has been created for the C-side
// effects: Fixes the mergedDomain map in this by merging entries
// available in updateDomainMap
internal static void PropagateUpdateDomainToQueryDomain(
IEnumerable<Cell> cells, MemberDomainMap queryDomainMap, MemberDomainMap updateDomainMap)
{
foreach (var cell in cells)
{
var cQuery = cell.CQuery;
var sQuery = cell.SQuery;
for (var i = 0; i < cQuery.NumProjectedSlots; i++)
{
var cSlot = cQuery.ProjectedSlotAt(i) as MemberProjectedSlot;
var sSlot = sQuery.ProjectedSlotAt(i) as MemberProjectedSlot;
if (cSlot == null
|| sSlot == null)
{
continue;
}
// Get the domain for sSlot and merge with cSlot's
var cPath = cSlot.MemberPath;
var sPath = sSlot.MemberPath;
var cDomain = queryDomainMap.GetDomainInternal(cPath);
var sDomain = updateDomainMap.GetDomainInternal(sPath);
// skip NULL because if c-side member is nullable, it's already there, and otherwise can't be taken
// skip negated because negated values are translated in a special way
cDomain.Unite(sDomain.Where(constant => !constant.IsNull() && !(constant is NegatedConstant)));
if (updateDomainMap.IsConditionMember(sPath)
&& !queryDomainMap.IsConditionMember(cPath))
{
// record this member so KB knows we have to generate constraints for it
queryDomainMap.m_projectedConditionMembers.Add(cPath);
}
}
}
ExpandNegationsInDomainMap(queryDomainMap.m_conditionDomainMap);
ExpandNegationsInDomainMap(queryDomainMap.m_nonConditionDomainMap);
}
internal abstract BoolExpr <DomainConstraint <BoolLiteral, Constant> > FixRange(
Set <Constant> range,
MemberDomainMap memberDomainMap);
internal override BoolExpr <DomainConstraint <BoolLiteral, Constant> > FixRange(Set <Constant> range, MemberDomainMap memberDomainMap)
{
Debug.Assert(range.Count == 1, "For BoolLiterals, there should be precisely one value - true or false");
var scalar = (ScalarConstant)range.First();
var expr = GetDomainBoolExpression(memberDomainMap);
if ((bool)scalar.Value == false)
{
// The range of the variable was "inverted". Return a NOT of
// the expression
expr = new NotExpr <DomainConstraint <BoolLiteral, Constant> >(expr);
}
return(expr);
}
// requires: The CellConstantDomains in the OneOfConsts of the where
// clause are partially done
// effects: Given the domains of different variables in domainMap,
// fixes the whereClause of this such that all the
// CellConstantDomains in OneOfConsts are complete
internal void UpdateWhereClause(MemberDomainMap domainMap)
{
var atoms = new List<BoolExpression>();
foreach (var atom in WhereClause.Atoms)
{
var literal = atom.AsLiteral;
var restriction = literal as MemberRestriction;
Debug.Assert(restriction != null, "All bool literals must be OneOfConst at this point");
// The oneOfConst needs to be fixed with the new possible values from the domainMap.
var possibleValues = domainMap.GetDomain(restriction.RestrictedMemberSlot.MemberPath);
var newOneOf = restriction.CreateCompleteMemberRestriction(possibleValues);
// Prevent optimization of single constraint e.g: "300 in (300)"
// But we want to optimize type constants e.g: "category in (Category)"
// To prevent optimization of bool expressions we add a Sentinel OneOF
var scalarConst = restriction as ScalarRestriction;
var addSentinel =
scalarConst != null &&
!scalarConst.Domain.Contains(Constant.Null) &&
!scalarConst.Domain.Contains(Constant.NotNull) &&
!scalarConst.Domain.Contains(Constant.Undefined);
if (addSentinel)
{
domainMap.AddSentinel(newOneOf.RestrictedMemberSlot.MemberPath);
}
atoms.Add(BoolExpression.CreateLiteral(newOneOf, domainMap));
if (addSentinel)
{
domainMap.RemoveSentinel(newOneOf.RestrictedMemberSlot.MemberPath);
}
}
// We create a new whereClause that has the memberDomainMap set
if (atoms.Count > 0)
{
m_whereClause = BoolExpression.CreateAnd(atoms.ToArray());
}
}
/// <summary>
/// Find the Foreign Key Associations that relate EntitySets used in these left cell wrappers and
/// add any equivalence facts between sets implied by 1:1 associations.
/// We can collect other implication facts but we don't have a scenario that needs them( yet ).
/// </summary>
/// <param name="rightKB"></param>
/// <param name="rightDomainMap"></param>
private void CreateConstraintsForForeignKeyAssociationsAffectingThisWarapper(
FragmentQueryKB rightKB, MemberDomainMap rightDomainMap)
{
//First find the entity types of the sets in these cell wrappers.
var entityTypes = m_cellWrappers.Select(it => it.RightExtent).OfType<EntitySet>().Select(it => it.ElementType);
//Get all the foreign key association sets in these entity sets
var allForeignKeyAssociationSets =
m_entityContainerMapping.EdmEntityContainer.BaseEntitySets.OfType<AssociationSet>().Where(it => it.ElementType.IsForeignKey);
//Find all the foreign key associations that have corresponding sets
var oneToOneForeignKeyAssociationsForThisWrapper = allForeignKeyAssociationSets.Select(it => it.ElementType);
//Find all the 1:1 associations from the above list
oneToOneForeignKeyAssociationsForThisWrapper =
oneToOneForeignKeyAssociationsForThisWrapper.Where(
it => (it.AssociationEndMembers.All(endMember => endMember.RelationshipMultiplicity == RelationshipMultiplicity.One)));
//Filter the 1:1 foreign key associations to the ones relating the sets used in these cell wrappers.
oneToOneForeignKeyAssociationsForThisWrapper =
oneToOneForeignKeyAssociationsForThisWrapper.Where(
it => (it.AssociationEndMembers.All(endMember => entityTypes.Contains(endMember.GetEntityType()))));
//filter foreign key association sets to the sets that are 1:1 and affecting this wrapper.
var oneToOneForeignKeyAssociationSetsForThisWrapper =
allForeignKeyAssociationSets.Where(it => oneToOneForeignKeyAssociationsForThisWrapper.Contains(it.ElementType));
//Collect the facts for the foreign key association sets that are 1:1 and affecting this wrapper
foreach (var assocSet in oneToOneForeignKeyAssociationSetsForThisWrapper)
{
rightKB.CreateEquivalenceConstraintForOneToOneForeignKeyAssociation(assocSet, rightDomainMap);
}
}
// effects: Given the extent cells and a map for the domains of all
// variables in it, fixes the cell constant domains of the where
// clauses in the left queries of cells (left is defined using viewTarget)
private static void UpdateWhereClauseForEachCell(
IEnumerable<Cell> extentCells, MemberDomainMap queryDomainMap,
MemberDomainMap updateDomainMap, ConfigViewGenerator config)
{
foreach (var cell in extentCells)
{
cell.CQuery.UpdateWhereClause(queryDomainMap);
cell.SQuery.UpdateWhereClause(updateDomainMap);
}
// Fix enumerable domains - currently it is only applicable to boolean type. Note that it is
// not applicable to enumerated types since we allow any value of the underlying type of the enum type.
queryDomainMap.ReduceEnumerableDomainToEnumeratedValues(config);
updateDomainMap.ReduceEnumerableDomainToEnumeratedValues(config);
}
internal static FragmentQuery CreateMemberConditionQuery(
MemberPath currentPath, Constant domainValue,
IEnumerable<MemberPath> keyAttributes, MemberDomainMap domainMap)
{
// construct WHERE clause for this value
var domainWhereClause = FragmentQuery.CreateMemberCondition(currentPath, domainValue, domainMap);
// get a rewriting for CASE statements by not requesting any attributes beyond key
var attributes = keyAttributes;
if (domainValue is NegatedConstant)
{
// we need the attribute value
attributes = keyAttributes.Concat(new[] { currentPath });
}
return FragmentQuery.Create(attributes, domainWhereClause);
}
private static IEnumerable<MemberPath> GetConditionalScalarMembers(
EdmType edmType, MemberPath currentPath, MemberDomainMap domainMap)
{
return currentPath.GetMembers(edmType, true /* isScalar */, true /* isConditional */, null /* isPartOfKey */, domainMap);
}
/// <summary> /// Fixes the range of the literal using the new values provided in <paramref name="range" /> and returns a boolean expression corresponding to the new value. /// </summary> internal abstract DomainBoolExpr FixRange(Set <Constant> range, MemberDomainMap memberDomainMap);
