private Accumulator[] buildExternalFunctions(
final RuleBuildContext context,
final AccumulateDescr accumDescr,
MVELDialect dialect,
Map<String, Declaration> decls,
Map<String, Declaration> sourceOuterDeclr,
BoundIdentifiers boundIds,
boolean readLocalsFromTuple) {
Accumulator[] accumulators;
List<AccumulateFunctionCallDescr> functions = accumDescr.getFunctions();
accumulators = new Accumulator[functions.size()];
// creating the custom array reader
InternalReadAccessor arrayReader = new SelfReferenceClassFieldReader(Object[].class, "this");
int index = 0;
Pattern pattern = (Pattern) context.getDeclarationResolver().peekBuildStack();
for (AccumulateFunctionCallDescr func : functions) {
// build an external function executor
AccumulateFunction function =
context.getConfiguration().getAccumulateFunction(func.getFunction());
if (function == null) {
// might have been imported in the package
function =
context
.getKnowledgeBuilder()
.getPackage()
.getAccumulateFunctions()
.get(func.getFunction());
}
if (function == null) {
context.addError(
new DescrBuildError(
accumDescr,
context.getRuleDescr(),
null,
"Unknown accumulate function: '"
+ func.getFunction()
+ "' on rule '"
+ context.getRuleDescr().getName()
+ "'. All accumulate functions must be registered before building a resource."));
return null;
}
final AnalysisResult analysis =
dialect.analyzeExpression(
context,
accumDescr,
func.getParams().length > 0 ? func.getParams()[0] : "\"\"",
boundIds);
MVELCompilationUnit unit =
dialect.getMVELCompilationUnit(
func.getParams().length > 0 ? func.getParams()[0] : "\"\"",
analysis,
getUsedDeclarations(decls, analysis),
getUsedDeclarations(sourceOuterDeclr, analysis),
null,
context,
"drools",
KnowledgeHelper.class,
readLocalsFromTuple,
MVELCompilationUnit.Scope.CONSTRAINT);
accumulators[index] = new MVELAccumulatorFunctionExecutor(unit, function);
// if there is a binding, create the binding
if (func.getBind() != null) {
if (context
.getDeclarationResolver()
.isDuplicated(context.getRule(), func.getBind(), function.getResultType().getName())) {
if (!func.isUnification()) {
context.addError(
new DescrBuildError(
context.getParentDescr(),
accumDescr,
null,
"Duplicate declaration for variable '"
+ func.getBind()
+ "' in the rule '"
+ context.getRule().getName()
+ "'"));
} else {
Declaration inner =
context.getDeclarationResolver().getDeclaration(context.getRule(), func.getBind());
Constraint c =
new MvelConstraint(
Collections.singletonList(context.getPkg().getName()),
accumDescr.isMultiFunction()
? "this[ " + index + " ] == " + func.getBind()
: "this == " + func.getBind(),
new Declaration[] {inner},
null,
IndexUtil.ConstraintType.EQUAL,
context
.getDeclarationResolver()
.getDeclaration(context.getRule(), func.getBind()),
accumDescr.isMultiFunction()
? new ArrayElementReader(arrayReader, index, function.getResultType())
: new SelfReferenceClassFieldReader(function.getResultType(), "this"),
true);
((MutableTypeConstraint) c).setType(Constraint.ConstraintType.BETA);
pattern.addConstraint(c);
index++;
}
} else {
Declaration declr = pattern.addDeclaration(func.getBind());
if (accumDescr.isMultiFunction()) {
declr.setReadAccessor(
new ArrayElementReader(arrayReader, index, function.getResultType()));
} else {
declr.setReadAccessor(
new SelfReferenceClassFieldReader(function.getResultType(), "this"));
}
}
}
index++;
}
return accumulators;
}
@SuppressWarnings("unchecked")
public RuleConditionElement build(
final RuleBuildContext context, final BaseDescr descr, final Pattern prefixPattern) {
boolean typesafe = context.isTypesafe();
try {
final AccumulateDescr accumDescr = (AccumulateDescr) descr;
if (!accumDescr.hasValidInput()) {
return null;
}
final RuleConditionBuilder builder =
(RuleConditionBuilder) context.getDialect().getBuilder(accumDescr.getInput().getClass());
// create source CE
final RuleConditionElement source = builder.build(context, accumDescr.getInput());
if (source == null) {
return null;
}
MVELDialect dialect = (MVELDialect) context.getDialect();
Map<String, Declaration> decls =
context.getDeclarationResolver().getDeclarations(context.getRule());
Map<String, Declaration> sourceOuterDeclr = source.getOuterDeclarations();
Map<String, Declaration> mergedDecl = new HashMap(decls);
mergedDecl.putAll(sourceOuterDeclr);
Map<String, Class<?>> declarationClasses =
DeclarationScopeResolver.getDeclarationClasses(decls);
declarationClasses.putAll(DeclarationScopeResolver.getDeclarationClasses(sourceOuterDeclr));
BoundIdentifiers boundIds =
new BoundIdentifiers(declarationClasses, context.getKnowledgeBuilder().getGlobals());
boundIds.setDeclarations(mergedDecl);
Accumulator[] accumulators;
final boolean readLocalsFromTuple =
PackageBuilderUtil.isReadLocalsFromTuple(context, accumDescr, source);
if (accumDescr.isExternalFunction()) {
// uses accumulate functions
accumulators =
buildExternalFunctions(
context,
accumDescr,
dialect,
decls,
sourceOuterDeclr,
boundIds,
readLocalsFromTuple);
} else {
// it is a custom accumulate
accumulators =
buildCustomAccumulate(
context,
accumDescr,
dialect,
decls,
sourceOuterDeclr,
boundIds,
readLocalsFromTuple);
}
List<Declaration> requiredDeclarations = new ArrayList<Declaration>();
for (Accumulator acc : accumulators) {
MvelAccumulator mvelAcc = (MvelAccumulator) acc;
Collections.addAll(requiredDeclarations, mvelAcc.getRequiredDeclarations());
}
MVELDialectRuntimeData data =
(MVELDialectRuntimeData)
context.getPkg().getDialectRuntimeRegistry().getDialectData("mvel");
Accumulate accumulate;
if (accumDescr.isMultiFunction()) {
accumulate =
new MultiAccumulate(
source,
requiredDeclarations.toArray(new Declaration[requiredDeclarations.size()]),
accumulators);
int index = 0;
for (Accumulator accumulator : accumulators) {
data.addCompileable(
((MultiAccumulate) accumulate).new Wirer(index++), (MVELCompileable) accumulator);
((MVELCompileable) accumulator).compile(data, context.getRule());
}
} else {
accumulate =
new SingleAccumulate(
source,
requiredDeclarations.toArray(new Declaration[requiredDeclarations.size()]),
accumulators[0]);
data.addCompileable(
((SingleAccumulate) accumulate).new Wirer(), (MVELCompileable) accumulators[0]);
((MVELCompileable) accumulators[0]).compile(data, context.getRule());
}
return accumulate;
} catch (Exception e) {
DialectUtil.copyErrorLocation(e, descr);
context.addError(
new DescrBuildError(
context.getParentDescr(),
descr,
e,
"Unable to build expression for 'accumulate' : " + e.getMessage()));
return null;
} finally {
context.setTypesafe(typesafe);
}
}
public void build(final RuleBuildContext context, String consequenceName) {
// pushing consequence LHS into the stack for variable resolution
context.getBuildStack().push(context.getRule().getLhs());
try {
MVELDialect dialect = (MVELDialect) context.getDialect(context.getDialect().getId());
final RuleDescr ruleDescr = context.getRuleDescr();
String text =
(Rule.DEFAULT_CONSEQUENCE_NAME.equals(consequenceName))
? (String) ruleDescr.getConsequence()
: (String) ruleDescr.getNamedConsequences().get(consequenceName);
text = processMacros(text);
Map<String, Declaration> decls =
context.getDeclarationResolver().getDeclarations(context.getRule());
AnalysisResult analysis =
dialect.analyzeBlock(
context,
context.getRuleDescr(),
dialect.getInterceptors(),
text,
new BoundIdentifiers(
DeclarationScopeResolver.getDeclarationClasses(decls),
context.getPackageBuilder().getGlobals(),
null,
KnowledgeHelper.class),
null,
"drools",
KnowledgeHelper.class);
if (analysis == null) {
// something bad happened, issue already logged in errors
return;
}
final BoundIdentifiers usedIdentifiers = analysis.getBoundIdentifiers();
final Declaration[] declarations = new Declaration[usedIdentifiers.getDeclrClasses().size()];
String[] declrStr = new String[declarations.length];
int j = 0;
for (String str : usedIdentifiers.getDeclrClasses().keySet()) {
declrStr[j] = str;
declarations[j++] = decls.get(str);
}
Arrays.sort(declarations, SortDeclarations.instance);
for (int i = 0; i < declrStr.length; i++) {
declrStr[i] = declarations[i].getIdentifier();
}
context.getRule().setRequiredDeclarationsForConsequence(consequenceName, declrStr);
MVELCompilationUnit unit =
dialect.getMVELCompilationUnit(
text,
analysis,
declarations,
null,
null,
context,
"drools",
KnowledgeHelper.class,
false);
MVELConsequence expr = new MVELConsequence(unit, dialect.getId());
if (Rule.DEFAULT_CONSEQUENCE_NAME.equals(consequenceName)) {
context.getRule().setConsequence(expr);
} else {
context.getRule().addNamedConsequence(consequenceName, expr);
}
MVELDialectRuntimeData data =
(MVELDialectRuntimeData)
context.getPkg().getDialectRuntimeRegistry().getDialectData("mvel");
data.addCompileable(context.getRule(), expr);
expr.compile(data);
} catch (final Exception e) {
copyErrorLocation(e, context.getRuleDescr());
context.addError(
new DescrBuildError(
context.getParentDescr(),
context.getRuleDescr(),
null,
"Unable to build expression for 'consequence': "
+ e.getMessage()
+ " '"
+ context.getRuleDescr().getConsequence()
+ "'"));
}
}