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package io.apicurio.datamodels.openapi.visitors.dereference;
import io.apicurio.datamodels.Library;
import io.apicurio.datamodels.core.models.Document;
import io.apicurio.datamodels.core.models.IReferenceNode;
import io.apicurio.datamodels.core.models.Node;
import io.apicurio.datamodels.core.util.IReferenceResolver;
import io.apicurio.datamodels.core.util.ReferenceResolverChain;
import io.apicurio.datamodels.core.util.VisitorUtil;
import io.apicurio.datamodels.core.visitors.TraverserDirection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import java.util.Set;
/**
* Given a {@link Document}, process its reference strings and attempt to dereference them
* using {@link io.apicurio.datamodels.core.util.IReferenceResolver}. Produce a clone of the original model,
* with the resolved components/definitions attached.
*
* @author Jakub Senko
*/
public class Dereferencer {
private final Document source;
private final IReferenceResolver resolver;
private final boolean strict;
private final Set unresolvable = new HashSet<>();
/**
* Setup the dereferencer execution with default config.
*
* @param source original {@link Document}
*/
public Dereferencer(Document source) {
this(source, ReferenceResolverChain.getInstance(), false);
}
/**
* Setup the dereferencer execution.
*
* @param source original {@link Document}
* @param resolver provide a custom resolver, otherwise the common {@link io.apicurio.datamodels.core.util.ReferenceResolverChain}
* is used.
* @param strict If true, and there are any references that cannot be resolved, raise an exception.
* Defaults to false.
*/
public Dereferencer(Document source, IReferenceResolver resolver, boolean strict) {
this.source = source;
this.resolver = resolver;
this.strict = strict;
}
/**
* Execute the algorithm.
*
* @return dereferenced clone of the source document.
* @throws java.lang.RuntimeException if strict and some references could not be dereferenced
*/
public Document dereference() {
Document clone = Library.cloneDocument(source);
IReferenceManipulationStrategy strategy = null;
switch (clone.getDocumentType()) {
case asyncapi2:
strategy = new Aai20IReferenceManipulationStrategy();
break;
case openapi2:
strategy = new Oas20IReferenceManipulationStrategy();
break;
case openapi3:
strategy = new Oas30IReferenceManipulationStrategy();
break;
default:
throw new RuntimeException("Unknown document type: " + clone.getDocumentType());
}
// Keeps the nodes waiting to be processed (BFS-style)
Queue processQueue = new LinkedList<>();
// start with the whole model
processQueue.add(new Context(null, clone));
// Prevents recursive loops
Map resolvedToLocalMap = new HashMap<>();
for (String ref : strategy.getExistingLocalComponents(clone).keySet()) {
resolvedToLocalMap.put(ref, ref);
}
while (!processQueue.isEmpty()) {
Context item = processQueue.remove();
// Local components
Map localComponents = strategy.getExistingLocalComponents(clone);
// Collect all reference objects in the processed node
ReferenceCollectionVisitor rcv = new ReferenceCollectionVisitor();
VisitorUtil.visitTree(item.node, rcv, TraverserDirection.down);
List referencedNodes = rcv.getReferencedNodes();
// For each reference node ...
for (IReferenceNode node : referencedNodes) {
// skip if already local, this makes sense if we're initially processing the whole Document
if (item.parentRef == null && localComponents.containsKey(node.getReference()))
continue;
// Reference to be resolved
Reference originalRef = new Reference(node.getReference());
Reference resolvedRef = originalRef;
// Attempt to resolve
if(item.parentRef != null && resolvedRef.isRelative()) {
resolvedRef = resolvedRef.withAbsoluteFrom(new Reference(item.parentRef));
}
// if we've already seen the resolved reference, just point to the existing one
// to avoid cycles
if (resolvedToLocalMap.containsKey(resolvedRef.getRef())) {
node.setReference(resolvedToLocalMap.get(resolvedRef.getRef()));
continue;
}
Node resolved = resolver.resolveRef(resolvedRef.getRef(), (Node) node);
// if null keep the reference in an 'unresolvable' set to decide later
if (resolved == null) {
unresolvable.add(node.getReference());
} else {
IReferenceManipulationStrategy.ReferenceAndNode localRef = null;
// try to attach
// repeat in case of name conflict
String name = originalRef.getName();
for (int i = 0; i < Integer.MAX_VALUE; i++) {
if (i > 0)
name = originalRef.getName() + i;
try {
localRef = strategy.attachAsDefinition(clone, name, resolved);
break;
} catch (IllegalArgumentException ex) {
// try a different name
// TODO maybe avoid exceptions?
}
}
if (localRef == null) {
unresolvable.add(node.getReference());
} else {
// success!
// rename the original reference
node.setReference(localRef.getRef());
// add resolved node to processing queue
processQueue.add(new Context(originalRef.getRef(), localRef.getNode()));
// remember, to prevent cycles
resolvedToLocalMap.put(resolvedRef.getRef(), localRef.getRef());
}
}
}
}
// we're done, if strict, throw
if (unresolvable.size() != 0 && strict)
throw new RuntimeException("Could not resolve some references: " + unresolvable);
return clone;
}
public IReferenceResolver getResolver() {
return resolver;
}
public boolean isStrict() {
return strict;
}
/**
* After {@link #dereference()} is executed and strict is false,
*
* @return a possibly non-empty set of unresolved references
*/
public Set getUnresolvableReferences() {
return new HashSet<>(unresolvable);
}
/**
* State for each recursive step
*/
private class Context { // TODO maybe merge with IReferenceManipulationStrategy.ReferenceAndNode}
private String parentRef;
private Node node;
private Context(String parentRef, Node node) {
this.parentRef = parentRef;
this.node = node;
}
@Override
public boolean equals(Object o) { // java.util.Objects are not supported by JSweet
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Context context = (Context) o;
if (parentRef != null ? !parentRef.equals(context.parentRef) : context.parentRef != null)
return false;
return node != null ? node.equals(context.node) : context.node == null;
}
@Override
public int hashCode() {
int result = parentRef != null ? parentRef.hashCode() : 0;
result = 31 * result + (node != null ? node.hashCode() : 0);
return result;
}
}
}