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package com.fasterxml.jackson.jaxrs.cfg;
import java.lang.annotation.Annotation;
/**
* Helper class used to allow efficient caching of information,
* given a sequence of Annotations.
* This is mostly used for reusing introspected information on
* JAX-RS end points.
*
* @since 2.2
*/
public final class AnnotationBundleKey
{
private final static Annotation[] NO_ANNOTATIONS = new Annotation[0];
private final Annotation[] _annotations;
/**
* We also seem to need the type as part of the key (as per [Issue#11]);
* hopefully that and annotations are enough (if not, may need to reconsider
* the way caching is done, and possibly only cache derivation of annotations,
* not mapper or reader/writer).
*/
private final Class _type;
private final boolean _annotationsCopied;
private final int _hashCode;
/*
/**********************************************************
/* Construction
/**********************************************************
*/
/**
* @deprecated Since 2.2.2: use variant that takes explicit Class
*/
@Deprecated
public AnnotationBundleKey(Annotation[] annotations)
{
// could use a private inner class, but this'll do for now; no one should call anyway
this(annotations, AnnotationBundleKey.class);
}
public AnnotationBundleKey(Annotation[] annotations, Class type)
{
_type = type;
// getting hash of name is faster than Class.hashCode() just because latter uses system identity hash:
final int typeHash = type.getName().hashCode();
if (annotations == null || annotations.length == 0) {
annotations = NO_ANNOTATIONS;
_annotationsCopied = true;
_hashCode = typeHash;
} else {
_annotationsCopied = false;
_hashCode = calcHash(annotations) ^ typeHash;
}
_annotations = annotations;
}
private AnnotationBundleKey(Annotation[] annotations, Class type, int hashCode)
{
_annotations = annotations;
_annotationsCopied = true;
_type = type;
_hashCode = hashCode;
}
private final static int calcHash(Annotation[] annotations)
{
/* hmmh. Can't just base on Annotation type; chances are that Annotation
* instances use identity hash, which has to do.
*/
final int len = annotations.length;
int hash = len;
for (int i = 0; i < len; ++i) {
hash = (hash * 31) + annotations[i].hashCode();
}
return hash;
}
/**
* Method called to create a safe immutable copy of the key; used when
* adding entry with this key -- lookups are ok without calling the method.
*/
public AnnotationBundleKey immutableKey() {
if (_annotationsCopied) {
return this;
}
int len = _annotations.length;
Annotation[] newAnnotations = new Annotation[len];
System.arraycopy(_annotations, 0, newAnnotations, 0, len);
return new AnnotationBundleKey(newAnnotations, _type, _hashCode);
}
/*
/**********************************************************
/* Overridden methods
/**********************************************************
*/
@Override
public int hashCode() {
return _hashCode;
}
@Override
public String toString() {
return "[Annotations: "+_annotations.length+", type: "
+_type.getName()+", hash 0x"+Integer.toHexString(_hashCode)
+", copied: "+_annotationsCopied+"]";
}
@Override
public boolean equals(Object o)
{
if (o == this) return true;
if (o == null) return false;
if (o.getClass() != getClass()) return false;
AnnotationBundleKey other = (AnnotationBundleKey) o;
if ((other._hashCode != _hashCode) || (other._type != _type)) {
return false;
}
return _equals(other._annotations);
}
private final boolean _equals(Annotation[] otherAnn)
{
final int len = _annotations.length;
if (otherAnn.length != len) {
return false;
}
for (int i = 0; i < len; ++i) {
if (_annotations[i] != otherAnn[i]) {
return false;
}
}
return true;
}
}