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
/** * 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).
/** * 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 /********************************************************** */ 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.
/** * 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; } }