com.signalfx.shaded.fasterxml.jackson.jr.ob.impl.ClassKey Maven / Gradle / Ivy
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package com.signalfx.shaded.fasterxml.jackson.jr.ob.impl;
/**
* Key class, used as an efficient and accurate key
* for locating per-class values from {@link java.util.Map}s.
*
* The reason for having a separate key class instead of
* directly using {@link Class} as key is mostly
* to allow for redefining hashCode method --
* for some strange reason, {@link Class} does not
* redefine {@link Object#hashCode} and thus uses identity
* hash, which is pretty slow. This makes key access using
* {@link Class} unnecessarily slow.
*
* Note: since class is not strictly immutable, caller must
* know what it is doing, if changing field values.
*/
public final class ClassKey
{
private String _className;
private Class _class;
/**
* Additional discriminator flags that may be used to allow
* variations for same class.
*
* @since 2.8
*/
private int _flags;
/**
* Let's cache hash code straight away, since we are
* almost certain to need it.
*/
private int _hashCode;
public ClassKey()
{
_class = null;
_className = null;
_flags = _hashCode = 0;
}
public ClassKey(Class clz, int flags)
{
_class = clz;
_flags = flags;
_className = clz.getName();
_hashCode = _className.hashCode() + flags;
}
public ClassKey with(Class clz, int flags)
{
_class = clz;
_className = clz.getName();
_hashCode = _className.hashCode() + flags;
_flags = flags;
return this;
}
/*
/**********************************************************
/* Standard methods
/**********************************************************
*/
@Override
public boolean equals(Object o)
{
if (o == this) return true;
if (o == null) return false;
if (o.getClass() != getClass()) return false;
ClassKey other = (ClassKey) o;
/* Is it possible to have different Class object for same name + class loader combo?
* Let's assume answer is no: if this is wrong, will need to uncomment following functionality
*/
/*
return (other._flags == _flags)
&& (other._className.equals(_className))
&& (other._class.getClassLoader() == _class.getClassLoader());
*/
return (other._flags == _flags) && (other._class == _class);
}
@Override public int hashCode() { return _hashCode; }
@Override public String toString() { return _className; }
}