Class MultiFn

src/jvm/clojure/lang/MultiFn.java:18–586

import java.util.concurrent.locks.ReentrantReadWriteLock;

public class MultiFn extends AFn{
final public IFn dispatchFn;
final public Object defaultDispatchVal;
final public IRef hierarchy;
final String name;
final ReentrantReadWriteLock rw;
volatile IPersistentMap methodTable;
volatile IPersistentMap preferTable;
volatile IPersistentMap methodCache;
volatile Object cachedHierarchy;

static final Var assoc = RT.var("clojure.core", "assoc");
static final Var dissoc = RT.var("clojure.core", "dissoc");
static final Var isa = RT.var("clojure.core", "isa?");
static final Var parents = RT.var("clojure.core", "parents");

public MultiFn(String name, IFn dispatchFn, Object defaultDispatchVal, IRef hierarchy) {
	this.rw = new ReentrantReadWriteLock();
	this.name = name;
	this.dispatchFn = dispatchFn;
	this.defaultDispatchVal = defaultDispatchVal;
	this.methodTable = PersistentHashMap.EMPTY;
	this.methodCache = getMethodTable();
	this.preferTable = PersistentHashMap.EMPTY;
    this.hierarchy = hierarchy;
	cachedHierarchy = null;
}

public MultiFn reset(){
	rw.writeLock().lock();
	try{
		methodTable = methodCache = preferTable = PersistentHashMap.EMPTY;
		cachedHierarchy = null;
		return this;
	}
	finally {
		rw.writeLock().unlock();
	}
}

public MultiFn addMethod(Object dispatchVal, IFn method) {
	rw.writeLock().lock();
	try{
		methodTable = getMethodTable().assoc(dispatchVal, method);
		resetCache();
		return this;
	}
	finally {
		rw.writeLock().unlock();
	}
}

public MultiFn removeMethod(Object dispatchVal) {
	rw.writeLock().lock();
	try
		{
		methodTable = getMethodTable().without(dispatchVal);
		resetCache();