org.jruby.java.dispatch.CallableSelector Maven / Gradle / Ivy
package org.jruby.java.dispatch;
import java.lang.reflect.Member;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import org.jruby.Ruby;
import org.jruby.RubyBignum;
import org.jruby.RubyBoolean;
import org.jruby.RubyFixnum;
import org.jruby.RubyFloat;
import org.jruby.RubyInteger;
import org.jruby.RubyString;
import org.jruby.javasupport.JavaCallable;
import org.jruby.javasupport.JavaClass;
import org.jruby.javasupport.JavaUtil;
import org.jruby.javasupport.ParameterTypes;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.util.collections.IntHashMap;
import static org.jruby.util.CodegenUtils.getBoxType;
import static org.jruby.util.CodegenUtils.prettyParams;
/**
* Method selection logic for calling from Ruby to Java.
*/
public class CallableSelector {
private CallableSelector() { /* no-instances */ }
//private static final boolean DEBUG = true;
@SuppressWarnings("unchecked")
public static ParameterTypes matchingCallableArityN(Ruby runtime, Map cache, ParameterTypes[] methods, IRubyObject[] args) {
final int signatureCode = argsHashCode(args);
ParameterTypes method = (ParameterTypes) cache.get(signatureCode);
if (method == null) {
method = findMatchingCallableForArgs(runtime, methods, args);
if (method != null) cache.put(signatureCode, method);
}
return method;
}
// NOTE: The five match methods are arity-split to avoid the cost of boxing arguments
// when there's already a cached match. Do not condense them into a single
// method.
@SuppressWarnings("unchecked")
public static JavaCallable matchingCallableArityN(Ruby runtime, Map cache, JavaCallable[] methods, IRubyObject[] args) {
final int signatureCode = argsHashCode(args);
JavaCallable method = (JavaCallable) cache.get(signatureCode);
if (method == null) {
method = findMatchingCallableForArgs(runtime, methods, args);
if (method != null) cache.put(signatureCode, method);
}
return method;
}
public static JavaCallable matchingCallableArityOne(Ruby runtime, Map cache, JavaCallable[] methods, IRubyObject arg0) {
final int signatureCode = argsHashCode(arg0);
JavaCallable method = (JavaCallable) cache.get(signatureCode);
if (method == null) {
method = findMatchingCallableForArgs(runtime, methods, arg0);
if (method != null) cache.put(signatureCode, method);
}
return method;
}
public static JavaCallable matchingCallableArityTwo(Ruby runtime, Map cache, JavaCallable[] methods, IRubyObject arg0, IRubyObject arg1) {
final int signatureCode = argsHashCode(arg0, arg1);
JavaCallable method = (JavaCallable) cache.get(signatureCode);
if (method == null) {
method = findMatchingCallableForArgs(runtime, methods, arg0, arg1);
if (method != null) cache.put(signatureCode, method);
}
return method;
}
public static JavaCallable matchingCallableArityThree(Ruby runtime, Map cache, JavaCallable[] methods, IRubyObject arg0, IRubyObject arg1, IRubyObject arg2) {
final int signatureCode = argsHashCode(arg0, arg1, arg2);
JavaCallable method = (JavaCallable) cache.get(signatureCode);
if (method == null) {
method = findMatchingCallableForArgs(runtime, methods, arg0, arg1, arg2);
if (method != null) cache.put(signatureCode, method);
}
return method;
}
public static JavaCallable matchingCallableArityFour(Ruby runtime, Map cache, JavaCallable[] methods, IRubyObject arg0, IRubyObject arg1, IRubyObject arg2, IRubyObject arg3) {
final int signatureCode = argsHashCode(arg0, arg1, arg2, arg3);
JavaCallable method = (JavaCallable) cache.get(signatureCode);
if (method == null) {
method = findMatchingCallableForArgs(runtime, methods, arg0, arg1, arg2, arg3);
if (method != null) cache.put(signatureCode, method);
}
return method;
}
public static T matchingCallableArityN(Ruby runtime, IntHashMap cache, T[] methods, IRubyObject[] args) {
final int signatureCode = argsHashCode(args);
T method = cache.get(signatureCode);
if (method == null) {
method = findMatchingCallableForArgs(runtime, methods, args);
if (method != null) cache.put(signatureCode, method);
}
return method;
}
public static T matchingCallableArityOne(Ruby runtime, IntHashMap cache, T[] methods, IRubyObject arg0) {
final int signatureCode = argsHashCode(arg0);
T method = cache.get(signatureCode);
if (method == null) {
method = findMatchingCallableForArgs(runtime, methods, arg0);
if (method != null) cache.put(signatureCode, method);
}
return method;
}
public static T matchingCallableArityTwo(Ruby runtime, IntHashMap cache, T[] methods, IRubyObject arg0, IRubyObject arg1) {
final int signatureCode = argsHashCode(arg0, arg1);
T method = cache.get(signatureCode);
if (method == null) {
method = findMatchingCallableForArgs(runtime, methods, arg0, arg1);
if (method != null) cache.put(signatureCode, method);
}
return method;
}
public static T matchingCallableArityThree(Ruby runtime, IntHashMap cache, T[] methods, IRubyObject arg0, IRubyObject arg1, IRubyObject arg2) {
final int signatureCode = argsHashCode(arg0, arg1, arg2);
T method = cache.get(signatureCode);
if (method == null) {
method = findMatchingCallableForArgs(runtime, methods, arg0, arg1, arg2);
if (method != null) cache.put(signatureCode, method);
}
return method;
}
public static T matchingCallableArityFour(Ruby runtime, IntHashMap cache, T[] methods, IRubyObject arg0, IRubyObject arg1, IRubyObject arg2, IRubyObject arg3) {
final int signatureCode = argsHashCode(arg0, arg1, arg2, arg3);
T method = cache.get(signatureCode);
if (method == null) {
method = findMatchingCallableForArgs(runtime, methods, arg0, arg1, arg2, arg3);
if (method != null) cache.put(signatureCode, method);
}
return method;
}
private static T findMatchingCallableForArgs(final Ruby runtime,
final T[] methods, final IRubyObject... args) {
T method = null;
// try the new way first
final List candidates = findCallableCandidates(methods, args);
final int size = candidates.size();
if ( size > 0 ) {
// new way found one, so let's go with that
if ( size == 1 ) method = candidates.get(0);
else { // narrow to most specific version (or first version, if none are more specific)
T mostSpecific = candidates.get(0);
Class[] msTypes = mostSpecific.getParameterTypes();
boolean ambiguous = false;
OUTER: for ( int c = 1; c < size; c++ ) {
final T candidate = candidates.get(c);
final Class[] cTypes = candidate.getParameterTypes();
for ( int i = 0; i < msTypes.length; i++ ) {
final Class msType = msTypes[i], cType = cTypes[i];
if ( msType != cType && msType.isAssignableFrom(cType) ) {
mostSpecific = candidate;
msTypes = cTypes;
ambiguous = false; continue OUTER;
}
}
// none more specific; check for ambiguities
for ( int i = 0; i < msTypes.length; i++ ) {
final Class msType = msTypes[i], cType = cTypes[i];
if ( msType == cType || msType.isAssignableFrom(cType) || cType.isAssignableFrom(msType) ) {
ambiguous = false; continue OUTER;
}
else if ( cType.isPrimitive() && msType.isAssignableFrom(getBoxType(cType)) ) {
ambiguous = false; continue OUTER;
}
else {
ambiguous = true;
}
}
// somehow we can still decide e.g. if we got a RubyFixnum
// then (int) constructor shoudl be preffered over (float)
if ( ambiguous ) {
int msPref = 0, cPref = 0;
for ( int i = 0; i < msTypes.length; i++ ) {
final Class msType = msTypes[i], cType = cTypes[i];
msPref += calcTypePreference(msType, args[i]);
cPref += calcTypePreference(cType, args[i]);
}
// for backwards compatibility we do not switch to cType as
// the better fit - we seem to lack tests on this front ...
if ( msPref > cPref ) ambiguous = false; // continue OUTER;
}
}
method = mostSpecific;
if ( ambiguous ) {
runtime.getWarnings().warn("ambiguous Java methods found, using " + ((Member) ((JavaCallable) method).accessibleObject()).getName() + prettyParams(msTypes));
}
}
}
// fall back on old ways
if (method == null) {
method = findCallable(methods, Exact, args);
if (method == null) {
method = findCallable(methods, AssignableAndPrimitivable, args);
if (method == null) {
method = findCallable(methods, AssignableOrDuckable, args);
if (method == null) {
method = findCallable(methods, AssignableOrDuckable, args);
if (method == null) {
method = findCallable(methods, AssignableAndPrimitivableWithVarargs, args);
}
}
}
}
}
return method;
}
private static T findCallable(T[] callables, CallableAcceptor acceptor, IRubyObject[] args) {
T bestCallable = null;
int bestScore = -1;
for ( int i = 0; i < callables.length; i++ ) {
final T callable = callables[i];
if ( acceptor.accept(callable, args) ) {
int currentScore = calcExactnessScore(callable, args);
if (currentScore > bestScore) {
bestCallable = callable; bestScore = currentScore;
}
}
}
return bestCallable;
}
@SuppressWarnings("unchecked")
private static List findCallableCandidates(final T[] callables,
final IRubyObject[] args) {
// in case of an exact match prefer to return it early :
for ( int c = 0; c < callables.length; c++ ) {
final T callable = callables[c];
if ( exactMatch(callable, args ) ) return Collections.singletonList(callable);
}
final ArrayList retained = new ArrayList(callables.length);
ParameterTypes[] incoming = callables.clone();
for ( int i = 0; i < args.length; i++ ) {
retained.clear();
for ( final Matcher matcher : NON_EXACT_MATCH_SEQUENCE ) {
for ( int c = 0; c < incoming.length; c++ ) {
ParameterTypes callable = incoming[c];
if ( callable == null ) continue; // removed (matched)
Class[] types = callable.getParameterTypes();
if ( matcher.match( types[i], args[i] ) ) {
retained.add((T) callable);
incoming[c] = null; // retaining - remove
}
}
}
incoming = retained.toArray( new ParameterTypes[retained.size()] );
}
return retained;
}
private static int calcExactnessScore(final ParameterTypes callable, final IRubyObject[] args) {
final Class[] types = callable.getParameterTypes();
int count = 0;
if ( callable.isVarArgs() ) {
// varargs exactness gives the last N args as +1 since they'll already
// have been determined to fit
// dig out as many trailing args as possible that match varargs type
final int nonVarargs = types.length - 1;
count += 1; // add one for vararg
// check remaining args
for (int i = 0; i < nonVarargs && i < args.length; i++) {
if ( types[i] == getJavaClass(args[i]) ) count++;
}
}
else {
for (int i = 0; i < args.length; i++) {
if ( types[i] == getJavaClass(args[i]) ) count++;
}
}
return count;
}
private static interface CallableAcceptor {
public boolean accept(ParameterTypes types, IRubyObject[] args);
}
private static final CallableAcceptor Exact = new CallableAcceptor() {
public boolean accept(ParameterTypes types, IRubyObject[] args) {
return exactMatch(types, args);
}
};
private static final CallableAcceptor AssignableAndPrimitivable = new CallableAcceptor() {
public boolean accept(ParameterTypes types, IRubyObject[] args) {
return assignableAndPrimitivable(types, args);
}
};
private static final CallableAcceptor AssignableOrDuckable = new CallableAcceptor() {
public boolean accept(ParameterTypes types, IRubyObject[] args) {
return assignableOrDuckable(types, args);
}
};
private static final CallableAcceptor AssignableAndPrimitivableWithVarargs = new CallableAcceptor() {
public boolean accept(ParameterTypes types, IRubyObject[] args) {
return assignableAndPrimitivableWithVarargs(types, args);
}
};
private static interface Matcher {
public boolean match(final Class type, final IRubyObject arg);
}
private static final Matcher EXACT = new Matcher() {
public boolean match(final Class type, final IRubyObject arg) {
final Class argClass = getJavaClass(arg);
return type == argClass || (type.isPrimitive() && getBoxType(type) == argClass);
}
@Override public String toString() { return "EXACT"; } // for debugging
};
private static final Matcher ASSIGNABLE = new Matcher() {
public boolean match(Class type, IRubyObject arg) {
return assignable(type, arg);
}
@Override public String toString() { return "ASSIGNABLE"; } // for debugging
};
private static final Matcher PRIMITIVABLE = new Matcher() {
public boolean match(Class type, IRubyObject arg) {
return primitivable(type, arg);
}
@Override public String toString() { return "PRIMITIVABLE"; } // for debugging
};
private static final Matcher DUCKABLE = new Matcher() {
public boolean match(Class type, IRubyObject arg) {
return duckable(type, arg);
}
@Override public String toString() { return "DUCKABLE"; } // for debugging
};
//private static final Matcher[] MATCH_SEQUENCE = new Matcher[] { EXACT, PRIMITIVABLE, ASSIGNABLE, DUCKABLE };
private static final Matcher[] NON_EXACT_MATCH_SEQUENCE = new Matcher[] { PRIMITIVABLE, ASSIGNABLE, DUCKABLE };
private static boolean exactMatch(ParameterTypes paramTypes, IRubyObject... args) {
Class[] types = paramTypes.getParameterTypes();
if (args.length != types.length) return false;
for (int i = 0; i < types.length; i++) {
if (!EXACT.match(types[i], args[i])) {
return false;
}
}
return true;
}
private static boolean assignableAndPrimitivable(ParameterTypes paramTypes, IRubyObject... args) {
Class[] types = paramTypes.getParameterTypes();
if (args.length != types.length) return false;
for (int i = 0; i < types.length; i++) {
if (!(ASSIGNABLE.match(types[i], args[i]) && PRIMITIVABLE.match(types[i], args[i]))) {
return false;
}
}
return true;
}
private static boolean assignableOrDuckable(ParameterTypes paramTypes, IRubyObject... args) {
Class[] types = paramTypes.getParameterTypes();
if (args.length != types.length) return false;
for (int i = 0; i < types.length; i++) {
if (!(ASSIGNABLE.match(types[i], args[i]) || DUCKABLE.match(types[i], args[i]))) {
return false;
}
}
return true;
}
private static boolean assignableAndPrimitivableWithVarargs(ParameterTypes paramTypes, IRubyObject... args) {
// bail out if this is not a varargs method
if (!paramTypes.isVarArgs()) return false;
Class[] types = paramTypes.getParameterTypes();
Class varArgArrayType = types[types.length - 1];
Class varArgType = varArgArrayType.getComponentType();
// if there's no args, we only match when there's just varargs
if ( args.length == 0 ) return types.length <= 1;
// dig out as many trailing args as will fit, ensuring they match varargs type
int nonVarargs = types.length - 1;
for (int i = args.length - 1; i >= nonVarargs; i--) {
if (!(ASSIGNABLE.match(varArgType, args[i]) || PRIMITIVABLE.match(varArgType, args[i]))) {
return false;
}
}
// check remaining args
for (int i = 0; i < nonVarargs; i++) {
if (!(ASSIGNABLE.match(types[i], args[i]) || PRIMITIVABLE.match(types[i], args[i]))) {
return false;
}
}
return true;
}
private static boolean assignable(Class type, final IRubyObject arg) {
return JavaClass.assignable(type, getJavaClass(arg));
}
/**
* This method checks whether an argument can be *directly* converted into
* the target primitive, i.e. without changing from integral to floating-point.
*
* @param type The target type
* @param arg The argument to convert
* @return Whether the argument can be directly converted to the target primitive type
*/
private static boolean primitivable(final Class type, final IRubyObject arg) {
final Class argClass = getJavaClass(arg);
if (type.isPrimitive()) {
// TODO: This is where we would want to do precision checks to see
// if it's non-destructive to coerce a given type into the target
// integral primitive
if (type == Integer.TYPE || type == Long.TYPE || type == Short.TYPE || type == Character.TYPE) {
return argClass == long.class || // long first because it's what Fixnum claims to be
argClass == byte.class ||
argClass == short.class ||
argClass == char.class ||
argClass == int.class ||
argClass == Long.class ||
argClass == Byte.class ||
argClass == Short.class ||
argClass == Character.class ||
argClass == Integer.class;
}
if (type == Float.TYPE || type == Double.TYPE) {
return argClass == double.class || // double first because it's what float claims to be
argClass == float.class ||
argClass == Float.class ||
argClass == Double.class;
}
if (type == Boolean.TYPE) {
return argClass == boolean.class ||
argClass == Boolean.class;
}
}
return false;
}
private static int calcTypePreference(Class type, final IRubyObject arg) {
final boolean primitive = type.isPrimitive();
if ( primitive ) type = getBoxType(type);
if ( Number.class.isAssignableFrom(type) || Character.class == type ) {
if ( arg instanceof RubyFixnum ) {
if ( type == Long.class ) return 10;
if ( type == Integer.class ) return 8;
if ( type == BigInteger.class ) return 7;
if ( type == Short.class ) return 6;
if ( type == Byte.class ) return 4;
if ( type == Float.class ) return 3;
if ( type == Double.class ) return 2;
//if ( type == Character.class ) return 1;
return 1;
}
if ( arg instanceof RubyBignum ) {
if ( type == BigInteger.class ) return 10;
if ( type == Long.class ) return 4;
//if ( type == Integer.class ) return 6;
//if ( type == Short.class ) return 5;
//if ( type == Byte.class ) return 4;
if ( type == Double.class ) return 6;
if ( type == Float.class ) return 5;
//if ( type == Character.class ) return 1;
return 1;
}
if ( arg instanceof RubyInteger ) {
if ( type == Long.class ) return 10;
if ( type == Integer.class ) return 8;
//if ( type == Short.class ) return 6;
//if ( type == Byte.class ) return 4;
if ( type == Float.class ) return 3;
if ( type == Double.class ) return 2;
//if ( type == Character.class ) return 1;
return 1;
}
if ( arg instanceof RubyFloat ) {
if ( type == Double.class ) return 10;
if ( type == Float.class ) return 8;
if ( type == BigDecimal.class ) return 6;
if ( type == Long.class ) return 4;
if ( type == Integer.class ) return 3;
if ( type == Short.class ) return 2;
//if ( type == Character.class ) return 1;
return 1;
}
}
else if ( arg instanceof RubyString ) {
if ( type == String.class ) return 10;
if ( type == byte[].class ) return 8;
if ( CharSequence.class.isAssignableFrom(type) ) return 7;
if ( type == Character.class ) return 1;
}
else if ( arg instanceof RubyBoolean ) {
if ( type == Boolean.class ) return 10;
//if ( type == Byte.class ) return 2;
//if ( type == Character.class ) return 1;
}
return 0;
}
private static boolean duckable(final Class type, final IRubyObject arg) {
return JavaUtil.isDuckTypeConvertable(getJavaClass(arg), type);
}
private static int argsHashCode(IRubyObject a0) {
return 31 + javaClassHashCode(a0);
}
private static int argsHashCode(IRubyObject a0, IRubyObject a1) {
return 31 * argsHashCode(a0) + javaClassHashCode(a1);
}
private static int argsHashCode(IRubyObject a0, IRubyObject a1, IRubyObject a2) {
return 31 * argsHashCode(a0, a1) + javaClassHashCode(a2);
}
private static int argsHashCode(IRubyObject a0, IRubyObject a1, IRubyObject a2, IRubyObject a3) {
return 31 * argsHashCode(a0, a1, a2) + javaClassHashCode(a3);
}
private static int argsHashCode(IRubyObject[] args) {
if ( args == null ) return 0;
int result = 1;
for ( int i = 0; i < args.length; i++ ) {
result = 31 * result + javaClassHashCode(args[i]);
}
return result;
}
private static int javaClassHashCode(final IRubyObject arg) {
return arg == null ? 0 : arg.getJavaClass().hashCode();
}
private static Class getJavaClass(final IRubyObject arg) {
return arg != null ? arg.getJavaClass() : void.class;
}
/**
* Internal helper to allocate a callable map to cache argument method matches.
* @param the callable type
* @return cache usable with {@link CallableSelector}
*/
public static IntHashMap newCallableCache() {
return new IntHashMap(8);
}
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