package org.jruby.ir.instructions;
import org.jruby.Ruby;
import org.jruby.RubyModule;
import org.jruby.ir.IRVisitor;
import org.jruby.ir.Operation;
import org.jruby.ir.operands.Operand;
import org.jruby.ir.operands.Variable;
import org.jruby.ir.transformations.inlining.InlinerInfo;
import org.jruby.parser.StaticScope;
import org.jruby.runtime.Block;
import org.jruby.runtime.DynamicScope;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;
import java.util.Map;
// Const search:
// - looks up lexical scopes
// - then inheritance hierarcy if lexical search fails
// - then invokes const_missing if inheritance search fails
public class SearchConstInstr extends Instr implements ResultInstr {
private Operand startingScope;
private String constName;
private boolean noPrivateConsts;
private Variable result;
// Constant caching
private volatile transient Object cachedConstant = null;
private Object generation = -1;
public SearchConstInstr(Variable result, String constName, Operand startingScope, boolean noPrivateConsts) {
super(Operation.SEARCH_CONST);
assert result != null: "SearchConstInstr result is null";
this.result = result;
this.constName = constName;
this.startingScope = startingScope;
this.noPrivateConsts = noPrivateConsts;
}
public Operand[] getOperands() {
return new Operand[] { startingScope };
}
@Override
public void simplifyOperands(Map<Operand, Operand> valueMap, boolean force) {
startingScope = startingScope.getSimplifiedOperand(valueMap, force);
}
public Variable getResult() {
return result;
}
public void updateResult(Variable v) {
this.result = v;
}
public Instr cloneForInlining(InlinerInfo ii) {
return new SearchConstInstr(ii.getRenamedVariable(result), constName, startingScope.cloneForInlining(ii), noPrivateConsts);
}
@Override
public String toString() {
return super.toString() + "(" + constName + ", " + startingScope + ", no-private-consts=" + noPrivateConsts + ")";
}
private Object cache(ThreadContext context, DynamicScope currDynScope, IRubyObject self, Object[] temp, Ruby runtime) {
// Lexical lookup
RubyModule object = runtime.getObject();
StaticScope staticScope = (StaticScope) startingScope.retrieve(context, self, currDynScope, temp);
Object constant = (staticScope == null) ? object.getConstant(constName) : staticScope.getConstantInner(constName);
// Inheritance lookup
RubyModule module = null;
if (constant == null) {
// SSS FIXME: Is this null check case correct?
module = staticScope == null ? object : staticScope.getModule();
constant = noPrivateConsts ? module.getConstantFromNoConstMissing(constName, false) : module.getConstantNoConstMissing(constName);
}
// Call const_missing or cache
if (constant == null) {
constant = module.callMethod(context, "const_missing", context.runtime.fastNewSymbol(constName));
} else {
// recache
generation = runtime.getConstantInvalidator().getData();
cachedConstant = constant;
}
return constant;
}
private boolean isCached(Ruby runtime, Object value) {
return value != null && generation == runtime.getConstantInvalidator().getData();
}
@Override
public Object interpret(ThreadContext context, DynamicScope currDynScope, IRubyObject self, Object[] temp, Block block) {
Ruby runtime = context.runtime;
Object constant = cachedConstant; // Store to temp so it does null out on us mid-stream
if (!isCached(runtime, constant)) constant = cache(context, currDynScope, self, temp, runtime);
return constant;
}
@Override
public void visit(IRVisitor visitor) {
visitor.SearchConstInstr(this);
}
public Operand getStartingScope() {
return startingScope;
}
public String getConstName() {
return constName;
}
public boolean isNoPrivateConsts() {
return noPrivateConsts;
}
}