// 
// Decompiled by Procyon v0.6.0
// 

package com.google.protobuf;

public final class RpcUtil
{
    private RpcUtil() {
    }
    
    public static <Type extends Message> RpcCallback<Type> specializeCallback(final RpcCallback<Message> originalCallback) {
        return (RpcCallback<Type>)originalCallback;
    }
    
    public static <Type extends Message> RpcCallback<Message> generalizeCallback(final RpcCallback<Type> originalCallback, final Class<Type> originalClass, final Type defaultInstance) {
        return new RpcCallback<Message>() {
            @Override
            public void run(final Message parameter) {
                Type typedParameter;
                try {
                    typedParameter = originalClass.cast(parameter);
                }
                catch (final ClassCastException ignored) {
                    typedParameter = (Type)copyAsType(defaultInstance, parameter);
                }
                originalCallback.run(typedParameter);
            }
        };
    }
    
    private static <Type extends Message> Type copyAsType(final Type typeDefaultInstance, final Message source) {
        return (Type)typeDefaultInstance.newBuilderForType().mergeFrom(source).build();
    }
    
    public static <ParameterType> RpcCallback<ParameterType> newOneTimeCallback(final RpcCallback<ParameterType> originalCallback) {
        return new RpcCallback<ParameterType>() {
            private boolean alreadyCalled = false;
            
            @Override
            public void run(final ParameterType parameter) {
                synchronized (this) {
                    if (this.alreadyCalled) {
                        throw new AlreadyCalledException();
                    }
                    this.alreadyCalled = true;
                }
                originalCallback.run(parameter);
            }
        };
    }
    
    public static final class AlreadyCalledException extends RuntimeException
    {
        private static final long serialVersionUID = 5469741279507848266L;
        
        public AlreadyCalledException() {
            super("This RpcCallback was already called and cannot be called multiple times.");
        }
    }
}