/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.cassandra.cql3.functions;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.script.Bindings;
import javax.script.Compilable;
import javax.script.CompiledScript;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineFactory;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import javax.script.SimpleBindings;
import org.apache.cassandra.cql3.ColumnIdentifier;
import org.apache.cassandra.db.marshal.AbstractType;
import org.apache.cassandra.exceptions.InvalidRequestException;
public class ScriptBasedUDF extends UDFunction
{
static final Map<String, Compilable> scriptEngines = new HashMap<>();
static {
ScriptEngineManager scriptEngineManager = new ScriptEngineManager();
for (ScriptEngineFactory scriptEngineFactory : scriptEngineManager.getEngineFactories())
{
ScriptEngine scriptEngine = scriptEngineFactory.getScriptEngine();
boolean compilable = scriptEngine instanceof Compilable;
if (compilable)
{
logger.info("Found scripting engine {} {} - {} {} - language names: {}",
scriptEngineFactory.getEngineName(), scriptEngineFactory.getEngineVersion(),
scriptEngineFactory.getLanguageName(), scriptEngineFactory.getLanguageVersion(),
scriptEngineFactory.getNames());
for (String name : scriptEngineFactory.getNames())
scriptEngines.put(name, (Compilable) scriptEngine);
}
}
}
private final CompiledScript script;
ScriptBasedUDF(FunctionName name,
List<ColumnIdentifier> argNames,
List<AbstractType<?>> argTypes,
AbstractType<?> returnType,
String language,
String body,
boolean deterministic)
throws InvalidRequestException
{
super(name, argNames, argTypes, returnType, language, body, deterministic);
Compilable scriptEngine = scriptEngines.get(language);
if (scriptEngine == null)
throw new InvalidRequestException(String.format("Invalid language '%s' for function '%s'", language, name));
try
{
this.script = scriptEngine.compile(body);
}
catch (RuntimeException | ScriptException e)
{
logger.info("Failed to compile function '{}' for language {}: ", name, language, e);
throw new InvalidRequestException(
String.format("Failed to compile function '%s' for language %s: %s", name, language, e));
}
}
public ByteBuffer execute(List<ByteBuffer> parameters) throws InvalidRequestException
{
Object[] params = new Object[argTypes.size()];
for (int i = 0; i < params.length; i++)
{
ByteBuffer bb = parameters.get(i);
if (bb != null)
params[i] = argTypes.get(i).compose(bb);
}
try
{
Bindings bindings = new SimpleBindings();
for (int i = 0; i < params.length; i++)
bindings.put(argNames.get(i).toString(), params[i]);
Object result = script.eval(bindings);
if (result == null)
return null;
Class<?> javaReturnType = returnType.getSerializer().getType();
Class<?> resultType = result.getClass();
if (!javaReturnType.isAssignableFrom(resultType))
{
if (result instanceof Number)
{
Number rNumber = (Number) result;
if (javaReturnType == Integer.class)
result = rNumber.intValue();
else if (javaReturnType == Long.class)
result = rNumber.longValue();
else if (javaReturnType == Float.class)
result = rNumber.floatValue();
else if (javaReturnType == Double.class)
result = rNumber.doubleValue();
else if (javaReturnType == BigInteger.class)
{
if (rNumber instanceof BigDecimal)
result = ((BigDecimal)rNumber).toBigInteger();
else if (rNumber instanceof Double || rNumber instanceof Float)
result = new BigDecimal(rNumber.toString()).toBigInteger();
else
result = BigInteger.valueOf(rNumber.longValue());
}
else if (javaReturnType == BigDecimal.class)
// String c'tor of BigDecimal is more accurate than valueOf(double)
result = new BigDecimal(rNumber.toString());
}
}
@SuppressWarnings("unchecked") ByteBuffer r = ((AbstractType) returnType).decompose(result);
return r;
}
catch (RuntimeException | ScriptException e)
{
logger.info("Execution of UDF '{}' failed", name, e);
throw new InvalidRequestException("Execution of user-defined function '" + name + "' failed: " + e);
}
}
}