CompilerUtils.java

/*
 * Licensed 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 com.facebook.presto.util;

import com.facebook.airlift.log.Logger;
import com.facebook.presto.bytecode.ByteCodeTooLargeException;
import com.facebook.presto.bytecode.ClassDefinition;
import com.facebook.presto.bytecode.DynamicClassLoader;
import com.facebook.presto.bytecode.ParameterizedType;
import com.facebook.presto.spi.PrestoException;

import java.lang.invoke.MethodHandle;
import java.time.Instant;
import java.time.format.DateTimeFormatter;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.atomic.AtomicLong;

import static com.facebook.presto.bytecode.BytecodeUtils.toJavaIdentifierString;
import static com.facebook.presto.bytecode.ClassGenerator.classGenerator;
import static com.facebook.presto.bytecode.ParameterizedType.typeFromJavaClassName;
import static com.facebook.presto.spi.StandardErrorCode.GENERATED_BYTECODE_TOO_LARGE;
import static java.time.ZoneOffset.UTC;

public final class CompilerUtils
{
    private static final Logger log = Logger.get(CompilerUtils.class);

    private static final AtomicLong CLASS_ID = new AtomicLong();
    private static final DateTimeFormatter TIMESTAMP_FORMAT = DateTimeFormatter.ofPattern("YYYYMMdd_HHmmss");

    public static final String ERROR_LARGE_BYTECODE = "Query results in large bytecode exceeding the limits imposed by JVM";

    private CompilerUtils() {}

    public static ParameterizedType makeClassName(String baseName, Optional<String> suffix)
    {
        String className = baseName.length() > 100 ? baseName.substring(0, 100) : baseName
                + "_" + suffix.orElseGet(() -> Instant.now().atZone(UTC).format(TIMESTAMP_FORMAT))
                + "_" + CLASS_ID.incrementAndGet();
        return typeFromJavaClassName("com.facebook.presto.$gen." + toJavaIdentifierString(className));
    }

    public static ParameterizedType makeClassName(String baseName)
    {
        return makeClassName(baseName, Optional.empty());
    }

    public static <T> Class<? extends T> defineClass(ClassDefinition classDefinition, Class<T> superType, Map<Long, MethodHandle> callSiteBindings, ClassLoader parentClassLoader)
    {
        return defineClass(classDefinition, superType, new DynamicClassLoader(parentClassLoader, callSiteBindings));
    }

    public static <T> Class<? extends T> defineClass(ClassDefinition classDefinition, Class<T> superType, DynamicClassLoader classLoader)
    {
        log.debug("Defining class: %s", classDefinition.getName());
        try {
            return classGenerator(classLoader).defineClass(classDefinition, superType);
        }
        catch (ByteCodeTooLargeException byteCodeTooLargeException) {
            throw new PrestoException(GENERATED_BYTECODE_TOO_LARGE, ERROR_LARGE_BYTECODE);
        }
    }
}