Sample OpenHFT import using spring boot

OpenHFTImport.java

package me.grison.openhft.foo;

import net.openhft.collections.SharedHashMap;
import net.openhft.collections.SharedHashMapBuilder;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

import java.io.File;
import java.util.UUID;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

@ComponentScan
@Configuration
@SpringBootApplication
@EnableAutoConfiguration
public class OpenHFTMassImport {
	@Bean
	CommandLineRunner init() {
		return args -> {
			SharedHashMap<String, String> map = new SharedHashMapBuilder()
					.create(File.createTempFile("mass-import", "foo"), String.class, String.class);
			int numKeys = 1_000_000;
			int availableProcessors = Runtime.getRuntime().availableProcessors() * 4;
			ExecutorService exec = Executors.newFixedThreadPool(availableProcessors);

			// pre-compute UUIDs
			String[] uuids = new String[numKeys];
			for (int i = 0; i < numKeys; ++i)
				uuids[i] = UUID.randomUUID().toString();

			// split
			final int portion = numKeys / availableProcessors;
			long time = System.nanoTime();

			for (int i = 0; i < availableProcessors; ++i) {
				final int threadId = i;
				exec.submit(() -> {
					// throw the data at OpenHFT
					for (int j = threadId * portion; j < (threadId + 1) * portion; ++j)
						map.put(uuids[j], uuids[j]);
				});
			}
			exec.shutdown();
			try {
				exec.awaitTermination(Long.MAX_VALUE, TimeUnit.SECONDS);

				long endTime = System.nanoTime();
				System.out.println("\tTook " + (endTime - time) + "ns to execute.");
			} catch (InterruptedException e) {
				System.err.println("Execution interrupted: " + e.getMessage());
			}
		};
	}


	public static void main(String[] args) {
		SpringApplication.run(OpenHFTMassImport.class, args);
	}
}