Calling Fluency from C using GraalVM:SubstrateVM

Command.txt

$ javac -cp fluency-1.9.0-SNAPSHOT-shadow.jar org/komamitsu/fluencycaller/FluencyCaller.java
$ native-image --class-path fluency-1.9.0-SNAPSHOT-shadow.jar:. --shared -H:Name=libfluency --verbose
$ cc -Wall -I. -L. -lfluency main.c
$ ./a.out

FluencyCaller.java

package org.komamitsu.fluencycaller;

import org.graalvm.nativeimage.IsolateThread;
import org.graalvm.nativeimage.c.function.CEntryPoint;
import org.graalvm.nativeimage.c.type.CCharPointer;
import org.graalvm.nativeimage.c.type.CTypeConversion;
import org.komamitsu.fluency.Fluency;

import java.io.IOException;

public class FluencyCaller
{
    private static Fluency fluency;


    @CEntryPoint(name = "init")
     public static void init(IsolateThread isolateThread, CCharPointer host, int port)
            throws IOException
    {
        if (fluency != null) {
            throw new IllegalStateException("The Fluency instance is already created");
        }

        fluency = Fluency.defaultFluency(CTypeConversion.toJavaString(host), port);
    }

    @CEntryPoint(name = "emit")
    public static void emit(IsolateThread isolateThread, CCharPointer tag, CCharPointer msgpackedData, int dataLen)
            throws IOException
    {
        byte[] bytes = new byte[dataLen];
        for (int i = 0; i < bytes.length; i++) {
            bytes[i] = msgpackedData.read(i);
        }

        fluency.emit(CTypeConversion.toJavaString(tag), bytes, 0, dataLen);
    }


    @CEntryPoint(name = "flush")
    public static void flush(IsolateThread isolateThread)
            throws IOException
    {
        if (fluency == null) {
            throw new IllegalStateException("The Fluency instance isn't created");
        }
        fluency.flush();
    }

    @CEntryPoint(name = "close")
    public static void close(IsolateThread isolateThread)
            throws IOException
    {
        if (fluency == null) {
            throw new IllegalStateException("The Fluency instance isn't created");
        }
        fluency.close();
    }
}

main.c

#include <stdio.h>
#include <stdlib.h>
#include <libfluency.h>

int main(void)
{
    int ret;
    graal_create_isolate_params_t isolate_params;
    graal_isolate_t* isolate;

    ret = graal_create_isolate(&isolate_params, &isolate);
    if (ret != 0) {
        fprintf(stderr, "graal_create_isolate: %d\n", ret);
        exit(1);
    }

    init(graal_current_thread(isolate), "127.0.0.1", 24224);

    printf("init finished\n");

    char data[] = {130, 164, 110, 97, 109, 101, 169, 107, 111, 109, 97, 109, 105, 116, 115, 117, 163, 97, 103, 101, 43};
    emit(graal_current_thread(isolate), "foodb.bartbl", data, sizeof(data)/sizeof(data[0]));

    printf("emit finished (size: %d)\n", sizeof(data)/sizeof(data[0]));

    close(graal_current_thread(isolate));
    printf("close finished\n");

    ret = graal_tear_down_isolate(isolate);
    if (ret != 0) {
        fprintf(stderr, "graal_tear_down_isolate: %d\n", ret);
        exit(1);
    }

    return 0;
}