// Copyright (c) Vitaliy Filippov, 2019+
// License: VNPL-1.1 or GNU GPL-2.0+ (see README.md for details)

// FIO engine to test Blockstore through Secondary OSD interface
//
// Prepare storage like in fio_engine.cpp, then start OSD with ./osd, then test it
//
// Random write:
//
// fio -thread -ioengine=./libfio_sec_osd.so -name=test -bs=4k -direct=1 -fsync=16 -iodepth=16 -rw=randwrite \
//     -host=127.0.0.1 -port=11203 [-block_size_order=17] [-single_primary=1] -size=1000M
//
// Linear write:
//
// fio -thread -ioengine=./libfio_sec_osd.so -name=test -bs=128k -direct=1 -fsync=32 -iodepth=32 -rw=write \
//     -host=127.0.0.1 -port=11203 -size=1000M
//
// Random read (run with -iodepth=32 or -iodepth=1):
//
// fio -thread -ioengine=./libfio_sec_osd.so -name=test -bs=4k -direct=1 -iodepth=32 -rw=randread \
//     -host=127.0.0.1 -port=11203 -size=1000M

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>

#include <vector>
#include <unordered_map>

#include "addr_util.h"
#include "epoll_manager.h"
#include "ringloop.h"
#include "messenger.h"
#include "osd_ops.h"
#include "fio_headers.h"

struct sec_data
{
    epoll_manager_t *epmgr;
    ring_loop_t *ringloop;
    osd_messenger_t *msgr;
    ring_consumer_t looper;
    void *bitmap_buf;
    int connect_fd;
    uint64_t op_id;
    /* block_size = 1 << block_order (128KB by default) */
    uint64_t block_order = 17, block_size = 1 << 17;
    bool last_sync = false;
    /* The list of completed io_u structs. */
    std::vector<io_u*> completed;
    uint64_t op_n = 0, inflight = 0;
};

struct sec_options
{
    int __pad;
    char *host = NULL;
    int port = 0;
    int single_primary = 0;
    int trace = 0;
    int block_order = 17;
};

static struct fio_option options[] = {
    {
        .name   = "host",
        .lname  = "Test Secondary OSD host",
        .type   = FIO_OPT_STR_STORE,
        .off1   = offsetof(struct sec_options, host),
        .help   = "Test Secondary OSD host",
        .category = FIO_OPT_C_ENGINE,
        .group  = FIO_OPT_G_FILENAME,
    },
    {
        .name   = "port",
        .lname  = "Test Secondary OSD port",
        .type   = FIO_OPT_INT,
        .off1   = offsetof(struct sec_options, port),
        .help   = "Test Secondary OSD port",
        .category = FIO_OPT_C_ENGINE,
        .group  = FIO_OPT_G_FILENAME,
    },
    {
        .name   = "block_size_order",
        .lname  = "Blockstore block size order",
        .type   = FIO_OPT_INT,
        .off1   = offsetof(struct sec_options, block_order),
        .help   = "Blockstore block size order (size = 2^order)",
        .category = FIO_OPT_C_ENGINE,
        .group  = FIO_OPT_G_FILENAME,
    },
    {
        .name   = "single_primary",
        .lname  = "Single Primary",
        .type   = FIO_OPT_BOOL,
        .off1   = offsetof(struct sec_options, single_primary),
        .help   = "Test single Primary OSD (one PG) instead of Secondary",
        .def    = "0",
        .category = FIO_OPT_C_ENGINE,
        .group  = FIO_OPT_G_FILENAME,
    },
    {
        .name   = "osd_trace",
        .lname  = "OSD trace",
        .type   = FIO_OPT_BOOL,
        .off1   = offsetof(struct sec_options, trace),
        .help   = "Trace OSD operations",
        .def    = "0",
        .category = FIO_OPT_C_ENGINE,
        .group  = FIO_OPT_G_FILENAME,
    },
    {
        .name = NULL,
    },
};

static int sec_setup(struct thread_data *td)
{
    sec_data *bsd;

    bsd = new sec_data;
    if (!bsd)
    {
        td_verror(td, errno, "calloc");
        return 1;
    }
    td->io_ops_data = bsd;

    if (!td->files_index)
    {
        add_file(td, "bs_sec_osd", 0, 0);
        td->o.nr_files = td->o.nr_files ? : 1;
        td->o.open_files++;
    }

    return 0;
}

static void sec_cleanup(struct thread_data *td)
{
    sec_data *bsd = (sec_data*)td->io_ops_data;
    if (bsd)
    {
        delete bsd->msgr;
        delete bsd->epmgr;
        delete bsd->ringloop;
        free(bsd->bitmap_buf);
        close(bsd->connect_fd);
        delete bsd;
    }
}

/* Connect to the server from each thread. */
static int sec_init(struct thread_data *td)
{
    sec_options *o = (sec_options*)td->eo;
    sec_data *bsd = (sec_data*)td->io_ops_data;
    bsd->block_order = o->block_order == 0 ? 17 : o->block_order;
    bsd->block_size = 1 << o->block_order;

    sockaddr addr;
    if (!string_to_addr(std::string(o->host ? o->host : "127.0.0.1"), false, o->port > 0 ? o->port : 11203, &addr))
    {
        fprintf(stderr, "server address: %s is not valid\n", o->host ? o->host : "127.0.0.1");
        return 1;
    }

    bsd->connect_fd = socket(addr.sa_family, SOCK_STREAM, 0);
    if (bsd->connect_fd < 0)
    {
        perror("socket");
        return 1;
    }
    if (connect(bsd->connect_fd, (sockaddr*)&addr, sizeof(addr)) < 0)
    {
        perror("connect");
        return 1;
    }
    int one = 1;
    setsockopt(bsd->connect_fd, SOL_TCP, TCP_NODELAY, &one, sizeof(one));

    fcntl(bsd->connect_fd, F_SETFL, fcntl(bsd->connect_fd, F_GETFL, 0) | O_NONBLOCK);

    json11::Json cfg = json11::Json::object{ { "use_rdma", 0 } };

    bsd->bitmap_buf = malloc(4096);

    bsd->ringloop = new ring_loop_t(512);
    bsd->epmgr = new epoll_manager_t(bsd->ringloop);
    bsd->msgr = new osd_messenger_t();
    bsd->msgr->tfd = bsd->epmgr->tfd;
    bsd->msgr->ringloop = bsd->ringloop;
    bsd->msgr->repeer_pgs = [](osd_num_t){};
    bsd->msgr->parse_config(cfg);
    bsd->msgr->init();

    bsd->looper.loop = [bsd]()
    {
        bsd->msgr->read_requests();
        bsd->msgr->send_replies();
        bsd->ringloop->submit();
    };
    bsd->ringloop->register_consumer(&bsd->looper);

    int peer_fd = bsd->connect_fd;
    bsd->msgr->clients[peer_fd] = new osd_client_t();
    bsd->msgr->clients[peer_fd]->peer_addr = addr;
    bsd->msgr->clients[peer_fd]->peer_port = ntohs(((sockaddr_in*)&addr)->sin_port);
    bsd->msgr->clients[peer_fd]->peer_fd = peer_fd;
    bsd->msgr->clients[peer_fd]->peer_state = PEER_CONNECTED;
    bsd->msgr->clients[peer_fd]->connect_timeout_id = -1;
    bsd->msgr->clients[peer_fd]->osd_num = 1;
    bsd->msgr->clients[peer_fd]->in_buf = malloc_or_die(bsd->msgr->receive_buffer_size);
    bsd->epmgr->tfd->set_fd_handler(peer_fd, true, [msgr = bsd->msgr](int peer_fd, int epoll_events)
    {
        // Either OUT (connected) or HUP
        msgr->handle_peer_epoll(peer_fd, epoll_events);
    });
    bsd->msgr->osd_peer_fds[1] = peer_fd;

    // FIXME: read config (block size) from OSD

    return 0;
}

/* Begin read or write request. */
static enum fio_q_status sec_queue(struct thread_data *td, struct io_u *io)
{
    sec_options *opt = (sec_options*)td->eo;
    sec_data *bsd = (sec_data*)td->io_ops_data;
    int n = bsd->op_n;

    fio_ro_check(td, io);
    if (io->ddir == DDIR_SYNC && bsd->last_sync)
    {
        return FIO_Q_COMPLETED;
    }

    io->engine_data = bsd;

    osd_op_t *oo = new osd_op_t();
    oo->op_type = OSD_OP_OUT;
    oo->peer_fd = bsd->connect_fd;

    osd_any_op_t & op = oo->req;

    op.hdr.magic = SECONDARY_OSD_OP_MAGIC;
    op.hdr.id = n;
    switch (io->ddir)
    {
    case DDIR_READ:
        if (!opt->single_primary)
        {
            op.hdr.opcode = OSD_OP_SEC_READ;
            op.sec_rw.oid = {
                .inode = 1,
                .stripe = io->offset >> bsd->block_order,
            };
            op.sec_rw.version = UINT64_MAX; // last unstable
            op.sec_rw.offset = io->offset % bsd->block_size;
            op.sec_rw.len = io->xfer_buflen;
            op.sec_rw.attr_len = 4;
            oo->bitmap = bsd->bitmap_buf;
            oo->bitmap_len = 4;
        }
        else
        {
            op.hdr.opcode = OSD_OP_READ;
            op.rw.inode = 1;
            op.rw.offset = io->offset;
            op.rw.len = io->xfer_buflen;
        }
        oo->iov.push_back(io->xfer_buf, io->xfer_buflen);
        bsd->last_sync = false;
        break;
    case DDIR_WRITE:
        if (!opt->single_primary)
        {
            op.hdr.opcode = OSD_OP_SEC_WRITE;
            op.sec_rw.oid = {
                .inode = 1,
                .stripe = io->offset >> bsd->block_order,
            };
            op.sec_rw.version = 0; // assign automatically
            op.sec_rw.offset = io->offset % bsd->block_size;
            op.sec_rw.len = io->xfer_buflen;
        }
        else
        {
            op.hdr.opcode = OSD_OP_WRITE;
            op.rw.inode = 1;
            op.rw.offset = io->offset;
            op.rw.len = io->xfer_buflen;
        }
        oo->iov.push_back(io->xfer_buf, io->xfer_buflen);
        bsd->last_sync = false;
        break;
    case DDIR_SYNC:
        if (!opt->single_primary)
        {
            // Allowed only for testing: sync & stabilize all unstable object versions
            op.hdr.opcode = OSD_OP_TEST_SYNC_STAB_ALL;
        }
        else
        {
            op.hdr.opcode = OSD_OP_SYNC;
        }
        // fio sends 32 syncs with -fsync=32. we omit 31 of them even though
        // generally it may not be 100% correct (FIXME: fix fio itself)
        bsd->last_sync = true;
        break;
    default:
        io->error = EINVAL;
        return FIO_Q_COMPLETED;
    }

    oo->callback = [td, io](osd_op_t *oo)
    {
        sec_options *opt = (sec_options*)td->eo;
        sec_data *bsd = (sec_data*)td->io_ops_data;
        if (opt->trace)
        {
            printf("--- %s # %ld %ld\n", io->ddir == DDIR_READ ? "READ" :
                (io->ddir == DDIR_WRITE ? "WRITE" : "SYNC"), oo->reply.hdr.id, oo->reply.hdr.retval);
        }
        io->error = oo->reply.hdr.retval < 0 ? -oo->reply.hdr.retval : 0;
        bsd->completed.push_back(io);
        delete oo;
    };
    bsd->msgr->outbox_push(oo);

    if (opt->trace)
    {
        printf("+++ %s # %d\n", io->ddir == DDIR_READ ? "READ" :
            (io->ddir == DDIR_WRITE ? "WRITE" : "SYNC"), n);
    }

    io->error = 0;
    bsd->inflight++;
    bsd->op_n++;

    if (io->error != 0)
        return FIO_Q_COMPLETED;
    return FIO_Q_QUEUED;
}

static int sec_getevents(struct thread_data *td, unsigned int min, unsigned int max, const struct timespec *t)
{
    sec_data *bsd = (sec_data*)td->io_ops_data;
    while (bsd->completed.size() < min)
    {
        bsd->ringloop->loop();
        if (bsd->completed.size() >= min)
            break;
        bsd->ringloop->wait();
    }
    return bsd->completed.size();
}

static struct io_u *sec_event(struct thread_data *td, int event)
{
    sec_data *bsd = (sec_data*)td->io_ops_data;
    if (bsd->completed.size() == 0)
        return NULL;
    /* FIXME We ignore the event number and assume fio calls us exactly once for [0..nr_events-1] */
    struct io_u *ev = bsd->completed.back();
    bsd->completed.pop_back();
    return ev;
}

static int sec_io_u_init(struct thread_data *td, struct io_u *io)
{
    io->engine_data = NULL;
    return 0;
}

static void sec_io_u_free(struct thread_data *td, struct io_u *io)
{
}

static int sec_open_file(struct thread_data *td, struct fio_file *f)
{
    return 0;
}

static int sec_invalidate(struct thread_data *td, struct fio_file *f)
{
    return 0;
}

struct ioengine_ops ioengine = {
    .name               = "vitastor_secondary_osd",
    .version            = FIO_IOOPS_VERSION,
    .flags              = FIO_MEMALIGN | FIO_DISKLESSIO | FIO_NOEXTEND,
    .setup              = sec_setup,
    .init               = sec_init,
    .queue              = sec_queue,
    .getevents          = sec_getevents,
    .event              = sec_event,
    .cleanup            = sec_cleanup,
    .open_file          = sec_open_file,
    .invalidate         = sec_invalidate,
    .io_u_init          = sec_io_u_init,
    .io_u_free          = sec_io_u_free,
    .option_struct_size = sizeof(struct sec_options),
    .options            = options,
};

static void fio_init fio_sec_register(void)
{
    register_ioengine(&ioengine);
}

static void fio_exit fio_sec_unregister(void)
{
    unregister_ioengine(&ioengine);
}