/** @file

  A brief file description

  @section license License

  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.
 */

#include "P_AIO.h"
#include "InkAPIInternal.h"
#include "tscore/I_Layout.h"
#include "tscore/TSSystemState.h"
#include <iostream>
#include <fstream>

using std::cout;
using std::endl;

// Necessary for AIO
#if defined(solaris)
int net_config_poll_timeout = 30;
#else
int net_config_poll_timeout = 10;
#endif

#include "diags.i"

#define MAX_DISK_THREADS 200
#ifdef DISK_ALIGN
#define MIN_OFFSET (32 * 1024)
#else
#define MIN_OFFSET (8 * 1024)
#endif
enum {
  READ_MODE,
  WRITE_MODE,
  RANDOM_READ_MODE,
};

struct AIO_Device;
int n_accessors = 0;
int orig_n_accessors;
AIO_Device *dev[MAX_DISK_THREADS];

extern RecInt cache_config_threads_per_disk;

int write_after         = 0;
int write_skip          = 0;
int hotset_size         = 20;
double hotset_frequency = 0.9;
int touch_data          = 0;
int disk_size           = 4000;
int read_size           = 1024;
char *disk_path[MAX_DISK_THREADS];
int n_disk_path      = 0;
int run_time         = 0;
int threads_per_disk = 1;
int delete_disks     = 0;
int max_size         = 0;
int use_lseek        = 0;

int chains                    = 1;
double seq_read_percent       = 0.0;
double seq_write_percent      = 0.0;
double rand_read_percent      = 0.0;
double real_seq_read_percent  = 0.0;
double real_seq_write_percent = 0.0;
double real_rand_read_percent = 0.0;
int seq_read_size             = 0;
int seq_write_size            = 0;
int rand_read_size            = 0;

struct AIO_Device : public Continuation {
  char *path;
  int fd;
  int id;
  char *buf;
  ink_hrtime time_start, time_end;
  int seq_reads;
  int seq_writes;
  int rand_reads;
  int hotset_idx;
  int mode;
  AIOCallback *io;
  AIO_Device(ProxyMutex *m) : Continuation(m)
  {
    hotset_idx = 0;
    io         = new_AIOCallback();
    time_start = 0;
    SET_HANDLER(&AIO_Device::do_hotset);
  }
  int
  select_mode(double p)
  {
    if (p < real_seq_read_percent) {
      return READ_MODE;
    } else if (p < real_seq_read_percent + real_seq_write_percent) {
      return WRITE_MODE;
    } else {
      return RANDOM_READ_MODE;
    }
  };
  void
  do_touch_data(off_t orig_len, off_t orig_offset)
  {
    if (!touch_data) {
      return;
    }
    unsigned int len    = static_cast<unsigned int>(orig_len);
    unsigned int offset = static_cast<unsigned int>(orig_offset);
    offset              = offset % 1024;
    char *b             = buf;
    unsigned *x         = reinterpret_cast<unsigned *>(b);
    for (unsigned j = 0; j < (len / sizeof(int)); j++) {
      x[j]   = offset;
      offset = (offset + 1) % 1024;
    }
  };
  int
  do_check_data(off_t orig_len, off_t orig_offset)
  {
    if (!touch_data) {
      return 0;
    }
    unsigned int len    = static_cast<unsigned int>(orig_len);
    unsigned int offset = static_cast<unsigned int>(orig_offset);
    offset              = offset % 1024;
    unsigned *x         = reinterpret_cast<unsigned *>(buf);
    for (unsigned j = 0; j < (len / sizeof(int)); j++) {
      if (x[j] != offset) {
        return 1;
      }
      offset = (offset + 1) % 1024;
    }
    return 0;
  }
  int do_hotset(int event, Event *e);
  int do_fd(int event, Event *e);
};

void
dump_summary()
{
  /* dump timing info */
  printf("Writing summary info\n");

  printf("----------\n");
  printf("parameters\n");
  printf("----------\n");
  printf("%d disks\n", n_disk_path);
  printf("%d chains\n", chains);
  printf("%d threads_per_disk\n", threads_per_disk);

  printf("%0.1f percent %d byte seq_reads by volume\n", seq_read_percent * 100.0, seq_read_size);
  printf("%0.1f percent %d byte seq_writes by volume\n", seq_write_percent * 100.0, seq_write_size);
  printf("%0.1f percent %d byte rand_reads by volume\n", rand_read_percent * 100.0, rand_read_size);
  printf("-------\n");
  printf("factors\n");
  printf("-------\n");
  printf("%0.1f percent %d byte seq_reads by count\n", real_seq_read_percent * 100.0, seq_read_size);
  printf("%0.1f percent %d byte seq_writes by count\n", real_seq_write_percent * 100.0, seq_write_size);
  printf("%0.1f percent %d byte rand_reads by count\n", real_rand_read_percent * 100.0, rand_read_size);

  printf("-------------------------\n");
  printf("individual thread results\n");
  printf("-------------------------\n");
  double total_seq_reads  = 0;
  double total_seq_writes = 0;
  double total_rand_reads = 0;
  double total_secs       = 0.0;
  for (int i = 0; i < orig_n_accessors; i++) {
    double secs    = (dev[i]->time_end - dev[i]->time_start) / 1000000000.0;
    double ops_sec = (dev[i]->seq_reads + dev[i]->seq_writes + dev[i]->rand_reads) / secs;
    printf("%s: #sr:%d #sw:%d #rr:%d %0.1f secs %0.1f ops/sec\n", dev[i]->path, dev[i]->seq_reads, dev[i]->seq_writes,
           dev[i]->rand_reads, secs, ops_sec);
    total_secs += secs;
    total_seq_reads += dev[i]->seq_reads;
    total_seq_writes += dev[i]->seq_writes;
    total_rand_reads += dev[i]->rand_reads;
  }
  printf("-----------------\n");
  printf("aggregate results\n");
  printf("-----------------\n");
  total_secs /= orig_n_accessors;
  float sr = (total_seq_reads * seq_read_size) / total_secs;
  sr /= 1024.0 * 1024.0;
  float sw = (total_seq_writes * seq_write_size) / total_secs;
  sw /= 1024.0 * 1024.0;
  float rr = (total_rand_reads * rand_read_size) / total_secs;
  rr /= 1024.0 * 1024.0;
  printf("%f ops %0.2f mbytes/sec %0.1f ops/sec %0.1f ops/sec/disk seq_read\n", total_seq_reads, sr, total_seq_reads / total_secs,
         total_seq_reads / total_secs / n_disk_path);
  printf("%f ops %0.2f mbytes/sec %0.1f ops/sec %0.1f ops/sec/disk seq_write\n", total_seq_writes, sw,
         total_seq_writes / total_secs, total_seq_writes / total_secs / n_disk_path);
  printf("%f ops %0.2f mbytes/sec %0.1f ops/sec %0.1f ops/sec/disk rand_read\n", total_rand_reads, rr,
         total_rand_reads / total_secs, total_rand_reads / total_secs / n_disk_path);
  printf("%0.2f total mbytes/sec\n", sr + sw + rr);
  printf("----------------------------------------------------------\n");

  if (delete_disks) {
    for (int i = 0; i < n_disk_path; i++) {
      unlink(disk_path[i]);
    }
  }
  exit(0);
}

int
AIO_Device::do_hotset(int /* event ATS_UNUSED */, Event * /* e ATS_UNUSED */)
{
  off_t max_offset         = (static_cast<off_t>(disk_size)) * 1024 * 1024;
  io->aiocb.aio_lio_opcode = LIO_WRITE;
  io->aiocb.aio_fildes     = fd;
  io->aiocb.aio_offset     = MIN_OFFSET + hotset_idx * max_size;
  do_touch_data(seq_read_size, io->aiocb.aio_offset);
  ink_assert(!do_check_data(seq_read_size, io->aiocb.aio_offset));
  if (!hotset_idx) {
    fprintf(stderr, "Starting hotset document writing \n");
  }
  if (io->aiocb.aio_offset > max_offset) {
    fprintf(stderr, "Finished hotset documents  [%d] offset [%6.0f] size [%6.0f]\n", hotset_idx, static_cast<float> MIN_OFFSET,
            static_cast<float>(max_size));
    SET_HANDLER(&AIO_Device::do_fd);
    eventProcessor.schedule_imm(this);
    return (0);
  }
  io->aiocb.aio_nbytes = seq_read_size;
  io->aiocb.aio_buf    = buf;
  io->action           = this;
  io->thread           = mutex->thread_holding;
  ink_assert(ink_aio_write(io) >= 0);
  hotset_idx++;
  return 0;
}

int
AIO_Device::do_fd(int /* event ATS_UNUSED */, Event * /* e ATS_UNUSED */)
{
  if (!time_start) {
    time_start = Thread::get_hrtime();
    fprintf(stderr, "Starting the aio_testing \n");
  }
  if ((Thread::get_hrtime() - time_start) > (run_time * HRTIME_SECOND)) {
    time_end = Thread::get_hrtime();
    ink_atomic_increment(&n_accessors, -1);
    if (n_accessors <= 0) {
      dump_summary();
    }
    return 0;
  }

  off_t max_offset        = (static_cast<off_t>(disk_size)) * 1024 * 1024;   // MB-GB
  off_t max_hotset_offset = (static_cast<off_t>(hotset_size)) * 1024 * 1024; // MB-GB
  off_t seq_read_point    = (static_cast<off_t> MIN_OFFSET);
  off_t seq_write_point   = (static_cast<off_t> MIN_OFFSET) + max_offset / 2 + write_after * 1024 * 1024;
  seq_write_point += (id % n_disk_path) * (max_offset / (threads_per_disk * 4));
  if (seq_write_point > max_offset) {
    seq_write_point = MIN_OFFSET;
  }

  if (io->aiocb.aio_lio_opcode == LIO_READ) {
    ink_assert(!do_check_data(io->aiocb.aio_nbytes, io->aiocb.aio_offset));
  }
  memset((void *)buf, 0, max_size);
  io->aiocb.aio_fildes = fd;
  io->aiocb.aio_buf    = buf;
  io->action           = this;
  io->thread           = mutex->thread_holding;

  switch (select_mode(drand48())) {
  case READ_MODE:
    io->aiocb.aio_offset     = seq_read_point;
    io->aiocb.aio_nbytes     = seq_read_size;
    io->aiocb.aio_lio_opcode = LIO_READ;
    ink_assert(ink_aio_read(io) >= 0);
    seq_read_point += seq_read_size;
    if (seq_read_point > max_offset) {
      seq_read_point = MIN_OFFSET;
    }
    seq_reads++;
    break;
  case WRITE_MODE:
    io->aiocb.aio_offset     = seq_write_point;
    io->aiocb.aio_nbytes     = seq_write_size;
    io->aiocb.aio_lio_opcode = LIO_WRITE;
    do_touch_data(seq_write_size, (static_cast<int>(seq_write_point)) % 1024);
    ink_assert(ink_aio_write(io) >= 0);
    seq_write_point += seq_write_size;
    seq_write_point += write_skip;
    if (seq_write_point > max_offset) {
      seq_write_point = MIN_OFFSET;
    }

    seq_writes++;
    break;
  case RANDOM_READ_MODE: {
    // fprintf(stderr, "random read started \n");
    double p, f;
    p       = drand48();
    f       = drand48();
    off_t o = 0;
    if (f < hotset_frequency) {
      o = static_cast<off_t>(p) * max_hotset_offset;
    } else {
      o = static_cast<off_t>(p) * (max_offset - rand_read_size);
    }
    if (o < MIN_OFFSET) {
      o = MIN_OFFSET;
    }
    o                        = (o + (seq_read_size - 1)) & (~(seq_read_size - 1));
    io->aiocb.aio_offset     = o;
    io->aiocb.aio_nbytes     = rand_read_size;
    io->aiocb.aio_lio_opcode = LIO_READ;
    ink_assert(ink_aio_read(io) >= 0);
    rand_reads++;
    break;
  }
  }
  return 0;
}

#define PARAM(_s)                               \
  else if (strcmp(field_name, #_s) == 0)        \
  {                                             \
    fin >> _s;                                  \
    cout << "reading " #_s " = " << _s << endl; \
  }

int
read_config(const char *config_filename)
{
  std::ifstream fin(config_filename);
  char field_name[256];
  char field_value[256];

  if (!fin.rdbuf()->is_open()) {
    fin.open("sample.cfg");
    if (!fin.rdbuf()->is_open()) {
      cout << "cannot open config files " << config_filename << endl;
      return (0);
    }
  }
  while (!fin.eof()) {
    field_name[0] = '\0';
    fin >> field_name;
    if (0) {
    }
    PARAM(hotset_size)
    PARAM(hotset_frequency)
    PARAM(touch_data)
    PARAM(use_lseek)
    PARAM(write_after)
    PARAM(write_skip)
    PARAM(disk_size)
    PARAM(seq_read_percent)
    PARAM(seq_write_percent)
    PARAM(rand_read_percent)
    PARAM(seq_read_size)
    PARAM(seq_write_size)
    PARAM(rand_read_size)
    PARAM(run_time)
    PARAM(chains)
    PARAM(threads_per_disk)
    PARAM(delete_disks)
    else if (strcmp(field_name, "disk_path") == 0)
    {
      assert(n_disk_path < MAX_DISK_THREADS);
      fin >> field_value;
      disk_path[n_disk_path] = strdup(field_value);
      cout << "reading disk_path = " << disk_path[n_disk_path] << endl;
      n_disk_path++;
    }
  }
  assert(read_size > 0);
  int t                  = seq_read_size + seq_write_size + rand_read_size;
  real_seq_read_percent  = seq_read_percent;
  real_seq_write_percent = seq_write_percent;
  real_rand_read_percent = rand_read_percent;
  if (seq_read_size) {
    real_seq_read_percent *= t / seq_read_size;
  }
  if (seq_write_size) {
    real_seq_write_percent *= t / seq_write_size;
  }
  if (rand_read_size) {
    real_rand_read_percent *= t / rand_read_size;
  }
  float tt               = real_seq_read_percent + real_seq_write_percent + real_rand_read_percent;
  real_seq_read_percent  = real_seq_read_percent / tt;
  real_seq_write_percent = real_seq_write_percent / tt;
  real_rand_read_percent = real_rand_read_percent / tt;
  return (1);
}

int
main(int /* argc ATS_UNUSED */, char *argv[])
{
  int i;

  Layout::create();
  init_diags("", nullptr);
  RecProcessInit(RECM_STAND_ALONE);
  ink_event_system_init(EVENT_SYSTEM_MODULE_PUBLIC_VERSION);
  eventProcessor.start(ink_number_of_processors());

  Thread *main_thread = new EThread;
  main_thread->set_specific();

#if AIO_MODE == AIO_MODE_NATIVE
  int etype            = ET_NET;
  int n_netthreads     = eventProcessor.n_threads_for_type[etype];
  EThread **netthreads = eventProcessor.eventthread[etype];
  for (int i = 0; i < n_netthreads; ++i) {
    netthreads[i]->diskHandler = new DiskHandler();
    netthreads[i]->schedule_imm(netthreads[i]->diskHandler);
  }
#endif

  RecProcessStart();
  ink_aio_init(AIO_MODULE_PUBLIC_VERSION);
  srand48(time(nullptr));
  printf("input file %s\n", argv[1]);
  if (!read_config(argv[1])) {
    exit(1);
  }

  max_size = seq_read_size;
  if (seq_write_size > max_size) {
    max_size = seq_write_size;
  }
  if (rand_read_size > max_size) {
    max_size = rand_read_size;
  }

  cache_config_threads_per_disk = threads_per_disk;
  orig_n_accessors              = n_disk_path * threads_per_disk;

  for (i = 0; i < n_disk_path; i++) {
    for (int j = 0; j < threads_per_disk; j++) {
      dev[n_accessors]             = new AIO_Device(new_ProxyMutex());
      dev[n_accessors]->id         = i * threads_per_disk + j;
      dev[n_accessors]->path       = disk_path[i];
      dev[n_accessors]->seq_reads  = 0;
      dev[n_accessors]->seq_writes = 0;
      dev[n_accessors]->rand_reads = 0;
      dev[n_accessors]->fd         = open(dev[n_accessors]->path, O_RDWR | O_CREAT, 0600);
      fchmod(dev[n_accessors]->fd, S_IRWXU | S_IRWXG);
      if (dev[n_accessors]->fd < 0) {
        perror(disk_path[i]);
        exit(1);
      }
      dev[n_accessors]->buf = static_cast<char *>(valloc(max_size));
      eventProcessor.schedule_imm(dev[n_accessors]);
      n_accessors++;
    }
  }

  while (!TSSystemState::is_event_system_shut_down()) {
    sleep(1);
  }
  delete main_thread;
}