/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * 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.
 */
#include <vppinfra/time.h>
#include <vppinfra/cache.h>
#include <vppinfra/error.h>

#include <vppinfra/bihash_8_8.h>
#include <vppinfra/bihash_template.h>

#include <vppinfra/bihash_template.c>

typedef struct {
  u32 seed;
  u32 nbuckets;
  u32 nitems;
  u32 search_iter;
  int careful_delete_tests;
  int verbose;
  int non_random_keys;
  uword * key_hash;
  u64 * keys;
  BVT(clib_bihash) hash;
  clib_time_t clib_time;

  unformat_input_t * input;
  
} test_main_t;

test_main_t test_main;

uword vl (void * v)
{
    return vec_len (v);
}

static clib_error_t * test_bihash (test_main_t * tm)
{
  int i, j;
  uword * p;
  uword total_searches;
  f64 before, delta;
  BVT(clib_bihash) * h;
  BVT(clib_bihash_kv) kv;

  h = &tm->hash;

  BV(clib_bihash_init) (h, "test", tm->nbuckets, 3ULL<<30);
  
  fformat (stdout, "Pick %lld unique %s keys...\n", 
           tm->nitems, tm->non_random_keys ? "non-random" : "random");

  for (i = 0; i < tm->nitems; i++)
    {
      u64 rndkey;

      if (tm->non_random_keys == 0)
        {

        again:
          rndkey = random_u64 (&tm->seed);
          
          p = hash_get (tm->key_hash, rndkey);
          if (p)
            goto again;
        }
      else
          rndkey = (u64)(i+1) << 16;

      hash_set (tm->key_hash, rndkey, i+1);
      vec_add1 (tm->keys, rndkey);
    }

  fformat (stdout, "Add items...\n");
  for (i = 0; i < tm->nitems; i++)
    {
      kv.key = tm->keys[i];
      kv.value = i+1;

      BV(clib_bihash_add_del) (h, &kv, 1 /* is_add */);

      if (tm->verbose > 1)
        {
          fformat (stdout, "--------------------\n");
          fformat (stdout, "After adding key %llu value %lld...\n", 
                   tm->keys[i], (u64)(i+1));
          fformat (stdout, "%U", BV(format_bihash), h, 2 /* very verbose */);
        }
    }

  fformat (stdout, "%U", BV(format_bihash), h, 0 /* very verbose */);

  fformat (stdout, "Search for items %d times...\n", tm->search_iter);

  before = clib_time_now (&tm->clib_time);

  for (j = 0; j < tm->search_iter; j++)
    {
      u64 hash1 = clib_xxhash (tm->keys[0]);

      for (i = 0; i < tm->nitems; i++)
        {
          if (i < (tm->nitems - 3))
            {
              clib_bihash_bucket_t * b;
              BVT(clib_bihash_value) * v;
              u64 hash2 = clib_xxhash (tm->keys[i+3]);
              u32 bucket_index = hash2 & (h->nbuckets-1);
              b = &h->buckets[bucket_index];
              CLIB_PREFETCH (b, CLIB_CACHE_LINE_BYTES, LOAD);

              bucket_index = hash1 & (h->nbuckets-1);
              b = &h->buckets[bucket_index];
              v = BV(clib_bihash_get_value) (h, b->offset);
              hash1 >>= h->log2_nbuckets;
              hash1 = hash1 & ((1<<b->log2_pages)-1);
              v += hash1;
              CLIB_PREFETCH (v, CLIB_CACHE_LINE_BYTES, LOAD);
              
              hash1 = hash2;
            }

          kv.key = tm->keys[i];
          if (BV(clib_bihash_search) (h, &kv, &kv) < 0)
            clib_warning ("search for key %lld failed unexpectedly\n", 
                          tm->keys[i]);
          if (kv.value != (u64)(i+1))
            clib_warning ("search for key %lld returned %lld, not %lld\n",
                          tm->keys, kv.value, (u64)(i+1));
        }
    }

  delta = clib_time_now (&tm->clib_time) - before;
  total_searches = (uword)tm->search_iter * (uword) tm->nitems;

  if (delta > 0)
    fformat (stdout, "%.f searches per second\n",
             ((f64)total_searches) / delta);

  fformat (stdout, "%lld searches in %.6f seconds\n", total_searches, delta);

  fformat (stdout, "Standard E-hash search for items %d times...\n", 
           tm->search_iter);

  before = clib_time_now (&tm->clib_time);

  for (j = 0; j < tm->search_iter; j++)
    {
      for (i = 0; i < tm->nitems; i++)
        {
          p = hash_get (tm->key_hash, tm->keys[i]);
          if (p == 0 || p[0] != (uword)(i+1))
            clib_warning ("ugh, couldn't find %lld\n", tm->keys[i]);
        }
    }

  delta = clib_time_now (&tm->clib_time) - before;
  total_searches = (uword)tm->search_iter * (uword) tm->nitems;

  fformat (stdout, "%lld searches in %.6f seconds\n", total_searches, delta);

  if (delta > 0)
    fformat (stdout, "%.f searches per second\n",
             ((f64)total_searches) / delta);

  fformat (stdout, "Delete items...\n");

  for (i = 0; i < tm->nitems; i++)
    {
      int j;
      int rv;

      kv.key = tm->keys[i];
      kv.value = (u64)(i+1);
      rv = BV(clib_bihash_add_del) (h, &kv,  0 /* is_add */);

      if (rv < 0)
        clib_warning ("delete key %lld not ok but should be",
                      tm->keys[i]);

      if (tm->careful_delete_tests)
        {
          for (j = 0; j < tm->nitems; j++)
            {
              kv.key = tm->keys[j];
              rv = BV(clib_bihash_search) (h, &kv, &kv);
              if (j <= i && rv >= 0)
                {
                  clib_warning 
                    ( "i %d j %d search ok but should not be, value %lld",
                      i, j, kv.value);
                }
              if (j > i && rv < 0)
                {
                  clib_warning ("i %d j %d search not ok but should be",
                                i, j);
                }
            }
        }
    }

  fformat (stdout, "After deletions, should be empty...\n");

  fformat (stdout, "%U", BV(format_bihash), h, 0 /* very verbose */);
  return 0;
}

clib_error_t * 
test_bihash_main (test_main_t * tm)
{
  unformat_input_t * i = tm->input;
  clib_error_t * error;

  while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (i, "seed %u", &tm->seed))
        ;

      else if (unformat (i, "nbuckets %d", &tm->nbuckets))
        ;
      else if (unformat (i, "non-random-keys"))
        tm->non_random_keys = 1;
      else if (unformat (i, "nitems %d", &tm->nitems))
        ;
      else if (unformat (i, "careful %d", &tm->careful_delete_tests))
        ;
      else if (unformat (i, "verbose %d", &tm->verbose))
        ;
      else if (unformat (i, "search %d", &tm->search_iter))
        ;
      else if (unformat (i, "verbose"))
        tm->verbose = 1;
      else
        return clib_error_return (0, "unknown input '%U'", 
                                  format_unformat_error, i);
    }
    
  error = test_bihash (tm);

  return error;
}

#ifdef CLIB_UNIX
int main (int argc, char * argv[])
{
  unformat_input_t i;
  clib_error_t * error;
  test_main_t * tm = &test_main;

  clib_mem_init (0, 3ULL<<30);

  tm->input = &i;
  tm->seed = 0xdeaddabe;

  tm->nbuckets = 2;
  tm->nitems = 5;
  tm->verbose = 1;
  tm->search_iter = 1;
  tm->careful_delete_tests = 0;
  tm->key_hash = hash_create (0, sizeof (uword));
  clib_time_init (&tm->clib_time);

  unformat_init_command_line (&i, argv);
  error = test_bihash_main (tm);
  unformat_free (&i);

  if (error)
    {
      clib_error_report (error);
      return 1;
    }
  return 0;
}
#endif /* CLIB_UNIX */