t_hash_table.cpp

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/*****************************************************************************\
*                                                                             *
*  Name   : test_hash_table                                                   *
*  Author : Chris Koeritz                                                     *
*                                                                             *
*  Purpose:                                                                   *
*                                                                             *
*    Tests out the hash_table abstract data type.                             *
*                                                                             *
*******************************************************************************
* Copyright (c) 2001-$now By Author.  This program is free software; you can  *
* redistribute it and/or modify it under the terms of the GNU General Public  *
* License as published by the Free Software Foundation; either version 2 of   *
* the License or (at your option) any later version.  This is online at:      *
*     http://www.fsf.org/copyleft/gpl.html                                    *
* Please send any updates to: fred@gruntose.com                               *
\*****************************************************************************/

#include <basis/chaos.h>
#include <basis/guards.h>
#include <basis/istring.h>
#include <basis/set.cpp>
#include <data_struct/byte_hasher.h>
#include <data_struct/hash_table.cpp>
#include <mechanisms/time_stamp.h>
#include <opsystem/application_shell.h>
#include <loggers/console_logger.h>
#include <loggers/file_logger.h>
#include <data_struct/static_memory_gremlin.h>
#include <textual/string_manipulation.h>

const int TEST_DURATION = 4 * MINUTE_ms;
//const int TEST_DURATION = 20 * SECOND_ms;

const int MAX_DEFAULT_BITS = 2;
  // we start low since we will rehash occasionally.


enum test_actions {
  FIRST_TEST = 38,  // place-holder.
  ADD = FIRST_TEST,
    // adds an item that is probably new.
  ADD_ADD,
    // adds an item that is probably new, followed by another item under the
    // same key id.  this ensures the overwriting gets tested.
  ZAP,
    // finds an item we know is in the list and whacks it.
  ADD_ZAP,
    // adds a new item and immediately finds and zaps it.
  ZAP_ADD,
    // zaps an item that we know about and then adds a new item with the same
    // identifier.
  FIND,
    // locates an item in the list which we know should exist.
  ACQUIRE,
    // grabs an item out of the list (and tosses it).
  FIND_ZAP_ADD,
    // finds an item we know should exist, zaps it out of the list, then adds
    // a new item with the same id.
  ACQUIRE_ADD_ZAP,
    // removes an item from the list that we know should be there, adds it back
    // in, and then whacks it.
  FIND_ADD_FIND,
    // find an item with a particular id (one that we know should be in the
    // list) and then adds a different item using the same id.  the new item
    // is then sought.
  RESET,
    // tosses all data out of the hash table.  not done very often.
  CHECK_SANITY,
    // look for any problems or irregularities; print the contents of the list
    // if any are found.
  REHASH,
    // resizes the hash table.
  COPY,
    // copies a hash table to another hash table.
  LAST_TEST = COPY // place-holder; must equal test just prior.
};


// a simple object that is used as the contents of the hash_table.

class data_shuttle
{
public:
  int food_bar;
  istring snacky_string;
  bool hungry;
  byte_array chunk;
  chaos chao;

  data_shuttle()
  : snacky_string(string_manipulation::make_random_name()),
    chunk(chao.inclusive(100, 10000)) {}
};


class test_hash_table : public application_shell
{
public:
  test_hash_table();

  IMPLEMENT_CLASS_NAME("test_hash_table");

  int execute();
    // the main startup for the test.

  bool perform_a_test(test_actions test_type);
    // carries out the specifics of the "test_type".

  bool pick_a_test();
    // randomly picks one of the test types and performs it.

  static const char *test_name(test_actions test_type);

  // these functions each perform one type of test, which their names indicate.
  bool test_add();
  bool test_add_add();
  bool test_zap();
  bool test_add_zap();
  bool test_zap_add();
  bool test_find();
  bool test_acquire();
  bool test_find_zap_add();
  bool test_acquire_add_zap();
  bool test_find_add_find();
  bool test_reset();
  bool test_check_sanity();
  bool test_copy();
  bool test_rehash();

  static bool equivalence_applier(const int &key, data_shuttle &item,
          void *dlink);

private:
  int_set _keys_in_use;  // keys that we think are stored in the table.
  hash_table<int, data_shuttle> _the_table;  // our table under test.
  int _hits[LAST_TEST - FIRST_TEST + 1];  // tracks our testing activities.
  int _tested;  // simple counter of number of test calls.
};


typedef hash_table<int, data_shuttle> our_hash;  // cleans up somewhat.


test_hash_table::test_hash_table()
: application_shell("t_hash_table"),
  _the_table(rotating_byte_hasher(), MAX_DEFAULT_BITS),
  _tested(0)
{
  for (int i = FIRST_TEST; i <= LAST_TEST; i++)
    _hits[i - FIRST_TEST] = 0;
}

int test_hash_table::execute()
{
  time_stamp exit_time(TEST_DURATION);
  while (time_stamp() < exit_time) pick_a_test();
  log(isprintf("did %d tests.\n", _tested));
  log("Test Activity:");
  for (int i = 0; i < LAST_TEST - FIRST_TEST + 1; i++)
    log(istring(istring::SPRINTF, "%d (%s): %d hits", i + FIRST_TEST,
        test_name(test_actions(i + FIRST_TEST)), _hits[i]));
  log(isprintf("note that test %d will seldom be executed.", RESET));
  guards::alert_message("hash_table:: works for those functions tested.");
  return 0;
}

const char *test_hash_table::test_name(test_actions test_type)
{
  switch (test_type) {
    case ADD: return "ADD";
    case ADD_ADD: return "ADD_ADD";
    case ZAP: return "ZAP";
    case ADD_ZAP: return "ADD_ZAP";
    case ZAP_ADD: return "ZAP_ADD";
    case FIND: return "FIND";
    case ACQUIRE: return "ACQUIRE";
    case FIND_ZAP_ADD: return "FIND_ZAP_ADD";
    case ACQUIRE_ADD_ZAP: return "ACQUIRE_ADD_ZAP";
    case FIND_ADD_FIND: return "FIND_ADD_FIND";
    case RESET: return "RESET";
    case COPY: return "COPY";
    case REHASH: return "REHASH";
    case CHECK_SANITY: return "CHECK_SANITY";
    default: return "UnknownTest";
  }
}

bool test_hash_table::perform_a_test(test_actions test_type)
{
  FUNCDEF("perform_a_test");

//  log(istring(test_name(test_type)) + " ");

  switch (test_type) {
    case ADD: return test_add();
    case ADD_ADD: return test_add_add();
    case ZAP: return test_zap();
    case ADD_ZAP: return test_add_zap();
    case ZAP_ADD: return test_zap_add();
    case FIND: return test_find();
    case ACQUIRE: return test_acquire();
    case FIND_ZAP_ADD: return test_find_zap_add();
    case ACQUIRE_ADD_ZAP: return test_acquire_add_zap();
    case FIND_ADD_FIND: return test_find_add_find();
    case RESET: return test_reset();
    case COPY: return test_copy();
    case REHASH: return test_rehash();
    case CHECK_SANITY: return test_check_sanity();
    default:
      deadly_error(class_name(), func, "missing case has been seen!");
      return false;  // never gets here.
  }
}

bool test_hash_table::pick_a_test()
{
  _tested++;
  return perform_a_test(test_actions(randomizer().inclusive(FIRST_TEST,
      LAST_TEST)));
}

bool test_hash_table::test_add()
{
  FUNCDEF("test_add");
  _hits[ADD - FIRST_TEST]++;
  int random_id = randomizer().inclusive(-MAXINT / 4, MAXINT / 4);
  data_shuttle *to_add = new data_shuttle;
  to_add->snacky_string = string_manipulation::make_random_name();
  to_add->food_bar = random_id;
  _the_table.add(random_id, to_add);
  if (_keys_in_use.member(random_id))
    return true;  // already was there so we replaced.
  _keys_in_use.add(random_id);
  return true;
}


hash_table<int, data_shuttle> *_hang_on = NIL;
  // must be set before calling the apply method.

bool test_hash_table::equivalence_applier(const int &key, data_shuttle &item,
    void *formal(dlink))
{
  FUNCDEF("equivalence_applier");
  data_shuttle *found = _hang_on->find(key);
  if (!found)
    deadly_error(test_hash_table::static_class_name(), func, "no equivalent entry was found in second list");

  if (item.food_bar != found->food_bar)
    deadly_error(test_hash_table::static_class_name(), func, "food_bar differs");
  if (item.snacky_string != found->snacky_string)
    deadly_error(test_hash_table::static_class_name(), func, "snacky_string differs");
  if (item.hungry != found->hungry)
    deadly_error(test_hash_table::static_class_name(), func, "hungry differs");
  return true;
}

bool test_hash_table::test_rehash()
{
  FUNCDEF("test_rehash");
  // we don't want to rehash too often; it is expensive.
  int maybe = randomizer().inclusive(1, 50);
  if (maybe < 32) return true;  // not this time.

  _hits[REHASH - FIRST_TEST]++;

  hash_table<int, data_shuttle> table_copy(rotating_byte_hasher(), _the_table.max_bits());

//log("copying table...");
  copy_hash_table(table_copy, _the_table);
    // make a copy of the table.
  
//log("rehashing table...");
  _the_table.rehash(randomizer().inclusive(1, 20));
//hmmm: need test of non-existent dehash function that reduces max_bits.

//log("comparing table...");
  _hang_on = &_the_table;
  table_copy.apply(equivalence_applier, NIL);
//log("done copy and compare.");

  return true;
}

bool test_hash_table::test_copy()
{
  FUNCDEF("test_copy");
  // we don't want to copy too often.  it's a heavy operation.
  int maybe = randomizer().inclusive(1, 50);
  if (maybe > 16) return true;  // not this time.

  _hits[COPY - FIRST_TEST]++;

  hash_table<int, data_shuttle> table_copy(rotating_byte_hasher(), MAX_DEFAULT_BITS);

//log("copying table...");
  copy_hash_table(table_copy, _the_table);
    // make a copy of the table.
  
//log("comparing table...");
  _hang_on = &_the_table;
  table_copy.apply(equivalence_applier, NIL);
//log("done copy and compare.");

  return true;
}


bool test_hash_table::test_add_add()
{
  FUNCDEF("test_add_add");
  _hits[ADD_ADD - FIRST_TEST]++;
  int random_id = randomizer().inclusive(-MAXINT / 4, MAXINT / 4);
  data_shuttle *to_add = new data_shuttle;
  to_add->snacky_string = string_manipulation::make_random_name();
  to_add->food_bar = random_id;
  _the_table.add(random_id, to_add);
  // add the new key if it's really new.
  if (!_keys_in_use.member(random_id)) _keys_in_use.add(random_id);

  // second add on same id.
  data_shuttle *next_add = new data_shuttle;
  next_add->snacky_string = string_manipulation::make_random_name();
  next_add->food_bar = random_id;
  if (_the_table.add(random_id, next_add) != our_hash::EXISTING)
    deadly_error(class_name(), func, "second add said first failed!");

  return true;
}

bool test_hash_table::test_zap()
{
  FUNCDEF("test_zap");
  int maybe = randomizer().inclusive(1, 1000);
  if (maybe > 50) return true;
  if (!_keys_in_use.elements()) return false;  // can't do it yet.
  _hits[ZAP - FIRST_TEST]++;
  int rand_indy = randomizer().inclusive(0, _keys_in_use.elements() - 1);
  int dead_key = _keys_in_use[rand_indy];
  _keys_in_use.remove(dead_key);  // remove the record of that key.
  if (!_the_table.zap(dead_key))
    deadly_error(class_name(), func, "key should have been present but wasn't");
  return true;
}

bool test_hash_table::test_add_zap()
{
  FUNCDEF("test_add_zap");
  // add.
  _hits[ADD_ZAP - FIRST_TEST]++;
  int random_id = randomizer().inclusive(-MAXINT / 4, MAXINT / 4);
  data_shuttle *to_add = new data_shuttle;
  to_add->snacky_string = string_manipulation::make_random_name();
  to_add->food_bar = random_id;
  _the_table.add(random_id, to_add);
  // zap.
  if (!_the_table.zap(random_id))
    deadly_error(class_name(), func, "key should have been present but wasn't");
  return true;
}

bool test_hash_table::test_zap_add()
{
  FUNCDEF("test_zap_add");
  if (!_keys_in_use.elements()) return false;  // can't do it yet.
  _hits[ZAP_ADD - FIRST_TEST]++;
  int rand_indy = randomizer().inclusive(0, _keys_in_use.elements() - 1);
  // in the end, the key list state won't be changed unless the test fails.
  int dead_key = _keys_in_use[rand_indy];
  if (!_the_table.zap(dead_key))
    deadly_error(class_name(), func, "key should have been there but was not!");

  data_shuttle *to_add = new data_shuttle;
  to_add->snacky_string = string_manipulation::make_random_name();
  to_add->food_bar = dead_key;
  outcome ret = _the_table.add(dead_key, to_add);
  if (ret != our_hash::IS_NEW)
    deadly_error(class_name(), func, "key was already present somehow!");
  return true;
}

bool test_hash_table::test_find()
{
  FUNCDEF("test_find");
  if (!_keys_in_use.elements()) return false;  // can't do it yet.
  _hits[FIND - FIRST_TEST]++;
  int rand_indy = randomizer().inclusive(0, _keys_in_use.elements() - 1);
  int find_key = _keys_in_use[rand_indy];
  data_shuttle *found = NIL;
  if (!_the_table.find(find_key, found))
    deadly_error(class_name(), func, "key should have been there but was not!");
  if (!found)
    deadly_error(class_name(), func, "key was found but contents were NIL!");
  if (found->food_bar != find_key)
    deadly_error(class_name(), func, "stored key differed from real key!");
  if (!found->snacky_string.length())
    deadly_error(class_name(), func, "stored string had zero length!");
  return true;
}

bool test_hash_table::test_acquire()
{
  FUNCDEF("test_acquire");
  int maybe = randomizer().inclusive(1, 1000);
  if (maybe > 150) return true;
  if (!_keys_in_use.elements()) return false;  // can't do it yet.
  _hits[ACQUIRE - FIRST_TEST]++;
  int rand_indy = randomizer().inclusive(0, _keys_in_use.elements() - 1);
  int find_key = _keys_in_use[rand_indy];
  _keys_in_use.remove(find_key);  // remove the record of that key.
  data_shuttle *found = _the_table.acquire(find_key);
  if (!found)
    deadly_error(class_name(), func, "key should have been there but was not!");
  if (found->food_bar != find_key)
    deadly_error(class_name(), func, "stored key differed from real key!");
  if (!found->snacky_string.length())
    deadly_error(class_name(), func, "stored string had zero length!");
  WHACK(found);
  found = _the_table.acquire(find_key);
  if (found)
    deadly_error(class_name(), func, "key was supposedly there after zap!");
  return true;
}

bool test_hash_table::test_find_zap_add()
{
  FUNCDEF("test_find_zap_add");
  // find.
  if (!_keys_in_use.elements()) return false;  // can't do it yet.
  _hits[FIND_ZAP_ADD - FIRST_TEST]++;
  int rand_indy = randomizer().inclusive(0, _keys_in_use.elements() - 1);
  // this is another key list invariant function, if it works.
  int find_key = _keys_in_use[rand_indy];
  data_shuttle *found = NIL;
  if (!_the_table.find(find_key, found))
    deadly_error(class_name(), func, "key should have been there but was not!");
  if (!found)
    deadly_error(class_name(), func, "key was found but contents were NIL!");
  if (found->food_bar != find_key)
    deadly_error(class_name(), func, "stored key differed from real key!");
  if (!found->snacky_string.length())
    deadly_error(class_name(), func, "stored string had zero length!");
  // zap.
  if (!_the_table.zap(find_key))
    deadly_error(class_name(), func, "could not zap the item we had found!");
  // add.
  data_shuttle *to_add = new data_shuttle;
  to_add->snacky_string = string_manipulation::make_random_name();
  to_add->food_bar = find_key;
  if (_the_table.add(find_key, to_add) != our_hash::IS_NEW)
    deadly_error(class_name(), func, "the item we zapped was still there!");
  return true;
}

bool test_hash_table::test_reset()
{
  FUNCDEF("test_reset");
  int maybe = randomizer().inclusive(1, 1000);
  // this is hardly ever hit, but it loses all contents too often otherwise.
  if ( (maybe > 372) || (maybe < 368) ) return true;

  // we hit the big time; we will reset now.
  _hits[RESET - FIRST_TEST]++;
  _the_table.reset();
  for (int i = _keys_in_use.elements() - 1; i >= 0; i--) {
    int dead_key = _keys_in_use[i];
    if (_the_table.acquire(dead_key))
      deadly_error(class_name(), func, "after reset, we found an item!");
    _keys_in_use.remove(dead_key);
  }
  return true;
}

//hmmm: implement these tests!

bool test_hash_table::test_acquire_add_zap()
{
  _hits[ACQUIRE_ADD_ZAP - FIRST_TEST]++;
return false;
}

bool test_hash_table::test_find_add_find()
{
  _hits[FIND_ADD_FIND - FIRST_TEST]++;
return false;
}

bool test_hash_table::test_check_sanity()
{
  _hits[CHECK_SANITY - FIRST_TEST]++;
return false;
}


HOOPLE_MAIN(test_hash_table, )

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