/* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- */
// vim: ft=cpp:expandtab:ts=8:sw=4:softtabstop=4:
#ident "$Id$"
/*======
This file is part of TokuDB


Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved.

    TokuDBis is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2,
    as published by the Free Software Foundation.

    TokuDB is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with TokuDB.  If not, see <http://www.gnu.org/licenses/>.

======= */

#ident "Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved."

// Test cardinality algorithm on a 2 level key where the first level is random in a space of size maxrand
// and the second level is unique.

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <memory.h>
#include <assert.h>
#include <errno.h>
#include <db.h>
#if __linux__
#include <endian.h>
#endif
#include <sys/stat.h>
typedef unsigned long long ulonglong;
#include "tokudb_status.h"
#include "tokudb_buffer.h"
#include "fake_mysql.h"
#if __APPLE__
typedef unsigned long ulong;
#endif
#include "tokudb_card.h"

static uint32_t hton32(uint32_t n) {
#if BYTE_ORDER == LITTLE_ENDIAN
    return __builtin_bswap32(n);
#else
    return n;
#endif
}

struct key {
    uint32_t r;
    uint32_t seq;
}; //  __attribute__((packed));

struct val {
    uint32_t v0;
}; //  __attribute__((packed));

// load nrows into the db
static void load_db(DB_ENV *env, DB *db, uint32_t nrows, uint32_t maxrand) {
    DB_TXN *txn = NULL;
    int r = env->txn_begin(env, NULL, &txn, 0);
    assert(r == 0);

    DB_LOADER *loader = NULL;
    uint32_t db_flags[1] = { 0 };
    uint32_t dbt_flags[1] = { 0 };
    uint32_t loader_flags = 0;
    r = env->create_loader(env, txn, &loader, db, 1, &db, db_flags, dbt_flags, loader_flags);
    assert(r == 0);

    for (uint32_t seq = 0; seq < nrows ; seq++) {
        struct key k = { hton32(random() % maxrand), hton32(seq) };
        struct val v = { seq };
        DBT key = { .data = &k, .size = sizeof k };
        DBT val = { .data = &v, .size = sizeof v };
        r = loader->put(loader, &key, &val);
        assert(r == 0);
    }

    r = loader->close(loader);
    assert(r == 0);

    r = txn->commit(txn, 0);
    assert(r == 0);
}

static int analyze_key_compare(DB *db __attribute__((unused)), const DBT *a, const DBT *b, uint level) {
    assert(a->size == b->size);
    switch (level) {
    default:
        assert(0);
    case 1:
        return memcmp(a->data, b->data, sizeof (uint32_t));
    case 2:
        assert(a->size == sizeof (struct key));
        return memcmp(a->data, b->data, sizeof (struct key));
    }
}

static void test_card(DB_ENV *env, DB *db, uint64_t expect[]) {
    int r;
    
    DB_TXN *txn = NULL;
    r = env->txn_begin(env, NULL, &txn, 0);
    assert(r == 0);

    uint64_t num_key_parts = 2;
    uint64_t rec_per_key[num_key_parts];

    r = tokudb::analyze_card(db, txn, false, num_key_parts, rec_per_key, analyze_key_compare, NULL, NULL);
    assert(r == 0);

    assert(rec_per_key[0] == expect[0]);
    assert(rec_per_key[1] == expect[1]);

    r = txn->commit(txn, 0);
    assert(r == 0);
}

int main(int argc, char * const argv[]) {
    uint64_t nrows = 1000000;
    uint32_t maxrand = 10;
    for (int i = 1; i < argc; i++) {
        if (strcmp(argv[i], "--nrows") == 0 && i+1 < argc) {
            nrows = atoll(argv[++i]);
            continue;
        }
        if (strcmp(argv[i], "--maxrand") == 0 && i+1 < argc) {
            maxrand = atoi(argv[++i]);
            continue;
        }
    }

    int r;
    r = system("rm -rf " __FILE__ ".testdir");
    assert(r == 0);
    r = mkdir(__FILE__ ".testdir", S_IRWXU+S_IRWXG+S_IRWXO);
    assert(r == 0);

    DB_ENV *env = NULL;
    r = db_env_create(&env, 0);
    assert(r == 0);

    r = env->open(env, __FILE__ ".testdir", DB_INIT_MPOOL + DB_INIT_LOG + DB_INIT_LOCK + DB_INIT_TXN + DB_PRIVATE + DB_CREATE, S_IRWXU+S_IRWXG+S_IRWXO); 
    assert(r == 0);

    // create the db
    DB *db = NULL;
    r = db_create(&db, env, 0);
    assert(r == 0);

    r = db->open(db, NULL, "test.db", 0, DB_BTREE, DB_CREATE + DB_AUTO_COMMIT, S_IRWXU+S_IRWXG+S_IRWXO);
    assert(r == 0);

    // load the db
    load_db(env, db, nrows, maxrand);

    uint64_t expect[2] = { nrows/maxrand, 1 };
    test_card(env, db, expect);

    r = db->close(db, 0);
    assert(r == 0);

    r = env->close(env, 0);
    assert(r == 0);

    return 0;
}