test-example-projects/c++_projects/280w-mysql-8.0.18/unittest/gunit/collation_loader-t.cc

/* Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

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   as designated in a particular file or component or in included license
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   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

/*
  We do benchmark test of character set loader below.
  1. Load a collation. This happens in query like 'SELECT a FROM tbl ORDER BY
     a COLLATE coll_name'. 'coll_name' is the name of collation which is used
     to do ordering, like 'latin1_swedish_ci'.
  2. Load a character set. In MySQL, when you ask for a 'character set', you
     actually get a collation. For example, when executing 'SELECT _utf16
     0x0100'. MySQL uses the pointer to collation 'utf16_general_ci' to handle
     this character.
*/

#include <gtest/gtest.h>
#include <thread>
#include <vector>

#include "m_ctype.h"
#include "my_sys.h"
#include "unittest/gunit/benchmark.h"

namespace collation_loader_unittest {

namespace {

CHARSET_INFO *lookup_collation(const char *name) {
  MY_CHARSET_LOADER loader;
  my_charset_loader_init_mysys(&loader);
  return my_collation_get_by_name(&loader, name, MYF(0));
}

CHARSET_INFO *lookup_charset(const char *name, int flag) {
  MY_CHARSET_LOADER loader;
  my_charset_loader_init_mysys(&loader);
  return my_charset_get_by_name(&loader, name, flag, MYF(0));
}

}  // namespace

static void BM_LookupAllCollations(size_t num_iterations) {
  StopBenchmarkTiming();

  // Look up one collation to initialize the all_charsets array.
  lookup_collation("latin1_swedish_ci");
  size_t num_charsets = array_elements(all_charsets);

  StartBenchmarkTiming();
  for (size_t i = 0; i < num_iterations; i++) {
    const CHARSET_INFO *cs = all_charsets[i % num_charsets];
    if (cs) {
      EXPECT_NE(lookup_collation(cs->name), nullptr);
    }
  }
}
BENCHMARK(BM_LookupAllCollations)

static std::vector<std::string> charsets = {
    "armscii8", "ascii",   "big5",   "binary",  "cp1250",  "cp1251",
    "cp1256",   "cp1257",  "cp850",  "cp852",   "cp866",   "cp932",
    "dec8",     "eucjpms", "euckr",  "gb18030", "gb2312",  "gbk",
    "geostd8",  "greek",   "hebrew", "hp8",     "keybcs2", "koi8r",
    "koi8u",    "latin1",  "latin2", "latin5",  "latin7",  "macce",
    "macroman", "sjis",    "swe7",   "tis620",  "ucs2",    "ujis",
    "utf16",    "utf16le", "utf32",  "utf8",    "utf8mb4",
};

static void BM_LookupAllCharsets(size_t num_iterations) {
  StopBenchmarkTiming();

  // Look up one collation to initialize the all_charsets array.
  lookup_collation("latin1_swedish_ci");

  StartBenchmarkTiming();
  for (size_t i = 0; i < num_iterations; i++) {
    const std::string &charset = charsets[i % charsets.size()];
    EXPECT_NE(lookup_charset(charset.c_str(), MY_CS_PRIMARY), nullptr);
    EXPECT_NE(lookup_charset(charset.c_str(), MY_CS_BINSORT), nullptr);
  }
}
BENCHMARK(BM_LookupAllCharsets)

void TestRandomCollation() {
  char coll_name[65];
  for (int i = 0; i < 100000; i++) {
    memset(coll_name, 0, 65);
    // Generate a random collation name whose length is in range [1, 64].
    size_t random_coll_name_len = 1 + rand() % 64;
    for (size_t i = 0; i < random_coll_name_len; i++) {
      // Use ASCII latin letters to generate the name.
      coll_name[i] = 'a' + rand() % 26;
    }
    int rc = get_collation_number(coll_name);
    // Random collation that doesn't exist should return 0.
    EXPECT_EQ(0, rc);
  }
}

TEST(CollationLoaderTest, RandomCollation) {
  // Look up one collation to initialize the all_charsets array.
  lookup_collation("latin1_swedish_ci");
  std::thread test_thd[4];
  for (int i = 0; i < 4; i++) test_thd[i] = std::thread(TestRandomCollation);
  for (int i = 0; i < 4; i++) test_thd[i].join();
}
}  // namespace collation_loader_unittest