polardbxengine/unittest/gunit/filesort_buffer-t.cc

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#include <gtest/gtest.h>
#include <stddef.h>
#include <sys/types.h>
#include <utility>

#include "my_inttypes.h"
#include "my_pointer_arithmetic.h"
#include "sql/filesort_utils.h"
#include "sql/table.h"

namespace filesort_buffer_unittest {

class FileSortBufferTest : public ::testing::Test {
 protected:
  virtual void TearDown() {
    fs_info.free_sort_buffer();
    EXPECT_TRUE(nullptr == fs_info.get_sort_keys());
  }

  Filesort_buffer fs_info;
};

TEST_F(FileSortBufferTest, Basic) {
  const char letters[10] = "abcdefghi";  // Zero-terminated.

  fs_info.set_max_size(32768, 10);
  for (uint ix = 0; ix < 10; ++ix) {
    Bounds_checked_array<uchar> buf = fs_info.get_next_record_pointer(10);
    ASSERT_GE(buf.size(), 10);
    memcpy(buf.array(), letters, 10);
    fs_info.commit_used_memory(10);
  }
  uchar **data = fs_info.get_sort_keys();
  for (uint ix = 0; ix < 10; ++ix) {
    const char *str = reinterpret_cast<const char *>(data[ix]);
    EXPECT_STREQ(letters, str);
  }

  EXPECT_GE(fs_info.peak_memory_used(), 100);
}

TEST_F(FileSortBufferTest, SizeNotGivenUpFront) {
  const char letters[10] = "abcdefghi";  // Zero-terminated.
  bool ever_given_too_little = false;

  fs_info.set_max_size(10485760, 10);
  for (uint ix = 0; ix < 10000; ++ix) {
    Bounds_checked_array<uchar> buf;
    size_t min_size = 1;
    for (;;)  // Termination condition within loop.
    {
      buf = fs_info.get_next_record_pointer(min_size);
      ASSERT_GE(buf.size(), min_size);
      if (buf.size() >= 10) break;
      ever_given_too_little = true;
      min_size = buf.size() + 1;
    }
    memcpy(buf.array(), letters, 10);
    fs_info.commit_used_memory(10);
  }

  /*
    Since MIN_SORT_MEMORY (32768) is not divisible by 10, we should get a
    record that's too small (8 bytes long, actually) at least once.
  */
  EXPECT_TRUE(ever_given_too_little);

  uchar **data = fs_info.get_sort_keys();
  for (uint ix = 0; ix < 10000; ++ix) {
    const char *str = reinterpret_cast<const char *>(data[ix]);
    EXPECT_STREQ(letters, str);
  }

  EXPECT_GE(fs_info.peak_memory_used(), 100000);
  EXPECT_LT(fs_info.peak_memory_used(), 1000000);
}

TEST_F(FileSortBufferTest, OneBigRecordFits) {
  /*
    Set the record size to maximum possible to ensure we don't
    estimate any space for record pointers. This is depending on an
    implementation detail; if the record pointer allocation gets
    smarter in the future, the test will have to be adjusted.
  */
  fs_info.set_max_size(10485760, 0xFFFFFFFFu);
  Bounds_checked_array<uchar> buf;
  size_t min_size = 1;
  for (;;)  // Termination condition within loop.
  {
    buf = fs_info.get_next_record_pointer(min_size);

    // Should increase by _more_ than just one byte each reallocation.
    ASSERT_GE(buf.size(), min_size + 1);

    if (buf.size() >= 10485760) break;
    min_size = buf.size() + 1;
  }

  EXPECT_EQ(10485760, buf.size());
}

TEST_F(FileSortBufferTest, RecordPointersGetReclaimed) {
  // Allocate tiny records until there is no more room.
  fs_info.set_max_size(300000, 1);
  Bounds_checked_array<uchar> buf;
  size_t num_records = 0;
  for (;;) {  // Termination condition within loop.
    buf = fs_info.get_next_record_pointer(1);
    if (buf.array() == nullptr) break;
    fs_info.commit_used_memory(1);
    ++num_records;
  }

  // Verify that we took record pointers into account.
  EXPECT_LT(num_records, 100000);

  fs_info.reset();

  /*
    Now we will have tons of record pointers that need to be reclaimed
    if we want to be able to to store 250 kB of large rows.
  */
  fs_info.set_max_size(300000, 10000);
  for (uint ix = 0; ix < 25; ++ix) {
    buf = fs_info.get_next_record_pointer(10000);
    EXPECT_NE(nullptr, buf.array());
    fs_info.commit_used_memory(10000);
  }
}

TEST_F(FileSortBufferTest, PreallocateRecords) {
  fs_info.set_max_size(32768, sizeof(char));
  fs_info.preallocate_records(10);
  uchar **ptr = fs_info.get_sort_keys();
  EXPECT_NE(nullptr, ptr);
  for (uint ix = 0; ix < 10 - 1; ++ix) {
    uchar **nxt = ptr + 1;
    EXPECT_EQ(1, *nxt - *ptr) << "index:" << ix;
    ++ptr;
  }
}

}  // namespace filesort_buffer_unittest