Function testAllAlignment

cachelib/common/tests/BytesEqualTest.cpp:51–81

}

void testAllAlignment(bool equal) {
  auto d = generateRandomString();
  auto a = d;
  a.reserve(kMaxKeySize + 8);
  // ensure we checked all possible alignments
  uint64_t byte_align = 0;
  // we care about 0 - 8 byte alignment.
  for (int i = 0; i < 8; i++) {
    // push a's alignment by this many bytes by padding in the front.
    if (i != 0) {
      a.insert(a.begin(), 'X');
    }
    const int aAlign = ((uintptr_t)(void*)&a[i]) % 8;
    auto b = equal ? d : generateRandomString();
    b.reserve(kMaxKeySize + 8);
    for (int j = 0; j < 8; j++) {
      // push a's alignment by this many bytes by padding in the front.
      if (j != 0) {
        b.insert(b.begin(), 'X');
      }
      const int bAlign = ((uintptr_t)(void*)&b[j]) % 8;
      byte_align |= (1ULL << (aAlign * 8 + bAlign));
      for (int len = 0; len < kMaxKeySize; len++) {
        // a has been pushed by i bytes and b has been pushed by j bytes from
        // their default 1 byte aligned locations.
        checkCorrectness(&a[i], &b[j], len);
      }
    }
  }
  ASSERT_EQ(byte_align, std::numeric_limits<uint64_t>::max());
}

TEST(bytesEqual, alignment_equal) { testAllAlignment(true); }