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RColumnElement.cxx
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1 /// \file RColumnElement.cxx
2 /// \ingroup NTuple ROOT7
3 /// \author Jakob Blomer <jblomer@cern.ch>
4 /// \date 2019-08-11
5 /// \warning This is part of the ROOT 7 prototype! It will change without notice. It might trigger earthquakes. Feedback
6 /// is welcome!
7 
8 /*************************************************************************
9  * Copyright (C) 1995-2019, Rene Brun and Fons Rademakers. *
10  * All rights reserved. *
11  * *
12  * For the licensing terms see $ROOTSYS/LICENSE. *
13  * For the list of contributors see $ROOTSYS/README/CREDITS. *
14  *************************************************************************/
15 
16 #include <ROOT/RColumnElement.hxx>
17 
18 #include <TError.h>
19 
20 #include <algorithm>
21 #include <bitset>
22 #include <cstdint>
23 
24 ROOT::Experimental::Detail::RColumnElementBase
25 ROOT::Experimental::Detail::RColumnElementBase::Generate(EColumnType type) {
26  switch (type) {
27  case EColumnType::kReal32:
28  return RColumnElement<float, EColumnType::kReal32>(nullptr);
29  case EColumnType::kReal64:
30  return RColumnElement<double, EColumnType::kReal64>(nullptr);
31  case EColumnType::kByte:
32  return RColumnElement<std::uint8_t, EColumnType::kByte>(nullptr);
33  case EColumnType::kInt32:
34  return RColumnElement<std::int32_t, EColumnType::kInt32>(nullptr);
35  case EColumnType::kInt64:
36  return RColumnElement<std::int64_t, EColumnType::kInt64>(nullptr);
37  case EColumnType::kBit:
38  return RColumnElement<bool, EColumnType::kBit>(nullptr);
39  case EColumnType::kIndex:
40  return RColumnElement<ClusterSize_t, EColumnType::kIndex>(nullptr);
41  case EColumnType::kSwitch:
42  return RColumnElement<RColumnSwitch, EColumnType::kSwitch>(nullptr);
43  default:
44  R__ASSERT(false);
45  }
46  // never here
47  return RColumnElementBase();
48 }
49 
50 void ROOT::Experimental::Detail::RColumnElement<bool, ROOT::Experimental::EColumnType::kBit>::Pack(
51  void *dst, void *src, std::size_t count) const
52 {
53  bool *boolArray = reinterpret_cast<bool *>(src);
54  char *charArray = reinterpret_cast<char *>(dst);
55  std::bitset<8> bitSet;
56  std::size_t i = 0;
57  for (; i < count; ++i) {
58  bitSet.set(i % 8, boolArray[i]);
59  if (i % 8 == 7) {
60  char packed = bitSet.to_ulong();
61  charArray[i / 8] = packed;
62  }
63  }
64  if (i % 8 != 0) {
65  char packed = bitSet.to_ulong();
66  charArray[i / 8] = packed;
67  }
68 }
69 
70 void ROOT::Experimental::Detail::RColumnElement<bool, ROOT::Experimental::EColumnType::kBit>::Unpack(
71  void *dst, void *src, std::size_t count) const
72 {
73  bool *boolArray = reinterpret_cast<bool *>(dst);
74  char *charArray = reinterpret_cast<char *>(src);
75  std::bitset<8> bitSet;
76  for (std::size_t i = 0; i < count; i += 8) {
77  bitSet = charArray[i / 8];
78  for (std::size_t j = i; j < std::min(count, i + 8); ++j) {
79  boolArray[j] = bitSet[j % 8];
80  }
81  }
82 }