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Make the block size of vector<bool> consistent

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This commit is contained in:
Patrick Niklaus
2018-03-23 12:02:20 +00:00
parent c0dd5d7c76
commit c322d93435
6 changed files with 49 additions and 39 deletions
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include/storage/serialization.hpp
+21 -17
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@@ -129,21 +129,21 @@ void write(tar::FileWriter &writer, const std::string &name, const util::vector_
namespace detail
{
template <typename T>
inline unsigned char packBits(const T &data, std::size_t index, std::size_t count)
template <typename T, typename BlockT = unsigned char>
inline BlockT packBits(const T &data, std::size_t index, std::size_t count)
{
static_assert(std::is_same<typename T::value_type, bool>::value, "value_type is not bool");
unsigned char value = 0;
BlockT value = 0;
for (std::size_t bit = 0; bit < count; ++bit, ++index)
value = (value << 1) | data[index];
return value;
}
template <typename T>
inline void unpackBits(T &data, std::size_t index, std::size_t count, unsigned char value)
template <typename T, typename BlockT = unsigned char>
inline void unpackBits(T &data, std::size_t index, std::size_t count, BlockT value)
{
static_assert(std::is_same<typename T::value_type, bool>::value, "value_type is not bool");
const unsigned char mask = 1 << (count - 1);
const BlockT mask = BlockT {1} << (count - 1);
for (std::size_t bit = 0; bit < count; value <<= 1, ++bit, ++index)
data[index] = value & mask;
}
@@ -155,13 +155,15 @@ void readBoolVector(tar::FileReader &reader, const std::string &name, VectorT &d
data.resize(count);
std::uint64_t index = 0;
const auto decode = [&](const unsigned char block) {
auto read_size = std::min<std::size_t>(count - index, CHAR_BIT);
unpackBits(data, index, read_size, block);
index += CHAR_BIT;
constexpr std::uint64_t WORD_BITS = CHAR_BIT * sizeof(std::uint64_t);
const auto decode = [&](const std::uint64_t block) {
auto read_size = std::min<std::size_t>(count - index, WORD_BITS);
unpackBits<VectorT,std::uint64_t>(data, index, read_size, block);
index += WORD_BITS;
};
reader.ReadStreaming<unsigned char>(name, boost::make_function_output_iterator(decode));
reader.ReadStreaming<std::uint64_t>(name, boost::make_function_output_iterator(decode));
}
template <typename VectorT>
@@ -171,17 +173,19 @@ void writeBoolVector(tar::FileWriter &writer, const std::string &name, const Vec
writer.WriteElementCount64(name, count);
std::uint64_t index = 0;
constexpr std::uint64_t WORD_BITS = CHAR_BIT * sizeof(std::uint64_t);
// FIXME on old boost version the function_input_iterator does not work with lambdas
// so we need to wrap it in a function here.
const std::function<char()> encode_function = [&]() -> char {
auto write_size = std::min<std::size_t>(count - index, CHAR_BIT);
auto packed = packBits(data, index, write_size);
index += CHAR_BIT;
const std::function<std::uint64_t()> encode_function = [&]() -> std::uint64_t {
auto write_size = std::min<std::size_t>(count - index, WORD_BITS);
auto packed = packBits<VectorT, std::uint64_t>(data, index, write_size);
index += WORD_BITS;
return packed;
};
std::uint64_t number_of_blocks = std::ceil((double)count / CHAR_BIT);
writer.WriteStreaming<unsigned char>(
std::uint64_t number_of_blocks = (count + WORD_BITS - 1) / WORD_BITS;
writer.WriteStreaming<std::uint64_t>(
name,
boost::make_function_input_iterator(encode_function, boost::infinite()),
number_of_blocks);