osrm-backend/include/storage/serialization.hpp
2017-10-04 10:03:42 +02:00

192 lines
6.2 KiB
C++

#ifndef OSRM_STORAGE_SERIALIZATION_HPP
#define OSRM_STORAGE_SERIALIZATION_HPP
#include "util/deallocating_vector.hpp"
#include "util/integer_range.hpp"
#include "util/vector_view.hpp"
#include "storage/io.hpp"
#include <cmath>
#include <cstdint>
#if USE_STXXL_LIBRARY
#include <stxxl/vector>
#endif
namespace osrm
{
namespace storage
{
namespace serialization
{
/* All vector formats here use the same on-disk format.
* This is important because we want to be able to write from a vector
* of one kind, but read it into a vector of another kind.
*
* All vector types with this guarantee should be placed in this file.
*/
template <typename T>
inline void read(storage::io::FileReader &reader, util::DeallocatingVector<T> &vec)
{
vec.current_size = reader.ReadElementCount64(vec.current_size);
std::size_t num_blocks =
std::ceil(vec.current_size / util::DeallocatingVector<T>::ELEMENTS_PER_BLOCK);
vec.bucket_list.resize(num_blocks);
// Read all but the last block which can be partital
for (auto bucket_index : util::irange<std::size_t>(0, num_blocks - 1))
{
vec.bucket_list[bucket_index] = new T[util::DeallocatingVector<T>::ELEMENTS_PER_BLOCK];
reader.ReadInto(vec.bucket_list[bucket_index],
util::DeallocatingVector<T>::ELEMENTS_PER_BLOCK);
}
std::size_t last_block_size =
vec.current_size % util::DeallocatingVector<T>::ELEMENTS_PER_BLOCK;
vec.bucket_list.back() = new T[util::DeallocatingVector<T>::ELEMENTS_PER_BLOCK];
reader.ReadInto(vec.bucket_list.back(), last_block_size);
}
template <typename T>
inline void write(storage::io::FileWriter &writer, const util::DeallocatingVector<T> &vec)
{
writer.WriteElementCount64(vec.current_size);
// Write all but the last block which can be partially filled
for (auto bucket_index : util::irange<std::size_t>(0, vec.bucket_list.size() - 1))
{
writer.WriteFrom(vec.bucket_list[bucket_index],
util::DeallocatingVector<T>::ELEMENTS_PER_BLOCK);
}
std::size_t last_block_size =
vec.current_size % util::DeallocatingVector<T>::ELEMENTS_PER_BLOCK;
writer.WriteFrom(vec.bucket_list.back(), last_block_size);
}
#if USE_STXXL_LIBRARY
template <typename T> inline void read(storage::io::FileReader &reader, stxxl::vector<T> &vec)
{
auto size = reader.ReadOne<std::uint64_t>();
vec.reserve(size);
for (auto idx : util::irange<std::size_t>(0, size))
{
(void)idx;
vec.push_back(reader.ReadOne<T>());
}
}
template <typename T>
inline void write(storage::io::FileWriter &writer, const stxxl::vector<T> &vec)
{
writer.WriteOne(vec.size());
for (auto idx : util::irange<std::size_t>(0, vec.size()))
{
writer.WriteOne<T>(vec[idx]);
}
}
#endif
template <typename T> void read(io::FileReader &reader, std::vector<T> &data)
{
const auto count = reader.ReadElementCount64();
data.resize(count);
reader.ReadInto(data.data(), count);
}
template <typename T> void write(io::FileWriter &writer, const std::vector<T> &data)
{
const auto count = data.size();
writer.WriteElementCount64(count);
writer.WriteFrom(data.data(), count);
}
template <typename T> void read(io::FileReader &reader, util::vector_view<T> &data)
{
const auto count = reader.ReadElementCount64();
BOOST_ASSERT(data.size() == count);
reader.ReadInto(data.data(), count);
}
template <typename T> void write(io::FileWriter &writer, const util::vector_view<T> &data)
{
const auto count = data.size();
writer.WriteElementCount64(count);
writer.WriteFrom(data.data(), count);
}
template <typename T>
inline unsigned char 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;
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)
{
static_assert(std::is_same<typename T::value_type, bool>::value, "value_type is not bool");
const unsigned char mask = 1 << (count - 1);
for (std::size_t bit = 0; bit < count; value <<= 1, ++bit, ++index)
data[index] = value & mask;
}
template <> inline void read<bool>(io::FileReader &reader, util::vector_view<bool> &data)
{
const auto count = reader.ReadElementCount64();
BOOST_ASSERT(data.size() == count);
std::uint64_t index = 0;
for (std::uint64_t next = CHAR_BIT; next < count; index = next, next += CHAR_BIT)
{
unpackBits(data, index, CHAR_BIT, reader.ReadOne<unsigned char>());
}
if (count > index)
unpackBits(data, index, count - index, reader.ReadOne<unsigned char>());
}
template <> inline void write<bool>(io::FileWriter &writer, const util::vector_view<bool> &data)
{
const auto count = data.size();
writer.WriteElementCount64(count);
std::uint64_t index = 0;
for (std::uint64_t next = CHAR_BIT; next < count; index = next, next += CHAR_BIT)
{
writer.WriteOne<unsigned char>(packBits(data, CHAR_BIT * index, CHAR_BIT));
}
if (count > index)
writer.WriteOne<unsigned char>(packBits(data, index, count - index));
}
template <> inline void read<bool>(io::FileReader &reader, std::vector<bool> &data)
{
const auto count = reader.ReadElementCount64();
data.resize(count);
std::uint64_t index = 0;
for (std::uint64_t next = CHAR_BIT; next < count; index = next, next += CHAR_BIT)
{
unpackBits(data, index, CHAR_BIT, reader.ReadOne<unsigned char>());
}
if (count > index)
unpackBits(data, index, count - index, reader.ReadOne<unsigned char>());
}
template <> inline void write<bool>(io::FileWriter &writer, const std::vector<bool> &data)
{
const auto count = data.size();
writer.WriteElementCount64(count);
std::uint64_t index = 0;
for (std::uint64_t next = CHAR_BIT; next < count; index = next, next += CHAR_BIT)
{
writer.WriteOne<unsigned char>(packBits(data, index, CHAR_BIT));
}
if (count > index)
writer.WriteOne<unsigned char>(packBits(data, index, count - index));
}
}
}
}
#endif