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#include "map/gps_track_storage.hpp"
#include "coding/endianness.hpp"
#include "coding/internal/file_data.hpp"
#include "std/algorithm.hpp"
#include "std/cstring.hpp"
#include "base/assert.hpp"
#include "base/logging.hpp"
namespace
{
// Current file format version
uint32_t constexpr kCurrentVersion = 1;
// Header size in bytes, header consists of uint32_t 'version' only
uint32_t constexpr kHeaderSize = sizeof(uint32_t);
// Number of items for batch processing
size_t constexpr kItemBlockSize = 1000;
// TODO
// Now GpsInfo written as plain values, but values can be compressed.
// Size of point in bytes to write in file of read from file
size_t constexpr kPointSize = 8 * sizeof(double) + sizeof(uint8_t);
// Writes value in memory in LittleEndian
template <typename T>
void MemWrite(void * ptr, T value)
{
value = SwapIfBigEndianMacroBased(value);
memcpy(ptr, &value, sizeof(T));
}
// Read value from memory, which is LittleEndian in memory
template <typename T>
T MemRead(void const * ptr)
{
T value;
memcpy(&value, ptr, sizeof(T));
return SwapIfBigEndianMacroBased(value);
}
void Pack(char * p, location::GpsInfo const & info)
{
MemWrite<double>(p + 0 * sizeof(double), info.m_timestamp);
MemWrite<double>(p + 1 * sizeof(double), info.m_latitude);
MemWrite<double>(p + 2 * sizeof(double), info.m_longitude);
MemWrite<double>(p + 3 * sizeof(double), info.m_altitude);
MemWrite<double>(p + 4 * sizeof(double), info.m_speedMpS);
MemWrite<double>(p + 5 * sizeof(double), info.m_bearing);
MemWrite<double>(p + 6 * sizeof(double), info.m_horizontalAccuracy);
MemWrite<double>(p + 7 * sizeof(double), info.m_verticalAccuracy);
ASSERT_LESS_OR_EQUAL(static_cast<int>(info.m_source), 255, ());
uint8_t const source = static_cast<uint8_t>(info.m_source);
MemWrite<uint8_t>(p + 8 * sizeof(double), source);
}
void Unpack(char const * p, location::GpsInfo & info)
{
info.m_timestamp = MemRead<double>(p + 0 * sizeof(double));
info.m_latitude = MemRead<double>(p + 1 * sizeof(double));
info.m_longitude = MemRead<double>(p + 2 * sizeof(double));
info.m_altitude = MemRead<double>(p + 3 * sizeof(double));
info.m_speedMpS = MemRead<double>(p + 4 * sizeof(double));
info.m_bearing = MemRead<double>(p + 5 * sizeof(double));
info.m_horizontalAccuracy = MemRead<double>(p + 6 * sizeof(double));
info.m_verticalAccuracy = MemRead<double>(p + 7 * sizeof(double));
uint8_t const source = MemRead<uint8_t>(p + 8 * sizeof(double));
info.m_source = static_cast<location::TLocationSource>(source);
}
inline size_t GetItemOffset(size_t itemIndex)
{
return kHeaderSize + itemIndex * kPointSize;
}
inline size_t GetItemCount(size_t fileSize)
{
ASSERT_GREATER_OR_EQUAL(fileSize, kHeaderSize, ());
return (fileSize - kHeaderSize) / kPointSize;
}
inline bool WriteVersion(fstream & f, uint32_t version)
{
static_assert(kHeaderSize == sizeof(version), "");
version = SwapIfBigEndianMacroBased(version);
f.write(reinterpret_cast<char const *>(&version), kHeaderSize);
return f.good();
}
inline bool ReadVersion(fstream & f, uint32_t & version)
{
static_assert(kHeaderSize == sizeof(version), "");
f.read(reinterpret_cast<char *>(&version), kHeaderSize);
version = SwapIfBigEndianMacroBased(version);
return f.good();
}
} // namespace
GpsTrackStorage::GpsTrackStorage(string const & filePath, size_t maxItemCount)
: m_filePath(filePath)
, m_maxItemCount(maxItemCount)
, m_itemCount(0)
{
ASSERT_GREATER(m_maxItemCount, 0, ());
// Open existing file
m_stream.open(m_filePath, ios::in | ios::out | ios::binary);
if (m_stream)
{
uint32_t version = 0;
if (!ReadVersion(m_stream, version))
MYTHROW(OpenException, ("Read version error.", m_filePath));
if (version == kCurrentVersion)
{
// Seek to end to get file size
m_stream.seekp(0, ios::end);
if (!m_stream.good())
MYTHROW(OpenException, ("Seek to the end error.", m_filePath));
auto const fileSize = static_cast<size_t>(m_stream.tellp());
m_itemCount = GetItemCount(fileSize);
// Set write position after last item position
size_t const offset = GetItemOffset(m_itemCount);
m_stream.seekp(offset, ios::beg);
if (!m_stream.good())
MYTHROW(OpenException, ("Seek to the offset error:", offset, m_filePath));
}
else
{
m_stream.close();
// TODO: migration for file m_filePath from version 'version' to version 'kCurrentVersion'
// TODO: For now we support only one version, but in future migration may be needed.
}
}
if (!m_stream)
{
// Create new file
m_stream.open(m_filePath, ios::in | ios::out | ios::binary | ios::trunc);
if (!m_stream)
MYTHROW(OpenException, ("Open file error.", m_filePath));
if (!WriteVersion(m_stream, kCurrentVersion))
MYTHROW(OpenException, ("Write version error.", m_filePath));
m_itemCount = 0;
}
}
void GpsTrackStorage::Append(vector<TItem> const & items)
{
ASSERT(m_stream.is_open(), ());
if (items.empty())
return;
bool const needTrunc = (m_itemCount + items.size()) > (m_maxItemCount * 2); // see NOTE in declaration
if (needTrunc)
TruncFile();
// Write position must be after last item position
ASSERT_EQUAL(m_stream.tellp(), static_cast<typename fstream::pos_type>(
GetItemOffset(m_itemCount)), ());
vector<char> buff(min(kItemBlockSize, items.size()) * kPointSize);
for (size_t i = 0; i < items.size();)
{
size_t const n = min(items.size() - i, kItemBlockSize);
for (size_t j = 0; j < n; ++j)
Pack(&buff[0] + j * kPointSize, items[i + j]);
m_stream.write(&buff[0], n * kPointSize);
if (!m_stream.good())
MYTHROW(WriteException, ("File:", m_filePath));
i += n;
}
m_stream.flush();
if (!m_stream.good())
MYTHROW(WriteException, ("File:", m_filePath));
m_itemCount += items.size();
}
void GpsTrackStorage::Clear()
{
ASSERT(m_stream.is_open(), ());
m_itemCount = 0;
m_stream.close();
m_stream.open(m_filePath, ios::in | ios::out | ios::binary | ios::trunc);
if (!m_stream)
MYTHROW(WriteException, ("File:", m_filePath));
if (!WriteVersion(m_stream, kCurrentVersion))
MYTHROW(WriteException, ("File:", m_filePath));
// Write position is set to the first item in the file
ASSERT_EQUAL(m_stream.tellp(), static_cast<typename fstream::pos_type>(
GetItemOffset(0)), ());
}
void GpsTrackStorage::ForEach(std::function<bool(TItem const & item)> const & fn)
{
ASSERT(m_stream.is_open(), ());
size_t i = GetFirstItemIndex();
// Set read position to the first item
m_stream.seekg(GetItemOffset(i), ios::beg);
if (!m_stream.good())
MYTHROW(ReadException, ("File:", m_filePath));
vector<char> buff(min(kItemBlockSize, m_itemCount) * kPointSize);
for (; i < m_itemCount;)
{
size_t const n = min(m_itemCount - i, kItemBlockSize);
m_stream.read(&buff[0], n * kPointSize);
if (!m_stream.good())
MYTHROW(ReadException, ("File:", m_filePath));
for (size_t j = 0; j < n; ++j)
{
TItem item;
Unpack(&buff[0] + j * kPointSize, item);
if (!fn(item))
return;
}
i += n;
}
}
void GpsTrackStorage::TruncFile()
{
string const tmpFilePath = m_filePath + ".tmp";
// Create a tmp file
fstream tmp(tmpFilePath, ios::in | ios::out | ios::binary | ios::trunc);
if (!tmp)
MYTHROW(WriteException, ("Unable to create temporary file:", tmpFilePath));
if (!WriteVersion(tmp, kCurrentVersion))
MYTHROW(WriteException, ("File:", tmpFilePath));
size_t i = GetFirstItemIndex();
// Set read position to the first item
m_stream.seekg(GetItemOffset(i), ios::beg);
if (!m_stream.good())
MYTHROW(ReadException, ("File:", m_filePath));
size_t newItemCount = 0;
// Copy items
vector<char> buff(min(kItemBlockSize, m_itemCount) * kPointSize);
for (; i < m_itemCount;)
{
size_t const n = min(m_itemCount - i, kItemBlockSize);
m_stream.read(&buff[0], n * kPointSize);
if (!m_stream.good())
MYTHROW(ReadException, ("File:", m_filePath));
tmp.write(&buff[0], n * kPointSize);
if (!tmp.good())
MYTHROW(WriteException, ("File:", tmpFilePath));
i += n;
newItemCount += n;
}
buff.clear();
buff.shrink_to_fit();
tmp.close();
m_stream.close();
// Replace file
if (!base::DeleteFileX(m_filePath) ||
!base::RenameFileX(tmpFilePath, m_filePath))
{
MYTHROW(WriteException, ("File:", m_filePath));
}
// Reopen stream
m_stream.open(m_filePath, ios::in | ios::out | ios::binary | ios::ate);
if (!m_stream)
MYTHROW(WriteException, ("File:", m_filePath));
m_itemCount = newItemCount;
// Write position must be after last item position (end of file)
ASSERT_EQUAL(m_stream.tellp(), static_cast<typename fstream::pos_type>(
GetItemOffset(m_itemCount)), ());
}
size_t GpsTrackStorage::GetFirstItemIndex() const
{
return (m_itemCount > m_maxItemCount) ? (m_itemCount - m_maxItemCount) : 0; // see NOTE in declaration
}
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