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#include "hash.hpp"
#include <extern/smhasher/MurmurHash3.h>
#include <array>
#include <cstdint>
#include <istream>
#include <string>
namespace Files
{
std::array<std::uint64_t, 2> getHash(std::string_view fileName, std::istream& stream)
{
std::array<std::uint64_t, 2> hash{ 0, 0 };
try
{
const auto start = stream.tellg();
const auto exceptions = stream.exceptions();
stream.exceptions(std::ios_base::badbit);
while (stream)
{
std::array<char, 4096> value;
stream.read(value.data(), value.size());
const std::streamsize read = stream.gcount();
if (read == 0)
break;
std::array<std::uint64_t, 2> blockHash{ 0, 0 };
MurmurHash3_x64_128(value.data(), static_cast<int>(read), hash.data(), blockHash.data());
hash = blockHash;
}
stream.clear();
stream.exceptions(exceptions);
stream.seekg(start);
}
catch (const std::exception& e)
{
std::string message = "Error while reading \"";
message += fileName;
message += "\" to get hash: ";
message += e.what();
throw std::runtime_error(message);
}
return hash;
}
}
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