Files
hpcore/src/util.cpp
Asanka Indrajith d6acee4e09 Basic consensus implementation (#45)
Consensus for user connections, user inputs, contract outputs and time.
2019-10-26 11:46:32 -04:00

112 lines
2.8 KiB
C++

#include <string>
#include <sodium.h>
#include <sstream>
#include <chrono>
#include <rapidjson/document.h>
namespace util
{
/**
* Encodes provided bytes to hex string.
*
* @param encoded_string String reference to assign the hex encoded output.
* @param bin Bytes to encode.
* @param bin_len Bytes length.
* @return Always returns 0.
*/
int bin2hex(std::string &encoded_string, const unsigned char *bin, size_t bin_len)
{
// Allocate the target string.
encoded_string.resize(bin_len * 2);
// Get encoded string.
sodium_bin2hex(
encoded_string.data(),
encoded_string.length() + 1, // + 1 because sodium writes ending '\0' character as well.
bin,
bin_len);
return 0;
}
/**
* Decodes provided hex string into bytes.
*
* @param decodedbuf Buffer to assign decoded bytes.
* @param decodedbuf_len Decoded buffer size.
* @param hex_str hex string to decode.
*/
int hex2bin(unsigned char *decodedbuf, size_t decodedbuf_len, std::string_view hex_str)
{
const char *hex_end;
size_t bin_len;
if (sodium_hex2bin(
decodedbuf, decodedbuf_len,
hex_str.data(),
hex_str.length(),
"", &bin_len, &hex_end))
{
return -1;
}
return 0;
}
/**
* Returns current time in UNIX epoch milliseconds.
*/
int64_t get_epoch_milliseconds()
{
return std::chrono::duration_cast<std::chrono::milliseconds>(
std::chrono::system_clock::now().time_since_epoch())
.count();
}
/**
* Compare two version strings in the format of "1.12.3".
* v1 < v2 -> returns -1
* v1 == v2 -> returns 0
* v1 > v2 -> returns +1
* Error -> returns -2
*
* Remark on string_view: In other places of the code-base we utilize string_view
* to pass immutable string references around. However in this function we keep the 'const string&'
* syntax because istringstream doesn't support string_view. It's not worth optmising
* this code as it's not being used in high-scale processing.
*/
int version_compare(const std::string &x, const std::string &y)
{
std::istringstream ix(x), iy(y);
while (ix.good() || iy.good())
{
int cx = 0, cy = 0;
ix >> cx;
iy >> cy;
if ((!ix.eof() && !ix.good()) || (!iy.eof() && !iy.good()))
return -2;
if (cx > cy)
return 1;
if (cx < cy)
return -1;
ix.ignore();
iy.ignore();
}
return 0;
}
/**
* Returns a std::string_view pointing to the rapidjson Value which is assumed
* to be a string. We use this function because rapidjson does not have build-in string_view
* support. Passing a non-string 'v' is not supported.
*/
std::string_view getsv(const rapidjson::Value &v)
{
return std::string_view(v.GetString(), v.GetStringLength());
}
} // namespace util