in AirLib/include/common/common_utils/json.hpp [7448:7916]
static basic_json from_cbor_internal(const std::vector<uint8_t>& v, size_t& idx)
{
// store and increment index
const size_t current_idx = idx++;
switch (v.at(current_idx))
{
// Integer 0x00..0x17 (0..23)
case 0x00:
case 0x01:
case 0x02:
case 0x03:
case 0x04:
case 0x05:
case 0x06:
case 0x07:
case 0x08:
case 0x09:
case 0x0a:
case 0x0b:
case 0x0c:
case 0x0d:
case 0x0e:
case 0x0f:
case 0x10:
case 0x11:
case 0x12:
case 0x13:
case 0x14:
case 0x15:
case 0x16:
case 0x17:
{
return v[current_idx];
}
case 0x18: // Unsigned integer (one-byte uint8_t follows)
{
idx += 1; // skip content byte
return get_from_vector<uint8_t>(v, current_idx);
}
case 0x19: // Unsigned integer (two-byte uint16_t follows)
{
idx += 2; // skip 2 content bytes
return get_from_vector<uint16_t>(v, current_idx);
}
case 0x1a: // Unsigned integer (four-byte uint32_t follows)
{
idx += 4; // skip 4 content bytes
return get_from_vector<uint32_t>(v, current_idx);
}
case 0x1b: // Unsigned integer (eight-byte uint64_t follows)
{
idx += 8; // skip 8 content bytes
return get_from_vector<uint64_t>(v, current_idx);
}
// Negative integer -1-0x00..-1-0x17 (-1..-24)
case 0x20:
case 0x21:
case 0x22:
case 0x23:
case 0x24:
case 0x25:
case 0x26:
case 0x27:
case 0x28:
case 0x29:
case 0x2a:
case 0x2b:
case 0x2c:
case 0x2d:
case 0x2e:
case 0x2f:
case 0x30:
case 0x31:
case 0x32:
case 0x33:
case 0x34:
case 0x35:
case 0x36:
case 0x37:
{
return static_cast<int8_t>(0x20 - 1 - v[current_idx]);
}
case 0x38: // Negative integer (one-byte uint8_t follows)
{
idx += 1; // skip content byte
// must be uint8_t !
return static_cast<number_integer_t>(-1) - get_from_vector<uint8_t>(v, current_idx);
}
case 0x39: // Negative integer -1-n (two-byte uint16_t follows)
{
idx += 2; // skip 2 content bytes
return static_cast<number_integer_t>(-1) - get_from_vector<uint16_t>(v, current_idx);
}
case 0x3a: // Negative integer -1-n (four-byte uint32_t follows)
{
idx += 4; // skip 4 content bytes
return static_cast<number_integer_t>(-1) - get_from_vector<uint32_t>(v, current_idx);
}
case 0x3b: // Negative integer -1-n (eight-byte uint64_t follows)
{
idx += 8; // skip 8 content bytes
return static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(get_from_vector<uint64_t>(v, current_idx));
}
// UTF-8 string (0x00..0x17 bytes follow)
case 0x60:
case 0x61:
case 0x62:
case 0x63:
case 0x64:
case 0x65:
case 0x66:
case 0x67:
case 0x68:
case 0x69:
case 0x6a:
case 0x6b:
case 0x6c:
case 0x6d:
case 0x6e:
case 0x6f:
case 0x70:
case 0x71:
case 0x72:
case 0x73:
case 0x74:
case 0x75:
case 0x76:
case 0x77:
{
const auto len = static_cast<size_t>(v[current_idx] - 0x60);
const size_t offset = current_idx + 1;
idx += len; // skip content bytes
check_length(v.size(), len, offset);
return std::string(reinterpret_cast<const char*>(v.data()) + offset, len);
}
case 0x78: // UTF-8 string (one-byte uint8_t for n follows)
{
const auto len = static_cast<size_t>(get_from_vector<uint8_t>(v, current_idx));
const size_t offset = current_idx + 2;
idx += len + 1; // skip size byte + content bytes
check_length(v.size(), len, offset);
return std::string(reinterpret_cast<const char*>(v.data()) + offset, len);
}
case 0x79: // UTF-8 string (two-byte uint16_t for n follow)
{
const auto len = static_cast<size_t>(get_from_vector<uint16_t>(v, current_idx));
const size_t offset = current_idx + 3;
idx += len + 2; // skip 2 size bytes + content bytes
check_length(v.size(), len, offset);
return std::string(reinterpret_cast<const char*>(v.data()) + offset, len);
}
case 0x7a: // UTF-8 string (four-byte uint32_t for n follow)
{
const auto len = static_cast<size_t>(get_from_vector<uint32_t>(v, current_idx));
const size_t offset = current_idx + 5;
idx += len + 4; // skip 4 size bytes + content bytes
check_length(v.size(), len, offset);
return std::string(reinterpret_cast<const char*>(v.data()) + offset, len);
}
case 0x7b: // UTF-8 string (eight-byte uint64_t for n follow)
{
const auto len = static_cast<size_t>(get_from_vector<uint64_t>(v, current_idx));
const size_t offset = current_idx + 9;
idx += len + 8; // skip 8 size bytes + content bytes
check_length(v.size(), len, offset);
return std::string(reinterpret_cast<const char*>(v.data()) + offset, len);
}
case 0x7f: // UTF-8 string (indefinite length)
{
std::string result;
while (v.at(idx) != 0xff)
{
string_t s = from_cbor_internal(v, idx);
result += s;
}
// skip break byte (0xFF)
idx += 1;
return result;
}
// array (0x00..0x17 data items follow)
case 0x80:
case 0x81:
case 0x82:
case 0x83:
case 0x84:
case 0x85:
case 0x86:
case 0x87:
case 0x88:
case 0x89:
case 0x8a:
case 0x8b:
case 0x8c:
case 0x8d:
case 0x8e:
case 0x8f:
case 0x90:
case 0x91:
case 0x92:
case 0x93:
case 0x94:
case 0x95:
case 0x96:
case 0x97:
{
basic_json result = value_t::array;
const auto len = static_cast<size_t>(v[current_idx] - 0x80);
for (size_t i = 0; i < len; ++i)
{
result.push_back(from_cbor_internal(v, idx));
}
return result;
}
case 0x98: // array (one-byte uint8_t for n follows)
{
basic_json result = value_t::array;
const auto len = static_cast<size_t>(get_from_vector<uint8_t>(v, current_idx));
idx += 1; // skip 1 size byte
for (size_t i = 0; i < len; ++i)
{
result.push_back(from_cbor_internal(v, idx));
}
return result;
}
case 0x99: // array (two-byte uint16_t for n follow)
{
basic_json result = value_t::array;
const auto len = static_cast<size_t>(get_from_vector<uint16_t>(v, current_idx));
idx += 2; // skip 4 size bytes
for (size_t i = 0; i < len; ++i)
{
result.push_back(from_cbor_internal(v, idx));
}
return result;
}
case 0x9a: // array (four-byte uint32_t for n follow)
{
basic_json result = value_t::array;
const auto len = static_cast<size_t>(get_from_vector<uint32_t>(v, current_idx));
idx += 4; // skip 4 size bytes
for (size_t i = 0; i < len; ++i)
{
result.push_back(from_cbor_internal(v, idx));
}
return result;
}
case 0x9b: // array (eight-byte uint64_t for n follow)
{
basic_json result = value_t::array;
const auto len = static_cast<size_t>(get_from_vector<uint64_t>(v, current_idx));
idx += 8; // skip 8 size bytes
for (size_t i = 0; i < len; ++i)
{
result.push_back(from_cbor_internal(v, idx));
}
return result;
}
case 0x9f: // array (indefinite length)
{
basic_json result = value_t::array;
while (v.at(idx) != 0xff)
{
result.push_back(from_cbor_internal(v, idx));
}
// skip break byte (0xFF)
idx += 1;
return result;
}
// map (0x00..0x17 pairs of data items follow)
case 0xa0:
case 0xa1:
case 0xa2:
case 0xa3:
case 0xa4:
case 0xa5:
case 0xa6:
case 0xa7:
case 0xa8:
case 0xa9:
case 0xaa:
case 0xab:
case 0xac:
case 0xad:
case 0xae:
case 0xaf:
case 0xb0:
case 0xb1:
case 0xb2:
case 0xb3:
case 0xb4:
case 0xb5:
case 0xb6:
case 0xb7:
{
basic_json result = value_t::object;
const auto len = static_cast<size_t>(v[current_idx] - 0xa0);
for (size_t i = 0; i < len; ++i)
{
std::string key = from_cbor_internal(v, idx);
result[key] = from_cbor_internal(v, idx);
}
return result;
}
case 0xb8: // map (one-byte uint8_t for n follows)
{
basic_json result = value_t::object;
const auto len = static_cast<size_t>(get_from_vector<uint8_t>(v, current_idx));
idx += 1; // skip 1 size byte
for (size_t i = 0; i < len; ++i)
{
std::string key = from_cbor_internal(v, idx);
result[key] = from_cbor_internal(v, idx);
}
return result;
}
case 0xb9: // map (two-byte uint16_t for n follow)
{
basic_json result = value_t::object;
const auto len = static_cast<size_t>(get_from_vector<uint16_t>(v, current_idx));
idx += 2; // skip 2 size bytes
for (size_t i = 0; i < len; ++i)
{
std::string key = from_cbor_internal(v, idx);
result[key] = from_cbor_internal(v, idx);
}
return result;
}
case 0xba: // map (four-byte uint32_t for n follow)
{
basic_json result = value_t::object;
const auto len = static_cast<size_t>(get_from_vector<uint32_t>(v, current_idx));
idx += 4; // skip 4 size bytes
for (size_t i = 0; i < len; ++i)
{
std::string key = from_cbor_internal(v, idx);
result[key] = from_cbor_internal(v, idx);
}
return result;
}
case 0xbb: // map (eight-byte uint64_t for n follow)
{
basic_json result = value_t::object;
const auto len = static_cast<size_t>(get_from_vector<uint64_t>(v, current_idx));
idx += 8; // skip 8 size bytes
for (size_t i = 0; i < len; ++i)
{
std::string key = from_cbor_internal(v, idx);
result[key] = from_cbor_internal(v, idx);
}
return result;
}
case 0xbf: // map (indefinite length)
{
basic_json result = value_t::object;
while (v.at(idx) != 0xff)
{
std::string key = from_cbor_internal(v, idx);
result[key] = from_cbor_internal(v, idx);
}
// skip break byte (0xFF)
idx += 1;
return result;
}
case 0xf4: // false
{
return false;
}
case 0xf5: // true
{
return true;
}
case 0xf6: // null
{
return value_t::null;
}
case 0xf9: // Half-Precision Float (two-byte IEEE 754)
{
idx += 2; // skip two content bytes
// code from RFC 7049, Appendix D, Figure 3:
// As half-precision floating-point numbers were only added to
// IEEE 754 in 2008, today's programming platforms often still
// only have limited support for them. It is very easy to
// include at least decoding support for them even without such
// support. An example of a small decoder for half-precision
// floating-point numbers in the C language is shown in Fig. 3.
const int half = (v.at(current_idx + 1) << 8) + v.at(current_idx + 2);
const int exp = (half >> 10) & 0x1f;
const int mant = half & 0x3ff;
double val;
if (exp == 0)
{
val = std::ldexp(mant, -24);
}
else if (exp != 31)
{
val = std::ldexp(mant + 1024, exp - 25);
}
else
{
val = mant == 0
? std::numeric_limits<double>::infinity()
: std::numeric_limits<double>::quiet_NaN();
}
return (half & 0x8000) != 0 ? -val : val;
}
case 0xfa: // Single-Precision Float (four-byte IEEE 754)
{
// copy bytes in reverse order into the float variable
float res;
for (size_t byte = 0; byte < sizeof(float); ++byte)
{
reinterpret_cast<uint8_t*>(&res)[sizeof(float) - byte - 1] = v.at(current_idx + 1 + byte);
}
idx += sizeof(float); // skip content bytes
return res;
}
case 0xfb: // Double-Precision Float (eight-byte IEEE 754)
{
// copy bytes in reverse order into the double variable
double res;
for (size_t byte = 0; byte < sizeof(double); ++byte)
{
reinterpret_cast<uint8_t*>(&res)[sizeof(double) - byte - 1] = v.at(current_idx + 1 + byte);
}
idx += sizeof(double); // skip content bytes
return res;
}
default: // anything else (0xFF is handled inside the other types)
{
JSON_THROW(std::invalid_argument("error parsing a CBOR @ " + std::to_string(current_idx) + ": " + std::to_string(static_cast<int>(v[current_idx]))));
}
}
}