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[ox/mc] Use VLI encoding for integers

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This commit is contained in:
Gary Talent
2019-03-17 03:03:21 -05:00
parent 817e3fcef1
commit e0605edb6e
6 changed files with 53 additions and 65 deletions
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32
deps/ox/src/ox/mc/write.hpp vendored
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@@ -111,9 +111,10 @@ Error MetalClawWriter::op(const char*, T *val, std::size_t len) {
if (len) {
// write the length
if (m_buffIt + sizeof(ArrayLength) < m_buffLen) {
*reinterpret_cast<LittleEndian<ArrayLength>*>(&m_buff[m_buffIt]) = static_cast<ArrayLength>(len);
m_buffIt += sizeof(ArrayLength);
const auto arrLen = mc::encodeInteger(len);
if (m_buffIt + arrLen.length < m_buffLen) {
ox_memcpy(&m_buff[m_buffIt], arrLen.data, arrLen.length);
m_buffIt += arrLen.length;
} else {
err = MC_BUFFENDED;
}
@@ -140,28 +141,11 @@ Error MetalClawWriter::appendInteger(I val) {
Error err = 0;
bool fieldSet = false;
if (val) {
if (m_buffIt + sizeof(I) < m_buffLen) {
LittleEndian<I> leVal = val;
// bits needed to represent number factoring in space possibly needed
// for signed bit
const auto bits = mc::highestBit(val) + (ox::is_signed<I> ? 1 : 0) / 8;
// bytes needed to store value
std::size_t bytes = bits / 8 + (bits % 8 != 0);
const auto bytesIndicator = onMask<uint8_t>(bytes - 1) << (7 - bytes);
// factor in bits needed for bytesIndicator (does not affect bytesIndicator)
// bits for integer + bits needed to represent bytes > bits available
if (bits + bytes > bytes * 8) {
++bytes;
}
if (bytes == 9) {
m_buff[m_buffIt++] = bytesIndicator;
} else {
}
*reinterpret_cast<LittleEndian<I>*>(&m_buff[m_buffIt]) = leVal;
auto mi = mc::encodeInteger(val);
if (mi.length < m_buffLen) {
fieldSet = true;
m_buffIt += sizeof(I);
ox_memcpy(&m_buff[m_buffIt], mi.data, mi.length);
m_buffIt += mi.length;
} else {
err |= MC_BUFFENDED;
}