MojErr MojDbIdGenerator::id(MojObject& idOut)
{
// an id consists of a timestamp (in microsecs) concatenated with a 32-bit random number.
// The goal is to have a very low likelihood of id collision among multiple devices owned
// by the same user (so they can can share an id-space) while still keeping them sequential
// to minimize db fragmentation.
MojThreadGuard guard(m_mutex);
MojUInt32 randNum;
MojErr err = MojRandom(&m_randBuf, &randNum);
MojErrCheck(err);
guard.unlock();
MojTime time;
err = MojGetCurrentTime(time);
MojErrCheck(err);
MojBuffer buf;
MojDataWriter writer(buf);
err = writer.writeInt64(time.microsecs());
MojErrCheck(err);
err = writer.writeUInt32(randNum);
MojErrCheck(err);
MojVector<MojByte> byteVec;
err = buf.toByteVec(byteVec);
MojErrCheck(err);
MojString str;
err = str.base64Encode(byteVec, false);
MojErrCheck(err);
idOut = str;
return MojErrNone;
}
MojErr MojDbQuery::Page::toObject(MojObject& objOut) const
{
MojString str;
MojErr err = str.base64Encode(m_key.byteVec(), false);
MojErrCheck(err);
objOut = str;
return MojErrNone;
}
