// When performing a read, if we have an active batch we need to check it first
// before reading from the database, as the rest of the code assumes that once
// a database transaction begins reads are consistent with it. It would be good
// to change that assumption in future and avoid the performance hit, though in
// practice it does not appear to be large.
bool CTxDB::ScanBatch(const CDataStream &key, string *value, bool *deleted) const {
assert(activeBatch);
*deleted = false;
CBatchScanner scanner;
scanner.needle = key.str();
scanner.deleted = deleted;
scanner.foundValue = value;
leveldb::Status status = activeBatch->Iterate(&scanner);
if (!status.ok()) {
throw runtime_error(status.ToString());
}
return scanner.foundEntry;
}
bool RichListDB::ScanBatch(const CDataStream& key, std::string* value, bool* deleted) const
{
if (!activeBatch)
return false;
*deleted = false;
RichListDbBatchScanner scanner;
scanner.needle = key.str();
scanner.deleted = deleted;
scanner.foundValue = value;
leveldb::Status s = activeBatch->Iterate(&scanner);
if (!s.ok())
{
LogPrintf("RichListDB ScanBatch error: %s", s.ToString().c_str());
return false;
};
return scanner.foundEntry;
}
