IReader* CBDB_BLobFile::CreateReader()
{
EBDB_ErrCode ret = Fetch();
DBT* dbt = CloneDBT_Key();
// lob exists, we can read it now (or write)
if (ret == eBDB_Ok) {
return new CBDB_BlobReaderWriter(m_DB, dbt, LobSize(), GetTxn());
}
return 0;
}
CBDB_BLobStream* CBDB_BLobFile::CreateStream()
{
EBDB_ErrCode ret = Fetch();
DBT* dbt = CloneDBT_Key();
// lob exists, we can read it now (or write)
if (ret == eBDB_Ok) {
return new CBDB_BLobStream(m_DB, dbt, LobSize(), GetTxn());
}
// no lob yet (write stream)
return new CBDB_BLobStream(m_DB, dbt, 0, GetTxn());
}
EBDB_ErrCode
CBDB_BLobFile::ReadRealloc(TBuffer& buffer)
{
EBDB_ErrCode ret;
// use the maximum capacity
size_t capacity = buffer.capacity();
if (capacity > buffer.size()) {
buffer.resize_mem(capacity);
}
if (buffer.size() == 0) {
buffer.resize_mem(10);
}
while(1) {
try {
void* p = &buffer[0];
ret = Fetch(&p, buffer.size(), eReallocForbidden);
if (ret != eBDB_Ok) {
buffer.resize_mem(0);
return ret;
}
buffer.resize(LobSize());
}
catch (CBDB_ErrnoException& ex) {
// check if we have insufficient buffer
if (ex.IsBufferSmall() || ex.IsNoMem()) {
// increase the buffer and re-read
buffer.resize_mem(LobSize());
} else {
throw;
}
continue;
}
break;
} // while
return ret;
}
/// Get LOB size. Becomes available right after successfull Fetch.
size_t BlobSize() const { return LobSize(); }
