////// //---------------------------------------------------------------------------
////// // читает блок из потока каталога stream_from, собирая его по страницам
////// TStream* read_block(TStream* stream_from, int start, TStream* stream_to = nullptr)
////// {
////// stBlockHeader block_header;
//////
////// if (!stream_to)
////// {
////// stream_to = new TMemoryStream;
////// }
//////
////// stream_to->Seek(0, soFromBeginning);
////// stream_to->SetSize(0);
//////
////// if (start < 0
////// || start == LAST_BLOCK
////// || start > stream_from->GetSize())
////// {
////// return stream_to;
////// }
//////
////// stream_from->Seek(start, soFromBeginning);
////// stream_from->Read(&block_header, stBlockHeader::size());
//////
////// int32_t len = block_header.get_data_size();
//////
////// if (len == 0)
////// {
////// return stream_to;
////// }
//////
////// int32_t curlen = block_header.get_page_size();
////// start = block_header.get_next_page_addr();
//////
////// int32_t readlen = std::min(len, curlen);
////// stream_to->CopyFrom(stream_from, readlen);
//////
////// int32_t pos = readlen;
//////
////// while (start != LAST_BLOCK)
////// {
////// stream_from->Seek(start, soFromBeginning);
////// stream_from->Read(&block_header, block_header.size());
//////
////// curlen = block_header.get_page_size();
//////
////// start = block_header.get_next_page_addr();
//////
////// readlen = std::min(len - pos, curlen);
////// stream_to->CopyFrom(stream_from, readlen);
////// pos += readlen;
////// }
//////
////// return stream_to;
//////
////// }
#endregion
// читает блок из потока каталога stream_from, собирая его по страницам
public static Stream Read_Block(Stream stream_from, int start, ref int rlen, Stream stream_to = null)
{
//char temp_buf[32]; - оригинал
byte[] temp_buf = new byte[32];
stBlockHeader block_header = new stBlockHeader();
int len, curlen, pos, readlen;
if (stream_to == null)
{
stream_to = new MemoryStream();
}
stream_to.Seek(0, SeekOrigin.Begin);
stream_to.SetLength(0);
if (start < 0 || start == 0x7fffffff || start > stream_from.Length)
{
return(stream_to);
}
// спозиционироваться надо на start
stream_from.Seek(start, SeekOrigin.Begin);
block_header = ReadBlockHeaderFromData(stream_from);
len = block_header.get_data_size();
if (len == 0)
{
return(stream_to);
}
curlen = block_header.get_page_size();
start = block_header.get_next_page_addr();
readlen = Math.Min(len, curlen);
byte[] tmp_buf = new byte[readlen];
//((MemoryStream)stream_to).Capacity = readlen;
rlen = readlen;
stream_from.CopyTo(stream_to, readlen);
pos = readlen;
while (start != 0x7fffffff)
{
stream_from.Seek(start, SeekOrigin.Begin);
block_header = ReadBlockHeaderFromData(stream_from);
curlen = block_header.get_page_size();
start = block_header.get_next_page_addr();
readlen = Math.Min(len - pos, curlen);
if (readlen != 0)
{
stream_from.CopyTo(stream_to, readlen);
}
pos += readlen;
}
return(stream_to);
}
