bool RemoteDataSource::getARow(MemoryBuffer & out, RowCache & cache, byte cmd, __int64 row)
{
RowLocation location;
if (cache.getCacheRow(row, location))
{
out.append(location.matchLength, location.matchRow);
return true;
}
CMessageBuffer msg;
msg.setEndian(__BIG_ENDIAN);
msg.append(cmd);
msg.append(id);
msg.append(row);
sendReceive(msg);
bool ok;
msg.read(ok);
if (!ok) return false;
__int64 start;
msg.read(start);
VariableRowBlock * next = new VariableRowBlock(msg, start);
cache.addRowsOwn(next);
if (!cache.getCacheRow(row, location))
assertex(!"Internal Error!");
out.append(location.matchLength, location.matchRow);
return true;
}
IFvDataSource * createRemoteFileDataSource(const SocketEndpoint & server, const char * username, const char * password, const char * logicalName)
{
Owned<INode> serverNode = createINode(server);
CMessageBuffer msg;
msg.setEndian(__BIG_ENDIAN);
msg.append((byte)FVCMDcreatefile);
msg.append(myProcessSession());
msg.append(username);
msg.append(password);
msg.append(logicalName);
sendReceive(serverNode, msg);
unsigned short version;
unique_id_t id;
__int64 numRows;
bool isIndex;
msg.read(version);
msg.read(id);
msg.read(numRows);
Owned<IFvDataSourceMetaData> meta = deserializeDataSourceMeta(msg);
msg.read(isIndex);
if (id)
return new RemoteDataSource(server, id, meta, numRows, isIndex);
return 0;
}
void RemoteDataSource::beforeDispose()
{
CMessageBuffer msg;
msg.setEndian(__BIG_ENDIAN);
msg.append((byte)FVCMDdestroy);
msg.append(id);
sendReceive(msg);
}
static void sendReceive(INode * serverNode, CMessageBuffer & msg)
{
if (!queryWorldCommunicator().sendRecv(msg, serverNode, MPTAG_FILEVIEW, TIMEOUT))
throwError(FVERR_TimeoutRemoteFileView);
msg.setEndian(__BIG_ENDIAN);
IException * error = deserializeException(msg);
if (error)
throw error;
}
__int64 RemoteDataSource::numRows(bool force)
{
if (!force)
return cachedNumRows;
CMessageBuffer msg;
msg.setEndian(__BIG_ENDIAN);
msg.append((byte)FVCMDnumrows);
msg.append(id);
sendReceive(msg);
__int64 result;
msg.read(result);
return result;
}
bool RemoteDataSource::fetchRawRow(MemoryBuffer & out, __int64 offset)
{
CMessageBuffer msg;
msg.setEndian(__BIG_ENDIAN);
msg.append(FVCMDfetchraw);
msg.append(id);
msg.append(offset);
sendReceive(msg);
bool ok;
msg.read(ok);
if (!ok) return false;
size32_t len;
msg.read(len);
out.append(len, msg.readDirect(len));
return true;
}
