private void writeFile(Operation operation) throws Exception {
Logger.logDebug("Start operation to send writeFile request to datanode", getClass());
// on a write request, the parameter is a FileWriteOperationParameter
FileWriteOperationParameter fileWriteParm =
(FileWriteOperationParameter) operation.getParamProto();
// find all datanodes that will be receiving that file
List<DatanodeInfo> datanodes = Datanodes.findDatanodesForFileWrite(fileWriteParm.getDfsFile());
Logger.logDebug(
"Operation will send write request to " + datanodes.size() + " datanodes: ", getClass());
// add the chosen datanodes to the operation parameter
for (DatanodeInfo datanodeInfo : datanodes) {
fileWriteParm.addDatanode(datanodeInfo);
Logger.logDebug(">>> " + datanodeInfo, getClass());
}
// remove valid datanodes from the dfsFile
FileStructure.getInstance()
.removeValidDatanodes(fileWriteParm.getFilePath(), fileWriteParm.getDfsFile().getName());
// send the request to the first datanode
FileOperationReqProtocol fileOperationRequest =
new FileOperationReqProtocolImpl(fileWriteParm.findNextDatanode(), operation);
fileOperationRequest.requestFileOperation();
}
private void readFile(Operation operation) throws Exception {
Logger.logDebug("Start operation to send readFile request to datanode", getClass());
// on a read request, the parameter is a FileReadOperationParameter
FileReadOperationParameter fileReadParm =
(FileReadOperationParameter) operation.getParamProto();
// find the datanode that will be sending that file
List<DatanodeInfo> datanodes = Datanodes.findDatanodesForFileWrite(fileReadParm.getDfsFile());
Logger.logDebug("Operation will send read request to one of the valid datanodes: ", getClass());
// add the chosen datanodes to the operation parameter
for (DatanodeInfo datanodeInfo : datanodes) {
fileReadParm.addDatanode(datanodeInfo);
Logger.logDebug(">>> " + datanodeInfo, getClass());
}
// TODO receive file from multiple datanodes, someday
// send the request to the first datanode
FileOperationReqProtocol fileOperationRequest =
new FileOperationReqProtocolImpl(fileReadParm.findNextDatanode(), operation);
fileOperationRequest.requestFileOperation();
}