Executable:

o2-dpl-raw-proxy

A proxy workflow to connect to a channel from DataDistribution. The incoming data is supposed to follow the O2 data model with header-payload pair messages. The header message must contain DataHeader and the internal DPL DataProcessingHeader. Only data which match the configured outputs will be forwarded.

Since payload can be split into several messages, the proxy will create a new message to merge all parts belonging to one payload entity.

o2-dpl-raw-proxy --dataspec "0:FLP/RAWDATA" --channel-config "name=readout-proxy,type=pair,method=bind,address=ipc:///tmp/stf-builder-dpl-pipe-0,transport=shmem,rateLogging=1"

Options:

  --dataspec arg (=A:FLP/RAWDATA;B:FLP/DISTSUBTIMEFRAME/0)
                                        selection string for the data to be 
                                        proxied
  --throwOnUnmatched                    throw if unmatched input data is found

Data is selected by using a configuration string of the format tag1:origin/description/subspec;tag2:..., the tags are arbitrary and only for internal reasons and are ignored. Example:

--dataspec 'A:FLP/RAWDATA;B:FLP/DISTSUBTIMEFRAME/0'

The input channel has name readout-proxy and is configured with option --channel-config.

By default, data blocks not matching the configured filter/output spec will be silently ignored. Use --throwOnUnmatched to apply a strict checking in order to indicate unmatched data.

The proxy workflow only defines the proxy process, workflows can be combined by piping them together om the command line

o2-dpl-raw-proxy --dataspec "0:FLP/RAWDATA" --channel-config "..." | the-subscribing-workflow

• stress test with data not following the O2 data model
• forwarding of shared memory messages
• vector handling of split payload parts in DPL
• make the channel config more convenient, do not require the full string and use defaults, e.g. for the name (which can not be changed anyhow)
• check if the channel config string can be parsed omitting tags, right now this is only possible for the first entry

Class RawParser implements a parser for O2 raw data which is organized in pages of a fixed size, each page starts with the RAWDataHeader. The page size may actually be smaller than the maximum size, depending on the header fields.

The parser class works on a contiguous sequence of raw pages in a raw buffer. Multiple versions of RAWDataHeader are supported transparently and selected depending on the version field of the header.

// option 1: parse method
RawParser parser(buffer, size);
auto processor = [&count](auto data, size_t length) {
  std::cout << "Processing block of length " << length << std::endl;
};
parser.parse(processor);

// option 2: iterator
RawParser parser(buffer, size);
for (auto it = parser.begin(), end = parser.end(); it != end; ++it, ++count) {
  std::cout << "Iterating block of length " << it.length() << std::endl;
  auto dataptr = it.data();
}

Executable:

o2-dpl-raw-parser

Parser workflow defines one process with configurable inputs and a loop over the input data which sets up the RawParser class and executes some basic parsing and statistic printout.

o2-dpl-raw-parser --input-spec "A:FLP/RAWDATA"

Options:

  --input-spec arg (=A:FLP/RAWDATA)

The workflow can be connected to the o2-dpl-raw-proxy workflow using pipe on command line.

documentation to be filled