I now fully understand the MIDAS RPC code, had to add some debugging printfs, 
write some test code (odbedit test_rpc), catch and fix a few bugs.

Fixes for the bugs are now committed.

Small refactor of rpc_execute() should be committed soon, this removes the 
"goto" in the memory allocation of output buffer. Stefan's original code used a 
fixed size buffer, I later added allocation "as-neeed" but did not fully 
understand everything and implemented it as "if buffer too small, make it 
bigger, goto start over again".

After that, I can implement support for std::string and std::vector<char>.

The way it looks right now, the on-the-wire data format is flexible enough to 
make this change backward-compatible and allow MIDAS programs built with old 
MIDAS to continue connecting to the new MIDAS and vice-versa.

MIDAS RPC support for std::string should let us improve security by removing 
even more uses of fixed-size string buffers.

Support for std::vector<char> will allow removal of last places where 
MAX_EVENT_SIZE is used and simplify memory allocation in other "give me data" 
RPC calls, like RPC_JRPC and RPC_BRPC.

K.O.

root_v6.30.06.Linux-ubuntu22.04-x86_64-gcc11.4 the libtbb-dev package.

This is a new requirement and it is not listed in the ROOT dependancies page (I left a note on the ROOT forum, hopefully it will be 
fixed quickly). https://root.cern/install/dependencies/

Symptom is when starting ROOT, you get an error:
cling::DynamicLibraryManager::loadLibrary(): libtbb.so.12: cannot open shared object file: No such file or directory
and things do not work.

Fix is to:
apt install libtbb-dev

K.O.

Ubuntu 22 has almost everything necessary to cross-build arm64 MIDAS frontends:

# apt install g++-12-aarch64-linux-gnu gcc-12-aarch64-linux-gnu-base libstdc++-12-dev-arm64-cross
$ aarch64-linux-gnu-gcc-12 -o ttcp.aarch64 ttcp.c -static

to cross-build MIDAS:

make arm64_remoteonly -j

run programs from $MIDASSYS/linux-arm64-remoteonly/bin
link frontends to libraries in $MIDASSYS/linux-arm64-remoteonly/lib

Ubuntu 22 do not provide an arm64 libz.a, as a workaround, I build a fake one. (we do not have HAVE_ZLIB anymore...). or you 
can link to libz.a from your arm64 linux image, assuming include/zlib.h are compatible.

K.O.

This is moving slowly. I now have RPC caller side support for std::string and 
std::vector<char>. RPC server side is next. K.O.

> MIDAS RPC data format.
> 3) RPC reply
> 3.1) header:
> 3.2) followed by data for RPC_OUT parameters:
> 
> data sizes and encodings are the same as for RPC_IN parameters.

Correction:

RPC_VARARRAY data encoding for data returned by RPC is different from data sent to RPC:

4 bytes of arg_size (before 8-byte alignement), (for data sent to RPC, it's 4 bytes of param_size, after 8-byte alignment)
4 bytes of padding
param_size of data

K.O.

P.S. bug/discrepancy caught by GCC/LLVM address sanitizer.

We are considering to remove the analyzer framework mana.cxx from MIDAS. It 
currently has some compiler warnings and we wonder if we should fix them which 
would take some time or just remove the file. We have now to much more modern 
analyzer frameworks "manalyzer" and "ROOTANA" which should be used instead.

Is anybody still using the mana.cxx framework?

/Stefan

Ok, no relevant complains so far, so I removed mana and rmana from the CMake build 
process, but left the file mana.cxx still in the repository for educational 
purposes ;-)

Stefan

I had two free afternoon and took the opportunity to write a new API for the MSCB 
system. I'm not sure if anybody else actually uses MSCB (MIDAS slow control bus), 
but anyhow. 

The new API is contained in a single header file mscbxx.h, and it's extremely 
simple to use. Here is some example code:

#include "mscbxx.h"

...
   // connect to node 10 at submaster mscb123
   midas::mscb m("mscb123", 10);

   // print node info and all variables
   std::cout << m << std::endl;

   // refresh all variables (read from MSCB device)
   m.read_range();
   
   // access individual variables
   float f = m[5];   // index access
   f = m["In0"];     // name access

   // write value to MSCB device
   m["In0"] = 1.234;
...


Any feedback is welcome.

Stefan

> Here is some example code:
> 
> #include "mscbxx.h"
>    f = m["In0"];     // name access
>    m["In0"] = 1.234;
> Any feedback is welcome.

Where is the example of error handling?

K.O.

Look at the C++ implementation of the MIDAS data file reader, the code is very 
simple to follow.

Depending on how old are your data files, you may run into a problem with 
misaligned 32-bit data banks. Latest MIDAS creates BANK32A events where all 
banks are aligned to 64 bits. old BANK32 format had banks alternating between 
aligned and misaligned. old 16-bit BANK format data hopefully you do not have.

If you successfully make a data format description file for MIDAS, please post 
it here for the next user.

K.O.



[quote="Adrian Fisher"]Hi! I'm working on creating a ksy file to help with 
parsing some data, but I'm having trouble finding some information. Right now, I 
have it set up very rudimentary - it grabs the event header and then uses the 
data bank size to grab the size of the data, but then I'm needing additional 
padding after the data bank to reach the next event.
However, there's some irregularity in the "padding" between data banks that I 
haven't been able to find any documentation for. For some reason, after the data 
banks, there's sections of data of either 168 or 192 bytes, and it's seemingly 
arbitrary which size is used. 
I'm just wondering if anyone has any information about this so that I'd be able 
to make some more progress in parsing the data.
The data I'm working with can be found at https://github.com/det-
lab/dataReaderWriter/blob/master/data/07180808_1735_F0001.mid.gz
And the ksy file that I've created so far is at https://github.com/det-
lab/dataReaderWriter/blob/master/kaitai/ksy/scdms_v1.ksy

There's also a block of data after the odb that runs for 384 bytes that I'm 
unsure the purpose of, if anyone could point me to some information about that.

Thank you![/quote]

> Ok, no relevant complains so far, so I removed mana and rmana from the CMake build 
> process, but left the file mana.cxx still in the repository for educational 
> purposes ;-)

+1

K.O.

> Where is the example of error handling?

#include "mscbxx.h"
#include "mexcept.h"

...
   try {
   
      // connect to node 10 at submaster mscb123
      midas::mscb m("mscb123", 10);

      // print a variable
      std::cout << m["Input0"] << std::endl;
   
   } catch (mexception e) {
      std::cout << e << std::endl; // simply print exception
   }
...

A new sequencer command "ODBLOOKUP" has been implemented, which does a lookup of a string in a string 
array in the ODB given by a path and returns its index as a number. If we have for example an array

/Examples/Names
   [0] Hello
   [1] Test
   [2] Other

and do a
 
ODBLOOKUP "/Examples/Names", "Test", index

we get a index equal 1.


/Stefan

> A new sequencer command "ODBLOOKUP" has been implemented, which does a lookup of a string in a string 
> array in the ODB given by a path and returns its index as a number. If we have for example an array
> 
> /Examples/Names
>    [0] Hello
>    [1] Test
>    [2] Other
> 
> and do a
>  
> ODBLOOKUP "/Examples/Names", "Test", index
> 
> we get a index equal 1.
> 

"value not found" sets "index" to ?
"odb key not found" sets "index" to ?
link to documentation?

K.O.

> "value not found" sets "index" to ?

It sets it actually to "not found". Since all variables are stings in the sequencer, you can then do a test like

ODBLOOKUP ..., index
if ($index == "not found")
  ...


> "odb key not found" sets "index" to ?

If the odb key is not found, the sequencer aborts.

> link to documentation?

The documentation is where it always has been: 

https://daq00.triumf.ca/MidasWiki/index.php/Sequencer#Sequencer_Commands

/Stefan

Hello, 

This is the error message I got:

[RP Streaming Frontend,ERROR] [midas.cxx:17806:cm_write_event_to_odb,ERROR] 
cannot create key for bank "DATA" with tid 24 in ODB, db_create_key() status 309
read_periodic_event: No data in ring buffer or error occurred

[RP Streaming Frontend,ERROR] [odb.cxx:3373:db_create_key,ERROR] invalid key type 
24 to create 'DATA' in '/Equipment/Periodic/Variables'

[RP Streaming Frontend,ERROR] [midas.cxx:17806:cm_write_event_to_odb,ERROR] 
cannot create key for bank "DATA" with tid 24 in ODB, db_create_key() status 309



I just need more information on what the error message means. Which data type 
refers to tid 24 and what does status 309 indicate?? 

There is definitely data in the ring buffer but I keep on getting this error.

Thank you!

M.G 

> [RP Streaming Frontend,ERROR] [midas.cxx:17806:cm_write_event_to_odb,ERROR] 
> cannot create key for bank "DATA" with tid 24 in ODB, db_create_key() status 309
> 
> 
> 
> I just need more information on what the error message means. Which data type 
> refers to tid 24 and what does status 309 indicate?? 

A tid (type identification) of 24 does actually not exist. See midas.h:327, so this tells
me that your bank header got corrupted. Somewhere you write over your data.

Stefan