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ID Datedown Author Topic Subject
  1170   18 Mar 2016 William PageBug Reportincomplete copy using odbedit copy
Hi,

Attempting to copy a subtree to a new location in the ODB using odbedit with "copy <src> <dest>" is 
occasionally not copying the entire <src> subtree.

I am experiencing this issue consistently when trying to copy subtrees from the "/Equipment" ODB tree to 
a new location.  The first 2-3 variables/directories of the <src> subtree will be copied to <dest> but the 
full subtree will not be copied over.
  1169   10 Mar 2016 Thomas LindnerInfoNew rootana forum | rootana web display tools
We have started a new elog for discussions of the ROOTANA MIDAS analyzer package
[1], which is used at TRIUMF and elsewhere for quick displays of MIDAS data. 
The forum is available here

https://midas.triumf.ca/elog/Rootana

I would note that we have recently finished implementing a system in rootana for
easy web displays of MIDAS data, using ROOT's THttpServer to post histograms. 
Details on this new scheme are here

https://midas.triumf.ca/elog/Rootana/1

and

https://midas.triumf.ca/MidasWiki/index.php/Rootana_javascript_displays

Please sign up for the forum if you are interested in getting ROOTANA-related
discussions.

Thomas

[1] https://midas.triumf.ca/MidasWiki/index.php/ROOTANA
  1168   09 Mar 2016 Konstantin OlchanskiInfo/Experiment/Edit on start/Edit Run number
The MIDAS documentation here:
  https://midas.triumf.ca/MidasWiki/index.php/Edit-on-start_Parameters
is missing informaiton about this ODB entry:
  /Experiment/Edit on start/Edit Run number (TID_BOOL)

This is what it does in mhttpd:
a) if it exists and is of type TID_BOOL and set to "n", run number is not editable
b) "Edit run number" itself is hidden, will not show up on the web page

This is what it does in odbedit:
a) it is hidden, will not show up in the list of run parameters
b) it's value has no effect, run number is always editable.

K.O.
  1167   02 Mar 2016 ZiyiGuoForumProblem with BLTRead
> > Dear all,
> >
> > I'm using MIDAS system and CAEN V1721 to digitize the waveform from photomultipliers (
> > and the link bridge to PC is V2718 ). I use BLTRead to read data of the digitizer, but
> > I found that if the event counting rate is high ( about 100KB/s ), the communication
> > of V1721 and PC would be suspended randomly, and I get an error code of -2. Could you
> > give me some suggestion? Thanks a lot.
>
> Hi,
>
> Can you provide the BLTread call fragment code and the PC /var/log/messages at the time of
> the hang up.
> What is needed to restart the daq?
>
> PAA

Hi Pierre-Andre,

Sorry for my late reply, because the data acquisition system now is running other experiment.
Here is my code. Is there something wrong? Thanks!




/* Read FADC data */
int NByteOfOneEvent = HeadSize + SampSize * NChannel;
int NDWordOfOneEvent = NByteOfOneEvent/4;


/* 1. Create FADC bank. One bank for one branch of a tree or one array branch with length. */
bk_create(pevent, "FADC", TID_DWORD, (void**)&pdata);

uint32_t size_remaining_dwords;
int dwords_read;

/* 2. Read out the event and assign them to pdata (bank buffer) */
//read size of event to be read
sCAEN = CAENComm_Read32(hFADC[card], V1721_EVENT_SIZE, &size_remaining_dwords);

if( size_remaining_dwords < NDWordOfOneEvent ) {
printf("\r\nSize of available data is less than the required size of one event.\r\n");
}

/* Read */
DWORD *pFadcData;
sCAEN = CAENComm_BLTRead(hFADC[card], V1721_EVENT_READOUT_BUFFER, pdata, NDWordOfOneEvent, &dwords_read);

// These code in "if" is for restart communication and save the time information if the communication was suspended

if(sCAEN != 0)
{
//printf("sCAEN =%d \n", sCAEN);
time_t t = time(0);
char tmp[64];
strftime(tmp,sizeof(tmp),"%Y/%m/%d %X %Z",localtime(&t));
fprintf(logfile,tmp);
fprintf(logfile,"\n Here met communication error \n");
printf(" Here met communication error \n");

//re-establish communication
sCAEN = CAENComm_CloseDevice(hFADC[card]);
fprintf(logfile,"sCAEN =%d, device closed **********\n", sCAEN);

ss_sleep(2000);

sCAEN = CAENComm_OpenDevice(CAENComm_PCIE_OpticalLink, l, d, FADCBA[card], &(hFADC[card]));

if (sCAEN == CAENComm_Success) {
fprintf(logfile,"re-establish communication, handle:%d, sCAEN=%d \n", hFADC[card], sCAEN);
}
else {
sCAEN = CAENComm_OpenDevice(CAENComm_PCIE_OpticalLink, l, d, FADCBA[card], &(hFADC[card]));
fprintf(logfile,"try open device again sCAEN= %d\n", sCAEN); }

//pause ongoing reading process
sCAEN = ov1721_AcqCtl(hFADC[card], V1721_RUN_STOP);
sCAEN = CAENComm_Read32(hFADC[card], V1721_EVENT_STORED, &eStored);

//discard FADC buffer
sCAEN = CAENComm_Write32(hFADC[card], V1721_SW_CLEAR, 0);
fprintf(logfile," number of %d events discarded \n\n", eStored);
sCAEN = ov1721_AcqCtl(hFADC[card], V1721_RUN_START);
}

//dwords_read: Number of the words that actually read from the device.
if( dwords_read != NDWordOfOneEvent ) {
printf("\r\nSize of data read out doesn't equal to the required size of one event. \r\n");
}

EvtCounterFadc[card] = *(pdata+2) & 0x00ffffff;

/* 3. Update bank pointer position */
pdata += dwords_read;

/* 4. Finish one bank */
bk_close(pevent, pdata);
  1166   26 Feb 2016 Konstantin OlchanskiSuggestionscript command limited to 256 characters; remove limit?
> Using low-level memory allocation routines in higher-level programs like mhttpd makes me nervous.

It should not, people have used malloc() for decades now without much injury to themselves. (Thomas corrects me: some people had big injury to their pride, me included).

> We could use vector arrays to allow variable-sized allocation, and use the data() member function to access the char* needed for functions like strlcat,
> db_get_data, and db_sprintf.

I thought auto_ptr was the correct tool to allocate "I just need a few bytes for a few minutes" arrays, but there is some discrepancy
between delete and delete[] (with brackets) and auto_ptr p(new char[i]) is verboten (even though it compiles just fine).

I ended up writing a custom replacement for auto_ptr called auto_string - now in mhttpd.cxx available for use in other places like this.

Still I think a db_get_data() that returns allocated memory is the correct solution. But this memory still needs to be released and lacking auto_ptr it opens the door for memory leaks.

> This conforms to the c++ standard, but doesn't require explicit freeing by the user - at least, not when you're allocating std::vector<char>

I do not think std::vector<char> can be cast into "char*" and used as replacement of "char str[100]" or "char* str = malloc(i);"

In other new, the limit on the command length is now removed.

K.O.

> 
> Amy
> 
> > Thank you for reporting this problem:
> > 
> > a) ODB key *names* are restricted to 31 characters (32 bytes, last byte is a NUL), not 256 characters.
> > b) ODB string length is unlimited (32-bit length field)
> > c) ODB C API "db_get_value" & co require fixed length buffer and most users of this API provide a 256-byte fixed buffer for strings, some of them also do not 
> > check the status code, resulting in silent truncation. (I think the ODB functions themselves report truncation to midas.log, so not completely silent).
> > 
> > We try to fix this where we must - but it is cumbersome with the current ODB API - as in your fix on has to:
> > - get the ODB key, extract size
> > - allocate buffer
> > - call db_get_value() & co
> > - use the data
> > - remember to free the buffer on each and every return path
> > 
> > The first three steps could become one if we had an ODB "get_data" function that automatically allocated the data buffer.
> > 
> > But the main source of bugs will be the last step - remember to free the buffer, always.
> > 
> > P.S.
> > 
> > We are not alone in pondering how to do this best. If you want to see it "done right",
> > read the fresh-off-the-presses book "Go Programming Language" by Alan Donovan and Brian Kernighan,
> > http://www.gopl.io/
> > 
> > Brian Kernighan is the "K" in K&R "C programming language", still around and kicking, now at Google.
> > Sadly the "R" passed away in 2011 - http://www.nytimes.com/2011/10/14/technology/dennis-ritchie-programming-trailblazer-dies-at-70.html
> > 
> > K.O.
> > 
> > > Both the /Script and /CustomScript trees in the ODB allow users to trigger a 
> > > script via Midas - which silently truncates command strings longer than 
> > > 256 characters.
> > > 
> > > I'd prefer that Midas place no limit on string length.  Failing that, it would be
> > > helpful to have character limits called out in the documentation 
> > > (https://midas.triumf.ca/MidasWiki/index.php//Script_ODB_tree#.3Cscript-name.3E_key_or_subtree,
> > > https://midas.triumf.ca/MidasWiki/index.php//Customscript_ODB_tree).
> > > 
> > > As far as I can tell, odb.c allows arbitrarily large strings in the ODB data.  
> > > (Although key *names* are restricted to 256 characters.)  I've submitted one 
> > > possible version of an arbitrary-length exec_script() as a pull request 
> > > (https://bitbucket.org/tmidas/midas/pull-requests/).
> > > 
> > > Am I misunderstanding any critical pieces?  Does Midas intentionally treat 
> > > strings in the ODB as limited to 256 characters?
  1165   23 Feb 2016 Pierre-Andre AmaudruzForumProblem with BLTRead
> Dear all,
> 
> I'm using MIDAS system and CAEN V1721 to digitize the waveform from photomultipliers ( 
> and the link bridge to PC is V2718 ). I use BLTRead to read data of the digitizer, but 
> I found that if the event counting rate is high ( about 100KB/s ), the communication 
> of V1721 and PC would be suspended randomly, and I get an error code of -2. Could you 
> give me some suggestion? Thanks a lot.

Hi, 

Can you provide the BLTread call fragment code and the PC /var/log/messages at the time of 
the hang up.
What is needed to restart the daq?

PAA
  1164   22 Feb 2016 ZiyiGuoForumProblem with BLTRead
Dear all,

I'm using MIDAS system and CAEN V1721 to digitize the waveform from photomultipliers ( 
and the link bridge to PC is V2718 ). I use BLTRead to read data of the digitizer, but 
I found that if the event counting rate is high ( about 100KB/s ), the communication 
of V1721 and PC would be suspended randomly, and I get an error code of -2. Could you 
give me some suggestion? Thanks a lot.
  1163   15 Feb 2016 Stefan RittSuggestionreducing sleep time in mhttpd main loop (for sequencer)
> Hmm, yeah, I'm not sure about how to handle reducing the wait time to zero after ODB set commands.
> 
> But it does seem like it would be straight-forward to increase the sleep time for waits; I'll look into
> a clean way of doing that.

Let's see how your 10 ms work in real life. If we need variable wait times, I can implement this for your without much effort.

Stefan
  1162   15 Feb 2016 Thomas LindnerSuggestionreducing sleep time in mhttpd main loop (for sequencer)
> > I checked how much extra CPU was used if the sleep was reduced from 100ms to
> > 20ms.  I found that when a sequence was not running the CPU increased from 0% to
> > 0.2% with my change.  When a sequence was running the CPU increased from 0.8% to
> > 4% with my change.  4% is a little high, though I'd say still reasonable.  I
> > found that most of the CPU usage was occuring because every call to
> > 'sequencer()' resulted in a call to db_set_record("/Sequencer/State"...).  I
> > guess that making that call 50 times causes the somewhat heavy CPU usage.
> > 
> > I would argue that it would still be worth making that change, so that the
> > sequencer can be more zippy.
> 
> The minimal time slice on most systems is 10 ms, and nothing prevents us from switching to
> that. The original 100 ms was more for the fact that you can see the sequencer statements
> executed one after the other (with the color bar). But this is more a "debugging" feature which 
> we not really need. 

OK, I made this change; sleep is now 10ms on main thread.  Seems to work fine on SL6 and MacOS.

> To do it "right" the sequencer would have to _return_ a sleep time. Like if it is in a wait loop (as
> most of the time), the sleep time could be close to 1 second, to correctly update the wait
> progress bar. If the sequencer executes ODB set statements, the wait time could be zero, so
> thousands of statements can be executed in one second. The problem we will then have of course
> that the sequencer will block the "request_mutex" almost always, which would prevent the
> mongoose server from serving anything. So this should be carefully tested. It could be (on most OS)
> that releasing the mutex by the main loop immediately switches to the mongoose thread, which would
> make the web server still quite responsive, but I'm not sure about that. So as a first change making
> the sleep time 10ms should be fine.

Hmm, yeah, I'm not sure about how to handle reducing the wait time to zero after ODB set commands.

But it does seem like it would be straight-forward to increase the sleep time for waits; I'll look into
a clean way of doing that.
  1161   06 Feb 2016 Stefan RittSuggestionreducing sleep time in mhttpd main loop (for sequencer)
> There were some complaints that the MIDAS sequencer was slow.  Specifically, the
> complaint was that even lines in the sequence that didn't do any (like COMMENT
> commands) tooks > 100ms to execute.  These slow sequencer steps could be a
> little annoying if a script had to change a large number of ODB variables before
> starting.
> 
> I tested this a little using a trivial sequence; note that I did all tests using
> mhttpd with mongoose enabled on a newer macbook pro.  I found that with the
> mongoose server each line in a sequencer script was taking ~100ms.  This is
> consistent with the loop in the main thread, which is only doing a cm_yield and
> a sleep:
> 
>    while (!_abort) {
>       status = ss_mutex_wait_for(request_mutex, 0);
>       status = cm_yield(0);
>       if (status == RPC_SHUTDOWN)
>          break;
>       sequencer();
>       status = ss_mutex_release(request_mutex);
>       ss_sleep(100);
>    }
> 
> I tested reducing the sleep to 20ms.  As expected, this made the sequencer more
> zippy, able to execute ~50 commands per second.
> 
> I tried to think what would be downsides to making this change.  I think that
> the main web communication should not be affected, because that communication is
> all handled by the separate mongoose thread.
> 
> I checked how much extra CPU was used if the sleep was reduced from 100ms to
> 20ms.  I found that when a sequence was not running the CPU increased from 0% to
> 0.2% with my change.  When a sequence was running the CPU increased from 0.8% to
> 4% with my change.  4% is a little high, though I'd say still reasonable.  I
> found that most of the CPU usage was occuring because every call to
> 'sequencer()' resulted in a call to db_set_record("/Sequencer/State"...).  I
> guess that making that call 50 times causes the somewhat heavy CPU usage.
> 
> I would argue that it would still be worth making that change, so that the
> sequencer can be more zippy.

The minimal time slice on most systems is 10 ms, and nothing prevents us from switching to
that. The original 100 ms was more for the fact that you can see the sequencer statements
executed one after the other (with the color bar). But this is more a "debugging" feature which 
we not really need. 

To do it "right" the sequencer would have to _return_ a sleep time. Like if it is in a wait loop (as
most of the time), the sleep time could be close to 1 second, to correctly update the wait
progress bar. If the sequencer executes ODB set statements, the wait time could be zero, so
thousands of statements can be executed in one second. The problem we will then have of course
that the sequencer will block the "request_mutex" almost always, which would prevent the
mongoose server from serving anything. So this should be carefully tested. It could be (on most OS)
that releasing the mutex by the main loop immediately switches to the mongoose thread, which would
make the web server still quite responsive, but I'm not sure about that. So as a first change making
the sleep time 10ms should be fine.

Stefan
  1160   05 Feb 2016 Thomas LindnerSuggestionreducing sleep time in mhttpd main loop (for sequencer)
> There were some complaints that the MIDAS sequencer was slow.  Specifically, the
> complaint was that even lines in the sequence that didn't do any (like COMMENT
> commands) tooks > 100ms to execute.  These slow sequencer steps could be a
> little annoying if a script had to change a large number of ODB variables before
> starting.
> ...
> I checked how much extra CPU was used if the sleep was reduced from 100ms to
> 20ms.  I found that when a sequence was not running the CPU increased from 0% to
> 0.2% with my change.  When a sequence was running the CPU increased from 0.8% to
> 4% with my change.  4% is a little high, though I'd say still reasonable.  I
> found that most of the CPU usage was occuring because every call to
> 'sequencer()' resulted in a call to db_set_record("/Sequencer/State"...).  I
> guess that making that call 50 times causes the somewhat heavy CPU usage.

One additional point: I think that it would be reasonably simple to reduce this CPU
usage even while a sequence was going on.  I would guess that for many sequences a
lot of time was spent in a 'WAIT SECONDS' command, since you would presumably want
to wait while data was being taken or conditions stabilizing.  I think that if you
are in a 'WAIT SECONDS' command that hasn't been satisfied then there probably isn't
any reason to do the db_set_record at the end of the sequencer() method.
  1159   05 Feb 2016 Thomas LindnerSuggestionreducing sleep time in mhttpd main loop (for sequencer)
There were some complaints that the MIDAS sequencer was slow.  Specifically, the
complaint was that even lines in the sequence that didn't do any (like COMMENT
commands) tooks > 100ms to execute.  These slow sequencer steps could be a
little annoying if a script had to change a large number of ODB variables before
starting.

I tested this a little using a trivial sequence; note that I did all tests using
mhttpd with mongoose enabled on a newer macbook pro.  I found that with the
mongoose server each line in a sequencer script was taking ~100ms.  This is
consistent with the loop in the main thread, which is only doing a cm_yield and
a sleep:

   while (!_abort) {
      status = ss_mutex_wait_for(request_mutex, 0);
      status = cm_yield(0);
      if (status == RPC_SHUTDOWN)
         break;
      sequencer();
      status = ss_mutex_release(request_mutex);
      ss_sleep(100);
   }

I tested reducing the sleep to 20ms.  As expected, this made the sequencer more
zippy, able to execute ~50 commands per second.

I tried to think what would be downsides to making this change.  I think that
the main web communication should not be affected, because that communication is
all handled by the separate mongoose thread.

I checked how much extra CPU was used if the sleep was reduced from 100ms to
20ms.  I found that when a sequence was not running the CPU increased from 0% to
0.2% with my change.  When a sequence was running the CPU increased from 0.8% to
4% with my change.  4% is a little high, though I'd say still reasonable.  I
found that most of the CPU usage was occuring because every call to
'sequencer()' resulted in a call to db_set_record("/Sequencer/State"...).  I
guess that making that call 50 times causes the somewhat heavy CPU usage.

I would argue that it would still be worth making that change, so that the
sequencer can be more zippy.
  1158   28 Jan 2016 Amy RobertsSuggestionscript command limited to 256 characters; remove limit?
Using low-level memory allocation routines in higher-level programs like mhttpd makes me nervous.

We could use vector arrays to allow variable-sized allocation, and use the data() member function to access the char* needed for functions like strlcat,
db_get_data, and db_sprintf.

This conforms to the c++ standard, but doesn't require explicit freeing by the user - at least, not when you're allocating std::vector<char>.

Amy

> Thank you for reporting this problem:
> 
> a) ODB key *names* are restricted to 31 characters (32 bytes, last byte is a NUL), not 256 characters.
> b) ODB string length is unlimited (32-bit length field)
> c) ODB C API "db_get_value" & co require fixed length buffer and most users of this API provide a 256-byte fixed buffer for strings, some of them also do not 
> check the status code, resulting in silent truncation. (I think the ODB functions themselves report truncation to midas.log, so not completely silent).
> 
> We try to fix this where we must - but it is cumbersome with the current ODB API - as in your fix on has to:
> - get the ODB key, extract size
> - allocate buffer
> - call db_get_value() & co
> - use the data
> - remember to free the buffer on each and every return path
> 
> The first three steps could become one if we had an ODB "get_data" function that automatically allocated the data buffer.
> 
> But the main source of bugs will be the last step - remember to free the buffer, always.
> 
> P.S.
> 
> We are not alone in pondering how to do this best. If you want to see it "done right",
> read the fresh-off-the-presses book "Go Programming Language" by Alan Donovan and Brian Kernighan,
> http://www.gopl.io/
> 
> Brian Kernighan is the "K" in K&R "C programming language", still around and kicking, now at Google.
> Sadly the "R" passed away in 2011 - http://www.nytimes.com/2011/10/14/technology/dennis-ritchie-programming-trailblazer-dies-at-70.html
> 
> K.O.
> 
> > Both the /Script and /CustomScript trees in the ODB allow users to trigger a 
> > script via Midas - which silently truncates command strings longer than 
> > 256 characters.
> > 
> > I'd prefer that Midas place no limit on string length.  Failing that, it would be
> > helpful to have character limits called out in the documentation 
> > (https://midas.triumf.ca/MidasWiki/index.php//Script_ODB_tree#.3Cscript-name.3E_key_or_subtree,
> > https://midas.triumf.ca/MidasWiki/index.php//Customscript_ODB_tree).
> > 
> > As far as I can tell, odb.c allows arbitrarily large strings in the ODB data.  
> > (Although key *names* are restricted to 256 characters.)  I've submitted one 
> > possible version of an arbitrary-length exec_script() as a pull request 
> > (https://bitbucket.org/tmidas/midas/pull-requests/).
> > 
> > Am I misunderstanding any critical pieces?  Does Midas intentionally treat 
> > strings in the ODB as limited to 256 characters?
  1157   28 Jan 2016 Konstantin OlchanskiSuggestionscript command limited to 256 characters; remove limit?
Thank you for reporting this problem:

a) ODB key *names* are restricted to 31 characters (32 bytes, last byte is a NUL), not 256 characters.
b) ODB string length is unlimited (32-bit length field)
c) ODB C API "db_get_value" & co require fixed length buffer and most users of this API provide a 256-byte fixed buffer for strings, some of them also do not 
check the status code, resulting in silent truncation. (I think the ODB functions themselves report truncation to midas.log, so not completely silent).

We try to fix this where we must - but it is cumbersome with the current ODB API - as in your fix on has to:
- get the ODB key, extract size
- allocate buffer
- call db_get_value() & co
- use the data
- remember to free the buffer on each and every return path

The first three steps could become one if we had an ODB "get_data" function that automatically allocated the data buffer.

But the main source of bugs will be the last step - remember to free the buffer, always.

P.S.

We are not alone in pondering how to do this best. If you want to see it "done right",
read the fresh-off-the-presses book "Go Programming Language" by Alan Donovan and Brian Kernighan,
http://www.gopl.io/

Brian Kernighan is the "K" in K&R "C programming language", still around and kicking, now at Google.
Sadly the "R" passed away in 2011 - http://www.nytimes.com/2011/10/14/technology/dennis-ritchie-programming-trailblazer-dies-at-70.html

K.O.

> Both the /Script and /CustomScript trees in the ODB allow users to trigger a 
> script via Midas - which silently truncates command strings longer than 
> 256 characters.
> 
> I'd prefer that Midas place no limit on string length.  Failing that, it would be
> helpful to have character limits called out in the documentation 
> (https://midas.triumf.ca/MidasWiki/index.php//Script_ODB_tree#.3Cscript-name.3E_key_or_subtree,
> https://midas.triumf.ca/MidasWiki/index.php//Customscript_ODB_tree).
> 
> As far as I can tell, odb.c allows arbitrarily large strings in the ODB data.  
> (Although key *names* are restricted to 256 characters.)  I've submitted one 
> possible version of an arbitrary-length exec_script() as a pull request 
> (https://bitbucket.org/tmidas/midas/pull-requests/).
> 
> Am I misunderstanding any critical pieces?  Does Midas intentionally treat 
> strings in the ODB as limited to 256 characters?
  1156   28 Jan 2016 Konstantin OlchanskiReleaseFinal MIDAS JSON-RPC API
> > The final bits of the JSON-RPC API to MIDAS are committed.

JSON-RPC methods are now provided for all old ODBxxx() javascript functions, except ODBGetMsg().

The currently present RPC methods are sufficient to write the MIDAS "programs" and "alarms" pages
purely in HTML+Javascript (see the git branch feature/mhttpd_js). These pages can be served i.e. by apache httpd
with midas mhttpd only required to service the RPC requests.

Please see .../examples/javascript1/example.html on how to use the new RPC methods.

K.O.

P.S. Note how many examples use the generic mjsonrpc_call() because I did not write the corresponding
javascript functions - I wore out the cut-and-paste button on my keyboard. All are welcome to contribute
the missing functions, post them here or email them to me, I will commit them to midas git.
  1155   19 Jan 2016 Tom StuttardSuggestion64 bit bank type
> > I've seen that a similar question has been asked in 2011 but I'll ask again in 
> > case there are any updates. Is there any way to write 64-bit data words to MIDAS 
> > banks (other than breaking them up in to two 32-bit words, such as 2 DWORDs) 
> > currently? And if not, is there any plan to introduce this feature in the future?
> 
> There is no "breaking them up" as such, you can treat a midas bank as a char* array
> and store arbitrary data inside. In this sense, "there is no need" for a special 64-bit bank type.
> 
> For endian-ness conversion (if such things still matter, big-endian PPC CPUs still exist), single 64-bit 
> word converts the same as two 32-bit words, so here also "there is no need", once can use banks of 
> DWORD with equal effect.
> 
> The above applies equally to 64-bit integers and 64-bit double-precision IEEE-754 floating point 
> numbers.
> 
> But specifically for 64-bit values, such as float64, there is a big gotcha.
> 
> The MIDAS banks structure goes to great lengths to make sure each data type is correctly aligned,
> and gets it exactly wrong for 64-bit quantities - all because the bank header is three 32-bit words.
> 
> bankhheader1
> bh2
> bh3
> bankdata1 <--- misaligned
> ...
> bankdataN
> bh1
> bh2
> bh3
> banddata1 <--- aligned
> ... etc
> 
> So we could introduce QWORD banks today, but inside the midas file, they will be misaligned defeating 
> the only purpose of adding them.
> 
> I guess the misalignement could be cured by adding dummy words, dummy banks, dummy bank 
> headers, etc.
> 
> I figure this problem dates all the way bank where alignement to 16-bits was just getting important. 
> Today, in the VME word, I have to align things on 128-bit boundaries (for 2eSST 2x2 DWORD transfers).
> 
> So back to your question, what advantage do you see in using a QWORD bank instead of putting the 
> same data in a DWORD bank?
> 
> K.O.


Thanks very much for your reply. I have implemented your suggestion of treating the 64-bit array as a 32-bit 
array for the bank write/read and this solution is working for me.

Thanks again for your help.
  Draft   15 Jan 2016 Tom StuttardSuggestion64 bit bank type
> > I've seen that a similar question has been asked in 2011 but I'll ask again in 
> > case there are any updates. Is there any way to write 64-bit data words to MIDAS 
> > banks (other than breaking them up in to two 32-bit words, such as 2 DWORDs) 
> > currently? And if not, is there any plan to introduce this feature in the future?
> 
> There is no "breaking them up" as such, you can treat a midas bank as a char* array
> and store arbitrary data inside. In this sense, "there is no need" for a special 64-bit bank type.
> 
> For endian-ness conversion (if such things still matter, big-endian PPC CPUs still exist), single 64-bit 
> word converts the same as two 32-bit words, so here also "there is no need", once can use banks of 
> DWORD with equal effect.
> 
> The above applies equally to 64-bit integers and 64-bit double-precision IEEE-754 floating point 
> numbers.
> 
> But specifically for 64-bit values, such as float64, there is a big gotcha.
> 
> The MIDAS banks structure goes to great lengths to make sure each data type is correctly aligned,
> and gets it exactly wrong for 64-bit quantities - all because the bank header is three 32-bit words.
> 
> bankhheader1
> bh2
> bh3
> bankdata1 <--- misaligned
> ...
> bankdataN
> bh1
> bh2
> bh3
> banddata1 <--- aligned
> ... etc
> 
> So we could introduce QWORD banks today, but inside the midas file, they will be misaligned defeating 
> the only purpose of adding them.
> 
> I guess the misalignement could be cured by adding dummy words, dummy banks, dummy bank 
> headers, etc.
> 
> I figure this problem dates all the way bank where alignement to 16-bits was just getting important. 
> Today, in the VME word, I have to align things on 128-bit boundaries (for 2eSST 2x2 DWORD transfers).
> 
> So back to your question, what advantage do you see in using a QWORD bank instead of putting the 
> same data in a DWORD bank?
> 
> K.O.
  1153   05 Jan 2016 Konstantin OlchanskiSuggestion64 bit bank type
> I've seen that a similar question has been asked in 2011 but I'll ask again in 
> case there are any updates. Is there any way to write 64-bit data words to MIDAS 
> banks (other than breaking them up in to two 32-bit words, such as 2 DWORDs) 
> currently? And if not, is there any plan to introduce this feature in the future?

There is no "breaking them up" as such, you can treat a midas bank as a char* array
and store arbitrary data inside. In this sense, "there is no need" for a special 64-bit bank type.

For endian-ness conversion (if such things still matter, big-endian PPC CPUs still exist), single 64-bit 
word converts the same as two 32-bit words, so here also "there is no need", once can use banks of 
DWORD with equal effect.

The above applies equally to 64-bit integers and 64-bit double-precision IEEE-754 floating point 
numbers.

But specifically for 64-bit values, such as float64, there is a big gotcha.

The MIDAS banks structure goes to great lengths to make sure each data type is correctly aligned,
and gets it exactly wrong for 64-bit quantities - all because the bank header is three 32-bit words.

bankhheader1
bh2
bh3
bankdata1 <--- misaligned
...
bankdataN
bh1
bh2
bh3
banddata1 <--- aligned
... etc

So we could introduce QWORD banks today, but inside the midas file, they will be misaligned defeating 
the only purpose of adding them.

I guess the misalignement could be cured by adding dummy words, dummy banks, dummy bank 
headers, etc.

I figure this problem dates all the way bank where alignement to 16-bits was just getting important. 
Today, in the VME word, I have to align things on 128-bit boundaries (for 2eSST 2x2 DWORD transfers).

So back to your question, what advantage do you see in using a QWORD bank instead of putting the 
same data in a DWORD bank?

K.O.
  1152   05 Jan 2016 Tom StuttardSuggestion64 bit bank type
I've seen that a similar question has been asked in 2011 but I'll ask again in 
case there are any updates. Is there any way to write 64-bit data words to MIDAS 
banks (other than breaking them up in to two 32-bit words, such as 2 DWORDs) 
currently? And if not, is there any plan to introduce this feature in the future?

Many thanks,
Tom
  1151   10 Dec 2015 Stefan RittInfoSmall change in loading .odb files
A small change in loading .odb files has been implemented. When you load an array from a .odb file, the indices in each line were not evaluated, only the complete array was loaded. In our experiment we need however to load only a few values, like some HV values for some channels but leaving the other values as they are. I changed slightly the code of db_paste() to correctly evaluate the index in each line of the .odb file. This way one can write for example following .odb file:

[/Equipment/HV/Variables]
Demand = FLOAT[256] :
[10] 100.1
[11] 100.2
[12] 100.3
[13] 100.4
[14] 100.5
[15] 100.6

then load it in odbedit via the "load" command, and then only change channels 10-15.

Stefan
ELOG V3.1.4-2e1708b5