There is an obvious "unwanted feature" in this version of the mhttpd. It writes the
"plot time" into the gif (mhttpd, if-statement starting in line 8853). 

Please check this obvious things more carefully in the future before submitting code. ;-)

> mhttpd and mlogger have been updated with potentially troublesome changes.
> Before using these latest versions, please make a backup of your ODB. This is
> svn revisions 4434 (mhttpd.c) and 4435 (mlogger.c).
> 
> These new features are now available:
> - a "feature complete" implementation of "history in an SQL database". We use
> this new code to write history data from the T2K test setup in the TRIUMF M11
> beam line to a MySQL database (mlogger) and to make history plots directly from
> this database (mhttpd). We still write normal midas history files and we have a
> utility to import midas .hst files into an SQL database (utils/mh2sql). The code
> is functional, but incomplete. For best SQL database data layout, you should
> enable the "per variable history" (but backup your ODB before you do this!). All
> are welcome to try it, kick the tires, report any problems. Documentation TBW.
> - experimental implementation of "ODBRpc" added to the midas javascript library
> (ODBSet, ODBGet & co). This permits buttons on midas "custom" web pages to
> invoke RPC calls directly into user frontend programs, for example to turn
> things on or off. Documentation TBW.
> - the mlogger/mhttpd implementation of /History/Tags has proved troublesome and
> we are moving away from it. The SQL database history implementation already does
> not use it. During the present transition period:
> - mlogger and mhttpd will now work without /History/Tags. This implementation
> reads history tags directly from the history files themselves. Two downsides to
> this: it is slower and tags become non-persistent: if some frontends have not
> been running for a while, their variables may vanish from the history panel
> editor. To run in this mode, set "/History/DisableTags" to "y". Existing
> /History/Tags will be automatically deleted.
> - for the above 2 reasons, I still recommend using /History/Tags, but the format
> of the tags is now changed to simplify management and reduce odb size. mlogger
> will automatically convert the tags to this new format (this is why you should
> make a backup of your ODB).
> - using old mlogger with new mhttpd is okey: new mhttpd understands both formats
> of /History/Tags.
> - using old mhttpd with new mlogger is okey: please set ODB
> "/History/CreateOldTags" to "y" (type TID_BOOL/"boolean") before starting mlogger.
> 
> K.O.

I have the following problems after updating to midas SVN 4936: the history 
system (web-page via mhttpd) seems to stop working. I checked the history files 
themself and they are indeed written, except that the events ID's are not the 
same anymore (I mean the ones defined under /Equipment/XXX/Common/Event ID), 
rather the mlogger seems to choose an ID by itself.
Currently the only way to get things working again was to recompile midas with 
adding -DOLD_HISTORY to the CFLAGS which is troublesome since it is likely to be 
forgotton with the next SVN update. When looking into the SVN I have the 
impression there is something going on concerning the history system, however
I couldn't find any documentation.
What is the best practice for the future, in order not to run into any problems 
but still being able to look at the old history (also from within the web-page 
via mhttpd)?

1. If I am not mistaken, the mhttpd.css is hard coded (path/name) into the mhttpd. Wouldn't it be beneficial to have ODB entries where to get is from? This way people could change the look and feel more freely.
   
2. Especially the look and feel of the runlog is unsatisfactorily from my point of view. See . The old style was much more readable. I could recover the old style look and feel by slightly changing the mhttpd.cxx where I changed in show_rawfile(const char*) "dialogTable" to "runlogTable" in the table class. This way I could tinker around with the mhttpd.css by adding the following stuff there:
   
   • adding .runlogTable in line 289 :
     
   • adding some style information for the runlogTable :
     

Understand me right, I mostly like the new style, except the runlog as reported.
Attached you will find the diff's you were asking for. But as pointed out, I
haven't worked so far on CSS and hence this should be checked!!

I understand that the mhttpd.js needs to be the default one, however, mhttpd.css
might be left to the end-user to adopt to their specific needs. I shortly
checked in the mhttpd demon. It checks for the resources path in the ODB. If it
also would check for a CSS name, mhttpd.css could be changed/adopted by the
end-users without breaking things (at least it would then be their one business).

> > If I am not mistaken, the mhttpd.css is hard coded (path/name) into the mhttpd.
> 
> mhttpd.css is served from $MIDASSYS/resources/mhttpd.css. The actual path is
reported on the mhttpd 
> "help" page.
> 
> (I think the internal mhttpd.css and mhttpd.js should be removed as no longer
useful - nothing will work 
> right if the real mhttpd.js and mhttpd.css cannot be served).
> 
> > Especially the look and feel of the runlog is unsatisfactorily from my point
of view.
> 
> persons in charge of implementing the CSS stuff failed to convert quite a few
pages, for example, the elog 
> and the history editor pages were left completely broken. (mostly fixed now).
> 
> so thank you for reporting the runlog breakage, I hope Stefan & co can fix it
quickly. (I cannot do - I have 
> have no runlog pages on any of my test experiments).
> 
> > the old style was much more readable.
> 
> I think the new style is not too bad, except for a few visual artefacts here
and there, the general comment 
> that CSS is too complicated and hard to debug and the fact that over-subtle
colouring yields inconsistent 
> visuals between different monitors and ambient lighting conditions. (persons
who select the colours always 
> respond that "but to me, it looks just fine on my laptop", making it hard to
resolve any issues).
> 
> > I could recover the old style look and feel by slightly changing the mhttpd.cxx
> 
> If you post the patches that fix it for you, I can commit them to midas. (git
diff | mail olchansk@triumf.ca).
> 
> K.O.

16:07:06 [Logger,INFO] Program Logger on host lem00 started
[local:nemu:S]/>q
[nemu@lem00 2014]$ odbedit -e nemu
odbedit: src/odb.c:753: db_update_open_record: Assertion `xkey->notify_count == pkey->notify_count' failed.
Aborted

In the old SVN midas world it was typically such that the Windows dll's and
exe's were ready to be used when checking out. I am not so sure this is the case
for the current version, since when I use the packed dll's  and exe's (e.g.
odbedit.exe) I get the warning that this is running midas 2.0.0 but the current
version (on the linux server) is 2.1.

What does this mean?

1) A little bug in the packed windows part, but up-to-date dll's and exe's?
2) The dll's and exe's are not bundled any more to up-to-date version?

If 2) is the case, I would like to get a hint how to build midas under Windows
(Windows 7), since we still have some few Windows clients.  

Midas has a nice alarm system. I am wondering whether it is easily possible to
get the Alarm/Warning banner also on top of custom pages?!

I think there sneaked in a little bug in the mhttpd: when starting an experiment
from scratch and starting the mhttpd, the Menu Buttons are missing and,
correctly, I get periodic error messages. I expected that the default ODB entry
for the Menu Buttons is create if it doesn't exist. As far as I see this happens
now since the default creation of the 'Menu Buttons' is now tag as an obsolete
feature. In case this is not a bug but a feature, it should documented.

We use the customHeader to display some useful information. Currently I do not
like its style. What about to make it more alike the footer?

I just changed in resources/mhttpd.css

diff --git a/resources/mhttpd.css b/resources/mhttpd.css
index fb0070d..f3264c8 100644
--- a/resources/mhttpd.css
+++ b/resources/mhttpd.css
@@ -280,6 +280,15 @@ table.headerTable td{
        border: none;
 }
 
+div.headerDiv{
+       background-color: #6F6F6F;
+       text-align: center;
+       padding:1em;
+       color:#EEEEEE;
+       border-bottom:1px solid #000000;
+       height:3em;
+}
+
 div.footerDiv{
        background-color: #808080;
        text-align: center;

and

diff --git a/resources/mhttpd.js b/resources/mhttpd.js
index de8bc6c..972c261 100644
--- a/resources/mhttpd.js
+++ b/resources/mhttpd.js
@@ -172,7 +172,7 @@ function mhttpd_goto_page(page) {
 
 function mhttpd_navigation_bar(current_page, path)
 {
-   document.write("<div id=\"customHeader\">\n");
+   document.write("<div class=\"headerDiv\" id=\"customHeader\">\n");
    document.write("</div>\n");
 
    document.write("<div class=\"mnavcss\">\n");

What do you think?

I'd liked very much the possibility to hide away Equipment on the main page. It
is also nice to have the '+' to get it quickly back when needed. However, this
seems not to work anymore (git c9d9d604803). Is this a feature or something went
wrong?

> > I'd liked very much the possibility to hide away Equipment on the main page. It
> > is also nice to have the '+' to get it quickly back when needed. However, this
> > seems not to work anymore (git c9d9d604803). Is this a feature or something went
> > wrong?
> 
> The expansion of the equipment list is handled by a Cookie ("expeq" being 1 or 0). When Konstantin 
> implemented the mongoose server instead of the internal mhttp server, he neglected to evaluate 
> this cookie. I fixed this now (also renamed the cookie to "midas_expeq") in the current development 
> branch. Please check if it's working.
> 
> Stefan

Tested it on two machines and expansion is back and working! Thanks a lot!

Andreas

when I try to stop a run from odbedit I get a core dump.

[ODBEdit1,INFO] Run #31 stopped odbedit: src/system.c:1223: ss_shm_flush:
Assertion `size == mmap_size[handle]' failed. Aborted (core dumped)

midas commit 53af92a5d0...

-----

I checked what happens if I try to stop a run via the mhttpd web-page: this
works! So what is different?

-----

I placed a issue (# 47) on bitbucket as well.

What is the preferred channel to report potential bugs (elog / bitbucket issues)? 

> when I try to stop a run from odbedit I get a core dump.
> 
> [ODBEdit1,INFO] Run #31 stopped odbedit: src/system.c:1223: ss_shm_flush:
> Assertion `size == mmap_size[handle]' failed. Aborted (core dumped)
> 
> midas commit 53af92a5d0...
> 
> -----
> 
> I checked what happens if I try to stop a run via the mhttpd web-page: this
> works! So what is different?
> 
> -----
> 
> I placed a issue (# 47) on bitbucket as well.
> 
> What is the preferred channel to report potential bugs (elog / bitbucket issues)? 

I think I found the problem. Some ODB String values which are **automatically**
generated:

CSS File = STRING : [1024] mhttpd.css
Sqlite dir = STRING : [1024]
History dir = STRING : [1024]
Sound = STRING : [1000] alarm.mp3

are exceeding the MAX_STRING_LENGTH 256 (defined in msystem.h)

It looks as if this screws up quite a bit of the system! When deleting .ODB.SHM and
afterwards try to reload the ODB via a dump I previously made with odbedit, the
following is happening:

1) I get the error message that some strings are too long (exceeding
MAX_STRING_LENGTH). Unfortunately the underlying routine doesn't tell which ODB
variables this is.

2) After this reload, essentially nothing is working anymore. Any client I tried to
start just crashed.

Since it seems that the string length of MAX_STRING_LENGTH is very crucial I would
suggest that db_create_record (or whatever routine is dealing with it) checks for
STRING variables and ensures that they cannot exceed MAX_STRING_LENGTH.

When I shortened in my dump the above variables to MAX_STRING_LENGTH, regenerated the
ODB, also the 'stop' Problem in odbedit is gone.

I stumbled over an oddity which I would like to understand better. Here the
boundaries:
- Enable non-localhost RPC -> y
- Disable RPC hosts check  -> y

1) I am starting a run from ODBedit (start now -v):

07:13:11.272 2017/04/19 [ODBEdit,INFO] Run #26 started

07:13:25.516 2017/04/19 [Logger,LOG] File '/data/max/dlog/lem17_0026.root'
CRC32C checksum: 0x05ca4e7e, 1523383 bytes

On this little test experiment there is not much running, but it already shows
the effect I wanted to understand.

2) I am stopping the run from ODBedit (stop -v):

07:13:25.519 2017/04/19 [ODBEdit,INFO] Run #26 stopped

So, everything looks perfectly fine up to this point.

3) Now the 'strange' thing happens. To any point in time after this, I will stop
ODBEdit which results in the following messages:

07:13:32.335 2017/04/19 [ODBEdit,INFO] Program ODBEdit on host pc7962 stopped

07:13:32.335 2017/04/19 [Logger,ERROR] [midas.c:14079:rpc_server_receive,ERROR]
rpc check ok, abort canceled

This I do NOT understand! It looks as if the Logger (or any other client which
gets the run state transition) thinks that some Client (here ODBEdit) has a
broken connection. At least this is how I understand the comment in midas.c /
rpc_server_receive(). Is something broken in the de-registration from the RPC
server? By the way, all clients where running on the localhost, i.e. no remote
connection used here.

All this only happens if a run transition took place.

Unfortunately I do not understand the system well enough to suggest any fix to
this :-( and hence would appreciate any help. 

A handy feature of the history of the mhttpd is to export the data. However, this 
seems to be broken. It currently only works if the run marker flag is activated by 
fails otherwise.

Description of the problem (starting with 61be7a1):

When starting a new experiment, creating a fresh ODB and than adding the 
directory '/Custom', the mhttpd runs into a problem on RHEL/Fedora, but not on 
Ubuntu and macOS. When trying to open the ODB from within whatever browser I get 
the following error message in the midas message queque:

[mhttpd,ERROR] [mhttpd.cxx:563:rread,ERROR] Cannot read file '/root', read of 
4096 returned -1, errno 21 (Is a directory)

and in the browser I get a popup which tries to save a file called 'root'.

I track this down to the following: in mhttpd, interprete (line 18046) it is 
check if a custom page file exists (ss_file_exist) and if yes, it tries to 'load' 
it. Now, at this stage the variable dec_path contains '/root'.

Here now what goes wrong: ss_file_exist tries to open the given path, and if a 
valid file descriptor is returned it assumes the file exists. This is not 
perfectly correct since it also will get a valid file descriptor is path is an 
accessible directory!

Now for whatever reason, on RHEL/Fedora '/root' will return a valid file 
descriptor, but not on macOS and Ubuntu. Others I haven't tested. A possible fix 
would be to check explicitly if path is a directory and if yes return 0 in 
ss_file_exist (see attached diff).

Perhaps there is cleaner way to deal with this issue?!