I am slowly commiting the changes to the history code. This installement adds
code to mhttpd to use the /History/Tags data (to be) generated by the mlogger.

In the nutshell, the logger fills /History/Tags to "remember" what events,
variables and tags exist in the history files.

This replaces the old code that attempts to guess the contents of history files
by looking at /Equipment tree.

To ease the transition to the new system, I am leaving all the old code alive
and active in the absense of "/History/Tags" entries.

As soon as one starts using the new mlogger (to be commited), the new tags based
mhttpd code will activate itself.

K.O.

Running MIDAS at CERN is proving more challenging than I expected. The network environement is not 
as benign as I am used to (i.e. at TRIUMF) and our machines are being constantly probed by something/
somebody.

This already caused failures in the mserver (fixed in midas svn) and I would like to resolve this problem 
once and for all. The age of "nice networks" is over.

The case of the mserver and for the midas rpc servers (every midas applications listens for midas rpc 
requests, i.e. run transitions) is simple. The list of machines running midas applications is known ahead 
of time, so we can put them all into a list of permitted machines and deny rpc connections to anybody 
else. I propose we keep this list of permitted mserver clients in "/experiment/security/mserver hosts".

(The already existing "/experiment/security/allowed hosts" mechanism is insufficient: it does not 
prevent the mserver from accepting connections from hostile machines, and talking to them, for 
example giving them the list of available experiments. There is a fair amount of code involved and I do 
not presume to certify any of it as hack-proof or even as crash-proof.)

For mhttpd http:// access control, I thought of using tcp_wrappers, but C-API documentation does not 
exist (I looked), the example code in tcpd.c is way too complicated, editing the ACL /etc/hosts.allow 
unnecessarily requires root privileges and non of it would work on Windows.

So I am favouring a home-made hostname or ip-address filter, similar to /etc/hosts.allow, with ACL 
stored, for example, in "/experiment/security/mhttpd hosts".

Any thoughts?

K.O.

I commited a few minor changes to musbstd and mscb code to make them work on
MacOSX (tested on 10.3.9) and Linux (tested on Fedora 6).

The basic functions work with the MSCB USB master, but I still need to
investigate some cases where the connection hangs and usb communications do not
work until the USB cable is unplugged and plugged back in. I see this problem
both on MacOS and Linux.

Important changes:
1) mscb_select_device() does not work on both Linux and MacOS and is disabled.
Please run "msc -d usb0".
2) on Linux, the Makefile should define -DOS_LINUX and -DHAVE_LIBUSB;
   on MacOS, the Makefile should define -DOS_LINUX and -DOS_DARWIN. (This is
because MacOS is treated as a funny type of Linux).
3) when doing USB communications, one has to use the correct endpoint numbers,
which seem to be system dependant and for now, I hard code them in mscb.c for
the tested systems.

There supposed to be no changes to the Windows code, but I cannot test on
Windows, so if somebody does and finds breakage, please let me know.

K.O.

> I commited a few minor changes to musbstd and mscb code...
>
> The basic functions work with the MSCB USB master, but I still need to
> investigate some cases where the connection hangs and usb communications do not
> work until the USB cable is unplugged and plugged back in. I see this problem
> both on MacOS and Linux.

I think I fixed the hangs we see on linux and macos - at the end all I had to do is
issue a usb reset to make mscb communicate again.

Also tested on Linux FC6 and SL4.5.

K.O.

> We run 64-bit MIDAS on RHEL4 with 64-bit ROOT and everything generally works,
> except for compatibility problems with 32-bit MIDAS.
> 
> The big problem is that 64-bit and 32-bit ODB turned out to be incompatible ...

I have now identified 3 data structures that change size when compiled with "-m64":

EVENT_REQUEST: stores a pointer to a function. Pointer size is 4 bytes with -m32 and 8 bytes with -m64.
This structure is part of an array inside BUFFER_HEADER, resulting in a sizable size mismatch between 32
bit and 64 bit shared memory data buffers.

The fix is simple: the function pointer is not used anywhere. Replace is with a "DWORD unused_filler"
makes -m32 and -m64 data buffers compatible. (But breaks compatibility with previous -m64 compiled midas).

CHN_SETTINGS and CHN_STATISTICS: apparently, -m32 and -m64 GCC has different packing rules and in -m64
mode, 4 bytes of padding are added to these data structures. Size size mismatch appears to be benign,
but will result in "size mismatch" complaints from ODB.

The fix is simple: adding "__attribute__ ((__packed__))" to the definition of the data structure makes
-m64 identical to -m32.

The "svn diff" of changes involved is attached below.

The biggest problem here is that making 32-bit ODB and 64-bit ODB compatible requires breaking one or
the other (My proposed changes break the 64-bit version. Alternatively, one could add explicit padding
to these data structures and break the 32-bit ODB).

I think it is important to make 32-bit and 64-bit code compatible: at TRIUMF we have to use a mixed
environment because out latest host computers all run 64-bit Linux while all our VME processors and all
older machines can only run 32-bit code; this incompatibility causes us weekly headaches.

Any thoughts?

K.O.

(this output of svn diff is doctored for clarity)

ladd00:midas$ svn diff
Index: include/midas.h
===================================================================
--- include/midas.h     (revision 3744)
+++ include/midas.h     (working copy)
-   void (*dispatch) (HNDLE, HNDLE, EVENT_HEADER *, void *);
+   INT unused; // was void (*dispatch) (HNDLE, HNDLE, EVENT_HEADER *, void *);
 } EVENT_REQUEST;
 
--- include/msystem.h   (revision 3744)
+++ include/msystem.h   (working copy)

+#define PACKED __attribute__ ((__packed__))  <--- this goes into midas.h inside the #ifdef "we use GCC"
 
-typedef struct {
+typedef struct PACKED { ... CHN_SETTINGS
 
-typedef struct {
+typedef struct PACKED { ... CHN_STATISTICS

> I had to change the pointer type of mvme_read and mvme_write to (void *) instead
> to (mvme_locaddr_t *) to avoid warnings under 64-bit linux. Please adjust your
> VME drivers if necessary.

Updated: vmicvme.c (VMIVME-7750/7805) and gefvme.c (GEFANUC V7865)

K.O.

> I agree to make 32-bit and 64-bit compatible. In the long run, everything will be 64-bit, so I would suggest
> in breaking the 32-bit ODB, add some padding there where needed, probably with some conditional compiling.

I now have the patches to implement this. Changes turned out to be minimal:

1) midas.h: remove unused field "dispatch" from EVENT_REQUEST and bump DATABASE_VERSION from 2 to 3
2) msystem.h: add 32-bit padding to CHN_STATISTICS and CHN_SETTINGS

(Pedantic note: the C/C++ languages permit compilers to arbitrary pad data members inside structures and one is
not supposed to rely on the specific layout of "struct"s, they could changing from day to day depending on
compiler vendor, version, 32/64 bit, optimization level, etc. This is quite silly, but I guess it was the only way
"they" could agree on a standard)

In practice, compilers are will behaved and one can follow simple rules and stay out of trouble.
1) if all data members are of the same size -> no padding
2) do not use "double" (64-bit) and "short" (16-bit), make all char[] arrays divisible by 4 -> size of everything
is 32-bit, see rule 1
3) if you have to use "short", they have to come in pairs to keep everything else aligned to 32-bit
4) if you have to use "double" (or uint64_t), keep them aligned to 64-bit, i.e. struct { int a,b,c; double x;} is
*bad* (4-byte padding may be added between c and x). struct { int a,b,c,d; double x; } is good.

Below are is "svn diff include/midas.h include/msystem.h". These changes have been tested on SL4 32-bit and
64-bit, SL5 32/64, F7 32/64 and SL4/ICC (Intel compiler) 32 bit and 64 bit.

The testing was done by adding checks on sizes of all struct's kept on ODB, i.e.
   assert(sizeof(CHN_SETTINGS        ) ==    640); // ODB v3 with padding
   assert(sizeof(CHN_STATISTICS      ) ==     32); // ODB v3 with padding
   ... etc ...

K.O.

ladd03:midas$ svn diff include/midas.h include/msystem.h
Index: include/midas.h
===================================================================
--- include/midas.h     (revision 3798)
+++ include/midas.h     (working copy)
@@ -38,7 +38,7 @@
  *  @{  */

 /* has to be changed whenever binary ODB format changes */
-#define DATABASE_VERSION 2
+#define DATABASE_VERSION 3

 /* MIDAS version number which will be incremented for every release */
 #define MIDAS_VERSION "2.0.0"
@@ -810,8 +810,6 @@
    short int event_id;           /**< event ID                        */
    short int trigger_mask;       /**< trigger mask                    */
    INT sampling_type;            /**< GET_ALL, GET_SOME, GET_FARM     */
-                                 /**< dispatch function */
-   void (*dispatch) (HNDLE, HNDLE, EVENT_HEADER *, void *);
 } EVENT_REQUEST;

 typedef struct {
Index: include/msystem.h
===================================================================
--- include/msystem.h   (revision 3798)
+++ include/msystem.h   (working copy)
@@ -454,6 +454,7 @@
    INT event_id;
    INT trigger_mask;
    DWORD event_limit;
+   INT pad; // FIXME 64-bit "double" should be 64-bit aligned
    double byte_limit;
    double tape_capacity;
    char subdir_format[32];
@@ -465,6 +466,7 @@
    double bytes_written;
    double bytes_written_total;
    INT files_written;
+   INT pad; // FIXME pad data structure to be 64-bit aligned
 } CHN_STATISTICS;

 typedef struct {
ladd03:midas$

> > I agree to make 32-bit and 64-bit compatible. In the long run, everything will be 64-bit, so I would suggest
> > in breaking the 32-bit ODB, add some padding there where needed, probably with some conditional compiling.
> 
> I now have the patches to implement this. Changes turned out to be minimal:
> 
> 1) midas.h: remove unused field "dispatch" from EVENT_REQUEST and bump DATABASE_VERSION from 2 to 3
> 2) msystem.h: add 32-bit padding to CHN_STATISTICS and CHN_SETTINGS

The padding of CHN_STATISTICS and CHN_SETTINGS is not working right - somehow mhttpd and mlogger keep recreating the
data in ODB and erasing the padding fields. I am looking into this.

K.O.

I am having problems with handling the end-of-run situation in my midas
frontend. I have a device that continuously sends data (over USB) and I read
this data in my "read_event" function.

Everything is good until the end-of-run, at which time this happens:
0) mfe.c calls my read_event() to read the data (loop until the end-of-run
transition)
1) mfe.c calls my end_of_run()
2) here, I tell the device "please stop sending data"
3) all seems good, but wait!!!
4) there is all this data generated between step 0 and step 2 still sitting
inside the device and it has nowhere to go: the run is ended, the output file is
closed, my read_event() will never be called ever again (well, until the next run).

It seems to me mfe.c needs to have one more function, something like
"pre_end_of_run()" that works like this:
0) mfe.c calls my read_event() to read the data (loop until the end-of-run
transition)
1) mfe.c calls pre_end_of_run(), here I tell the device to stop sending data
2) mfe.c calls read_event() for the very last time, to give me the opportunity
to read and send away any data I still may have.
3) mfe.c calls the end_of_run(). The run is truely finished.

Any thoughts?

K.O.

> > I commited the latest driver for the Wiener CCUSB USB-CAMAC driver. It
> > implements all functions from mcstd.h and has been tested to be plug-compatible
> > with at least one of our CAMAC frontends. K.O.

Well, it took almost a year to finish an updated driver, which has now been
commited to MIDAS SVN (see http://savannah.psi.ch/viewcvs/trunk/drivers/camac/ccusb/?root=midas).

This supports ccusb firmware release 0x402. With earlier firmware, simple CAMAC operations should work,
but to use the readout list feature one has to have the latest main firmware (0x402 as of today) and the latest CPLD
firmware.

The driver kit includes:
- the "ccusb" driver which implements the MIDAS mcstd.h CAMAC interface;
- test_ccusb to probe the interface and generally make the lights flash;
- ccusb_flash for updating the ccusb main firmware (assembled from bits and pieces found on the CCUSB driver CD);
- feccusb, an example midas frontend, which uses the ccusb readout list feature and has extensive error handling,
should be good enough for production use (unlike the Wiener libxxusb drivers, which lack basic error handling).
- analyzer.cxx, an rootana-based example on how to decode the ccusb data;
- README file with release notes.

If you use this driver, please drop me an email (even if it works perfectly for you, hah!) - the ccusb device is very
nice but can be hard to use and I would like to hear about problems other people have with it.

Today's version of the README files is attached below:

MIDAS driver for the Wiener/JTec CC-USB CAMAC-USB interface.

Date: 22-AUG-2007/KO

Note 1: The CC-USB interface comes with a CD which contains manuals,
firmware files, Windows and Linux software. The Wiener/JTec driver
is called "libxxusb". These MIDAS/musbstd drivers were written before
libxxusb bacame available and do not use libxxusb.

This driver implements the MIDAS CAMAC interafce "mcstd.h" using
the MIDAS USB interface musbstd.h.

Note 2: There exist many revisions of CCUSB firmware. Basic CAMAC
access works in all of them, but the "readout list" feature seems
to be only functional with firmware revision 0x402 or older and
with CPLD revisions CC_atmmgr_101406.jed, CC_datamgr_021905.jed,
CC_lammgr_brdcst_041906.jed or older.

To upgrade the main CCUSB firmware, follow instructions from
the CCUSB manual. On Linux, one can use the ccusb_flash
program included with these MIDAS drivers. It is a copy
of ccusb_flash from the Wiener CD, with all the pieces
assembled into one place and with a working Makefile. (I am too
lazy to add the flashing bits to the ccusb.c driver).

To upgrade the CPLD firmware, one needs a Xilinx JTag programmer
cable (we use a "parallel port to JTag" cable provided by Wiener),
and the Xilinx software (on Linux, we use Xilinx91i). For successful
upgrade, follow instructions from Xilinx and Wiener.

Note 3: Before starting to use the CCUSB interface, one should obtain
the latest version of the CCUSB manual and firmware by downloading
the latest version the CCUSB driver CD from the Wiener web
site (registration required)

Note 4: The example CCUSB frontend assumes this hardware configuration:
LeCroy 2249A 12 channel ADC in slot 20, Kinetic Systems 3615 6 channel
scaler in slot 12. NIM trigger input connected to CCUSB input "I1"
firing at 10-100 Hz. Without the external trigger CCUSB will not
generate any data and the frontend will only give "data timeout"
errors. With the trigger, the LED on the scaler should flash at 1 Hz
and the LEDs on the CCUSB should flash at the trigger rate.

Note 5: The CCUSB interface does not reliably power up in some CAMAC
crates (this has something to do with the sequence in which
different voltages start at different times with different CAMAC
power supplies). Some newer CCUSB modules may have this
problem fixed in the hardware and in the CPLD firmware. For modules
exhibiting this problem (i.e. no USB communication after power up),
try to cycle the power several time, or implement the "hardware reset
switch" (ask Wiener).

Note 6: The CCUSB firmware is very fickle and would crash if you look
at it the wrong way. This MIDAS driver tries to avoid all known crashers
and together with the example frontend, can recover from some
of them. Other crashes cannot be recovered from other than by
a hardware reset or power cycle.

//end

> > > I agree to make 32-bit and 64-bit compatible. In the long run, everything will be 64-bit, so I would suggest
> > > in breaking the 32-bit ODB, add some padding there where needed, probably with some conditional compiling.
> > 1) midas.h: remove unused field "dispatch" from EVENT_REQUEST and bump DATABASE_VERSION from 2 to 3
> > 2) msystem.h: add 32-bit padding to CHN_STATISTICS and CHN_SETTINGS

I am now trying a different solution of to fixing the issue of CHN_STATISTICS and CHN_SETTINGS changing size.

1) midas.h: (same as before) remove unused field "dispatch" from EVENT_REQUEST and bump DATABASE_VERSION from 2 to 3
2) msystem.h: in CHN_STATISTICS and CHN_SETTINGS change type of "event_limit" and "files_written" from int to "double".

Below are the latest ODBv3 meta patches:

ladd03:midas$ svn diff
Index: include/midas.h
===================================================================
--- include/midas.h     (revision 3844)
+++ include/midas.h     (working copy)
 /* has to be changed whenever binary ODB format changes */
-#define DATABASE_VERSION 2
+#define DATABASE_VERSION 3
.........
    short int trigger_mask;       /**< trigger mask                    */
    INT sampling_type;            /**< GET_ALL, GET_SOME, GET_FARM     */
-                                 /**< dispatch function */
-   void (*dispatch) (HNDLE, HNDLE, EVENT_HEADER *, void *);
 } EVENT_REQUEST;

Index: include/msystem.h
===================================================================
--- include/msystem.h   (revision 3845)
+++ include/msystem.h   (working copy)
-"Event limit = DWORD : 0",\
+"Event limit = DOUBLE : 0",\
..................
-"Files written = INT : 0",\
+"Files written = DOUBLE : 0",\
..................
-   DWORD event_limit;
+   double event_limit;
..................
-   INT files_written;
+   double files_written;

K.O.

I now commited the changes to mlogger (mlogger.c, msystem.h) implementing data
compression using zlib (svn revision 3845)

To enable compression, observe that mlogger is compiled with -DHAVE_ZLIB (see
the Makefile), in "/Logger/Channels/NNN/Settings", set "compression" to "1" and
the filename to "run%05d.mid.gz" (note the suffix ".gz").

In the Makefile, I only enabled HAVE_ZLIB for Linux, as that is the only
platform I tested. If somebody can test compression on Windows, please do and
let us know.

My ROOT analyzer (rootana) package can read compressed MIDAS files directly and
if one wants to add this capability to other MIDAS-related packages, one is
welcome to use my TMidasFile.cxx as an example
(http://ladd00.triumf.ca/viewcvs/rootana/trunk/TMidasFile.cxx?view=markup).

K.O.

The ROODY online histogram viewer and the ROOTANA midas analyzer toolkit have been updated to work 
with ROOT version 5.16 and tested on Linux (SL4.4) and MacOS (10.4.10/PPC).

This update includes the library called "TNetDirectory" for access to remote ROOT objects. This library is 
still under development, but is complete enough for use with ROODY. To try it, please specify -P9091 in 
rootana and -Plocalhost:9091 in ROODY.

K.O.

> > I hope people find this program useful. If you have any feedback (patches, bug
> > reports, requests for improvements), please post them as replies to this forum
> > message.
> 
> I wouldn't mind putting this into the midas distribution. Put it under utils/, add
> an entry to the Makefile, and fix that warning:
> 
> 
> mhdump.cxx: In function `int readHstFile(FILE*)':
> mhdump.cxx:161: warning: comparison between signed and unsigned integer expressions

Done and done.

The program mhdump, a standalone decoder for midas history files, is now in midas svn.

K.O.

These changes to make 32-bit and 64-bit ODB binary compatible with each other are now commited to midas svn, revision 4080.

Starting with this revision, ODB version changes from 2 to 3, breaking binary compatibility with previous releases.

Before upgrading to this revision, save your ODB as an XML file, *and* try to reload it, to catch any potential problems with parsing of the XML file.

Part of this commit are checks for sizes of important midas data structures stored in ODB shared memory - if the compiled size does not match the expected 
value, binary compatibility is broken and the program will abort - to avoid further corruption of ODB shared memory. This feature is only enabled on Linux and 
it is expected to trigger only on compiler malfunctions (generates wrong data size) and on accidental or intentional changes to important data structures in 
midas, to warn the user that they broke ODB binary compatibility.

K.O.

> > > > I agree to make 32-bit and 64-bit compatible. In the long run, everything will be 64-bit, so I would suggest
> > > > in breaking the 32-bit ODB, add some padding there where needed, probably with some conditional compiling.
> > > 1) midas.h: remove unused field "dispatch" from EVENT_REQUEST and bump DATABASE_VERSION from 2 to 3
> > > 2) msystem.h: add 32-bit padding to CHN_STATISTICS and CHN_SETTINGS
> 
> I am now trying a different solution of to fixing the issue of CHN_STATISTICS and CHN_SETTINGS changing size.
> 
> 1) midas.h: (same as before) remove unused field "dispatch" from EVENT_REQUEST and bump DATABASE_VERSION from 2 to 3
> 2) msystem.h: in CHN_STATISTICS and CHN_SETTINGS change type of "event_limit" and "files_written" from int to "double".
> 
> Below are the latest ODBv3 meta patches:
> 
> ladd03:midas$ svn diff
> Index: include/midas.h
> ===================================================================
> --- include/midas.h     (revision 3844)
> +++ include/midas.h     (working copy)
>  /* has to be changed whenever binary ODB format changes */
> -#define DATABASE_VERSION 2
> +#define DATABASE_VERSION 3
> .........
>     short int trigger_mask;       /**< trigger mask                    */
>     INT sampling_type;            /**< GET_ALL, GET_SOME, GET_FARM     */
> -                                 /**< dispatch function */
> -   void (*dispatch) (HNDLE, HNDLE, EVENT_HEADER *, void *);
>  } EVENT_REQUEST;
> 
> Index: include/msystem.h
> ===================================================================
> --- include/msystem.h   (revision 3845)
> +++ include/msystem.h   (working copy)
> -"Event limit = DWORD : 0",\
> +"Event limit = DOUBLE : 0",\
> ..................
> -"Files written = INT : 0",\
> +"Files written = DOUBLE : 0",\
> ..................
> -   DWORD event_limit;
> +   double event_limit;
> ..................
> -   INT files_written;
> +   double files_written;
> 
> K.O.

> A major change was made to mhttpd, changing all internal URLs to relative paths.
> This allows proxy access to mhttpd via an apache server for example, which might
> be needed to securely access an experiment from outside the lab through a
> firewall.

It is good to see improvements to the MIDAS URLs. We have been successfully running
mhttpd behind an apache SSL/HTTPS proxy without these changes, but our case was very
limited to one experiment, one mhttpd behind one proxy. I hope to test these changes
in the near future at CERN, I guess we will hear if things broke. I am especialloy
worried about the function for "split mhttpd history generator" via "/History/URL".
I remember it was hard to get it right and I hope if this function did not survive
this update, it will be easy to resurrect.
K.O.

> The midas history system always had the problem that the database can get
> corrupted if the disk gets full where the history records (*.hst & *.idx) are
> stored.

Stefan - big thanks for fixing this problem - it is one of those cases "how come I
did not think of do it!".

This change should fix the last remaining problem with history at CERN - we seem to
be unable to avoid running out of disk space once in a while (run away scripts, fat
fingers, etc) and history got corrupted every time.

But to make things more interesting we had another history outage this week - we
happen to write history files to an NFS server (not recommened! do not do this!) and
when the NFS server had a glitch, history files got corrupted - because during the
glitch NFS was not available, I think this roll-back feature would not have helped.

Anyhow, I now have a patch to allow hs_read() to "skip the bad spots" in the history
files. (hs_gen_index() also needs a patch).

In the nutshell, if invalid history data is detected, the code continues to read the
data one byte at a time, looking for valid event_id markers (etc).

The code looks sane by inspection, and if nobody objects, I would like to commit it
in the next few days.

Here is the diff against src/history.c rev 4114

Index: history.c
===================================================================
--- history.c	(revision 4118)
+++ history.c	(working copy)
@@ -129,6 +129,7 @@
    HIST_RECORD rec;
    INDEX_RECORD irec;
    DEF_RECORD def_rec;
+   int recovering = 0;
 
    printf("Recovering index files...\n");
 
@@ -171,7 +172,7 @@
 
          /* skip tags */
          lseek(fh, rec.data_size, SEEK_CUR);
-      } else {
+      } else if (rec.record_type == RT_DATA) {
          /* write index record */
          irec.event_id = rec.event_id;
          irec.time = rec.time;
@@ -180,6 +181,15 @@
 
          /* skip data */
          lseek(fh, rec.data_size, SEEK_CUR);
+      } else {
+
+         if (!recovering)
+            cm_msg(MERROR, "hs_gen_index", "broken history file %d, trying to
recover", (int)ltime);
+
+	 recovering = 1;
+         lseek(fh, -sizeof(rec)+1, SEEK_CUR);
+
+         continue;
       }
 
    } while (TRUE);
@@ -220,6 +230,7 @@
    time_t lt;
    int fh, fhd, fhi;
    struct tm *tms;
+   int idxsize = 0;
 
    if (*ltime == 0)
       *ltime = ss_time();
@@ -250,12 +261,15 @@
    hs_open_file(*ltime, "idf", O_RDONLY, &fhd);
    hs_open_file(*ltime, "idx", O_RDONLY, &fhi);
 
+   if (fhi >= 0)
+     idxsize = lseek(fhi, 0, SEEK_END);
+
    close(fh);
    close(fhd);
    close(fhi);
 
    /* generate them if not */
-   if (fhd < 0 || fhi < 0)
+   if (fhd < 0 || fhi < 0 || idxsize == 0)
       hs_gen_index(*ltime);
 
    return HS_SUCCESS;
@@ -1480,12 +1494,33 @@
             i = -1;
             M_FREE(cache);
             cache = NULL;
-         } else
+         } else {
+
+	 try_again:
+
             i = sizeof(irec);
-
-         if (cp < cache_size) {
             memcpy(&irec, cache + cp, sizeof(irec));
             cp += sizeof(irec);
+
+	    /* if history file is broken ... */
+	    if (irec.time < last_irec_time) {
+	      //printf("time %d -> %d, cache_size %d, cp %d\n", last_irec_time, irec.time,
cache_size, cp);
+
+	      //printf("Seeking next record...\n");
+
+	      while (cp < cache_size)
+		{
+		  DWORD* evidp = (DWORD*)(cache + cp);
+		  if (*evidp == event_id) {
+		    //printf("Found at cp %d\n", cp);
+		    goto try_again;
+		  }
+
+		  cp++;
+		}
+
+	      i = -1;
+	    }
          }
       } else
          i = read(fhi, (char *) &irec, sizeof(irec));

K.O.

I now merged almost all the mhttpd changes from CERN AD-5/ALPHA. Only the code
for mhttpd HTTP:// access control list remains unmerged.

Changes to the history display code merged from ALPHA: 
- add option to show latest values of history variables: "show values of
variables" check box on the history config panel 
- add custom labels for each variables: instead of midas variable name, history
plots would show the text entered into the "label" text area 
- show history errors on the plot: before, if one out of 10 history variables
could not be plotted, nothing was shown at all, now all variables are \
show, those that could not be read with hs_read() show the error code 
- the selection of which variables to plot is alphanumerically sorted (adc11 >
adc9) [this code is not active for standard midas because mlogger sup\
port has not yet been committed] 
- the selection of which variables to plot shows the last variable selected, not
the first one - useful when entering variables from a long list [th\
is code is not active for standard midas because mlogger support has not yet
been committed] 
 
These changes have been extensively tested since last Summer at the AD-5 ALPHA
expt at CERN. 
I could only do minimal testing for this merged code, so if there are any errors, 
they would most likely be merge errors. This new code will be heavily used at
TRIUMF, 
so if any errors got any, we hope to flush them out quickly. 
 
As noted, mlogger support for some of the mhttpd functions is not in standard
midas yet. It will be committed shortly. 

K.O.

I now encountered a new problem with mhttpd - I connect using the Safari 3.0.4 browser, go to the 
"Programs" page, press the button "Start feplc" (or any other "start" button) and instead of starting this 
program, I get an error in the browser, funny entries in ODB in "/Programs", corrupted ODB and a spew 
of messages in the midas log file about the mess. ODB has to be reloaded from backup to recover.

Investigation shows that the culprit is odd bahaviour of the "redirect()" function:

    /* start command */
    if (*getparam("Start")) {
       /* for NT: close reply socket before starting subprocess */
-      redirect2("?cmd=programs");
+      redirect2("/?cmd=programs");

The version without "/" makes Safari explode - it appends the "?cmd..." stuff to the existing URL, which 
already has the "?cmd..." tags, making a mess.

Firefox accepts either version.

ODB corruption happens here:
 
       sprintf(str, "/Programs/%s/Start command", name);
-      db_get_value(hDB, 0, str, command, &size, TID_STRING, TRUE);
+      db_get_value(hDB, 0, str, command, &size, TID_STRING, FALSE);
       if (command[0]) {
          ss_system(command);

It looks like db_get_value() would corrupt ODB if given funny "str". When Safari explodes,
funny strings are generated.

The simple fix is to replace "TRUE" with "FALSE", then at least db_get_value() does not try to make bogus 
entries in ODB.

The "Stop" command has the same problem, but does not currupt ODB - there is no db_get_value() in 
that code path.

I am reporting this "fresh" as I made one of our daq systems work again.

I did not investigate the history of changes to this "redirect" command (perhaps it was broken in the 
recent reorganisation of midas urls?), what versions of Safari work or not.

K.O.

It looks like ODB function extract_key() will overwrite the array pointed to by "key_name" if given an odb 
path with very long names (as seems to happen when redirection explodes in the Safari web browser, via 
db_get_value(TRUE) via mhttpd "start program" button). All  callers of this function seem to provide 256 
byte strings, so the problem would not show up in normal use - only when abnormal odb paths are being 
parsed. Proposed solution is to add a "length" argument to this function. (Actually ODB path elements 
should be restricted to NAME_LENGTH (32 bytes), right?). K.O.