;+ ; NAME: ; GET_SEGMENTS ; PURPOSE: ; Reads all segment records from a file, in an optimized manner, ; and returns a string list of information for each segment. ; CATEGORY: ; OVRO APC DATA-ANALYSIS ; CALLING SEQUENCE: ; seglist = get_segments(a,nrec[,srec][,lrec]) ; INPUTS: ; a the ASSOC variable associated with the file to be ; examined. ; nrec the number of records currently in the file ; OPTIONAL (KEYWORD) INPUT PARAMETERS: ; srec the start record number at which to start reading ; segments. If omitted, the start record is 1. ; lrec the end record number at which to stop reading ; segments. If omitted, the end record is NREC ; ROUTINES CALLED: ; getdata, getlrecn, tl_decode, get_scantyp, get_segtyp, get_endtyp ; OUTPUTS: ; seglist a string array (list) of segment information, or ; -1 if file could not be opened, or 0 if file ; contained no segments. ; COMMENTS: ; SIDE EFFECTS: ; RESTRICTIONS: ; MODIFICATION HISTORY: ; Written 25-Sep-1997 by Dale Gary ; 10-Jan-1998 DG ; Added code to find the end of actual data in the case of an ; untruncated real-time data file, which may have fill (zero) ; data at the end of the file. ; 11-Jan-1998 DG ; Changed due to use of OPENARC routine, and to use ASSOC ; variable as argument rather than filename. ; 14-Jan-1998 DG ; Changed to honor return of -1 from getlrecn, indicating ; that the file is empty. ; 22-Jun-1998 DG ; Changed calls a(rec) to getdata(rec,a) so that routines will ; work on a UNIX system. ; 07-Sep-1998 DG ; Added code to work with segments within segments, although ; it only works properly if the intervening segment is only ; one record long. ; 07-Jan-1999 DG ; Added code to find the end of scan segments and write an ; entry for each in the output array. ; 13-Mar-1999 DG ; Fixed problem with CVDOY returning an Invalid day of year message, ; when the last record was all zeroes. ; 17-Mar-1999 DG ; Added ENDCODE response to EOS segment ; 16-May-1999 DG ; Added SCRDUMP segment ; 18-May-1999 DG ; Several changes to fix problems with new LAUNCHER behavior, ; segments not in scans, and scans with no data segments. ; 01-Nov-1999 DG ; Added a line to fix crash on checking an empty file (lastrec = 0). ; 23-Jul-2000 DG ; Slight change to deal with zero length segments (generally a ; blank record). ; 27-Jul-2000 DG ; Added optional start and end record arguments, to speed up ; finding segments when a restricted record range is to be searched. ; 25-Jan-2001 DG ; Added code to skip DIALOG_HISTORY records, to fix a major problem ; caused by them. ; 18-Jan-2006 DG ; Fixed problem with empty records. Using NSEGREC as a UINT means that ; what used to be -1 is now 65535, so test for this case explicitly. ;- function get_segments,a,nrec,srec,lrec ; Find the last record that contains good data if (n_elements(lrec) ne 0) then begin lastrec = lrec endif else begin lastrec = getlrecn(a,nrec) IF (lastrec EQ -1) THEN return,'No records in file.' IF (lastrec EQ 0) THEN return,'No records yet.' endelse if (n_elements(srec) eq 0) then srec = 1 seglist = ' ' ; Set the last record as end of scan, in case there is no EOS record. rec = lastrec d = getdata(lastrec-1,a) escan = uint(d[0]) ; Now search backward through file, finding all of the ; beginning records of each segment while (long(rec) gt srec-1) do begin skip: d = getdata(rec-1,a) ; Read a record (should be last record of a segment) tls = tl_decode(d) if (tls.segmentcode eq !SEGM.DILOGHIST or tls.segmentcode eq !SEGM.MONITOR $ or tls.segmentcode eq !SEGM.SCRDUMP) then begin rec = rec - 1 goto,skip endif erec = uint(d[0]) ; The file rec number of this record nsegrec = uint(d[3]) ; Get the seg rec number of this record ; print,tls.segmentcode,rec,nsegrec ; Debugging aid if (nsegrec eq 65535 or nsegrec eq 0) then begin ; Empty record, so skip it rec = rec - 1 endif else begin data = getdata((rec - nsegrec)>0,a) ; Now read the first segment record of this segment tls = tl_decode(data) ; Decode the time/label bytes of this record try = 0 if (tls.nrs ne 1) then begin ; This was supposed to be the first record of a segment, but it is not. ; Probably this is because this segment contains other segments, which ; extends the total length beyond that expected. Try again... try2: try = try + 1 nsegrec = nsegrec + tls.nrs - 1 data = getdata((rec - nsegrec)>0,a) tls = tl_decode(data) ivlist = ' ' if (tls.nrs ne 1) then begin ; Try one more time: if (try le 3) then goto,try2 ; Not having much luck getting synchronized, so give up ans = widget_message([$ 'Error: File has unexpected structure.',$ 'Continue anyway? (Select "No" to stop',$ 'the program for debugging.)'],/QUESTION) IF (ans EQ 'No') THEN BEGIN print,'Record with segrec=',tls.nrs,' was not first record in segment??' stop ENDIF endif endif ; If this is a data segment, the end record (rec) is also the ; end of scan record. if (tls.segmentcode eq !SEGM.HEADER) then begin ; If this is a scan header segment, format the line in a special way scnstr = get_scntyp(tls.scancode) segstr = tls.yrday+ $ string(tls.nrc,escan,format='('' REC'',1X,I5.5,'':'',I5.5)')+ $ ' Header: '+scnstr escan = tls.nrc-1 endif else begin ; Otherwise, format the line for the segment segtypstr = get_segtyp(tls.segmentcode) if (strmid(segtypstr,0,7) eq 'ENCODER') then begin nctyp = ['1H-','1D-','2H-','2D-'] segtypstr = nctyp((data[12]-1)>0<3)+segtypstr endif segstr = ' '+strmid(tls.timstr,0,9)+ $ string(tls.nrc,erec,format='(2X,I5.5,'':'',I5.5)')+' '+segtypstr ; If this is a data segment, the last record of the segment should ; be an EOS record so check and see. If so, we want to write a ; segment line for it to indicate the end of the scan. if (tls.segmentcode eq !SEGM.DATA) then begin ; We have to do something special for the last record if (erec eq lastrec) then escan = erec else escan = erec data = getdata(escan-1,a) ; Check if data are good. If data(0) = 0, no point in checking segmentcode if (data(0) ne 0) then begin tls = tl_decode(data) ; Is this last record an EOS record? if (tls.segmentcode eq !SEGM.EOS) then begin ; Yes, it is an EOS record, so format a line for it. segtypstr = get_segtyp(tls.segmentcode) endcode = ishft(data(1023),-8) and 'FF'x if (endcode eq 'FF'x) then endtypstr = '' $ else endtypstr = ' due to '+get_endtyp(endcode) segstr = [' '+strmid(tls.timstr,0,9)+ $ string(escan,escan,format='(2X,I5.5,'':'',I5.5)')+ $ ' '+segtypstr+endtypstr,segstr] endif endif endif endelse seglist = [seglist,segstr] ; Add the formatted line to the list rec = (rec - nsegrec)>0 ; Skip to end of next higher segment (or zero) endelse endwhile ; Sort the list so that the start records are in order: nsegs = n_elements(seglist) if (nsegs eq 1) then return,0 seglist = seglist[sort(strmid(seglist,13,5))] return,seglist(1:nsegs-1) end