1: # The LearningOnline Network with CAPA
2: # (Publication Handler
3: #
4: # $Id: loncoursedata.pm,v 1.8 2002/07/30 21:31:48 stredwic Exp $
5: #
6: # Copyright Michigan State University Board of Trustees
7: #
8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
9: #
10: # LON-CAPA is free software; you can redistribute it and/or modify
11: # it under the terms of the GNU General Public License as published by
12: # the Free Software Foundation; either version 2 of the License, or
13: # (at your option) any later version.
14: #
15: # LON-CAPA is distributed in the hope that it will be useful,
16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18: # GNU General Public License for more details.
19: #
20: # You should have received a copy of the GNU General Public License
21: # along with LON-CAPA; if not, write to the Free Software
22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23: #
24: # /home/httpd/html/adm/gpl.txt
25: #
26: # http://www.lon-capa.org/
27: #
28: ###
29:
30: =pod
31:
32: =head1 NAME
33:
34: loncoursedata
35:
36: =head1 SYNOPSIS
37:
38: Set of functions that download and process student information.
39:
40: =head1 PACKAGES USED
41:
42: Apache::Constants qw(:common :http)
43: Apache::lonnet()
44: HTML::TokeParser
45: GDBM_File
46:
47: =cut
48:
49: package Apache::loncoursedata;
50:
51: use strict;
52: use Apache::Constants qw(:common :http);
53: use Apache::lonnet();
54: use HTML::TokeParser;
55: use GDBM_File;
56:
57: =pod
58:
59: =head1 DOWNLOAD INFORMATION
60:
61: This section contains all the files that get data from other servers
62: and/or itself. There is one function that has a call to get remote
63: information but isn't included here which is ProcessTopLevelMap. The
64: usage was small enough to be ignored, but that portion may be moved
65: here in the future.
66:
67: =cut
68:
69: # ----- DOWNLOAD INFORMATION -------------------------------------------
70:
71: =pod
72:
73: =item &DownloadClasslist()
74:
75: Collects lastname, generation, middlename, firstname, PID, and section for each
76: student from their environment database. The list of students is built from
77: collecting a classlist for the course that is to be displayed.
78:
79: =over 4
80:
81: Input: $courseID, $c
82:
83: $courseID: The id of the course
84:
85: $c: The connection class that can determine if the browser has aborted. It
86: is used to short circuit this function so that it doesn't continue to
87: get information when there is no need.
88:
89: Output: \%classlist
90:
91: \%classlist: A pointer to a hash containing the following data:
92:
93: -A list of student name:domain (as keys) (known below as $name)
94:
95: -A hash pointer for each student containing lastname, generation, firstname,
96: middlename, and PID : Key is $name.'studentInformation'
97:
98: -A hash pointer to each students section data : Key is $name.section
99:
100: =back
101:
102: =cut
103:
104: sub DownloadClasslist {
105: my ($courseID, $lastDownloadTime, $c)=@_;
106: my ($courseDomain,$courseNumber)=split(/\_/,$courseID);
107: my %classlist;
108:
109: my $modifiedTime = &GetFileTimestamp($courseDomain, $courseNumber,
110: 'classlist.db',
111: $Apache::lonnet::perlvar{'lonUsersDir'});
112:
113: if($lastDownloadTime ne 'Not downloaded' &&
114: $lastDownloadTime >= $modifiedTime && $modifiedTime >= 0) {
115: $classlist{'lastDownloadTime'}=time;
116: $classlist{'UpToDate'} = 'true';
117: return \%classlist;
118: }
119:
120: %classlist=&Apache::lonnet::dump('classlist',$courseDomain, $courseNumber);
121: my ($checkForError)=keys (%classlist);
122: if($checkForError =~ /^(con_lost|error|no_such_host)/i) {
123: return \%classlist;
124: }
125:
126: foreach my $name (keys(%classlist)) {
127: if($c->aborted()) {
128: $classlist{'error'}='aborted';
129: return \%classlist;
130: }
131:
132: my ($studentName,$studentDomain) = split(/\:/,$name);
133: # Download student environment data, specifically the full name and id.
134: my %studentInformation=&Apache::lonnet::get('environment',
135: ['lastname','generation',
136: 'firstname','middlename',
137: 'id'],
138: $studentDomain,
139: $studentName);
140: $classlist{$name.':studentInformation'}=\%studentInformation;
141:
142: if($c->aborted()) {
143: $classlist{'error'}='aborted';
144: return \%classlist;
145: }
146:
147: #Section
148: my %section=&Apache::lonnet::dump('roles',$studentDomain,$studentName);
149: $classlist{$name.':sections'}=\%section;
150: }
151:
152: $classlist{'UpToDate'} = 'false';
153: $classlist{'lastDownloadTime'}=time;
154:
155: return \%classlist;
156: }
157:
158: =pod
159:
160: =item &DownloadCourseInformation()
161:
162: Dump of all the course information for a single student. There is no
163: pruning of data, it is all stored in a hash and returned. It also
164: checks the timestamp of the students course database file and only downloads
165: if it has been modified since the last download.
166:
167: =over 4
168:
169: Input: $name, $courseID
170:
171: $name: student name:domain
172:
173: $courseID: The id of the course
174:
175: Output: \%courseData
176:
177: \%courseData: A hash pointer to the raw data from the student's course
178: database.
179:
180: =back
181:
182: =cut
183:
184: sub DownloadCourseInformation {
185: my ($namedata,$courseID,$lastDownloadTime)=@_;
186: my %courseData;
187: my ($name,$domain) = split(/\:/,$namedata);
188:
189: my $modifiedTime = &GetFileTimestamp($domain, $name,
190: $courseID.'.db',
191: $Apache::lonnet::perlvar{'lonUsersDir'});
192:
193: if($lastDownloadTime >= $modifiedTime) {
194: $courseData{'lastDownloadTime'}=time;
195: $courseData{'UpToDate'} = 'true';
196: return \%courseData;
197: }
198:
199: # Download course data
200: %courseData=&Apache::lonnet::dump($courseID, $domain, $name);
201: $courseData{'UpToDate'} = 'false';
202: $courseData{'lastDownloadTime'}=time;
203: return \%courseData;
204: }
205:
206: # ----- END DOWNLOAD INFORMATION ---------------------------------------
207:
208: =pod
209:
210: =head1 PROCESSING FUNCTIONS
211:
212: These functions process all the data for all the students. Also, they
213: are the only functions that access the cache database for writing. Thus
214: they are the only functions that cache data. The downloading and caching
215: were separated to reduce problems with stopping downloading then can't
216: tie hash to database later.
217:
218: =cut
219:
220: # ----- PROCESSING FUNCTIONS ---------------------------------------
221:
222: =pod
223:
224: =item &ProcessTopResourceMap()
225:
226: Trace through the "big hash" created in rat/lonuserstate.pm::loadmap.
227: Basically, this function organizes a subset of the data and stores it in
228: cached data. The data stored is the problems, sequences, sequence titles,
229: parts of problems, and their ordering. Column width information is also
230: partially handled here on a per sequence basis.
231:
232: =over 4
233:
234: Input: $cache, $c
235:
236: $cache: A pointer to a hash to store the information
237:
238: $c: The connection class used to determine if an abort has been sent to the
239: browser
240:
241: Output: A string that contains an error message or "OK" if everything went
242: smoothly.
243:
244: =back
245:
246: =cut
247:
248: sub ProcessTopResourceMap {
249: my ($cache,$c)=@_;
250: my %hash;
251: my $fn=$ENV{'request.course.fn'};
252: if(-e "$fn.db") {
253: my $tieTries=0;
254: while($tieTries < 3) {
255: if($c->aborted()) {
256: return;
257: }
258: if(tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER,0640)) {
259: last;
260: }
261: $tieTries++;
262: sleep 1;
263: }
264: if($tieTries >= 3) {
265: return 'Coursemap undefined.';
266: }
267: } else {
268: return 'Can not open Coursemap.';
269: }
270:
271: # Initialize state machine. Set information pointing to top level map.
272: my (@sequences, @currentResource, @finishResource);
273: my ($currentSequence, $currentResourceID, $lastResourceID);
274:
275: $currentResourceID=$hash{'ids_/res/'.$ENV{'request.course.uri'}};
276: push(@currentResource, $currentResourceID);
277: $lastResourceID=-1;
278: $currentSequence=-1;
279: my $topLevelSequenceNumber = $currentSequence;
280:
281: while(1) {
282: if($c->aborted()) {
283: last;
284: }
285: # HANDLE NEW SEQUENCE!
286: #if page || sequence
287: if(defined($hash{'map_pc_'.$hash{'src_'.$currentResourceID}})) {
288: push(@sequences, $currentSequence);
289: push(@currentResource, $currentResourceID);
290: push(@finishResource, $lastResourceID);
291:
292: $currentSequence=$hash{'map_pc_'.$hash{'src_'.$currentResourceID}};
293:
294: # Mark sequence as containing problems. If it doesn't, then
295: # it will be removed when processing for this sequence is
296: # complete. This allows the problems in a sequence
297: # to be outputed before problems in the subsequences
298: if(!defined($cache->{'orderedSequences'})) {
299: $cache->{'orderedSequences'}=$currentSequence;
300: } else {
301: $cache->{'orderedSequences'}.=':'.$currentSequence;
302: }
303:
304: $lastResourceID=$hash{'map_finish_'.
305: $hash{'src_'.$currentResourceID}};
306: $currentResourceID=$hash{'map_start_'.
307: $hash{'src_'.$currentResourceID}};
308:
309: if(!($currentResourceID) || !($lastResourceID)) {
310: $currentSequence=pop(@sequences);
311: $currentResourceID=pop(@currentResource);
312: $lastResourceID=pop(@finishResource);
313: if($currentSequence eq $topLevelSequenceNumber) {
314: last;
315: }
316: }
317: }
318:
319: # Handle gradable resources: exams, problems, etc
320: $currentResourceID=~/(\d+)\.(\d+)/;
321: my $partA=$1;
322: my $partB=$2;
323: if($hash{'src_'.$currentResourceID}=~
324: /\.(problem|exam|quiz|assess|survey|form)$/ &&
325: $partA eq $currentSequence) {
326: my $Problem = &Apache::lonnet::symbclean(
327: &Apache::lonnet::declutter($hash{'map_id_'.$partA}).
328: '___'.$partB.'___'.
329: &Apache::lonnet::declutter($hash{'src_'.
330: $currentResourceID}));
331:
332: $cache->{$currentResourceID.':problem'}=$Problem;
333: if(!defined($cache->{$currentSequence.':problems'})) {
334: $cache->{$currentSequence.':problems'}=$currentResourceID;
335: } else {
336: $cache->{$currentSequence.':problems'}.=
337: ':'.$currentResourceID;
338: }
339:
340: $cache->{$currentResourceID.':source'} =
341: $hash{'src_'.$currentResourceID};
342: my $meta=$hash{'src_'.$currentResourceID};
343: # $cache->{$currentResourceID.':title'}=
344: # &Apache::lonnet::metdata($meta,'title');
345: $cache->{$currentResourceID.':title'}=
346: $hash{'title_'.$currentResourceID};
347:
348: # Get Parts for problem
349: my %beenHere;
350: foreach (split(/\,/,&Apache::lonnet::metadata($meta,'packages'))) {
351: if(/^\w+response_\d+.*/) {
352: my (undef, $partId, $responseId) = split(/_/,$_);
353: if($beenHere{'p:'.$partId} == 0) {
354: $beenHere{'p:'.$partId}++;
355: if(!defined($cache->{$currentSequence.':'.
356: $currentResourceID.':parts'})) {
357: $cache->{$currentSequence.':'.$currentResourceID.
358: ':parts'}=$partId;
359: } else {
360: $cache->{$currentSequence.':'.$currentResourceID.
361: ':parts'}.=':'.$partId;
362: }
363: }
364: if($beenHere{'r:'.$partId.':'.$responseId} == 0) {
365: $beenHere{'r:'.$partId.':'.$responseId}++;
366: if(!defined($cache->{$currentSequence.':'.
367: $currentResourceID.':'.$partId.
368: ':responseIDs'})) {
369: $cache->{$currentSequence.':'.$currentResourceID.
370: ':'.$partId.':responseIDs'}=$responseId;
371: } else {
372: $cache->{$currentSequence.':'.$currentResourceID.
373: ':'.$partId.':responseIDs'}.=':'.
374: $responseId;
375: }
376: }
377: if(/^optionresponse/ &&
378: $beenHere{'o:'.$partId.':'.$currentResourceID} == 0) {
379: $beenHere{'o:'.$partId.$currentResourceID}++;
380: if(defined($cache->{'OptionResponses'})) {
381: $cache->{'OptionResponses'}.= ':::'.
382: $currentResourceID.':'.
383: $partId.':'.$responseId;
384: } else {
385: $cache->{'OptionResponses'}= $currentResourceID.
386: ':'.$partId.':'.$responseId;
387: }
388: }
389: }
390: }
391: }
392:
393: # if resource == finish resource, then it is the end of a sequence/page
394: if($currentResourceID eq $lastResourceID) {
395: # pop off last resource of sequence
396: $currentResourceID=pop(@currentResource);
397: $lastResourceID=pop(@finishResource);
398:
399: if(defined($cache->{$currentSequence.':problems'})) {
400: # Capture sequence information here
401: $cache->{$currentSequence.':title'}=
402: $hash{'title_'.$currentResourceID};
403: $cache->{$currentSequence.':source'}=
404: $hash{'src_'.$currentResourceID};
405:
406: my $totalProblems=0;
407: foreach my $currentProblem (split(/\:/,
408: $cache->{$currentSequence.
409: ':problems'})) {
410: foreach (split(/\:/,$cache->{$currentSequence.':'.
411: $currentProblem.
412: ':parts'})) {
413: $totalProblems++;
414: }
415: }
416: my @titleLength=split(//,$cache->{$currentSequence.
417: ':title'});
418: # $extra is 3 for problems correct and 3 for space
419: # between problems correct and problem output
420: my $extra = 6;
421: if(($totalProblems + $extra) > (scalar @titleLength)) {
422: $cache->{$currentSequence.':columnWidth'}=
423: $totalProblems + $extra;
424: } else {
425: $cache->{$currentSequence.':columnWidth'}=
426: (scalar @titleLength);
427: }
428: } else {
429: # Remove sequence from list, if it contains no problems to
430: # display.
431: $cache->{'orderedSequences'}=~s/$currentSequence//;
432: $cache->{'orderedSequences'}=~s/::/:/g;
433: $cache->{'orderedSequences'}=~s/^:|:$//g;
434: }
435:
436: $currentSequence=pop(@sequences);
437: if($currentSequence eq $topLevelSequenceNumber) {
438: last;
439: }
440: }
441:
442: # MOVE!!!
443: # move to next resource
444: unless(defined($hash{'to_'.$currentResourceID})) {
445: # big problem, need to handle. Next is probably wrong
446: last;
447: }
448: my @nextResources=();
449: foreach (split(/\,/,$hash{'to_'.$currentResourceID})) {
450: push(@nextResources, $hash{'goesto_'.$_});
451: }
452: push(@currentResource, @nextResources);
453: # Set the next resource to be processed
454: $currentResourceID=pop(@currentResource);
455: }
456:
457: unless (untie(%hash)) {
458: &Apache::lonnet::logthis("<font color=blue>WARNING: ".
459: "Could not untie coursemap $fn (browse)".
460: ".</font>");
461: }
462:
463: return 'OK';
464: }
465:
466: =pod
467:
468: =item &ProcessClasslist()
469:
470: Taking the class list dumped from &DownloadClasslist(), all the
471: students and their non-class information is processed using the
472: &ProcessStudentInformation() function. A date stamp is also recorded for
473: when the data was processed.
474:
475: Takes data downloaded for a student and breaks it up into managable pieces and
476: stored in cache data. The username, domain, class related date, PID,
477: full name, and section are all processed here.
478:
479:
480: =over 4
481:
482: Input: $cache, $classlist, $courseID, $ChartDB, $c
483:
484: $cache: A hash pointer to store the data
485:
486: $classlist: The hash of data collected about a student from
487: &DownloadClasslist(). The hash contains a list of students, a pointer
488: to a hash of student information for each student, and each student's section
489: number.
490:
491: $courseID: The course ID
492:
493: $ChartDB: The name of the cache database file.
494:
495: $c: The connection class used to determine if an abort has been sent to the
496: browser
497:
498: Output: @names
499:
500: @names: An array of students whose information has been processed, and are to
501: be considered in an arbitrary order.
502:
503: =back
504:
505: =cut
506:
507: sub ProcessClasslist {
508: my ($cache,$classlist,$courseID,$c)=@_;
509: my @names=();
510:
511: $cache->{'ClasslistTimeStamp'}=$classlist->{'lastDownloadTime'};
512: if($classlist->{'UpToDate'} eq 'true') {
513: return split(/:::/,$cache->{'NamesOfStudents'});;
514: }
515:
516: foreach my $name (keys(%$classlist)) {
517: if($name =~ /\:section/ || $name =~ /\:studentInformation/ ||
518: $name eq '' || $name eq 'UpToDate' || $name eq 'lastDownloadTime') {
519: next;
520: }
521: if($c->aborted()) {
522: return ();
523: }
524: push(@names,$name);
525: my $studentInformation = $classlist->{$name.':studentInformation'},
526: my $sectionData = $classlist->{$name.':sections'},
527: my $date = $classlist->{$name},
528: my ($studentName,$studentDomain) = split(/\:/,$name);
529:
530: $cache->{$name.':username'}=$studentName;
531: $cache->{$name.':domain'}=$studentDomain;
532: if(!defined($cache->{$name.':lastDownloadTime'})) {
533: $cache->{$name.':lastDownloadTime'}='Not downloaded';
534: $cache->{$name.':updateTime'}=' Not updated';
535: }
536:
537: my ($checkForError)=keys(%$studentInformation);
538: if($checkForError =~ /^(con_lost|error|no_such_host)/i) {
539: $cache->{$name.':error'}=
540: 'Could not download student environment data.';
541: $cache->{$name.':fullname'}='';
542: $cache->{$name.':id'}='';
543: } else {
544: $cache->{$name.':fullname'}=&ProcessFullName(
545: $studentInformation->{'lastname'},
546: $studentInformation->{'generation'},
547: $studentInformation->{'firstname'},
548: $studentInformation->{'middlename'});
549: $cache->{$name.':id'}=$studentInformation->{'id'};
550: }
551:
552: my ($end, $start)=split(':',$date);
553: $courseID=~s/\_/\//g;
554: $courseID=~s/^(\w)/\/$1/;
555:
556: my $sec='';
557: foreach my $key (keys (%$sectionData)) {
558: my $value = $sectionData->{$key};
559: if ($key=~/^$courseID(?:\/)*(\w+)*\_st$/) {
560: my $tempsection=$1;
561: if($key eq $courseID.'_st') {
562: $tempsection='';
563: }
564: my ($dummy,$roleend,$rolestart)=split(/\_/,$value);
565: if($roleend eq $end && $rolestart eq $start) {
566: $sec = $tempsection;
567: last;
568: }
569: }
570: }
571:
572: my $status='Expired';
573: if(((!$end) || time < $end) && ((!$start) || (time > $start))) {
574: $status='Active';
575: }
576: $cache->{$name.':Status'}=$status;
577: $cache->{$name.':section'}=$sec;
578:
579: if($sec eq '' || !defined($sec) || $sec eq ' ') {
580: $sec = 'none';
581: }
582: if(defined($cache->{'sectionList'})) {
583: if($cache->{'sectionList'} !~ /(^$sec:|^$sec$|:$sec$|:$sec:)/) {
584: $cache->{'sectionList'} .= ':'.$sec;
585: }
586: } else {
587: $cache->{'sectionList'} = $sec;
588: }
589: }
590:
591: $cache->{'ClasslistTimestamp'}=time;
592: $cache->{'NamesOfStudents'}=join(':::',@names);
593:
594: return @names;
595: }
596:
597: =pod
598:
599: =item &ProcessStudentData()
600:
601: Takes the course data downloaded for a student in
602: &DownloadCourseInformation() and breaks it up into key value pairs
603: to be stored in the cached data. The keys are comprised of the
604: $username:$domain:$keyFromCourseDatabase. The student username:domain is
605: stored away signifying that the student's information has been downloaded and
606: can be reused from cached data.
607:
608: =over 4
609:
610: Input: $cache, $courseData, $name
611:
612: $cache: A hash pointer to store data
613:
614: $courseData: A hash pointer that points to the course data downloaded for a
615: student.
616:
617: $name: username:domain
618:
619: Output: None
620:
621: *NOTE: There is no output, but an error message is stored away in the cache
622: data. This is checked in &FormatStudentData(). The key username:domain:error
623: will only exist if an error occured. The error is an error from
624: &DownloadCourseInformation().
625:
626: =back
627:
628: =cut
629:
630: sub ProcessStudentData {
631: my ($cache,$courseData,$name)=@_;
632:
633: if($courseData->{'UpToDate'} eq 'true') {
634: $cache->{$name.':lastDownloadTime'}=$courseData->{'lastDownloadTime'};
635: if($courseData->{'lastDownloadTime'} eq 'Not downloaded') {
636: $cache->{$name.':updateTime'} = ' Not updated';
637: } else {
638: $cache->{$name.':updateTime'}=
639: localtime($courseData->{'lastDownloadTime'});
640: }
641: return;
642: }
643:
644: my @courseKeys = keys(%$courseData);
645:
646: foreach (@courseKeys) {
647: if(/^(con_lost|error|no_such_host)/i) {
648: $cache->{$name.':error'}='Could not download course data.';
649: return;
650: }
651: }
652:
653: $cache->{$name.':lastDownloadTime'}=$courseData->{'lastDownloadTime'};
654: if($courseData->{'lastDownloadTime'} eq 'Not downloaded') {
655: $cache->{$name.':updateTime'} = ' Not updated';
656: } else {
657: $cache->{$name.':updateTime'}=
658: localtime($courseData->{'lastDownloadTime'});
659: }
660: foreach (@courseKeys) {
661: $cache->{$name.':'.$_}=$courseData->{$_};
662: }
663:
664: return;
665: }
666:
667: sub LoadDiscussion {
668: my ( $courseID)=@_;
669: my %Discuss=();
670: my %contrib=&Apache::lonnet::dump(
671: $courseID,
672: $ENV{'course.'.$courseID.'.domain'},
673: $ENV{'course.'.$courseID.'.num'});
674:
675: #my %contrib=&DownloadCourseInformation($name, $courseID, 0);
676:
677: foreach my $temp(keys %contrib) {
678: if ($temp=~/^version/) {
679: my $ver=$contrib{$temp};
680: my ($dummy,$prb)=split(':',$temp);
681: for (my $idx=1; $idx<=$ver; $idx++ ) {
682: my $name=$contrib{"$idx:$prb:sendername"};
683: $Discuss{"$name:$prb"}=$idx;
684: }
685: }
686: }
687:
688: return \%Discuss;
689: }
690:
691: # ----- END PROCESSING FUNCTIONS ---------------------------------------
692:
693: =pod
694:
695: =head1 HELPER FUNCTIONS
696:
697: These are just a couple of functions do various odd and end
698: jobs.
699:
700: =cut
701:
702: # ----- HELPER FUNCTIONS -----------------------------------------------
703:
704: =pod
705:
706: =item &ProcessFullName()
707:
708: Takes lastname, generation, firstname, and middlename (or some partial
709: set of this data) and returns the full name version as a string. Format
710: is Lastname generation, firstname middlename or a subset of this.
711:
712: =cut
713:
714: sub ProcessFullName {
715: my ($lastname, $generation, $firstname, $middlename)=@_;
716: my $Str = '';
717:
718: if($lastname ne '') {
719: $Str .= $lastname.' ';
720: if($generation ne '') {
721: $Str .= $generation;
722: } else {
723: chop($Str);
724: }
725: $Str .= ', ';
726: if($firstname ne '') {
727: $Str .= $firstname.' ';
728: }
729: if($middlename ne '') {
730: $Str .= $middlename;
731: } else {
732: chop($Str);
733: if($firstname eq '') {
734: chop($Str);
735: }
736: }
737: } else {
738: if($firstname ne '') {
739: $Str .= $firstname.' ';
740: }
741: if($middlename ne '') {
742: $Str .= $middlename.' ';
743: }
744: if($generation ne '') {
745: $Str .= $generation;
746: } else {
747: chop($Str);
748: }
749: }
750:
751: return $Str;
752: }
753:
754: =pod
755:
756: =item &TestCacheData()
757:
758: Determine if the cache database can be accessed with a tie. It waits up to
759: ten seconds before returning failure. This function exists to help with
760: the problems with stopping the data download. When an abort occurs and the
761: user quickly presses a form button and httpd child is created. This
762: child needs to wait for the other to finish (hopefully within ten seconds).
763:
764: =over 4
765:
766: Input: $ChartDB
767:
768: $ChartDB: The name of the cache database to be opened
769:
770: Output: -1, 0, 1
771:
772: -1: Couldn't tie database
773: 0: Use cached data
774: 1: New cache database created, use that.
775:
776: =back
777:
778: =cut
779:
780: sub TestCacheData {
781: my ($ChartDB,$isRecalculate,$totalDelay)=@_;
782: my $isCached=-1;
783: my %testData;
784: my $tieTries=0;
785:
786: if(!defined($totalDelay)) {
787: $totalDelay = 10;
788: }
789:
790: if ((-e "$ChartDB") && (!$isRecalculate)) {
791: $isCached = 1;
792: } else {
793: $isCached = 0;
794: }
795:
796: while($tieTries < $totalDelay) {
797: my $result=0;
798: if($isCached) {
799: $result=tie(%testData,'GDBM_File',$ChartDB,&GDBM_READER,0640);
800: } else {
801: $result=tie(%testData,'GDBM_File',$ChartDB,&GDBM_NEWDB,0640);
802: }
803: if($result) {
804: last;
805: }
806: $tieTries++;
807: sleep 1;
808: }
809: if($tieTries >= $totalDelay) {
810: return -1;
811: }
812:
813: untie(%testData);
814:
815: return $isCached;
816: }
817:
818: sub GetFileTimestamp {
819: my ($studentDomain,$studentName,$filename,$root)=@_;
820: $studentDomain=~s/\W//g;
821: $studentName=~s/\W//g;
822: my $subdir=$studentName.'__';
823: $subdir =~ s/(.)(.)(.).*/$1\/$2\/$3/;
824: my $proname="$studentDomain/$subdir/$studentName";
825: $proname .= '/'.$filename;
826: my @dir = &Apache::lonnet::dirlist($proname, $studentDomain, $studentName,
827: $root);
828: my $fileStat = $dir[0];
829: my @stats = split('&', $fileStat);
830: if(@stats) {
831: return $stats[9];
832: } else {
833: return -1;
834: }
835: }
836:
837: # ----- END HELPER FUNCTIONS --------------------------------------------
838:
839: 1;
840: __END__
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