--- loncom/LONCAPA.pm 2008/11/20 15:19:33 1.27
+++ loncom/LONCAPA.pm 2019/02/15 22:01:23 1.35.2.1
@@ -1,7 +1,7 @@
# The LearningOnline Network
# Base routines
#
-# $Id: LONCAPA.pm,v 1.27 2008/11/20 15:19:33 jms Exp $
+# $Id: LONCAPA.pm,v 1.35.2.1 2019/02/15 22:01:23 raeburn Exp $
#
# Copyright Michigan State University Board of Trustees
#
@@ -37,13 +37,31 @@ use LONCAPA::Configuration;
use Fcntl qw(:flock);
use GDBM_File;
use POSIX;
+#use Apache::lonnet;
my $loncapa_max_wait_time = 13;
+#--------------------------------------------------------------------------
+#
+# The constant definnitions below probably should really be in
+# a configuration file somewhere (loncapa.conf?) and loaded so that they can be
+# modified without requring source code changes:
+#
+# COURSE_CACHE_TIME - Number of minutes after which an unaccessed
+# course.db or course_param.db file is considered
+# to be a stale cache of this info.
+#
+# LONCAPA_TEMPDIR - Place loncapa puts temporary files
+#
+
+my $COURSE_CACHE_TIME = 60; # minutes course cache file is considered valid.
+my $LONCAPA_TEMPDIR = '/tmp/'; # relative to configuration{'lonTabDir'}.
+
use vars qw($match_domain $match_not_domain
$match_username $match_not_username
$match_courseid $match_not_courseid
+ $match_community
$match_name
$match_lonid
$match_handle $match_not_handle);
@@ -52,35 +70,95 @@ require Exporter;
our @ISA = qw (Exporter);
our @EXPORT = qw(&add_get_param &escape &unescape
&tie_domain_hash &untie_domain_hash &tie_user_hash
- &untie_user_hash &propath);
+ &untie_user_hash &propath &tie_course);
our @EXPORT_OK = qw($match_domain $match_not_domain
$match_username $match_not_username
$match_courseid $match_not_courseid
+ $match_community
$match_name
$match_lonid
- $match_handle $match_not_handle);
+ $match_handle $match_not_handle &tie_course);
our %EXPORT_TAGS = ( 'match' =>[qw($match_domain $match_not_domain
$match_username $match_not_username
$match_courseid $match_not_courseid
+ $match_community
$match_name
$match_lonid
$match_handle $match_not_handle)],);
my %perlvar;
-=pod
+#
+# If necessary fetch and tie a user's image of the course hash
+# to the specified hash
+# Parameters:
+# domain - User's domain
+# user - Name of user.
+# course - Course number.
+# cdom - Domain that is home to the course
+# hash - reference to the has to tie.
+#
+# Side effects:
+# a gdbm file and it's associated lock file will be created in the
+# tmp directory tree.
+#
+# Returns:
+# 0 - failure.
+# 1 - success.
+#
+# Note:
+# It's possible the required user's db file is already present in the tempdir.
+# in that case a decision must be made about whether or not to just tie to it
+# or to fetch it again. Remember this sub could be called in the context of a user
+# other than the one whose data are being fetched. We don't know if that user already
+# has a live session on this server. What we'll do is only re-fetch if the hash atime.
+# is older than COURSE_CACHE_TIME...that is if it's been accessed relatively recently
+# where COURSE_CACHE_TIME defines the caching time.
+#
+# The database files this function creates are of the form:
+# $user@$domain_$course@$cdom.{db,lock}
+# This differs from the prior filenames. Therefore if a module does its own
+# caching (That's a coding no-no) and does not use this centralized sub,
+# multiple cache files for the same course/user will be created.
+#
+sub tie_course {
+ my ($domain, $user, $course, $cdom, $hash) = @_;
+
+ #
+ # See if we need to re-fetch the course data
+ #
-=head2 NOTE:
+
+}
-add_get_param()
+# Return a string that is the path in which loncapa puts temp files:
-Inputs are a url, and a hash ref of
-form name => value pairs
-takes care of properly adding the form name elements and values to the
-the url doing proper escaping of the values and joining with ? or & as
-needed
+sub tempdir {
+ my $result = $perlvar{'lonDaemons'}.$LONCAPA_TEMPDIR; # to allow debugging.
+ return $result;
+}
+
+# Return the default engine to use to render content of tags unless
+# a domain, course, or user specific value exists.
+
+sub texengine {
+ return 'tth';
+}
+
+# Return the Linux distro where this LON-CAPA instance is running
+
+sub distro {
+ my $distro;
+ if (open(PIPE,"/home/httpd/perl/distprobe |")) {
+ $distro = ;
+ close(PIPE);
+ }
+ return $distro;
+}
-=cut
+#----------------------------------------------------------------------
+#
+# some of these subs need a bit of documentation
sub add_get_param {
my ($url,$form_data) = @_;
@@ -114,8 +192,16 @@ sub unescape {
return $str;
}
-$match_domain = $LONCAPA::domain_re = qr{[\w\-.]+};
-$match_not_domain = $LONCAPA::not_domain_re = qr{[^\w\-.]+};
+$LONCAPA::assess_re = qr{\.(problem|exam|quiz|assess|survey|form|library|task)$};
+$LONCAPA::assess_page_re = qr{\.(problem|exam|quiz|assess|survey|form|library|task|page)$};
+$LONCAPA::assess_page_seq_re = qr{\.(problem|exam|quiz|assess|survey|form|library|task|sequence|page)$};
+$LONCAPA::parse_re = qr{\.(problem|exam|quiz|assess|survey|form|library|page|xml|html|htm|xhtml|xhtm)$};
+$LONCAPA::parse_page_re = qr{\.(problem|exam|quiz|assess|survey|form|library|page|xml|html|htm|xhtml|xhtm|page)$};
+$LONCAPA::parse_page_sty_re = qr{\.(problem|exam|quiz|assess|survey|form|library|page|xml|html|htm|xhtml|xhtm|page|sty)$};
+
+
+$match_domain = $LONCAPA::domain_re = qr{[[:alnum:]\-.]+};
+$match_not_domain = $LONCAPA::not_domain_re = qr{[^[:alnum:]\-.]+};
sub clean_domain {
my ($domain) = @_;
$domain =~ s/$match_not_domain//g;
@@ -133,6 +219,7 @@ sub clean_username {
$match_courseid = $LONCAPA::courseid_re = qr{\d[\w\-.]+};
+$match_community =$LONCAPA::community_re = qr{0[\w\-.]+};
$match_not_courseid = $LONCAPA::not_courseid_re = qr{[^\w\-.]+};
sub clean_courseid {
my ($courseid) = @_;
@@ -165,6 +252,47 @@ sub clean_handle {
return $handle;
}
+#
+# -- Ensure another process for same filesystem action is not running.
+# lond uses for: apachereload; loncron uses for: lciptables
+#
+
+sub try_to_lock {
+ my ($lockfile)=@_;
+ my $currentpid;
+ my $lastpid;
+ # Do not manipulate lock file as root
+ if ($>==0) {
+ return 0;
+ }
+ # Try to generate lock file.
+ # Wait 3 seconds. If same process id is in
+ # lock file, then assume lock file is stale, and
+ # go ahead. If process id's fluctuate, try
+ # for a maximum of 10 times.
+ for (0..10) {
+ if (-e $lockfile) {
+ open(LOCK,"<$lockfile");
+ $currentpid=;
+ close LOCK;
+ if ($currentpid==$lastpid) {
+ last;
+ }
+ sleep 3;
+ $lastpid=$currentpid;
+ } else {
+ last;
+ }
+ if ($_==10) {
+ return 0;
+ }
+ }
+ open(LOCK,">$lockfile");
+ print LOCK $$;
+ close LOCK;
+ return 1;
+}
+
# -------------------------------------------- Return path to profile directory
sub propath {
@@ -175,8 +303,7 @@ sub propath {
$subdir =~ s/(.)(.)(.).*/$1\/$2\/$3/;
my $proname="$perlvar{'lonUsersDir'}/$udom/$subdir/$uname";
return $proname;
-}
-
+}
sub tie_domain_hash {
my ($domain,$namespace,$how,$loghead,$logtail) = @_;
@@ -377,6 +504,7 @@ sub _do_hash_untie {
}
}
+
BEGIN {
%perlvar=%{&LONCAPA::Configuration::read_conf('loncapa.conf')};
}
@@ -385,6 +513,7 @@ BEGIN {
__END__
+=pod
=head1 NAME
@@ -409,12 +538,14 @@ unpack non-word characters into CGI-comp
pack CGI-compatible hex codes into actual non-word ASCII character
=item add_get_param()
+
+Append escaped form elements (name=value etc.) to a url.
Inputs: url (with or without exit GET from parameters), hash ref of
form name => value pairs
- Return: url with properly added the form name elements and values to the
- the url doing proper escaping of the values and joining with ? or &
+ Return: url with form name elements and values appended to the
+ the url, doing proper escaping of the values and joining with ? or &
as needed
=item clean_handle()
@@ -464,6 +595,37 @@ Returns:
hash to which the database is tied. It's up to the caller to untie.
undef if the has could not be tied.
+=item tie_course
+
+Caches the course database into the temp directory in the context of a specific
+user and ties it to a hash.
+Parameters:
+ domain - Domain the user is in.
+ user - Username of the user.
+ course - Course specification
+ cdom - The course domain.
+ hash - Reference to the hash to tie.
+
+Returns:
+ 1 - Success
+ 0 - Failure.
+
+=item tie_course_params
+
+Caches the course parameter database into the temp directory in the context
+of a specific user and ties it to a hash.
+Parameters:
+ domain - Domain the user is in.
+ user - Username of the user.
+ course - course specification.
+ cdom - The course domain.
+ hash - reference to the hash to tie.
+
+Returns:
+ 1 - Success.
+ 0 - Failure./
+
+
=item locking_hash_tie()
routines if you just have a filename return tied hashref or undef
@@ -472,8 +634,17 @@ routines if you just have a filename ret
=item db_filename_parts()
+=back
+
+=item tempdir()
+
+Returns the file system path to the place loncapa temporary files should be placed/found.
+
+
=head1 INTERNAL SUBROUTINES
+=over
+
=item _do_hash_tie()
=item _do_hash_untie()