--- loncom/LONCAPA.pm 2008/11/17 13:22:01 1.25 +++ loncom/LONCAPA.pm 2019/08/25 22:29:29 1.35.2.2 @@ -1,7 +1,7 @@ # The LearningOnline Network # Base routines # -# $Id: LONCAPA.pm,v 1.25 2008/11/17 13:22:01 jms Exp $ +# $Id: LONCAPA.pm,v 1.35.2.2 2019/08/25 22:29:29 raeburn Exp $ # # Copyright Michigan State University Board of Trustees # @@ -27,41 +27,7 @@ # ### -=head1 NAME - -Apache::LONCAPA - -LONCAPA - Basic routines - -=head1 SYNOPSIS - -Generally useful routines - -=head1 EXPORTED SUBROUTINES - -=over 4 - -=item * - -escape() : unpack non-word characters into CGI-compatible hex codes -=item * - -unescape() : pack CGI-compatible hex codes into actual non-word ASCII character - -=item * - -add_get_param() : - 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 & - as needed - -=back - -=cut package LONCAPA; @@ -71,13 +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 $match_not_handle); @@ -86,28 +70,102 @@ require Exporter; our @ISA = qw (Exporter); our @EXPORT = qw(&add_get_param &escape &unescape &tie_domain_hash &untie_domain_hash &tie_user_hash - &untie_user_hash &propath); + &untie_user_hash &propath &tie_course); our @EXPORT_OK = qw($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; +# +# 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 + # + + +} + +# Return a string that is the path in which loncapa puts temp files: + +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 $distro; +} + +# Return the default password length. Can be overridden in a domain +# by specifying a larger value (integer) in the domain configuration. -# Inputs are a url, and a hash ref of -# form name => value pairs -# takes care of properly adding the form name elements and values to the -# the url doing proper escaping of the values and joining with ? or & as -# needed +sub passwd_min { + return 7; +} + +#---------------------------------------------------------------------- +# +# some of these subs need a bit of documentation sub add_get_param { my ($url,$form_data) = @_; @@ -141,8 +199,16 @@ 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; @@ -160,6 +226,7 @@ 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) = @_; @@ -192,6 +259,47 @@ 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 { @@ -202,35 +310,7 @@ sub propath { $subdir =~ s/(.)(.)(.).*/$1\/$2\/$3/; my $proname="$perlvar{'lonUsersDir'}/$udom/$subdir/$uname"; return $proname; -} - - -#--------------------------------------------------------------- - -=pod - -=item tie_domain_hash() - -Manipulation of hash based databases (factoring out common code -for later use as we refactor. - - Ties a domain level resource file to a hash. - If requested a history entry is created in the associated hist file. - - Parameters: - domain - Name of the domain in which the resource file lives. - namespace - Name of the hash within that domain. - how - How to tie the hash (e.g. GDBM_WRCREAT()). - loghead - Optional parameter, if present a log entry is created - in the associated history file and this is the first part - of that entry. - logtail - Goes along with loghead, The actual logentry is of the - form $loghead::logtail. -Returns: - Reference to a hash bound to the db file or alternatively undef - if the tie failed. - -=cut +} sub tie_domain_hash { my ($domain,$namespace,$how,$loghead,$logtail) = @_; @@ -251,29 +331,6 @@ sub untie_domain_hash { return &_locking_hash_untie(@_); } -=pod - -=item tie_user_hash() - - Ties a user's resource file to a hash. - If necessary, an appropriate history - log file entry is made as well. - This sub factors out common code from the subs that manipulate - the various gdbm files that keep keyword value pairs. -Parameters: - domain - Name of the domain the user is in. - user - Name of the 'current user'. - namespace - Namespace representing the file to tie. - how - What the tie is done to (e.g. GDBM_WRCREAT(). - loghead - Optional first part of log entry if there may be a - history file. - what - Optional tail of log entry if there may be a history - file. -Returns: - hash to which the database is tied. It's up to the caller to untie. - undef if the has could not be tied. - -=cut sub tie_user_hash { my ($domain,$user,$namespace,$how,$loghead,$what) = @_; @@ -289,14 +346,6 @@ sub untie_user_hash { return &_locking_hash_untie(@_); } -=pod - -=item locking_hash_tie() - -routines if you just have a filename -return tied hashref or undef - -=cut sub locking_hash_tie { my ($filename,$how)=@_; @@ -462,6 +511,7 @@ sub _do_hash_untie { } } + BEGIN { %perlvar=%{&LONCAPA::Configuration::read_conf('loncapa.conf')}; } @@ -470,4 +520,143 @@ BEGIN { __END__ +=pod + +=head1 NAME + +Apache::LONCAPA + +LONCAPA - Basic routines + +=head1 SYNOPSIS + +Generally useful routines + +=head1 EXPORTED SUBROUTINES + +=over + +=item escape() + +unpack non-word characters into CGI-compatible hex codes + +=item unescape() + + 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 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() + +=item propath() + +=item untie_domain_hash() + +=item tie_domain_hash() + +Manipulation of hash based databases (factoring out common code +for later use as we refactor. + + Ties a domain level resource file to a hash. + If requested a history entry is created in the associated hist file. + + Parameters: + domain - Name of the domain in which the resource file lives. + namespace - Name of the hash within that domain. + how - How to tie the hash (e.g. GDBM_WRCREAT()). + loghead - Optional parameter, if present a log entry is created + in the associated history file and this is the first part + of that entry. + logtail - Goes along with loghead, The actual logentry is of the + form $loghead::logtail. +Returns: + Reference to a hash bound to the db file or alternatively undef + if the tie failed. + +=item tie_user_hash() + + Ties a user's resource file to a hash. + If necessary, an appropriate history + log file entry is made as well. + This sub factors out common code from the subs that manipulate + the various gdbm files that keep keyword value pairs. +Parameters: + domain - Name of the domain the user is in. + user - Name of the 'current user'. + namespace - Namespace representing the file to tie. + how - What the tie is done to (e.g. GDBM_WRCREAT(). + loghead - Optional first part of log entry if there may be a + history file. + what - Optional tail of log entry if there may be a history + file. +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 + +=item locking_hash_untie() + +=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() + +=back + +=cut