--- rat/lonuserstate.pm 2011/04/21 13:28:50 1.137
+++ rat/lonuserstate.pm 2011/08/04 10:57:26 1.139
@@ -1,7 +1,7 @@
# The LearningOnline Network with CAPA
# Construct and maintain state and binary representation of course for user
#
-# $Id: lonuserstate.pm,v 1.137 2011/04/21 13:28:50 raeburn Exp $
+# $Id: lonuserstate.pm,v 1.139 2011/08/04 10:57:26 foxr Exp $
#
# Copyright Michigan State University Board of Trustees
#
@@ -43,11 +43,13 @@ use Opcode;
use Apache::lonenc;
use Fcntl qw(:flock);
use LONCAPA;
+use File::Basename;
+
# ---------------------------------------------------- Globals for this package
-my $pc; # Package counter
+my $pc; # Package counter is this what 'Guts' calls the map counter?
my %hash; # The big tied hash
my %parmhash;# The hash with the parameters
my @cond; # Array with all of the conditions
@@ -68,6 +70,21 @@ sub versionerror {
$uri,$usedversion,$unusedversion).' ';
}
+# Removes the version number from a URI and returns the resulting
+# URI (e.g. mumbly.version.stuff => mumbly.stuff).
+#
+# If the URI has not been seen with a versio before the
+# hash{'version_'.resultingURI} is set to the version number.
+# If the URI has been seen and the version does not match and error
+# is added to the error string.
+#
+# Parameters:
+# URI potentially with a version.
+# Returns:
+# URI with the version cut out.
+# See above for side effects.
+#
+
sub versiontrack {
my $uri=shift;
if ($uri=~/\.(\d+)\.\w+$/) {
@@ -112,20 +129,30 @@ sub processversionfile {
}
}
-# --------------------------------------------------------- Loads map from disk
+# --------------------------------------------------------- Loads from disk
sub loadmap {
my ($uri,$parent_rid)=@_;
+
+ # Is the map already included?
+
if ($hash{'map_pc_'.$uri}) {
$errtext.='
'.
&mt('Multiple use of sequence/page [_1]! The course will not function properly.',''.$uri.'').
'
';
return;
}
+ # Register the resource in it's map_pc_ [for the URL]
+ # map_id.nnn is the nesting level -> to the URI.
+
$pc++;
my $lpc=$pc;
$hash{'map_pc_'.$uri}=$lpc;
$hash{'map_id_'.$lpc}=$uri;
+
+ # If the parent is of the form n.m hang this map underneath it in the
+ # map hierarchy.
+
if ($parent_rid =~ /^(\d+)\.\d+$/) {
my $parent_pc = $1;
if (defined($hash{'map_hierarchy_'.$parent_pc})) {
@@ -136,17 +163,21 @@ sub loadmap {
}
}
-# Determine and check filename
+# Determine and check filename of the sequence we need to read:
+
my $fn=&Apache::lonnet::filelocation('',&putinversion($uri));
my $ispage=($fn=~/\.page$/);
- unless (($fn=~/\.sequence$/) ||
- ($fn=~/\.page$/)) {
+ # We can only nest sequences or pages. Anything else is an illegal nest.
+
+ unless (($fn=~/\.sequence$/) || $ispage) {
$errtext.=&mt(" Invalid map: [_1]",$fn);
return;
}
+ # Read the XML that constitutes the file.
+
my $instr=&Apache::lonnet::getfile($fn);
if ($instr eq -1) {
@@ -154,18 +185,29 @@ sub loadmap {
return;
}
-# Successfully got file, parse it
+ # Successfully got file, parse it
+
+ # parse for parameter processing.
+ # Note that these are tags
+ # so we only care about 'S' (tag start) nodes.
+
my $parser = HTML::TokeParser->new(\$instr);
$parser->attr_encoded(1);
+
# first get all parameters
+
+
while (my $token = $parser->get_token) {
next if ($token->[0] ne 'S');
if ($token->[1] eq 'param') {
&parse_param($token,$lpc);
}
}
- #reset parser
+
+ # Get set to take another pass through the XML:
+ # for resources and links.
+
$parser = HTML::TokeParser->new(\$instr);
$parser->attr_encoded(1);
@@ -177,27 +219,54 @@ sub loadmap {
my $randomize = ($randomorder{$parent_rid} =~ /^yes$/i);
+ # Parse the resources, link and condition tags.
+ # Note that if randomorder or random select is chosen the links and
+ # conditions are meaningless but are determined by the randomization.
+ # This is handled in the next chunk of code.
+
my @map_ids;
while (my $token = $parser->get_token) {
next if ($token->[0] ne 'S');
+
+ # Resource
+
if ($token->[1] eq 'resource') {
- push(@map_ids,&parse_resource($token,$lpc,$ispage,$uri));
+ my $resource_id = &parse_resource($token,$lpc,$ispage,$uri);
+ if (defined $resource_id) {
+ push(@map_ids, $resource_id);
+ }
+
+ # Link
+
} elsif ($token->[1] eq 'link' && !$randomize) {
-# ----------------------------------------------------------------------- Links
&make_link(++$linkpc,$lpc,$token->[2]->{'to'},
$token->[2]->{'from'},
- $token->[2]->{'condition'});
+ $token->[2]->{'condition'}); # note ..condition may be undefined.
+
+ # condition
+
} elsif ($token->[1] eq 'condition' && !$randomize) {
&parse_condition($token,$lpc);
}
}
+
+ # Handle randomization and random selection
+
if ($randomize) {
if (!$env{'request.role.adv'}) {
my $seed;
+
+ # In the advanced role, the map's random seed
+ # parameter is used as the basis for computing the
+ # seed ... if it has been specified:
+
if (defined($randompickseed{$parent_rid})) {
$seed = $randompickseed{$parent_rid};
} else {
+
+ # Otherwise the parent's fully encoded symb is used.
+
my ($mapid,$resid)=split(/\./,$parent_rid);
my $symb=
&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
@@ -205,16 +274,27 @@ sub loadmap {
$seed = $symb;
}
-
+
+ # TODO: Here for sure we need to pass along the username/domain
+ # so that we can impersonate users in lonprintout e.g.
+
my $rndseed=&Apache::lonnet::rndseed($seed);
&Apache::lonnet::setup_random_from_rndseed($rndseed);
- @map_ids=&Math::Random::random_permutation(@map_ids);
+ @map_ids=&math::Random::random_permutation(@map_ids); # randomorder.
}
+
+
my $from = shift(@map_ids);
my $from_rid = $lpc.'.'.$from;
$hash{'map_start_'.$uri} = $from_rid;
$hash{'type_'.$from_rid}='start';
+ # Create links to reflect this random ordering.
+ # BUG? If there are conditions, this invalidates them? Then again
+ # with randompick there's no gaurentee the resources required for the
+ # conditinos to work will be selected into the map.
+ # so randompick is inconsistent with a map that has conditions?
+
while (my $to = shift(@map_ids)) {
&make_link(++$linkpc,$lpc,$to,$from);
my $to_rid = $lpc.'.'.$to;
@@ -229,8 +309,10 @@ sub loadmap {
$parser = HTML::TokeParser->new(\$instr);
$parser->attr_encoded(1);
+
# last parse out the mapalias params so as to ignore anything
# refering to non-existant resources
+
while (my $token = $parser->get_token) {
next if ($token->[0] ne 'S');
if ($token->[1] eq 'param') {
@@ -241,25 +323,89 @@ sub loadmap {
# -------------------------------------------------------------------- Resource
+#
+# Parses a resource tag to produce the value to push into the
+# map_ids array.
+#
+#
+# Information about the actual type of resource is provided by the file extension
+# of the uri (e.g. .problem, .sequence etc. etc.).
+#
+# Parameters:
+# $token - A token from HTML::TokeParser
+# This is an array that describes the most recently parsed HTML item.
+# $lpc - Map nesting level (?)
+# $ispage - True if this resource is encapsulated in a .page (assembled resourcde).
+# $uri - URI of the enclosing resource.
+# Returns:
+# Value of the id attribute of the tag.
+#
+# Note:
+# The token is an array that contains the following elements:
+# [0] => 'S' indicating this is a start token
+# [1] => 'resource' indicating this tag is a tag.
+# [2] => Hash of attribute =>value pairs.
+# [3] => @(keys [2]).
+# [4] => unused.
+#
+# The attributes of the resourcde tag include:
+#
+# id - The resource id.
+# src - The URI of the resource.
+# type - The resource type (e.g. start and finish).
+# title - The resource title.
+
+
sub parse_resource {
my ($token,$lpc,$ispage,$uri) = @_;
- if ($token->[2]->{'type'} eq 'zombie') { next; }
- my $rid=$lpc.'.'.$token->[2]->{'id'};
+
+ # I refuse to countenance code like this that has
+ # such a dirty side effect (and forcing this sub to be called within a loop).
+ #
+ # if ($token->[2]->{'type'} eq 'zombie') { next; }
+ #
+ # The original code both returns _and_ skips to the next pass of the >caller's<
+ # loop, that's just dirty.
+ #
+
+ # Zombie resources don't produce anything useful.
+
+ if ($token->[2]->{'type'} eq 'zombie') {
+ return undef;
+ }
+
+ my $rid=$lpc.'.'.$token->[2]->{'id'}; # Resource id in hash is levelcounter.id-in-xml.
+
+ # Save the hash element type and title:
$hash{'kind_'.$rid}='res';
$hash{'title_'.$rid}=$token->[2]->{'title'};
+
+ # Get the version free URI for the resource.
+ # If a 'version' attribute was supplied, and this resource's version
+ # information has not yet been stored, store it.
+ #
+
my $turi=&versiontrack($token->[2]->{'src'});
if ($token->[2]->{'version'}) {
unless ($hash{'version_'.$turi}) {
$hash{'version_'.$turi}=$1;
}
}
+ # Pull out the title and do entity substitution on &colon
+ # Q: Why no other entity substitutions?
+
my $title=$token->[2]->{'title'};
$title=~s/\&colon\;/\:/gs;
-# my $symb=&Apache::lonnet::encode_symb($uri,
-# $token->[2]->{'id'},
-# $turi);
-# &Apache::lonnet::do_cache_new('title',$symb,$title);
+
+
+
+ # I think the point of all this code is to construct a final
+ # URI that apache and its rewrite rules can use to
+ # fetch the resource. Thi s sonly necessary if the resource
+ # is not a page. If the resource is a page then it must be
+ # assembled (at fetch time?).
+
unless ($ispage) {
$turi=~/\.(\w+)$/;
my $embstyle=&Apache::loncommon::fileembstyle($1);
@@ -286,7 +432,10 @@ sub parse_resource {
}
}
}
-# Store reverse lookup, remove query string
+ # Store reverse lookup, remove query string resource 'ids'_uri => resource id.
+ # If the URI appears more than one time in the sequence, it's resourcde
+ # id's are constructed as a comma spearated list.
+
my $idsuri=$turi;
$idsuri=~s/\?.+$//;
if (defined($hash{'ids_'.$idsuri})) {
@@ -295,17 +444,37 @@ sub parse_resource {
$hash{'ids_'.$idsuri}=''.$rid;
}
+
+
if ($turi=~/\/(syllabus|aboutme|navmaps|smppg|bulletinboard|viewclasslist)$/) {
$turi.='?register=1';
}
+
+ # resource id lookup: 'src'_resourc-di => URI decorated with a query
+ # parameter as above if necessary due to the resource type.
+
$hash{'src_'.$rid}=$turi;
+
+ # Mark the external-ness of the resource:
if ($token->[2]->{'external'} eq 'true') {
$hash{'ext_'.$rid}='true:';
} else {
$hash{'ext_'.$rid}='false:';
}
+
+ # If the resource is a start/finish resource set those
+ # entries in the has so that navigation knows where everything starts.
+ # TODO? If there is a malformed sequence that has no start or no finish
+ # resource, should this be detected and errors thrown? How would such a
+ # resource come into being other than being manually constructed by a person
+ # and then uploaded? Could that happen if an author decided a sequence was almost
+ # right edited it by hand and then reuploaded it to 'fix it' but accidently cut the
+ # start or finish resources?
+ #
+ # All resourcess also get a type_id => (start | finish | normal) hash entr.
+ #
if ($token->[2]->{'type'}) {
$hash{'type_'.$rid}=$token->[2]->{'type'};
if ($token->[2]->{'type'} eq 'start') {
@@ -317,6 +486,12 @@ sub parse_resource {
} else {
$hash{'type_'.$rid}='normal';
}
+
+ # Sequences end pages are constructed entities. They require that the
+ # map that defines _them_ be loaded as well into the hash...with this resourcde
+ # as the base of the nesting.
+ # Resources like that are also marked with is_map_id => 1 entries.
+ #
if (($turi=~/\.sequence$/) ||
($turi=~/\.page$/)) {
@@ -326,22 +501,65 @@ sub parse_resource {
return $token->[2]->{'id'};
}
+#-------------------------------------------------------------------- link
+# Links define how you are allowed to move from one resource to another.
+# They are the transition edges in the directed graph that a map is.
+# This sub takes informatino from a tag and constructs the
+# navigation bits and pieces of a map. There is no requirement that the
+# resources that are linke are already defined, however clearly the map is
+# badly broken if they are not _eventually_ defined.
+#
+# Note that links can be unconditional or conditional.
+#
+# Parameters:
+# linkpc - The link counter for this level of map nesting (this is
+# reset to zero by loadmap prior to starting to process
+# links for map).
+# lpc - The map level ocounter (how deeply nested this map is in
+# the hierarchy of maps that are recursively read in.
+# to - resource id (within the XML) of the target of the edge.
+# from - resource id (within the XML) of the source of the edge.
+# condition- id of condition associated with the edge (also within the XML).
+#
+
sub make_link {
my ($linkpc,$lpc,$to,$from,$condition) = @_;
+ # Compute fully qualified ids for the link, the
+ # and from/to by prepending lpc.
+ #
+
my $linkid=$lpc.'.'.$linkpc;
my $goesto=$lpc.'.'.$to;
my $comesfrom=$lpc.'.'.$from;
my $undercond=0;
+
+ # If there is a condition, qualify it with the level counter.
+
if ($condition) {
$undercond=$lpc.'.'.$condition;
}
+ # Links are represnted by:
+ # goesto_.fuullyqualifedlinkid => fully qualified to
+ # comesfrom.fullyqualifiedlinkid => fully qualified from
+ # undercond_.fullyqualifiedlinkid => fully qualified condition id.
+
$hash{'goesto_'.$linkid}=$goesto;
$hash{'comesfrom_'.$linkid}=$comesfrom;
$hash{'undercond_'.$linkid}=$undercond;
+ # In addition:
+ # to_.fully qualified from => comma separated list of
+ # link ids with that from.
+ # Similarly:
+ # from_.fully qualified to => comma separated list of link ids`
+ # with that to.
+ # That allows us given a resource id to know all edges that go to it
+ # and leave from it.
+ #
+
if (defined($hash{'to_'.$comesfrom})) {
$hash{'to_'.$comesfrom}.=','.$linkid;
} else {
@@ -355,6 +573,54 @@ sub make_link {
}
# ------------------------------------------------------------------- Condition
+#
+# Processes tags, storing sufficient information about them
+# in the hash so that they can be evaluated and used to conditionalize
+# what is presented to the student.
+#
+# these can have the following attributes
+#
+# id = A unique identifier of the condition within the map.
+#
+# value = Is a perl script-let that, when evaluated in safe space
+# determines whether or not the condition is true.
+# Normally this takes the form of a test on an Apache::lonnet::EXT call
+# to find the value of variable associated with a resource in the
+# map identified by a mapalias.
+# Here's a fragment of XML code that illustrates this:
+#
+#
+#
+#
+#
+#
+#
+# In this fragment:
+# - The param tag establishes an alias to resource id 5 of 'mainproblem'.
+# - The resource that is the start of the map is identified.
+# - The resource tag identifies the resource associated with this tag
+# and gives it the id 5.
+# - The condition is true if the tries variable associated with mainproblem
+# is less than 2 (that is the user has had more than 2 tries).
+# The condition type is a stop condition which inhibits(?) the associated
+# link if the condition is false.
+# - The link to resource 5 from resource 1 is affected by this condition.
+#
+# type = Type of the condition. The type determines how the condition affects the
+# link associated with it and is one of
+# - 'force'
+# - 'stop'
+# anything else including not supplied..which treated as:
+# - 'normal'.
+# Presumably maps get created by the resource assembly tool and therefore
+# illegal type values won't squirm their way into the XML.
+#
+# Side effects:
+# - The kind_level-qualified-condition-id hash element is set to 'cond'.
+# - The condition text is pushed into the cond array and its element number is
+# set in the condid_level-qualified-condition-id element of the hash.
+# - The condition type is colon appneded to the cond array element for this condition.
sub parse_condition {
my ($token,$lpc) = @_;
my $rid=$lpc.'.'.$token->[2]->{'id'};
@@ -373,36 +639,77 @@ sub parse_condition {
}
# ------------------------------------------------------------------- Parameter
+# Parse a tag in the map.
+# Parmameters:
+# $token Token array for a start tag from HTML::TokeParser
+# [0] = 'S'
+# [1] = tagname ("param")
+# [2] = Hash of {attribute} = values.
+# [3] = Array of the keys in [2].
+# [4] = unused.
+# $lpc Current map nesting level.a
+#
+# Typical attributes:
+# to=n - Number of the resource the parameter applies to.
+# type=xx - Type of parameter value (e.g. string_yesno or int_pos).
+# name=xxx - Name ofr parameter (e.g. parameter_randompick or parameter_randomorder).
+# value=xxx - value of the parameter.
sub parse_param {
my ($token,$lpc) = @_;
- my $referid=$lpc.'.'.$token->[2]->{'to'};
- my $name=$token->[2]->{'name'};
+ my $referid=$lpc.'.'.$token->[2]->{'to'}; # Resource param applies to.
+ my $name=$token->[2]->{'name'}; # Name of parameter
my $part;
- if ($name=~/^parameter_(.*)_/) {
+
+
+ if ($name=~/^parameter_(.*)_/) {
$part=$1;
} else {
$part=0;
}
+
+ # Peel the parameter_ off the parameter name.
+
$name=~s/^.*_([^_]*)$/$1/;
+
+ # The value is:
+ # type.part.name.value
+
my $newparam=
&escape($token->[2]->{'type'}).':'.
&escape($part.'.'.$name).'='.
&escape($token->[2]->{'value'});
+
+ # The hash key is param_resourceid.
+ # Multiple parameters for a single resource are & separated in the hash.
+
+
if (defined($hash{'param_'.$referid})) {
$hash{'param_'.$referid}.='&'.$newparam;
} else {
$hash{'param_'.$referid}=''.$newparam;
}
- if ($token->[2]->{'name'}=~/^parameter_(0_)*randompick$/) {
+ #
+ # These parameters have to do with randomly selecting
+ # resources, therefore a separate hash is also created to
+ # make it easy to locate them when actually computing the resource set later on
+ # See the code conditionalized by ($randomize) in loadmap().
+
+ if ($token->[2]->{'name'}=~/^parameter_(0_)*randompick$/) { # Random selection turned on
$randompick{$referid}=$token->[2]->{'value'};
}
- if ($token->[2]->{'name'}=~/^parameter_(0_)*randompickseed$/) {
+ if ($token->[2]->{'name'}=~/^parameter_(0_)*randompickseed$/) { # Randomseed provided.
$randompickseed{$referid}=$token->[2]->{'value'};
}
- if ($token->[2]->{'name'}=~/^parameter_(0_)*randomorder$/) {
+ if ($token->[2]->{'name'}=~/^parameter_(0_)*randomorder$/) { # Random order turned on.
$randomorder{$referid}=$token->[2]->{'value'};
}
+
+ # These parameters have to do with how the URLs of resources are presented to
+ # course members(?). encrypturl presents encypted url's while
+ # hiddenresource hides the URL.
+ #
+
if ($token->[2]->{'name'}=~/^parameter_(0_)*encrypturl$/) {
if ($token->[2]->{'value'}=~/^yes$/i) {
$encurl{$referid}=1;
@@ -657,7 +964,11 @@ sub hiddenurls {
sub readmap {
my $short=shift;
$short=~s/^\///;
- my %cenv=&Apache::lonnet::coursedescription($short,{'freshen_cache'=>1});
+
+ # TODO: Hidden dependency on current user:
+
+ my %cenv=&Apache::lonnet::coursedescription($short,{'freshen_cache'=>1});
+
my $fn=$cenv{'fn'};
my $uri;
$short=~s/\//\_/g;
@@ -669,27 +980,40 @@ sub readmap {
@cond=('true:normal');
unless (open(LOCKFILE,">$fn.db.lock")) {
+ #
+ # Most likely a permissions problem on the lockfile or its directory.
+ #
$errtext.=' '.&mt('Map not loaded - Lock file could not be opened when reading map:').' '.$fn.'.';
$retfurl = '';
return ($retfurl,$errtext);
}
my $lock=0;
my $gotstate=0;
- if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
- $lock=1;
+
+ # If we can get the lock without delay any files there are idle
+ # and from some prior request. We'll kill them off and regenerate them:
+
+ if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
+ $lock=1; # Remember that we hold the lock.
&unlink_tmpfiles($fn);
}
undef %randompick;
undef %hiddenurl;
undef %encurl;
$retfrid='';
- my ($untiedhash,$untiedparmhash,$tiedhash,$tiedparmhash);
+ my ($untiedhash,$untiedparmhash,$tiedhash,$tiedparmhash); # More state flags.
+
+ # if we got the lock, regenerate course regnerate empty files and tie them.
+
if ($lock) {
if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
$tiedhash = 1;
if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
$tiedparmhash = 1;
- $gotstate = &build_tmp_hashes($uri,$fn,$short,\%cenv);
+ $gotstate = &build_tmp_hashes($uri,
+ $fn,
+ $short,
+ \%cenv); # TODO: Need to provide requested user@dom
unless ($gotstate) {
&Apache::lonnet::logthis('Failed to write statemap at first attempt '.$fn.' for '.$uri.'.');
}
@@ -705,7 +1029,10 @@ sub readmap {
'Could not untie coursemap hash '.$fn.' for '.$uri.'.');
}
}
- flock(LOCKFILE,LOCK_UN);
+ flock(LOCKFILE,LOCK_UN); # RF: this is what I don't get unless there are other
+ # unlocked places the remainder happens..seems like if we
+ # just kept the lock here the rest of the code would have
+ # been much easier?
}
unless ($lock && $tiedhash && $tiedparmhash) {
# if we are here it is likely because we are already trying to
@@ -713,6 +1040,13 @@ sub readmap {
# tie the hashes for the next 90 seconds, if we succeed forward
# them on to navmaps, if we fail, throw up the Could not init
# course screen
+ #
+ # RF: I'm not seeing the case where the ties/unties can fail in a way
+ # that can be remedied by this. Since we owned the lock seems
+ # Tie/untie failures are a result of something like a permissions problem instead?
+ #
+
+ # In any vent, undo what we did manage to do above first:
if ($lock) {
# Got the lock but not the DB files
flock(LOCKFILE,LOCK_UN);
@@ -728,15 +1062,25 @@ sub readmap {
untie(%parmhash);
}
}
+ # Log our failure:
+
&Apache::lonnet::logthis('WARNING: '.
"Could not tie coursemap $fn for $uri.");
$tiedhash = '';
$tiedparmhash = '';
my $i=0;
+
+ # Keep on retrying the lock for 90 sec until we succeed.
+
while($i<90) {
$i++;
sleep(1);
if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
+
+ # Got the lock, tie the hashes...the assumption in this code is
+ # that some other worker thread has created the db files quite recently
+ # so no load is needed:
+
$lock = 1;
if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER(),0640)) {
$tiedhash = 1;
@@ -744,6 +1088,11 @@ sub readmap {
$tiedparmhash = 1;
if (-e "$fn.state") {
$retfurl='/adm/navmaps';
+
+ # BUG BUG: Side effect!
+ # Should conditionalize on something so that we can use this
+ # to load maps for courses that are not current?
+ #
&Apache::lonnet::appenv({"request.course.id" => $short,
"request.course.fn" => $fn,
"request.course.uri" => $uri});
@@ -775,6 +1124,11 @@ sub readmap {
}
}
}
+ # I think this branch of code is all about what happens if we just did the stuff above,
+ # but found that the state file did not exist...again if we'd just held the lock
+ # would that have made this logic simpler..as generating all the files would be
+ # an atomic operation with respect to the lock.
+ #
unless ($gotstate) {
$lock = 0;
&Apache::lonnet::logthis('WARNING: '.
@@ -787,10 +1141,13 @@ sub readmap {
undef %hiddenurl;
undef %encurl;
$retfrid='';
+ #
+ # Once more through the routine of tying and loading and so on.
+ #
if ($lock) {
if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
- $gotstate = &build_tmp_hashes($uri,$fn,$short,\%cenv);
+ $gotstate = &build_tmp_hashes($uri,$fn,$short,\%cenv); # TODO: User dependent?
unless ($gotstate) {
&Apache::lonnet::logthis('WARNING: '.
'Failed to write statemap at second attempt '.$fn.' for '.$uri.'.');
@@ -814,6 +1171,8 @@ sub readmap {
flock(LOCKFILE,LOCK_UN);
$lock = 0;
} else {
+ # Failed to get the immediate lock.
+
&Apache::lonnet::logthis('WARNING: '.
'Could not obtain lock to tie coursemap hash '.$fn.'.db for '.$uri.'.');
}
@@ -821,10 +1180,13 @@ sub readmap {
close(LOCKFILE);
unless (($errtext eq '') || ($env{'request.course.uri'} =~ m{^/uploaded/})) {
&Apache::lonmsg::author_res_msg($env{'request.course.uri'},
- $errtext);
+ $errtext); # TODO: User dependent?
}
# ------------------------------------------------- Check for critical messages
+# Depends on user must parameterize this as well..or separate as this is:
+# more part of determining what someone sees on entering a course?
+
my @what=&Apache::lonnet::dump('critical',$env{'user.domain'},
$env{'user.name'});
if ($what[0]) {
@@ -835,20 +1197,39 @@ sub readmap {
return ($retfurl,$errtext);
}
+#
+# This sub is called when the course hash and the param hash have been tied and
+# their lock file is held.
+# Parameters:
+# $uri - URI that identifies the course.
+# $fn - The base path/filename of the files that make up the context
+# being built.
+# $short - Short course name.
+# $cenvref - Reference to the course environment hash returned by
+# Apache::lonnet::coursedescription
+#
+# Assumptions:
+# The globals
+# %hash, %paramhash are tied to their gdbm files and we hold the lock on them.
+#
sub build_tmp_hashes {
my ($uri,$fn,$short,$cenvref) = @_;
+
unless(ref($cenvref) eq 'HASH') {
return;
}
my %cenv = %{$cenvref};
my $gotstate = 0;
- %hash=();
+ %hash=(); # empty the global course and parameter hashes.
%parmhash=();
- $errtext='';
+ $errtext=''; # No error messages yet.
$pc=0;
&clear_mapalias_count();
&processversionfile(%cenv);
my $furi=&Apache::lonnet::clutter($uri);
+ #
+ # the map staring points.
+ #
$hash{'src_0.0'}=&versiontrack($furi);
$hash{'title_0.0'}=&Apache::lonnet::metadata($uri,'title');
$hash{'ids_'.$furi}='0.0';
@@ -906,7 +1287,9 @@ sub build_tmp_hashes {
sub unlink_tmpfiles {
my ($fn) = @_;
- if ($fn =~ m{^\Q$Apache::lonnet::perlvar{'lonDaemons'}\E/tmp/}) {
+ my $file_dir = dirname($fn);
+
+ if ($fn eq LONCAPA::tempdir()) {
my @files = qw (.db _symb.db .state _parms.db);
foreach my $file (@files) {
if (-e $fn.$file) {
@@ -960,6 +1343,9 @@ sub evalstate {
return $state;
}
+# This block seems to have code to manage/detect doubly defined
+# aliases in maps.
+
{
my %mapalias_cache;
sub count_mapalias {