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Diff for /loncom/interface/loncoursedata.pm between versions 1.56 and 1.57

version 1.56, 2003/03/05 14:39:08 version 1.57, 2003/03/17 22:52:04
Line 52  use strict; Line 52  use strict;
 use Apache::Constants qw(:common :http);  use Apache::Constants qw(:common :http);
 use Apache::lonnet();  use Apache::lonnet();
 use Apache::lonhtmlcommon;  use Apache::lonhtmlcommon;
   use Time::HiRes;
   use Apache::lonmysql;
 use HTML::TokeParser;  use HTML::TokeParser;
 use GDBM_File;  use GDBM_File;
   
Line 1524  sub CheckForResidualDownload { Line 1526  sub CheckForResidualDownload {
   
 Returns a reference to a hash as described by $values.  $values is  Returns a reference to a hash as described by $values.  $values is
 assumed to be the result of   assumed to be the result of 
     join(':',map {&Apache::lonnet::escape($_)} %orighash;      join(':',map {&Apache::lonnet::escape($_)} %orighash);
   
 This is a helper function for get_current_state.  This is a helper function for get_current_state.
   
Line 1545  sub make_into_hash { Line 1547  sub make_into_hash {
   
 =pod  =pod
   
 =item &get_current_state($sname,$sdom,$symb,$courseid);  =head1 LOCAL DATA CACHING SUBROUTINES
   
   The local caching is done using MySQL.  There is no fall-back implementation
   if MySQL is not running.
   
   The programmers interface is to call &get_current_state() or some other
   primary interface subroutine (described below).  The internals of this 
   storage system are documented here.
   
   There are six tables used to store student performance data (the results of
   a dumpcurrent).  Each of these tables is created in MySQL with a name of
   $courseid_*****, where ***** is 'symb', 'part', or whatever is appropriate 
   for the table.  The tables and their purposes are described below.
   
   Some notes before we get started.
   
   Each table must have a PRIMARY KEY, which is a column or set of columns which
   will serve to uniquely identify a row of data.  NULL is not allowed!
   
   INDEXes work best on integer data.
   
   JOIN is used to combine data from many tables into one output.
   
   lonmysql.pm is used for some of the interface, specifically the table creation
   calls.  The inserts are done in bulk by directly calling the database handler.
   The SELECT ... JOIN statement used to retrieve the data does not have an
   interface in lonmysql.pm and I shudder at the thought of writing one.
   
   =head3 Table Descriptions
   
   =over 4
   
   =item $symb_table
   
   The symb_table has two columns.  The first is a 'symb_id' and the second
   is the text name for the 'symb' (limited to 64k).  The 'symb_id' is generated
   automatically by MySQL so inserts should be done on this table with an
   empty first element.  This table has its PRIMARY KEY on the 'symb_id'.
   
   =item $part_table
   
   The part_table has two columns.  The first is a 'part_id' and the second
   is the text name for the 'part' (limited to 100 characters).  The 'part_id' is
   generated automatically by MySQL so inserts should be done on this table with
   an empty first element.  This table has its PRIMARY KEY on the 'part' (100
   characters) and a KEY on 'part_id'.
   
   =item $student_table
   
   The student_table has two columns.  The first is a 'student_id' and the second
   is the text description of the 'student' (typically username:domain) (less
   than 100 characters).  The 'student_id' is automatically generated by MySQL.
   The use of the name 'student_id' is loaded, I know, but this ID is used ONLY 
   internally to the MySQL database and is not the same as the students ID 
   (stored in the students environment).  This table has its PRIMARY KEY on the
   'student' (100 characters).
   
   =item $updatetime_table
   
   The updatetime_table has two columns.  The first is 'student' (100 characters,
   typically username:domain).  The second is 'updatetime', which is an unsigned
   integer, NOT a MySQL date.  This table has its PRIMARY KEY on 'student' (100
   characters).
   
   =item $performance_table
   
   The performance_table has 9 columns.  The first three are 'symb_id', 
   'student_id', and 'part_id'.  These comprise the PRIMARY KEY for this table
   and are directly related to the $symb_table, $student_table, and $part_table
   described above.  MySQL does better indexing on numeric items than text,
   so we use these three "index tables".  The remaining columns are
   'solved', 'tries', 'awarded', 'award', 'awarddetail', and 'timestamp'.
   These are either the MySQL type TINYTEXT or various integers ('tries' and 
   'timestamp').  This table has KEYs of 'student_id' and 'symb_id'.
   For use of this table, see the functions described below.
   
   =item $parameters_table
   
   The parameters_table holds the data that does not fit neatly into the
   performance_table.  The parameters table has four columns: 'symb_id',
   'student_id', 'parameter', and 'value'.  'symb_id', 'student_id', and
   'parameter' comprise the PRIMARY KEY for this table.  'parameter' is 
   limited to 255 characters.  'value' is limited to 64k characters.
   
   =back
   
   =head3 Important Subroutines
   
   Here is a brief overview of the subroutines which are likely to be of 
   interest:
   
   =over 4
   
   =item &get_current_state(): programmers interface.
   
   =item &init_dbs(): table creation
   
   =item &update_student_data(): data storage calls
   
   =item &get_student_data_from_performance_cache(): data retrieval
   
   =back
   
   =head3 Main Documentation
   
   =over 4
   
   =cut
   
   ################################################
   ################################################
   
   ################################################
   ################################################
   {
   
   my $current_course ='';
   my $symb_table;
   my $part_table;
   my $student_table;
   my $updatetime_table;
   my $performance_table;
   my $parameters_table;
   
   ################################################
   ################################################
   
   =pod
   
   =item &setup_table_names()
   
   input: course id
   
   output: none
   
   Sets the package variables for the MySQL table names:
   
   =over 4
   
   =item $symb_table
   
   =item $part_table
   
   =item $student_table
   
   =item $updatetime_table
   
   =item $performance_table
   
   =item $parameters_table
   
   =back
   
   =cut
   
   ################################################
   ################################################
   sub setup_table_names {
       my $courseid = shift;
       if (! defined($courseid)) {
           $courseid = $ENV{'request.course.id'};
       }
       #
       # Set up database names
       my $base_id = $courseid;
       $symb_table        = $base_id.'_'.'symb';
       $part_table        = $base_id.'_'.'part';
       $student_table     = $base_id.'_'.'student';
       $updatetime_table  = $base_id.'_'.'updatetime';
       $performance_table = $base_id.'_'.'performance';
       $parameters_table  = $base_id.'_'.'parameters';
       return;
   }
   
   ################################################
   ################################################
   
   =pod
   
   =item &init_dbs()
   
   Input: course id
   
   Output: 0 on success, positive integer on error
   
   This routine issues the calls to lonmysql to create the tables used to
   store student data.
   
   =cut
   
   ################################################
   ################################################
   sub init_dbs {
       my $courseid = shift;
       &setup_table_names($courseid);
       #
       # Note - changes to this table must be reflected in the code that 
       # stores the data (calls &Apache::lonmysql::store_row with this table
       # id
       my $symb_table_def = {
           id => $symb_table,
           permanent => 'no',
           columns => [{ name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL',
                         auto_inc     => 'yes', },
                       { name => 'symb',
                         type => 'MEDIUMTEXT',
                         restrictions => 'NOT NULL'},
                       ],
           'PRIMARY KEY' => ['symb_id'],
       };
       #
       my $part_table_def = {
           id => $part_table,
           permanent => 'no',
           columns => [{ name => 'part_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL',
                         auto_inc     => 'yes', },
                       { name => 'part',
                         type => 'VARCHAR(100)',
                         restrictions => 'NOT NULL'},
                       ],
           'PRIMARY KEY' => ['part (100)'],
           'KEY' => [{ columns => ['part_id']},],
       };
       #
       my $student_table_def = {
           id => $student_table,
           permanent => 'no',
           columns => [{ name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL',
                         auto_inc     => 'yes', },
                       { name => 'student',
                         type => 'VARCHAR(100)',
                         restrictions => 'NOT NULL'},
                       ],
           'PRIMARY KEY' => ['student (100)'],
           'KEY' => [{ columns => ['student_id']},],
       };
       #
       my $updatetime_table_def = {
           id => $updatetime_table,
           permanent => 'no',
           columns => [{ name => 'student',
                         type => 'VARCHAR(100)',
                         restrictions => 'NOT NULL UNIQUE',},
                       { name => 'updatetime',
                         type => 'INT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       ],
           'PRIMARY KEY' => ['student (100)'],
       };
       #
       my $performance_table_def = {
           id => $performance_table,
           permanent => 'no',
           columns => [{ name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'part_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'solved',
                         type => 'TINYTEXT' },
                       { name => 'tries',
                         type => 'SMALLINT UNSIGNED' },
                       { name => 'awarded',
                         type => 'TINYTEXT' },
                       { name => 'award',
                         type => 'TINYTEXT' },
                       { name => 'awarddetail',
                         type => 'TINYTEXT' },
                       { name => 'timestamp',
                         type => 'INT UNSIGNED'},
                       ],
           'PRIMARY KEY' => ['symb_id','student_id','part_id'],
           'KEY' => [{ columns=>['student_id'] },
                     { columns=>['symb_id'] },],
       };
       #
       my $parameters_table_def = {
           id => $parameters_table,
           permanent => 'no',
           columns => [{ name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'parameter',
                         type => 'TINYTEXT',
                         restrictions => 'NOT NULL'  },
                       { name => 'value',
                         type => 'MEDIUMTEXT' },
                       ],
           'PRIMARY KEY' => ['symb_id','student_id','parameter (255)'],
       };
       #
       # Create the tables
       my $tableid;
       $tableid = &Apache::lonmysql::create_table($symb_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating symb_table: ".
                                    &Apache::lonmysql::get_error());
           return 1;
       }
       #
       $tableid = &Apache::lonmysql::create_table($part_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating part_table: ".
                                    &Apache::lonmysql::get_error());
           return 2;
       }
       #
       $tableid = &Apache::lonmysql::create_table($student_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating student_table: ".
                                    &Apache::lonmysql::get_error());
           return 3;
       }
       #
       $tableid = &Apache::lonmysql::create_table($updatetime_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating updatetime_table: ".
                                    &Apache::lonmysql::get_error());
           return 4;
       }
       #
       $tableid = &Apache::lonmysql::create_table($performance_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating preformance_table: ".
                                    &Apache::lonmysql::get_error());
           return 5;
       }
       #
       $tableid = &Apache::lonmysql::create_table($parameters_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating parameters_table: ".
                                    &Apache::lonmysql::get_error());
           return 6;
       }
       return 0;
   }
   
   ################################################
   ################################################
   
   =pod
   
   =item &get_part_id()
   
   Get the MySQL id of a problem part string.
   
   Input: $part
   
   Output: undef on error, integer $part_id on success.
   
   =item &get_part()
   
   Get the string describing a part from the MySQL id of the problem part.
   
   Input: $part_id
   
   Output: undef on error, $part string on success.
   
   =cut
   
   ################################################
   ################################################
   
   my %ids_by_part;
   my %parts_by_id;
   
   sub get_part_id {
       my ($part) = @_;
       if (! exists($ids_by_part{$part})) {
           &Apache::lonmysql::store_row($part_table,[undef,$part]);
           undef(%ids_by_part);
           my @Result = &Apache::lonmysql::get_rows($part_table);
           foreach (@Result) {
               $ids_by_part{$_->[1]}=$_->[0];
           }
       }
       return $ids_by_part{$part} if (exists($ids_by_part{$part}));
       return undef; # error
   }
   
   sub get_part {
       my ($part_id) = @_;
       if (! exists($parts_by_id{$part_id})  || 
           ! defined($parts_by_id{$part_id}) ||
           $parts_by_id{$part_id} eq '') {
           my @Result = &Apache::lonmysql::get_rows($part_table);
           foreach (@Result) {
               $parts_by_id{$_->[0]}=$_->[1];
           }
       }
       return $parts_by_id{$part_id} if(exists($parts_by_id{$part_id}));
       return undef; # error
   }
   
   ################################################
   ################################################
   
   =pod
   
   =item &get_symb_id()
   
   Get the MySQL id of a symb.
   
   Input: $symb
   
   Output: undef on error, integer $symb_id on success.
   
   =item &get_symb()
   
   Get the symb associated with a MySQL symb_id.
   
   Input: $symb_id
   
   Output: undef on error, $symb on success.
   
   =cut
   
   ################################################
   ################################################
   
   my %ids_by_symb;
   my %symbs_by_id;
   
   sub get_symb_id {
       my ($symb) = @_;
       if (! exists($ids_by_symb{$symb})) {
           &Apache::lonmysql::store_row($symb_table,[undef,$symb]);
           undef(%ids_by_symb);
           my @Result = &Apache::lonmysql::get_rows($symb_table);
           foreach (@Result) {
               $ids_by_symb{$_->[1]}=$_->[0];
           }
       }
       return $ids_by_symb{$symb} if(exists( $ids_by_symb{$symb}));
       return undef; # error
   }
   
   sub get_symb {
       my ($symb_id) = @_;
       if (! exists($symbs_by_id{$symb_id})  || 
           ! defined($symbs_by_id{$symb_id}) ||
           $symbs_by_id{$symb_id} eq '') {
           my @Result = &Apache::lonmysql::get_rows($symb_table);
           foreach (@Result) {
               $symbs_by_id{$_->[0]}=$_->[1];
           }
       }
       return $symbs_by_id{$symb_id} if(exists( $symbs_by_id{$symb_id}));
       return undef; # error
   }
   
   ################################################
   ################################################
   
   =pod
   
   =item &get_student_id()
   
   Get the MySQL id of a student.
   
   Input: $sname, $dom
   
   Output: undef on error, integer $student_id on success.
   
   =item &get_student()
   
   Get student username:domain associated with the MySQL student_id.
   
   Input: $student_id
   
   Output: undef on error, string $student (username:domain) on success.
   
   =cut
   
   ################################################
   ################################################
   
   my %ids_by_student;
   my %students_by_id;
   
   sub get_student_id {
       my ($sname,$sdom) = @_;
       my $student = $sname.':'.$sdom;
       if (! exists($ids_by_student{$student})) {
           &Apache::lonmysql::store_row($student_table,[undef,$student]);
           undef(%ids_by_student);
           my @Result = &Apache::lonmysql::get_rows($student_table);
           foreach (@Result) {
               $ids_by_student{$_->[1]}=$_->[0];
           }
       }
       return $ids_by_student{$student} if(exists( $ids_by_student{$student}));
       return undef; # error
   }
   
   sub get_student {
       my ($student_id) = @_;
       if (! exists($students_by_id{$student_id})  || 
           ! defined($students_by_id{$student_id}) ||
           $students_by_id{$student_id} eq '') {
           my @Result = &Apache::lonmysql::get_rows($student_table);
           foreach (@Result) {
               $students_by_id{$_->[0]}=$_->[1];
           }
       }
       return $students_by_id{$student_id} if(exists($students_by_id{$student_id}));
       return undef; # error
   }
   
   ################################################
   ################################################
   
   =pod
   
   =item &update_student_data()
   
   Input: $sname, $sdom, $courseid
   
   Output: $returnstatus, \%student_data
   
   $returnstatus is a string describing any errors that occured.  'okay' is the
   default.
   \%student_data is the data returned by a call to lonnet::currentdump.
   
   This subroutine loads a students data using lonnet::currentdump and inserts
   it into the MySQL database.  The inserts are done on two tables, 
   $performance_table and $parameters_table.  $parameters_table holds the data 
   that is not included in $performance_table.  See the description of 
   $performance_table elsewhere in this file.  The INSERT calls are made
   directly by this subroutine, not through lonmysql because we do a 'bulk'
   insert which takes advantage of MySQLs non-SQL compliant INSERT command to 
   insert multiple rows at a time.  If anything has gone wrong during this
   process, $returnstatus is updated with a description of the error and
   \%student_data is returned.  
   
   Notice we do not insert the data and immediately query it.  This means it
   is possible for there to be data returned this first time that is not 
   available the second time.  CYA.
   
   =cut
   
   ################################################
   ################################################
   sub update_student_data {
       my ($sname,$sdom,$courseid) = @_;
       #
       my $student_id = &get_student_id($sname,$sdom);
       my $student = $sname.':'.$sdom;
       #
       my $returnstatus = 'okay';
       #
       # Set up database names
       &setup_table_names($courseid);
       #
       # Download students data
       my $time_of_retrieval = time;
       my @tmp = &Apache::lonnet::currentdump($courseid,$sdom,$sname);
       if ((scalar(@tmp) > 0) && ($tmp[0] =~ /^error:/)) {
           &Apache::lonnet::logthis('error getting data for '.
                                    $sname.':'.$sdom.' in course '.$courseid.
                                    ':'.$tmp[0]);
           $returnstatus = 'error getting data';
           return $returnstatus;
       }
       if (scalar(@tmp) < 1) {
           return ('no data',undef);
       }
       my %student_data = @tmp;
       #
       # Remove all of the students data from the table
       &Apache::lonmysql::remove_from_table($performance_table,'student_id',
                                            $student_id);
       #
       # Store away the data
       #
       my $starttime = Time::HiRes::time;
       my $elapsed = 0;
       my $rows_stored;
       my $store_parameters_command  = 'INSERT INTO '.$parameters_table.
           ' VALUES ';
       my $store_performance_command = 'INSERT INTO '.$performance_table.
           ' VALUES ';
       my $dbh = &Apache::lonmysql::get_dbh();
       return 'error' if (! defined($dbh));
       while (my ($current_symb,$param_hash) = each(%student_data)) {
           #
           # make sure the symb is set up properly
           my $symb_id = &get_symb_id($current_symb);
           #
           # Load data into the tables
           while (my ($parameter,$value) = each (%$param_hash)) {
               my $newstring;
               if ($parameter !~ /(timestamp|resource\.(.*)\.(solved|tries|awarded|award|awarddetail|previous))/) {
                   $newstring = "('".join("','",
                                          $symb_id,$student_id,
                                          $parameter,$value)."'),";
                   if ($newstring !~ /''/) {
                       $store_parameters_command .= $newstring;
                       $rows_stored++;
                   }
               }
               next if ($parameter !~ /^resource\.(.*)\.solved$/);
               #
               my $part = $1;
               my $part_id = &get_part_id($part);
               next if (!defined($part_id));
               my $solved  = $value;
               my $tries   = $param_hash->{'resource.'.$part.'.tries'};
               my $awarded = $param_hash->{'resource.'.$part.'.awarded'};
               my $award   = $param_hash->{'resource.'.$part.'.award'};
               my $awarddetail = $param_hash->{'resource.'.$part.'.awarddetail'};
               my $timestamp = $param_hash->{'timestamp'};
               $solved      = '' if (! defined($awarded));
               $tries       = '' if (! defined($tries));
               $awarded     = '' if (! defined($awarded));
               $award       = '' if (! defined($award));
               $awarddetail = '' if (! defined($awarddetail));
               $newstring = "('".join("','",$symb_id,$student_id,$part_id,
                                      $solved,$tries,$awarded,$award,
                                      $awarddetail,$timestamp)."'),";
               $store_performance_command .= $newstring;
               $rows_stored++;
           }
       }
       chop $store_parameters_command;
       chop $store_performance_command;
       my $start = Time::HiRes::time;
       $dbh->do($store_parameters_command);
       if ($dbh->err()) {
           &Apache::lonnet::logthis(' bigass insert error:'.$dbh->errstr());
           &Apache::lonnet::logthis('command = '.$store_performance_command);
           $returnstatus = 'error: unable to insert parameters into database';
           return $returnstatus,\%student_data;
       }
       $dbh->do($store_performance_command);
       if ($dbh->err()) {
           &Apache::lonnet::logthis(' bigass insert error:'.$dbh->errstr());
           &Apache::lonnet::logthis('command = '.$store_parameters_command);
           $returnstatus = 'error: unable to insert performance into database';
           return $returnstatus,\%student_data;
       }
       $elapsed += Time::HiRes::time - $start;
       #
       # Set the students update time
       &Apache::lonmysql::replace_row($updatetime_table,
                                      [$student,$time_of_retrieval]);
       &Apache::lonnet::logthis('store       took: '.(Time::HiRes::time - $starttime).' for '.$rows_stored);
       &Apache::lonnet::logthis('mysql store took: '.$elapsed.' for '.$rows_stored);
       return ($returnstatus,\%student_data);
   }
   
   ################################################
   ################################################
   
   =pod
   
   =item &ensure_current_data()
   
   Input: $sname, $sdom, $courseid
   
   Output: $status, $data
   
   This routine ensures the data for a given student is up to date.  It calls
   &init_dbs() if the tables do not exist.  The $updatetime_table is queried
   to determine the time of the last update.  If the students data is out of
   date, &update_student_data() is called.  The return values from the call
   to &update_student_data() are returned.
   
   =cut
   
   ################################################
   ################################################
   sub ensure_current_data {
       my ($sname,$sdom,$courseid) = @_;
       my $status = 'okay';   # return value
       #
       &setup_table_names($courseid);
       #
       # if the tables do not exist, make them
       my @CurrentTable = &Apache::lonmysql::tables_in_db();
       my ($found_symb,$found_student,$found_part,$found_update,
           $found_performance,$found_parameters);
       foreach (@CurrentTable) {
           $found_symb        = 1 if ($_ eq $symb_table);
           $found_student     = 1 if ($_ eq $student_table);
           $found_part        = 1 if ($_ eq $part_table);
           $found_update      = 1 if ($_ eq $updatetime_table);
           $found_performance = 1 if ($_ eq $performance_table);
           $found_parameters  = 1 if ($_ eq $parameters_table);
       }
       if (!$found_symb        || !$found_update || 
           !$found_student     || !$found_part   ||
           !$found_performance || !$found_parameters) {
           if (&init_dbs($courseid)) {
               return 'error';
           }
       }
       #
       # Get the update time for the user
       my $updatetime = 0;
       my $modifiedtime = 1;
       #
       my $student = $sname.':'.$sdom;
       my @Result = &Apache::lonmysql::get_rows($updatetime_table,
                                                "student ='$student'");
       my $data = undef;
       if (@Result) {
           $updatetime = $Result[0]->[1];
       }
       if ($modifiedtime > $updatetime) {
           ($status,$data) = &update_student_data($sname,$sdom,$courseid);
       }
       return ($status,$data);
   }
   
   ################################################
   ################################################
   
   =pod
   
   =item &get_student_data_from_performance_cache()
   
   Input: $sname, $sdom, $symb, $courseid
   
   Output: hash reference containing the data for the given student.
   If $symb is undef, all the students data is returned.
   
   This routine is the heart of the local caching system.  See the description
   of $performance_table, $symb_table, $student_table, and $part_table.  The
   main task is building the MySQL request.  The tables appear in the request
   in the order in which they should be parsed by MySQL.  When searching
   on a student the $student_table is used to locate the 'student_id'.  All
   rows in $performance_table which have a matching 'student_id' are returned,
   with data from $part_table and $symb_table which match the entries in
   $performance_table, 'part_id' and 'symb_id'.  When searching on a symb,
   the $symb_table is processed first, with matching rows grabbed from 
   $performance_table and filled in from $part_table and $student_table in
   that order.  
   
   Running 'EXPLAIN ' on the 'SELECT' statements generated can be quite 
   interesting, especially if you play with the order the tables are listed.  
   
   =cut
   
   ################################################
   ################################################
   sub get_student_data_from_performance_cache {
       my ($sname,$sdom,$symb,$courseid)=@_;
       my $student = $sname.':'.$sdom if (defined($sname) && defined($sdom));
       &setup_table_names();
       #
       # Return hash
       my $studentdata;
       #
       my $dbh = &Apache::lonmysql::get_dbh();
       my $request = "SELECT ".
           "d.symb,c.part,a.solved,a.tries,a.awarded,a.award,a.awarddetail,".
               "a.timestamp ";
       if (defined($student)) {
           $request .= "FROM $student_table AS b ".
               "LEFT JOIN $performance_table AS a ON b.student_id=a.student_id ".
               "LEFT JOIN $part_table AS c ON c.part_id = a.part_id ".
               "LEFT JOIN $symb_table AS d ON d.symb_id = a.symb_id ".
                   "WHERE student='$student'";
           if (defined($symb) && $symb ne '') {
               $request .= " AND d.symb='".$dbh->quote($symb)."'";
           }
       } elsif (defined($symb) && $symb ne '') {
           $request .= "FROM $symb_table as d ".
               "LEFT JOIN $performance_table AS a ON d.symb_id=a.symb_id ".
               "LEFT JOIN $part_table    AS c ON c.part_id = a.part_id ".
               "LEFT JOIN $student_table AS b ON b.student_id = a.student_id ".
                   "WHERE symb='".$dbh->quote($symb)."'";
       }
       my $starttime = Time::HiRes::time;
       my $rows_retrieved = 0;
       my $sth = $dbh->prepare($request);
       $sth->execute();
       if ($sth->err()) {
           &Apache::lonnet::logthis("Unable to execute MySQL request:");
           &Apache::lonnet::logthis("\n".$request."\n");
           &Apache::lonnet::logthis("error is:".$sth->errstr());
           return undef;
       }
       foreach my $row (@{$sth->fetchall_arrayref}) {
           $rows_retrieved++;
           my ($symb,$part,$solved,$tries,$awarded,$award,$awarddetail,$time) = 
               (@$row);
           my $base = 'resource.'.$part;
           $studentdata->{$symb}->{$base.'.solved'}  = $solved;
           $studentdata->{$symb}->{$base.'.tries'}   = $tries;
           $studentdata->{$symb}->{$base.'.awarded'} = $awarded;
           $studentdata->{$symb}->{$base.'.award'}   = $award;
           $studentdata->{$symb}->{$base.'.awarddetail'} = $awarddetail;
           $studentdata->{$symb}->{'timestamp'} = $time if (defined($time) && $time ne '');
       }
       &Apache::lonnet::logthis('retrieve took: '.(Time::HiRes::time - $starttime).' for '.$rows_retrieved);
       return $studentdata;
   }
   
   ################################################
   ################################################
   
   =pod
   
   =item &get_current_state()
   
   Input: $sname,$sdom,$symb,$courseid
   
   Output: Described below
   
 Retrieve the current status of a students performance.  $sname and  Retrieve the current status of a students performance.  $sname and
 $sdom are the only required parameters.  If $symb is undef the results  $sdom are the only required parameters.  If $symb is undef the results
Line 1567  If $symb is specified, a hash of Line 2391  If $symb is specified, a hash of
 )  )
 is returned.  is returned.
   
 If no data is found for $symb, or if the student has not performance data,  If no data is found for $symb, or if the student has no performance data,
 an empty list is returned.  an empty list is returned.
   
 =cut  =cut
Line 1576  an empty list is returned. Line 2400  an empty list is returned.
 ################################################  ################################################
 sub get_current_state {  sub get_current_state {
     my ($sname,$sdom,$symb,$courseid,$forcedownload)=@_;      my ($sname,$sdom,$symb,$courseid,$forcedownload)=@_;
       if ($current_course ne $courseid) {
           # Clear out variables
           undef(%ids_by_part);
           undef(%parts_by_id);
           undef(%ids_by_symb);
           undef(%symbs_by_id);
           undef(%ids_by_student);
           undef(%students_by_id);
           $current_course = $courseid;
       }
     return () if (! defined($sname) || ! defined($sdom));      return () if (! defined($sname) || ! defined($sdom));
     #      #
     $courseid = $ENV{'request.course.id'} if (! defined($courseid));      $courseid = $ENV{'request.course.id'} if (! defined($courseid));
     #      #
 #    my $cachefilename = $Apache::lonnet::tmpdir.$ENV{'user.name'}.'_'.      my ($status,$data) = &ensure_current_data($sname,$sdom,$courseid);
 #                                                $ENV{'user.domain'}.'_'.  
 #                                                $courseid.'_student_data.db';  
     my $cachefilename = $Apache::lonnet::tmpdir.$ENV{'user.name'}.'_'.  
                                                 $ENV{'user.domain'}.'_'.  
                                                 $courseid.'_'.  
                                                 $sname.'_'.$sdom.  
                                                     '_student_data.db';  
     my %cache;  
     #  
     my %student_data; # return values go here  
     #  
     my $updatetime = 0;  
     my $key = &Apache::lonnet::escape($sname).':'.  
               &Apache::lonnet::escape($sdom).':';  
     # Open the cache file  
     if (tie(%cache,'GDBM_File',$cachefilename,&GDBM_READER(),0640)) {  
         if (exists($cache{$key.'time'})) {  
             $updatetime = $cache{$key.'time'};  
         }  
         untie(%cache);  
     }  
     # timestamp/devalidation check should go here.  
     my $modifiedtime = 1;  
     # Take whatever steps are neccessary at this point to give $modifiedtime a  
     # new value  
     #      #
     if (($updatetime < $modifiedtime) ||       if (defined($data)) {
         (defined($forcedownload) && $forcedownload)) {          return %$data;
         # Get all the students current data      } elsif ($status eq 'no data') {
         my $time_of_retrieval = time;          return ();
         my @tmp = &Apache::lonnet::currentdump($courseid,$sdom,$sname);  
         if ((scalar(@tmp) > 0) && ($tmp[0] =~ /^error:/)) {  
             &Apache::lonnet::logthis('error getting data for '.  
                                      $sname.':'.$sdom.' in course '.$courseid.  
                                      ':'.$tmp[0]);  
             return ();  
         }  
         %student_data = @tmp;  
         #  
         # Store away the data  
         #  
         # The cache structure is colon deliminated.    
         # $uname:$udom:time  => timestamp  
         # $uname:$udom:$symb => $parm1:$val1:$parm2:$val2 ...  
         #  
         # BEWARE: The colons are NOT escaped so can search with escaped   
         #         keys instead of unescaping every key.  
         #  
         if (tie(%cache,'GDBM_File',$cachefilename,&GDBM_WRCREAT(),0640)) {  
             while (my ($current_symb,$param_hash) = each(%student_data)) {  
                 my @Parameters = %{$param_hash};  
                 my $value = join(':',map { &Apache::lonnet::escape($_); }   
                                  @Parameters);  
                 # Store away the values  
                 $cache{$key.&Apache::lonnet::escape($current_symb)}=$value;  
             }  
             $cache{$key.'time'}=$time_of_retrieval;  
             untie(%cache);  
         }  
     } else {      } else {
         if (tie(%cache,'GDBM_File',$cachefilename,&GDBM_READER(),0640)) {          if ($status ne 'okay' && $status ne '') {
             if (defined($symb)) {              &Apache::lonnet::logthis('status = '.$status);
                 my  $searchkey = $key.&Apache::lonnet::escape($symb);              return ();
                 if (exists($cache{$searchkey})) {  
                     $student_data{$symb} = &make_into_hash($cache{$searchkey});  
                 }  
             } else {  
                 my $searchkey = '^'.$key.'(.*)$';#'  
                 while (my ($testkey,$params)=each(%cache)) {  
                     if ($testkey =~ /$searchkey/) { # \Q \E?  May be necc.  
                         my $tmpsymb = $1;  
                         next if ($tmpsymb =~ 'time');  
                         $student_data{&Apache::lonnet::unescape($tmpsymb)} =   
                             &make_into_hash($params);  
                     }  
                 }  
             }  
             untie(%cache);  
         }          }
           my $returnhash = &get_student_data_from_performance_cache($sname,$sdom,
                                                         $symb,$courseid);
           return %$returnhash if (defined($returnhash));
     }      }
     if (! defined($symb)) {      return ();
         return %student_data;  
     } elsif (exists($student_data{$symb})) {  
         return %{$student_data{$symb}};  
     } else {  
         return ();  
     }  
 }  }
   
 ################################################  ################################################
Line 1675  sub get_current_state { Line 2437  sub get_current_state {
   
 =pod  =pod
   
   =back
   
   =item End of Local Data Caching Subroutines
   
   =cut
   
   ################################################
   ################################################
   
   
   }
   ################################################
   ################################################
   
   =pod
   
   =head3 Classlist Subroutines
   
 =item &get_classlist();  =item &get_classlist();
   
 Retrieve the classist of a given class or of the current class.  Student  Retrieve the classist of a given class or of the current class.  Student
Line 1713  sub get_classlist { Line 2493  sub get_classlist {
     $cid = $cid || $ENV{'request.course.id'};      $cid = $cid || $ENV{'request.course.id'};
     $cdom = $cdom || $ENV{'course.'.$cid.'.domain'};      $cdom = $cdom || $ENV{'course.'.$cid.'.domain'};
     $cnum = $cnum || $ENV{'course.'.$cid.'.num'};      $cnum = $cnum || $ENV{'course.'.$cid.'.num'};
    my $now = time;      my $now = time;
     #      #
     my %classlist=&Apache::lonnet::dump('classlist',$cdom,$cnum);      my %classlist=&Apache::lonnet::dump('classlist',$cdom,$cnum);
     while (my ($student,$info) = each(%classlist)) {      while (my ($student,$info) = each(%classlist)) {
Removed from v.1.56  
changed lines
  Added in v.1.57

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