--- loncom/metadata_database/parse_activity_log.pl	2004/12/16 19:29:20	1.7
+++ loncom/metadata_database/parse_activity_log.pl	2004/12/20 19:53:36	1.8
@@ -2,7 +2,7 @@
 #
 # The LearningOnline Network
 #
-# $Id: parse_activity_log.pl,v 1.7 2004/12/16 19:29:20 matthew Exp $
+# $Id: parse_activity_log.pl,v 1.8 2004/12/20 19:53:36 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -37,9 +37,22 @@
 #   5     Unspecified error?
 #
 
+#
+# Notes:
+#
+# Logging is done via the $logthis variable, which may be the result of 
+# overcleverness.  log via $logthis->('logtext');  Those are parentheses,
+# not curly braces.  If the -log command line parameter is set, the $logthis
+# routine is set to a routine which writes to a file.  If the command line
+# parameter is not set $logthis is set to &nothing, which does what you
+# would expect.
+#
+
 use strict;
 use DBI;
-use lib '/home/httpd/lib/perl/Apache';
+use lib '/home/httpd/lib/perl/';
+use LONCAPA::Configuration();
+use Apache::lonmysql();
 use lonmysql();
 use Time::HiRes();
 use Getopt::Long();
@@ -93,8 +106,8 @@ my $initial_time = Time::HiRes::time;
 ##
 ## Read in configuration parameters
 ##
-my %perlvar;
-&initialize_configuration();
+my %perlvar = %{&LONCAPA::Configuration::read_conf('loncapa.conf')};
+
 if (! defined($domain) || $domain eq '') {
     $domain = $perlvar{'lonDefDomain'};
 }
@@ -260,36 +273,33 @@ my $activity_table_def =
       'KEY' => [{columns => ['student_id']},
                 {columns => ['time']},],
 };
-my @Activity_Table = ($activity_table_def); 
-
-#my @ID_Tables = ($student_table_def,$res_table_def,
-#                 $action_table_def,$machine_table_def);
 
+my @Activity_Table = ($activity_table_def);
 my @ID_Tables = ($student_table_def,$res_table_def,$machine_table_def);
-                      
-
 ##
 ## End of table definitions
 ##
 
-# 
 $logthis->('Connectiong to mysql');
-&Apache::lonmysql::set_mysql_user_and_password($perlvar{'lonSqlUser'},
+&Apache::lonmysql::set_mysql_user_and_password('www',
                                                $perlvar{'lonSqlAccess'});
 if (!&Apache::lonmysql::verify_sql_connection()) {
     warn "Unable to connect to MySQL database.";
     $logthis->("Unable to connect to MySQL database.");
     exit 3;
 }
-
 $logthis->('SQL connection is up');
 
 if ($drop) { &drop_tables(); $logthis->('dropped tables'); }
 
 if (-s $gz_sql_filename) {
-    # if ANY one of the tables does not exist, load the tables from the
-    # backup.
+    my $backup_modification_time = (stat($gz_sql_filename))[9];
+    $logthis->($gz_sql_filename.' was last modified '.
+               localtime($backup_modification_time).
+               '('.$backup_modification_time.')');
+    # Check for missing tables
     my @Current_Tables = &Apache::lonmysql::tables_in_db();
+    $logthis->(join(',',@Current_Tables));
     my %Found;
     foreach my $tablename (@Current_Tables) {
         foreach my $table (@Activity_Table,@ID_Tables) {
@@ -298,14 +308,37 @@ if (-s $gz_sql_filename) {
             }
         }
     }
+    $logthis->('Found tables '.join(',',keys(%Found)));
+    my $missing_a_table = 0;
     foreach my $table (@Activity_Table,@ID_Tables) {    
+        # Hmmm, should I dump the tables?
         if (! $Found{$table->{'id'}}) {
-            $time_this->();
-            &load_backup_tables($gz_sql_filename);
-            $time_this->('load backup tables');
+            $logthis->('Missing table '.$table->{'id'});
+            $missing_a_table = 1;
             last;
         }
     }
+    if ($missing_a_table) {
+        my $table_modification_time = $backup_modification_time;
+        # If the backup happened prior to the last table modification,
+        foreach my $table (@Activity_Table,@ID_Tables) {    
+            my %tabledata = &Apache::lonmysql::table_information($table->{'id'});
+            next if (! scalar(keys(%tabledata))); # table does not exist
+            if ($table_modification_time < $tabledata{'Update_time'}) {
+                $table_modification_time = $tabledata{'Update_time'};
+            }
+        }
+        $logthis->("Table modification time = ".$table_modification_time);
+        if ($table_modification_time > $backup_modification_time) {
+            # Save the current tables in case we need them another time.
+            my $backup_name = $gz_sql_filename.'.'.time;
+            $logthis->('Backing existing tables up in '.$backup_name);
+            &backup_tables($backup_name);
+        }
+        $time_this->();
+        &load_backup_tables($gz_sql_filename);
+        $time_this->('load backup tables');
+    }
 }
 
 ##
@@ -609,8 +642,8 @@ sub backup_tables {
 sub load_backup_tables {
     my ($gz_sql_filename) = @_;
     if (-s $gz_sql_filename) {
-        &logthis('loading data from gzipped sql file');
-        my $command='gzip -dc activity.log.sql.gz | mysql --database=loncapa';
+        $logthis->('loading data from gzipped sql file');
+        my $command='gzip -dc '.$gz_sql_filename.' | mysql --database=loncapa';
         system($command);
         $logthis->('finished loading gzipped data');;
     } else {
@@ -621,14 +654,6 @@ sub load_backup_tables {
 ##
 ## 
 ##
-sub initialize_configuration {
-    # Fake it for now:
-    $perlvar{'lonSqlUser'} = 'www';
-    $perlvar{'lonSqlAccess'} = 'localhostkey';
-    $perlvar{'lonUsersDir'} = '/home/httpd/lonUsers';
-    $perlvar{'lonDefDomain'} = '103';
-}
-
 sub update_process_name {
     my ($text) = @_;
     $0 = 'parse_activity_log.pl: '.$text;