Diff of /Sprout/ERDB.pm

-revision 1.39, Sun Mar 26 17:24:55 2006 UTC
+revision 1.42, Wed Apr 19 03:34:15 2006 UTC
 Line 9
      use DBObject;
      use Stats;
      use Time::HiRes qw(gettimeofday);
+     use Digest::MD5 qw(md5_base64);
      use FIG;
  =head1 Entity-Relationship Database Package
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+Line 126
  variable-length string, maximum 255 characters
+ =item hash-string
+ variable-length string, maximum 22 characters
  =back
+ The hash-string data type has a special meaning. The actual key passed into the loader will
+ be a string, but it will be digested into a 22-character MD5 code to save space. Although the
+ MD5 algorithm is not perfect, it is extremely unlikely two strings will have the same
+ digest. Therefore, it is presumed the keys will be unique. When the database is actually
+ in use, the hashed keys will be presented rather than the original values. For this reason,
+ they should not be used for entities where the key is meaningful.
  =head3 Global Tags
  The entire database definition must be inside a B<Database> tag. The display name of
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+Line 322
                    date =>    { sqlType => 'BIGINT',             maxLen => 80,           avgLen =>   8, dataGen => "DateGen(-7, 7, IntGen(0,1400))" },
                    float =>   { sqlType => 'DOUBLE PRECISION',   maxLen => 40,           avgLen =>   8, dataGen => "FloatGen(0.0, 100.0)" },
                    boolean => { sqlType => 'SMALLINT',           maxLen => 1,            avgLen =>   1, dataGen => "IntGen(0, 1)" },
+                  'hash-string' =>
+                              { sqlType => 'VARCHAR(22)',        maxLen => 22,           avgLen =>  22, dataGen => "SringGen(22)" },
                   'key-string' =>
                               { sqlType => 'VARCHAR(40)',        maxLen => 40,           avgLen =>  10, dataGen => "StringGen(IntGen(10,40))" },
                   'name-string' =>
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+Line 701
      return $retVal;
  }
+ =head3 DigestFields
+ C<< $erdb->DigestFields($relName, $fieldList); >>
+ Digest the strings in the field list that correspond to data type C<hash-string> in the
+ specified relation.
+ =over 4
+ =item relName
+ Name of the relation to which the fields belong.
+ =item fieldList
+ List of field contents to be loaded into the relation.
+ =back
+ =cut
+ #: Return Type ;
+ sub DigestFields {
+     # Get the parameters.
+     my ($self, $relName, $fieldList) = @_;
+     # Get the relation definition.
+     my $relData = $self->_FindRelation($relName);
+     # Get the list of field descriptors.
+     my $fieldTypes = $relData->{Fields};
+     my $fieldCount = scalar @{$fieldTypes};
+     # Loop through the two lists.
+     for (my $i = 0; $i < $fieldCount; $i++) {
+         # Get the type of the current field.
+         my $fieldType = $fieldTypes->[$i]->{type};
+         # If it's a hash string, digest it in place.
+         if ($fieldType eq 'hash-string') {
+             $fieldList->[$i] = md5_base64($fieldList->[$i]);
+         }
+     }
+ }
  =head3 CreateIndex
  C<< $erdb->CreateIndex($relationName); >>
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+Line 1077
              my $nameLength = 2 + length $mappedName;
              # Get the real object name for this mapped name.
              my $objectName = $mappedNameHash{$mappedName};
+             Trace("Processing $mappedName for object $objectName.") if T(4);
              # Get the object's field list.
              my $fieldList = $self->GetFieldTable($objectName);
              # Find the field references for this object.
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+Line 1092
                  if (!exists $fieldList->{$fieldName}) {
                      Confess("Field $fieldName not found for object $objectName.");
                  } else {
+                     Trace("Processing $fieldName at position $pos.") if T(4);
                      # Get the field's relation.
                      my $relationName = $fieldList->{$fieldName}->{relation};
                      # Now we have a secondary relation. We need to insure it matches the
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+Line 1169
          }
          # Add the filter and the join clauses (if any) to the SELECT command.
          if ($filterString) {
+             Trace("Filter string is \"$filterString\".") if T(4);
              push @joinWhere, "($filterString)";
          }
          if (@joinWhere) {
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+Line 1180
              $command .= " $orderClause";
          }
      }
-     Trace("SQL query: $command") if T(SQL => 4);
+     Trace("SQL query: $command") if T(SQL => 3);
      Trace("PARMS: '" . (join "', '", @params) . "'") if (T(SQL => 4) && (@params > 0));
      my $sth = $dbh->prepare_command($command);
      # Execute it with the parameters bound in.
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+Line 2650
              # Determine if this relationship has our entity in one of its link fields.
              my $fromEntity = $relationship->{from};
              my $toEntity = $relationship->{to};
-             Trace("Join check for relationship $relationshipName from $fromEntity to $toEntity.") if T(4);
+             Trace("Join check for relationship $relationshipName from $fromEntity to $toEntity.") if T(Joins => 4);
              if ($fromEntity eq $entityName) {
                  if ($toEntity eq $entityName) {
                      # Here the relationship is recursive.
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+Line 2739
      return $metadata;
  }
+ =head3 SortNeeded
+ C<< my $flag = $erdb->SortNeeded($relationName); >>
+ Return TRUE if the specified relation should be sorted during loading to remove duplicate keys,
+ else FALSE.
+ =over 4
+ =item relationName
+ Name of the relation to be examined.
+ =item RETURN
+ Returns TRUE if the relation needs a sort, else FALSE.
+ =back
+ =cut
+ #: Return Type $;
+ sub SortNeeded {
+     # Get the parameters.
+     my ($self, $relationName) = @_;
+     # Declare the return variable.
+     my $retVal = 0;
+     # Find out if the relation is a primary entity relation.
+     my $entityTable = $self->{Entities};
+     if (exists $entityTable->{$relationName}) {
+         my $keyType = $entityTable->{$relationName}->{keyType};
+         # If the key is not a hash string, we must do the sort.
+         if ($keyType ne 'hash-string') {
+             $retVal = 1;
+         }
+     }
+     # Return the result.
+     return $retVal;
+ }
  =head3 CreateRelationshipIndex
  Create an index for a relationship's relation.

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+Added in v.1.42

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