Changeset 21411

Timestamp:

2010-01-04T23:10:50+13:00 (14 years ago)

Author:

davidb

Message:

Separation of different database back-ends into individual files

Location:

main/trunk/greenstone2/perllib

Files:

• dbutil (added)
• dbutil.pm (modified) (9 diffs)
• dbutil/gdbm.pm (added)
• dbutil/gdbmtxtgz.pm (added)
• dbutil/jdbm.pm (added)
• dbutil/mssql.pm (added)
• dbutil/sqlite.pm (added)

main/trunk/greenstone2/perllib/dbutil.pm

@@ -1 +1 @@
 ###########################################################################
 #
-# dbutil.pm -- utility functions for writing to different databases
+# dbutil.pm -- gateway to utilities for reading/writing to different databases
 # Copyright (C) 2008  DL Consulting Ltd
 #
@@ -26 +26 @@
 package dbutil;
 
-use Encode;
 use strict;
 
+
+use dbutil::gdbmtxtgz;
+use dbutil::gdbm;
+use dbutil::jdbm;
+use dbutil::sqlite;
+use dbutil::mssql;
 
 sub open_infodb_write_handle
@@ -37 +42 @@
   if ($infodb_type eq "sqlite") 
   {
-    return &open_infodb_write_handle_sqlite($infodb_file_path);
+    return &dbutil::sqlite::open_infodb_write_handle($infodb_file_path);
   } 
   elsif ($infodb_type eq "gdbm-txtgz") 
   {
-    return &open_infodb_write_handle_gdbm_txtgz($infodb_file_path);
+    return &dbutil::gdbmtxtgz::open_infodb_write_handle($infodb_file_path);
+  } 
+  elsif ($infodb_type eq "jdbm") 
+  {
+    return &dbutil::jdbm::open_infodb_write_handle($infodb_file_path);
   } 
   elsif ($infodb_type eq "mssql") 
   {
-    return &open_infodb_write_handle_mssql($infodb_file_path);
-  } 
-
-  # Use GDBM if the infodb type is empty or not one of the values above
-  return &open_infodb_write_handle_gdbm($infodb_file_path);
+    return &dbutil::mssql::open_infodb_write_handle($infodb_file_path);
+  } 
+
+  # Use GDBM if the infodb type is empty or not one of the values above
+  return &dbutil::gdbm::open_infodb_write_handle($infodb_file_path);
 }
 
@@ -60 +69 @@
   if ($infodb_type eq "sqlite")
   {
-    return &close_infodb_write_handle_sqlite($infodb_handle);
-  }
-  elsif ($infodb_type eq "gdbm-txtgz")
-  {
-    return &close_infodb_write_handle_gdbm_txtgz($infodb_handle);
-  }
-  elsif ($infodb_type eq "mssql")
-  {
-    return &close_infodb_write_handle_mssql($infodb_handle);
+    return &dbutil::sqlite::close_infodb_write_handle($infodb_handle);
+  }
+  elsif ($infodb_type eq "gdbm-txtgz")
+  {
+    return &dbutil::gdbmtxtgz::close_infodb_write_handle($infodb_handle);
+  }
+  elsif ($infodb_type eq "jdbm")
+  {
+    return &dbutil::jdbm::close_infodb_write_handle($infodb_handle);
+  }
+  elsif ($infodb_type eq "mssql")
+  {
+    return &dbutil::mssql::close_infodb_write_handle($infodb_handle);
   }
     
   # Use GDBM if the infodb type is empty or not one of the values above
-  return &close_infodb_write_handle_gdbm($infodb_handle);
+  return &dbutil::gdbm::close_infodb_write_handle($infodb_handle);
 }
 
@@ -92 +105 @@
   if ($infodb_type eq "sqlite")
   {
-    return &get_infodb_file_path_sqlite($collection_name, $infodb_directory_path);
-  }
-  elsif ($infodb_type eq "gdbm-txtgz")
-  {
-    return &get_infodb_file_path_gdbm_txtgz($collection_name, $infodb_directory_path);
+    return &dbutil::sqlite::get_infodb_file_path($collection_name, $infodb_directory_path);
+  }
+  elsif ($infodb_type eq "gdbm-txtgz")
+  {
+    return &dbutil::gdbmtxtgz::get_infodb_file_path($collection_name, $infodb_directory_path);
+  }
+  elsif ($infodb_type eq "jdbm")
+  {
+    return &dbutil::jdbm::get_infodb_file_path($collection_name, $infodb_directory_path);
   }
   elsif ($infodb_type eq "mssql")
@@ -108 +125 @@
     # Added by Jeffrey (2008/08/15 Friday)
     # No file path required for MS SQL, it is a server-client connection.
-    # At the moment the information is hard coded in open_infodb_write_handle_mssql
+    # At the moment the information is hard coded in dbutil::mssql::open_infodb_write_handle
     # the this might need some tidy up sometime.
     #==================================================================================================#
-    return &get_infodb_file_path_mssql($collection_name, $infodb_directory_path); 
+    return &dbutil::mssql::get_infodb_file_path($collection_name, $infodb_directory_path); 
   }
   
   # Use GDBM if the infodb type is empty or not one of the values above
-  return &get_infodb_file_path_gdbm($collection_name, $infodb_directory_path);
+  return &dbutil::gdbm::get_infodb_file_path($collection_name, $infodb_directory_path);
 }
 
@@ -127 +144 @@
   if ($infodb_type eq "sqlite")
   {
-    return &read_infodb_file_sqlite($infodb_file_path, $infodb_map);
-  }
-  elsif ($infodb_type eq "gdbm-txtgz")
-  {
-    return &read_infodb_file_gdbm_txtgz($infodb_file_path, $infodb_map);
-  }
-  elsif ($infodb_type eq "mssql")
-  {
-    return &read_infodb_file_mssql($infodb_file_path, $infodb_map);
+    return &dbutil::sqlite::read_infodb_file($infodb_file_path, $infodb_map);
+  }
+  elsif ($infodb_type eq "gdbm-txtgz")
+  {
+    return &dbutil::gdbmtxtgz::read_infodb_file($infodb_file_path, $infodb_map);
+  }
+  elsif ($infodb_type eq "jdbm")
+  {
+    return &dbutil::jdbm::read_infodb_file($infodb_file_path, $infodb_map);
+  }
+  elsif ($infodb_type eq "mssql")
+  {
+    return &dbutil::mssql::read_infodb_file($infodb_file_path, $infodb_map);
   }
   
   # Use GDBM if the infodb type is empty or not one of the values above
-  return &read_infodb_file_gdbm($infodb_file_path, $infodb_map);
+  return &dbutil::gdbm::read_infodb_file($infodb_file_path, $infodb_map);
 }
 
@@ -152 +173 @@
   if ($infodb_type eq "sqlite")
   {
-    return &write_infodb_entry_sqlite($infodb_handle, $infodb_key, $infodb_map);
-  }
-  elsif ($infodb_type eq "gdbm-txtgz")
-  {
-    return &write_infodb_entry_gdbm_txtgz($infodb_handle, $infodb_key, $infodb_map);
-  }
-  elsif ($infodb_type eq "mssql")
-  {
-    return &write_infodb_entry_mssql($infodb_handle, $infodb_key, $infodb_map);
-  }
-
-  # Use GDBM if the infodb type is empty or not one of the values above
-  return &write_infodb_entry_gdbm($infodb_handle, $infodb_key, $infodb_map);
+    return &dbutil::sqlite::write_infodb_entry($infodb_handle, $infodb_key, $infodb_map);
+  }
+  elsif ($infodb_type eq "gdbm-txtgz")
+  {
+    return &dbutil::gdbmtxtgz::write_infodb_entry($infodb_handle, $infodb_key, $infodb_map);
+  }
+  elsif ($infodb_type eq "jdbm")
+  {
+    return &dbutil::jdbm::write_infodb_entry($infodb_handle, $infodb_key, $infodb_map);
+  }
+  elsif ($infodb_type eq "mssql")
+  {
+    return &dbutil::mssql::write_infodb_entry($infodb_handle, $infodb_key, $infodb_map);
+  }
+
+  # Use GDBM if the infodb type is empty or not one of the values above
+  return &dbutil::gdbm::write_infodb_entry($infodb_handle, $infodb_key, $infodb_map);
 }
 
@@ -176 +201 @@
   if ($infodb_type eq "sqlite")
   {
-    return &delete_infodb_entry_sqlite($infodb_handle, $infodb_key);
-  }
-  elsif ($infodb_type eq "gdbm-txtgz")
-  {
-    return &delete_infodb_entry_gdbm_txtgz($infodb_handle, $infodb_key);
-  }
-  elsif ($infodb_type eq "mssql")
-  {
-    return &delete_infodb_entry_mssql($infodb_handle, $infodb_key);
-  }
-
-  # Use GDBM if the infodb type is empty or not one of the values above
-  return &delete_infodb_entry_gdbm($infodb_handle, $infodb_key);
-}
-
-
-
-# -----------------------------------------------------------------------------
-#   GDBM TXT-GZ IMPLEMENTATION
-# -----------------------------------------------------------------------------
-
-sub open_infodb_write_handle_gdbm_txtgz
-{
-  # Keep infodb in GDBM neutral form => save data as compressed text file, 
-  # read for txt2db to be run on it later (i.e. by the runtime system,
-  # first time the collection is ever accessed).  This makes it easier
-  # distribute pre-built collections to various architectures.
-  #
-  # NB: even if two architectures are little endian (e.g. Intel and 
-  # ARM procesors) GDBM does *not* guarantee that the database generated on 
-  # one will work on the other
-
-  my $infodb_file_path = shift(@_);
-
-  # Greenstone ships with gzip for windows, on $PATH
-
-  my $infodb_file_handle = undef;
-  if (!open($infodb_file_handle, "| gzip - > \"$infodb_file_path\""))
-  {
-    return undef;
-  }
-
-  return $infodb_file_handle;
-}
-
-
-sub close_infodb_write_handle_gdbm_txtgz
-{
-  my $infodb_handle = shift(@_);
-
-  close($infodb_handle);
-}
-
-
-sub get_infodb_file_path_gdbm_txtgz
-{
-  my $collection_name = shift(@_);
-  my $infodb_directory_path = shift(@_);
-
-  my $infodb_file_name = &util::get_dirsep_tail($collection_name).".txt.gz";
-  return &util::filename_cat($infodb_directory_path, $infodb_file_name);
-}
-
-
-sub read_infodb_file_gdbm_txtgz
-{
-  my $infodb_file_path = shift(@_);
-  my $infodb_map = shift(@_);
-
-  my $cmd = "gzip --decompress \"$infodb_file_path\"";
-
-  open (PIPEIN, "$cmd |") 
-  || die "Error: Couldn't open pipe from gzip: $!\n  $cmd\n";
-
-  my $infodb_line = "";
-  my $infodb_key = "";
-  my $infodb_value = "";
-  while (defined ($infodb_line = <PIPEIN>))
-  {
-    if ($infodb_line =~ /^\[([^\]]+)\]$/)
-    {
-      $infodb_key = $1;
-    }
-    elsif ($infodb_line =~ /^-{70}$/)
-    {
-      $infodb_map->{$infodb_key} = $infodb_value;
-      $infodb_key = "";
-      $infodb_value = "";
-    }
-    else
-    {
-      $infodb_value .= $infodb_line;
-    }
-  }
-
-  close (PIPEIN);
-}
-
-    
-sub write_infodb_entry_gdbm_txtgz
-{
-
-  my $infodb_handle = shift(@_);
-  my $infodb_key = shift(@_);
-  my $infodb_map = shift(@_);
-  
-  print $infodb_handle "[$infodb_key]\n";
-  foreach my $infodb_value_key (keys(%$infodb_map))
-  {
-    foreach my $infodb_value (@{$infodb_map->{$infodb_value_key}})
-    {
-      if ($infodb_value =~ /-{70,}/)
-      {
-        # if value contains 70 or more hyphens in a row we need to escape them
-        # to prevent txt2db from treating them as a separator
-        $infodb_value =~ s/-/&\#045;/gi;
-      }
-      print $infodb_handle "<$infodb_value_key>" . $infodb_value . "\n";
-    }
-  }
-  print $infodb_handle '-' x 70, "\n";
-}
-
-
-sub delete_infodb_entry_gdbm_txtgz
-{
-
-  my $infodb_handle = shift(@_);
-  my $infodb_key = shift(@_);
-  
-
-  # A minus at the end of a key (after the ]) signifies 'delete'
-  print $infodb_handle "[$infodb_key]-\n"; 
-
-  # The 70 minus signs are also needed, to help make the parsing by db2txt simple
-  print $infodb_handle '-' x 70, "\n";
-}
-
-
-
-# -----------------------------------------------------------------------------
-#   GDBM IMPLEMENTATION
-# -----------------------------------------------------------------------------
-
-sub open_infodb_write_handle_gdbm
-{
-  my $infodb_file_path = shift(@_);
-  my $opt_append = shift(@_);
-
-  my $txt2db_exe = &util::filename_cat($ENV{'GSDLHOME'},"bin",$ENV{'GSDLOS'}, "txt2db" . &util::get_os_exe());
-  my $infodb_file_handle = undef;
-  my $cmd = "\"$txt2db_exe\"";
-  if ((defined $opt_append) && ($opt_append eq "append")) {
-      $cmd .= " -append";
-  }
-  $cmd .= " \"$infodb_file_path\"";
-
-  if (!-e "$txt2db_exe" || !open($infodb_file_handle, "| $cmd"))
-  {
-    return undef;
-  }
-
-  return $infodb_file_handle;
-}
-
-
-
-sub close_infodb_write_handle_gdbm
-{
-  my $infodb_handle = shift(@_);
-
-  close($infodb_handle);
-}
-
-
-sub get_infodb_file_path_gdbm
-{
-  my $collection_name = shift(@_);
-  my $infodb_directory_path = shift(@_);
-
-  my $infodb_file_extension = ".gdb";
-  my $infodb_file_name = &util::get_dirsep_tail($collection_name) . $infodb_file_extension;
-  return &util::filename_cat($infodb_directory_path, $infodb_file_name);
-}
-
-
-sub read_infodb_file_gdbm
-{
-  my $infodb_file_path = shift(@_);
-  my $infodb_map = shift(@_);
-
-  open (PIPEIN, "db2txt \"$infodb_file_path\" |") || die "couldn't open pipe from db2txt \$infodb_file_path\"\n";
-  my $infodb_line = "";
-  my $infodb_key = "";
-  my $infodb_value = "";
-  while (defined ($infodb_line = <PIPEIN>))
-  {
-    if ($infodb_line =~ /^\[([^\]]+)\]$/)
-    {
-      $infodb_key = $1;
-    }
-    elsif ($infodb_line =~ /^-{70}$/)
-    {
-      $infodb_map->{$infodb_key} = $infodb_value;
-      $infodb_key = "";
-      $infodb_value = "";
-    }
-    else
-    {
-      $infodb_value .= $infodb_line;
-    }
-  }
-
-  close (PIPEIN);
-}
-
-sub read_infodb_keys_gdbm
-{
-  my $infodb_file_path = shift(@_);
-  my $infodb_map = shift(@_);
-
-  open (PIPEIN, "gdbmkeys \"$infodb_file_path\" |") || die "couldn't open pipe from gdbmkeys \$infodb_file_path\"\n";
-  my $infodb_line = "";
-  my $infodb_key = "";
-  my $infodb_value = "";
-  while (defined ($infodb_line = <PIPEIN>))
-  {
-      chomp $infodb_line; # remove end of line 
-
-      $infodb_map->{$infodb_line} = 1;
-  }
-
-  close (PIPEIN);
-}
-
-    
-sub write_infodb_entry_gdbm
-{
-  # With infodb_handle already set up, works the same as _gdbm_txtgz version
-  write_infodb_entry_gdbm_txtgz(@_);
-}
-
-sub delete_infodb_entry_gdbm
-{
-  # With infodb_handle already set up, works the same as _gdbm_txtgz version
-  delete_infodb_entry_gdbm_txtgz(@_);
-}
-
-
-
-# -----------------------------------------------------------------------------
-#   SQLITE IMPLEMENTATION
-# -----------------------------------------------------------------------------
-
-sub open_infodb_write_handle_sqlite
-{
-  my $infodb_file_path = shift(@_);
-
-  my $sqlite3_exe = &util::filename_cat($ENV{'GSDLHOME'},"bin",$ENV{'GSDLOS'}, "sqlite3" . &util::get_os_exe());
-  my $infodb_handle = undef;
-  if (!-e "$sqlite3_exe" || !open($infodb_handle, "| \"$sqlite3_exe\" \"$infodb_file_path\""))
-  {
-    return undef;
-  }
-
-  print $infodb_handle "CREATE TABLE IF NOT EXISTS data (key TEXT PRIMARY KEY, value TEXT);\n";
-  print $infodb_handle "CREATE TABLE IF NOT EXISTS document_metadata (id INTEGER PRIMARY KEY, docOID TEXT, element TEXT, value TEXT);\n";
-
-  # This is crucial for efficiency when importing large amounts of data
-  print $infodb_handle "CREATE INDEX IF NOT EXISTS dmd ON document_metadata(docOID);\n";
-
-  # This is very important for efficiency, otherwise each command will be actioned one at a time
-  print $infodb_handle "BEGIN TRANSACTION;\n";
-
-  return $infodb_handle;
-}
-
-
-sub close_infodb_write_handle_sqlite
-{
-  my $infodb_handle = shift(@_);
-
-  # Close the transaction we began after opening the file
-  print $infodb_handle "END TRANSACTION;\n";
-
-  # This is crucial for efficient queries on the database!
-  print $infodb_handle "CREATE INDEX IF NOT EXISTS dme ON document_metadata(element);\n";
-
-  close($infodb_handle);
-}
-
-
-sub get_infodb_file_path_sqlite
-{
-  my $collection_name = shift(@_);
-  my $infodb_directory_path = shift(@_);
-
-  my $infodb_file_extension = ".db";
-  my $infodb_file_name = &util::get_dirsep_tail($collection_name) . $infodb_file_extension;
-  return &util::filename_cat($infodb_directory_path, $infodb_file_name);
-}
-
-
-sub read_infodb_file_sqlite
-{
-  my $infodb_file_path = shift(@_);
-  my $infodb_map = shift(@_);
-
-  # !! TO IMPLEMENT
-}
-
-
-sub write_infodb_entry_sqlite
-{
-  my $infodb_handle = shift(@_);
-  my $infodb_key = shift(@_);
-  my $infodb_map = shift(@_);
-
-  # Add the key -> value mapping into the "data" table
-  my $infodb_entry_value = "";
-  foreach my $infodb_value_key (keys(%$infodb_map))
-  {
-    foreach my $infodb_value (@{$infodb_map->{$infodb_value_key}})
-    {
-      $infodb_entry_value .= "<$infodb_value_key>" . $infodb_value . "\n";
-    }
-  }
-
-  my $safe_infodb_key = &sqlite_safe($infodb_key);
-  print $infodb_handle "INSERT OR REPLACE INTO data (key, value) VALUES ('" . $safe_infodb_key . "', '" . &sqlite_safe($infodb_entry_value) . "');\n";
-
-  # If this infodb entry is for a document, add all the interesting document metadata to the
-  #   "document_metadata" table (for use by the dynamic classifiers)
-  if ($infodb_key !~ /\./ && $infodb_entry_value =~ /\<doctype\>doc\n/)
-  {
-    print $infodb_handle "DELETE FROM document_metadata WHERE docOID='" . $safe_infodb_key . "';\n";
-
-    foreach my $infodb_value_key (keys(%$infodb_map))
-    {
-      # We're not interested in most of the automatically added document metadata
-      next if ($infodb_value_key eq "archivedir" ||
-               $infodb_value_key eq "assocfilepath" ||
-               $infodb_value_key eq "childtype" ||
-               $infodb_value_key eq "contains" ||
-               $infodb_value_key eq "docnum" ||
-               $infodb_value_key eq "doctype" ||
-               $infodb_value_key eq "Encoding" ||
-               $infodb_value_key eq "FileSize" ||
-               $infodb_value_key eq "hascover" ||
-               $infodb_value_key eq "hastxt" ||
-               $infodb_value_key eq "lastmodified" ||
-               $infodb_value_key eq "metadataset" ||
-               $infodb_value_key eq "thistype" ||
-               $infodb_value_key =~ /^metadatafreq\-/ ||
-               $infodb_value_key =~ /^metadatalist\-/);
-
-      foreach my $infodb_value (@{$infodb_map->{$infodb_value_key}})
-      {
-        print $infodb_handle "INSERT INTO document_metadata (docOID, element, value) VALUES ('" . $safe_infodb_key . "', '" . &sqlite_safe($infodb_value_key) . "', '" . &sqlite_safe($infodb_value) . "');\n";
-      }
-    }
-  }
-}
-
-
-
-sub delete_infodb_entry_sqlite
-{
-  my $infodb_handle = shift(@_);
-  my $infodb_key = shift(@_);
-
-  # Delete the key from the "data" table
-
-  my $safe_infodb_key = &sqlite_safe($infodb_key);
-
-  print $infodb_handle "DELETE FROM data WHERE key='" . $safe_infodb_key . "';\n";
-
-  # If this infodb entry is for a document, delete the
-  #   "document_metadata" table entry also (for use by the dynamic classifiers)
-  if ($infodb_key !~ /\./)
-  {
-      # Possible for there not to be a docOID matching this infodb_key
-      # (entries are only made when <doctype> == doc
-      # Attempt to delete it, and don't complain if one isn't found
-
-      print $infodb_handle "DELETE FROM document_metadata WHERE docOID='" . $safe_infodb_key . "';\n";
-
-  }
-}
-
-
-
-
-
-
-sub sqlite_safe
-{
-  my $value = shift(@_);
-
-  # Escape any single quotes in the value
-  $value =~ s/\'/\'\'/g;
-
-  return $value;
-}
-
-
-
-# ----------------------------------------------------------------------------------------
-#   MSSQL IMPLEMENTATION
-# ----------------------------------------------------------------------------------------
-
-my $mssql_collection_name = "";
-my $mssql_data_table_name = "";
-my $mssql_document_metadata_table_name = "";
-
-
-sub open_infodb_write_handle_mssql
-{
-  my $infodb_file_path = shift(@_);
-
-  # You might have to install the DBD::ADO module from CPAN
-  #================================================================#
-  # Uncomment this if you want to use MSSQL!!!
-  # By the way, MSSQL only works on a Windows machine...
-  #================================================================#
-  #use DBI;
-  #use DBD::ADO;
-  #Win32::OLE->Option(CP => Win32::OLE::CP_UTF8);
-
-  # The hard coded server connection thingy which should be placed
-  # in some configuration file.
-  # If you have problem connecting to your MS SQL server:
-  # 1. Check if your MSSQL server has been started.
-  # 2. Check if the TCP/IP connection has been enabled.
-  # 3. Use telnet to the server 
-  # (don't forget to specify the port, which can be found in the configuration manager)
-  # If none of the above helped, the you need to start googling then.
-  my $host = "localhost,1660"; # Need to look up your SQL server and see what port is it using.
-  my $user = "sa";
-  my $pwd = "[When installing the MSSQL, you will be asked to input a password for the sa user, use that password]";
-  my $database = "[Create a database in MSSQL and use it here]";
-  
-  # Create the unique name for the table
-  # We do not want to change the database for the current running index
-  # Therefore we use timestamp and collection short name to create an unqiue name
-  my $cur_time = time();
-  my $unique_key = $mssql_collection_name . "_" . $cur_time;
-  $mssql_data_table_name = "data_" . $unique_key;
-  $mssql_document_metadata_table_name = "document_metadata_" . $unique_key;
-  print STDERR "MSSQL: Creating unique table name. Unique ID:[" . $unique_key . "]\n";
-      
-  # Store these information into the infodbfile  
-  open(FH, ">" . $infodb_file_path);
-  print FH "mss-host\t" . $host . "\n";
-  print FH "username\t" . $user . "\n";
-  print FH "password\t" . $pwd . "\n";
-  print FH "database\t" . $database . "\n";
-  print FH "tableid\t" . $unique_key . "\n";
-  close(FH);
-  print STDERR "MSSQL: Saving db info into :[" . $infodb_file_path . "]\n";
-
-  # Make the connection
-  my $dsn = "Provider=SQLNCLI;Server=$host;Database=$database";
-  my $infodb_handle = DBI->connect("dbi:ADO:$dsn", $user, $pwd, { RaiseError => 1, AutoCommit => 1}) || return undef;
-  print STDERR "MSSQL: Connect to MS SQL database. DSN:[" . $dsn . "]\n";
-
-  # Make sure the data table has been created.
-  my $data_table_checker_array = dbgetarray($infodb_handle, "SELECT name FROM sysobjects WHERE name = '" . $mssql_data_table_name . "' AND OBJECTPROPERTY(id,'IsUserTable') = 1");
-  if (scalar(@{$data_table_checker_array}) == 0)
-  {
-    dbquery($infodb_handle, "CREATE TABLE " . $mssql_data_table_name . " (one_key NVARCHAR(50) UNIQUE, one_value NVARCHAR(MAX))");
-  }
-  print STDERR "MSSQL: Making sure the data table(" . $mssql_data_table_name . ") exists\n";
-    
-  # Make sure the document_metadata table has been created.
-  my $document_metadata_table_checker_array = dbgetarray($infodb_handle, "SELECT name FROM sysobjects WHERE name = '" . $mssql_document_metadata_table_name . "' AND OBJECTPROPERTY(id,'IsUserTable') = 1");
-  if (scalar(@{$document_metadata_table_checker_array}) == 0)
-  {
-    dbquery($infodb_handle, "CREATE TABLE " . $mssql_document_metadata_table_name . " (id INTEGER IDENTITY(1,1) PRIMARY KEY, docOID NVARCHAR(50), element NVARCHAR(MAX), value NVARCHAR(MAX))");
-    dbquery($infodb_handle, "CREATE INDEX dmd ON " . $mssql_document_metadata_table_name . "(docOID)");
-  } 
-  print STDERR "MSSQL: Making sure the document_metadata table(" . $mssql_data_table_name . ") exists.\n";
-  
-  return $infodb_handle;
-}
-
-
-sub close_infodb_write_handle_mssql
-{
-  my $infodb_handle = shift(@_);    
-  
-  $infodb_handle->disconnect();
-}
-
-
-sub get_infodb_file_path_mssql
-{
-  my $collection_name = shift(@_);
-  my $infodb_directory_path = shift(@_);
-
-  my $infodb_file_extension = ".mssqldbinfo";
-  my $infodb_file_name = &util::get_dirsep_tail($collection_name) . $infodb_file_extension;
-  
-  # This will be used in the open_infodb_write_handle_mssql function
-  $mssql_collection_name =  $collection_name;
-
-  return &util::filename_cat($infodb_directory_path, $infodb_file_name);
-}
-
-
-sub read_infodb_file_mssql
-{
-  my $infodb_file_path = shift(@_);
-  my $infodb_map = shift(@_);
-
-  # !! TO IMPLEMENT
-}
-
-
-sub write_infodb_entry_mssql
-{
-  my $infodb_handle = shift(@_);
-  my $infodb_key = shift(@_);
-  my $infodb_map = shift(@_);
-  
-  # Add the key -> value mapping into the "data" table
-  my $infodb_entry_value = "";
-  foreach my $infodb_value_key (keys(%$infodb_map))
-  {
-    foreach my $infodb_value (@{$infodb_map->{$infodb_value_key}})
-    {
-      $infodb_entry_value .= "<$infodb_value_key>" . &Encode::decode_utf8($infodb_value) . "\n";
-    }
-  }
-  
-  # Prepare the query
-  my $safe_infodb_key = &mssql_safe($infodb_key);
-  my $query = "INSERT INTO " . $mssql_data_table_name . " (one_key, one_value) VALUES (N'" . $safe_infodb_key . "', N'" . &mssql_safe($infodb_entry_value) . "')";
-  dbquery($infodb_handle, $query);
-  
-  # If this infodb entry is for a document, add all the interesting document metadata to the
-  # "document_metadata" table (for use by the dynamic classifiers)
-  if ($infodb_key !~ /\./ && $infodb_entry_value =~ /\<doctype\>doc\n/)
-  {
-    dbquery($infodb_handle, "DELETE FROM " . $mssql_document_metadata_table_name . " WHERE docOID=N'" . $safe_infodb_key . "'");
-    
-    foreach my $infodb_value_key (keys(%$infodb_map))
-    {            
-      # We're not interested in most of the automatically added document metadata
-      next if ($infodb_value_key eq "archivedir" ||
-               $infodb_value_key eq "assocfilepath" ||
-               $infodb_value_key eq "childtype" ||
-               $infodb_value_key eq "contains" ||
-               $infodb_value_key eq "docnum" ||
-               $infodb_value_key eq "doctype" ||
-               $infodb_value_key eq "Encoding" ||
-               $infodb_value_key eq "FileSize" ||
-               $infodb_value_key eq "hascover" ||
-               $infodb_value_key eq "hastxt" ||
-               $infodb_value_key eq "lastmodified" ||
-               $infodb_value_key eq "metadataset" ||
-               $infodb_value_key eq "thistype" ||
-               $infodb_value_key =~ /^metadatafreq\-/ ||
-               $infodb_value_key =~ /^metadatalist\-/);
-      foreach my $infodb_value (@{$infodb_map->{$infodb_value_key}})
-      {
-        $infodb_handle->{LongReadLen} = 65535; # Added for the encoding issue
-        my $query = "INSERT INTO " . $mssql_document_metadata_table_name . " (docOID, element, value) VALUES (N'" . $safe_infodb_key . "', N'" . &mssql_safe(&Encode::decode_utf8($infodb_value_key)) . "', N'" . &mssql_safe(&Encode::decode_utf8($infodb_value)) . "')";
-        dbquery($infodb_handle, $query);
-      }
-    }
-  }
-}
-
-sub delete_infodb_entry_mssql
-{
-  my $infodb_handle = shift(@_);
-  my $infodb_key = shift(@_);
-  
-  # Delete the key from the "data" table
-
-  
-  # Prepare the query
-  my $safe_infodb_key = &mssql_safe($infodb_key);
-  my $query = "DELETE FROM " . $mssql_data_table_name . " WHERE one_key=N'" . $safe_infodb_key . "'";
-  dbquery($infodb_handle, $query);
-  
-  # If this infodb entry is for a document, add all the interesting document metadata to the
-  # "document_metadata" table (for use by the dynamic classifiers)
-  if ($infodb_key !~ /\./)
-  {
-      # Possible for there not to be a docOID matching this infodb_key
-      # (entries are only made when <doctype> == doc
-      # Attempt to delete it, and don't complain if one isn't found
-
-      dbquery($infodb_handle, "DELETE FROM " . $mssql_document_metadata_table_name . " WHERE docOID=N'" . $safe_infodb_key . "'");
-      
-  }
-}
-
-
-
-sub mssql_safe
-{
-  my $value = shift(@_);
-  
-  # Escape any single quotes in the value
-  $value =~ s/\'/\'\'/g;
-  
-  return $value;
-}
-
-
-sub dbquery
-{
-  my $infodb_handle = shift(@_);
-  my $sql_query = shift(@_);
-
-  # Execute the SQL statement
-  my $statement_handle = $infodb_handle->prepare($sql_query);
-  $statement_handle->execute();
-  if ($statement_handle->err) 
-  {
-    print STDERR "Error:" . $statement_handle->errstr . "\n";
-    return undef;
-  }
-  
-  return $statement_handle;
-}
-
-
-sub dbgetarray
-{
-  my $infodb_handle = shift(@_);
-  my $sql_query = shift(@_);
-  
-  my $statement_handle = dbquery($infodb_handle, $sql_query);
-  my $return_array = [];
-  
-  # Iterate through the results and push them into an array
-  if (!defined($statement_handle)) 
-  {
-    return [];
-  }
-  
-  while ((my $temp_hash = $statement_handle->fetchrow_hashref()))
-  {
-    push(@$return_array, $temp_hash);
-  }
-
-  return $return_array; 
+    return &dbutil::sqlite::delete_infodb_entry($infodb_handle, $infodb_key);
+  }
+  elsif ($infodb_type eq "gdbm-txtgz")
+  {
+    return &dbutil::gdbmtxtgz::delete_infodb_entry($infodb_handle, $infodb_key);
+  }
+  elsif ($infodb_type eq "jdbm")
+  {
+    return &dbutil::jdbm::delete_infodb_entry($infodb_handle, $infodb_key);
+  }
+  elsif ($infodb_type eq "mssql")
+  {
+    return &dbutil::mssql::delete_infodb_entry($infodb_handle, $infodb_key);
+  }
+
+  # Use GDBM if the infodb type is empty or not one of the values above
+  return &dbutil::gdbm::delete_infodb_entry($infodb_handle, $infodb_key);
 }