# DB_File.pm -- Perl 5 interface to Berkeley DB
#
# written by Paul Marquess (pmarquess@bfsec.bt.co.uk)
-# last modified 12th Mar 1997
-# version 1.12
+# last modified 19th November 1998
+# version 1.61
#
-# Copyright (c) 1995, 1996, 1997 Paul Marquess. All rights reserved.
+# Copyright (c) 1995-8 Paul Marquess. All rights reserved.
# This program is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.
croak ref($self) . " does not define the method ${method}" ;
}
-sub DESTROY { undef %{$_[0]} }
sub FIRSTKEY { my $self = shift ; $self->NotHere("FIRSTKEY") }
sub NEXTKEY { my $self = shift ; $self->NotHere("NEXTKEY") }
sub CLEAR { my $self = shift ; $self->NotHere("CLEAR") }
package DB_File ;
use strict;
-use vars qw($VERSION @ISA @EXPORT $AUTOLOAD $DB_BTREE $DB_HASH $DB_RECNO) ;
+use vars qw($VERSION @ISA @EXPORT $AUTOLOAD $DB_BTREE $DB_HASH $DB_RECNO $db_version) ;
use Carp;
-$VERSION = "1.12" ;
+$VERSION = "1.61" ;
#typedef enum { DB_BTREE, DB_HASH, DB_RECNO } DBTYPE;
$DB_BTREE = new DB_File::BTREEINFO ;
}
-# import borrowed from IO::File
-# exports Fcntl constants if available.
-sub import {
- my $pkg = shift;
- my $callpkg = caller;
- Exporter::export $pkg, $callpkg, @_;
- eval {
- require Fcntl;
- Exporter::export 'Fcntl', $callpkg, '/^O_/';
- };
-}
+eval {
+ # Make all Fcntl O_XXX constants available for importing
+ require Fcntl;
+ my @O = grep /^O_/, @Fcntl::EXPORT;
+ Fcntl->import(@O); # first we import what we want to export
+ push(@EXPORT, @O);
+};
+
+## import borrowed from IO::File
+## exports Fcntl constants if available.
+#sub import {
+# my $pkg = shift;
+# my $callpkg = caller;
+# Exporter::export $pkg, $callpkg, @_;
+# eval {
+# require Fcntl;
+# Exporter::export 'Fcntl', $callpkg, '/^O_/';
+# };
+#}
bootstrap DB_File $VERSION;
# Preloaded methods go here. Autoload methods go after __END__, and are
# processed by the autosplit program.
-sub TIEHASH
+sub tie_hash_or_array
{
my (@arg) = @_ ;
+ my $tieHASH = ( (caller(1))[3] =~ /TIEHASH/ ) ;
$arg[4] = tied %{ $arg[4] }
if @arg >= 5 && ref $arg[4] && $arg[4] =~ /=HASH/ && tied %{ $arg[4] } ;
- DoTie_(@arg) ;
+ # make recno in Berkeley DB version 2 work like recno in version 1.
+ if ($db_version > 1 and defined $arg[4] and $arg[4] =~ /RECNO/ and
+ $arg[1] and ! -e $arg[1]) {
+ open(FH, ">$arg[1]") or return undef ;
+ close FH ;
+ chmod $arg[3] ? $arg[3] : 0666 , $arg[1] ;
+ }
+
+ DoTie_($tieHASH, @arg) ;
+}
+
+sub TIEHASH
+{
+ tie_hash_or_array(@_) ;
+}
+
+sub TIEARRAY
+{
+ tie_hash_or_array(@_) ;
+}
+
+sub CLEAR
+{
+ my $self = shift;
+ my $key = "" ;
+ my $value = "" ;
+ my $status = $self->seq($key, $value, R_FIRST());
+ my @keys;
+
+ while ($status == 0) {
+ push @keys, $key;
+ $status = $self->seq($key, $value, R_NEXT());
+ }
+ foreach $key (reverse @keys) {
+ my $s = $self->del($key);
+ }
}
-*TIEARRAY = \&TIEHASH ;
+sub EXTEND { }
+sub STORESIZE
+{
+ my $self = shift;
+ my $length = shift ;
+ my $current_length = $self->length() ;
+
+ if ($length < $current_length) {
+ my $key ;
+ for ($key = $current_length - 1 ; $key >= $length ; -- $key)
+ { $self->del($key) }
+ }
+ elsif ($length > $current_length) {
+ $self->put($length-1, "") ;
+ }
+}
+
sub get_dup
{
croak "Usage: \$db->get_dup(key [,flag])\n"
1;
__END__
-=cut
-
=head1 NAME
-DB_File - Perl5 access to Berkeley DB
+DB_File - Perl5 access to Berkeley DB version 1.x
=head1 SYNOPSIS
=head1 DESCRIPTION
B<DB_File> is a module which allows Perl programs to make use of the
-facilities provided by Berkeley DB. If you intend to use this
-module you should really have a copy of the Berkeley DB manual pages at
-hand. The interface defined here mirrors the Berkeley DB interface
-closely.
-
-Please note that this module will only work with version 1.x of
-Berkeley DB. Once Berkeley DB version 2 is released, B<DB_File> will be
-upgraded to work with it.
+facilities provided by Berkeley DB version 1.x (if you have a newer
+version of DB, see L<Using DB_File with Berkeley DB version 2>). It is
+assumed that you have a copy of the Berkeley DB manual pages at hand
+when reading this documentation. The interface defined here mirrors the
+Berkeley DB interface closely.
Berkeley DB is a C library which provides a consistent interface to a
number of database formats. B<DB_File> provides an interface to all
=back
+=head2 Using DB_File with Berkeley DB version 2
+
+Although B<DB_File> is intended to be used with Berkeley DB version 1,
+it can also be used with version 2. In this case the interface is
+limited to the functionality provided by Berkeley DB 1.x. Anywhere the
+version 2 interface differs, B<DB_File> arranges for it to work like
+version 1. This feature allows B<DB_File> scripts that were built with
+version 1 to be migrated to version 2 without any changes.
+
+If you want to make use of the new features available in Berkeley DB
+2.x, use the Perl module B<BerkeleyDB> instead.
+
+At the time of writing this document the B<BerkeleyDB> module is still
+alpha quality (the version number is < 1.0), and so unsuitable for use
+in any serious development work. Once its version number is >= 1.0, it
+is considered stable enough for real work.
+
+B<Note:> The database file format has changed in Berkeley DB version 2.
+If you cannot recreate your databases, you must dump any existing
+databases with the C<db_dump185> utility that comes with Berkeley DB.
+Once you have upgraded DB_File to use Berkeley DB version 2, your
+databases can be recreated using C<db_load>. Refer to the Berkeley DB
+documentation for further details.
+
+Please read L<COPYRIGHT> before using version 2.x of Berkeley DB with
+DB_File.
+
=head2 Interface to Berkeley DB
B<DB_File> allows access to Berkeley DB files using the tie() mechanism
In list context, it returns all the values which match C<$key>. Note
that the values will be returned in an apparently random order.
-In list context, if the second parameter is present and evaluates TRUE,
-the method returns an associative array. The keys of the associative
-array correspond to the the values that matched in the BTREE and the
-values of the array are a count of the number of times that particular
-value occurred in the BTREE.
+In list context, if the second parameter is present and evaluates
+TRUE, the method returns an associative array. The keys of the
+associative array correspond to the values that matched in the BTREE
+and the values of the array are a count of the number of times that
+particular value occurred in the BTREE.
So assuming the database created above, we can use C<get_dup> like
this:
=head2 Extra Methods
-As you can see from the example above, the tied array interface is
-quite limited. To make the interface more useful, a number of methods
-are supplied with B<DB_File> to simulate the standard array operations
-that are not currently implemented in Perl's tied array interface. All
-these methods are accessed via the object returned from the tie call.
+If you are using a version of Perl earlier than 5.004_57, the tied
+array interface is quite limited. The example script above will work,
+but you won't be able to use C<push>, C<pop>, C<shift>, C<unshift>
+etc. with the tied array.
+
+To make the interface more useful for older versions of Perl, a number
+of methods are supplied with B<DB_File> to simulate the missing array
+operations. All these methods are accessed via the object returned from
+the tie call.
Here are the methods:
=head2 The untie() Gotcha
-If you make use of the Berkeley DB API, it is is I<very> strongly
+If you make use of the Berkeley DB API, it is I<very> strongly
recommended that you read L<perltie/The untie Gotcha>.
Even if you don't currently make use of the API interface, it is still
=head1 HISTORY
-=over
-
-=item 0.1
-
-First Release.
-
-=item 0.2
-
-When B<DB_File> is opening a database file it no longer terminates the
-process if I<dbopen> returned an error. This allows file protection
-errors to be caught at run time. Thanks to Judith Grass
-E<lt>grass@cybercash.comE<gt> for spotting the bug.
-
-=item 0.3
-
-Added prototype support for multiple btree compare callbacks.
-
-=item 1.0
-
-B<DB_File> has been in use for over a year. To reflect that, the
-version number has been incremented to 1.0.
-
-Added complete support for multiple concurrent callbacks.
-
-Using the I<push> method on an empty list didn't work properly. This
-has been fixed.
-
-=item 1.01
-
-Fixed a core dump problem with SunOS.
-
-The return value from TIEHASH wasn't set to NULL when dbopen returned
-an error.
-
-=item 1.02
-
-Merged OS/2 specific code into DB_File.xs
-
-Removed some redundant code in DB_File.xs.
-
-Documentation update.
-
-Allow negative subscripts with RECNO interface.
-
-Changed the default flags from O_RDWR to O_CREAT|O_RDWR.
-
-The example code which showed how to lock a database needed a call to
-C<sync> added. Without it the resultant database file was empty.
-
-Added get_dup method.
-
-=item 1.03
-
-Documentation update.
-
-B<DB_File> now imports the constants (O_RDWR, O_CREAT etc.) from Fcntl
-automatically.
-
-The standard hash function C<exists> is now supported.
-
-Modified the behavior of get_dup. When it returns an associative
-array, the value is the count of the number of matching BTREE values.
-
-=item 1.04
-
-Minor documentation changes.
-
-Fixed a bug in hash_cb. Patches supplied by Dave Hammen,
-E<lt>hammen@gothamcity.jsc.nasa.govE<gt>.
-
-Fixed a bug with the constructors for DB_File::HASHINFO,
-DB_File::BTREEINFO and DB_File::RECNOINFO. Also tidied up the
-constructors to make them C<-w> clean.
-
-Reworked part of the test harness to be more locale friendly.
-
-=item 1.05
-
-Made all scripts in the documentation C<strict> and C<-w> clean.
-
-Added logic to F<DB_File.xs> to allow the module to be built after Perl
-is installed.
-
-=item 1.06
-
-Minor namespace cleanup: Localized C<PrintBtree>.
-
-=item 1.07
-
-Fixed bug with RECNO, where bval wasn't defaulting to "\n".
-
-=item 1.08
-
-Documented operation of bval.
-
-=item 1.09
-
-Minor bug fix in DB_File::HASHINFO, DB_File::RECNOINFO and
-DB_File::BTREEINFO.
-
-Changed default mode to 0666.
-
-=item 1.10
-
-Fixed fd method so that it still returns -1 for in-memory files when db
-1.86 is used.
-
-=item 1.11
-
-Documented the untie gotcha.
-
-=item 1.12
-
-Documented the incompatibility with version 2 of Berkeley DB.
-
-=back
+Moved to the Changes file.
=head1 BUGS
Some older versions of Berkeley DB had problems with fixed length
-records using the RECNO file format. The newest version at the time of
-writing was 1.85 - this seems to have fixed the problems with RECNO.
+records using the RECNO file format. This problem has been fixed since
+version 1.85 of Berkeley DB.
I am sure there are bugs in the code. If you do find any, or can
suggest any enhancements, I would welcome your comments.
=head1 AVAILABILITY
B<DB_File> comes with the standard Perl source distribution. Look in
-the directory F<ext/DB_File>.
+the directory F<ext/DB_File>. Given the amount of time between releases
+of Perl the version that ships with Perl is quite likely to be out of
+date, so the most recent version can always be found on CPAN (see
+L<perlmod/CPAN> for details), in the directory
+F<modules/by-module/DB_File>.
-This version of B<DB_File> will only work with version 1.x of Berkeley
-DB. It is I<not> yet compatible with version 2.
+This version of B<DB_File> will work with either version 1.x or 2.x of
+Berkeley DB, but is limited to the functionality provided by version 1.
-Version 1 of Berkeley DB is available at your nearest CPAN archive (see
-L<perlmod/"CPAN"> for a list) in F<src/misc/db.1.85.tar.gz>, or via the
-host F<ftp.cs.berkeley.edu> in F</ucb/4bsd/db.tar.gz>. Alternatively,
-check out the Berkeley DB home page at F<http://www.bostic.com/db>. It
-is I<not> under the GPL.
+The official web site for Berkeley DB is
+F<http://www.sleepycat.com/db>. The ftp equivalent is
+F<ftp.sleepycat.com:/pub>. Both versions 1 and 2 of Berkeley DB are
+available there.
-If you are running IRIX, then get Berkeley DB from
+Alternatively, Berkeley DB version 1 is available at your nearest CPAN
+archive in F<src/misc/db.1.85.tar.gz>.
+
+If you are running IRIX, then get Berkeley DB version 1 from
F<http://reality.sgi.com/ariel>. It has the patches necessary to
compile properly on IRIX 5.3.
-As of January 1997, version 1.86 of Berkeley DB is available from the
-Berkeley DB home page. Although this release does fix a number of bugs
-that were present in 1.85 you should be aware of the following
-information (taken from the Berkeley DB home page) before you consider
-using it:
+=head1 COPYRIGHT
+
+Copyright (c) 1995-8 Paul Marquess. All rights reserved. This program
+is free software; you can redistribute it and/or modify it under the
+same terms as Perl itself.
+
+Although B<DB_File> is covered by the Perl license, the library it
+makes use of, namely Berkeley DB, is not. Berkeley DB has its own
+copyright and its own license. Please take the time to read it.
+
+Here are are few words taken from the Berkeley DB FAQ (at
+http://www.sleepycat.com) regarding the license:
+
+ Do I have to license DB to use it in Perl scripts?
- DB version 1.86 includes a new implementation of the hash access
- method that fixes a variety of hashing problems found in DB version
- 1.85. We are making it available as an interim solution until DB
- 2.0 is available.
+ No. The Berkeley DB license requires that software that uses
+ Berkeley DB be freely redistributable. In the case of Perl, that
+ software is Perl, and not your scripts. Any Perl scripts that you
+ write are your property, including scripts that make use of
+ Berkeley DB. Neither the Perl license nor the Berkeley DB license
+ place any restriction on what you may do with them.
- PLEASE NOTE: the underlying file format for the hash access method
- changed between version 1.85 and version 1.86, so you will have to
- dump and reload all of your databases to convert from version 1.85
- to version 1.86. If you do not absolutely require the fixes from
- version 1.86, we strongly urge you to wait until DB 2.0 is released
- before upgrading from 1.85.
+If you are in any doubt about the license situation, contact either the
+Berkeley DB authors or the author of DB_File. See L<"AUTHOR"> for details.
=head1 SEE ALSO
The DB_File interface was written by Paul Marquess
E<lt>pmarquess@bfsec.bt.co.ukE<gt>.
-Questions about the DB system itself may be addressed to Keith Bostic
-E<lt>bostic@cs.berkeley.eduE<gt>.
+Questions about the DB system itself may be addressed to
+E<lt>db@sleepycat.com<gt>.
=cut
projects / p5sagit/p5-mst-13.2.git / blobdiff