On 22.09.2012 12:23, H.Merijn Brand wrote:
> On Wed, 19 Sep 2012 17:21:32 +0200, Jens Rehsack <[email protected]>
> wrote:
>
>> Hi Merijn,
>>
>> while hacking around in DBD::File and DBI::DBD::SqlEngine I stumbled
>> over a major design fault made in the past:
>
> Some - backward compatible - thoughts:
>
> Replace all dir-related parts in DBD::File with callbacks
>
> Make streaming interfaces able to override dir-related parts
>
> Backward compatible AND extendable
First shot attached as committed (svn revert for the win ^^).
Needs some additional tests for streams as well as pod updates.
>> sub DBD::File::Table::get_table_meta () ... evaluates
>> $dbh->{f_meta}{$table}{initialized} and does something magic else. This
>> magic is fully DBD::File addicted (heavily relies on file2table) and it
>> should be broken into separate pieces to differ between initialisation
>> done for DBI::DBD::SqlEngine and DBD::File and DBD::DBM ...
>>
>> I'd like to discuss it tomorrow in IRC (but I read my e-Mail if you have
>> comments at the evening).
>>
>> If anyone else has ideas - please feel free to speak (but primary
>> restriction is backward compatibility to avoid breakage of dependent DBD's).
>>
>> Best regards,
>> Jens
Best regards,
Jens
Index: lib/DBI/DBD/SqlEngine.pm
===================================================================
--- lib/DBI/DBD/SqlEngine.pm (Revision 15395)
+++ lib/DBI/DBD/SqlEngine.pm (Arbeitskopie)
@@ -206,6 +206,24 @@
return $dbh;
} # connect
+sub data_sources ($;$)
+{
+ my ( $drh, $attr ) = @_;
+
+ my $tbl_src;
+ $attr
+ and defined $attr->{sql_table_source}
+ and $attr->{sql_table_source}->isa('DBI::DBD::SqlEngine::TableSource')
+ and $tbl_src = $attr->{sql_table_source};
+
+ !defined($tbl_src)
+ and $drh->can('default_table_source')
+ and $tbl_src = $drh->default_table_source();
+ defined($tbl_src) or return;
+
+ $tbl_src->data_sources( $drh, $attr );
+} # data_sources
+
sub disconnect_all
{
} # disconnect_all
@@ -243,6 +261,15 @@
( $_[0]->FETCH("Active") ) ? 1 : 0;
} # ping
+sub data_sources
+{
+ my ( $dbh, $attr, @other ) = @_;
+ my $drh = $dbh->{Driver}; # XXX proxy issues?
+ ref($attr) eq 'HASH' or $attr = {};
+ defined( $attr->{sql_table_source} ) or $attr->{sql_table_source} =
$dbh->{sql_table_source};
+ return $drh->data_sources( $attr, @other );
+}
+
sub prepare ($$;@)
{
my ( $dbh, $statement, @attribs ) = @_;
@@ -834,12 +861,23 @@
if ( $dbh->{sql_handler} eq "SQL::Statement" and $dbh->{sql_ram_tables} )
{
+ # XXX map +[ undef, undef, $_, "TABLE", "TEMP" ], keys %{...}
foreach my $table ( keys %{ $dbh->{sql_ram_tables} } )
{
push @tables, [ undef, undef, $table, "TABLE", "TEMP" ];
}
}
+ my $tbl_src;
+ defined $dbh->{sql_table_source}
+ and $dbh->{sql_table_source}->isa('DBI::DBD::SqlEngine::TableSource')
+ and $tbl_src = $dbh->{sql_table_source};
+
+ !defined($tbl_src)
+ and $dbh->{Driver}->{ImplementorClass}->can('default_table_source')
+ and $tbl_src =
$dbh->{Driver}->{ImplementorClass}->default_table_source();
+ defined($tbl_src) and push( @tables, $tbl_src->avail_tables($dbh) );
+
return @tables;
} # get_avail_tables
@@ -1269,6 +1307,48 @@
return $_[0]->{sql_stmt}{NUM_OF_ROWS};
} # rows
+# ====== TableSource
===========================================================
+
+package DBI::DBD::SqlEngine::TableSource;
+
+use strict;
+use warnings;
+
+use Carp;
+
+sub data_sources ($;$)
+{
+ my ( $class, $drh, $attrs ) = @_;
+ croak( ( ref( $_[0] ) ? ref( $_[0] ) : $_[0] ) . " must implement
data_sources" );
+}
+
+sub avail_tables
+{
+ my ( $self, $dbh ) = @_;
+ croak( ( ref( $_[0] ) ? ref( $_[0] ) : $_[0] ) . " must implement
avail_tables" );
+}
+
+# ====== DataSource
============================================================
+
+package DBI::DBD::SqlEngine::DataSource;
+
+use strict;
+use warnings;
+
+use Carp;
+
+sub complete_table_name ($$;$)
+{
+ my ( $self, $meta, $table, $respect_case ) = @_;
+ croak( ( ref( $_[0] ) ? ref( $_[0] ) : $_[0] ) . " must implement
complete_table_name" );
+}
+
+sub open_data ($)
+{
+ my ( $self, $meta, $attrs, $flags ) = @_;
+ croak( ( ref( $_[0] ) ? ref( $_[0] ) : $_[0] ) . " must implement
open_data" );
+}
+
# ====== SQL::STATEMENT
========================================================
package DBI::DBD::SqlEngine::Statement;
@@ -1332,24 +1412,22 @@
and $meta->{readonly} = $dbh->{ReadOnly};
defined $meta->{sql_identifier_case}
or $meta->{sql_identifier_case} = $dbh->{sql_identifier_case};
+
+ exists $meta->{sql_data_source} or $meta->{sql_data_source} =
$dbh->{sql_data_source};
+
+ $meta;
}
sub init_table_meta
{
- my ( $self, $dbh, $meta, $table ) = @_;
+ my ( $self, $dbh, $meta, $table ) = @_ if(0);
return;
} # init_table_meta
-our $respect_table_case;
-sub respect_case { $respect_table_case }
-
-our $bootstrap_table_meta_phase = 0;
-sub bootstrap_table_meta_phase { $bootstrap_table_meta_phase }
-
sub get_table_meta ($$$;$)
{
- my ( $self, $dbh, $table, $respect_case ) = @_;
+ my ( $self, $dbh, $table, $respect_case, @other ) = @_;
unless ( defined $respect_case )
{
$respect_case = 0;
@@ -1367,12 +1445,10 @@
unless ( $meta->{initialized} )
{
- local $bootstrap_table_meta_phase = 1;
- local $respect_table_case = $respect_case;
+ $self->bootstrap_table_meta( $dbh, $meta, $table, @other );
+ $meta->{sql_data_source}->complete_table_name( $meta, $table,
$respect_case, @other )
+ or return;
- $self->bootstrap_table_meta( $dbh, $meta, $table );
- return unless $meta->{table_name};
-
if ( defined $meta->{table_name} and $table ne $meta->{table_name} )
{
$dbh->{sql_meta_map}{$table} = $meta->{table_name};
@@ -1384,13 +1460,9 @@
if ( defined $dbh->{sql_meta}{$table} && defined
$dbh->{sql_meta}{$table}{initialized} )
{
$meta = $dbh->{sql_meta}{$table};
-
- unless ( $dbh->{sql_meta}{$table}{initialized} )
- {
- $bootstrap_table_meta_phase = 2;
- $self->bootstrap_table_meta( $dbh, $meta, $table );
- $meta->{table_name} or return;
- }
+ $dbh->{sql_meta}{$table}{initialized}
+ or $meta->{sql_data_source}->complete_table_name( $dbh, $meta,
$table, $respect_case, @other )
+ or return;
}
unless ( $dbh->{sql_meta}{$table}{initialized} )
Index: lib/DBD/File.pm
===================================================================
--- lib/DBD/File.pm (Revision 15396)
+++ lib/DBD/File.pm (Arbeitskopie)
@@ -97,35 +97,9 @@
return $str;
} # dsn_quote
-sub data_sources ($;$)
-{
- my ($drh, $attr) = @_;
- my $dir = $attr && exists $attr->{f_dir}
- ? $attr->{f_dir}
- : File::Spec->curdir ();
- defined $dir or return; # Stream-based databases do not have f_dir
- my %attrs;
- $attr and %attrs = %$attr;
- delete $attrs{f_dir};
- my $dsnextra = join ";", map { $_ . "=" . dsn_quote ($attrs{$_}) } keys
%attrs;
- my ($dirh) = Symbol::gensym ();
- unless (opendir $dirh, $dir) {
- $drh->set_err ($DBI::stderr, "Cannot open directory $dir: $!");
- return;
- }
+# XXX rewrite using TableConfig ...
+sub default_table_source { 'DBD::File::TableSource::FileSystem' }
- my ($file, @dsns, %names, $driver);
- $driver = $drh->{ImplementorClass} =~ m/^dbd\:\:([^\:]+)\:\:/i ? $1 :
"File";
-
- while (defined ($file = readdir ($dirh))) {
- my $d = File::Spec->catdir ($dir, $file);
- # allow current dir ... it can be a data_source too
- $file ne File::Spec->updir () && -d $d and
- push @dsns, "DBI:$driver:f_dir=" . dsn_quote ($d) . ($dsnextra ?
";$dsnextra" : "");
- }
- return @dsns;
- } # data_sources
-
sub disconnect_all
{
} # disconnect_all
@@ -152,6 +126,14 @@
@DBD::File::db::ISA = qw(DBI::DBD::SqlEngine::db);
$DBD::File::db::imp_data_size = 0;
+sub data_sources
+{
+ my ($dbh, $attr, @other) = @_;
+ ref($attr) eq 'HASH' or $attr = {};
+ exists($attr->{f_dir}) or $attr->{f_dir} = $dbh->{f_dir};
+ return $dbh->SUPER::data_sources($attr, @other);
+}
+
sub set_versions
{
my $dbh = shift;
@@ -204,7 +186,7 @@
# f_map is deprecated (but might return)
$dbh->{f_dir} = Cwd::abs_path (File::Spec->curdir ());
- if(0) {
+ if(0) { # XXX remove block
# complete derived attributes, if required
(my $drv_class = $dbh->{ImplementorClass}) =~ s/::db$//;
my $drv_prefix = DBI->driver_prefix ($drv_class);
@@ -273,40 +255,6 @@
return sprintf "%s using %s", $dbh->{f_version}, $dtype;
} # get_f_versions
-sub get_avail_tables
-{
- my $dbh = shift;
-
- my @tables = $dbh->SUPER::get_avail_tables ();
- my $dir = $dbh->{f_dir};
- defined $dir or return; # Stream based db's cannot be queried for tables
- my $dirh = Symbol::gensym ();
-
- unless (opendir $dirh, $dir) {
- $dbh->set_err ($DBI::stderr, "Cannot open directory $dir: $!");
- return @tables;
- }
-
- my $class = $dbh->FETCH ("ImplementorClass");
- $class =~ s/::db$/::Table/;
- my ($file, %names);
- my $schema = exists $dbh->{f_schema}
- ? defined $dbh->{f_schema} && $dbh->{f_schema} ne ""
- ? $dbh->{f_schema} : undef
- : eval { getpwuid ((stat $dir)[4]) }; # XXX Win32::pwent
- my %seen;
- while (defined ($file = readdir ($dirh))) {
- my ($tbl, $meta) = $class->get_table_meta ($dbh, $file, 0, 0) or next;
# XXX
- # $tbl && $meta && -f $meta->{f_fqfn} or next;
- $seen{defined $schema ? $schema : "\0"}{$tbl}++ or
- push @tables, [ undef, $schema, $tbl, "TABLE", "FILE" ];
- }
- closedir $dirh or
- $dbh->set_err ($DBI::stderr, "Cannot close directory $dir: $!");
-
- return @tables;
- } # get_avail_tables
-
# ====== STATEMENT
=============================================================
package DBD::File::st;
@@ -369,51 +317,179 @@
return $sth->SUPER::FETCH ($attr);
} # FETCH
-# ====== SQL::STATEMENT
========================================================
+# ====== TableSource
===========================================================
-package DBD::File::Statement;
+package DBD::File::TableSource::FileSystem;
use strict;
use warnings;
-@DBD::File::Statement::ISA = qw( DBI::DBD::SqlEngine::Statement );
+use IO::Dir;
-# ====== SQL::TABLE
============================================================
+@DBD::File::TableSource::FileSystem::ISA = 'DBI::DBD::SqlEngine::TableSource';
-package DBD::File::Table;
+sub data_sources
+{
+ my ($class, $drh, $attr) = @_;
+ my $dir = $attr && exists $attr->{f_dir}
+ ? $attr->{f_dir}
+ : File::Spec->curdir ();
+ defined $dir or return; # Stream-based databases do not have f_dir
+ my %attrs;
+ $attr and %attrs = %$attr;
+ delete $attrs{f_dir};
+ my $dsn_quote = $drh->can("dsn_quote");
+ my $dsnextra = join ";", map { $_ . "=" . &{$dsn_quote} ($attrs{$_}) }
keys %attrs;
+ my $dirh = IO::Dir->new($dir);
+ unless (defined $dirh) {
+ $drh->set_err ($DBI::stderr, "Cannot open directory $dir: $!");
+ return;
+ }
+ my ($file, @dsns, %names, $driver);
+ $driver = $drh->{ImplementorClass} =~ m/^dbd\:\:([^\:]+)\:\:/i ? $1 :
"File";
+
+ while (defined ($file = $dirh->read())) {
+ my $d = File::Spec->catdir ($dir, $file);
+ # allow current dir ... it can be a data_source too
+ $file ne File::Spec->updir () && -d $d and
+ push @dsns, "DBI:$driver:f_dir=" . dsn_quote ($d) . ($dsnextra ?
";$dsnextra" : "");
+ }
+ return @dsns;
+ } # data_sources
+
+sub avail_tables
+{
+ my ($self, $dbh) = @_;
+
+ my $dir = $dbh->{f_dir};
+ defined $dir or return; # Stream based db's cannot be queried for tables
+ my $dirh = IO::Dir->new($dir);
+
+ unless (defined $dirh) {
+ $dbh->set_err ($DBI::stderr, "Cannot open directory $dir: $!");
+ return;
+ }
+
+ my $class = $dbh->FETCH ("ImplementorClass");
+ $class =~ s/::db$/::Table/;
+ my ($file, %names);
+ my $schema = exists $dbh->{f_schema}
+ ? defined $dbh->{f_schema} && $dbh->{f_schema} ne ""
+ ? $dbh->{f_schema} : undef
+ : eval { getpwuid ((stat $dir)[4]) }; # XXX Win32::pwent
+ my %seen;
+ my @tables;
+ while (defined ($file = $dirh->read ())) {
+ my ($tbl, $meta) = $class->get_table_meta ($dbh, $file, 0, 0) or next;
# XXX
+ # $tbl && $meta && -f $meta->{f_fqfn} or next;
+ $seen{defined $schema ? $schema : "\0"}{$tbl}++ or
+ push @tables, [ undef, $schema, $tbl, "TABLE", "FILE" ];
+ }
+ $dirh->close() or
+ $dbh->set_err ($DBI::stderr, "Cannot close directory $dir: $!");
+
+ return @tables;
+ }
+
+# ====== DataSource
============================================================
+
+package DBD::File::DataSource::Stream;
+
use strict;
use warnings;
+@DBD::File::DataSource::Stream::ISA = 'DBI::DBD::SqlEngine::DataSource';
+
use Carp;
-require IO::File;
-require File::Basename;
-require File::Spec;
-require Cwd;
-# We may have a working flock () built-in but that doesn't mean that locking
-# will work on NFS (flock () may hang hard)
-my $locking = eval { flock STDOUT, 0; 1 };
+sub complete_table_name
+{
+ my ($self, $meta, $file, $respect_case) = @_;
-@DBD::File::Table::ISA = qw( DBI::DBD::SqlEngine::Table );
+ my $tbl;
+ if (!$respect_case and $meta->{sql_identifier_case} == 1) { # XXX
SQL_IC_UPPER
+ $tbl = uc $tbl;
+ }
+ elsif (!$respect_case and $meta->{sql_identifier_case} == 2) { # XXX
SQL_IC_LOWER
+ $tbl = lc $tbl;
+ }
-# ====== FLYWEIGHT SUPPORT
=====================================================
+ $meta->{f_fqfn} = undef;
+ $meta->{f_fqbn} = undef;
+ $meta->{f_fqln} = undef;
+ $meta->{table_name} = $tbl;
+
+ return $tbl;
+ } # complete_table_name
+
+sub apply_encoding
+{
+ my ($self, $meta, $fn) = @_;
+ defined($fn) or $fn = "file handle " . fileno($meta->{fh});
+ if (my $enc = $meta->{f_encoding}) {
+ binmode $meta->{fh}, ":encoding($enc)" or
+ croak "Failed to set encoding layer '$enc' on $fn: $!";
+ }
+ else {
+ binmode $meta->{fh} or croak "Failed to set binary mode on $fn: $!";
+ }
+ } # apply_encoding
+
+sub open_data
+{
+ my ($self, $meta, $attrs, $flags) = @_;
+
+ $flags->{dropMode} and croak "Can't drop a table in stream";
+ my $fn = "file handle " . fileno($meta->{fh});
+
+ if ($flags->{createMode} || $flags->{lockMode}) {
+ $meta->{fh} = IO::Handle->new_from_fd( fileno($meta->{f_file} ), "w+" )
or
+ croak "Cannot open $fn for writing: $! (" . ($!+0) . ")";
+ }
+ else {
+ $meta->{fh} = IO::Handle->new_from_fd( fileno($meta->{f_file} ), "r" )
or
+ croak "Cannot open $fn for reading: $! (" . ($!+0) . ")";
+ }
+
+ $meta->{fh} = $meta->{f_file};
+ if ($meta->{fh}) {
+ if (my $enc = $meta->{f_encoding}) {
+ binmode $meta->{fh}, ":encoding($enc)" or
+ croak "Failed to set encoding layer '$enc' on $fn: $!";
+ }
+ else {
+ binmode $meta->{fh} or croak "Failed to set binary mode on $fn: $!";
+ }
+ } # have $meta->{$fh}
+ } # open_data
+
+package DBD::File::DataSource::File;
+
+use strict;
+use warnings;
+
+@DBD::File::DataSource::File::ISA = 'DBD::File::DataSource::Stream';
+
+use Carp;
+
my $fn_any_ext_regex = qr/\.[^.]*/;
-# Flyweight support for table_info
-# The functions file2table, init_table_meta, default_table_meta and
-# get_table_meta are using $self arguments for polymorphism only. The
-# must not rely on an instantiated DBD::File::Table
-sub file2table
+# We may have a working flock () built-in but that doesn't mean that locking
+# will work on NFS (flock () may hang hard)
+my $locking = eval { flock STDOUT, 0; 1 };
+
+sub complete_table_name
{
- my ($self, $meta, $file, $file_is_table, $respect_case) = @_;
+ my ($self, $meta, $file, $respect_case, $file_is_table) = @_;
$file eq "." || $file eq ".." and return; # XXX would break a
possible DBD::Dir
+ # XXX now called without proving f_fqfn first ...
my ($ext, $req) = ("", 0);
if ($meta->{f_ext}) {
- ($ext, my $opt) = split m/\//, $meta->{f_ext};
+ ($ext, my $opt) = split m{/}, $meta->{f_ext};
if ($ext && $opt) {
$opt =~ m/r/i and $req = 1;
}
@@ -437,7 +513,7 @@
$basename = uc $basename;
$tbl = uc $tbl;
}
- if( !$respect_case and $meta->{sql_identifier_case} == 2) { # XXX
SQL_IC_LOWER
+ elsif (!$respect_case and $meta->{sql_identifier_case} == 2) { # XXX
SQL_IC_LOWER
$basename = lc $basename;
$tbl = lc $tbl;
}
@@ -475,12 +551,15 @@
}
}
- opendir my $dh, $searchdir or croak "Can't open '$searchdir': $!";
- my @f = sort { length $b <=> length $a } grep { &$cmpsub ($_) } readdir
$dh;
+ my @f;
+ {
+ my $dh = IO::Dir->new ($searchdir) or croak "Can't open
'$searchdir': $!";
+ @f = sort { length $b <=> length $a } grep { &$cmpsub ($_) }
$dh->read();
+ $dh->close() or croak "Can't close '$searchdir': $!";
+ }
@f > 0 && @f <= 2 and $file = $f[0];
!$respect_case && $meta->{sql_identifier_case} == 4 and # XXX
SQL_IC_MIXED
($tbl = $file) =~ s/$ext$//i;
- closedir $dh or croak "Can't close '$searchdir': $!";
my $tmpfn = $file;
if ($ext && $req) {
@@ -501,60 +580,11 @@
$meta->{table_name} = $tbl;
return $tbl;
- } # file2table
+ } # complete_table_name
-sub bootstrap_table_meta
-{
- my ($self, $dbh, $meta, $table) = @_;
- $self->SUPER::bootstrap_table_meta($dbh, $meta, $table);
-
- exists $meta->{f_dir} or $meta->{f_dir} = $dbh->{f_dir};
- defined $meta->{f_ext} or $meta->{f_ext} = $dbh->{f_ext};
- defined $meta->{f_encoding} or $meta->{f_encoding} =
$dbh->{f_encoding};
- exists $meta->{f_lock} or $meta->{f_lock} = $dbh->{f_lock};
- exists $meta->{f_lockfile} or $meta->{f_lockfile} =
$dbh->{f_lockfile};
- defined $meta->{f_schema} or $meta->{f_schema} = $dbh->{f_schema};
-
- if ($self->bootstrap_table_meta_phase == 2 or !defined $meta->{f_fqfn}) {
- $self->file2table ($meta, $table, $self->file_is_table,
$self->respect_case) or delete $meta->{table_name};
- }
-
- } # bootstrap_table_meta
-
-our $file_is_a_table;
-sub file_is_table { $file_is_a_table }
-
-sub get_table_meta ($$$$;$)
+sub open_data
{
- my ($self, $dbh, $table, $file_is_table, $respect_case) = @_;
-
- local $file_is_a_table = $file_is_table;
- my $meta = $self->SUPER::get_table_meta($dbh, $table, $respect_case);
- $table = $meta->{table_name};
- return unless $table;
-
- return ($table, $meta);
- } # get_table_meta
-
-my %reset_on_modify = (
- f_file => "f_fqfn",
- f_dir => "f_fqfn",
- f_ext => "f_fqfn",
- f_lockfile => "f_fqfn", # forces new file2table call
- );
-
-__PACKAGE__->register_reset_on_modify( \%reset_on_modify );
-
-my %compat_map = map { $_ => "f_$_" } qw( file ext lock lockfile );
-
-__PACKAGE__->register_compat_map( \%compat_map );
-
-
-# ====== FILE OPEN
=============================================================
-
-sub open_file ($$$)
-{
my ($self, $meta, $attrs, $flags) = @_;
defined $meta->{f_fqfn} && $meta->{f_fqfn} ne "" or croak "No filename
given";
@@ -574,19 +604,14 @@
}
}
+ $meta->{fh} = $fh;
+
if ($fh) {
$fh->seek (0, 0) or
croak "Error while seeking back: $!";
- if (my $enc = $meta->{f_encoding}) {
- binmode $fh, ":encoding($enc)" or
- croak "Failed to set encoding layer '$enc' on $fn: $!";
- }
- else {
- binmode $fh or croak "Failed to set binary mode on $fn: $!";
- }
+
+ $self->apply_encoding($meta);
}
-
- $meta->{fh} = $fh;
}
if ($meta->{f_fqln}) {
$fn = $meta->{f_fqln};
@@ -618,8 +643,131 @@
}
# $lm = 0 is forced no locking at all
}
- } # open_file
+ }
+# ====== SQL::STATEMENT
========================================================
+
+package DBD::File::Statement;
+
+use strict;
+use warnings;
+
+@DBD::File::Statement::ISA = qw( DBI::DBD::SqlEngine::Statement );
+
+# ====== SQL::TABLE
============================================================
+
+package DBD::File::Table;
+
+use strict;
+use warnings;
+
+use Carp;
+require IO::File;
+require File::Basename;
+require File::Spec;
+require Cwd;
+require Scalar::Util;
+
+@DBD::File::Table::ISA = qw( DBI::DBD::SqlEngine::Table );
+
+# ====== UTILITIES ============================================================
+
+if ( eval { require Params::Util; } )
+{
+ Params::Util->import("_HANDLE");
+}
+else
+{
+ # taken but modified from Params::Util ...
+ *_HANDLE = sub {
+ # It has to be defined, of course
+ defined $_[0] or return;
+
+ # Normal globs are considered to be file handles
+ ref $_[0] eq 'GLOB' and return $_[0];
+
+ # Check for a normal tied filehandle
+ # Side Note: 5.5.4's tied() and can() doesn't like getting undef
+ tied($_[0]) and tied($_[0])->can('TIEHANDLE') and return $_[0];
+
+ # There are no other non-object handles that we support
+ Scalar::Util::blessed($_[0]) or return;
+
+ # Check for a common base classes for conventional IO::Handle object
+ $_[0]->isa('IO::Handle') and return $_[0];
+
+ # Check for tied file handles using Tie::Handle
+ $_[0]->isa('Tie::Handle') and return $_[0];
+
+ # IO::Scalar is not a proper seekable, but it is valid is a
+ # regular file handle
+ $_[0]->isa('IO::Scalar') and return $_[0];
+
+ # Yet another special case for IO::String, which refuses (for now
+ # anyway) to become a subclass of IO::Handle.
+ $_[0]->isa('IO::String') and return $_[0];
+
+ # This is not any sort of object we know about
+ return;
+ };
+}
+
+# ====== FLYWEIGHT SUPPORT
=====================================================
+
+# Flyweight support for table_info
+# The functions file2table, init_table_meta, default_table_meta and
+# get_table_meta are using $self arguments for polymorphism only. The
+# must not rely on an instantiated DBD::File::Table
+sub file2table
+{
+ my ($self, $meta, $file, $file_is_table, $respect_case) = @_;
+
+ return $meta->{sql_data_source}->complete_table_name($meta, $file,
$respect_case, $file_is_table);
+ } # file2table
+
+sub bootstrap_table_meta
+{
+ my ($self, $dbh, $meta, $table, @other) = @_;
+
+ $self->SUPER::bootstrap_table_meta($dbh, $meta, $table, @other);
+
+ exists $meta->{f_dir} or $meta->{f_dir} = $dbh->{f_dir};
+ defined $meta->{f_ext} or $meta->{f_ext} = $dbh->{f_ext};
+ defined $meta->{f_encoding} or $meta->{f_encoding} =
$dbh->{f_encoding};
+ exists $meta->{f_lock} or $meta->{f_lock} = $dbh->{f_lock};
+ exists $meta->{f_lockfile} or $meta->{f_lockfile} =
$dbh->{f_lockfile};
+ defined $meta->{f_schema} or $meta->{f_schema} = $dbh->{f_schema};
+
+ defined ($meta->{sql_data_source}) or
+ $meta->{sql_data_source} = _HANDLE ($meta->{f_file})
+ ? 'DBD::File::DataSource::Stream'
+ : 'DBD::File::DataSource::File';
+ } # bootstrap_table_meta
+
+sub get_table_meta ($$$$;$)
+{
+ my ($self, $dbh, $table, $file_is_table, $respect_case) = @_;
+
+ my $meta = $self->SUPER::get_table_meta($dbh, $table, $respect_case,
$file_is_table);
+ $table = $meta->{table_name};
+ return unless $table;
+
+ return ($table, $meta);
+ } # get_table_meta
+
+my %reset_on_modify = (
+ f_file => "f_fqfn",
+ f_dir => "f_fqfn",
+ f_ext => "f_fqfn",
+ f_lockfile => "f_fqfn", # forces new file2table call
+ );
+
+__PACKAGE__->register_reset_on_modify( \%reset_on_modify );
+
+my %compat_map = map { $_ => "f_$_" } qw( file ext lock lockfile );
+
+__PACKAGE__->register_compat_map( \%compat_map );
+
# ====== SQL::Eval API
=========================================================
sub new
@@ -630,7 +778,7 @@
# because column name mapping is initialized in constructor ...
my ($tblnm, $meta) = $className->get_table_meta ($data->{Database},
$attrs->{table}, 1) or
croak "Cannot find appropriate file for table '$attrs->{table}'";
- $className->open_file ($meta, $attrs, $flags);
+ $meta->{sql_data_source}->open_data ($meta, $attrs, $flags);
return $className->SUPER::new ($data, $attrs, $flags);
} # new
Index: lib/DBD/DBM.pm
===================================================================
--- lib/DBD/DBM.pm (Revision 15390)
+++ lib/DBD/DBM.pm (Arbeitskopie)
@@ -255,17 +255,6 @@
my $dirfext = $^O eq 'VMS' ? '.sdbm_dir' : '.dir';
-sub file2table
-{
- my ( $self, $meta, $file, $file_is_table, $quoted ) = @_;
-
- my $tbl = $self->SUPER::file2table( $meta, $file, $file_is_table, $quoted
) or return;
-
- $meta->{f_dontopen} = 1;
-
- return $tbl;
-}
-
my %reset_on_modify = (
dbm_type => "dbm_tietype",
dbm_mldbm => "dbm_tietype",
@@ -321,6 +310,8 @@
{
my ( $self, $dbh, $meta, $table ) = @_;
+ $meta->{f_dontopen} = 1;
+
unless ( defined( $meta->{dbm_tietype} ) )
{
my $tie_type = $meta->{dbm_type};
