package DBM::Deep::File;
-use 5.6.0;
+use 5.006_000;
use strict;
-use warnings;
+use warnings FATAL => 'all';
use Fcntl qw( :DEFAULT :flock :seek );
-our $VERSION = '0.01';
+use constant DEBUG => 0;
sub new {
my $class = shift;
my ($args) = @_;
my $self = bless {
- autobless => undef,
- autoflush => undef,
+ autobless => 1,
+ autoflush => 1,
end => 0,
fh => undef,
file => undef,
file_offset => 0,
- locking => undef,
+ locking => 1,
locked => 0,
+#XXX Migrate this to the engine, where it really belongs.
filter_store_key => undef,
filter_store_value => undef,
filter_fetch_key => undef,
sub open {
my $self = shift;
- # Adding O_BINARY does remove the need for the binmode below. However,
+ # Adding O_BINARY should remove the need for the binmode below. However,
# I'm not going to remove it because I don't have the Win32 chops to be
# absolutely certain everything will be ok.
- my $flags = O_RDWR | O_CREAT | O_BINARY;
+ my $flags = O_CREAT | O_BINARY;
+
+ if ( !-e $self->{file} || -w _ ) {
+ $flags |= O_RDWR;
+ }
+ else {
+ $flags |= O_RDONLY;
+ }
my $fh;
sysopen( $fh, $self->{file}, $flags )
return 1;
}
+sub size {
+ my $self = shift;
+
+ return 0 unless $self->{fh};
+ return -s $self->{fh};
+}
+
+sub set_inode {
+ my $self = shift;
+
+ unless ( defined $self->{inode} ) {
+ my @stats = stat($self->{fh});
+ $self->{inode} = $stats[1];
+ $self->{end} = $stats[7];
+ }
+
+ return 1;
+}
+
+sub print_at {
+ my $self = shift;
+ my $loc = shift;
+
+ local ($/,$\);
+
+ my $fh = $self->{fh};
+ if ( defined $loc ) {
+ seek( $fh, $loc + $self->{file_offset}, SEEK_SET );
+ }
+
+ if ( DEBUG ) {
+ my $caller = join ':', (caller)[0,2];
+ my $len = length( join '', @_ );
+ warn "($caller) print_at( " . (defined $loc ? $loc : '<undef>') . ", $len )\n";
+ }
+
+ print( $fh @_ ) or die "Internal Error (print_at($loc)): $!\n";
+
+ return 1;
+}
+
+sub read_at {
+ my $self = shift;
+ my ($loc, $size) = @_;
+
+ local ($/,$\);
+
+ my $fh = $self->{fh};
+ if ( defined $loc ) {
+ seek( $fh, $loc + $self->{file_offset}, SEEK_SET );
+ }
+
+ if ( DEBUG ) {
+ my $caller = join ':', (caller)[0,2];
+ warn "($caller) read_at( " . (defined $loc ? $loc : '<undef>') . ", $size )\n";
+ }
+
+ my $buffer;
+ read( $fh, $buffer, $size);
+
+ return $buffer;
+}
+
sub DESTROY {
my $self = shift;
return unless $self;
return;
}
+sub request_space {
+ my $self = shift;
+ my ($size) = @_;
+
+ #XXX Do I need to reset $self->{end} here? I need a testcase
+ my $loc = $self->{end};
+ $self->{end} += $size;
+
+ return $loc;
+}
+
+##
+# If db locking is set, flock() the db file. If called multiple
+# times before unlock(), then the same number of unlocks() must
+# be called before the lock is released.
+##
+sub lock_exclusive {
+ my $self = shift;
+ my ($obj) = @_;
+ return $self->lock( $obj, LOCK_EX );
+}
+
+sub lock_shared {
+ my $self = shift;
+ my ($obj) = @_;
+ return $self->lock( $obj, LOCK_SH );
+}
+
+sub lock {
+ my $self = shift;
+ my ($obj, $type) = @_;
+
+ $type = LOCK_EX unless defined $type;
+
+ #XXX This is a temporary fix for Win32 and autovivification. It
+ # needs to improve somehow. -RobK, 2008-03-09
+ if ( $^O eq 'MSWin32' || $^O eq 'cygwin' ) {
+ $type = LOCK_EX;
+ }
+
+ if (!defined($self->{fh})) { return; }
+
+ #XXX This either needs to allow for upgrading a shared lock to an
+ # exclusive lock or something else with autovivification.
+ # -RobK, 2008-03-09
+ if ($self->{locking}) {
+ if (!$self->{locked}) {
+ flock($self->{fh}, $type);
+
+ # refresh end counter in case file has changed size
+ my @stats = stat($self->{fh});
+ $self->{end} = $stats[7];
+
+ # double-check file inode, in case another process
+ # has optimize()d our file while we were waiting.
+ if (defined($self->{inode}) && $stats[1] != $self->{inode}) {
+ $self->close;
+ $self->open;
+
+ #XXX This needs work
+ $obj->{engine}->setup_fh( $obj );
+
+ flock($self->{fh}, $type); # re-lock
+
+ # This may not be necessary after re-opening
+ $self->{end} = (stat($self->{fh}))[7]; # re-end
+ }
+ }
+ $self->{locked}++;
+
+ return 1;
+ }
+
+ return;
+}
+
+##
+# If db locking is set, unlock the db file. See note in lock()
+# regarding calling lock() multiple times.
+##
+sub unlock {
+ my $self = shift;
+
+ if (!defined($self->{fh})) { return; }
+
+ if ($self->{locking} && $self->{locked} > 0) {
+ $self->{locked}--;
+
+ if (!$self->{locked}) {
+ flock($self->{fh}, LOCK_UN);
+ return 1;
+ }
+
+ return;
+ }
+
+ return;
+}
+
+sub flush {
+ my $self = shift;
+
+ # Flush the filehandle
+ my $old_fh = select $self->{fh};
+ my $old_af = $|; $| = 1; $| = $old_af;
+ select $old_fh;
+
+ return 1;
+}
+
+# Taken from http://www.perlmonks.org/?node_id=691054
+sub is_writable {
+ my $self = shift;
+
+ my $fh = $self->{fh};
+ return unless defined $fh;
+ return unless defined fileno $fh;
+ local $\ = ''; # just in case
+ no warnings; # temporarily disable warnings
+ local $^W; # temporarily disable warnings
+ return print $fh '';
+}
+
+sub copy_stats {
+ my $self = shift;
+ my ($temp_filename) = @_;
+
+ my @stats = stat( $self->{fh} );
+ my $perms = $stats[2] & 07777;
+ my $uid = $stats[4];
+ my $gid = $stats[5];
+ chown( $uid, $gid, $temp_filename );
+ chmod( $perms, $temp_filename );
+}
+
1;
__END__
-
projects / dbsrgits/DBM-Deep.git / blobdiff