[dbsrgits/DBM-Deep.git] / lib / DBM / Deep.pm

package DBM::Deep;

use 5.006_000;

use strict;
use warnings;

our $VERSION = q(1.0008);

use Fcntl qw( :flock );

use Digest::MD5 ();
use FileHandle::Fmode ();
use Scalar::Util ();

use DBM::Deep::Engine;
use DBM::Deep::File;

use overload
    '""' => sub { overload::StrVal( $_[0] ) },
    fallback => 1;

##
# Setup constants for users to pass to new()
##
sub TYPE_HASH   () { DBM::Deep::Engine->SIG_HASH  }
sub TYPE_ARRAY  () { DBM::Deep::Engine->SIG_ARRAY }

# This is used in all the children of this class in their TIE<type> methods.
sub _get_args {
    my $proto = shift;

    my $args;
    if (scalar(@_) > 1) {
        if ( @_ % 2 ) {
            $proto->_throw_error( "Odd number of parameters to " . (caller(1))[2] );
        }
        $args = {@_};
    }
    elsif ( ref $_[0] ) {
        unless ( eval { local $SIG{'__DIE__'}; %{$_[0]} || 1 } ) {
            $proto->_throw_error( "Not a hashref in args to " . (caller(1))[2] );
        }
        $args = $_[0];
    }
    else {
        $args = { file => shift };
    }

    return $args;
}

sub new {
    ##
    # Class constructor method for Perl OO interface.
    # Calls tie() and returns blessed reference to tied hash or array,
    # providing a hybrid OO/tie interface.
    ##
    my $class = shift;
    my $args = $class->_get_args( @_ );

    ##
    # Check if we want a tied hash or array.
    ##
    my $self;
    if (defined($args->{type}) && $args->{type} eq TYPE_ARRAY) {
        $class = 'DBM::Deep::Array';
        require DBM::Deep::Array;
        tie @$self, $class, %$args;
    }
    else {
        $class = 'DBM::Deep::Hash';
        require DBM::Deep::Hash;
        tie %$self, $class, %$args;
    }

    return bless $self, $class;
}

# This initializer is called from the various TIE* methods. new() calls tie(),
# which allows for a single point of entry.
sub _init {
    my $class = shift;
    my ($args) = @_;

    $args->{storage} = DBM::Deep::File->new( $args )
        unless exists $args->{storage};

    # locking implicitly enables autoflush
    if ($args->{locking}) { $args->{autoflush} = 1; }

    # These are the defaults to be optionally overridden below
    my $self = bless {
        type        => TYPE_HASH,
        base_offset => undef,
        staleness   => undef,

        storage     => undef,
        engine      => undef,
    }, $class;

    $args->{engine} = DBM::Deep::Engine->new( { %{$args}, obj => $self } )
        unless exists $args->{engine};

    # Grab the parameters we want to use
    foreach my $param ( keys %$self ) {
        next unless exists $args->{$param};
        $self->{$param} = $args->{$param};
    }

    eval {
      local $SIG{'__DIE__'};

      $self->lock;
      $self->_engine->setup_fh( $self );
      $self->_storage->set_inode;
      $self->unlock;
    }; if ( $@ ) {
      my $e = $@;
      eval { local $SIG{'__DIE__'}; $self->unlock; };
      die $e;
    }

    return $self;
}

sub TIEHASH {
    shift;
    require DBM::Deep::Hash;
    return DBM::Deep::Hash->TIEHASH( @_ );
}

sub TIEARRAY {
    shift;
    require DBM::Deep::Array;
    return DBM::Deep::Array->TIEARRAY( @_ );
}

sub lock {
    my $self = shift->_get_self;
    return $self->_storage->lock( $self, @_ );
}

sub unlock {
    my $self = shift->_get_self;
    return $self->_storage->unlock( $self, @_ );
}

sub _copy_value {
    my $self = shift->_get_self;
    my ($spot, $value) = @_;

    if ( !ref $value ) {
        ${$spot} = $value;
    }
    elsif ( eval { local $SIG{__DIE__}; $value->isa( 'DBM::Deep' ) } ) {
        ${$spot} = $value->_repr;
        $value->_copy_node( ${$spot} );
    }
    else {
        my $r = Scalar::Util::reftype( $value );
        my $c = Scalar::Util::blessed( $value );
        if ( $r eq 'ARRAY' ) {
            ${$spot} = [ @{$value} ];
        }
        else {
            ${$spot} = { %{$value} };
        }
        ${$spot} = bless ${$spot}, $c
            if defined $c;
    }

    return 1;
}

#sub _copy_node {
#    die "Must be implemented in a child class\n";
#}
#
#sub _repr {
#    die "Must be implemented in a child class\n";
#}

sub export {
    ##
    # Recursively export into standard Perl hashes and arrays.
    ##
    my $self = shift->_get_self;

    my $temp = $self->_repr;

    $self->lock();
    $self->_copy_node( $temp );
    $self->unlock();

    my $classname = $self->_engine->get_classname( $self );
    if ( defined $classname ) {
      bless $temp, $classname;
    }

    return $temp;
}

sub _check_legality {
    my $self = shift;
    my ($val) = @_;

    my $r = Scalar::Util::reftype( $val );

    return $r if !defined $r || '' eq $r;
    return $r if 'HASH' eq $r;
    return $r if 'ARRAY' eq $r;

    DBM::Deep->_throw_error(
        "Storage of references of type '$r' is not supported."
    );
}

sub import {
    # Perl calls import() on use -- ignore
    return if !ref $_[0];

    my $self = shift->_get_self;
    my ($struct) = @_;

    my $type = $self->_check_legality( $struct );
    if ( !$type ) {
        DBM::Deep->_throw_error( "Cannot import a scalar" );
    }

    if ( substr( $type, 0, 1 ) ne $self->_type ) {
        DBM::Deep->_throw_error(
            "Cannot import " . ('HASH' eq $type ? 'a hash' : 'an array')
            . " into " . ('HASH' eq $type ? 'an array' : 'a hash')
        );
    }

    my %seen;
    my $recurse;
    $recurse = sub {
        my ($db, $val) = @_;

        my $obj = 'HASH' eq Scalar::Util::reftype( $db ) ? tied(%$db) : tied(@$db);
        $obj ||= $db;

        my $r = $self->_check_legality( $val );
        if ( 'HASH' eq $r ) {
            while ( my ($k, $v) = each %$val ) {
                my $r = $self->_check_legality( $v );
                if ( $r ) {
                    my $temp = 'HASH' eq $r ? {} : [];
                    if ( my $c = Scalar::Util::blessed( $v ) ) {
                        bless $temp, $c;
                    }
                    $obj->put( $k, $temp );
                    $recurse->( $temp, $v );
                }
                else {
                    $obj->put( $k, $v );
                }
            }
        }
        elsif ( 'ARRAY' eq $r ) {
            foreach my $k ( 0 .. $#$val ) {
                my $v = $val->[$k];
                my $r = $self->_check_legality( $v );
                if ( $r ) {
                    my $temp = 'HASH' eq $r ? {} : [];
                    if ( my $c = Scalar::Util::blessed( $v ) ) {
                        bless $temp, $c;
                    }
                    $obj->put( $k, $temp );
                    $recurse->( $temp, $v );
                }
                else {
                    $obj->put( $k, $v );
                }
            }
        }
    };
    $recurse->( $self, $struct );

    return 1;
}

#XXX Need to keep track of who has a fh to this file in order to
#XXX close them all prior to optimize on Win32/cygwin
sub optimize {
    ##
    # Rebuild entire database into new file, then move
    # it back on top of original.
    ##
    my $self = shift->_get_self;

#XXX Need to create a new test for this
#    if ($self->_storage->{links} > 1) {
#        $self->_throw_error("Cannot optimize: reference count is greater than 1");
#    }

    #XXX Do we have to lock the tempfile?

    #XXX Should we use tempfile() here instead of a hard-coded name?
    my $db_temp = DBM::Deep->new(
        file => $self->_storage->{file} . '.tmp',
        type => $self->_type,

        # Bring over all the parameters that we need to bring over
        ( map { $_ => $self->_engine->$_ } qw(
            byte_size max_buckets data_sector_size num_txns
        )),
    );

    $self->lock();
    $self->_engine->clear_cache;
    $self->_copy_node( $db_temp );
    undef $db_temp;

    ##
    # Attempt to copy user, group and permissions over to new file
    ##
    my @stats = stat($self->_fh);
    my $perms = $stats[2] & 07777;
    my $uid = $stats[4];
    my $gid = $stats[5];
    chown( $uid, $gid, $self->_storage->{file} . '.tmp' );
    chmod( $perms, $self->_storage->{file} . '.tmp' );

    # q.v. perlport for more information on this variable
    if ( $^O eq 'MSWin32' || $^O eq 'cygwin' ) {
        ##
        # Potential race condition when optmizing on Win32 with locking.
        # The Windows filesystem requires that the filehandle be closed
        # before it is overwritten with rename().  This could be redone
        # with a soft copy.
        ##
        $self->unlock();
        $self->_storage->close;
    }

    if (!rename $self->_storage->{file} . '.tmp', $self->_storage->{file}) {
        unlink $self->_storage->{file} . '.tmp';
        $self->unlock();
        $self->_throw_error("Optimize failed: Cannot copy temp file over original: $!");
    }

    $self->unlock();
    $self->_storage->close;

    $self->_storage->open;
    $self->lock();
    $self->_engine->setup_fh( $self );
    $self->unlock();

    return 1;
}

sub clone {
    ##
    # Make copy of object and return
    ##
    my $self = shift->_get_self;

    return DBM::Deep->new(
        type        => $self->_type,
        base_offset => $self->_base_offset,
        staleness   => $self->_staleness,
        storage     => $self->_storage,
        engine      => $self->_engine,
    );
}

#XXX Migrate this to the engine, where it really belongs and go through some
# API - stop poking in the innards of someone else..
{
    my %is_legal_filter = map {
        $_ => ~~1,
    } qw(
        store_key store_value
        fetch_key fetch_value
    );

    sub set_filter {
        my $self = shift->_get_self;
        my $type = lc shift;
        my $func = shift;

        if ( $is_legal_filter{$type} ) {
            $self->_storage->{"filter_$type"} = $func;
            return 1;
        }

        return;
    }

    sub filter_store_key   { $_[0]->set_filter( store_key   => $_[1] ); }
    sub filter_store_value { $_[0]->set_filter( store_value => $_[1] ); }
    sub filter_fetch_key   { $_[0]->set_filter( fetch_key   => $_[1] ); }
    sub filter_fetch_value { $_[0]->set_filter( fetch_value => $_[1] ); }
}

sub begin_work {
    my $self = shift->_get_self;
    return $self->_engine->begin_work( $self, @_ );
}

sub rollback {
    my $self = shift->_get_self;
    return $self->_engine->rollback( $self, @_ );
}

sub commit {
    my $self = shift->_get_self;
    return $self->_engine->commit( $self, @_ );
}

##
# Accessor methods
##

sub _engine {
    my $self = $_[0]->_get_self;
    return $self->{engine};
}

sub _storage {
    my $self = $_[0]->_get_self;
    return $self->{storage};
}

sub _type {
    my $self = $_[0]->_get_self;
    return $self->{type};
}

sub _base_offset {
    my $self = $_[0]->_get_self;
    return $self->{base_offset};
}

sub _staleness {
    my $self = $_[0]->_get_self;
    return $self->{staleness};
}

sub _fh {
    my $self = $_[0]->_get_self;
    return $self->_storage->{fh};
}

##
# Utility methods
##

sub _throw_error {
    my $n = 0;
    while( 1 ) {
        my @caller = caller( ++$n );
        next if $caller[0] =~ m/^DBM::Deep/;

        die "DBM::Deep: $_[1] at $0 line $caller[2]\n";
    }
}

sub STORE {
    ##
    # Store single hash key/value or array element in database.
    ##
    my $self = shift->_get_self;
    my ($key, $value) = @_;

    if ( !FileHandle::Fmode::is_W( $self->_fh ) ) {
        $self->_throw_error( 'Cannot write to a readonly filehandle' );
    }

    ##
    # Request exclusive lock for writing
    ##
    $self->lock( LOCK_EX );

    # User may be storing a complex value, in which case we do not want it run
    # through the filtering system.
    if ( !ref($value) && $self->_storage->{filter_store_value} ) {
        $value = $self->_storage->{filter_store_value}->( $value );
    }

    $self->_engine->write_value( $self, $key, $value);

    $self->unlock();

    return 1;
}

sub FETCH {
    ##
    # Fetch single value or element given plain key or array index
    ##
    my $self = shift->_get_self;
    my ($key) = @_;

    ##
    # Request shared lock for reading
    ##
    $self->lock( LOCK_SH );

    my $result = $self->_engine->read_value( $self, $key);

    $self->unlock();

    # Filters only apply to scalar values, so the ref check is making
    # sure the fetched bucket is a scalar, not a child hash or array.
    return ($result && !ref($result) && $self->_storage->{filter_fetch_value})
        ? $self->_storage->{filter_fetch_value}->($result)
        : $result;
}

sub DELETE {
    ##
    # Delete single key/value pair or element given plain key or array index
    ##
    my $self = shift->_get_self;
    my ($key) = @_;

    if ( !FileHandle::Fmode::is_W( $self->_fh ) ) {
        $self->_throw_error( 'Cannot write to a readonly filehandle' );
    }

    ##
    # Request exclusive lock for writing
    ##
    $self->lock( LOCK_EX );

    ##
    # Delete bucket
    ##
    my $value = $self->_engine->delete_key( $self, $key);

    if (defined $value && !ref($value) && $self->_storage->{filter_fetch_value}) {
        $value = $self->_storage->{filter_fetch_value}->($value);
    }

    $self->unlock();

    return $value;
}

sub EXISTS {
    ##
    # Check if a single key or element exists given plain key or array index
    ##
    my $self = shift->_get_self;
    my ($key) = @_;

    ##
    # Request shared lock for reading
    ##
    $self->lock( LOCK_SH );

    my $result = $self->_engine->key_exists( $self, $key );

    $self->unlock();

    return $result;
}

sub CLEAR {
    ##
    # Clear all keys from hash, or all elements from array.
    ##
    my $self = shift->_get_self;

    if ( !FileHandle::Fmode::is_W( $self->_fh ) ) {
        $self->_throw_error( 'Cannot write to a readonly filehandle' );
    }

    ##
    # Request exclusive lock for writing
    ##
    $self->lock( LOCK_EX );

    #XXX Rewrite this dreck to do it in the engine as a tight loop vs.
    # iterating over keys - such a WASTE - is this required for transactional
    # clearning?! Surely that can be detected in the engine ...
    if ( $self->_type eq TYPE_HASH ) {
        my $key = $self->first_key;
        while ( $key ) {
            # Retrieve the key before deleting because we depend on next_key
            my $next_key = $self->next_key( $key );
            $self->_engine->delete_key( $self, $key, $key );
            $key = $next_key;
        }
    }
    else {
        my $size = $self->FETCHSIZE;
        for my $key ( 0 .. $size - 1 ) {
            $self->_engine->delete_key( $self, $key, $key );
        }
        $self->STORESIZE( 0 );
    }

    $self->unlock();

    return 1;
}

##
# Public method aliases
##
sub put { (shift)->STORE( @_ ) }
sub store { (shift)->STORE( @_ ) }
sub get { (shift)->FETCH( @_ ) }
sub fetch { (shift)->FETCH( @_ ) }
sub delete { (shift)->DELETE( @_ ) }
sub exists { (shift)->EXISTS( @_ ) }
sub clear { (shift)->CLEAR( @_ ) }

sub _dump_file {shift->_get_self->_engine->_dump_file;}

1;
__END__
Commit	Line	Data
ffed8b01	1	package DBM::Deep;
ffed8b01	2
2120a181	3	use 5.006_000;
460b1067	4
ffed8b01	5	use strict;
460b1067	6	use warnings;
8b957036	7
45f047f8	8	our $VERSION = q(1.0008);
86867f3a	9
2120a181	10	use Fcntl qw( :flock );
12b96196	11
ffed8b01	12	use Digest::MD5 ();
a8fdabda	13	use FileHandle::Fmode ();
ffed8b01	14	use Scalar::Util ();
ffed8b01	15
2120a181	16	use DBM::Deep::Engine;
460b1067	17	use DBM::Deep::File;
95967a5e	18
c57b19c6	19	use overload
	20	'""' => sub { overload::StrVal( $_[0] ) },
	21	fallback => 1;
	22
ffed8b01	23	##
	24	# Setup constants for users to pass to new()
	25	##
2120a181	26	sub TYPE_HASH () { DBM::Deep::Engine->SIG_HASH }
2120a181	27	sub TYPE_ARRAY () { DBM::Deep::Engine->SIG_ARRAY }
ffed8b01	28
2120a181	29	# This is used in all the children of this class in their TIE<type> methods.
0ca7ea98	30	sub _get_args {
	31	my $proto = shift;
	32
	33	my $args;
	34	if (scalar(@_) > 1) {
	35	if ( @_ % 2 ) {
	36	$proto->_throw_error( "Odd number of parameters to " . (caller(1))[2] );
	37	}
	38	$args = {@_};
	39	}
d0b74c17	40	elsif ( ref $_[0] ) {
4d35d856	41	unless ( eval { local $SIG{'__DIE__'}; %{$_[0]} \|\| 1 } ) {
0ca7ea98	42	$proto->_throw_error( "Not a hashref in args to " . (caller(1))[2] );
	43	}
	44	$args = $_[0];
	45	}
d0b74c17	46	else {
0ca7ea98	47	$args = { file => shift };
	48	}
	49
	50	return $args;
	51	}
	52
ffed8b01	53	sub new {
d0b74c17	54	##
	55	# Class constructor method for Perl OO interface.
	56	# Calls tie() and returns blessed reference to tied hash or array,
	57	# providing a hybrid OO/tie interface.
	58	##
	59	my $class = shift;
	60	my $args = $class->_get_args( @_ );
	61
	62	##
	63	# Check if we want a tied hash or array.
	64	##
	65	my $self;
	66	if (defined($args->{type}) && $args->{type} eq TYPE_ARRAY) {
6fe26b29	67	$class = 'DBM::Deep::Array';
6fe26b29	68	require DBM::Deep::Array;
d0b74c17	69	tie @$self, $class, %$args;
	70	}
	71	else {
6fe26b29	72	$class = 'DBM::Deep::Hash';
6fe26b29	73	require DBM::Deep::Hash;
d0b74c17	74	tie %$self, $class, %$args;
d0b74c17	75	}
ffed8b01	76
d0b74c17	77	return bless $self, $class;
ffed8b01	78	}
ffed8b01	79
96041a25	80	# This initializer is called from the various TIE* methods. new() calls tie(),
96041a25	81	# which allows for a single point of entry.
0795f290	82	sub _init {
0795f290	83	my $class = shift;
994ccd8e	84	my ($args) = @_;
0795f290	85
83371fe3	86	$args->{storage} = DBM::Deep::File->new( $args )
83371fe3	87	unless exists $args->{storage};
460b1067	88
	89	# locking implicitly enables autoflush
	90	if ($args->{locking}) { $args->{autoflush} = 1; }
	91
0795f290	92	# These are the defaults to be optionally overridden below
0795f290	93	my $self = bless {
95967a5e	94	type => TYPE_HASH,
e06824f8	95	base_offset => undef,
2120a181	96	staleness => undef,
359a01ac	97
83371fe3	98	storage => undef,
2120a181	99	engine => undef,
0795f290	100	}, $class;
2120a181	101
	102	$args->{engine} = DBM::Deep::Engine->new( { %{$args}, obj => $self } )
	103	unless exists $args->{engine};
8db25060	104
fde3db1a	105	# Grab the parameters we want to use
0795f290	106	foreach my $param ( keys %$self ) {
0795f290	107	next unless exists $args->{$param};
3e9498a1	108	$self->{$param} = $args->{$param};
ffed8b01	109	}
d0b74c17	110
2120a181	111	eval {
2120a181	112	local $SIG{'__DIE__'};
0795f290	113
2120a181	114	$self->lock;
	115	$self->_engine->setup_fh( $self );
	116	$self->_storage->set_inode;
	117	$self->unlock;
	118	}; if ( $@ ) {
	119	my $e = $@;
	120	eval { local $SIG{'__DIE__'}; $self->unlock; };
	121	die $e;
	122	}
359a01ac	123
0795f290	124	return $self;
ffed8b01	125	}
ffed8b01	126
ffed8b01	127	sub TIEHASH {
6fe26b29	128	shift;
	129	require DBM::Deep::Hash;
	130	return DBM::Deep::Hash->TIEHASH( @_ );
ffed8b01	131	}
	132
	133	sub TIEARRAY {
6fe26b29	134	shift;
	135	require DBM::Deep::Array;
	136	return DBM::Deep::Array->TIEARRAY( @_ );
ffed8b01	137	}
ffed8b01	138
ffed8b01	139	sub lock {
994ccd8e	140	my $self = shift->_get_self;
83371fe3	141	return $self->_storage->lock( $self, @_ );
ffed8b01	142	}
	143
	144	sub unlock {
994ccd8e	145	my $self = shift->_get_self;
83371fe3	146	return $self->_storage->unlock( $self, @_ );
ffed8b01	147	}
ffed8b01	148
906c8e01	149	sub _copy_value {
	150	my $self = shift->_get_self;
	151	my ($spot, $value) = @_;
	152
	153	if ( !ref $value ) {
	154	${$spot} = $value;
	155	}
	156	elsif ( eval { local $SIG{__DIE__}; $value->isa( 'DBM::Deep' ) } ) {
f9c33187	157	${$spot} = $value->_repr;
906c8e01	158	$value->_copy_node( ${$spot} );
	159	}
	160	else {
	161	my $r = Scalar::Util::reftype( $value );
	162	my $c = Scalar::Util::blessed( $value );
	163	if ( $r eq 'ARRAY' ) {
	164	${$spot} = [ @{$value} ];
	165	}
	166	else {
	167	${$spot} = { %{$value} };
	168	}
95bbd935	169	${$spot} = bless ${$spot}, $c
906c8e01	170	if defined $c;
	171	}
	172
	173	return 1;
	174	}
	175
2120a181	176	#sub _copy_node {
	177	# die "Must be implemented in a child class\n";
	178	#}
	179	#
	180	#sub _repr {
	181	# die "Must be implemented in a child class\n";
	182	#}
ffed8b01	183
ffed8b01	184	sub export {
d0b74c17	185	##
	186	# Recursively export into standard Perl hashes and arrays.
	187	##
994ccd8e	188	my $self = shift->_get_self;
d0b74c17	189
f9c33187	190	my $temp = $self->_repr;
d0b74c17	191
	192	$self->lock();
	193	$self->_copy_node( $temp );
	194	$self->unlock();
	195
2120a181	196	my $classname = $self->_engine->get_classname( $self );
	197	if ( defined $classname ) {
	198	bless $temp, $classname;
68f943b3	199	}
68f943b3	200
d0b74c17	201	return $temp;
ffed8b01	202	}
ffed8b01	203
e00d0eb3	204	sub _check_legality {
	205	my $self = shift;
	206	my ($val) = @_;
	207
	208	my $r = Scalar::Util::reftype( $val );
	209
	210	return $r if !defined $r \|\| '' eq $r;
	211	return $r if 'HASH' eq $r;
	212	return $r if 'ARRAY' eq $r;
	213
	214	DBM::Deep->_throw_error(
	215	"Storage of references of type '$r' is not supported."
	216	);
	217	}
	218
ffed8b01	219	sub import {
e00d0eb3	220	# Perl calls import() on use -- ignore
e00d0eb3	221	return if !ref $_[0];
d0b74c17	222
994ccd8e	223	my $self = shift->_get_self;
994ccd8e	224	my ($struct) = @_;
d0b74c17	225
e00d0eb3	226	my $type = $self->_check_legality( $struct );
	227	if ( !$type ) {
	228	DBM::Deep->_throw_error( "Cannot import a scalar" );
d0b74c17	229	}
d0b74c17	230
e00d0eb3	231	if ( substr( $type, 0, 1 ) ne $self->_type ) {
	232	DBM::Deep->_throw_error(
	233	"Cannot import " . ('HASH' eq $type ? 'a hash' : 'an array')
	234	. " into " . ('HASH' eq $type ? 'an array' : 'a hash')
	235	);
7a960a12	236	}
7a960a12	237
e00d0eb3	238	my %seen;
	239	my $recurse;
	240	$recurse = sub {
	241	my ($db, $val) = @_;
	242
	243	my $obj = 'HASH' eq Scalar::Util::reftype( $db ) ? tied(%$db) : tied(@$db);
	244	$obj \|\|= $db;
	245
	246	my $r = $self->_check_legality( $val );
	247	if ( 'HASH' eq $r ) {
	248	while ( my ($k, $v) = each %$val ) {
	249	my $r = $self->_check_legality( $v );
	250	if ( $r ) {
	251	my $temp = 'HASH' eq $r ? {} : [];
	252	if ( my $c = Scalar::Util::blessed( $v ) ) {
	253	bless $temp, $c;
	254	}
	255	$obj->put( $k, $temp );
	256	$recurse->( $temp, $v );
	257	}
	258	else {
	259	$obj->put( $k, $v );
	260	}
	261	}
	262	}
	263	elsif ( 'ARRAY' eq $r ) {
	264	foreach my $k ( 0 .. $#$val ) {
	265	my $v = $val->[$k];
	266	my $r = $self->_check_legality( $v );
	267	if ( $r ) {
	268	my $temp = 'HASH' eq $r ? {} : [];
	269	if ( my $c = Scalar::Util::blessed( $v ) ) {
	270	bless $temp, $c;
	271	}
	272	$obj->put( $k, $temp );
	273	$recurse->( $temp, $v );
	274	}
	275	else {
	276	$obj->put( $k, $v );
	277	}
	278	}
	279	}
	280	};
	281	$recurse->( $self, $struct );
	282
7a960a12	283	return 1;
ffed8b01	284	}
ffed8b01	285
13ff93d5	286	#XXX Need to keep track of who has a fh to this file in order to
13ff93d5	287	#XXX close them all prior to optimize on Win32/cygwin
ffed8b01	288	sub optimize {
d0b74c17	289	##
	290	# Rebuild entire database into new file, then move
	291	# it back on top of original.
	292	##
994ccd8e	293	my $self = shift->_get_self;
cc4bef86	294
cc4bef86	295	#XXX Need to create a new test for this
83371fe3	296	# if ($self->_storage->{links} > 1) {
1400a48e	297	# $self->_throw_error("Cannot optimize: reference count is greater than 1");
d0b74c17	298	# }
d0b74c17	299
7a960a12	300	#XXX Do we have to lock the tempfile?
7a960a12	301
e00d0eb3	302	#XXX Should we use tempfile() here instead of a hard-coded name?
d0b74c17	303	my $db_temp = DBM::Deep->new(
83371fe3	304	file => $self->_storage->{file} . '.tmp',
2120a181	305	type => $self->_type,
	306
	307	# Bring over all the parameters that we need to bring over
888453b9	308	( map { $_ => $self->_engine->$_ } qw(
	309	byte_size max_buckets data_sector_size num_txns
	310	)),
d0b74c17	311	);
d0b74c17	312
d0b74c17	313	$self->lock();
c57b19c6	314	$self->_engine->clear_cache;
d0b74c17	315	$self->_copy_node( $db_temp );
	316	undef $db_temp;
	317
	318	##
	319	# Attempt to copy user, group and permissions over to new file
	320	##
	321	my @stats = stat($self->_fh);
	322	my $perms = $stats[2] & 07777;
	323	my $uid = $stats[4];
	324	my $gid = $stats[5];
83371fe3	325	chown( $uid, $gid, $self->_storage->{file} . '.tmp' );
83371fe3	326	chmod( $perms, $self->_storage->{file} . '.tmp' );
d0b74c17	327
ffed8b01	328	# q.v. perlport for more information on this variable
90f93b43	329	if ( $^O eq 'MSWin32' \|\| $^O eq 'cygwin' ) {
d0b74c17	330	##
	331	# Potential race condition when optmizing on Win32 with locking.
	332	# The Windows filesystem requires that the filehandle be closed
	333	# before it is overwritten with rename(). This could be redone
	334	# with a soft copy.
	335	##
	336	$self->unlock();
83371fe3	337	$self->_storage->close;
d0b74c17	338	}
d0b74c17	339
83371fe3	340	if (!rename $self->_storage->{file} . '.tmp', $self->_storage->{file}) {
83371fe3	341	unlink $self->_storage->{file} . '.tmp';
d0b74c17	342	$self->unlock();
1400a48e	343	$self->_throw_error("Optimize failed: Cannot copy temp file over original: $!");
d0b74c17	344	}
	345
	346	$self->unlock();
83371fe3	347	$self->_storage->close;
2120a181	348
83371fe3	349	$self->_storage->open;
2120a181	350	$self->lock();
72e315ac	351	$self->_engine->setup_fh( $self );
2120a181	352	$self->unlock();
70b55428	353
d0b74c17	354	return 1;
ffed8b01	355	}
	356
	357	sub clone {
d0b74c17	358	##
	359	# Make copy of object and return
	360	##
994ccd8e	361	my $self = shift->_get_self;
d0b74c17	362
d0b74c17	363	return DBM::Deep->new(
c3aafc14	364	type => $self->_type,
d0b74c17	365	base_offset => $self->_base_offset,
2120a181	366	staleness => $self->_staleness,
83371fe3	367	storage => $self->_storage,
2120a181	368	engine => $self->_engine,
d0b74c17	369	);
ffed8b01	370	}
ffed8b01	371
2120a181	372	#XXX Migrate this to the engine, where it really belongs and go through some
2120a181	373	# API - stop poking in the innards of someone else..
ffed8b01	374	{
	375	my %is_legal_filter = map {
	376	$_ => ~~1,
	377	} qw(
	378	store_key store_value
	379	fetch_key fetch_value
	380	);
	381
	382	sub set_filter {
994ccd8e	383	my $self = shift->_get_self;
	384	my $type = lc shift;
	385	my $func = shift;
d0b74c17	386
ffed8b01	387	if ( $is_legal_filter{$type} ) {
83371fe3	388	$self->_storage->{"filter_$type"} = $func;
ffed8b01	389	return 1;
	390	}
	391
	392	return;
	393	}
888453b9	394
	395	sub filter_store_key { $_[0]->set_filter( store_key => $_[1] ); }
	396	sub filter_store_value { $_[0]->set_filter( store_value => $_[1] ); }
	397	sub filter_fetch_key { $_[0]->set_filter( fetch_key => $_[1] ); }
	398	sub filter_fetch_value { $_[0]->set_filter( fetch_value => $_[1] ); }
ffed8b01	399	}
ffed8b01	400
fee0243f	401	sub begin_work {
fee0243f	402	my $self = shift->_get_self;
2120a181	403	return $self->_engine->begin_work( $self, @_ );
fee0243f	404	}
	405
	406	sub rollback {
	407	my $self = shift->_get_self;
2120a181	408	return $self->_engine->rollback( $self, @_ );
fee0243f	409	}
fee0243f	410
359a01ac	411	sub commit {
359a01ac	412	my $self = shift->_get_self;
2120a181	413	return $self->_engine->commit( $self, @_ );
359a01ac	414	}
fee0243f	415
ffed8b01	416	##
	417	# Accessor methods
	418	##
	419
72e315ac	420	sub _engine {
	421	my $self = $_[0]->_get_self;
	422	return $self->{engine};
	423	}
	424
83371fe3	425	sub _storage {
2ac02042	426	my $self = $_[0]->_get_self;
83371fe3	427	return $self->{storage};
ffed8b01	428	}
ffed8b01	429
4d35d856	430	sub _type {
2ac02042	431	my $self = $_[0]->_get_self;
d0b74c17	432	return $self->{type};
ffed8b01	433	}
ffed8b01	434
4d35d856	435	sub _base_offset {
2ac02042	436	my $self = $_[0]->_get_self;
d0b74c17	437	return $self->{base_offset};
ffed8b01	438	}
ffed8b01	439
2120a181	440	sub _staleness {
	441	my $self = $_[0]->_get_self;
	442	return $self->{staleness};
	443	}
	444
994ccd8e	445	sub _fh {
994ccd8e	446	my $self = $_[0]->_get_self;
83371fe3	447	return $self->_storage->{fh};
994ccd8e	448	}
994ccd8e	449
ffed8b01	450	##
	451	# Utility methods
	452	##
	453
261d1296	454	sub _throw_error {
807f63a7	455	my $n = 0;
	456	while( 1 ) {
	457	my @caller = caller( ++$n );
	458	next if $caller[0] =~ m/^DBM::Deep/;
	459
	460	die "DBM::Deep: $_[1] at $0 line $caller[2]\n";
807f63a7	461	}
ffed8b01	462	}
ffed8b01	463
ffed8b01	464	sub STORE {
d0b74c17	465	##
	466	# Store single hash key/value or array element in database.
	467	##
	468	my $self = shift->_get_self;
2120a181	469	my ($key, $value) = @_;
81d3d316	470
a8fdabda	471	if ( !FileHandle::Fmode::is_W( $self->_fh ) ) {
acd4faf2	472	$self->_throw_error( 'Cannot write to a readonly filehandle' );
acd4faf2	473	}
d0b74c17	474
	475	##
	476	# Request exclusive lock for writing
	477	##
	478	$self->lock( LOCK_EX );
	479
0cb639bd	480	# User may be storing a complex value, in which case we do not want it run
0cb639bd	481	# through the filtering system.
83371fe3	482	if ( !ref($value) && $self->_storage->{filter_store_value} ) {
83371fe3	483	$value = $self->_storage->{filter_store_value}->( $value );
d0b74c17	484	}
d0b74c17	485
2120a181	486	$self->_engine->write_value( $self, $key, $value);
d0b74c17	487
	488	$self->unlock();
	489
86867f3a	490	return 1;
ffed8b01	491	}
	492
	493	sub FETCH {
d0b74c17	494	##
	495	# Fetch single value or element given plain key or array index
	496	##
cb79ec85	497	my $self = shift->_get_self;
2120a181	498	my ($key) = @_;
ffed8b01	499
d0b74c17	500	##
	501	# Request shared lock for reading
	502	##
	503	$self->lock( LOCK_SH );
	504
2120a181	505	my $result = $self->_engine->read_value( $self, $key);
d0b74c17	506
	507	$self->unlock();
	508
a86430bd	509	# Filters only apply to scalar values, so the ref check is making
a86430bd	510	# sure the fetched bucket is a scalar, not a child hash or array.
83371fe3	511	return ($result && !ref($result) && $self->_storage->{filter_fetch_value})
83371fe3	512	? $self->_storage->{filter_fetch_value}->($result)
cb79ec85	513	: $result;
ffed8b01	514	}
	515
	516	sub DELETE {
d0b74c17	517	##
	518	# Delete single key/value pair or element given plain key or array index
	519	##
a97c8f67	520	my $self = shift->_get_self;
2120a181	521	my ($key) = @_;
d0b74c17	522
a8fdabda	523	if ( !FileHandle::Fmode::is_W( $self->_fh ) ) {
a86430bd	524	$self->_throw_error( 'Cannot write to a readonly filehandle' );
a86430bd	525	}
d0b74c17	526
	527	##
	528	# Request exclusive lock for writing
	529	##
	530	$self->lock( LOCK_EX );
	531
d0b74c17	532	##
	533	# Delete bucket
	534	##
2120a181	535	my $value = $self->_engine->delete_key( $self, $key);
a86430bd	536
83371fe3	537	if (defined $value && !ref($value) && $self->_storage->{filter_fetch_value}) {
83371fe3	538	$value = $self->_storage->{filter_fetch_value}->($value);
3b6a5056	539	}
3b6a5056	540
d0b74c17	541	$self->unlock();
	542
	543	return $value;
ffed8b01	544	}
	545
	546	sub EXISTS {
d0b74c17	547	##
	548	# Check if a single key or element exists given plain key or array index
	549	##
a97c8f67	550	my $self = shift->_get_self;
a97c8f67	551	my ($key) = @_;
d0b74c17	552
d0b74c17	553	##
	554	# Request shared lock for reading
	555	##
	556	$self->lock( LOCK_SH );
	557
2120a181	558	my $result = $self->_engine->key_exists( $self, $key );
d0b74c17	559
	560	$self->unlock();
	561
	562	return $result;
ffed8b01	563	}
	564
	565	sub CLEAR {
d0b74c17	566	##
	567	# Clear all keys from hash, or all elements from array.
	568	##
a97c8f67	569	my $self = shift->_get_self;
ffed8b01	570
a8fdabda	571	if ( !FileHandle::Fmode::is_W( $self->_fh ) ) {
a86430bd	572	$self->_throw_error( 'Cannot write to a readonly filehandle' );
	573	}
	574
d0b74c17	575	##
	576	# Request exclusive lock for writing
	577	##
	578	$self->lock( LOCK_EX );
	579
2120a181	580	#XXX Rewrite this dreck to do it in the engine as a tight loop vs.
	581	# iterating over keys - such a WASTE - is this required for transactional
	582	# clearning?! Surely that can be detected in the engine ...
f9a320bb	583	if ( $self->_type eq TYPE_HASH ) {
	584	my $key = $self->first_key;
	585	while ( $key ) {
83c43bb5	586	# Retrieve the key before deleting because we depend on next_key
f9a320bb	587	my $next_key = $self->next_key( $key );
2120a181	588	$self->_engine->delete_key( $self, $key, $key );
f9a320bb	589	$key = $next_key;
	590	}
	591	}
	592	else {
	593	my $size = $self->FETCHSIZE;
c3aafc14	594	for my $key ( 0 .. $size - 1 ) {
2120a181	595	$self->_engine->delete_key( $self, $key, $key );
f9a320bb	596	}
	597	$self->STORESIZE( 0 );
	598	}
d0b74c17	599
	600	$self->unlock();
	601
	602	return 1;
ffed8b01	603	}
ffed8b01	604
ffed8b01	605	##
	606	# Public method aliases
	607	##
7f441181	608	sub put { (shift)->STORE( @_ ) }
	609	sub store { (shift)->STORE( @_ ) }
	610	sub get { (shift)->FETCH( @_ ) }
	611	sub fetch { (shift)->FETCH( @_ ) }
baa27ab6	612	sub delete { (shift)->DELETE( @_ ) }
	613	sub exists { (shift)->EXISTS( @_ ) }
	614	sub clear { (shift)->CLEAR( @_ ) }
ffed8b01	615
888453b9	616	sub _dump_file {shift->_get_self->_engine->_dump_file;}
888453b9	617
ffed8b01	618	1;
ffed8b01	619	__END__