package DBM::Deep::Engine;
+use 5.6.0;
+
use strict;
+use warnings;
+
+use Fcntl qw( :DEFAULT :flock );
+use Scalar::Util ();
-use Fcntl qw( :DEFAULT :flock :seek );
+# File-wide notes:
+# * To add to bucket_size, make sure you modify the following:
+# - calculate_sizes()
+# - _get_key_subloc()
+# - add_bucket() - where the buckets are printed
##
# Setup file and tag signatures. These should never change.
##
sub SIG_FILE () { 'DPDB' }
+sub SIG_HEADER () { 'h' }
sub SIG_INTERNAL () { 'i' }
sub SIG_HASH () { 'H' }
sub SIG_ARRAY () { 'A' }
sub SIG_FREE () { 'F' }
sub SIG_SIZE () { 1 }
-sub precalc_sizes {
- ##
- # Precalculate index, bucket and bucket list sizes
- ##
- my $self = shift;
-
- $self->{index_size} = (2**8) * $self->{long_size};
- $self->{bucket_size} = $self->{hash_size} + $self->{long_size} * 2;
- $self->{bucket_list_size} = $self->{max_buckets} * $self->{bucket_size};
-
- return 1;
-}
-
-sub set_pack {
- ##
- # Set pack/unpack modes (see file header for more)
- ##
- my $self = shift;
- my ($long_s, $long_p, $data_s, $data_p) = @_;
-
- ##
- # Set to 4 and 'N' for 32-bit offset tags (default). Theoretical limit of 4
- # GB per file.
- # (Perl must be compiled with largefile support for files > 2 GB)
- #
- # Set to 8 and 'Q' for 64-bit offsets. Theoretical limit of 16 XB per file.
- # (Perl must be compiled with largefile and 64-bit long support)
- ##
- $self->{long_size} = $long_s ? $long_s : 4;
- $self->{long_pack} = $long_p ? $long_p : 'N';
-
- ##
- # Set to 4 and 'N' for 32-bit data length prefixes. Limit of 4 GB for each
- # key/value. Upgrading this is possible (see above) but probably not
- # necessary. If you need more than 4 GB for a single key or value, this
- # module is really not for you :-)
- ##
- $self->{data_size} = $data_s ? $data_s : 4;
- $self->{data_pack} = $data_p ? $data_p : 'N';
-
- return $self->precalc_sizes();
-}
-
-sub set_digest {
- ##
- # Set key digest function (default is MD5)
- ##
- my $self = shift;
- my ($digest_func, $hash_size) = @_;
-
- $self->{digest} = $digest_func ? $digest_func : \&Digest::MD5::md5;
- $self->{hash_size} = $hash_size ? $hash_size : 16;
-
- return $self->precalc_sizes();
-}
-
sub new {
my $class = shift;
my ($args) = @_;
##
# Maximum number of buckets per list before another level of indexing is
- # done.
- # Increase this value for slightly greater speed, but larger database
+ # done. Increase this value for slightly greater speed, but larger database
# files. DO NOT decrease this value below 16, due to risk of recursive
# reindex overrun.
##
max_buckets => 16,
+
+ fileobj => undef,
+ obj => undef,
}, $class;
- $self->precalc_sizes;
+ if ( defined $args->{pack_size} ) {
+ if ( lc $args->{pack_size} eq 'small' ) {
+ $args->{long_size} = 2;
+ $args->{long_pack} = 'n';
+ }
+ elsif ( lc $args->{pack_size} eq 'medium' ) {
+ $args->{long_size} = 4;
+ $args->{long_pack} = 'N';
+ }
+ elsif ( lc $args->{pack_size} eq 'large' ) {
+ $args->{long_size} = 8;
+ $args->{long_pack} = 'Q';
+ }
+ else {
+ die "Unknown pack_size value: '$args->{pack_size}'\n";
+ }
+ }
+
+ # Grab the parameters we want to use
+ foreach my $param ( keys %$self ) {
+ next unless exists $args->{$param};
+ $self->{$param} = $args->{$param};
+ }
+ Scalar::Util::weaken( $self->{obj} ) if $self->{obj};
+
+ if ( $self->{max_buckets} < 16 ) {
+ warn "Floor of max_buckets is 16. Setting it to 16 from '$self->{max_buckets}'\n";
+ $self->{max_buckets} = 16;
+ }
return $self;
}
+sub _fileobj { return $_[0]{fileobj} }
+
+sub calculate_sizes {
+ my $self = shift;
+
+ # The 2**8 here indicates the number of different characters in the
+ # current hashing algorithm
+ #XXX Does this need to be updated with different hashing algorithms?
+ $self->{index_size} = (2**8) * $self->{long_size};
+ $self->{bucket_size} = $self->{hash_size} + $self->{long_size} * 3;
+ $self->{bucket_list_size} = $self->{max_buckets} * $self->{bucket_size};
+
+ return;
+}
+
+sub write_file_header {
+ my $self = shift;
+
+ my $loc = $self->_fileobj->request_space( length( SIG_FILE ) + 21 );
+
+ $self->_fileobj->print_at( $loc,
+ SIG_FILE,
+ SIG_HEADER,
+ pack('N', 1), # header version
+ pack('N', 12), # header size
+ pack('N', 0), # currently running transaction IDs
+ pack('n', $self->{long_size}),
+ pack('A', $self->{long_pack}),
+ pack('n', $self->{data_size}),
+ pack('A', $self->{data_pack}),
+ pack('n', $self->{max_buckets}),
+ );
+
+ $self->_fileobj->set_transaction_offset( 13 );
+
+ return;
+}
+
+sub read_file_header {
+ my $self = shift;
+
+ my $buffer = $self->_fileobj->read_at( 0, length(SIG_FILE) + 9 );
+ return unless length($buffer);
+
+ my ($file_signature, $sig_header, $header_version, $size) = unpack(
+ 'A4 A N N', $buffer
+ );
+
+ unless ( $file_signature eq SIG_FILE ) {
+ $self->_fileobj->close;
+ $self->_throw_error( "Signature not found -- file is not a Deep DB" );
+ }
+
+ unless ( $sig_header eq SIG_HEADER ) {
+ $self->_fileobj->close;
+ $self->_throw_error( "Old file version found." );
+ }
+
+ my $buffer2 = $self->_fileobj->read_at( undef, $size );
+ my ($running_transactions, @values) = unpack( 'N n A n A n', $buffer2 );
+
+ $self->_fileobj->set_transaction_offset( 13 );
+
+ if ( @values < 5 || grep { !defined } @values ) {
+ $self->_fileobj->close;
+ $self->_throw_error("Corrupted file - bad header");
+ }
+
+ #XXX Add warnings if values weren't set right
+ @{$self}{qw(long_size long_pack data_size data_pack max_buckets)} = @values;
+
+ return length($buffer) + length($buffer2);
+}
+
sub setup_fh {
my $self = shift;
my ($obj) = @_;
- $self->open( $obj ) if !defined $obj->_fh;
-
- my $fh = $obj->_fh;
+ # Need to remove use of $fh here
+ my $fh = $self->_fileobj->{fh};
flock $fh, LOCK_EX;
+ #XXX The duplication of calculate_sizes needs to go away
unless ( $obj->{base_offset} ) {
- seek($fh, 0 + $obj->_root->{file_offset}, SEEK_SET);
- my $signature;
- my $bytes_read = read( $fh, $signature, length(SIG_FILE));
+ my $bytes_read = $self->read_file_header;
+
+ $self->calculate_sizes;
##
- # File is empty -- write signature and master index
+ # File is empty -- write header and master index
##
if (!$bytes_read) {
- my $loc = $self->_request_space( $obj, length( SIG_FILE ) );
- seek($fh, $loc + $obj->_root->{file_offset}, SEEK_SET);
- print( $fh SIG_FILE);
+ $self->_fileobj->audit( "# Database created on" );
- $obj->{base_offset} = $self->_request_space(
- $obj, $self->tag_size( $self->{index_size} ),
+ $self->write_file_header;
+
+ $obj->{base_offset} = $self->_fileobj->request_space(
+ $self->tag_size( $self->{index_size} ),
);
$self->write_tag(
- $obj, $obj->_base_offset, $obj->_type,
+ $obj->_base_offset, $obj->_type,
chr(0)x$self->{index_size},
);
$obj->{base_offset} = $bytes_read;
##
- # Check signature was valid
+ # Get our type from master index header
##
- unless ($signature eq SIG_FILE) {
- $self->close_fh( $obj );
- $obj->_throw_error("Signature not found -- file is not a Deep DB");
+ my $tag = $self->load_tag($obj->_base_offset);
+ unless ( $tag ) {
+ flock $fh, LOCK_UN;
+ $self->_throw_error("Corrupted file, no master index record");
}
- ##
- # Get our type from master index signature
- ##
- my $tag = $self->load_tag($obj, $obj->_base_offset)
- or $obj->_throw_error("Corrupted file, no master index record");
-
- unless ($obj->{type} eq $tag->{signature}) {
- $obj->_throw_error("File type mismatch");
+ unless ($obj->_type eq $tag->{signature}) {
+ flock $fh, LOCK_UN;
+ $self->_throw_error("File type mismatch");
}
}
}
+ else {
+ $self->calculate_sizes;
+ }
#XXX We have to make sure we don't mess up when autoflush isn't turned on
- unless ( $obj->_root->{inode} ) {
- my @stats = stat($obj->_fh);
- $obj->_root->{inode} = $stats[1];
- $obj->_root->{end} = $stats[7];
- }
+ $self->_fileobj->set_inode;
flock $fh, LOCK_UN;
return 1;
}
-sub open {
- ##
- # Open a fh to the database, create if nonexistent.
- # Make sure file signature matches DBM::Deep spec.
- ##
- my $self = shift;
- my ($obj) = @_;
-
- # Theoretically, adding O_BINARY should remove the need for the binmode
- # Of course, testing it is going to be ... interesting.
- my $flags = O_RDWR | O_CREAT | O_BINARY;
-
- my $fh;
- my $filename = $obj->_root->{file};
- sysopen( $fh, $filename, $flags )
- or $obj->_throw_error("Cannot sysopen file '$filename': $!");
- $obj->_root->{fh} = $fh;
-
- #XXX Can we remove this by using the right sysopen() flags?
- # Maybe ... q.v. above
- binmode $fh; # for win32
-
- if ($obj->_root->{autoflush}) {
- my $old = select $fh;
- $|=1;
- select $old;
- }
-
- return 1;
-}
-
-sub close_fh {
- my $self = shift;
- my ($obj) = @_;
-
- if ( my $fh = $obj->_root->{fh} ) {
- close $fh;
- }
- $obj->_root->{fh} = undef;
-
- return 1;
-}
-
sub tag_size {
my $self = shift;
my ($size) = @_;
# Given offset, signature and content, create tag and write to disk
##
my $self = shift;
- my ($obj, $offset, $sig, $content) = @_;
+ my ($offset, $sig, $content) = @_;
my $size = length( $content );
- my $fh = $obj->_fh;
-
- if ( defined $offset ) {
- seek($fh, $offset + $obj->_root->{file_offset}, SEEK_SET);
- }
-
- print( $fh $sig . pack($self->{data_pack}, $size) . $content );
+ $self->_fileobj->print_at(
+ $offset,
+ $sig, pack($self->{data_pack}, $size), $content,
+ );
return unless defined $offset;
# Given offset, load single tag and return signature, size and data
##
my $self = shift;
- my ($obj, $offset) = @_;
-
-# print join(':',map{$_||''}caller(1)), $/;
+ my ($offset) = @_;
- my $fh = $obj->_fh;
+ my $fileobj = $self->_fileobj;
- seek($fh, $offset + $obj->_root->{file_offset}, SEEK_SET);
-
- #XXX I'm not sure this check will work if autoflush isn't enabled ...
- return if eof $fh;
-
- my $b;
- read( $fh, $b, SIG_SIZE + $self->{data_size} );
+ my $s = SIG_SIZE + $self->{data_size};
+ my $b = $fileobj->read_at( $offset, $s );
my ($sig, $size) = unpack( "A $self->{data_pack}", $b );
- my $buffer;
- read( $fh, $buffer, $size);
+ my $buffer = $fileobj->read_at( undef, $size );
return {
signature => $sig,
};
}
+sub _get_dbm_object {
+ my $item = shift;
+
+ my $obj = eval {
+ local $SIG{__DIE__};
+ if ($item->isa( 'DBM::Deep' )) {
+ return $item;
+ }
+ return;
+ };
+ return $obj if $obj;
+
+ my $r = Scalar::Util::reftype( $item ) || '';
+ if ( $r eq 'HASH' ) {
+ my $obj = eval {
+ local $SIG{__DIE__};
+ my $obj = tied(%$item);
+ if ($obj->isa( 'DBM::Deep' )) {
+ return $obj;
+ }
+ return;
+ };
+ return $obj if $obj;
+ }
+ elsif ( $r eq 'ARRAY' ) {
+ my $obj = eval {
+ local $SIG{__DIE__};
+ my $obj = tied(@$item);
+ if ($obj->isa( 'DBM::Deep' )) {
+ return $obj;
+ }
+ return;
+ };
+ return $obj if $obj;
+ }
+
+ return;
+}
+
sub _length_needed {
my $self = shift;
- my ($obj, $value, $key) = @_;
+ my ($value, $key) = @_;
my $is_dbm_deep = eval {
local $SIG{'__DIE__'};
$value->isa( 'DBM::Deep' );
};
- my $len = SIG_SIZE + $self->{data_size}
- + $self->{data_size} + length( $key );
+ my $len = SIG_SIZE
+ + $self->{data_size} # size for value
+ + $self->{data_size} # size for key
+ + length( $key ); # length of key
- if ( $is_dbm_deep && $value->_root eq $obj->_root ) {
+ if ( $is_dbm_deep && $value->_fileobj eq $self->_fileobj ) {
+ # long_size is for the internal reference
return $len + $self->{long_size};
}
- my $r = Scalar::Util::reftype( $value ) || '';
- if ( $obj->_root->{autobless} ) {
+ if ( $self->_fileobj->{autobless} ) {
# This is for the bit saying whether or not this thing is blessed.
$len += 1;
}
+ my $r = Scalar::Util::reftype( $value ) || '';
unless ( $r eq 'HASH' || $r eq 'ARRAY' ) {
if ( defined $value ) {
$len += length( $value );
# if autobless is enabled, must also take into consideration
# the class name as it is stored after the key.
- if ( $obj->_root->{autobless} ) {
- my $value_class = Scalar::Util::blessed($value);
- if ( defined $value_class && !$is_dbm_deep ) {
- $len += $self->{data_size} + length($value_class);
+ if ( $self->_fileobj->{autobless} ) {
+ my $c = Scalar::Util::blessed($value);
+ if ( defined $c && !$is_dbm_deep ) {
+ $len += $self->{data_size} + length($c);
}
}
# plain (undigested) key and value.
##
my $self = shift;
- my ($obj, $tag, $md5, $plain_key, $value) = @_;
+ my ($tag, $md5, $plain_key, $value, $deleted, $orig_key) = @_;
+ $deleted ||= 0;
+
+ local($/,$\);
# This verifies that only supported values will be stored.
{
last if $r eq 'HASH';
last if $r eq 'ARRAY';
- $obj->_throw_error(
+ $self->_throw_error(
"Storage of variables of type '$r' is not supported."
);
}
my $location = 0;
my $result = 2;
- my $root = $obj->_root;
- my $fh = $obj->_fh;
+ my $fileobj = $self->_fileobj;
+
+ my $actual_length = $self->_length_needed( $value, $plain_key );
- my $actual_length = $self->_length_needed( $obj, $value, $plain_key );
+ #ACID - This is a mutation. Must only find the exact transaction
+ my ($subloc, $offset, $size,$is_deleted) = $self->_find_in_buckets( $tag, $md5, 1 );
- my ($subloc, $offset, $size) = $self->_find_in_buckets( $tag, $md5 );
+ my @transactions;
+ if ( $fileobj->transaction_id == 0 ) {
+ @transactions = $fileobj->current_transactions;
+ }
-# $self->_release_space( $obj, $size, $subloc );
+# $self->_release_space( $size, $subloc );
# Updating a known md5
#XXX This needs updating to use _release_space
if ( $subloc ) {
$location = $subloc;
}
else {
- $location = $self->_request_space( $obj, $actual_length );
- seek(
- $fh,
- $tag->{offset} + $offset
- + $self->{hash_size} + $root->{file_offset},
- SEEK_SET,
+ $location = $fileobj->request_space( $actual_length );
+
+ $fileobj->print_at( $tag->{offset} + $offset + $self->{hash_size},
+ pack($self->{long_pack}, $location ),
+ pack($self->{long_pack}, $actual_length ),
+ pack('n n', $fileobj->transaction_id, $deleted ),
);
- print( $fh pack($self->{long_pack}, $location ) );
- print( $fh pack($self->{long_pack}, $actual_length ) );
}
}
# Adding a new md5
elsif ( defined $offset ) {
- $location = $self->_request_space( $obj, $actual_length );
+ $location = $fileobj->request_space( $actual_length );
+
+ $fileobj->print_at( $tag->{offset} + $offset,
+ $md5,
+ pack($self->{long_pack}, $location ),
+ pack($self->{long_pack}, $actual_length ),
+ pack('n n', $fileobj->transaction_id, $deleted ),
+ );
- seek( $fh, $tag->{offset} + $offset + $root->{file_offset}, SEEK_SET );
- print( $fh $md5 . pack($self->{long_pack}, $location ) );
- print( $fh pack($self->{long_pack}, $actual_length ) );
+ for ( @transactions ) {
+ my $tag2 = $self->load_tag( $tag->{offset} - SIG_SIZE - $self->{data_size} );
+ $fileobj->{transaction_id} = $_;
+ $self->add_bucket( $tag2, $md5, '', '', 1, $orig_key );
+ $fileobj->{transaction_id} = 0;
+ }
+ $tag = $self->load_tag( $tag->{offset} - SIG_SIZE - $self->{data_size} );
}
# If bucket didn't fit into list, split into a new index level
- # split_index() will do the _request_space() call
+ # split_index() will do the _fileobj->request_space() call
else {
- $location = $self->split_index( $obj, $md5, $tag );
+ $location = $self->split_index( $md5, $tag );
}
- $self->write_value( $obj, $location, $plain_key, $value );
+ $self->write_value( $location, $plain_key, $value, $orig_key );
return $result;
}
sub write_value {
my $self = shift;
- my ($obj, $location, $key, $value) = @_;
-
- my $fh = $obj->_fh;
- my $root = $obj->_root;
-
- my $is_dbm_deep = eval {
- local $SIG{'__DIE__'};
- $value->isa( 'DBM::Deep' );
- };
+ my ($location, $key, $value, $orig_key) = @_;
- my $is_internal_ref = $is_dbm_deep && ($value->_root eq $root);
+ my $fileobj = $self->_fileobj;
- seek($fh, $location + $root->{file_offset}, SEEK_SET);
+ my $dbm_deep_obj = _get_dbm_object( $value );
+ if ( $dbm_deep_obj && $dbm_deep_obj->_fileobj ne $fileobj ) {
+ $self->_throw_error( "Cannot cross-reference. Use export() instead" );
+ }
##
# Write signature based on content type, set content length and write
# actual value.
##
- my $r = Scalar::Util::reftype($value) || '';
- if ( $is_internal_ref ) {
- $self->write_tag( $obj, undef, SIG_INTERNAL,pack($self->{long_pack}, $value->_base_offset) );
+ my $r = Scalar::Util::reftype( $value ) || '';
+ if ( $dbm_deep_obj ) {
+ $self->write_tag( $location, SIG_INTERNAL,pack($self->{long_pack}, $dbm_deep_obj->_base_offset) );
}
elsif ($r eq 'HASH') {
- if ( tied( %{$value} ) ) {
- $obj->_throw_error( "Cannot store something that is tied" );
+ if ( !$dbm_deep_obj && tied %{$value} ) {
+ $self->_throw_error( "Cannot store something that is tied" );
}
- $self->write_tag( $obj, undef, SIG_HASH, chr(0)x$self->{index_size} );
+ $self->write_tag( $location, SIG_HASH, chr(0)x$self->{index_size} );
}
elsif ($r eq 'ARRAY') {
- if ( tied( @{$value} ) ) {
- $obj->_throw_error( "Cannot store something that is tied" );
+ if ( !$dbm_deep_obj && tied @{$value} ) {
+ $self->_throw_error( "Cannot store something that is tied" );
}
- $self->write_tag( $obj, undef, SIG_ARRAY, chr(0)x$self->{index_size} );
+ $self->write_tag( $location, SIG_ARRAY, chr(0)x$self->{index_size} );
}
elsif (!defined($value)) {
- $self->write_tag( $obj, undef, SIG_NULL, '' );
+ $self->write_tag( $location, SIG_NULL, '' );
}
else {
- $self->write_tag( $obj, undef, SIG_DATA, $value );
+ $self->write_tag( $location, SIG_DATA, $value );
}
##
# Plain key is stored AFTER value, as keys are typically fetched less often.
##
- print( $fh pack($self->{data_pack}, length($key)) . $key );
+ $fileobj->print_at( undef, pack($self->{data_pack}, length($key)) . $key );
# Internal references don't care about autobless
- return 1 if $is_internal_ref;
+ return 1 if $dbm_deep_obj;
##
# If value is blessed, preserve class name
##
- if ( $root->{autobless} ) {
- my $value_class = Scalar::Util::blessed($value);
- if ( defined $value_class && !$is_dbm_deep ) {
- print( $fh chr(1) );
- print( $fh pack($self->{data_pack}, length($value_class)) . $value_class );
+ if ( $fileobj->{autobless} ) {
+ if ( defined( my $c = Scalar::Util::blessed($value) ) ) {
+ $fileobj->print_at( undef, chr(1), pack($self->{data_pack}, length($c)) . $c );
}
else {
- print( $fh chr(0) );
+ $fileobj->print_at( undef, chr(0) );
}
}
##
- # If content is a hash or array, create new child DBM::Deep object and
- # pass each key or element to it.
+ # Tie the passed in reference so that changes to it are reflected in the
+ # datafile. The use of $location as the base_offset will act as the
+ # the linkage between parent and child.
+ #
+ # The overall assignment is a hack around the fact that just tying doesn't
+ # store the values. This may not be the wrong thing to do.
##
- if ( !$is_internal_ref ) {
- if ($r eq 'HASH') {
- my $branch = DBM::Deep->new(
- type => DBM::Deep->TYPE_HASH,
- base_offset => $location,
- root => $root,
- );
- foreach my $key (keys %{$value}) {
- $branch->STORE( $key, $value->{$key} );
- }
- }
- elsif ($r eq 'ARRAY') {
- my $branch = DBM::Deep->new(
- type => DBM::Deep->TYPE_ARRAY,
- base_offset => $location,
- root => $root,
- );
- my $index = 0;
- foreach my $element (@{$value}) {
- $branch->STORE( $index, $element );
- $index++;
- }
- }
+ if ($r eq 'HASH') {
+ my %x = %$value;
+ tie %$value, 'DBM::Deep', {
+ base_offset => $location,
+ fileobj => $fileobj,
+ parent => $self->{obj},
+ parent_key => $orig_key,
+ };
+ %$value = %x;
+ }
+ elsif ($r eq 'ARRAY') {
+ my @x = @$value;
+ tie @$value, 'DBM::Deep', {
+ base_offset => $location,
+ fileobj => $fileobj,
+ parent => $self->{obj},
+ parent_key => $orig_key,
+ };
+ @$value = @x;
}
return 1;
sub split_index {
my $self = shift;
- my ($obj, $md5, $tag) = @_;
+ my ($md5, $tag) = @_;
- my $fh = $obj->_fh;
- my $root = $obj->_root;
+ my $fileobj = $self->_fileobj;
- my $loc = $self->_request_space(
- $obj, $self->tag_size( $self->{index_size} ),
+ my $loc = $fileobj->request_space(
+ $self->tag_size( $self->{index_size} ),
);
- seek($fh, $tag->{ref_loc} + $root->{file_offset}, SEEK_SET);
- print( $fh pack($self->{long_pack}, $loc) );
+ $fileobj->print_at( $tag->{ref_loc}, pack($self->{long_pack}, $loc) );
my $index_tag = $self->write_tag(
- $obj, $loc, SIG_INDEX,
+ $loc, SIG_INDEX,
chr(0)x$self->{index_size},
);
- my $newtag_loc = $self->_request_space(
- $obj, $self->tag_size( $self->{bucket_list_size} ),
+ my $newtag_loc = $fileobj->request_space(
+ $self->tag_size( $self->{bucket_list_size} ),
);
my $keys = $tag->{content}
. $md5 . pack($self->{long_pack}, $newtag_loc)
- . pack($self->{long_pack}, 0);
+ . pack($self->{long_pack}, 0) # size
+ . pack($self->{long_pack}, 0); # transaction ID
my @newloc = ();
BUCKET:
+ # The <= here is deliberate - we have max_buckets+1 keys to iterate
+ # through, unlike every other loop that uses max_buckets as a stop.
for (my $i = 0; $i <= $self->{max_buckets}; $i++) {
my ($key, $old_subloc, $size) = $self->_get_key_subloc( $keys, $i );
my $num = ord(substr($key, $tag->{ch} + 1, 1));
if ($newloc[$num]) {
- seek($fh, $newloc[$num] + $root->{file_offset}, SEEK_SET);
- my $subkeys;
- read( $fh, $subkeys, $self->{bucket_list_size});
+ my $subkeys = $fileobj->read_at( $newloc[$num], $self->{bucket_list_size} );
# This is looking for the first empty spot
my ($subloc, $offset, $size) = $self->_find_in_buckets(
{ content => $subkeys }, '',
);
- seek($fh, $newloc[$num] + $offset + $root->{file_offset}, SEEK_SET);
- print( $fh $key . pack($self->{long_pack}, $old_subloc) );
+ $fileobj->print_at(
+ $newloc[$num] + $offset,
+ $key, pack($self->{long_pack}, $old_subloc),
+ );
next;
}
- seek($fh, $index_tag->{offset} + ($num * $self->{long_size}) + $root->{file_offset}, SEEK_SET);
-
- my $loc = $self->_request_space(
- $obj, $self->tag_size( $self->{bucket_list_size} ),
+ my $loc = $fileobj->request_space(
+ $self->tag_size( $self->{bucket_list_size} ),
);
- print( $fh pack($self->{long_pack}, $loc) );
+ $fileobj->print_at(
+ $index_tag->{offset} + ($num * $self->{long_size}),
+ pack($self->{long_pack}, $loc),
+ );
my $blist_tag = $self->write_tag(
- $obj, $loc, SIG_BLIST,
+ $loc, SIG_BLIST,
chr(0)x$self->{bucket_list_size},
);
- seek($fh, $blist_tag->{offset} + $root->{file_offset}, SEEK_SET);
- print( $fh $key . pack($self->{long_pack}, $old_subloc) );
+ $fileobj->print_at( $blist_tag->{offset}, $key . pack($self->{long_pack}, $old_subloc) );
$newloc[$num] = $blist_tag->{offset};
}
$self->_release_space(
- $obj, $self->tag_size( $self->{bucket_list_size} ),
+ $self->tag_size( $self->{bucket_list_size} ),
$tag->{offset} - SIG_SIZE - $self->{data_size},
);
sub read_from_loc {
my $self = shift;
- my ($obj, $subloc) = @_;
+ my ($subloc, $orig_key) = @_;
- my $fh = $obj->_fh;
+ my $fileobj = $self->_fileobj;
- ##
- # Found match -- seek to offset and read signature
- ##
- my $signature;
- seek($fh, $subloc + $obj->_root->{file_offset}, SEEK_SET);
- read( $fh, $signature, SIG_SIZE);
+ my $signature = $fileobj->read_at( $subloc, SIG_SIZE );
##
# If value is a hash or array, return new DBM::Deep object with correct offset
##
if (($signature eq SIG_HASH) || ($signature eq SIG_ARRAY)) {
- my $obj = DBM::Deep->new(
- type => $signature,
+ my $new_obj = DBM::Deep->new({
+ type => $signature,
base_offset => $subloc,
- root => $obj->_root,
- );
+ fileobj => $self->_fileobj,
+ parent => $self->{obj},
+ parent_key => $orig_key,
+ });
- if ($obj->_root->{autobless}) {
+ if ($new_obj->_fileobj->{autobless}) {
##
# Skip over value and plain key to see if object needs
# to be re-blessed
##
- seek($fh, $self->{data_size} + $self->{index_size}, SEEK_CUR);
+ $fileobj->increment_pointer( $self->{data_size} + $self->{index_size} );
- my $size;
- read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size);
- if ($size) { seek($fh, $size, SEEK_CUR); }
+ my $size = $fileobj->read_at( undef, $self->{data_size} );
+ $size = unpack($self->{data_pack}, $size);
+ if ($size) { $fileobj->increment_pointer( $size ); }
- my $bless_bit;
- read( $fh, $bless_bit, 1);
+ my $bless_bit = $fileobj->read_at( undef, 1 );
if (ord($bless_bit)) {
##
# Yes, object needs to be re-blessed
##
+ my $size = $fileobj->read_at( undef, $self->{data_size} );
+ $size = unpack($self->{data_pack}, $size);
+
my $class_name;
- read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size);
- if ($size) { read( $fh, $class_name, $size); }
- if ($class_name) { $obj = bless( $obj, $class_name ); }
+ if ($size) { $class_name = $fileobj->read_at( undef, $size ); }
+ if (defined $class_name) { $new_obj = bless( $new_obj, $class_name ); }
}
}
- return $obj;
+ return $new_obj;
}
elsif ( $signature eq SIG_INTERNAL ) {
- my $size;
- read( $fh, $size, $self->{data_size});
+ my $size = $fileobj->read_at( undef, $self->{data_size} );
$size = unpack($self->{data_pack}, $size);
if ( $size ) {
- my $new_loc;
- read( $fh, $new_loc, $size );
- $new_loc = unpack( $self->{long_pack}, $new_loc );
-
- return $self->read_from_loc( $obj, $new_loc );
+ my $new_loc = $fileobj->read_at( undef, $size );
+ $new_loc = unpack( $self->{long_pack}, $new_loc );
+ return $self->read_from_loc( $new_loc, $orig_key );
}
else {
return;
##
# Otherwise return actual value
##
- elsif ($signature eq SIG_DATA) {
- my $size;
- read( $fh, $size, $self->{data_size});
+ elsif ( $signature eq SIG_DATA ) {
+ my $size = $fileobj->read_at( undef, $self->{data_size} );
$size = unpack($self->{data_pack}, $size);
my $value = '';
- if ($size) { read( $fh, $value, $size); }
+ if ($size) { $value = $fileobj->read_at( undef, $size ); }
return $value;
}
# Fetch single value given tag and MD5 digested key.
##
my $self = shift;
- my ($obj, $tag, $md5) = @_;
+ my ($tag, $md5, $orig_key) = @_;
- my ($subloc, $offset, $size) = $self->_find_in_buckets( $tag, $md5 );
- if ( $subloc ) {
- return $self->read_from_loc( $obj, $subloc );
+ #ACID - This is a read. Can find exact or HEAD
+ my ($subloc, $offset, $size, $is_deleted) = $self->_find_in_buckets( $tag, $md5 );
+
+ if ( !$subloc ) {
+ #XXX Need to use real key
+# $self->add_bucket( $tag, $md5, $orig_key, undef, undef, $orig_key );
+# return;
}
+ elsif ( !$is_deleted ) {
+ return $self->read_from_loc( $subloc, $orig_key );
+ }
+
return;
}
# Delete single key/value pair given tag and MD5 digested key.
##
my $self = shift;
- my ($obj, $tag, $md5) = @_;
+ my ($tag, $md5, $orig_key) = @_;
- my ($subloc, $offset, $size) = $self->_find_in_buckets( $tag, $md5 );
-#XXX This needs _release_space()
- if ( $subloc ) {
- my $fh = $obj->_fh;
- seek($fh, $tag->{offset} + $offset + $obj->_root->{file_offset}, SEEK_SET);
- print( $fh substr($tag->{content}, $offset + $self->{bucket_size} ) );
- print( $fh chr(0) x $self->{bucket_size} );
+ #ACID - Although this is a mutation, we must find any transaction.
+ # This is because we need to mark something as deleted that is in the HEAD.
+ my ($subloc, $offset, $size,$is_deleted) = $self->_find_in_buckets( $tag, $md5 );
+
+ return if !$subloc;
+
+ my $fileobj = $self->_fileobj;
- return 1;
+ my @transactions;
+ if ( $fileobj->transaction_id == 0 ) {
+ @transactions = $fileobj->current_transactions;
}
- return;
+
+ if ( $fileobj->transaction_id == 0 ) {
+ my $value = $self->read_from_loc( $subloc, $orig_key );
+
+ for (@transactions) {
+ $fileobj->{transaction_id} = $_;
+ #XXX Need to use real key
+ $self->add_bucket( $tag, $md5, $orig_key, $value, undef, $orig_key );
+ $fileobj->{transaction_id} = 0;
+ }
+ $tag = $self->load_tag( $tag->{offset} - SIG_SIZE - $self->{data_size} );
+
+ #XXX This needs _release_space() for the value and anything below
+ $fileobj->print_at(
+ $tag->{offset} + $offset,
+ substr( $tag->{content}, $offset + $self->{bucket_size} ),
+ chr(0) x $self->{bucket_size},
+ );
+ }
+ else {
+ $self->add_bucket( $tag, $md5, '', '', 1, $orig_key );
+ }
+
+ return 1;
}
sub bucket_exists {
# Check existence of single key given tag and MD5 digested key.
##
my $self = shift;
- my ($obj, $tag, $md5) = @_;
+ my ($tag, $md5) = @_;
- my ($subloc, $offset, $size) = $self->_find_in_buckets( $tag, $md5 );
- return $subloc && 1;
+ #ACID - This is a read. Can find exact or HEAD
+ my ($subloc, $offset, $size, $is_deleted) = $self->_find_in_buckets( $tag, $md5 );
+ return ($subloc && !$is_deleted) && 1;
}
sub find_bucket_list {
# Locate offset for bucket list, given digested key
##
my $self = shift;
- my ($obj, $md5, $args) = @_;
+ my ($offset, $md5, $args) = @_;
$args = {} unless $args;
+ local($/,$\);
+
##
# Locate offset for bucket list using digest index system
##
- my $tag = $self->load_tag($obj, $obj->_base_offset)
- or $obj->_throw_error( "INTERNAL ERROR - Cannot find tag" );
+ my $tag = $self->load_tag( $offset )
+ or $self->_throw_error( "INTERNAL ERROR - Cannot find tag" );
my $ch = 0;
while ($tag->{signature} ne SIG_BLIST) {
my $num = ord substr($md5, $ch, 1);
my $ref_loc = $tag->{offset} + ($num * $self->{long_size});
- $tag = $self->index_lookup( $obj, $tag, $num );
+ $tag = $self->index_lookup( $tag, $num );
if (!$tag) {
return if !$args->{create};
- my $loc = $self->_request_space(
- $obj, $self->tag_size( $self->{bucket_list_size} ),
+ my $loc = $self->_fileobj->request_space(
+ $self->tag_size( $self->{bucket_list_size} ),
);
- my $fh = $obj->_fh;
- seek($fh, $ref_loc + $obj->_root->{file_offset}, SEEK_SET);
- print( $fh pack($self->{long_pack}, $loc) );
+ $self->_fileobj->print_at( $ref_loc, pack($self->{long_pack}, $loc) );
$tag = $self->write_tag(
- $obj, $loc, SIG_BLIST,
+ $loc, SIG_BLIST,
chr(0)x$self->{bucket_list_size},
);
# Given index tag, lookup single entry in index and return .
##
my $self = shift;
- my ($obj, $tag, $index) = @_;
+ my ($tag, $index) = @_;
my $location = unpack(
$self->{long_pack},
if (!$location) { return; }
- return $self->load_tag( $obj, $location );
+ return $self->load_tag( $location );
}
sub traverse_index {
my $self = shift;
my ($obj, $offset, $ch, $force_return_next) = @_;
- my $tag = $self->load_tag($obj, $offset );
-
- my $fh = $obj->_fh;
+ my $tag = $self->load_tag( $offset );
if ($tag->{signature} ne SIG_BLIST) {
my $content = $tag->{content};
} # index loop
$obj->{return_next} = 1;
- } # tag is an index
-
+ }
+ # This is the bucket list
else {
my $keys = $tag->{content};
if ($force_return_next) { $obj->{return_next} = 1; }
##
# Iterate through buckets, looking for a key match
##
+ my $transaction_id = $self->_fileobj->transaction_id;
for (my $i = 0; $i < $self->{max_buckets}; $i++) {
- my ($key, $subloc) = $self->_get_key_subloc( $keys, $i );
+ my ($key, $subloc, $size, $trans_id, $is_deleted) = $self->_get_key_subloc( $keys, $i );
+
+ next if $is_deleted;
+#XXX Need to find all the copies of this key to find out if $transaction_id has it
+#XXX marked as deleted, in use, or what.
+ next if $trans_id && $trans_id != $transaction_id;
# End of bucket list -- return to outer loop
if (!$subloc) {
}
# Seek to bucket location and skip over signature
elsif ($obj->{return_next}) {
- seek($fh, $subloc + $obj->_root->{file_offset}, SEEK_SET);
+ my $fileobj = $self->_fileobj;
# Skip over value to get to plain key
- my $sig;
- read( $fh, $sig, SIG_SIZE );
+ my $sig = $fileobj->read_at( $subloc, SIG_SIZE );
- my $size;
- read( $fh, $size, $self->{data_size});
+ my $size = $fileobj->read_at( undef, $self->{data_size} );
$size = unpack($self->{data_pack}, $size);
- if ($size) { seek($fh, $size, SEEK_CUR); }
+ if ($size) { $fileobj->increment_pointer( $size ); }
# Read in plain key and return as scalar
- my $plain_key;
- read( $fh, $size, $self->{data_size});
+ $size = $fileobj->read_at( undef, $self->{data_size} );
$size = unpack($self->{data_pack}, $size);
- if ($size) { read( $fh, $plain_key, $size); }
+ my $plain_key;
+ if ($size) { $plain_key = $fileobj->read_at( undef, $size); }
return $plain_key;
}
}
$obj->{return_next} = 1;
- } # tag is a bucket list
+ }
return;
}
my $self = shift;
my ($keys, $idx) = @_;
- my ($key, $subloc, $size) = unpack(
- "a$self->{hash_size} $self->{long_pack} $self->{long_pack}",
+ my ($key, $subloc, $size, $transaction_id, $is_deleted) = unpack(
+ # This is 'a', not 'A'. Please read the pack() documentation for the
+ # difference between the two and why it's important.
+ "a$self->{hash_size} $self->{long_pack}2 n2",
substr(
$keys,
($idx * $self->{bucket_size}),
),
);
- return ($key, $subloc, $size);
+ return ($key, $subloc, $size, $transaction_id, $is_deleted);
}
sub _find_in_buckets {
my $self = shift;
- my ($tag, $md5) = @_;
+ my ($tag, $md5, $exact) = @_;
+ $exact ||= 0;
+
+ my $trans_id = $self->_fileobj->transaction_id;
+
+ my @zero;
BUCKET:
for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
- my ($key, $subloc, $size) = $self->_get_key_subloc(
+ my ($key, $subloc, $size, $transaction_id, $is_deleted) = $self->_get_key_subloc(
$tag->{content}, $i,
);
- return ($subloc, $i * $self->{bucket_size}, $size) unless $subloc;
+ my @rv = ($subloc, $i * $self->{bucket_size}, $size, $is_deleted);
- next BUCKET if $key ne $md5;
+ unless ( $subloc ) {
+ if ( !$exact && @zero && $trans_id ) {
+ @rv = ($zero[2], $zero[0] * $self->{bucket_size},$zero[3],$is_deleted);
+ }
+ return @rv;
+ }
- return ($subloc, $i * $self->{bucket_size}, $size);
- }
+ next BUCKET if $key ne $md5;
- return;
-}
+ # Save off the HEAD in case we need it.
+ @zero = ($i,$key,$subloc,$size,$transaction_id,$is_deleted) if $transaction_id == 0;
-#sub _print_at {
-# my $self = shift;
-# my ($obj, $spot, $data) = @_;
-#
-# my $fh = $obj->_fh;
-# seek( $fh, $spot, SEEK_SET );
-# print( $fh $data );
-#
-# return;
-#}
-
-sub _request_space {
- my $self = shift;
- my ($obj, $size) = @_;
+ next BUCKET if $transaction_id != $trans_id;
- my $loc = $obj->_root->{end};
- $obj->_root->{end} += $size;
+ return @rv;
+ }
- return $loc;
+ return;
}
sub _release_space {
my $self = shift;
- my ($obj, $size, $loc) = @_;
+ my ($size, $loc) = @_;
my $next_loc = 0;
- my $fh = $obj->_fh;
- seek( $fh, $loc + $obj->_root->{file_offset}, SEEK_SET );
- print( $fh SIG_FREE
- . pack($self->{long_pack}, $size )
- . pack($self->{long_pack}, $next_loc )
+ $self->_fileobj->print_at( $loc,
+ SIG_FREE,
+ pack($self->{long_pack}, $size ),
+ pack($self->{long_pack}, $next_loc ),
);
return;
}
+sub _throw_error {
+ die "DBM::Deep: $_[1]\n";
+}
+
1;
__END__
-
-# This will be added in later, after more refactoring is done. This is an early
-# attempt at refactoring on the physical level instead of the virtual level.
-sub _read_at {
- my $self = shift;
- my ($obj, $spot, $amount, $unpack) = @_;
-
- my $fh = $obj->_fh;
- seek( $fh, $spot + $obj->_root->{file_offset}, SEEK_SET );
-
- my $buffer;
- my $bytes_read = read( $fh, $buffer, $amount );
-
- if ( $unpack ) {
- $buffer = unpack( $unpack, $buffer );
- }
-
- if ( wantarray ) {
- return ($buffer, $bytes_read);
- }
- else {
- return $buffer;
- }
-}
projects / dbsrgits/DBM-Deep.git / blobdiff