use Fcntl qw( :DEFAULT :flock :seek );
sub open {
- ##
- # Open a fh to the database, create if nonexistent.
- # Make sure file signature matches DBM::Deep spec.
- ##
+ ##
+ # Open a fh to the database, create if nonexistent.
+ # Make sure file signature matches DBM::Deep spec.
+ ##
my $self = shift;
my $obj = shift;
- if (defined($obj->_fh)) { $self->close( $obj ); }
-
+ if (defined($obj->_fh)) { $self->close( $obj ); }
+
eval {
local $SIG{'__DIE__'};
# Theoretically, adding O_BINARY should remove the need for the binmode
or $fh = undef;
$obj->_root->{fh} = $fh;
}; if ($@ ) { $obj->_throw_error( "Received error: $@\n" ); }
- if (! defined($obj->_fh)) {
- return $obj->_throw_error("Cannot sysopen file: " . $obj->_root->{file} . ": $!");
- }
+ if (! defined($obj->_fh)) {
+ return $obj->_throw_error("Cannot sysopen file: " . $obj->_root->{file} . ": $!");
+ }
my $fh = $obj->_fh;
$|=1;
select $old;
}
-
+
seek($fh, 0 + $obj->_root->{file_offset}, SEEK_SET);
my $signature;
my $bytes_read = read( $fh, $signature, length(DBM::Deep->SIG_FILE));
-
+
##
# File is empty -- write signature and master index
##
if (!$bytes_read) {
seek($fh, 0 + $obj->_root->{file_offset}, SEEK_SET);
print( $fh DBM::Deep->SIG_FILE);
- $obj->_create_tag($obj->_base_offset, $obj->_type, chr(0) x $DBM::Deep::INDEX_SIZE);
+ $self->create_tag($obj, $obj->_base_offset, $obj->_type, chr(0) x $DBM::Deep::INDEX_SIZE);
my $plain_key = "[base]";
print( $fh pack($DBM::Deep::DATA_LENGTH_PACK, length($plain_key)) . $plain_key );
return 1;
}
-
+
##
# Check signature was valid
##
return $obj->_throw_error("Signature not found -- file is not a Deep DB");
}
- my @stats = stat($fh);
- $obj->_root->{inode} = $stats[1];
+ my @stats = stat($fh);
+ $obj->_root->{inode} = $stats[1];
$obj->_root->{end} = $stats[7];
-
+
##
# Get our type from master index signature
##
- my $tag = $obj->_load_tag($obj->_base_offset);
+ my $tag = $self->load_tag($obj, $obj->_base_offset);
#XXX We probably also want to store the hash algorithm name and not assume anything
#XXX The cool thing would be to allow a different hashing algorithm at every level
if (!$tag) {
- return $obj->_throw_error("Corrupted file, no master index record");
+ return $obj->_throw_error("Corrupted file, no master index record");
}
if ($obj->{type} ne $tag->{signature}) {
- return $obj->_throw_error("File type mismatch");
+ return $obj->_throw_error("File type mismatch");
}
-
+
return 1;
}
return 1;
}
+sub create_tag {
+ ##
+ # Given offset, signature and content, create tag and write to disk
+ ##
+ my $self = shift;
+ my ($obj, $offset, $sig, $content) = @_;
+ my $size = length($content);
+
+ my $fh = $obj->_fh;
+
+ seek($fh, $offset + $obj->_root->{file_offset}, SEEK_SET);
+ print( $fh $sig . pack($DBM::Deep::DATA_LENGTH_PACK, $size) . $content );
+
+ if ($offset == $obj->_root->{end}) {
+ $obj->_root->{end} += DBM::Deep->SIG_SIZE + $DBM::Deep::DATA_LENGTH_SIZE + $size;
+ }
+
+ return {
+ signature => $sig,
+ size => $size,
+ offset => $offset + DBM::Deep->SIG_SIZE + $DBM::Deep::DATA_LENGTH_SIZE,
+ content => $content
+ };
+}
+
+sub load_tag {
+ ##
+ # Given offset, load single tag and return signature, size and data
+ ##
+ my $self = shift;
+ my ($obj, $offset) = @_;
+
+ my $fh = $obj->_fh;
+
+ seek($fh, $offset + $obj->_root->{file_offset}, SEEK_SET);
+ if (eof $fh) { return undef; }
+
+ my $b;
+ read( $fh, $b, DBM::Deep->SIG_SIZE + $DBM::Deep::DATA_LENGTH_SIZE );
+ my ($sig, $size) = unpack( "A $DBM::Deep::DATA_LENGTH_PACK", $b );
+
+ my $buffer;
+ read( $fh, $buffer, $size);
+
+ return {
+ signature => $sig,
+ size => $size,
+ offset => $offset + DBM::Deep->SIG_SIZE + $DBM::Deep::DATA_LENGTH_SIZE,
+ content => $buffer
+ };
+}
+
+sub index_lookup {
+ ##
+ # Given index tag, lookup single entry in index and return .
+ ##
+ my $self = shift;
+ my ($obj, $tag, $index) = @_;
+
+ my $location = unpack($DBM::Deep::LONG_PACK, substr($tag->{content}, $index * $DBM::Deep::LONG_SIZE, $DBM::Deep::LONG_SIZE) );
+ if (!$location) { return; }
+
+ return $self->load_tag( $obj, $location );
+}
+
+sub add_bucket {
+ ##
+ # Adds one key/value pair to bucket list, given offset, MD5 digest of key,
+ # plain (undigested) key and value.
+ ##
+ my $self = shift;
+ my ($obj, $tag, $md5, $plain_key, $value) = @_;
+ my $keys = $tag->{content};
+ my $location = 0;
+ my $result = 2;
+
+ my $root = $obj->_root;
+
+ my $is_dbm_deep = eval { local $SIG{'__DIE__'}; $value->isa( 'DBM::Deep' ) };
+ my $internal_ref = $is_dbm_deep && ($value->_root eq $root);
+
+ my $fh = $obj->_fh;
+
+ ##
+ # Iterate through buckets, seeing if this is a new entry or a replace.
+ ##
+ for (my $i=0; $i<$DBM::Deep::MAX_BUCKETS; $i++) {
+ my $subloc = unpack($DBM::Deep::LONG_PACK, substr($keys, ($i * $DBM::Deep::BUCKET_SIZE) + $DBM::Deep::HASH_SIZE, $DBM::Deep::LONG_SIZE));
+ if (!$subloc) {
+ ##
+ # Found empty bucket (end of list). Populate and exit loop.
+ ##
+ $result = 2;
+
+ $location = $internal_ref
+ ? $value->_base_offset
+ : $root->{end};
+
+ seek($fh, $tag->{offset} + ($i * $DBM::Deep::BUCKET_SIZE) + $root->{file_offset}, SEEK_SET);
+ print( $fh $md5 . pack($DBM::Deep::LONG_PACK, $location) );
+ last;
+ }
+
+ my $key = substr($keys, $i * $DBM::Deep::BUCKET_SIZE, $DBM::Deep::HASH_SIZE);
+ if ($md5 eq $key) {
+ ##
+ # Found existing bucket with same key. Replace with new value.
+ ##
+ $result = 1;
+
+ if ($internal_ref) {
+ $location = $value->_base_offset;
+ seek($fh, $tag->{offset} + ($i * $DBM::Deep::BUCKET_SIZE) + $root->{file_offset}, SEEK_SET);
+ print( $fh $md5 . pack($DBM::Deep::LONG_PACK, $location) );
+ return $result;
+ }
+
+ seek($fh, $subloc + DBM::Deep->SIG_SIZE + $root->{file_offset}, SEEK_SET);
+ my $size;
+ read( $fh, $size, $DBM::Deep::DATA_LENGTH_SIZE); $size = unpack($DBM::Deep::DATA_LENGTH_PACK, $size);
+
+ ##
+ # If value is a hash, array, or raw value with equal or less size, we can
+ # reuse the same content area of the database. Otherwise, we have to create
+ # a new content area at the EOF.
+ ##
+ my $actual_length;
+ my $r = Scalar::Util::reftype( $value ) || '';
+ if ( $r eq 'HASH' || $r eq 'ARRAY' ) {
+ $actual_length = $DBM::Deep::INDEX_SIZE;
+
+ # if autobless is enabled, must also take into consideration
+ # the class name, as it is stored along with key/value.
+ if ( $root->{autobless} ) {
+ my $value_class = Scalar::Util::blessed($value);
+ if ( defined $value_class && !$value->isa('DBM::Deep') ) {
+ $actual_length += length($value_class);
+ }
+ }
+ }
+ else { $actual_length = length($value); }
+
+ if ($actual_length <= $size) {
+ $location = $subloc;
+ }
+ else {
+ $location = $root->{end};
+ seek($fh, $tag->{offset} + ($i * $DBM::Deep::BUCKET_SIZE) + $DBM::Deep::HASH_SIZE + $root->{file_offset}, SEEK_SET);
+ print( $fh pack($DBM::Deep::LONG_PACK, $location) );
+ }
+
+ last;
+ }
+ }
+
+ ##
+ # If this is an internal reference, return now.
+ # No need to write value or plain key
+ ##
+ if ($internal_ref) {
+ return $result;
+ }
+
+ ##
+ # If bucket didn't fit into list, split into a new index level
+ ##
+ if (!$location) {
+ seek($fh, $tag->{ref_loc} + $root->{file_offset}, SEEK_SET);
+ print( $fh pack($DBM::Deep::LONG_PACK, $root->{end}) );
+
+ my $index_tag = $self->create_tag($obj, $root->{end}, DBM::Deep->SIG_INDEX, chr(0) x $DBM::Deep::INDEX_SIZE);
+ my @offsets = ();
+
+ $keys .= $md5 . pack($DBM::Deep::LONG_PACK, 0);
+
+ for (my $i=0; $i<=$DBM::Deep::MAX_BUCKETS; $i++) {
+ my $key = substr($keys, $i * $DBM::Deep::BUCKET_SIZE, $DBM::Deep::HASH_SIZE);
+ if ($key) {
+ my $old_subloc = unpack($DBM::Deep::LONG_PACK, substr($keys, ($i * $DBM::Deep::BUCKET_SIZE) +
+ $DBM::Deep::HASH_SIZE, $DBM::Deep::LONG_SIZE));
+ my $num = ord(substr($key, $tag->{ch} + 1, 1));
+
+ if ($offsets[$num]) {
+ my $offset = $offsets[$num] + DBM::Deep->SIG_SIZE + $DBM::Deep::DATA_LENGTH_SIZE;
+ seek($fh, $offset + $root->{file_offset}, SEEK_SET);
+ my $subkeys;
+ read( $fh, $subkeys, $DBM::Deep::BUCKET_LIST_SIZE);
+
+ for (my $k=0; $k<$DBM::Deep::MAX_BUCKETS; $k++) {
+ my $subloc = unpack($DBM::Deep::LONG_PACK, substr($subkeys, ($k * $DBM::Deep::BUCKET_SIZE) +
+ $DBM::Deep::HASH_SIZE, $DBM::Deep::LONG_SIZE));
+ if (!$subloc) {
+ seek($fh, $offset + ($k * $DBM::Deep::BUCKET_SIZE) + $root->{file_offset}, SEEK_SET);
+ print( $fh $key . pack($DBM::Deep::LONG_PACK, $old_subloc || $root->{end}) );
+ last;
+ }
+ } # k loop
+ }
+ else {
+ $offsets[$num] = $root->{end};
+ seek($fh, $index_tag->{offset} + ($num * $DBM::Deep::LONG_SIZE) + $root->{file_offset}, SEEK_SET);
+ print( $fh pack($DBM::Deep::LONG_PACK, $root->{end}) );
+
+ my $blist_tag = $self->create_tag($obj, $root->{end}, DBM::Deep->SIG_BLIST, chr(0) x $DBM::Deep::BUCKET_LIST_SIZE);
+
+ seek($fh, $blist_tag->{offset} + $root->{file_offset}, SEEK_SET);
+ print( $fh $key . pack($DBM::Deep::LONG_PACK, $old_subloc || $root->{end}) );
+ }
+ } # key is real
+ } # i loop
+
+ $location ||= $root->{end};
+ } # re-index bucket list
+
+ ##
+ # Seek to content area and store signature, value and plaintext key
+ ##
+ if ($location) {
+ my $content_length;
+ seek($fh, $location + $root->{file_offset}, SEEK_SET);
+
+ ##
+ # Write signature based on content type, set content length and write actual value.
+ ##
+ my $r = Scalar::Util::reftype($value) || '';
+ if ($r eq 'HASH') {
+ print( $fh DBM::Deep->TYPE_HASH );
+ print( $fh pack($DBM::Deep::DATA_LENGTH_PACK, $DBM::Deep::INDEX_SIZE) . chr(0) x $DBM::Deep::INDEX_SIZE );
+ $content_length = $DBM::Deep::INDEX_SIZE;
+ }
+ elsif ($r eq 'ARRAY') {
+ print( $fh DBM::Deep->TYPE_ARRAY );
+ print( $fh pack($DBM::Deep::DATA_LENGTH_PACK, $DBM::Deep::INDEX_SIZE) . chr(0) x $DBM::Deep::INDEX_SIZE );
+ $content_length = $DBM::Deep::INDEX_SIZE;
+ }
+ elsif (!defined($value)) {
+ print( $fh DBM::Deep->SIG_NULL );
+ print( $fh pack($DBM::Deep::DATA_LENGTH_PACK, 0) );
+ $content_length = 0;
+ }
+ else {
+ print( $fh DBM::Deep->SIG_DATA );
+ print( $fh pack($DBM::Deep::DATA_LENGTH_PACK, length($value)) . $value );
+ $content_length = length($value);
+ }
+
+ ##
+ # Plain key is stored AFTER value, as keys are typically fetched less often.
+ ##
+ print( $fh pack($DBM::Deep::DATA_LENGTH_PACK, length($plain_key)) . $plain_key );
+
+ ##
+ # If value is blessed, preserve class name
+ ##
+ if ( $root->{autobless} ) {
+ my $value_class = Scalar::Util::blessed($value);
+ if ( defined $value_class && $value_class ne 'DBM::Deep' ) {
+ ##
+ # Blessed ref -- will restore later
+ ##
+ print( $fh chr(1) );
+ print( $fh pack($DBM::Deep::DATA_LENGTH_PACK, length($value_class)) . $value_class );
+ $content_length += 1;
+ $content_length += $DBM::Deep::DATA_LENGTH_SIZE + length($value_class);
+ }
+ else {
+ print( $fh chr(0) );
+ $content_length += 1;
+ }
+ }
+
+ ##
+ # If this is a new content area, advance EOF counter
+ ##
+ if ($location == $root->{end}) {
+ $root->{end} += DBM::Deep->SIG_SIZE;
+ $root->{end} += $DBM::Deep::DATA_LENGTH_SIZE + $content_length;
+ $root->{end} += $DBM::Deep::DATA_LENGTH_SIZE + length($plain_key);
+ }
+
+ ##
+ # If content is a hash or array, create new child DBM::Deep object and
+ # pass each key or element to it.
+ ##
+ 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++;
+ }
+ }
+
+ return $result;
+ }
+
+ return $obj->_throw_error("Fatal error: indexing failed -- possibly due to corruption in file");
+}
+
1;
__END__
projects / dbsrgits/DBM-Deep.git / blobdiff