use Fcntl qw( :DEFAULT :flock :seek );
-##
-# 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)
-##
-##
-# 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 :-)
-##
-our ($LONG_SIZE, $LONG_PACK, $DATA_LENGTH_SIZE, $DATA_LENGTH_PACK);
-##
-# Maximum number of buckets per list before another level of indexing is 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.
-##
-our $MAX_BUCKETS = 16;
-our ($HASH_SIZE);
-our ($BUCKET_SIZE, $BUCKET_LIST_SIZE);
-set_digest();
-
sub precalc_sizes {
- ##
- # Precalculate index, bucket and bucket list sizes
- ##
+ ##
+ # Precalculate index, bucket and bucket list sizes
+ ##
+ my $self = shift;
- #XXX I don't like this ...
- set_pack() unless defined $LONG_SIZE;
+ $self->{index_size} = (2**8) * $self->{long_size};
+ $self->{bucket_size} = $self->{hash_size} + $self->{long_size};
+ $self->{bucket_list_size} = $self->{max_buckets} * $self->{bucket_size};
- $BUCKET_SIZE = $HASH_SIZE + $LONG_SIZE;
- $BUCKET_LIST_SIZE = $MAX_BUCKETS * $BUCKET_SIZE;
+ return 1;
}
sub set_pack {
- ##
- # Set pack/unpack modes (see file header for more)
- ##
+ ##
+ # Set pack/unpack modes (see file header for more)
+ ##
+ my $self = shift;
my ($long_s, $long_p, $data_s, $data_p) = @_;
- $LONG_SIZE = $long_s ? $long_s : 4;
- $LONG_PACK = $long_p ? $long_p : 'N';
+ ##
+ # 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';
- $DATA_LENGTH_SIZE = $data_s ? $data_s : 4;
- $DATA_LENGTH_PACK = $data_p ? $data_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';
- precalc_sizes();
+ return $self->precalc_sizes();
}
sub set_digest {
+ ##
+ # Set key digest function (default is MD5)
+ ##
my $self = shift;
- ##
- # Set key digest function (default is MD5)
- ##
my ($digest_func, $hash_size) = @_;
- $self->{digest} = $digest_func ? $digest_func : \&Digest::MD5::md5;
-
- $HASH_SIZE = $hash_size ? $hash_size : 16;
+ $self->{digest} = $digest_func ? $digest_func : \&Digest::MD5::md5;
+ $self->{hash_size} = $hash_size ? $hash_size : 16;
- precalc_sizes();
+ return $self->precalc_sizes();
}
sub new {
long_pack => 'N',
data_size => 4,
data_pack => 'N',
+
digest => \&Digest::MD5::md5,
hash_size => 16,
+
+ ##
+ # Maximum number of buckets per list before another level of indexing is 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,
}, $class;
- $self->{index_size} = (2**8) * $self->{long_size};
- $self->{bucket_size} = $self->{hash_size} + $self->{long_size};
- $self->{bucket_list_size} = $self->{max_buckets} * $self->{bucket_size};
+ $self->precalc_sizes;
return $self;
}
my $self = shift;
my ($obj) = @_;
- if (defined($obj->_fh)) { $self->close( $obj ); }
+ if (defined($obj->_fh)) { $self->close_fh( $obj ); }
eval {
local $SIG{'__DIE__'};
if (!$bytes_read) {
seek($fh, 0 + $obj->_root->{file_offset}, SEEK_SET);
print( $fh DBM::Deep->SIG_FILE);
+
$self->create_tag($obj, $obj->_base_offset, $obj->_type, chr(0) x $self->{index_size});
my $plain_key = "[base]";
- print( $fh pack($DATA_LENGTH_PACK, length($plain_key)) . $plain_key );
+ print( $fh pack($self->{data_pack}, length($plain_key)) . $plain_key );
# Flush the filehandle
my $old_fh = select $fh;
# Check signature was valid
##
unless ($signature eq DBM::Deep->SIG_FILE) {
- $self->close( $obj );
+ $self->close_fh( $obj );
return $obj->_throw_error("Signature not found -- file is not a Deep DB");
}
# Get our type from master index signature
##
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 $obj->_throw_error("Corrupted file, no master index record");
}
+
if ($obj->{type} ne $tag->{signature}) {
return $obj->_throw_error("File type mismatch");
}
+#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
+
return 1;
}
-sub close {
+sub close_fh {
my $self = shift;
- my $obj = shift;
+ my ($obj) = @_;
if ( my $fh = $obj->_root->{fh} ) {
close $fh;
my $fh = $obj->_fh;
seek($fh, $offset + $obj->_root->{file_offset}, SEEK_SET);
- print( $fh $sig . pack($DATA_LENGTH_PACK, $size) . $content );
+ print( $fh $sig . pack($self->{data_pack}, $size) . $content );
if ($offset == $obj->_root->{end}) {
- $obj->_root->{end} += DBM::Deep->SIG_SIZE + $DATA_LENGTH_SIZE + $size;
+ $obj->_root->{end} += DBM::Deep->SIG_SIZE + $self->{data_size} + $size;
}
return {
signature => $sig,
size => $size,
- offset => $offset + DBM::Deep->SIG_SIZE + $DATA_LENGTH_SIZE,
+ offset => $offset + DBM::Deep->SIG_SIZE + $self->{data_size},
content => $content
};
}
if (eof $fh) { return undef; }
my $b;
- read( $fh, $b, DBM::Deep->SIG_SIZE + $DATA_LENGTH_SIZE );
- my ($sig, $size) = unpack( "A $DATA_LENGTH_PACK", $b );
+ read( $fh, $b, DBM::Deep->SIG_SIZE + $self->{data_size} );
+ my ($sig, $size) = unpack( "A $self->{data_pack}", $b );
my $buffer;
read( $fh, $buffer, $size);
return {
signature => $sig,
size => $size,
- offset => $offset + DBM::Deep->SIG_SIZE + $DATA_LENGTH_SIZE,
+ offset => $offset + DBM::Deep->SIG_SIZE + $self->{data_size},
content => $buffer
};
}
-sub index_lookup {
- ##
- # Given index tag, lookup single entry in index and return .
- ##
- my $self = shift;
- my ($obj, $tag, $index) = @_;
-
- my $location = unpack($LONG_PACK, substr($tag->{content}, $index * $LONG_SIZE, $LONG_SIZE) );
- if (!$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,
##
# Iterate through buckets, seeing if this is a new entry or a replace.
##
- for (my $i=0; $i<$MAX_BUCKETS; $i++) {
- my $subloc = unpack($LONG_PACK, substr($keys, ($i * $BUCKET_SIZE) + $HASH_SIZE, $LONG_SIZE));
+ for (my $i = 0; $i < $self->{max_buckets}; $i++) {
+ my $subloc = unpack($self->{long_pack}, substr($keys, ($i * $self->{bucket_size}) + $self->{hash_size}, $self->{long_size}));
if (!$subloc) {
##
# Found empty bucket (end of list). Populate and exit loop.
? $value->_base_offset
: $root->{end};
- seek($fh, $tag->{offset} + ($i * $BUCKET_SIZE) + $root->{file_offset}, SEEK_SET);
- print( $fh $md5 . pack($LONG_PACK, $location) );
+ seek($fh, $tag->{offset} + ($i * $self->{bucket_size}) + $root->{file_offset}, SEEK_SET);
+ print( $fh $md5 . pack($self->{long_pack}, $location) );
last;
}
- my $key = substr($keys, $i * $BUCKET_SIZE, $HASH_SIZE);
+ my $key = substr($keys, $i * $self->{bucket_size}, $self->{hash_size});
if ($md5 eq $key) {
##
# Found existing bucket with same key. Replace with new value.
if ($internal_ref) {
$location = $value->_base_offset;
- seek($fh, $tag->{offset} + ($i * $BUCKET_SIZE) + $root->{file_offset}, SEEK_SET);
- print( $fh $md5 . pack($LONG_PACK, $location) );
+ seek($fh, $tag->{offset} + ($i * $self->{bucket_size}) + $root->{file_offset}, SEEK_SET);
+ print( $fh $md5 . pack($self->{long_pack}, $location) );
return $result;
}
seek($fh, $subloc + DBM::Deep->SIG_SIZE + $root->{file_offset}, SEEK_SET);
my $size;
- read( $fh, $size, $DATA_LENGTH_SIZE); $size = unpack($DATA_LENGTH_PACK, $size);
+ read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size);
##
# If value is a hash, array, or raw value with equal or less size, we can
}
else {
$location = $root->{end};
- seek($fh, $tag->{offset} + ($i * $BUCKET_SIZE) + $HASH_SIZE + $root->{file_offset}, SEEK_SET);
- print( $fh pack($LONG_PACK, $location) );
+ seek($fh, $tag->{offset} + ($i * $self->{bucket_size}) + $self->{hash_size} + $root->{file_offset}, SEEK_SET);
+ print( $fh pack($self->{long_pack}, $location) );
}
last;
##
if (!$location) {
seek($fh, $tag->{ref_loc} + $root->{file_offset}, SEEK_SET);
- print( $fh pack($LONG_PACK, $root->{end}) );
+ print( $fh pack($self->{long_pack}, $root->{end}) );
my $index_tag = $self->create_tag($obj, $root->{end}, DBM::Deep->SIG_INDEX, chr(0) x $self->{index_size});
my @offsets = ();
- $keys .= $md5 . pack($LONG_PACK, 0);
+ $keys .= $md5 . pack($self->{long_pack}, 0);
- for (my $i=0; $i<=$MAX_BUCKETS; $i++) {
- my $key = substr($keys, $i * $BUCKET_SIZE, $HASH_SIZE);
+ for (my $i=0; $i<=$self->{max_buckets}; $i++) {
+ my $key = substr($keys, $i * $self->{bucket_size}, $self->{hash_size});
if ($key) {
- my $old_subloc = unpack($LONG_PACK, substr($keys, ($i * $BUCKET_SIZE) +
- $HASH_SIZE, $LONG_SIZE));
+ my $old_subloc = unpack($self->{long_pack}, substr($keys, ($i * $self->{bucket_size}) +
+ $self->{hash_size}, $self->{long_size}));
my $num = ord(substr($key, $tag->{ch} + 1, 1));
if ($offsets[$num]) {
- my $offset = $offsets[$num] + DBM::Deep->SIG_SIZE + $DATA_LENGTH_SIZE;
+ my $offset = $offsets[$num] + DBM::Deep->SIG_SIZE + $self->{data_size};
seek($fh, $offset + $root->{file_offset}, SEEK_SET);
my $subkeys;
- read( $fh, $subkeys, $BUCKET_LIST_SIZE);
+ read( $fh, $subkeys, $self->{bucket_list_size});
- for (my $k=0; $k<$MAX_BUCKETS; $k++) {
- my $subloc = unpack($LONG_PACK, substr($subkeys, ($k * $BUCKET_SIZE) +
- $HASH_SIZE, $LONG_SIZE));
+ for (my $k=0; $k<$self->{max_buckets}; $k++) {
+ my $subloc = unpack($self->{long_pack}, substr($subkeys, ($k * $self->{bucket_size}) +
+ $self->{hash_size}, $self->{long_size}));
if (!$subloc) {
- seek($fh, $offset + ($k * $BUCKET_SIZE) + $root->{file_offset}, SEEK_SET);
- print( $fh $key . pack($LONG_PACK, $old_subloc || $root->{end}) );
+ seek($fh, $offset + ($k * $self->{bucket_size}) + $root->{file_offset}, SEEK_SET);
+ print( $fh $key . pack($self->{long_pack}, $old_subloc || $root->{end}) );
last;
}
} # k loop
}
else {
$offsets[$num] = $root->{end};
- seek($fh, $index_tag->{offset} + ($num * $LONG_SIZE) + $root->{file_offset}, SEEK_SET);
- print( $fh pack($LONG_PACK, $root->{end}) );
+ seek($fh, $index_tag->{offset} + ($num * $self->{long_size}) + $root->{file_offset}, SEEK_SET);
+ print( $fh pack($self->{long_pack}, $root->{end}) );
- my $blist_tag = $self->create_tag($obj, $root->{end}, DBM::Deep->SIG_BLIST, chr(0) x $BUCKET_LIST_SIZE);
+ my $blist_tag = $self->create_tag($obj, $root->{end}, DBM::Deep->SIG_BLIST, chr(0) x $self->{bucket_list_size});
seek($fh, $blist_tag->{offset} + $root->{file_offset}, SEEK_SET);
- print( $fh $key . pack($LONG_PACK, $old_subloc || $root->{end}) );
+ print( $fh $key . pack($self->{long_pack}, $old_subloc || $root->{end}) );
}
} # key is real
} # i loop
my $r = Scalar::Util::reftype($value) || '';
if ($r eq 'HASH') {
print( $fh DBM::Deep->TYPE_HASH );
- print( $fh pack($DATA_LENGTH_PACK, $self->{index_size}) . chr(0) x $self->{index_size} );
+ print( $fh pack($self->{data_pack}, $self->{index_size}) . chr(0) x $self->{index_size} );
$content_length = $self->{index_size};
}
elsif ($r eq 'ARRAY') {
print( $fh DBM::Deep->TYPE_ARRAY );
- print( $fh pack($DATA_LENGTH_PACK, $self->{index_size}) . chr(0) x $self->{index_size} );
+ print( $fh pack($self->{data_pack}, $self->{index_size}) . chr(0) x $self->{index_size} );
$content_length = $self->{index_size};
}
elsif (!defined($value)) {
print( $fh DBM::Deep->SIG_NULL );
- print( $fh pack($DATA_LENGTH_PACK, 0) );
+ print( $fh pack($self->{data_pack}, 0) );
$content_length = 0;
}
else {
print( $fh DBM::Deep->SIG_DATA );
- print( $fh pack($DATA_LENGTH_PACK, length($value)) . $value );
+ print( $fh pack($self->{data_pack}, length($value)) . $value );
$content_length = length($value);
}
##
# Plain key is stored AFTER value, as keys are typically fetched less often.
##
- print( $fh pack($DATA_LENGTH_PACK, length($plain_key)) . $plain_key );
+ print( $fh pack($self->{data_pack}, length($plain_key)) . $plain_key );
##
# If value is blessed, preserve class name
# Blessed ref -- will restore later
##
print( $fh chr(1) );
- print( $fh pack($DATA_LENGTH_PACK, length($value_class)) . $value_class );
+ print( $fh pack($self->{data_pack}, length($value_class)) . $value_class );
$content_length += 1;
- $content_length += $DATA_LENGTH_SIZE + length($value_class);
+ $content_length += $self->{data_size} + length($value_class);
}
else {
print( $fh chr(0) );
##
if ($location == $root->{end}) {
$root->{end} += DBM::Deep->SIG_SIZE;
- $root->{end} += $DATA_LENGTH_SIZE + $content_length;
- $root->{end} += $DATA_LENGTH_SIZE + length($plain_key);
+ $root->{end} += $self->{data_size} + $content_length;
+ $root->{end} += $self->{data_size} + length($plain_key);
}
##
}
sub get_bucket_value {
- ##
- # Fetch single value given tag and MD5 digested key.
- ##
- my $self = shift;
- my ($obj, $tag, $md5) = @_;
- my $keys = $tag->{content};
+ ##
+ # Fetch single value given tag and MD5 digested key.
+ ##
+ my $self = shift;
+ my ($obj, $tag, $md5) = @_;
+ my $keys = $tag->{content};
my $fh = $obj->_fh;
- ##
- # Iterate through buckets, looking for a key match
- ##
+ ##
+ # Iterate through buckets, looking for a key match
+ ##
BUCKET:
- for (my $i=0; $i<$MAX_BUCKETS; $i++) {
- my $key = substr($keys, $i * $BUCKET_SIZE, $HASH_SIZE);
- my $subloc = unpack($LONG_PACK, substr($keys, ($i * $BUCKET_SIZE) + $HASH_SIZE, $LONG_SIZE));
+ for (my $i=0; $i<$self->{max_buckets}; $i++) {
+ my $key = substr($keys, $i * $self->{bucket_size}, $self->{hash_size});
+ my $subloc = unpack($self->{long_pack}, substr($keys, ($i * $self->{bucket_size}) + $self->{hash_size}, $self->{long_size}));
- if (!$subloc) {
- ##
- # Hit end of list, no match
- ##
- return;
- }
+ if (!$subloc) {
+ ##
+ # Hit end of list, no match
+ ##
+ return;
+ }
if ( $md5 ne $key ) {
next BUCKET;
my $signature;
seek($fh, $subloc + $obj->_root->{file_offset}, SEEK_SET);
read( $fh, $signature, DBM::Deep->SIG_SIZE);
-
+
##
# If value is a hash or array, return new DBM::Deep object with correct offset
##
base_offset => $subloc,
root => $obj->_root,
);
-
+
if ($obj->_root->{autobless}) {
##
# Skip over value and plain key to see if object needs
# to be re-blessed
##
- seek($fh, $DATA_LENGTH_SIZE + $self->{index_size}, SEEK_CUR);
-
+ seek($fh, $self->{data_size} + $self->{index_size}, SEEK_CUR);
+
my $size;
- read( $fh, $size, $DATA_LENGTH_SIZE); $size = unpack($DATA_LENGTH_PACK, $size);
+ read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size);
if ($size) { seek($fh, $size, SEEK_CUR); }
-
+
my $bless_bit;
read( $fh, $bless_bit, 1);
if (ord($bless_bit)) {
# Yes, object needs to be re-blessed
##
my $class_name;
- read( $fh, $size, $DATA_LENGTH_SIZE); $size = unpack($DATA_LENGTH_PACK, $size);
+ 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 ); }
}
}
-
+
return $obj;
}
-
+
##
# Otherwise return actual value
##
elsif ($signature eq DBM::Deep->SIG_DATA) {
my $size;
my $value = '';
- read( $fh, $size, $DATA_LENGTH_SIZE); $size = unpack($DATA_LENGTH_PACK, $size);
+ read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size);
if ($size) { read( $fh, $value, $size); }
return $value;
}
-
+
##
# Key exists, but content is null
##
else { return; }
- } # i loop
+ } # i loop
- return;
+ return;
}
sub delete_bucket {
- ##
- # Delete single key/value pair given tag and MD5 digested key.
- ##
- my $self = shift;
- my ($obj, $tag, $md5) = @_;
- my $keys = $tag->{content};
+ ##
+ # Delete single key/value pair given tag and MD5 digested key.
+ ##
+ my $self = shift;
+ my ($obj, $tag, $md5) = @_;
+ my $keys = $tag->{content};
my $fh = $obj->_fh;
-
- ##
- # Iterate through buckets, looking for a key match
- ##
+
+ ##
+ # Iterate through buckets, looking for a key match
+ ##
BUCKET:
- for (my $i=0; $i<$MAX_BUCKETS; $i++) {
- my $key = substr($keys, $i * $BUCKET_SIZE, $HASH_SIZE);
- my $subloc = unpack($LONG_PACK, substr($keys, ($i * $BUCKET_SIZE) + $HASH_SIZE, $LONG_SIZE));
+ for (my $i=0; $i<$self->{max_buckets}; $i++) {
+ my $key = substr($keys, $i * $self->{bucket_size}, $self->{hash_size});
+ my $subloc = unpack($self->{long_pack}, substr($keys, ($i * $self->{bucket_size}) + $self->{hash_size}, $self->{long_size}));
- if (!$subloc) {
- ##
- # Hit end of list, no match
- ##
- return;
- }
+ if (!$subloc) {
+ ##
+ # Hit end of list, no match
+ ##
+ return;
+ }
if ( $md5 ne $key ) {
next BUCKET;
##
# Matched key -- delete bucket and return
##
- seek($fh, $tag->{offset} + ($i * $BUCKET_SIZE) + $obj->_root->{file_offset}, SEEK_SET);
- print( $fh substr($keys, ($i+1) * $BUCKET_SIZE ) );
- print( $fh chr(0) x $BUCKET_SIZE );
-
+ seek($fh, $tag->{offset} + ($i * $self->{bucket_size}) + $obj->_root->{file_offset}, SEEK_SET);
+ print( $fh substr($keys, ($i+1) * $self->{bucket_size} ) );
+ print( $fh chr(0) x $self->{bucket_size} );
+
return 1;
- } # i loop
+ } # i loop
- return;
+ return;
}
sub bucket_exists {
- ##
- # Check existence of single key given tag and MD5 digested key.
- ##
- my $self = shift;
- my ($obj, $tag, $md5) = @_;
- my $keys = $tag->{content};
-
- ##
- # Iterate through buckets, looking for a key match
- ##
+ ##
+ # Check existence of single key given tag and MD5 digested key.
+ ##
+ my $self = shift;
+ my ($obj, $tag, $md5) = @_;
+ my $keys = $tag->{content};
+
+ ##
+ # Iterate through buckets, looking for a key match
+ ##
BUCKET:
- for (my $i=0; $i<$MAX_BUCKETS; $i++) {
- my $key = substr($keys, $i * $BUCKET_SIZE, $HASH_SIZE);
- my $subloc = unpack($LONG_PACK, substr($keys, ($i * $BUCKET_SIZE) + $HASH_SIZE, $LONG_SIZE));
+ for (my $i=0; $i<$self->{max_buckets}; $i++) {
+ my $key = substr($keys, $i * $self->{bucket_size}, $self->{hash_size});
+ my $subloc = unpack($self->{long_pack}, substr($keys, ($i * $self->{bucket_size}) + $self->{hash_size}, $self->{long_size}));
- if (!$subloc) {
- ##
- # Hit end of list, no match
- ##
- return;
- }
+ if (!$subloc) {
+ ##
+ # Hit end of list, no match
+ ##
+ return;
+ }
if ( $md5 ne $key ) {
next BUCKET;
# Matched key -- return true
##
return 1;
- } # i loop
+ } # i loop
- return;
+ return;
}
sub find_bucket_list {
- ##
- # Locate offset for bucket list, given digested key
- ##
- my $self = shift;
- my ($obj, $md5) = @_;
-
- ##
- # Locate offset for bucket list using digest index system
- ##
- my $ch = 0;
- my $tag = $self->load_tag($obj, $obj->_base_offset);
- if (!$tag) { return; }
-
- while ($tag->{signature} ne DBM::Deep->SIG_BLIST) {
- $tag = $self->index_lookup($obj, $tag, ord(substr($md5, $ch, 1)));
- if (!$tag) { return; }
- $ch++;
- }
-
- return $tag;
+ ##
+ # Locate offset for bucket list, given digested key
+ ##
+ my $self = shift;
+ my ($obj, $md5, $args) = @_;
+ $args = {} unless $args;
+
+ ##
+ # Locate offset for bucket list using digest index system
+ ##
+ my $ch = 0;
+ my $tag = $self->load_tag($obj, $obj->_base_offset);
+ if (!$tag) {
+ return $self->_throw_error( "INTERNAL ERROR - Cannot find tag" );
+ }
+
+ while ($tag->{signature} ne DBM::Deep->SIG_BLIST) {
+ my $num = ord substr($md5, $ch, 1);
+
+ my $ref_loc = $tag->{offset} + ($num * $self->{long_size});
+ $tag = $self->index_lookup( $obj, $tag, $num );
+
+ if (!$tag) {
+ if ( $args->{create} ) {
+ my $fh = $obj->_fh;
+ seek($fh, $ref_loc + $obj->_root->{file_offset}, SEEK_SET);
+ print( $fh pack($self->{long_pack}, $obj->_root->{end}) );
+
+ $tag = $self->create_tag(
+ $obj, $obj->_root->{end},
+ DBM::Deep->SIG_BLIST,
+ chr(0) x $self->{bucket_list_size},
+ );
+
+ $tag->{ref_loc} = $ref_loc;
+ $tag->{ch} = $ch;
+
+ last;
+ }
+ else {
+ return;
+ }
+ }
+
+ $tag->{ch} = $ch;
+ $tag->{ref_loc} = $ref_loc;
+
+ $ch++;
+ }
+
+ return $tag;
+}
+
+sub index_lookup {
+ ##
+ # Given index tag, lookup single entry in index and return .
+ ##
+ my $self = shift;
+ my ($obj, $tag, $index) = @_;
+
+ my $location = unpack(
+ $self->{long_pack},
+ substr(
+ $tag->{content},
+ $index * $self->{long_size},
+ $self->{long_size},
+ ),
+ );
+
+ if (!$location) { return; }
+
+ return $self->load_tag( $obj, $location );
}
sub traverse_index {
- ##
- # Scan index and recursively step into deeper levels, looking for next key.
- ##
+ ##
+ # Scan index and recursively step into deeper levels, looking for next key.
+ ##
my $self = shift;
my ($obj, $offset, $ch, $force_return_next) = @_;
$force_return_next = undef unless $force_return_next;
-
- my $tag = $self->load_tag($obj, $offset );
+
+ my $tag = $self->load_tag($obj, $offset );
my $fh = $obj->_fh;
-
- if ($tag->{signature} ne DBM::Deep->SIG_BLIST) {
- my $content = $tag->{content};
- my $start;
- if ($obj->{return_next}) { $start = 0; }
- else { $start = ord(substr($obj->{prev_md5}, $ch, 1)); }
-
- for (my $index = $start; $index < 256; $index++) {
- my $subloc = unpack($LONG_PACK, substr($content, $index * $LONG_SIZE, $LONG_SIZE) );
- if ($subloc) {
- my $result = $self->traverse_index( $obj, $subloc, $ch + 1, $force_return_next );
- if (defined($result)) { return $result; }
- }
- } # index loop
-
- $obj->{return_next} = 1;
- } # tag is an index
-
- elsif ($tag->{signature} eq DBM::Deep->SIG_BLIST) {
- my $keys = $tag->{content};
- if ($force_return_next) { $obj->{return_next} = 1; }
-
- ##
- # Iterate through buckets, looking for a key match
- ##
- for (my $i=0; $i<$MAX_BUCKETS; $i++) {
- my $key = substr($keys, $i * $BUCKET_SIZE, $HASH_SIZE);
- my $subloc = unpack($LONG_PACK, substr($keys, ($i * $BUCKET_SIZE) + $HASH_SIZE, $LONG_SIZE));
-
- if (!$subloc) {
- ##
- # End of bucket list -- return to outer loop
- ##
- $obj->{return_next} = 1;
- last;
- }
- elsif ($key eq $obj->{prev_md5}) {
- ##
- # Located previous key -- return next one found
- ##
- $obj->{return_next} = 1;
- next;
- }
- elsif ($obj->{return_next}) {
- ##
- # Seek to bucket location and skip over signature
- ##
- seek($fh, $subloc + DBM::Deep->SIG_SIZE + $obj->_root->{file_offset}, SEEK_SET);
-
- ##
- # Skip over value to get to plain key
- ##
- my $size;
- read( $fh, $size, $DATA_LENGTH_SIZE); $size = unpack($DATA_LENGTH_PACK, $size);
- if ($size) { seek($fh, $size, SEEK_CUR); }
-
- ##
- # Read in plain key and return as scalar
- ##
- my $plain_key;
- read( $fh, $size, $DATA_LENGTH_SIZE); $size = unpack($DATA_LENGTH_PACK, $size);
- if ($size) { read( $fh, $plain_key, $size); }
-
- return $plain_key;
- }
- } # bucket loop
-
- $obj->{return_next} = 1;
- } # tag is a bucket list
-
- return;
+
+ if ($tag->{signature} ne DBM::Deep->SIG_BLIST) {
+ my $content = $tag->{content};
+ my $start;
+ if ($obj->{return_next}) { $start = 0; }
+ else { $start = ord(substr($obj->{prev_md5}, $ch, 1)); }
+
+ for (my $index = $start; $index < 256; $index++) {
+ my $subloc = unpack($self->{long_pack}, substr($content, $index * $self->{long_size}, $self->{long_size}) );
+ if ($subloc) {
+ my $result = $self->traverse_index( $obj, $subloc, $ch + 1, $force_return_next );
+ if (defined($result)) { return $result; }
+ }
+ } # index loop
+
+ $obj->{return_next} = 1;
+ } # tag is an index
+
+ elsif ($tag->{signature} eq DBM::Deep->SIG_BLIST) {
+ my $keys = $tag->{content};
+ if ($force_return_next) { $obj->{return_next} = 1; }
+
+ ##
+ # Iterate through buckets, looking for a key match
+ ##
+ for (my $i=0; $i<$self->{max_buckets}; $i++) {
+ my $key = substr($keys, $i * $self->{bucket_size}, $self->{hash_size});
+ my $subloc = unpack($self->{long_pack}, substr($keys, ($i * $self->{bucket_size}) + $self->{hash_size}, $self->{long_size}));
+
+ if (!$subloc) {
+ ##
+ # End of bucket list -- return to outer loop
+ ##
+ $obj->{return_next} = 1;
+ last;
+ }
+ elsif ($key eq $obj->{prev_md5}) {
+ ##
+ # Located previous key -- return next one found
+ ##
+ $obj->{return_next} = 1;
+ next;
+ }
+ elsif ($obj->{return_next}) {
+ ##
+ # Seek to bucket location and skip over signature
+ ##
+ seek($fh, $subloc + DBM::Deep->SIG_SIZE + $obj->_root->{file_offset}, SEEK_SET);
+
+ ##
+ # Skip over value to get to plain key
+ ##
+ my $size;
+ read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size);
+ if ($size) { seek($fh, $size, SEEK_CUR); }
+
+ ##
+ # Read in plain key and return as scalar
+ ##
+ my $plain_key;
+ read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size);
+ if ($size) { read( $fh, $plain_key, $size); }
+
+ return $plain_key;
+ }
+ } # bucket loop
+
+ $obj->{return_next} = 1;
+ } # tag is a bucket list
+
+ return;
}
sub get_next_key {
- ##
- # Locate next key, given digested previous one
- ##
+ ##
+ # Locate next key, given digested previous one
+ ##
my $self = shift;
my ($obj) = @_;
-
- $obj->{prev_md5} = $_[1] ? $_[1] : undef;
- $obj->{return_next} = 0;
-
- ##
- # If the previous key was not specifed, start at the top and
- # return the first one found.
- ##
- if (!$obj->{prev_md5}) {
- $obj->{prev_md5} = chr(0) x $HASH_SIZE;
- $obj->{return_next} = 1;
- }
-
- return $self->traverse_index( $obj, $obj->_base_offset, 0 );
+
+ $obj->{prev_md5} = $_[1] ? $_[1] : undef;
+ $obj->{return_next} = 0;
+
+ ##
+ # If the previous key was not specifed, start at the top and
+ # return the first one found.
+ ##
+ if (!$obj->{prev_md5}) {
+ $obj->{prev_md5} = chr(0) x $self->{hash_size};
+ $obj->{return_next} = 1;
+ }
+
+ return $self->traverse_index( $obj, $obj->_base_offset, 0 );
}
1;
projects / dbsrgits/DBM-Deep.git / blobdiff