/usr/share/perl5/DBM/Deep/Sector/File/BucketList.pm is in libdbm-deep-perl 2.0002-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 | package DBM::Deep::Sector::File::BucketList;
use 5.008_004;
use strict;
use warnings FATAL => 'all';
use base qw( DBM::Deep::Sector::File );
my $STALE_SIZE = 2;
# Please refer to the pack() documentation for further information
my %StP = (
1 => 'C', # Unsigned char value (no order needed as it's just one byte)
2 => 'n', # Unsigned short in "network" (big-endian) order
4 => 'N', # Unsigned long in "network" (big-endian) order
8 => 'Q', # Usigned quad (no order specified, presumably machine-dependent)
);
sub _init {
my $self = shift;
my $engine = $self->engine;
unless ( $self->offset ) {
my $leftover = $self->size - $self->base_size;
$self->{offset} = $engine->_request_blist_sector( $self->size );
$engine->storage->print_at( $self->offset, $engine->SIG_BLIST ); # Sector type
# Skip staleness counter
$engine->storage->print_at( $self->offset + $self->base_size,
chr(0) x $leftover, # Zero-fill the data
);
}
if ( $self->{key_md5} ) {
$self->find_md5;
}
return $self;
}
sub wipe {
my $self = shift;
$self->engine->storage->print_at( $self->offset + $self->base_size,
chr(0) x ($self->size - $self->base_size), # Zero-fill the data
);
}
sub size {
my $self = shift;
unless ( $self->{size} ) {
my $e = $self->engine;
# Base + numbuckets * bucketsize
$self->{size} = $self->base_size + $e->max_buckets * $self->bucket_size;
}
return $self->{size};
}
sub free_meth { '_add_free_blist_sector' }
sub free {
my $self = shift;
my $e = $self->engine;
foreach my $bucket ( $self->chopped_up ) {
my $rest = $bucket->[-1];
# Delete the keysector
my $l = unpack( $StP{$e->byte_size}, substr( $rest, $e->hash_size, $e->byte_size ) );
my $s = $e->load_sector( $l ); $s->free if $s;
# Delete the HEAD sector
$l = unpack( $StP{$e->byte_size},
substr( $rest,
$e->hash_size + $e->byte_size,
$e->byte_size,
),
);
$s = $e->load_sector( $l ); $s->free if $s;
foreach my $txn ( 0 .. $e->num_txns - 2 ) {
my $l = unpack( $StP{$e->byte_size},
substr( $rest,
$e->hash_size + 2 * $e->byte_size + $txn * ($e->byte_size + $STALE_SIZE),
$e->byte_size,
),
);
my $s = $e->load_sector( $l ); $s->free if $s;
}
}
$self->SUPER::free();
}
sub bucket_size {
my $self = shift;
unless ( $self->{bucket_size} ) {
my $e = $self->engine;
# Key + head (location) + transactions (location + staleness-counter)
my $location_size = $e->byte_size + $e->byte_size + ($e->num_txns - 1) * ($e->byte_size + $STALE_SIZE);
$self->{bucket_size} = $e->hash_size + $location_size;
}
return $self->{bucket_size};
}
# XXX This is such a poor hack. I need to rethink this code.
sub chopped_up {
my $self = shift;
my $e = $self->engine;
my @buckets;
foreach my $idx ( 0 .. $e->max_buckets - 1 ) {
my $spot = $self->offset + $self->base_size + $idx * $self->bucket_size;
my $md5 = $e->storage->read_at( $spot, $e->hash_size );
#XXX If we're chopping, why would we ever have the blank_md5?
last if $md5 eq $e->blank_md5;
my $rest = $e->storage->read_at( undef, $self->bucket_size - $e->hash_size );
push @buckets, [ $spot, $md5 . $rest ];
}
return @buckets;
}
sub write_at_next_open {
my $self = shift;
my ($entry) = @_;
#XXX This is such a hack!
$self->{_next_open} = 0 unless exists $self->{_next_open};
my $spot = $self->offset + $self->base_size + $self->{_next_open}++ * $self->bucket_size;
$self->engine->storage->print_at( $spot, $entry );
return $spot;
}
sub has_md5 {
my $self = shift;
unless ( exists $self->{found} ) {
$self->find_md5;
}
return $self->{found};
}
sub find_md5 {
my $self = shift;
$self->{found} = undef;
$self->{idx} = -1;
if ( @_ ) {
$self->{key_md5} = shift;
}
# If we don't have an MD5, then what are we supposed to do?
unless ( exists $self->{key_md5} ) {
DBM::Deep->_throw_error( "Cannot find_md5 without a key_md5 set" );
}
my $e = $self->engine;
foreach my $idx ( 0 .. $e->max_buckets - 1 ) {
my $potential = $e->storage->read_at(
$self->offset + $self->base_size + $idx * $self->bucket_size, $e->hash_size,
);
if ( $potential eq $e->blank_md5 ) {
$self->{idx} = $idx;
return;
}
if ( $potential eq $self->{key_md5} ) {
$self->{found} = 1;
$self->{idx} = $idx;
return;
}
}
return;
}
sub write_md5 {
my $self = shift;
my ($args) = @_;
DBM::Deep->_throw_error( "write_md5: no key" ) unless exists $args->{key};
DBM::Deep->_throw_error( "write_md5: no key_md5" ) unless exists $args->{key_md5};
DBM::Deep->_throw_error( "write_md5: no value" ) unless exists $args->{value};
my $engine = $self->engine;
$args->{trans_id} = $engine->trans_id unless exists $args->{trans_id};
my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size;
$engine->add_entry( $args->{trans_id}, $spot );
unless ($self->{found}) {
my $key_sector = DBM::Deep::Sector::File::Scalar->new({
engine => $engine,
data => $args->{key},
});
$engine->storage->print_at( $spot,
$args->{key_md5},
pack( $StP{$engine->byte_size}, $key_sector->offset ),
);
}
my $loc = $spot
+ $engine->hash_size
+ $engine->byte_size;
if ( $args->{trans_id} ) {
$loc += $engine->byte_size + ($args->{trans_id} - 1) * ( $engine->byte_size + $STALE_SIZE );
$engine->storage->print_at( $loc,
pack( $StP{$engine->byte_size}, $args->{value}->offset ),
pack( $StP{$STALE_SIZE}, $engine->get_txn_staleness_counter( $args->{trans_id} ) ),
);
}
else {
$engine->storage->print_at( $loc,
pack( $StP{$engine->byte_size}, $args->{value}->offset ),
);
}
}
sub mark_deleted {
my $self = shift;
my ($args) = @_;
$args ||= {};
my $engine = $self->engine;
$args->{trans_id} = $engine->trans_id unless exists $args->{trans_id};
my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size;
$engine->add_entry( $args->{trans_id}, $spot );
my $loc = $spot
+ $engine->hash_size
+ $engine->byte_size;
if ( $args->{trans_id} ) {
$loc += $engine->byte_size + ($args->{trans_id} - 1) * ( $engine->byte_size + $STALE_SIZE );
$engine->storage->print_at( $loc,
pack( $StP{$engine->byte_size}, 1 ), # 1 is the marker for deleted
pack( $StP{$STALE_SIZE}, $engine->get_txn_staleness_counter( $args->{trans_id} ) ),
);
}
else {
$engine->storage->print_at( $loc,
pack( $StP{$engine->byte_size}, 1 ), # 1 is the marker for deleted
);
}
}
sub delete_md5 {
my $self = shift;
my ($args) = @_;
my $engine = $self->engine;
return undef unless $self->{found};
# Save the location so that we can free the data
my $location = $self->get_data_location_for({
allow_head => 0,
});
my $key_sector = $self->get_key_for;
my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size;
$engine->storage->print_at( $spot,
$engine->storage->read_at(
$spot + $self->bucket_size,
$self->bucket_size * ( $engine->max_buckets - $self->{idx} - 1 ),
),
chr(0) x $self->bucket_size,
);
$key_sector->free;
my $data_sector = $self->engine->load_sector( $location );
my $data = $data_sector->data({ export => 1 });
$data_sector->free;
return $data;
}
sub get_data_location_for {
my $self = shift;
my ($args) = @_;
$args ||= {};
$args->{allow_head} = 0 unless exists $args->{allow_head};
$args->{trans_id} = $self->engine->trans_id unless exists $args->{trans_id};
$args->{idx} = $self->{idx} unless exists $args->{idx};
my $e = $self->engine;
my $spot = $self->offset + $self->base_size
+ $args->{idx} * $self->bucket_size
+ $e->hash_size
+ $e->byte_size;
if ( $args->{trans_id} ) {
$spot += $e->byte_size + ($args->{trans_id} - 1) * ( $e->byte_size + $STALE_SIZE );
}
my $buffer = $e->storage->read_at(
$spot,
$e->byte_size + $STALE_SIZE,
);
my ($loc, $staleness) = unpack( $StP{$e->byte_size} . ' ' . $StP{$STALE_SIZE}, $buffer );
# XXX Merge the two if-clauses below
if ( $args->{trans_id} ) {
# We have found an entry that is old, so get rid of it
if ( $staleness != (my $s = $e->get_txn_staleness_counter( $args->{trans_id} ) ) ) {
$e->storage->print_at(
$spot,
pack( $StP{$e->byte_size} . ' ' . $StP{$STALE_SIZE}, (0) x 2 ),
);
$loc = 0;
}
}
# If we're in a transaction and we never wrote to this location, try the
# HEAD instead.
if ( $args->{trans_id} && !$loc && $args->{allow_head} ) {
return $self->get_data_location_for({
trans_id => 0,
allow_head => 1,
idx => $args->{idx},
});
}
return $loc <= 1 ? 0 : $loc;
}
sub get_data_for {
my $self = shift;
my ($args) = @_;
$args ||= {};
return unless $self->{found};
my $location = $self->get_data_location_for({
allow_head => $args->{allow_head},
});
return $self->engine->load_sector( $location );
}
sub get_key_for {
my $self = shift;
my ($idx) = @_;
$idx = $self->{idx} unless defined $idx;
if ( $idx >= $self->engine->max_buckets ) {
DBM::Deep->_throw_error( "get_key_for(): Attempting to retrieve $idx" );
}
my $location = $self->engine->storage->read_at(
$self->offset + $self->base_size + $idx * $self->bucket_size + $self->engine->hash_size,
$self->engine->byte_size,
);
$location = unpack( $StP{$self->engine->byte_size}, $location );
DBM::Deep->_throw_error( "get_key_for: No location?" ) unless $location;
return $self->engine->load_sector( $location );
}
1;
__END__
|