package DBM::Deep::10002;
use 5.006_000;
use strict;
use warnings;
our $VERSION = q(1.0002);
use Fcntl qw( :flock );
use Clone ();
use Digest::MD5 ();
use FileHandle::Fmode ();
use Scalar::Util ();
#use DBM::Deep::10002::Engine;
#use DBM::Deep::10002::File;
##
# Setup constants for users to pass to new()
##
sub TYPE_HASH () { DBM::Deep::10002::Engine->SIG_HASH }
sub TYPE_ARRAY () { DBM::Deep::10002::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) {
$class = 'DBM::Deep::10002::Array';
#require DBM::Deep::10002::Array;
tie @$self, $class, %$args;
}
else {
$class = 'DBM::Deep::10002::Hash';
#require DBM::Deep::10002::Hash;
tie %$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::10002::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;
$args->{engine} = DBM::Deep::10002::Engine->new( { %{$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::10002::Hash;
return DBM::Deep::10002::Hash->TIEHASH( @_ );
}
sub TIEARRAY {
shift;
#require DBM::Deep::10002::Array;
return DBM::Deep::10002::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::10002' ) } ) {
${$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 $temp;
}
sub import {
##
# Recursively import Perl hash/array structure
##
if (!ref($_[0])) { return; } # Perl calls import() on use -- ignore
my $self = shift->_get_self;
my ($struct) = @_;
# struct is not a reference, so just import based on our type
if (!ref($struct)) {
$struct = $self->_repr( @_ );
}
#XXX This isn't the best solution. Better would be to use Data::Walker,
#XXX but that's a lot more thinking than I want to do right now.
eval {
local $SIG{'__DIE__'};
$self->_import( Clone::clone( $struct ) );
}; if ( my $e = $@ ) {
die $e;
}
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?
my $db_temp = DBM::Deep::10002->new(
file => $self->_storage->{file} . '.tmp',
type => $self->_type,
# Bring over all the parameters that we need to bring over
num_txns => $self->_engine->num_txns,
byte_size => $self->_engine->byte_size,
max_buckets => $self->_engine->max_buckets,
);
$self->lock();
$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::10002->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 {
##
# Setup filter function for storing or fetching the key or value
##
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 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 {
die "DBM::Deep::10002: $_[1]\n";
my $n = 0;
while( 1 ) {
my @caller = caller( ++$n );
next if $caller[0] =~ m/^DBM::Deep::10002/;
die "DBM::Deep::10002: $_[1] at $0 line $caller[2]\n";
last;
}
}
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( @_ ) }
package DBM::Deep::10002::Array;
use 5.006_000;
use strict;
use warnings;
our $VERSION = q(1.0002);
# This is to allow DBM::Deep::10002::Array to handle negative indices on
# its own. Otherwise, Perl would intercept the call to negative
# indices for us. This was causing bugs for negative index handling.
our $NEGATIVE_INDICES = 1;
use base 'DBM::Deep::10002';
use Scalar::Util ();
sub _get_self {
eval { local $SIG{'__DIE__'}; tied( @{$_[0]} ) } || $_[0]
}
sub _repr { shift;[ @_ ] }
sub _import {
my $self = shift;
my ($struct) = @_;
$self->push( @$struct );
return 1;
}
sub TIEARRAY {
my $class = shift;
my $args = $class->_get_args( @_ );
$args->{type} = $class->TYPE_ARRAY;
return $class->_init($args);
}
sub FETCH {
my $self = shift->_get_self;
my ($key) = @_;
$self->lock( $self->LOCK_SH );
if ( !defined $key ) {
DBM::Deep::10002->_throw_error( "Cannot use an undefined array index." );
}
elsif ( $key =~ /^-?\d+$/ ) {
if ( $key < 0 ) {
$key += $self->FETCHSIZE;
unless ( $key >= 0 ) {
$self->unlock;
return;
}
}
}
elsif ( $key ne 'length' ) {
$self->unlock;
DBM::Deep::10002->_throw_error( "Cannot use '$key' as an array index." );
}
my $rv = $self->SUPER::FETCH( $key );
$self->unlock;
return $rv;
}
sub STORE {
my $self = shift->_get_self;
my ($key, $value) = @_;
$self->lock( $self->LOCK_EX );
my $size;
my $idx_is_numeric;
if ( !defined $key ) {
DBM::Deep::10002->_throw_error( "Cannot use an undefined array index." );
}
elsif ( $key =~ /^-?\d+$/ ) {
$idx_is_numeric = 1;
if ( $key < 0 ) {
$size = $self->FETCHSIZE;
if ( $key + $size < 0 ) {
die( "Modification of non-creatable array value attempted, subscript $key" );
}
$key += $size
}
}
elsif ( $key ne 'length' ) {
$self->unlock;
DBM::Deep::10002->_throw_error( "Cannot use '$key' as an array index." );
}
my $rv = $self->SUPER::STORE( $key, $value );
if ( $idx_is_numeric ) {
$size = $self->FETCHSIZE unless defined $size;
if ( $key >= $size ) {
$self->STORESIZE( $key + 1 );
}
}
$self->unlock;
return $rv;
}
sub EXISTS {
my $self = shift->_get_self;
my ($key) = @_;
$self->lock( $self->LOCK_SH );
if ( !defined $key ) {
DBM::Deep::10002->_throw_error( "Cannot use an undefined array index." );
}
elsif ( $key =~ /^-?\d+$/ ) {
if ( $key < 0 ) {
$key += $self->FETCHSIZE;
unless ( $key >= 0 ) {
$self->unlock;
return;
}
}
}
elsif ( $key ne 'length' ) {
$self->unlock;
DBM::Deep::10002->_throw_error( "Cannot use '$key' as an array index." );
}
my $rv = $self->SUPER::EXISTS( $key );
$self->unlock;
return $rv;
}
sub DELETE {
my $self = shift->_get_self;
my ($key) = @_;
$self->lock( $self->LOCK_EX );
my $size = $self->FETCHSIZE;
if ( !defined $key ) {
DBM::Deep::10002->_throw_error( "Cannot use an undefined array index." );
}
elsif ( $key =~ /^-?\d+$/ ) {
if ( $key < 0 ) {
$key += $size;
unless ( $key >= 0 ) {
$self->unlock;
return;
}
}
}
elsif ( $key ne 'length' ) {
$self->unlock;
DBM::Deep::10002->_throw_error( "Cannot use '$key' as an array index." );
}
my $rv = $self->SUPER::DELETE( $key );
if ($rv && $key == $size - 1) {
$self->STORESIZE( $key );
}
$self->unlock;
return $rv;
}
# Now that we have a real Reference sector, we should store arrayzize there. However,
# arraysize needs to be transactionally-aware, so a simple location to store it isn't
# going to work.
sub FETCHSIZE {
my $self = shift->_get_self;
$self->lock( $self->LOCK_SH );
my $SAVE_FILTER = $self->_storage->{filter_fetch_value};
$self->_storage->{filter_fetch_value} = undef;
my $size = $self->FETCH('length') || 0;
$self->_storage->{filter_fetch_value} = $SAVE_FILTER;
$self->unlock;
return $size;
}
sub STORESIZE {
my $self = shift->_get_self;
my ($new_length) = @_;
$self->lock( $self->LOCK_EX );
my $SAVE_FILTER = $self->_storage->{filter_store_value};
$self->_storage->{filter_store_value} = undef;
my $result = $self->STORE('length', $new_length, 'length');
$self->_storage->{filter_store_value} = $SAVE_FILTER;
$self->unlock;
return $result;
}
sub POP {
my $self = shift->_get_self;
$self->lock( $self->LOCK_EX );
my $length = $self->FETCHSIZE();
if ($length) {
my $content = $self->FETCH( $length - 1 );
$self->DELETE( $length - 1 );
$self->unlock;
return $content;
}
else {
$self->unlock;
return;
}
}
sub PUSH {
my $self = shift->_get_self;
$self->lock( $self->LOCK_EX );
my $length = $self->FETCHSIZE();
while (my $content = shift @_) {
$self->STORE( $length, $content );
$length++;
}
$self->unlock;
return $length;
}
# XXX This really needs to be something more direct within the file, not a
# fetch and re-store. -RobK, 2007-09-20
sub _move_value {
my $self = shift;
my ($old_key, $new_key) = @_;
my $val = $self->FETCH( $old_key );
if ( eval { local $SIG{'__DIE__'}; $val->isa( 'DBM::Deep::10002::Hash' ) } ) {
$self->STORE( $new_key, { %$val } );
}
elsif ( eval { local $SIG{'__DIE__'}; $val->isa( 'DBM::Deep::10002::Array' ) } ) {
$self->STORE( $new_key, [ @$val ] );
}
else {
$self->STORE( $new_key, $val );
}
}
sub SHIFT {
my $self = shift->_get_self;
$self->lock( $self->LOCK_EX );
my $length = $self->FETCHSIZE();
if ($length) {
my $content = $self->FETCH( 0 );
for (my $i = 0; $i < $length - 1; $i++) {
$self->_move_value( $i+1, $i );
}
$self->DELETE( $length - 1 );
$self->unlock;
return $content;
}
else {
$self->unlock;
return;
}
}
sub UNSHIFT {
my $self = shift->_get_self;
my @new_elements = @_;
$self->lock( $self->LOCK_EX );
my $length = $self->FETCHSIZE();
my $new_size = scalar @new_elements;
if ($length) {
for (my $i = $length - 1; $i >= 0; $i--) {
$self->_move_value( $i, $i+$new_size );
}
}
for (my $i = 0; $i < $new_size; $i++) {
$self->STORE( $i, $new_elements[$i] );
}
$self->unlock;
return $length + $new_size;
}
sub SPLICE {
my $self = shift->_get_self;
$self->lock( $self->LOCK_EX );
my $length = $self->FETCHSIZE();
##
# Calculate offset and length of splice
##
my $offset = shift;
$offset = 0 unless defined $offset;
if ($offset < 0) { $offset += $length; }
my $splice_length;
if (scalar @_) { $splice_length = shift; }
else { $splice_length = $length - $offset; }
if ($splice_length < 0) { $splice_length += ($length - $offset); }
##
# Setup array with new elements, and copy out old elements for return
##
my @new_elements = @_;
my $new_size = scalar @new_elements;
my @old_elements = map {
$self->FETCH( $_ )
} $offset .. ($offset + $splice_length - 1);
##
# Adjust array length, and shift elements to accomodate new section.
##
if ( $new_size != $splice_length ) {
if ($new_size > $splice_length) {
for (my $i = $length - 1; $i >= $offset + $splice_length; $i--) {
$self->_move_value( $i, $i + ($new_size - $splice_length) );
}
}
else {
for (my $i = $offset + $splice_length; $i < $length; $i++) {
$self->_move_value( $i, $i + ($new_size - $splice_length) );
}
for (my $i = 0; $i < $splice_length - $new_size; $i++) {
$self->DELETE( $length - 1 );
$length--;
}
}
}
##
# Insert new elements into array
##
for (my $i = $offset; $i < $offset + $new_size; $i++) {
$self->STORE( $i, shift @new_elements );
}
$self->unlock;
##
# Return deleted section, or last element in scalar context.
##
return wantarray ? @old_elements : $old_elements[-1];
}
# We don't need to populate it, yet.
# It will be useful, though, when we split out HASH and ARRAY
sub EXTEND {
##
# Perl will call EXTEND() when the array is likely to grow.
# We don't care, but include it because it gets called at times.
##
}
sub _copy_node {
my $self = shift;
my ($db_temp) = @_;
my $length = $self->length();
for (my $index = 0; $index < $length; $index++) {
my $value = $self->get($index);
$self->_copy_value( \$db_temp->[$index], $value );
}
return 1;
}
##
# Public method aliases
##
sub length { (shift)->FETCHSIZE(@_) }
sub pop { (shift)->POP(@_) }
sub push { (shift)->PUSH(@_) }
sub unshift { (shift)->UNSHIFT(@_) }
sub splice { (shift)->SPLICE(@_) }
# This must be last otherwise we have to qualify all other calls to shift
# as calls to CORE::shift
sub shift { (CORE::shift)->SHIFT(@_) }
package DBM::Deep::10002::Hash;
use 5.006_000;
use strict;
use warnings;
our $VERSION = q(1.0002);
use base 'DBM::Deep::10002';
sub _get_self {
eval { local $SIG{'__DIE__'}; tied( %{$_[0]} ) } || $_[0]
}
#XXX Need to add a check here for @_ % 2
sub _repr { shift;return { @_ } }
sub _import {
my $self = shift;
my ($struct) = @_;
foreach my $key (keys %$struct) {
$self->put($key, $struct->{$key});
}
return 1;
}
sub TIEHASH {
##
# Tied hash constructor method, called by Perl's tie() function.
##
my $class = shift;
my $args = $class->_get_args( @_ );
$args->{type} = $class->TYPE_HASH;
return $class->_init($args);
}
sub FETCH {
my $self = shift->_get_self;
DBM::Deep::10002->_throw_error( "Cannot use an undefined hash key." ) unless defined $_[0];
my $key = ($self->_storage->{filter_store_key})
? $self->_storage->{filter_store_key}->($_[0])
: $_[0];
return $self->SUPER::FETCH( $key, $_[0] );
}
sub STORE {
my $self = shift->_get_self;
DBM::Deep::10002->_throw_error( "Cannot use an undefined hash key." ) unless defined $_[0];
my $key = ($self->_storage->{filter_store_key})
? $self->_storage->{filter_store_key}->($_[0])
: $_[0];
my $value = $_[1];
return $self->SUPER::STORE( $key, $value, $_[0] );
}
sub EXISTS {
my $self = shift->_get_self;
DBM::Deep::10002->_throw_error( "Cannot use an undefined hash key." ) unless defined $_[0];
my $key = ($self->_storage->{filter_store_key})
? $self->_storage->{filter_store_key}->($_[0])
: $_[0];
return $self->SUPER::EXISTS( $key );
}
sub DELETE {
my $self = shift->_get_self;
DBM::Deep::10002->_throw_error( "Cannot use an undefined hash key." ) unless defined $_[0];
my $key = ($self->_storage->{filter_store_key})
? $self->_storage->{filter_store_key}->($_[0])
: $_[0];
return $self->SUPER::DELETE( $key, $_[0] );
}
sub FIRSTKEY {
##
# Locate and return first key (in no particular order)
##
my $self = shift->_get_self;
##
# Request shared lock for reading
##
$self->lock( $self->LOCK_SH );
my $result = $self->_engine->get_next_key( $self );
$self->unlock();
return ($result && $self->_storage->{filter_fetch_key})
? $self->_storage->{filter_fetch_key}->($result)
: $result;
}
sub NEXTKEY {
##
# Return next key (in no particular order), given previous one
##
my $self = shift->_get_self;
my $prev_key = ($self->_storage->{filter_store_key})
? $self->_storage->{filter_store_key}->($_[0])
: $_[0];
##
# Request shared lock for reading
##
$self->lock( $self->LOCK_SH );
my $result = $self->_engine->get_next_key( $self, $prev_key );
$self->unlock();
return ($result && $self->_storage->{filter_fetch_key})
? $self->_storage->{filter_fetch_key}->($result)
: $result;
}
##
# Public method aliases
##
sub first_key { (shift)->FIRSTKEY(@_) }
sub next_key { (shift)->NEXTKEY(@_) }
sub _copy_node {
my $self = shift;
my ($db_temp) = @_;
my $key = $self->first_key();
while ($key) {
my $value = $self->get($key);
$self->_copy_value( \$db_temp->{$key}, $value );
$key = $self->next_key($key);
}
return 1;
}
package DBM::Deep::10002::File;
use 5.006_000;
use strict;
use warnings;
our $VERSION = q(1.0002);
use Fcntl qw( :DEFAULT :flock :seek );
sub new {
my $class = shift;
my ($args) = @_;
my $self = bless {
autobless => 1,
autoflush => 1,
end => 0,
fh => undef,
file => undef,
file_offset => 0,
locking => 1,
locked => 0,
#XXX Migrate this to the engine, where it really belongs.
filter_store_key => undef,
filter_store_value => undef,
filter_fetch_key => undef,
filter_fetch_value => undef,
}, $class;
# Grab the parameters we want to use
foreach my $param ( keys %$self ) {
next unless exists $args->{$param};
$self->{$param} = $args->{$param};
}
if ( $self->{fh} && !$self->{file_offset} ) {
$self->{file_offset} = tell( $self->{fh} );
}
$self->open unless $self->{fh};
return $self;
}
sub open {
my $self = shift;
# Adding O_BINARY should remove the need for the binmode below. However,
# I'm not going to remove it because I don't have the Win32 chops to be
# absolutely certain everything will be ok.
my $flags = O_CREAT | O_BINARY;
if ( !-e $self->{file} || -w _ ) {
$flags |= O_RDWR;
}
else {
$flags |= O_RDONLY;
}
my $fh;
sysopen( $fh, $self->{file}, $flags )
or die "DBM::Deep::10002: Cannot sysopen file '$self->{file}': $!\n";
$self->{fh} = $fh;
# Even though we use O_BINARY, better be safe than sorry.
binmode $fh;
if ($self->{autoflush}) {
my $old = select $fh;
$|=1;
select $old;
}
return 1;
}
sub close {
my $self = shift;
if ( $self->{fh} ) {
close $self->{fh};
$self->{fh} = undef;
}
return 1;
}
sub set_inode {
my $self = shift;
unless ( defined $self->{inode} ) {
my @stats = stat($self->{fh});
$self->{inode} = $stats[1];
$self->{end} = $stats[7];
}
return 1;
}
sub print_at {
my $self = shift;
my $loc = shift;
local ($/,$\);
my $fh = $self->{fh};
if ( defined $loc ) {
seek( $fh, $loc + $self->{file_offset}, SEEK_SET );
}
print( $fh @_ );
return 1;
}
sub read_at {
my $self = shift;
my ($loc, $size) = @_;
local ($/,$\);
my $fh = $self->{fh};
if ( defined $loc ) {
seek( $fh, $loc + $self->{file_offset}, SEEK_SET );
}
my $buffer;
read( $fh, $buffer, $size);
return $buffer;
}
sub DESTROY {
my $self = shift;
return unless $self;
$self->close;
return;
}
sub request_space {
my $self = shift;
my ($size) = @_;
#XXX Do I need to reset $self->{end} here? I need a testcase
my $loc = $self->{end};
$self->{end} += $size;
return $loc;
}
##
# If db locking is set, flock() the db file. If called multiple
# times before unlock(), then the same number of unlocks() must
# be called before the lock is released.
##
sub lock {
my $self = shift;
my ($obj, $type) = @_;
$type = LOCK_EX unless defined $type;
if (!defined($self->{fh})) { return; }
if ($self->{locking}) {
if (!$self->{locked}) {
flock($self->{fh}, $type);
# refresh end counter in case file has changed size
my @stats = stat($self->{fh});
$self->{end} = $stats[7];
# double-check file inode, in case another process
# has optimize()d our file while we were waiting.
if (defined($self->{inode}) && $stats[1] != $self->{inode}) {
$self->close;
$self->open;
#XXX This needs work
$obj->{engine}->setup_fh( $obj );
flock($self->{fh}, $type); # re-lock
# This may not be necessary after re-opening
$self->{end} = (stat($self->{fh}))[7]; # re-end
}
}
$self->{locked}++;
return 1;
}
return;
}
##
# If db locking is set, unlock the db file. See note in lock()
# regarding calling lock() multiple times.
##
sub unlock {
my $self = shift;
if (!defined($self->{fh})) { return; }
if ($self->{locking} && $self->{locked} > 0) {
$self->{locked}--;
if (!$self->{locked}) { flock($self->{fh}, LOCK_UN); }
return 1;
}
return;
}
sub flush {
my $self = shift;
# Flush the filehandle
my $old_fh = select $self->{fh};
my $old_af = $|; $| = 1; $| = $old_af;
select $old_fh;
return 1;
}
package DBM::Deep::10002::Engine;
use 5.006_000;
use strict;
use warnings;
our $VERSION = q(1.0002);
use Scalar::Util ();
# File-wide notes:
# * Every method in here assumes that the storage has been appropriately
# safeguarded. This can be anything from flock() to some sort of manual
# mutex. But, it's the caller's responsability to make sure that this has
# been done.
# Setup file and tag signatures. These should never change.
sub SIG_FILE () { 'DPDB' }
sub SIG_HEADER () { 'h' }
sub SIG_HASH () { 'H' }
sub SIG_ARRAY () { 'A' }
sub SIG_NULL () { 'N' }
sub SIG_DATA () { 'D' }
sub SIG_INDEX () { 'I' }
sub SIG_BLIST () { 'B' }
sub SIG_FREE () { 'F' }
sub SIG_SIZE () { 1 }
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 new {
my $class = shift;
my ($args) = @_;
my $self = bless {
byte_size => 4,
digest => undef,
hash_size => 16, # In bytes
hash_chars => 256, # Number of chars the algorithm uses per byte
max_buckets => 16,
num_txns => 1, # The HEAD
trans_id => 0, # Default to the HEAD
data_sector_size => 64, # Size in bytes of each data sector
entries => {}, # This is the list of entries for transactions
storage => undef,
}, $class;
# Never allow byte_size to be set directly.
delete $args->{byte_size};
if ( defined $args->{pack_size} ) {
if ( lc $args->{pack_size} eq 'small' ) {
$args->{byte_size} = 2;
}
elsif ( lc $args->{pack_size} eq 'medium' ) {
$args->{byte_size} = 4;
}
elsif ( lc $args->{pack_size} eq 'large' ) {
$args->{byte_size} = 8;
}
else {
DBM::Deep::10002->_throw_error( "Unknown pack_size value: '$args->{pack_size}'" );
}
}
# Grab the parameters we want to use
foreach my $param ( keys %$self ) {
next unless exists $args->{$param};
$self->{$param} = $args->{$param};
}
my %validations = (
max_buckets => { floor => 16, ceil => 256 },
num_txns => { floor => 1, ceil => 255 },
data_sector_size => { floor => 32, ceil => 256 },
);
while ( my ($attr, $c) = each %validations ) {
if ( !defined $self->{$attr}
|| !length $self->{$attr}
|| $self->{$attr} =~ /\D/
|| $self->{$attr} < $c->{floor}
) {
$self->{$attr} = '(undef)' if !defined $self->{$attr};
warn "Floor of $attr is $c->{floor}. Setting it to $c->{floor} from '$self->{$attr}'\n";
$self->{$attr} = $c->{floor};
}
elsif ( $self->{$attr} > $c->{ceil} ) {
warn "Ceiling of $attr is $c->{ceil}. Setting it to $c->{ceil} from '$self->{$attr}'\n";
$self->{$attr} = $c->{ceil};
}
}
if ( !$self->{digest} ) {
require Digest::MD5;
$self->{digest} = \&Digest::MD5::md5;
}
return $self;
}
################################################################################
sub read_value {
my $self = shift;
my ($obj, $key) = @_;
# This will be a Reference sector
my $sector = $self->_load_sector( $obj->_base_offset )
or return;
if ( $sector->staleness != $obj->_staleness ) {
return;
}
my $key_md5 = $self->_apply_digest( $key );
my $value_sector = $sector->get_data_for({
key_md5 => $key_md5,
allow_head => 1,
});
unless ( $value_sector ) {
$value_sector = DBM::Deep::10002::Engine::Sector::Null->new({
engine => $self,
data => undef,
});
$sector->write_data({
key_md5 => $key_md5,
key => $key,
value => $value_sector,
});
}
return $value_sector->data;
}
sub get_classname {
my $self = shift;
my ($obj) = @_;
# This will be a Reference sector
my $sector = $self->_load_sector( $obj->_base_offset )
or DBM::Deep::10002->_throw_error( "How did get_classname fail (no sector for '$obj')?!" );
if ( $sector->staleness != $obj->_staleness ) {
return;
}
return $sector->get_classname;
}
sub key_exists {
my $self = shift;
my ($obj, $key) = @_;
# This will be a Reference sector
my $sector = $self->_load_sector( $obj->_base_offset )
or return '';
if ( $sector->staleness != $obj->_staleness ) {
return '';
}
my $data = $sector->get_data_for({
key_md5 => $self->_apply_digest( $key ),
allow_head => 1,
});
# exists() returns 1 or '' for true/false.
return $data ? 1 : '';
}
sub delete_key {
my $self = shift;
my ($obj, $key) = @_;
my $sector = $self->_load_sector( $obj->_base_offset )
or return;
if ( $sector->staleness != $obj->_staleness ) {
return;
}
return $sector->delete_key({
key_md5 => $self->_apply_digest( $key ),
allow_head => 0,
});
}
sub write_value {
my $self = shift;
my ($obj, $key, $value) = @_;
my $r = Scalar::Util::reftype( $value ) || '';
{
last if $r eq '';
last if $r eq 'HASH';
last if $r eq 'ARRAY';
DBM::Deep::10002->_throw_error(
"Storage of references of type '$r' is not supported."
);
}
my ($class, $type);
if ( !defined $value ) {
$class = 'DBM::Deep::10002::Engine::Sector::Null';
}
elsif ( $r eq 'ARRAY' || $r eq 'HASH' ) {
if ( $r eq 'ARRAY' && tied(@$value) ) {
DBM::Deep::10002->_throw_error( "Cannot store something that is tied." );
}
if ( $r eq 'HASH' && tied(%$value) ) {
DBM::Deep::10002->_throw_error( "Cannot store something that is tied." );
}
$class = 'DBM::Deep::10002::Engine::Sector::Reference';
$type = substr( $r, 0, 1 );
}
else {
$class = 'DBM::Deep::10002::Engine::Sector::Scalar';
}
# This will be a Reference sector
my $sector = $self->_load_sector( $obj->_base_offset )
or DBM::Deep::10002->_throw_error( "Cannot write to a deleted spot in DBM::Deep::10002." );
if ( $sector->staleness != $obj->_staleness ) {
DBM::Deep::10002->_throw_error( "Cannot write to a deleted spot in DBM::Deep::10002.n" );
}
# Create this after loading the reference sector in case something bad happens.
# This way, we won't allocate value sector(s) needlessly.
my $value_sector = $class->new({
engine => $self,
data => $value,
type => $type,
});
$sector->write_data({
key => $key,
key_md5 => $self->_apply_digest( $key ),
value => $value_sector,
});
# This code is to make sure we write all the values in the $value to the disk
# and to make sure all changes to $value after the assignment are reflected
# on disk. This may be counter-intuitive at first, but it is correct dwimmery.
# NOTE - simply tying $value won't perform a STORE on each value. Hence, the
# copy to a temp value.
if ( $r eq 'ARRAY' ) {
my @temp = @$value;
tie @$value, 'DBM::Deep::10002', {
base_offset => $value_sector->offset,
staleness => $value_sector->staleness,
storage => $self->storage,
engine => $self,
};
@$value = @temp;
bless $value, 'DBM::Deep::10002::Array' unless Scalar::Util::blessed( $value );
}
elsif ( $r eq 'HASH' ) {
my %temp = %$value;
tie %$value, 'DBM::Deep::10002', {
base_offset => $value_sector->offset,
staleness => $value_sector->staleness,
storage => $self->storage,
engine => $self,
};
%$value = %temp;
bless $value, 'DBM::Deep::10002::Hash' unless Scalar::Util::blessed( $value );
}
return 1;
}
# XXX Add staleness here
sub get_next_key {
my $self = shift;
my ($obj, $prev_key) = @_;
# XXX Need to add logic about resetting the iterator if any key in the reference has changed
unless ( $prev_key ) {
$obj->{iterator} = DBM::Deep::10002::Iterator->new({
base_offset => $obj->_base_offset,
engine => $self,
});
}
return $obj->{iterator}->get_next_key( $obj );
}
################################################################################
sub setup_fh {
my $self = shift;
my ($obj) = @_;
# We're opening the file.
unless ( $obj->_base_offset ) {
my $bytes_read = $self->_read_file_header;
# Creating a new file
unless ( $bytes_read ) {
$self->_write_file_header;
# 1) Create Array/Hash entry
my $initial_reference = DBM::Deep::10002::Engine::Sector::Reference->new({
engine => $self,
type => $obj->_type,
});
$obj->{base_offset} = $initial_reference->offset;
$obj->{staleness} = $initial_reference->staleness;
$self->storage->flush;
}
# Reading from an existing file
else {
$obj->{base_offset} = $bytes_read;
my $initial_reference = DBM::Deep::10002::Engine::Sector::Reference->new({
engine => $self,
offset => $obj->_base_offset,
});
unless ( $initial_reference ) {
DBM::Deep::10002->_throw_error("Corrupted file, no master index record");
}
unless ($obj->_type eq $initial_reference->type) {
DBM::Deep::10002->_throw_error("File type mismatch");
}
$obj->{staleness} = $initial_reference->staleness;
}
}
return 1;
}
sub begin_work {
my $self = shift;
my ($obj) = @_;
if ( $self->trans_id ) {
DBM::Deep::10002->_throw_error( "Cannot begin_work within an active transaction" );
}
my @slots = $self->read_txn_slots;
my $found;
for my $i ( 0 .. $#slots ) {
next if $slots[$i];
$slots[$i] = 1;
$self->set_trans_id( $i + 1 );
$found = 1;
last;
}
unless ( $found ) {
DBM::Deep::10002->_throw_error( "Cannot allocate transaction ID" );
}
$self->write_txn_slots( @slots );
if ( !$self->trans_id ) {
DBM::Deep::10002->_throw_error( "Cannot begin_work - no available transactions" );
}
return;
}
sub rollback {
my $self = shift;
my ($obj) = @_;
if ( !$self->trans_id ) {
DBM::Deep::10002->_throw_error( "Cannot rollback without an active transaction" );
}
# Each entry is the file location for a bucket that has a modification for
# this transaction. The entries need to be expunged.
foreach my $entry (@{ $self->get_entries } ) {
# Remove the entry here
my $read_loc = $entry
+ $self->hash_size
+ $self->byte_size
+ $self->byte_size
+ ($self->trans_id - 1) * ( $self->byte_size + $STALE_SIZE );
my $data_loc = $self->storage->read_at( $read_loc, $self->byte_size );
$data_loc = unpack( $StP{$self->byte_size}, $data_loc );
$self->storage->print_at( $read_loc, pack( $StP{$self->byte_size}, 0 ) );
if ( $data_loc > 1 ) {
$self->_load_sector( $data_loc )->free;
}
}
$self->clear_entries;
my @slots = $self->read_txn_slots;
$slots[$self->trans_id-1] = 0;
$self->write_txn_slots( @slots );
$self->inc_txn_staleness_counter( $self->trans_id );
$self->set_trans_id( 0 );
return 1;
}
sub commit {
my $self = shift;
my ($obj) = @_;
if ( !$self->trans_id ) {
DBM::Deep::10002->_throw_error( "Cannot commit without an active transaction" );
}
foreach my $entry (@{ $self->get_entries } ) {
# Overwrite the entry in head with the entry in trans_id
my $base = $entry
+ $self->hash_size
+ $self->byte_size;
my $head_loc = $self->storage->read_at( $base, $self->byte_size );
$head_loc = unpack( $StP{$self->byte_size}, $head_loc );
my $spot = $base + $self->byte_size + ($self->trans_id - 1) * ( $self->byte_size + $STALE_SIZE );
my $trans_loc = $self->storage->read_at(
$spot, $self->byte_size,
);
$self->storage->print_at( $base, $trans_loc );
$self->storage->print_at(
$spot,
pack( $StP{$self->byte_size} . ' ' . $StP{$STALE_SIZE}, (0) x 2 ),
);
if ( $head_loc > 1 ) {
$self->_load_sector( $head_loc )->free;
}
}
$self->clear_entries;
my @slots = $self->read_txn_slots;
$slots[$self->trans_id-1] = 0;
$self->write_txn_slots( @slots );
$self->inc_txn_staleness_counter( $self->trans_id );
$self->set_trans_id( 0 );
return 1;
}
sub read_txn_slots {
my $self = shift;
my $bl = $self->txn_bitfield_len;
my $num_bits = $bl * 8;
return split '', unpack( 'b'.$num_bits,
$self->storage->read_at(
$self->trans_loc, $bl,
)
);
}
sub write_txn_slots {
my $self = shift;
my $num_bits = $self->txn_bitfield_len * 8;
$self->storage->print_at( $self->trans_loc,
pack( 'b'.$num_bits, join('', @_) ),
);
}
sub get_running_txn_ids {
my $self = shift;
my @transactions = $self->read_txn_slots;
my @trans_ids = map { $_+1} grep { $transactions[$_] } 0 .. $#transactions;
}
sub get_txn_staleness_counter {
my $self = shift;
my ($trans_id) = @_;
# Hardcode staleness of 0 for the HEAD
return 0 unless $trans_id;
return unpack( $StP{$STALE_SIZE},
$self->storage->read_at(
$self->trans_loc + 4 + $STALE_SIZE * ($trans_id - 1),
4,
)
);
}
sub inc_txn_staleness_counter {
my $self = shift;
my ($trans_id) = @_;
# Hardcode staleness of 0 for the HEAD
return unless $trans_id;
$self->storage->print_at(
$self->trans_loc + 4 + $STALE_SIZE * ($trans_id - 1),
pack( $StP{$STALE_SIZE}, $self->get_txn_staleness_counter( $trans_id ) + 1 ),
);
}
sub get_entries {
my $self = shift;
return [ keys %{ $self->{entries}{$self->trans_id} ||= {} } ];
}
sub add_entry {
my $self = shift;
my ($trans_id, $loc) = @_;
$self->{entries}{$trans_id} ||= {};
$self->{entries}{$trans_id}{$loc} = undef;
}
# If the buckets are being relocated because of a reindexing, the entries
# mechanism needs to be made aware of it.
sub reindex_entry {
my $self = shift;
my ($old_loc, $new_loc) = @_;
TRANS:
while ( my ($trans_id, $locs) = each %{ $self->{entries} } ) {
foreach my $orig_loc ( keys %{ $locs } ) {
if ( $orig_loc == $old_loc ) {
delete $locs->{orig_loc};
$locs->{$new_loc} = undef;
next TRANS;
}
}
}
}
sub clear_entries {
my $self = shift;
delete $self->{entries}{$self->trans_id};
}
################################################################################
{
my $header_fixed = length( SIG_FILE ) + 1 + 4 + 4;
my $this_file_version = 2;
sub _write_file_header {
my $self = shift;
my $nt = $self->num_txns;
my $bl = $self->txn_bitfield_len;
my $header_var = 1 + 1 + 1 + 1 + $bl + $STALE_SIZE * ($nt - 1) + 3 * $self->byte_size;
my $loc = $self->storage->request_space( $header_fixed + $header_var );
$self->storage->print_at( $loc,
SIG_FILE,
SIG_HEADER,
pack('N', $this_file_version), # At this point, we're at 9 bytes
pack('N', $header_var), # header size
# --- Above is $header_fixed. Below is $header_var
pack('C', $self->byte_size),
# These shenanigans are to allow a 256 within a C
pack('C', $self->max_buckets - 1),
pack('C', $self->data_sector_size - 1),
pack('C', $nt),
pack('C' . $bl, 0 ), # Transaction activeness bitfield
pack($StP{$STALE_SIZE}.($nt-1), 0 x ($nt-1) ), # Transaction staleness counters
pack($StP{$self->byte_size}, 0), # Start of free chain (blist size)
pack($StP{$self->byte_size}, 0), # Start of free chain (data size)
pack($StP{$self->byte_size}, 0), # Start of free chain (index size)
);
#XXX Set these less fragilely
$self->set_trans_loc( $header_fixed + 4 );
$self->set_chains_loc( $header_fixed + 4 + $bl + $STALE_SIZE * ($nt-1) );
return;
}
sub _read_file_header {
my $self = shift;
my $buffer = $self->storage->read_at( 0, $header_fixed );
return unless length($buffer);
my ($file_signature, $sig_header, $file_version, $size) = unpack(
'A4 A N N', $buffer
);
unless ( $file_signature eq SIG_FILE ) {
$self->storage->close;
DBM::Deep::10002->_throw_error( "Signature not found -- file is not a Deep DB" );
}
unless ( $sig_header eq SIG_HEADER ) {
$self->storage->close;
DBM::Deep::10002->_throw_error( "Pre-1.00 file version found" );
}
unless ( $file_version == $this_file_version ) {
$self->storage->close;
DBM::Deep::10002->_throw_error(
"Wrong file version found - " . $file_version .
" - expected " . $this_file_version
);
}
my $buffer2 = $self->storage->read_at( undef, $size );
my @values = unpack( 'C C C C', $buffer2 );
if ( @values != 4 || grep { !defined } @values ) {
$self->storage->close;
DBM::Deep::10002->_throw_error("Corrupted file - bad header");
}
#XXX Add warnings if values weren't set right
@{$self}{qw(byte_size max_buckets data_sector_size num_txns)} = @values;
# These shenangians are to allow a 256 within a C
$self->{max_buckets} += 1;
$self->{data_sector_size} += 1;
my $bl = $self->txn_bitfield_len;
my $header_var = scalar(@values) + $bl + $STALE_SIZE * ($self->num_txns - 1) + 3 * $self->byte_size;
unless ( $size == $header_var ) {
$self->storage->close;
DBM::Deep::10002->_throw_error( "Unexpected size found ($size <-> $header_var)." );
}
$self->set_trans_loc( $header_fixed + scalar(@values) );
$self->set_chains_loc( $header_fixed + scalar(@values) + $bl + $STALE_SIZE * ($self->num_txns - 1) );
return length($buffer) + length($buffer2);
}
}
sub _load_sector {
my $self = shift;
my ($offset) = @_;
# Add a catch for offset of 0 or 1
return if $offset <= 1;
my $type = $self->storage->read_at( $offset, 1 );
return if $type eq chr(0);
if ( $type eq $self->SIG_ARRAY || $type eq $self->SIG_HASH ) {
return DBM::Deep::10002::Engine::Sector::Reference->new({
engine => $self,
type => $type,
offset => $offset,
});
}
# XXX Don't we need key_md5 here?
elsif ( $type eq $self->SIG_BLIST ) {
return DBM::Deep::10002::Engine::Sector::BucketList->new({
engine => $self,
type => $type,
offset => $offset,
});
}
elsif ( $type eq $self->SIG_INDEX ) {
return DBM::Deep::10002::Engine::Sector::Index->new({
engine => $self,
type => $type,
offset => $offset,
});
}
elsif ( $type eq $self->SIG_NULL ) {
return DBM::Deep::10002::Engine::Sector::Null->new({
engine => $self,
type => $type,
offset => $offset,
});
}
elsif ( $type eq $self->SIG_DATA ) {
return DBM::Deep::10002::Engine::Sector::Scalar->new({
engine => $self,
type => $type,
offset => $offset,
});
}
# This was deleted from under us, so just return and let the caller figure it out.
elsif ( $type eq $self->SIG_FREE ) {
return;
}
DBM::Deep::10002->_throw_error( "'$offset': Don't know what to do with type '$type'" );
}
sub _apply_digest {
my $self = shift;
return $self->{digest}->(@_);
}
sub _add_free_blist_sector { shift->_add_free_sector( 0, @_ ) }
sub _add_free_data_sector { shift->_add_free_sector( 1, @_ ) }
sub _add_free_index_sector { shift->_add_free_sector( 2, @_ ) }
sub _add_free_sector {
my $self = shift;
my ($multiple, $offset, $size) = @_;
my $chains_offset = $multiple * $self->byte_size;
my $storage = $self->storage;
# Increment staleness.
# XXX Can this increment+modulo be done by "&= 0x1" ?
my $staleness = unpack( $StP{$STALE_SIZE}, $storage->read_at( $offset + SIG_SIZE, $STALE_SIZE ) );
$staleness = ($staleness + 1 ) % ( 2 ** ( 8 * $STALE_SIZE ) );
$storage->print_at( $offset + SIG_SIZE, pack( $StP{$STALE_SIZE}, $staleness ) );
my $old_head = $storage->read_at( $self->chains_loc + $chains_offset, $self->byte_size );
$storage->print_at( $self->chains_loc + $chains_offset,
pack( $StP{$self->byte_size}, $offset ),
);
# Record the old head in the new sector after the signature and staleness counter
$storage->print_at( $offset + SIG_SIZE + $STALE_SIZE, $old_head );
}
sub _request_blist_sector { shift->_request_sector( 0, @_ ) }
sub _request_data_sector { shift->_request_sector( 1, @_ ) }
sub _request_index_sector { shift->_request_sector( 2, @_ ) }
sub _request_sector {
my $self = shift;
my ($multiple, $size) = @_;
my $chains_offset = $multiple * $self->byte_size;
my $old_head = $self->storage->read_at( $self->chains_loc + $chains_offset, $self->byte_size );
my $loc = unpack( $StP{$self->byte_size}, $old_head );
# We don't have any free sectors of the right size, so allocate a new one.
unless ( $loc ) {
my $offset = $self->storage->request_space( $size );
# Zero out the new sector. This also guarantees correct increases
# in the filesize.
$self->storage->print_at( $offset, chr(0) x $size );
return $offset;
}
# Read the new head after the signature and the staleness counter
my $new_head = $self->storage->read_at( $loc + SIG_SIZE + $STALE_SIZE, $self->byte_size );
$self->storage->print_at( $self->chains_loc + $chains_offset, $new_head );
$self->storage->print_at(
$loc + SIG_SIZE + $STALE_SIZE,
pack( $StP{$self->byte_size}, 0 ),
);
return $loc;
}
################################################################################
sub storage { $_[0]{storage} }
sub byte_size { $_[0]{byte_size} }
sub hash_size { $_[0]{hash_size} }
sub hash_chars { $_[0]{hash_chars} }
sub num_txns { $_[0]{num_txns} }
sub max_buckets { $_[0]{max_buckets} }
sub blank_md5 { chr(0) x $_[0]->hash_size }
sub data_sector_size { $_[0]{data_sector_size} }
# This is a calculated value
sub txn_bitfield_len {
my $self = shift;
unless ( exists $self->{txn_bitfield_len} ) {
my $temp = ($self->num_txns) / 8;
if ( $temp > int( $temp ) ) {
$temp = int( $temp ) + 1;
}
$self->{txn_bitfield_len} = $temp;
}
return $self->{txn_bitfield_len};
}
sub trans_id { $_[0]{trans_id} }
sub set_trans_id { $_[0]{trans_id} = $_[1] }
sub trans_loc { $_[0]{trans_loc} }
sub set_trans_loc { $_[0]{trans_loc} = $_[1] }
sub chains_loc { $_[0]{chains_loc} }
sub set_chains_loc { $_[0]{chains_loc} = $_[1] }
################################################################################
package DBM::Deep::10002::Iterator;
sub new {
my $class = shift;
my ($args) = @_;
my $self = bless {
breadcrumbs => [],
engine => $args->{engine},
base_offset => $args->{base_offset},
}, $class;
Scalar::Util::weaken( $self->{engine} );
return $self;
}
sub reset { $_[0]{breadcrumbs} = [] }
sub get_sector_iterator {
my $self = shift;
my ($loc) = @_;
my $sector = $self->{engine}->_load_sector( $loc )
or return;
if ( $sector->isa( 'DBM::Deep::10002::Engine::Sector::Index' ) ) {
return DBM::Deep::10002::Iterator::Index->new({
iterator => $self,
sector => $sector,
});
}
elsif ( $sector->isa( 'DBM::Deep::10002::Engine::Sector::BucketList' ) ) {
return DBM::Deep::10002::Iterator::BucketList->new({
iterator => $self,
sector => $sector,
});
}
DBM::Deep::10002->_throw_error( "get_sector_iterator(): Why did $loc make a $sector?" );
}
sub get_next_key {
my $self = shift;
my ($obj) = @_;
my $crumbs = $self->{breadcrumbs};
my $e = $self->{engine};
unless ( @$crumbs ) {
# This will be a Reference sector
my $sector = $e->_load_sector( $self->{base_offset} )
# If no sector is found, thist must have been deleted from under us.
or return;
if ( $sector->staleness != $obj->_staleness ) {
return;
}
my $loc = $sector->get_blist_loc
or return;
push @$crumbs, $self->get_sector_iterator( $loc );
}
FIND_NEXT_KEY: {
# We're at the end.
unless ( @$crumbs ) {
$self->reset;
return;
}
my $iterator = $crumbs->[-1];
# This level is done.
if ( $iterator->at_end ) {
pop @$crumbs;
redo FIND_NEXT_KEY;
}
if ( $iterator->isa( 'DBM::Deep::10002::Iterator::Index' ) ) {
# If we don't have any more, it will be caught at the
# prior check.
if ( my $next = $iterator->get_next_iterator ) {
push @$crumbs, $next;
}
redo FIND_NEXT_KEY;
}
unless ( $iterator->isa( 'DBM::Deep::10002::Iterator::BucketList' ) ) {
DBM::Deep::10002->_throw_error(
"Should have a bucketlist iterator here - instead have $iterator"
);
}
# At this point, we have a BucketList iterator
my $key = $iterator->get_next_key;
if ( defined $key ) {
return $key;
}
#XXX else { $iterator->set_to_end() } ?
# We hit the end of the bucketlist iterator, so redo
redo FIND_NEXT_KEY;
}
DBM::Deep::10002->_throw_error( "get_next_key(): How did we get here?" );
}
package DBM::Deep::10002::Iterator::Index;
sub new {
my $self = bless $_[1] => $_[0];
$self->{curr_index} = 0;
return $self;
}
sub at_end {
my $self = shift;
return $self->{curr_index} >= $self->{iterator}{engine}->hash_chars;
}
sub get_next_iterator {
my $self = shift;
my $loc;
while ( !$loc ) {
return if $self->at_end;
$loc = $self->{sector}->get_entry( $self->{curr_index}++ );
}
return $self->{iterator}->get_sector_iterator( $loc );
}
package DBM::Deep::10002::Iterator::BucketList;
sub new {
my $self = bless $_[1] => $_[0];
$self->{curr_index} = 0;
return $self;
}
sub at_end {
my $self = shift;
return $self->{curr_index} >= $self->{iterator}{engine}->max_buckets;
}
sub get_next_key {
my $self = shift;
return if $self->at_end;
my $idx = $self->{curr_index}++;
my $data_loc = $self->{sector}->get_data_location_for({
allow_head => 1,
idx => $idx,
}) or return;
#XXX Do we want to add corruption checks here?
return $self->{sector}->get_key_for( $idx )->data;
}
package DBM::Deep::10002::Engine::Sector;
sub new {
my $self = bless $_[1], $_[0];
Scalar::Util::weaken( $self->{engine} );
$self->_init;
return $self;
}
#sub _init {}
#sub clone { DBM::Deep::10002->_throw_error( "Must be implemented in the child class" ); }
sub engine { $_[0]{engine} }
sub offset { $_[0]{offset} }
sub type { $_[0]{type} }
sub base_size {
my $self = shift;
return $self->engine->SIG_SIZE + $STALE_SIZE;
}
sub free {
my $self = shift;
my $e = $self->engine;
$e->storage->print_at( $self->offset, $e->SIG_FREE );
# Skip staleness counter
$e->storage->print_at( $self->offset + $self->base_size,
chr(0) x ($self->size - $self->base_size),
);
my $free_meth = $self->free_meth;
$e->$free_meth( $self->offset, $self->size );
return;
}
package DBM::Deep::10002::Engine::Sector::Data;
our @ISA = qw( DBM::Deep::10002::Engine::Sector );
# This is in bytes
sub size { $_[0]{engine}->data_sector_size }
sub free_meth { return '_add_free_data_sector' }
sub clone {
my $self = shift;
return ref($self)->new({
engine => $self->engine,
type => $self->type,
data => $self->data,
});
}
package DBM::Deep::10002::Engine::Sector::Scalar;
our @ISA = qw( DBM::Deep::10002::Engine::Sector::Data );
sub free {
my $self = shift;
my $chain_loc = $self->chain_loc;
$self->SUPER::free();
if ( $chain_loc ) {
$self->engine->_load_sector( $chain_loc )->free;
}
return;
}
sub type { $_[0]{engine}->SIG_DATA }
sub _init {
my $self = shift;
my $engine = $self->engine;
unless ( $self->offset ) {
my $data_section = $self->size - $self->base_size - $engine->byte_size - 1;
$self->{offset} = $engine->_request_data_sector( $self->size );
my $data = delete $self->{data};
my $dlen = length $data;
my $continue = 1;
my $curr_offset = $self->offset;
while ( $continue ) {
my $next_offset = 0;
my ($leftover, $this_len, $chunk);
if ( $dlen > $data_section ) {
$leftover = 0;
$this_len = $data_section;
$chunk = substr( $data, 0, $this_len );
$dlen -= $data_section;
$next_offset = $engine->_request_data_sector( $self->size );
$data = substr( $data, $this_len );
}
else {
$leftover = $data_section - $dlen;
$this_len = $dlen;
$chunk = $data;
$continue = 0;
}
$engine->storage->print_at( $curr_offset, $self->type ); # Sector type
# Skip staleness
$engine->storage->print_at( $curr_offset + $self->base_size,
pack( $StP{$engine->byte_size}, $next_offset ), # Chain loc
pack( $StP{1}, $this_len ), # Data length
$chunk, # Data to be stored in this sector
chr(0) x $leftover, # Zero-fill the rest
);
$curr_offset = $next_offset;
}
return;
}
}
sub data_length {
my $self = shift;
my $buffer = $self->engine->storage->read_at(
$self->offset + $self->base_size + $self->engine->byte_size, 1
);
return unpack( $StP{1}, $buffer );
}
sub chain_loc {
my $self = shift;
return unpack(
$StP{$self->engine->byte_size},
$self->engine->storage->read_at(
$self->offset + $self->base_size,
$self->engine->byte_size,
),
);
}
sub data {
my $self = shift;
my $data;
while ( 1 ) {
my $chain_loc = $self->chain_loc;
$data .= $self->engine->storage->read_at(
$self->offset + $self->base_size + $self->engine->byte_size + 1, $self->data_length,
);
last unless $chain_loc;
$self = $self->engine->_load_sector( $chain_loc );
}
return $data;
}
package DBM::Deep::10002::Engine::Sector::Null;
our @ISA = qw( DBM::Deep::10002::Engine::Sector::Data );
sub type { $_[0]{engine}->SIG_NULL }
sub data_length { 0 }
sub data { return }
sub _init {
my $self = shift;
my $engine = $self->engine;
unless ( $self->offset ) {
my $leftover = $self->size - $self->base_size - 1 * $engine->byte_size - 1;
$self->{offset} = $engine->_request_data_sector( $self->size );
$engine->storage->print_at( $self->offset, $self->type ); # Sector type
# Skip staleness counter
$engine->storage->print_at( $self->offset + $self->base_size,
pack( $StP{$engine->byte_size}, 0 ), # Chain loc
pack( $StP{1}, $self->data_length ), # Data length
chr(0) x $leftover, # Zero-fill the rest
);
return;
}
}
package DBM::Deep::10002::Engine::Sector::Reference;
our @ISA = qw( DBM::Deep::10002::Engine::Sector::Data );
sub _init {
my $self = shift;
my $e = $self->engine;
unless ( $self->offset ) {
my $classname = Scalar::Util::blessed( delete $self->{data} );
my $leftover = $self->size - $self->base_size - 2 * $e->byte_size;
my $class_offset = 0;
if ( defined $classname ) {
my $class_sector = DBM::Deep::10002::Engine::Sector::Scalar->new({
engine => $e,
data => $classname,
});
$class_offset = $class_sector->offset;
}
$self->{offset} = $e->_request_data_sector( $self->size );
$e->storage->print_at( $self->offset, $self->type ); # Sector type
# Skip staleness counter
$e->storage->print_at( $self->offset + $self->base_size,
pack( $StP{$e->byte_size}, 0 ), # Index/BList loc
pack( $StP{$e->byte_size}, $class_offset ), # Classname loc
chr(0) x $leftover, # Zero-fill the rest
);
}
else {
$self->{type} = $e->storage->read_at( $self->offset, 1 );
}
$self->{staleness} = unpack(
$StP{$STALE_SIZE},
$e->storage->read_at( $self->offset + $e->SIG_SIZE, $STALE_SIZE ),
);
return;
}
sub free {
my $self = shift;
my $blist_loc = $self->get_blist_loc;
$self->engine->_load_sector( $blist_loc )->free if $blist_loc;
my $class_loc = $self->get_class_offset;
$self->engine->_load_sector( $class_loc )->free if $class_loc;
$self->SUPER::free();
}
sub staleness { $_[0]{staleness} }
sub get_data_for {
my $self = shift;
my ($args) = @_;
# Assume that the head is not allowed unless otherwise specified.
$args->{allow_head} = 0 unless exists $args->{allow_head};
# Assume we don't create a new blist location unless otherwise specified.
$args->{create} = 0 unless exists $args->{create};
my $blist = $self->get_bucket_list({
key_md5 => $args->{key_md5},
key => $args->{key},
create => $args->{create},
});
return unless $blist && $blist->{found};
# At this point, $blist knows where the md5 is. What it -doesn't- know yet
# is whether or not this transaction has this key. That's part of the next
# function call.
my $location = $blist->get_data_location_for({
allow_head => $args->{allow_head},
}) or return;
return $self->engine->_load_sector( $location );
}
sub write_data {
my $self = shift;
my ($args) = @_;
my $blist = $self->get_bucket_list({
key_md5 => $args->{key_md5},
key => $args->{key},
create => 1,
}) or DBM::Deep::10002->_throw_error( "How did write_data fail (no blist)?!" );
# Handle any transactional bookkeeping.
if ( $self->engine->trans_id ) {
if ( ! $blist->has_md5 ) {
$blist->mark_deleted({
trans_id => 0,
});
}
}
else {
my @trans_ids = $self->engine->get_running_txn_ids;
if ( $blist->has_md5 ) {
if ( @trans_ids ) {
my $old_value = $blist->get_data_for;
foreach my $other_trans_id ( @trans_ids ) {
next if $blist->get_data_location_for({
trans_id => $other_trans_id,
allow_head => 0,
});
$blist->write_md5({
trans_id => $other_trans_id,
key => $args->{key},
key_md5 => $args->{key_md5},
value => $old_value->clone,
});
}
}
}
else {
if ( @trans_ids ) {
foreach my $other_trans_id ( @trans_ids ) {
#XXX This doesn't seem to possible to ever happen . . .
next if $blist->get_data_location_for({ trans_id => $other_trans_id, allow_head => 0 });
$blist->mark_deleted({
trans_id => $other_trans_id,
});
}
}
}
}
#XXX Is this safe to do transactionally?
# Free the place we're about to write to.
if ( $blist->get_data_location_for({ allow_head => 0 }) ) {
$blist->get_data_for({ allow_head => 0 })->free;
}
$blist->write_md5({
key => $args->{key},
key_md5 => $args->{key_md5},
value => $args->{value},
});
}
sub delete_key {
my $self = shift;
my ($args) = @_;
# XXX What should happen if this fails?
my $blist = $self->get_bucket_list({
key_md5 => $args->{key_md5},
}) or DBM::Deep::10002->_throw_error( "How did delete_key fail (no blist)?!" );
# Save the location so that we can free the data
my $location = $blist->get_data_location_for({
allow_head => 0,
});
my $old_value = $location && $self->engine->_load_sector( $location );
my @trans_ids = $self->engine->get_running_txn_ids;
if ( $self->engine->trans_id == 0 ) {
if ( @trans_ids ) {
foreach my $other_trans_id ( @trans_ids ) {
next if $blist->get_data_location_for({ trans_id => $other_trans_id, allow_head => 0 });
$blist->write_md5({
trans_id => $other_trans_id,
key => $args->{key},
key_md5 => $args->{key_md5},
value => $old_value->clone,
});
}
}
}
my $data;
if ( @trans_ids ) {
$blist->mark_deleted( $args );
if ( $old_value ) {
$data = $old_value->data;
$old_value->free;
}
}
else {
$data = $blist->delete_md5( $args );
}
return $data;
}
sub get_blist_loc {
my $self = shift;
my $e = $self->engine;
my $blist_loc = $e->storage->read_at( $self->offset + $self->base_size, $e->byte_size );
return unpack( $StP{$e->byte_size}, $blist_loc );
}
sub get_bucket_list {
my $self = shift;
my ($args) = @_;
$args ||= {};
# XXX Add in check here for recycling?
my $engine = $self->engine;
my $blist_loc = $self->get_blist_loc;
# There's no index or blist yet
unless ( $blist_loc ) {
return unless $args->{create};
my $blist = DBM::Deep::10002::Engine::Sector::BucketList->new({
engine => $engine,
key_md5 => $args->{key_md5},
});
$engine->storage->print_at( $self->offset + $self->base_size,
pack( $StP{$engine->byte_size}, $blist->offset ),
);
return $blist;
}
my $sector = $engine->_load_sector( $blist_loc )
or DBM::Deep::10002->_throw_error( "Cannot read sector at $blist_loc in get_bucket_list()" );
my $i = 0;
my $last_sector = undef;
while ( $sector->isa( 'DBM::Deep::10002::Engine::Sector::Index' ) ) {
$blist_loc = $sector->get_entry( ord( substr( $args->{key_md5}, $i++, 1 ) ) );
$last_sector = $sector;
if ( $blist_loc ) {
$sector = $engine->_load_sector( $blist_loc )
or DBM::Deep::10002->_throw_error( "Cannot read sector at $blist_loc in get_bucket_list()" );
}
else {
$sector = undef;
last;
}
}
# This means we went through the Index sector(s) and found an empty slot
unless ( $sector ) {
return unless $args->{create};
DBM::Deep::10002->_throw_error( "No last_sector when attempting to build a new entry" )
unless $last_sector;
my $blist = DBM::Deep::10002::Engine::Sector::BucketList->new({
engine => $engine,
key_md5 => $args->{key_md5},
});
$last_sector->set_entry( ord( substr( $args->{key_md5}, $i - 1, 1 ) ) => $blist->offset );
return $blist;
}
$sector->find_md5( $args->{key_md5} );
# See whether or not we need to reindex the bucketlist
if ( !$sector->has_md5 && $args->{create} && $sector->{idx} == -1 ) {
my $new_index = DBM::Deep::10002::Engine::Sector::Index->new({
engine => $engine,
});
my %blist_cache;
#XXX q.v. the comments for this function.
foreach my $entry ( $sector->chopped_up ) {
my ($spot, $md5) = @{$entry};
my $idx = ord( substr( $md5, $i, 1 ) );
# XXX This is inefficient
my $blist = $blist_cache{$idx}
||= DBM::Deep::10002::Engine::Sector::BucketList->new({
engine => $engine,
});
$new_index->set_entry( $idx => $blist->offset );
my $new_spot = $blist->write_at_next_open( $md5 );
$engine->reindex_entry( $spot => $new_spot );
}
# Handle the new item separately.
{
my $idx = ord( substr( $args->{key_md5}, $i, 1 ) );
my $blist = $blist_cache{$idx}
||= DBM::Deep::10002::Engine::Sector::BucketList->new({
engine => $engine,
});
$new_index->set_entry( $idx => $blist->offset );
#XXX THIS IS HACKY!
$blist->find_md5( $args->{key_md5} );
$blist->write_md5({
key => $args->{key},
key_md5 => $args->{key_md5},
value => DBM::Deep::10002::Engine::Sector::Null->new({
engine => $engine,
data => undef,
}),
});
}
if ( $last_sector ) {
$last_sector->set_entry(
ord( substr( $args->{key_md5}, $i - 1, 1 ) ),
$new_index->offset,
);
} else {
$engine->storage->print_at( $self->offset + $self->base_size,
pack( $StP{$engine->byte_size}, $new_index->offset ),
);
}
$sector->free;
$sector = $blist_cache{ ord( substr( $args->{key_md5}, $i, 1 ) ) };
$sector->find_md5( $args->{key_md5} );
}
return $sector;
}
sub get_class_offset {
my $self = shift;
my $e = $self->engine;
return unpack(
$StP{$e->byte_size},
$e->storage->read_at(
$self->offset + $self->base_size + 1 * $e->byte_size, $e->byte_size,
),
);
}
sub get_classname {
my $self = shift;
my $class_offset = $self->get_class_offset;
return unless $class_offset;
return $self->engine->_load_sector( $class_offset )->data;
}
#XXX Add singleton handling here
sub data {
my $self = shift;
my $new_obj = DBM::Deep::10002->new({
type => $self->type,
base_offset => $self->offset,
staleness => $self->staleness,
storage => $self->engine->storage,
engine => $self->engine,
});
if ( $self->engine->storage->{autobless} ) {
my $classname = $self->get_classname;
if ( defined $classname ) {
bless $new_obj, $classname;
}
}
return $new_obj;
}
package DBM::Deep::10002::Engine::Sector::BucketList;
our @ISA = qw( DBM::Deep::10002::Engine::Sector );
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 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 { return '_add_free_blist_sector' }
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::10002->_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::10002->_throw_error( "write_md5: no key" ) unless exists $args->{key};
DBM::Deep::10002->_throw_error( "write_md5: no key_md5" ) unless exists $args->{key_md5};
DBM::Deep::10002->_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::10002::Engine::Sector::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;
$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 );
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::10002->_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::10002->_throw_error( "get_key_for: No location?" ) unless $location;
return $self->engine->_load_sector( $location );
}
package DBM::Deep::10002::Engine::Sector::Index;
our @ISA = qw( DBM::Deep::10002::Engine::Sector );
sub _init {
my $self = shift;
my $engine = $self->engine;
unless ( $self->offset ) {
my $leftover = $self->size - $self->base_size;
$self->{offset} = $engine->_request_index_sector( $self->size );
$engine->storage->print_at( $self->offset, $engine->SIG_INDEX ); # Sector type
# Skip staleness counter
$engine->storage->print_at( $self->offset + $self->base_size,
chr(0) x $leftover, # Zero-fill the rest
);
}
return $self;
}
#XXX Change here
sub size {
my $self = shift;
unless ( $self->{size} ) {
my $e = $self->engine;
$self->{size} = $self->base_size + $e->byte_size * $e->hash_chars;
}
return $self->{size};
}
sub free_meth { return '_add_free_index_sector' }
sub free {
my $self = shift;
my $e = $self->engine;
for my $i ( 0 .. $e->hash_chars - 1 ) {
my $l = $self->get_entry( $i ) or next;
$e->_load_sector( $l )->free;
}
$self->SUPER::free();
}
sub _loc_for {
my $self = shift;
my ($idx) = @_;
return $self->offset + $self->base_size + $idx * $self->engine->byte_size;
}
sub get_entry {
my $self = shift;
my ($idx) = @_;
my $e = $self->engine;
DBM::Deep::10002->_throw_error( "get_entry: Out of range ($idx)" )
if $idx < 0 || $idx >= $e->hash_chars;
return unpack(
$StP{$e->byte_size},
$e->storage->read_at( $self->_loc_for( $idx ), $e->byte_size ),
);
}
sub set_entry {
my $self = shift;
my ($idx, $loc) = @_;
my $e = $self->engine;
DBM::Deep::10002->_throw_error( "set_entry: Out of range ($idx)" )
if $idx < 0 || $idx >= $e->hash_chars;
$self->engine->storage->print_at(
$self->_loc_for( $idx ),
pack( $StP{$e->byte_size}, $loc ),
);
}
1;
__END__