X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBM%2FDeep.pm;h=e08ba84f11615913c092fcc4dd68c916fb65be45;hb=912d50b1c7fab3433aa812baebd75ae7c975ee71;hp=87943170676bc8111a89a3bc75b3762b18b32e4e;hpb=906c8e0107e7c00110cd1a9e6283546091ccae37;p=dbsrgits%2FDBM-Deep.git diff --git a/lib/DBM/Deep.pm b/lib/DBM/Deep.pm index 8794317..e08ba84 100644 --- a/lib/DBM/Deep.pm +++ b/lib/DBM/Deep.pm @@ -24,7 +24,7 @@ package DBM::Deep; # print "This module " . $db->{my_complex}->[1]->{perl} . "!\n"; # # Copyright: -# (c) 2002-2005 Joseph Huckaby. All Rights Reserved. +# (c) 2002-2006 Joseph Huckaby. All Rights Reserved. # This program is free software; you can redistribute it and/or # modify it under the same terms as Perl itself. ## @@ -35,8 +35,10 @@ use Fcntl qw( :DEFAULT :flock :seek ); use Digest::MD5 (); use Scalar::Util (); +use DBM::Deep::Engine; + use vars qw( $VERSION ); -$VERSION = q(0.98); +$VERSION = q(0.99_01); ## # Set to 4 and 'N' for 32-bit offset tags (default). Theoretical limit of 4 GB per file. @@ -62,7 +64,7 @@ our ($LONG_SIZE, $LONG_PACK, $DATA_LENGTH_SIZE, $DATA_LENGTH_PACK); # 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. ## -my $MAX_BUCKETS = 16; +our $MAX_BUCKETS = 16; ## # Better not adjust anything below here, unless you're me :-) @@ -78,7 +80,7 @@ our ($DIGEST_FUNC, $HASH_SIZE); # Precalculate index and bucket sizes based on values above. ## #my $HASH_SIZE = 16; -my ($INDEX_SIZE, $BUCKET_SIZE, $BUCKET_LIST_SIZE); +our ($INDEX_SIZE, $BUCKET_SIZE, $BUCKET_LIST_SIZE); set_digest(); #set_pack(); @@ -163,8 +165,9 @@ sub _init { # These are the defaults to be optionally overridden below my $self = bless { - type => TYPE_HASH, + type => TYPE_HASH, base_offset => length(SIG_FILE), + engine => 'DBM::Deep::Engine', }, $class; foreach my $param ( keys %$self ) { @@ -179,7 +182,7 @@ sub _init { ? $args->{root} : DBM::Deep::_::Root->new( $args ); - if (!defined($self->_fh)) { $self->_open(); } + if (!defined($self->_fh)) { $self->{engine}->open( $self ); } return $self; } @@ -200,595 +203,6 @@ sub TIEARRAY { #sub DESTROY { #} -sub _open { - ## - # Open a fh to the database, create if nonexistent. - # Make sure file signature matches DBM::Deep spec. - ## - my $self = $_[0]->_get_self; - - if (defined($self->_fh)) { $self->_close(); } - - eval { - local $SIG{'__DIE__'}; - # Theoretically, adding O_BINARY should remove the need for the binmode - # Of course, testing it is going to be ... interesting. - my $flags = O_RDWR | O_CREAT | O_BINARY; - - my $fh; - sysopen( $fh, $self->_root->{file}, $flags ) - or $fh = undef; - $self->_root->{fh} = $fh; - }; if ($@ ) { $self->_throw_error( "Received error: $@\n" ); } - if (! defined($self->_fh)) { - return $self->_throw_error("Cannot sysopen file: " . $self->_root->{file} . ": $!"); - } - - my $fh = $self->_fh; - - #XXX Can we remove this by using the right sysopen() flags? - # Maybe ... q.v. above - binmode $fh; # for win32 - - if ($self->_root->{autoflush}) { - my $old = select $fh; - $|=1; - select $old; - } - - # Set the - seek($fh, 0, SEEK_SET); - - my $signature; - my $bytes_read = read( $fh, $signature, length(SIG_FILE)); - - ## - # File is empty -- write signature and master index - ## - if (!$bytes_read) { - seek($fh, 0, SEEK_SET); - print($fh SIG_FILE); - $self->_create_tag($self->_base_offset, $self->_type, chr(0) x $INDEX_SIZE); - - my $plain_key = "[base]"; - print($fh pack($DATA_LENGTH_PACK, length($plain_key)) . $plain_key ); - - # Flush the filehandle - my $old_fh = select $fh; - my $old_af = $|; - $| = 1; - $| = $old_af; - select $old_fh; - - my @stats = stat($fh); - $self->_root->{inode} = $stats[1]; - $self->_root->{end} = $stats[7]; - - return 1; - } - - ## - # Check signature was valid - ## - unless ($signature eq SIG_FILE) { - $self->_close(); - return $self->_throw_error("Signature not found -- file is not a Deep DB"); - } - - my @stats = stat($fh); - $self->_root->{inode} = $stats[1]; - $self->_root->{end} = $stats[7]; - - ## - # Get our type from master index signature - ## - my $tag = $self->_load_tag($self->_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 $self->_throw_error("Corrupted file, no master index record"); - } - if ($self->{type} ne $tag->{signature}) { - return $self->_throw_error("File type mismatch"); - } - - return 1; -} - -sub _close { - ## - # Close database fh - ## - my $self = $_[0]->_get_self; - close $self->_root->{fh} if $self->_root->{fh}; - $self->_root->{fh} = undef; -} - -sub _create_tag { - ## - # Given offset, signature and content, create tag and write to disk - ## - my ($self, $offset, $sig, $content) = @_; - my $size = length($content); - - my $fh = $self->_fh; - - seek($fh, $offset, SEEK_SET); - print($fh $sig . pack($DATA_LENGTH_PACK, $size) . $content ); - - if ($offset == $self->_root->{end}) { - $self->_root->{end} += SIG_SIZE + $DATA_LENGTH_SIZE + $size; - } - - return { - signature => $sig, - size => $size, - offset => $offset + SIG_SIZE + $DATA_LENGTH_SIZE, - content => $content - }; -} - -sub _load_tag { - ## - # Given offset, load single tag and return signature, size and data - ## - my $self = shift; - my $offset = shift; - - my $fh = $self->_fh; - - seek($fh, $offset, SEEK_SET); - if (eof $fh) { return undef; } - - my $sig; - read( $fh, $sig, SIG_SIZE); - - my $size; - read( $fh, $size, $DATA_LENGTH_SIZE); - $size = unpack($DATA_LENGTH_PACK, $size); - - my $buffer; - read( $fh, $buffer, $size); - - return { - signature => $sig, - size => $size, - offset => $offset + SIG_SIZE + $DATA_LENGTH_SIZE, - content => $buffer - }; -} - -sub _index_lookup { - ## - # Given index tag, lookup single entry in index and return . - ## - my $self = shift; - my ($tag, $index) = @_; - - my $location = unpack($LONG_PACK, substr($tag->{content}, $index * $LONG_SIZE, $LONG_SIZE) ); - if (!$location) { return; } - - return $self->_load_tag( $location ); -} - -sub _add_bucket { - ## - # Adds one key/value pair to bucket list, given offset, MD5 digest of key, - # plain (undigested) key and value. - ## - my $self = shift; - my ($tag, $md5, $plain_key, $value) = @_; - my $keys = $tag->{content}; - my $location = 0; - my $result = 2; - - # added ref() check first to avoid eval and runtime exception for every - # scalar value being stored. performance tweak. - my $is_dbm_deep = eval { local $SIG{'__DIE__'}; $value->isa( 'DBM::Deep' ) }; - - my $internal_ref = $is_dbm_deep && ($value->_root eq $self->_root); - - my $fh = $self->_fh; - - ## - # Iterate through buckets, seeing if this is a new entry or a replace. - ## - 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) { - ## - # Found empty bucket (end of list). Populate and exit loop. - ## - $result = 2; - - $location = $internal_ref - ? $value->_base_offset - : $self->_root->{end}; - - seek($fh, $tag->{offset} + ($i * $BUCKET_SIZE), SEEK_SET); - print($fh $md5 . pack($LONG_PACK, $location) ); - last; - } - elsif ($md5 eq $key) { - ## - # Found existing bucket with same key. Replace with new value. - ## - $result = 1; - - if ($internal_ref) { - $location = $value->_base_offset; - seek($fh, $tag->{offset} + ($i * $BUCKET_SIZE), SEEK_SET); - print($fh $md5 . pack($LONG_PACK, $location) ); - } - else { - seek($fh, $subloc + SIG_SIZE, SEEK_SET); - my $size; - read( $fh, $size, $DATA_LENGTH_SIZE); $size = unpack($DATA_LENGTH_PACK, $size); - - ## - # If value is a hash, array, or raw value with equal or less size, we can - # reuse the same content area of the database. Otherwise, we have to create - # a new content area at the EOF. - ## - my $actual_length; - my $r = Scalar::Util::reftype( $value ) || ''; - if ( $r eq 'HASH' || $r eq 'ARRAY' ) { - $actual_length = $INDEX_SIZE; - - # if autobless is enabled, must also take into consideration - # the class name, as it is stored along with key/value. - if ( $self->_root->{autobless} ) { - my $value_class = Scalar::Util::blessed($value); - if ( defined $value_class && $value_class ne 'DBM::Deep' ) { - $actual_length += length($value_class); - } - } # autobless - } - else { $actual_length = length($value); } - - if ($actual_length <= $size) { - $location = $subloc; - } - else { - $location = $self->_root->{end}; - seek($fh, $tag->{offset} + ($i * $BUCKET_SIZE) + $HASH_SIZE, SEEK_SET); - print($fh pack($LONG_PACK, $location) ); - } - } - last; - } - } # i loop - - ## - # If this is an internal reference, return now. - # No need to write value or plain key - ## - if ($internal_ref) { - return $result; - } - - ## - # If bucket didn't fit into list, split into a new index level - ## - if (!$location) { - seek($fh, $tag->{ref_loc}, SEEK_SET); - print($fh pack($LONG_PACK, $self->_root->{end}) ); - - my $index_tag = $self->_create_tag($self->_root->{end}, SIG_INDEX, chr(0) x $INDEX_SIZE); - my @offsets = (); - - $keys .= $md5 . pack($LONG_PACK, 0); - - for (my $i=0; $i<=$MAX_BUCKETS; $i++) { - my $key = substr($keys, $i * $BUCKET_SIZE, $HASH_SIZE); - if ($key) { - my $old_subloc = unpack($LONG_PACK, substr($keys, ($i * $BUCKET_SIZE) + $HASH_SIZE, $LONG_SIZE)); - my $num = ord(substr($key, $tag->{ch} + 1, 1)); - - if ($offsets[$num]) { - my $offset = $offsets[$num] + SIG_SIZE + $DATA_LENGTH_SIZE; - seek($fh, $offset, SEEK_SET); - my $subkeys; - read( $fh, $subkeys, $BUCKET_LIST_SIZE); - - for (my $k=0; $k<$MAX_BUCKETS; $k++) { - my $subloc = unpack($LONG_PACK, substr($subkeys, ($k * $BUCKET_SIZE) + $HASH_SIZE, $LONG_SIZE)); - if (!$subloc) { - seek($fh, $offset + ($k * $BUCKET_SIZE), SEEK_SET); - print($fh $key . pack($LONG_PACK, $old_subloc || $self->_root->{end}) ); - last; - } - } # k loop - } - else { - $offsets[$num] = $self->_root->{end}; - seek($fh, $index_tag->{offset} + ($num * $LONG_SIZE), SEEK_SET); - print($fh pack($LONG_PACK, $self->_root->{end}) ); - - my $blist_tag = $self->_create_tag($self->_root->{end}, SIG_BLIST, chr(0) x $BUCKET_LIST_SIZE); - - seek($fh, $blist_tag->{offset}, SEEK_SET); - print($fh $key . pack($LONG_PACK, $old_subloc || $self->_root->{end}) ); - } - } # key is real - } # i loop - - $location ||= $self->_root->{end}; - } # re-index bucket list - - ## - # Seek to content area and store signature, value and plaintext key - ## - if ($location) { - my $content_length; - seek($fh, $location, SEEK_SET); - - ## - # Write signature based on content type, set content length and write actual value. - ## - my $r = Scalar::Util::reftype($value) || ''; - if ($r eq 'HASH') { - print($fh TYPE_HASH ); - print($fh pack($DATA_LENGTH_PACK, $INDEX_SIZE) . chr(0) x $INDEX_SIZE ); - $content_length = $INDEX_SIZE; - } - elsif ($r eq 'ARRAY') { - print($fh TYPE_ARRAY ); - print($fh pack($DATA_LENGTH_PACK, $INDEX_SIZE) . chr(0) x $INDEX_SIZE ); - $content_length = $INDEX_SIZE; - } - elsif (!defined($value)) { - print($fh SIG_NULL ); - print($fh pack($DATA_LENGTH_PACK, 0) ); - $content_length = 0; - } - else { - print($fh SIG_DATA ); - print($fh pack($DATA_LENGTH_PACK, length($value)) . $value ); - $content_length = length($value); - } - - ## - # Plain key is stored AFTER value, as keys are typically fetched less often. - ## - print($fh pack($DATA_LENGTH_PACK, length($plain_key)) . $plain_key ); - - ## - # If value is blessed, preserve class name - ## - if ( $self->_root->{autobless} ) { - my $value_class = Scalar::Util::blessed($value); - if ( defined $value_class && $value_class ne 'DBM::Deep' ) { - ## - # Blessed ref -- will restore later - ## - print($fh chr(1) ); - print($fh pack($DATA_LENGTH_PACK, length($value_class)) . $value_class ); - $content_length += 1; - $content_length += $DATA_LENGTH_SIZE + length($value_class); - } - else { - print($fh chr(0) ); - $content_length += 1; - } - } - - ## - # If this is a new content area, advance EOF counter - ## - if ($location == $self->_root->{end}) { - $self->_root->{end} += SIG_SIZE; - $self->_root->{end} += $DATA_LENGTH_SIZE + $content_length; - $self->_root->{end} += $DATA_LENGTH_SIZE + length($plain_key); - } - - ## - # If content is a hash or array, create new child DBM::Deep object and - # pass each key or element to it. - ## - if ($r eq 'HASH') { - my $branch = DBM::Deep->new( - type => TYPE_HASH, - base_offset => $location, - root => $self->_root, - ); - foreach my $key (keys %{$value}) { - $branch->STORE( $key, $value->{$key} ); - } - } - elsif ($r eq 'ARRAY') { - my $branch = DBM::Deep->new( - type => TYPE_ARRAY, - base_offset => $location, - root => $self->_root, - ); - my $index = 0; - foreach my $element (@{$value}) { - $branch->STORE( $index, $element ); - $index++; - } - } - - return $result; - } - - return $self->_throw_error("Fatal error: indexing failed -- possibly due to corruption in file"); -} - -sub _get_bucket_value { - ## - # Fetch single value given tag and MD5 digested key. - ## - my $self = shift; - my ($tag, $md5) = @_; - my $keys = $tag->{content}; - - my $fh = $self->_fh; - - ## - # 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, $LONG_SIZE)); - - if (!$subloc) { - ## - # Hit end of list, no match - ## - return; - } - - if ( $md5 ne $key ) { - next BUCKET; - } - - ## - # Found match -- seek to offset and read signature - ## - my $signature; - seek($fh, $subloc, SEEK_SET); - read( $fh, $signature, SIG_SIZE); - - ## - # If value is a hash or array, return new DBM::Deep object with correct offset - ## - if (($signature eq TYPE_HASH) || ($signature eq TYPE_ARRAY)) { - my $obj = DBM::Deep->new( - type => $signature, - base_offset => $subloc, - root => $self->_root - ); - - if ($self->_root->{autobless}) { - ## - # Skip over value and plain key to see if object needs - # to be re-blessed - ## - seek($fh, $DATA_LENGTH_SIZE + $INDEX_SIZE, SEEK_CUR); - - my $size; - read( $fh, $size, $DATA_LENGTH_SIZE); $size = unpack($DATA_LENGTH_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, $size); - if ($size) { read( $fh, $class_name, $size); } - if ($class_name) { $obj = bless( $obj, $class_name ); } - } - } - - return $obj; - } - - ## - # Otherwise return actual value - ## - elsif ($signature eq SIG_DATA) { - my $size; - my $value = ''; - read( $fh, $size, $DATA_LENGTH_SIZE); $size = unpack($DATA_LENGTH_PACK, $size); - if ($size) { read( $fh, $value, $size); } - return $value; - } - - ## - # Key exists, but content is null - ## - else { return; } - } # i loop - - return; -} - -sub _delete_bucket { - ## - # Delete single key/value pair given tag and MD5 digested key. - ## - my $self = shift; - my ($tag, $md5) = @_; - my $keys = $tag->{content}; - - my $fh = $self->_fh; - - ## - # 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, $LONG_SIZE)); - - if (!$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 * $BUCKET_SIZE), SEEK_SET); - print($fh substr($keys, ($i+1) * $BUCKET_SIZE ) ); - print($fh chr(0) x $BUCKET_SIZE ); - - return 1; - } # i loop - - return; -} - -sub _bucket_exists { - ## - # Check existence of single key given tag and MD5 digested key. - ## - my $self = shift; - my ($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, $LONG_SIZE)); - - if (!$subloc) { - ## - # Hit end of list, no match - ## - return; - } - - if ( $md5 ne $key ) { - next BUCKET; - } - - ## - # Matched key -- return true - ## - return 1; - } # i loop - - return; -} - sub _find_bucket_list { ## # Locate offset for bucket list, given digested key @@ -800,11 +214,11 @@ sub _find_bucket_list { # Locate offset for bucket list using digest index system ## my $ch = 0; - my $tag = $self->_load_tag($self->_base_offset); + my $tag = $self->{engine}->load_tag($self, $self->_base_offset); if (!$tag) { return; } while ($tag->{signature} ne SIG_BLIST) { - $tag = $self->_index_lookup($tag, ord(substr($md5, $ch, 1))); + $tag = $self->{engine}->index_lookup($self, $tag, ord(substr($md5, $ch, 1))); if (!$tag) { return; } $ch++; } @@ -819,7 +233,7 @@ sub _traverse_index { my ($self, $offset, $ch, $force_return_next) = @_; $force_return_next = undef unless $force_return_next; - my $tag = $self->_load_tag( $offset ); + my $tag = $self->{engine}->load_tag($self, $offset ); my $fh = $self->_fh; @@ -869,7 +283,7 @@ sub _traverse_index { ## # Seek to bucket location and skip over signature ## - seek($fh, $subloc + SIG_SIZE, SEEK_SET); + seek($fh, $subloc + SIG_SIZE + $self->_root->{file_offset}, SEEK_SET); ## # Skip over value to get to plain key @@ -939,7 +353,7 @@ sub lock { # double-check file inode, in case another process # has optimize()d our file while we were waiting. if ($stats[1] != $self->_root->{inode}) { - $self->_open(); # re-open + $self->{engine}->open( $self ); # re-open flock($self->_fh, $type); # re-lock $self->_root->{end} = (stat($self->_fh))[7]; # re-end } @@ -992,7 +406,7 @@ sub _copy_value { else { ${$spot} = { %{$value} }; } - $$spot = bless $$spot, $c + ${$spot} = bless ${$spot}, $c if defined $c; } @@ -1121,7 +535,7 @@ sub optimize { # with a soft copy. ## $self->unlock(); - $self->_close(); + $self->{engine}->close( $self ); } if (!rename $self->_root->{file} . '.tmp', $self->_root->{file}) { @@ -1131,8 +545,8 @@ sub optimize { } $self->unlock(); - $self->_close(); - $self->_open(); + $self->{engine}->close( $self ); + $self->{engine}->open( $self ); return 1; } @@ -1212,49 +626,12 @@ sub _base_offset { return $self->{base_offset}; } -sub error { - ## - # Get last error string, or undef if no error - ## - return $_[0] - #? ( _get_self($_[0])->{root}->{error} or undef ) - ? ( $_[0]->_get_self->{root}->{error} or undef ) - : $@; -} - ## # Utility methods ## sub _throw_error { - ## - # Store error string in self - ## - my $error_text = $_[1]; - - if ( Scalar::Util::blessed $_[0] ) { - my $self = $_[0]->_get_self; - $self->_root->{error} = $error_text; - - unless ($self->_root->{debug}) { - die "DBM::Deep: $error_text\n"; - } - - warn "DBM::Deep: $error_text\n"; - return; - } - else { - die "DBM::Deep: $error_text\n"; - } -} - -sub clear_error { - ## - # Clear error state - ## - my $self = $_[0]->_get_self; - - undef $self->_root->{error}; + die "DBM::Deep: $_[1]\n"; } sub _precalc_sizes { @@ -1297,6 +674,16 @@ sub set_digest { _precalc_sizes(); } +sub _is_writable { + my $fh = shift; + (O_WRONLY | O_RDWR) & fcntl( $fh, F_GETFL, my $slush = 0); +} + +#sub _is_readable { +# my $fh = shift; +# (O_RDONLY | O_RDWR) & fcntl( $fh, F_GETFL, my $slush = 0); +#} + ## # tie() methods (hashes and arrays) ## @@ -1316,13 +703,9 @@ sub STORE { my $md5 = $DIGEST_FUNC->($key); - ## - # Make sure file is open - ## - if (!defined($self->_fh) && !$self->_open()) { - return; - } - ## + unless ( _is_writable( $self->_fh ) ) { + $self->_throw_error( 'Cannot write to a readonly filehandle' ); + } ## # Request exclusive lock for writing @@ -1334,28 +717,32 @@ sub STORE { ## # Locate offset for bucket list using digest index system ## - my $tag = $self->_load_tag($self->_base_offset); + my $tag = $self->{engine}->load_tag($self, $self->_base_offset); if (!$tag) { - $tag = $self->_create_tag($self->_base_offset, SIG_INDEX, chr(0) x $INDEX_SIZE); + $tag = $self->{engine}->create_tag($self, $self->_base_offset, SIG_INDEX, chr(0) x $INDEX_SIZE); } my $ch = 0; while ($tag->{signature} ne SIG_BLIST) { my $num = ord(substr($md5, $ch, 1)); - my $new_tag = $self->_index_lookup($tag, $num); + + my $ref_loc = $tag->{offset} + ($num * $LONG_SIZE); + my $new_tag = $self->{engine}->index_lookup($self, $tag, $num); + if (!$new_tag) { - my $ref_loc = $tag->{offset} + ($num * $LONG_SIZE); - seek($fh, $ref_loc, SEEK_SET); - print($fh pack($LONG_PACK, $self->_root->{end}) ); + seek($fh, $ref_loc + $self->_root->{file_offset}, SEEK_SET); + print( $fh pack($LONG_PACK, $self->_root->{end}) ); - $tag = $self->_create_tag($self->_root->{end}, SIG_BLIST, chr(0) x $BUCKET_LIST_SIZE); + $tag = $self->{engine}->create_tag($self, $self->_root->{end}, SIG_BLIST, chr(0) x $BUCKET_LIST_SIZE); + $tag->{ref_loc} = $ref_loc; $tag->{ch} = $ch; + last; } else { - my $ref_loc = $tag->{offset} + ($num * $LONG_SIZE); $tag = $new_tag; + $tag->{ref_loc} = $ref_loc; $tag->{ch} = $ch; } @@ -1365,7 +752,7 @@ sub STORE { ## # Add key/value to bucket list ## - my $result = $self->_add_bucket( $tag, $md5, $key, $value ); + my $result = $self->{engine}->add_bucket( $self, $tag, $md5, $key, $value ); $self->unlock(); @@ -1379,11 +766,6 @@ sub FETCH { my $self = shift->_get_self; my $key = shift; - ## - # Make sure file is open - ## - if (!defined($self->_fh)) { $self->_open(); } - my $md5 = $DIGEST_FUNC->($key); ## @@ -1400,7 +782,7 @@ sub FETCH { ## # Get value from bucket list ## - my $result = $self->_get_bucket_value( $tag, $md5 ); + my $result = $self->{engine}->get_bucket_value( $self, $tag, $md5 ); $self->unlock(); @@ -1422,11 +804,6 @@ sub DELETE { my $md5 = $DIGEST_FUNC->($key); ## - # Make sure file is open - ## - if (!defined($self->_fh)) { $self->_open(); } - - ## # Request exclusive lock for writing ## $self->lock( LOCK_EX ); @@ -1440,12 +817,12 @@ sub DELETE { ## # Delete bucket ## - my $value = $self->_get_bucket_value( $tag, $md5 ); + my $value = $self->{engine}->get_bucket_value($self, $tag, $md5 ); if ($value && !ref($value) && $self->_root->{filter_fetch_value}) { $value = $self->_root->{filter_fetch_value}->($value); } - my $result = $self->_delete_bucket( $tag, $md5 ); + my $result = $self->{engine}->delete_bucket( $self, $tag, $md5 ); ## # If this object is an array and the key deleted was on the end of the stack, @@ -1467,11 +844,6 @@ sub EXISTS { my $md5 = $DIGEST_FUNC->($key); ## - # Make sure file is open - ## - if (!defined($self->_fh)) { $self->_open(); } - - ## # Request shared lock for reading ## $self->lock( LOCK_SH ); @@ -1489,7 +861,7 @@ sub EXISTS { ## # Check if bucket exists and return 1 or '' ## - my $result = $self->_bucket_exists( $tag, $md5 ) || ''; + my $result = $self->{engine}->bucket_exists( $self, $tag, $md5 ) || ''; $self->unlock(); @@ -1503,24 +875,19 @@ sub CLEAR { my $self = $_[0]->_get_self; ## - # Make sure file is open - ## - if (!defined($self->_fh)) { $self->_open(); } - - ## # Request exclusive lock for writing ## $self->lock( LOCK_EX ); my $fh = $self->_fh; - seek($fh, $self->_base_offset, SEEK_SET); + seek($fh, $self->_base_offset + $self->_root->{file_offset}, SEEK_SET); if (eof $fh) { $self->unlock(); return; } - $self->_create_tag($self->_base_offset, $self->_type, chr(0) x $INDEX_SIZE); + $self->{engine}->create_tag($self, $self->_base_offset, $self->_type, chr(0) x $INDEX_SIZE); $self->unlock(); @@ -1547,6 +914,7 @@ sub new { my $self = bless { file => undef, fh => undef, + file_offset => 0, end => 0, autoflush => undef, locking => undef, @@ -1560,6 +928,10 @@ sub new { %$args, }, $class; + if ( $self->{fh} && !$self->{file_offset} ) { + $self->{file_offset} = tell( $self->{fh} ); + } + return $self; } @@ -1700,7 +1072,26 @@ DBM::Deep objects. These apply to both the OO- and tie- based approaches. Filename of the DB file to link the handle to. You can pass a full absolute filesystem path, partial path, or a plain filename if the file is in the -current working directory. This is a required parameter. +current working directory. This is a required parameter (though q.v. fh). + +=item * fh + +If you want, you can pass in the fh instead of the file. This is most useful for doing +something like: + + my $db = DBM::Deep->new( { fh => \*DATA } ); + +You are responsible for making sure that the fh has been opened appropriately for your +needs. If you open it read-only and attempt to write, an exception will be thrown. If you +open it write-only or append-only, an exception will be thrown immediately as DBM::Deep +needs to read from the fh. + +=item * file_offset + +This is the offset within the file that the DBM::Deep db starts. Most of the time, you will +not need to set this. However, it's there if you want it. + +If you pass in fh and do not set this, it will be set appropriately. =item * type @@ -1744,15 +1135,7 @@ Setting I mode will make all errors non-fatal, dump them out to STDERR, and continue on. This is for debugging purposes only, and probably not what you want. This is an optional parameter, and defaults to 0 (disabled). -=item * fh - -Instead of passing a file path, you can instead pass a handle to an pre-opened -filehandle. Note: Beware of using the magick *DATA handle, as this actually -contains your entire Perl script, as well as the data following the __DATA__ -marker. This will not work, because DBM::Deep uses absolute seek()s into the -file. Instead, consider reading *DATA into an IO::Scalar handle, then passing -in that. Also please note optimize() will NOT work when passing in only a -handle. Pass in a real filename in order to use optimize(). +B: This parameter is considered deprecated and should not be used anymore. =back @@ -1907,10 +1290,6 @@ Data going in and out. q.v. adjusting the interal parameters. -=item * error() / clear_error() - -Error handling methods (may be deprecated). -. =back =head2 HASHES @@ -2282,24 +1661,12 @@ actually numerical index numbers, and are not filtered. =head1 ERROR HANDLING Most DBM::Deep methods return a true value for success, and call die() on -failure. You can wrap calls in an eval block to catch the die. Also, the -actual error message is stored in an internal scalar, which can be fetched by -calling the C method. +failure. You can wrap calls in an eval block to catch the die. my $db = DBM::Deep->new( "foo.db" ); # create hash eval { $db->push("foo"); }; # ILLEGAL -- push is array-only call print $@; # prints error message - print $db->error(); # prints error message - -You can then call C to clear the current error state. - - $db->clear_error(); - -If you set the C option to true when creating your DBM::Deep object, -all errors are considered NON-FATAL, and dumped to STDERR. This should only -be used for debugging purposes and not production work. DBM::Deep expects errors -to be thrown, not propagated back up the stack. =head1 LARGEFILE SUPPORT @@ -2496,6 +1863,13 @@ These functions cause every element in the array to move, which can be murder on DBM::Deep, as every element has to be fetched from disk, then stored again in a different location. This will be addressed in the forthcoming version 1.00. +=head2 WRITEONLY FILES + +If you pass in a filehandle to new(), you may have opened it in either a readonly or +writeonly mode. STORE will verify that the filehandle is writable. However, there +doesn't seem to be a good way to determine if a filehandle is readable. And, if the +filehandle isn't readable, it's not clear what will happen. So, don't do that. + =head1 PERFORMANCE This section discusses DBM::Deep's speed and memory usage. @@ -2698,10 +2072,10 @@ B report on this module's test suite. ---------------------------- ------ ------ ------ ------ ------ ------ ------ File stmt bran cond sub pod time total ---------------------------- ------ ------ ------ ------ ------ ------ ------ - blib/lib/DBM/Deep.pm 94.1 82.5 68.7 98.1 100.0 58.0 89.9 - blib/lib/DBM/Deep/Array.pm 98.9 88.9 87.5 100.0 n/a 28.9 96.4 - blib/lib/DBM/Deep/Hash.pm 95.3 80.0 100.0 100.0 n/a 13.2 92.4 - Total 95.1 83.4 72.8 98.8 100.0 100.0 91.3 + blib/lib/DBM/Deep.pm 95.2 83.8 70.0 98.2 100.0 58.0 91.0 + blib/lib/DBM/Deep/Array.pm 100.0 91.1 100.0 100.0 n/a 26.7 98.0 + blib/lib/DBM/Deep/Hash.pm 95.3 80.0 100.0 100.0 n/a 15.3 92.4 + Total 96.2 84.8 74.4 98.8 100.0 100.0 92.4 ---------------------------- ------ ------ ------ ------ ------ ------ ------ =head1 MORE INFORMATION