From: rkinyon <rkinyon@50811bd7-b8ce-0310-adc1-d9db26280581>
Date: Wed, 29 Nov 2006 04:24:15 +0000 (+0000)
Subject: Added delete
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=e86cef3618b604b18989c11f9b473028805c6769;p=dbsrgits%2FDBM-Deep.git

Added delete
---

diff --git a/lib/DBM/Deep/Engine3.pm b/lib/DBM/Deep/Engine3.pm
index cb9fd0e..6c4341b 100644
--- a/lib/DBM/Deep/Engine3.pm
+++ b/lib/DBM/Deep/Engine3.pm
@@ -119,6 +119,7 @@ sub read_value {
     die "How did this fail (no blist)?!\n" unless $blist;
 
     my $value_sector = $blist->get_data_for( $key_md5 );
+    return if ! $value_sector;
 
     return $value_sector->data;
 }
@@ -139,12 +140,26 @@ sub key_exists {
     });
     die "How did this fail (no blist)?!\n" unless $blist;
 
-    my $value_sector = $blist->get_data_for( $key_md5 );
+    # exists() returns 1 or '' for true/false.
+    return $blist->has_md5( $key_md5 ) ? 1 : '';
 }
 
 sub delete_key {
     my $self = shift;
     my ($trans_id, $base_offset, $key) = @_;
+
+    my $sector = $self->_load_sector( $base_offset );
+    die "How did this fail (no sector for '$base_offset')?!\n" unless $sector;
+
+    my $key_md5 = $self->_apply_digest( $key );
+
+    # XXX What should happen if this fails?
+    my $blist = $sector->get_bucket_list({
+        key_md5 => $key_md5,
+    });
+    die "How did this fail (no blist)?!\n" unless $blist;
+
+    return $blist->delete_md5( $key_md5 );
 }
 
 sub write_value {
@@ -591,16 +606,39 @@ sub write_md5 {
     );
 }
 
-sub get_data_for {
+sub delete_md5 {
     my $self = shift;
     my ($md5) = @_;
 
+    my $engine = $self->engine;
     my ($found, $idx) = $self->find_md5( $md5 );
-    return unless $found;
+    return 1 unless $found;
+    my $location = $self->get_location_for( $idx );
+    $engine->storage->print_at( $self->offset + $self->base_size + $idx * $self->bucket_size,
+        $self->engine->blank_md5,            # The blank MD5
+        pack( $StP{$engine->byte_size}, 0 ), # The pointer to the data in the HEAD
+    );
+
+    return 1;
+}
+
+sub get_location_for {
+    my $self = shift;
+    my ($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 );
+    return unpack( $StP{$self->engine->byte_size}, $location );
+}
+
+sub get_data_for {
+    my $self = shift;
+    my ($md5) = @_;
+
+    my ($found, $idx) = $self->find_md5( $md5 );
+    return unless $found;
+    my $location = $self->get_location_for( $idx );
     return $self->engine->_load_sector( $location );
 }
 
diff --git a/t/02_hash.t b/t/02_hash.t
index da9f221..19e26de 100644
--- a/t/02_hash.t
+++ b/t/02_hash.t
@@ -33,7 +33,6 @@ is( $db->{key3}, 'value3', "... and hash-access also works" );
 is( $db->{key1}, "value1", "Key1 is still correct" );
 is( $db->{key2}, undef, "Key2 is still correct" );
 is( $db->{key3}, 'value3', "Key3 is still correct" );
-__END__
 
 ok( $db->exists("key1"), "exists() function works" );
 ok( exists $db->{key2}, "exists() works against tied hash" );
@@ -44,9 +43,10 @@ TODO: {
     local $TODO = "Autovivification isn't correct yet";
     ok( exists $db->{key4}, "Autovivified key4 now exists" );
 }
+
 delete $db->{key4};
 ok( !exists $db->{key4}, "And key4 doesn't exists anymore" );
-
+__END__
 ##
 # count keys
 ##