Merge pull request #1 from charsbar/tie

tie interface

lib/UnQLite.pm

@@ -2,6 +2,7 @@ package UnQLite;
 use 5.008005;
 use strict;
 use warnings;
+use Carp ();
 
 our $VERSION = "0.01";
 our $rc = 0;
@@ -9,6 +10,12 @@ our $rc = 0;
 use XSLoader;
 XSLoader::load(__PACKAGE__, $VERSION);
 
+sub TIEHASH {
+    my $class = shift;
+    my $self = $class->open(@_) or Carp::croak $class->errstr;
+    $self->cursor_init;
+}
+
 sub rc { $UnQLite::rc }
 
 sub errstr {
@@ -96,6 +103,62 @@ sub DESTROY {
     _release($self->[0], $self->[1]);
 }
 
+# tie interface
+
+sub FETCH {
+    my ($self, $key) = @_;
+    $self->[1]->kv_fetch($key);
+}
+
+sub STORE {
+    my ($self, $key, $value) = @_;
+    $self->[1]->kv_store($key, $value) or Carp::croak $self->[1]->errstr;
+    $value;
+}
+
+sub DELETE {
+    my ($self, $key) = @_;
+    my $prev = $self->[1]->kv_fetch($key);
+    my $errstr = $self->[1]->errstr;
+    return unless $errstr && $errstr eq 'UNQLITE_OK';
+    $self->[1]->kv_delete($key) or Carp::croak $self->[1]->errstr;
+    $prev;
+}
+
+sub FIRSTKEY {
+    my $self = shift;
+    $self->first_entry or return;
+    $self->key;
+}
+
+sub NEXTKEY {
+    my $self = shift;
+    $self->next_entry or return;
+    $self->key;
+}
+
+sub EXISTS {
+    my ($self, $key) = @_;
+    $self->[1]->kv_fetch($key) and return 1;
+    my $errstr = $self->[1]->errstr;
+    return $errstr && $errstr eq 'UNQLITE_OK' ? 1 : 0;
+}
+
+sub CLEAR {
+    my $self = shift;
+    $self->first_entry or return;
+    $self->delete_entry while $self->valid_entry;
+    return;
+}
+
+sub SCALAR {
+    my $self = shift;
+    $self->first_entry or return;
+    my $ct = 1;
+    $ct++ while $self->next_entry && $self->valid_entry;
+    return $ct;
+}
+
 1;
 __END__
 
@@ -117,6 +180,11 @@ UnQLite - Perl bindings for UnQLite
     $db->kv_delete('foo');
     undef $db; # close database
 
+    # tie interface
+    tie my %hash, 'UnQLite', 'foo.db';
+    $hash{foo} = 'bar';
+    say $hash{foo}; # => bar
+
 =head1 DESCRIPTION
 
 UnQLite is a in-process software library which implements a self-contained, serverless, zero-configuration, transactional NoSQL database engine. UnQLite is a document store database similar to MongoDB, Redis, CouchDB etc. as well a standard Key/Value store similar to BerkeleyDB, LevelDB, etc.  

t/03_tie.t

@@ -0,0 +1,46 @@
+use strict;
+use Test::More;
+
+use File::Temp qw(tempdir);
+use UnQLite;
+
+my $tmp = tempdir( CLEANUP => 1 );
+
+{
+    my $db = UnQLite->open("$tmp/foo.db");
+    isa_ok($db, 'UnQLite');
+
+    ok($db->kv_store("foo", "bar"));
+    is($db->kv_fetch('foo'), 'bar');
+    ok($db->kv_delete('foo'));
+    is($db->kv_fetch('foo'), undef);
+    $db->kv_store('yay', 'yap');
+    $db->kv_append('yay', 'po');
+    is($db->kv_fetch('yay'), 'yappo');
+    is($db->rc,0);
+}
+
+{
+    ok -e "$tmp/foo.db", "foo.db exists";
+    tie my %hash, 'UnQLite', "$tmp/foo.db";
+
+    # stored data can be retrieved again?
+    is($hash{yay}, 'yappo');
+    $hash{foo} = 'baz';
+    is($hash{foo}, 'baz');
+    $hash{delete} = 'delete';
+    is(delete $hash{delete}, 'delete');
+    is(delete $hash{delete}, undef);
+    ok(exists $hash{foo});
+    ok(!exists $hash{delete});
+
+    is(join(" ", sort keys %hash), "foo yay");
+    is(join(" ", sort values %hash), "baz yappo");
+    is(scalar %hash, 2);
+    %hash = ();
+    is(join(" ", sort keys %hash), "");
+    is(join(" ", sort values %hash), "");
+    is(scalar %hash, undef);
+}
+
+done_testing;