From 008d6ea2f33b4fe6dbacd7aa981e95d69a13e426 Mon Sep 17 00:00:00 2001
From: Kenichi Ishigaki <ishigaki@cpan.org>
Date: Thu, 4 Jul 2013 13:20:58 +0900
Subject: [PATCH 1/5] tie interface

---
 lib/UnQLite.pm | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++
 t/03_tie.t     | 41 +++++++++++++++++++++++++++++++
 2 files changed, 107 insertions(+)
 create mode 100644 t/03_tie.t

diff --git a/lib/UnQLite.pm b/lib/UnQLite.pm
index 04c1a2d..93f932a 100644
--- a/lib/UnQLite.pm
+++ b/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 croak $class->errstr;
+    $self->cursor_init;
+}
+
 sub rc { $UnQLite::rc }
 
 sub errstr {
@@ -96,6 +103,60 @@ 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 croak $self->[1]->errstr;
+    $value;
+}
+
+sub DELETE {
+    my ($self, $key) = @_;
+    my $prev = $self->kv_fetch($key);
+    $self->[1]->kv_delete($key) or 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);
+    my $errstr = $self->[1]->errstr;
+    return $errstr eq 'UNQLITE_NOTFOUND' ? 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 +178,11 @@ 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.  
diff --git a/t/03_tie.t b/t/03_tie.t
new file mode 100644
index 0000000..7ccf39e
--- /dev/null
+++ b/t/03_tie.t
@@ -0,0 +1,41 @@
+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');
+
+    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;

From 317b78815a4f8571a5762438d38ada506dee910a Mon Sep 17 00:00:00 2001
From: Kenichi Ishigaki <ishigaki@cpan.org>
Date: Thu, 4 Jul 2013 13:23:50 +0900
Subject: [PATCH 2/5] oops

---
 lib/UnQLite.pm | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/UnQLite.pm b/lib/UnQLite.pm
index 93f932a..04c55fb 100644
--- a/lib/UnQLite.pm
+++ b/lib/UnQLite.pm
@@ -12,7 +12,7 @@ XSLoader::load(__PACKAGE__, $VERSION);
 
 sub TIEHASH {
     my $class = shift;
-    my $self = $class->open(@_) or croak $class->errstr;
+    my $self = $class->open(@_) or Carp::croak $class->errstr;
     $self->cursor_init;
 }
 
@@ -112,14 +112,14 @@ sub FETCH {
 
 sub STORE {
     my ($self, $key, $value) = @_;
-    $self->[1]->kv_store($key, $value) or croak $self->[1]->errstr;
+    $self->[1]->kv_store($key, $value) or Carp::croak $self->[1]->errstr;
     $value;
 }
 
 sub DELETE {
     my ($self, $key) = @_;
     my $prev = $self->kv_fetch($key);
-    $self->[1]->kv_delete($key) or croak $self->[1]->errstr;
+    $self->[1]->kv_delete($key) or Carp::croak $self->[1]->errstr;
     $prev;
 }
 

From a94bdc6ca250cf5144a5c9a20d90b6cbbd0eb0c6 Mon Sep 17 00:00:00 2001
From: Kenichi Ishigaki <ishigaki@cpan.org>
Date: Thu, 4 Jul 2013 13:32:39 +0900
Subject: [PATCH 3/5] fixed DELETE for a nonexistent entry

---
 lib/UnQLite.pm | 4 +++-
 t/03_tie.t     | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/UnQLite.pm b/lib/UnQLite.pm
index 04c55fb..3868d37 100644
--- a/lib/UnQLite.pm
+++ b/lib/UnQLite.pm
@@ -118,7 +118,9 @@ sub STORE {
 
 sub DELETE {
     my ($self, $key) = @_;
-    my $prev = $self->kv_fetch($key);
+    my $prev = $self->[1]->kv_fetch($key);
+    my $errstr = $self->[1]->errstr;
+    return if $errstr && $errstr eq 'UNQLITE_NOTFOUND';
     $self->[1]->kv_delete($key) or Carp::croak $self->[1]->errstr;
     $prev;
 }
diff --git a/t/03_tie.t b/t/03_tie.t
index 7ccf39e..9c66d6c 100644
--- a/t/03_tie.t
+++ b/t/03_tie.t
@@ -28,6 +28,9 @@ my $tmp = tempdir( CLEANUP => 1 );
     is($hash{yay}, 'yappo');
     $hash{foo} = 'baz';
     is($hash{foo}, 'baz');
+    $hash{delete} = 'delete';
+    is(delete $hash{delete}, 'delete');
+    is(delete $hash{delete}, undef);
 
     is(join(" ", sort keys %hash), "foo yay");
     is(join(" ", sort values %hash), "baz yappo");

From 879640f4c5d4e16f755dc77b4548fc149aff263a Mon Sep 17 00:00:00 2001
From: Kenichi Ishigaki <ishigaki@cpan.org>
Date: Thu, 4 Jul 2013 13:40:10 +0900
Subject: [PATCH 4/5] fixed EXISTS

---
 lib/UnQLite.pm | 4 ++--
 t/03_tie.t     | 2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/UnQLite.pm b/lib/UnQLite.pm
index 3868d37..cabfda4 100644
--- a/lib/UnQLite.pm
+++ b/lib/UnQLite.pm
@@ -139,9 +139,9 @@ sub NEXTKEY {
 
 sub EXISTS {
     my ($self, $key) = @_;
-    $self->[1]->kv_fetch($key);
+    $self->[1]->kv_fetch($key) and return 1;
     my $errstr = $self->[1]->errstr;
-    return $errstr eq 'UNQLITE_NOTFOUND' ? 1 : 0;
+    return $errstr && $errstr eq 'UNQLITE_OK' ? 1 : 0;
 }
 
 sub CLEAR {
diff --git a/t/03_tie.t b/t/03_tie.t
index 9c66d6c..4d6d936 100644
--- a/t/03_tie.t
+++ b/t/03_tie.t
@@ -31,6 +31,8 @@ my $tmp = tempdir( CLEANUP => 1 );
     $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");

From 38116a08c5da32cd7950bb57a74a2e35b38e0cd0 Mon Sep 17 00:00:00 2001
From: Kenichi Ishigaki <ishigaki@cpan.org>
Date: Thu, 4 Jul 2013 13:48:22 +0900
Subject: [PATCH 5/5] better use UNQLITE_OK as there may be other errors

---
 lib/UnQLite.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/UnQLite.pm b/lib/UnQLite.pm
index cabfda4..d1ee57c 100644
--- a/lib/UnQLite.pm
+++ b/lib/UnQLite.pm
@@ -120,7 +120,7 @@ sub DELETE {
     my ($self, $key) = @_;
     my $prev = $self->[1]->kv_fetch($key);
     my $errstr = $self->[1]->errstr;
-    return if $errstr && $errstr eq 'UNQLITE_NOTFOUND';
+    return unless $errstr && $errstr eq 'UNQLITE_OK';
     $self->[1]->kv_delete($key) or Carp::croak $self->[1]->errstr;
     $prev;
 }