Implement mailbox iterators.

* include/mailutils/mailbox.h (mu_mailbox_get_iterator): New function.
* libproto/include/mailbox0.h (struct _mu_mailbox)<iterator>: New
member.
* mailbox/mbxitr.c: New file.
* mailbox/Makefile.am (libmailutils_la_SOURCES): Add mbxitr.c

@@ -107,6 +107,9 @@ extern int  mu_mailbox_get_observable  (mu_mailbox_t, mu_observable_t *);
 /* Locking */  
 extern int mu_mailbox_lock (mu_mailbox_t mbox);
 extern int mu_mailbox_unlock (mu_mailbox_t mbox);
+
+extern int mu_mailbox_get_iterator (mu_mailbox_t mbx,
+				    mu_iterator_t *piterator);
   
 #ifdef __cplusplus
 }

@@ -29,6 +29,7 @@
 
 #include <mailutils/monitor.h>
 #include <mailutils/mailbox.h>
+#include <mailutils/iterator.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -46,7 +47,8 @@ struct _mu_mailbox
   int flags;
   mu_folder_t folder;
   mu_monitor_t monitor;
-
+  mu_iterator_t iterator;
+  
   /* Back pointer to the specific mailbox */
   void *data;
 

@@ -95,6 +95,7 @@ libmailutils_la_SOURCES = \
  mailer.c\
  mapfile_stream.c\
  mbx_default.c\
+ mbxitr.c\
  md5.c\
  message.c\
  memory_stream.c\

+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2010 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library; if not, write to the
+   Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301 USA */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+
+#include <mailutils/debug.h>
+#include <mailutils/errno.h>
+#include <mailutils/error.h>
+#include <mailutils/iterator.h>
+
+#include <mailbox0.h>
+
+struct mailbox_iterator
+{
+  mu_mailbox_t mbx;
+  size_t idx;
+};
+
+static int
+mbx_first (void *owner)
+{
+  struct mailbox_iterator *itr = owner;
+  itr->idx = 1;
+  return 0;
+}
+
+static int
+mbx_next (void *owner)
+{
+  struct mailbox_iterator *itr = owner;
+  itr->idx++;
+  return 0;
+}
+
+static int
+mbx_getitem (void *owner, void **pret, const void **pkey)
+{
+  struct mailbox_iterator *itr = owner;
+  size_t count;
+  int rc;
+  
+  rc = mu_mailbox_messages_count (itr->mbx, &count);
+  if (rc)
+    return rc;
+  if (itr->idx > count)
+    return MU_ERR_NOENT;
+  rc = mu_mailbox_get_message (itr->mbx, itr->idx, (mu_message_t*)pret);
+  if (rc == 0 && pkey)
+    *pkey = NULL; /* FIXME: Perhaps return UIDL or other unique id? */
+  return rc;
+}
+
+static int
+mbx_finished_p (void *owner)
+{
+  struct mailbox_iterator *itr = owner;
+  size_t count;
+
+  if (mu_mailbox_messages_count (itr->mbx, &count))
+    return 1;
+  return itr->idx > count;
+}
+
+static int
+mbx_destroy (mu_iterator_t iterator, void *data)
+{
+  struct mailbox_iterator *itr = data;
+
+  mu_iterator_detach (&itr->mbx->iterator, iterator);
+  free (data);
+  return 0;
+}
+
+static int
+mbx_curitem_p (void *owner, void *item)
+{
+  void *ptr;
+
+  if (mbx_getitem (owner, &ptr, NULL))
+    return 0;
+  return ptr == item;/* FIXME: Is it ok? */
+}
+
+static int
+mbx_data_dup (void **ptr, void *owner)
+{
+  struct mailbox_iterator *itr = owner;
+
+  *ptr = malloc (sizeof (struct mailbox_iterator));
+  if (*ptr == NULL)
+    return ENOMEM;
+  memcpy (*ptr, owner, sizeof (struct mailbox_iterator));
+  mu_iterator_attach (&itr->mbx->iterator, *ptr);
+  return 0;
+}
+
+int
+mu_mailbox_get_iterator (mu_mailbox_t mbx, mu_iterator_t *piterator)
+{
+  mu_iterator_t iterator;
+  int status;
+  struct mailbox_iterator *itr;
+
+  if (!mbx)
+    return EINVAL;
+
+  itr = calloc (1, sizeof *itr);
+  if (!itr)
+    return ENOMEM;
+  itr->mbx = mbx;
+  itr->idx = 1;
+
+  status = mu_iterator_create (&iterator, itr);
+  if (status)
+    {
+      free (itr);
+      return status;
+    }
+
+  mu_iterator_set_first (iterator, mbx_first);
+  mu_iterator_set_next (iterator, mbx_next);
+  mu_iterator_set_getitem (iterator, mbx_getitem);
+  mu_iterator_set_finished_p (iterator, mbx_finished_p);
+  mu_iterator_set_curitem_p (iterator, mbx_curitem_p);
+  mu_iterator_set_destroy (iterator, mbx_destroy);
+  mu_iterator_set_dup (iterator, mbx_data_dup);
+
+  mu_iterator_attach (&mbx->iterator, iterator);
+
+  *piterator = iterator;
+  return 0;
+}
+
+
+
+
+
+  
+