Rewrite folder listing interface.

New function mu_folder_scan provides an improved scanning interface.
In particular, it allows the user to abridge the scan to mailboxes
of certain type (or types).

Existing listing API functions are rewritten as alternative entry
points to mu_folder_scan.

* include/mailutils/folder.h (mu_folder_scanner): New struct.
(mu_folder_scan): New function.
* include/mailutils/registrar.h (mu_registrar_list_p): New function.
* include/mailutils/sys/folder.h (_mu_folder._list): Change
signature.
* libmailutils/base/registrar.c (mu_registrar_list_p): New function.
* libmailutils/mailbox/folder.c (mu_folder_scan): New function.
(mu_folder_enumerate): Rewrite as entry point to mu_folder_scan.
* libmailutils/mailbox/fsfolder.c: Use new API,
* libmailutils/tests/fsfolder.c: Rewrite scheme matcher.
* libmailutils/tests/fsfolder00.at: Fix test output.
* libmailutils/tests/fsfolder02.at: Likewise.
* libproto/imap/folder.c: Use new API.

10 files changed, 194 insertions, 104 deletions

diff --git a/include/mailutils/folder.h b/include/mailutils/folder.h
index 12327987d..4ca4b92ee 100644
--- a/include/mailutils/folder.h
+++ b/include/mailutils/folder.h
@@ -51,18 +51,42 @@ extern int  mu_folder_delete         (mu_folder_t, const char *);
 extern int  mu_folder_rename         (mu_folder_t, const char *, const char *);
 extern int  mu_folder_subscribe      (mu_folder_t, const char *);
 extern int  mu_folder_unsubscribe    (mu_folder_t, const char *);
-extern int  mu_folder_list           (mu_folder_t, const char *, void *,
-                                      size_t, mu_list_t *);
-extern int  mu_folder_enumerate      (mu_folder_t, const char *,
-                                      void *, int, 
-                                      size_t, mu_list_t *,
-                                      mu_folder_enumerate_fp, void *);
 extern int  mu_folder_lsub           (mu_folder_t, const char *, const char *,
                                       mu_list_t *);
 
 extern int mu_folder_attach_ticket (mu_folder_t folder);
 extern int mu_folder_is_local (mu_folder_t folder);
 
+  /* Scan API */
+/* The mu_folder_scanner structure controls the scanning. All of
+   members are optional. Unused ones must be initialized to 0.
+*/
+struct mu_folder_scanner
+{
+  char const *refname;     /* Reference name */
+  void *pattern;           /* Matching pattern */
+  int match_flags;         /* Matching flags */
+  size_t max_level;        /* Max. nesting level to descend */
+  mu_folder_enumerate_fp enumfun; /* Enumeration function */
+  void *enumdata;                 /* Data for enumfun */
+  mu_list_t records;        /* List of allowed records */
+  mu_list_t result;         /* Result list */
+};
+
+#define MU_FOLDER_SCANNER_INITIALIZER \
+  { NULL, NULL, 0, 0, NULL, NULL, NULL, NULL }
+  
+int mu_folder_scan (mu_folder_t folder, struct mu_folder_scanner *scn);
+
+/* The following two functions are implemented as alternative entry
+   points to mu_folder_scan: */
+extern int  mu_folder_list           (mu_folder_t, const char *, void *,
+                                      size_t, mu_list_t *);
+extern int  mu_folder_enumerate      (mu_folder_t, const char *,
+                                      void *, int, 
+                                      size_t, mu_list_t *,
+                                      mu_folder_enumerate_fp, void *);
+    
   /* Match function */
 extern int mu_folder_set_match (mu_folder_t folder, mu_folder_match_fp pmatch);
 extern int mu_folder_get_match (mu_folder_t folder,
diff --git a/include/mailutils/registrar.h b/include/mailutils/registrar.h
index 976e82190..a2cd76b0b 100644
--- a/include/mailutils/registrar.h
+++ b/include/mailutils/registrar.h
@@ -93,6 +93,7 @@ int mu_record_get_mailer      (mu_record_t, int (*(*)) (mu_mailer_t));
 int mu_record_get_folder      (mu_record_t, int (*(*)) (mu_folder_t));
   
 int mu_record_list_p (mu_record_t record, const char *name, int);
+int mu_registrar_list_p (mu_list_t rlist, char const *name, int flags);
   
 /* Records provided by the library.  */
 
diff --git a/include/mailutils/sys/folder.h b/include/mailutils/sys/folder.h
index 050a18f97..6dd2d45da 100644
--- a/include/mailutils/sys/folder.h
+++ b/include/mailutils/sys/folder.h
@@ -49,8 +49,7 @@ struct _mu_folder
 
   int  (*_open)        (mu_folder_t, int flag);
   int  (*_close)       (mu_folder_t);
-  int  (*_list)        (mu_folder_t, const char *, void *, int, size_t,
-                        mu_list_t, mu_folder_enumerate_fp, void *);
+  int  (*_list)        (mu_folder_t, struct mu_folder_scanner *);
   int  (*_lsub)        (mu_folder_t, const char *, const char *,
                         mu_list_t);
   mu_folder_match_fp   _match;
diff --git a/libmailutils/base/registrar.c b/libmailutils/base/registrar.c
index da736a07f..e25e6d810 100644
--- a/libmailutils/base/registrar.c
+++ b/libmailutils/base/registrar.c
@@ -400,6 +400,29 @@ mu_registrar_test_local_url (mu_url_t url, int *pres)
   return 0;
 }
 
+struct listable_closure
+{
+  char const *name;
+  int flags;
+};
+
+static int
+record_listable (void *item, void *data)
+{
+  mu_record_t record = item;
+  struct listable_closure *cls = data;
+  return !mu_record_list_p (record, cls->name, cls->flags);
+}
+
+int
+mu_registrar_list_p (mu_list_t rlist, char const *name, int flags)
+{
+  struct listable_closure cls = { name, flags };
+  if (!rlist)
+    rlist = registrar_list;
+  return !mu_list_foreach (rlist, record_listable, &cls);
+}       
+
 /* Apply flt to each record in the registry and remove those, for which it
    returns non-zero. */
 int
diff --git a/libmailutils/mailbox/folder.c b/libmailutils/mailbox/folder.c
index 9df89ed05..8a474c8f6 100644
--- a/libmailutils/mailbox/folder.c
+++ b/libmailutils/mailbox/folder.c
@@ -343,6 +343,18 @@ mu_list_response_free (void *data)
 }
 
 int
+mu_folder_scan (mu_folder_t folder, struct mu_folder_scanner *scn)
+{
+  if (!folder || !scn)
+    return EINVAL;
+  if (folder->_list == NULL)
+    return ENOSYS;
+  if (scn->result)
+    mu_list_set_destroy_item (scn->result, mu_list_response_free);
+  return folder->_list (folder, scn);
+}
+
+int
 mu_folder_list (mu_folder_t folder, const char *dirname, void *pattern,
                 size_t max_level,
                 mu_list_t *pflist)
@@ -360,29 +372,35 @@ mu_folder_enumerate (mu_folder_t folder, const char *name,
                      mu_folder_enumerate_fp enumfun, void *enumdata)
 {
   int status;
-  if (folder == NULL)
+  if (folder == NULL || (!pflist && !enumfun))
     return EINVAL;
   else if (folder->_list == NULL)
     return ENOSYS;
   else
     {
-      mu_list_t list = NULL;
-      
+      struct mu_folder_scanner scn;
+
+      scn.refname = name;
+      scn.pattern = pattern;
+      scn.match_flags = flags;
+      scn.max_level = max_level;
+      scn.enumfun = enumfun;
+      scn.enumdata = enumdata;
+      scn.records = NULL;
       if (pflist)
         {
-          status = mu_list_create (&list);
+          status = mu_list_create (&scn.result);
           if (status)
             return status;
-          *pflist = list;
-          mu_list_set_destroy_item (list, mu_list_response_free);
         }
-      else if (!enumfun)
-        return EINVAL;
-      
-      status = folder->_list (folder, name, pattern, flags, max_level,
-                              list, enumfun, enumdata);
-      if (status)
-        mu_list_destroy (pflist);
+      status = mu_folder_scan (folder, &scn);
+      if (status == 0)
+        {
+          if (pflist)
+            *pflist = scn.result;
+        }
+      else
+        mu_list_destroy (&scn.result);
     }
   return status;
 }
diff --git a/libmailutils/mailbox/fsfolder.c b/libmailutils/mailbox/fsfolder.c
index 2b8aa2e99..042ae6707 100644
--- a/libmailutils/mailbox/fsfolder.c
+++ b/libmailutils/mailbox/fsfolder.c
@@ -183,18 +183,12 @@ struct inode_list           /* Inode/dev number list used to cut off
   dev_t dev;
 };