decodemail: use append mode to reduce memory requirements.

* decodemail/decodemail.c (main): Open output mailbox in append mode.
If truncate is requested, open it rw for truncating, then close and
reopen for appending. This speeds up operation considerably.
* libproto/mbox/mbox.c (mbox_open): Change rules for selecting mmap vs
file open.
(mbox_close): Destroy the stream.
(append_message_to_stream): Minor fix.
(mbox_append_message): Unlock the stream on failure as well as on
success.

2 files changed, 86 insertions, 35 deletions

diff --git a/decodemail/decodemail.c b/decodemail/decodemail.c
index b263e1dc1..420309749 100644
--- a/decodemail/decodemail.c
+++ b/decodemail/decodemail.c
@@ -121,6 +121,47 @@ abend (int code)
   exit (code);
 }
 
+static void
+mailbox_truncate (mu_mailbox_t mbox)
+{
+  int rc;
+  mu_iterator_t itr;
+
+  mu_mailbox_get_iterator (mbox, &itr);
+  for (mu_iterator_first (itr); !mu_iterator_is_done (itr);
+       mu_iterator_next (itr))
+    {
+      mu_message_t m;
+      mu_attribute_t a;
+	      
+      if ((rc = mu_iterator_current (itr, (void **)&m)) != 0)
+	{
+	  mu_error (_("can't get current message while truncating the mailbox: %s"),
+		    mu_strerror (rc));
+	  exit (EX_OSERR);
+	}
+      mu_message_get_attribute (m, &a);
+      mu_attribute_set_deleted (a);
+    }
+  mu_iterator_destroy (&itr);
+  if ((rc = mu_mailbox_expunge (mbox)) != 0)
+    {
+      mu_error (_("error expunging destination mailbox: %s"),
+		mu_strerror (rc));
+      exit (EX_OSERR);
+    }
+}
+
+static void
+output_mbox_cleanup (void *arg)
+{
+  if (arg)
+    {
+      mu_mailbox_t mbox = arg;
+      mu_mailbox_unlock (mbox);
+    }
+}
+
 int
 main (int argc, char **argv)
 {
@@ -201,7 +242,31 @@ main (int argc, char **argv)
 		    mu_strerror (rc));
 	  abend (EX_OSERR);
 	}
-      rc = mu_mailbox_open (ombox, MU_STREAM_RDWR|MU_STREAM_CREAT);
+
+      mu_onexit (output_mbox_cleanup, ombox);
+      
+      if (truncate_opt)
+	{
+	  rc = mu_mailbox_open (ombox, MU_STREAM_RDWR);
+	  switch (rc)
+	    {
+	    case 0:
+	      mailbox_truncate (ombox);
+	      mu_mailbox_close (ombox);
+	      break;
+
+	    case ENOENT:
+	    case MU_ERR_NOENT:
+	      break;
+
+	    default:
+	      mu_error (_("could not open mailbox `%s': %s"),
+			ombox_name, mu_strerror (rc));
+	      abend (EX_OSERR);
+	    }
+	}	  
+
+      rc = mu_mailbox_open (ombox, MU_STREAM_APPEND|MU_STREAM_CREAT);
       if (rc)
 	{
 	  mu_error (_("could not open mailbox `%s': %s"),
@@ -214,21 +279,6 @@ main (int argc, char **argv)
 	  strcmp (type, "MBOX") == 0)
 	from_filter = 1;
       
-      if (truncate_opt)
-	{
-	  mu_mailbox_get_iterator (ombox, &itr);
-	  for (mu_iterator_first (itr), i = 1; !mu_iterator_is_done (itr);
-	       mu_iterator_next (itr), i++)
-	    {
-	      mu_message_t m;
-	      mu_attribute_t a;
-	      
-	      rc = mu_iterator_current (itr, (void **)&m);
-	      mu_message_get_attribute (m, &a);
-	      mu_attribute_set_deleted (a);
-	    }
-	  mu_iterator_destroy (&itr);
-	}
       message_store = message_store_mbox;
     }
   else
@@ -272,7 +322,7 @@ main (int argc, char **argv)
   enable_log_prefix (0);
   
   mu_mailbox_destroy (&imbox);
-  (truncate_opt ? mu_mailbox_expunge : mu_mailbox_sync) (ombox);
+  mu_mailbox_sync (ombox);
   mu_mailbox_destroy (&ombox);
 
   if (err)
diff --git a/libproto/mbox/mbox.c b/libproto/mbox/mbox.c
index dad348ce7..d05482ce3 100644
--- a/libproto/mbox/mbox.c
+++ b/libproto/mbox/mbox.c
@@ -83,11 +83,11 @@ mbox_open (mu_mailbox_t mailbox, int flags)
   /* Get a stream.  */
   if (mailbox->stream == NULL)
     {
-      /* We do not try to mmap for CREAT or APPEND, it is not supported.  */
-      status = (flags & MU_STREAM_CREAT)
-	          || (mailbox->flags & MU_STREAM_APPEND);
-
-      /* Try to mmap () the file first.  */
+      /* Prefer mmap, unless the mailbox file does not exist and CREAT is
+	 requested or the mailbox is being opened for appending */
+      status = (((flags & MU_STREAM_CREAT) && access (mud->name, F_OK)) ||
+		(mailbox->flags & MU_STREAM_APPEND));
+      
       if (status == 0)
 	{
 	  status = mu_mapfile_stream_create (&mailbox->stream, mud->name,
@@ -119,7 +119,8 @@ mbox_close (mu_mailbox_t mailbox)
 {
   mbox_data_t mud = mailbox->data;
   size_t i; 
-
+  int rc;
+  
   if (mud == NULL)
     return EINVAL;
 
@@ -160,7 +161,10 @@ mbox_close (mu_mailbox_t mailbox)
   mud->uidnext = 0;
   mu_monitor_unlock (mailbox->monitor);
 
-  return mu_stream_close (mailbox->stream);
+  rc = mu_stream_close (mailbox->stream);
+  if (rc == 0)
+    mu_stream_destroy (&mailbox->stream);
+  return rc;
 }
 
 static int
@@ -1068,14 +1072,12 @@ append_message_to_stream (mu_stream_t ostr, mu_message_t msg,
 
       if (flags & MBOX_FIRSTMSG)
 	{
-	  /* FIXME: Perhaps printf should return error code,
-	     like the rest of stream functions. */
-	  mu_stream_printf (ostr, "%s: %lu %u\n",
-			    MU_HEADER_X_IMAPBASE,
-			    (unsigned long) mud->uidvalidity,
-			    (unsigned) mud->uidnext);
-	  if (mu_stream_err (ostr))
-	    return mu_stream_last_error (ostr);
+	  status = mu_stream_printf (ostr, "%s: %lu %u\n",
+				     MU_HEADER_X_IMAPBASE,
+				     (unsigned long) mud->uidvalidity,
+				     (unsigned) mud->uidnext);
+	  if (status)
+	    return status;
 	}
 
       status = msg_attr_to_stream (ostr, msg);
@@ -1140,9 +1142,8 @@ mbox_append_message (mu_mailbox_t mailbox, mu_message_t msg)
     }
 
   status = mu_stream_seek (mailbox->stream, 0, MU_SEEK_END, &size);
-  if (status)
-    return status;
-  status = append_message_to_stream (mailbox->stream, msg, mud, 0);
+  if (status == 0)
+    status = append_message_to_stream (mailbox->stream, msg, mud, 0);
   if (mailbox->locker)
     mu_locker_unlock (mailbox->locker);