Provide a function for quick retrieval of message lines.

* include/mailutils/message.h (mu_message_quick_lines): New proto.
(mu_message_set_lines): Change signature of the 2nd argument.
* include/mailutils/sys/message.h (_mu_message) <lines>: Change
signature.
* libmailutils/diag/errors (MU_ERR_INFO_UNAVAILABLE): New error code.
* libmailutils/mailbox/message.c (mu_message_set_lines): Change
signature of the 2nd argument.
(mu_message_lines): Update call to the _lines method.
(mu_message_quick_lines): New function.
* libproto/pop/mbox.c (_POP3_MSG_LINES): New flag.
(_pop3_message)<message_lines>: New member.
(pop_create_pop3_message): New function.
(pop_scan): Use LIST to obtain scan listing.
(pop_message_lines): New function.
(pop_create_message): Set _lines method.
(pop_get_message): Use pop_create_pop3_message.

* mail/from.c (hdr_quick_lines): New function.
(compile_headline): New escape %L

* pop3d/capa.c (pop3d_capa): Show XLINES capability if
configured.
* pop3d/list.c (pop3d_list): Optionally output the number of
lines in the message.
* pop3d/pop3d.c (pop3d_xlines): New global.
(pop3d_cfg_param): New statement "scan-lines".
* pop3d/pop3d.h (pop3d_xlines): New extern.

@@ -97,8 +97,9 @@ extern int mu_message_set_size (mu_message_t,
 				void *owner);
 
 extern int mu_message_lines (mu_message_t, size_t *);
+extern int mu_message_quick_lines (mu_message_t, size_t *);
 extern int mu_message_set_lines (mu_message_t, 
-				 int (*_lines) (mu_message_t, size_t *),
+				 int (*_lines) (mu_message_t, size_t *, int),
 				 void *owner);
 
 extern int mu_message_get_num_parts (mu_message_t, size_t *nparts);

@@ -58,7 +58,7 @@ struct _mu_message
   int (*_get_num_parts)  (mu_message_t, size_t *);
   int (*_get_part)       (mu_message_t, size_t, mu_message_t *);
   int (*_is_multipart)   (mu_message_t, int *);
-  int (*_lines)          (mu_message_t, size_t *);
+  int (*_lines)          (mu_message_t, size_t *, int);
   int (*_size)           (mu_message_t, size_t *);
 };
 

@@ -95,3 +95,5 @@ MU_ERR_AUTH_NO_CRED         _("No credentials supplied")
 
 MU_ERR_URL_MISS_PARTS       _("URL missing required parts")
 MU_ERR_URL_EXTRA_PARTS      _("URL has parts not allowed by its scheme")
+
+MU_ERR_INFO_UNAVAILABLE	    _("Information is not yet available")

@@ -882,7 +882,7 @@ mu_message_set_get_stream (mu_message_t msg,
 
 int
 mu_message_set_lines (mu_message_t msg, int (*_lines)
-		   (mu_message_t, size_t *), void *owner)
+		      (mu_message_t, size_t *, int), void *owner)
 {
   if (msg == NULL)
     return EINVAL;
@@ -902,7 +902,7 @@ mu_message_lines (mu_message_t msg, size_t *plines)
     return EINVAL;
   /* Overload.  */
   if (msg->_lines)
-    return msg->_lines (msg, plines);
+    return msg->_lines (msg, plines, 0);
   if (plines)
     {
       hlines = blines = 0;
@@ -913,6 +913,36 @@ mu_message_lines (mu_message_t msg, size_t *plines)
   return ret;
 }
 
+/* Return the number of lines in the message, without going into
+   excess trouble for calculating it.  If obtaining the result
+   means downloading the entire message (as is the case for POP3,
+   for example), return MU_ERR_INFO_UNAVAILABLE. */
+int
+mu_message_quick_lines (mu_message_t msg, size_t *plines)
+{
+  size_t hlines, blines;
+  int rc;
+  
+  if (msg == NULL)
+    return EINVAL;
+  /* Overload.  */
+  if (msg->_lines)
+    {
+      int rc = msg->_lines (msg, plines, 1);
+      if (rc != ENOSYS)
+	return rc;
+    }
+  if (plines)
+    {
+      hlines = blines = 0;
+      if ((rc = mu_header_lines (msg->header, &hlines)) == 0)
+	rc = mu_body_lines (msg->body, &blines);
+      if (rc == 0)
+	*plines = hlines + blines;
+    }
+  return rc;
+}
+
 int
 mu_message_set_size (mu_message_t msg, int (*_size)
 		  (mu_message_t, size_t *), void *owner)

@@ -60,6 +60,7 @@
 #define _POP3_MSG_SIZE    0x02      /* Message size obtained */
 #define _POP3_MSG_SCANNED 0x04      /* Message has been scanned */
 #define _POP3_MSG_ATTRSET 0x08      /* Attributes has been set */
+#define _POP3_MSG_LINES   0x10      /* Number of lines was obtained */
 
 struct _pop3_message
 {
@@ -70,7 +71,8 @@ struct _pop3_message
   size_t header_lines;      /* Number of lines in the header */
   size_t body_lines;        /* Number of lines in the body */
   int attr_flags;           /* Message attributes */
-  size_t message_size;      /* Message size */ 
+  size_t message_size;      /* Message size */
+  size_t message_lines;     /* Number of lines in the message */
   size_t num;               /* Message number */
   char *uidl;               /* Cached uidl string.  */
   mu_message_t message;     /* Pointer to the message structure */ 
@@ -95,6 +97,9 @@ struct _pop3_mailbox
   mu_secret_t secret;
 };
 
+static int pop_create_pop3_message (struct _pop3_mailbox *mpd, size_t msgno,
+				    struct _pop3_message **mptr);
+
 
 /* ------------------------------------------------------------------------- */
 /* Basic operations */
@@ -270,34 +275,89 @@ pop_messages_count (mu_mailbox_t mbox, size_t *pcount)
     }
   return status;
 }
-  
+
 static int
 pop_scan (mu_mailbox_t mbox, size_t msgno, size_t *pcount)
 {
   int status;
   size_t i;
   size_t count = 0;
-
+  struct _pop3_mailbox *mpd = mbox->data;
+  int flags;
+  mu_iterator_t itr;
+  
   status = pop_messages_count (mbox, &count);
   if (status != 0)
     return status;
   if (pcount)
     *pcount = count;
-  if (mbox->observable == NULL)
-    return 0;
-  for (i = msgno; i <= count; i++)
+
+  flags = _POP3_MSG_SIZE;
+  if (!mu_pop3_capa_test (mpd->pop3, "XLINES", NULL))
+    flags |= _POP3_MSG_LINES;
+
+  status = mu_pop3_list_all (mpd->pop3, &itr);
+  if (status)
+    return status;
+  
+  for (i = 0, mu_iterator_first (itr);
+       i <= count && !mu_iterator_is_done (itr);
+       i++, mu_iterator_next (itr))
     {
-      size_t tmp = i;
-      if (mu_observable_notify (mbox->observable, MU_EVT_MESSAGE_ADD,
-				&tmp) != 0)
-	break;
-      if (((i + 1) % 10) == 0)
+      const char *str;
+      char *p;
+      size_t num;
+      
+      mu_iterator_current (itr, (void**) &str);
+      num = strtoul (str, &p, 10);
+
+      if (*p != ' ')
 	{
-	  mu_observable_notify (mbox->observable, MU_EVT_MAILBOX_PROGRESS,
-				NULL);
+	  mu_debug (MU_DEBCAT_MAILBOX, MU_DEBUG_ERROR,
+		    ("invalid reply to LIST command: %s", str));
+	  status = MU_ERR_BADREPLY;
+	  break;
+	}
+      if (num >= msgno)
+	{
+	  size_t size, lines;
+	  struct _pop3_message *mpm;
+
+	  size = strtoul (p + 1, &p, 10);
+	  if (flags & _POP3_MSG_LINES)
+	    {
+	      if (*p != ' ')
+		{
+		  mu_debug (MU_DEBCAT_MAILBOX, MU_DEBUG_ERROR,
+			    ("invalid reply to LIST command: %s", str));
+		  status = MU_ERR_BADREPLY;
+		  break;
+		}
+	      lines = strtoul (p + 1, &p, 10);
+	    }
+
+	  status = pop_create_pop3_message (mpd, num, &mpm);
+	  if (status)
+	    break;
+	  mpm->message_size = size;
+	  if (flags & _POP3_MSG_LINES)
+	    mpm->message_lines = lines;
+	  mpm->flags |= flags;
+
+	  if (mbox->observable)
+	    {
+	      if (mu_observable_notify (mbox->observable, MU_EVT_MESSAGE_ADD,
+					&num) != 0)
+		break;
+	      if (((i + 1) % 10) == 0)
+		mu_observable_notify (mbox->observable,
+				      MU_EVT_MAILBOX_PROGRESS,
+				      NULL);
+	    }
 	}
     }
-  return 0;
+  mu_iterator_destroy (&itr);
+  return status;
 }
 
 /* There's no way to retrieve this info via POP3 */
@@ -475,6 +535,29 @@ pop_message_size (mu_message_t msg, size_t *psize)
 }
 
 static int
+pop_message_lines (mu_message_t msg, size_t *plines, int quick)
+{
+  int rc;
+  struct _pop3_message *mpm = mu_message_get_owner (msg);
+
+  if (!(mpm->flags & _POP3_MSG_LINES))
+    {
+      if (quick && !(mpm->flags & _POP3_MSG_CACHED))
+	return MU_ERR_INFO_UNAVAILABLE;
+      if (!pop_is_updated (mpm->mpd->mbox))
+	pop_scan (mpm->mpd->mbox, 1, NULL);
+      rc = pop_scan_message (mpm);
+      if (rc)
+	return rc;
+      mpm->message_lines = mpm->header_lines + mpm->body_lines + 1;
+      mpm->flags |= _POP3_MSG_LINES;
+    }
+
+  *plines = mpm->message_lines;
+  return 0;
+}
+
+static int
 pop_create_message (struct _pop3_message *mpm, struct _pop3_mailbox *mpd)
 {
   int status;
@@ -486,10 +569,47 @@ pop_create_message (struct _pop3_message *mpm, struct _pop3_mailbox *mpd)
 
   mu_message_set_get_stream (msg, pop_message_get_stream, mpm);
   mu_message_set_size (msg, pop_message_size, mpm);
+  mu_message_set_lines (msg, pop_message_lines, mpm);
   mpm->message = msg;
   return 0;
 }
 
+static int
+pop_create_pop3_message (struct _pop3_mailbox *mpd, size_t msgno,
+			 struct _pop3_message **mptr)
+{
+  int status;
+  struct _pop3_message *mpm;
+  
+  if (msgno > mpd->msg_count)
+    return EINVAL;
+
+  if (!mpd->msg)
+    {
+      mpd->msg = calloc (mpd->msg_count, sizeof (mpd->msg[0]));
+      if (!mpd->msg)
+	return ENOMEM;
+    }
+  if (mpd->msg[msgno - 1])
+    {
+      *mptr = mpd->msg[msgno - 1];
+      return 0;
+    }
+
+  mpm = calloc (1, sizeof (*mpm));
+  if (mpm == NULL)
+    return ENOMEM;
+
+  /* Back pointer.  */
+  mpm->mpd = mpd;
+  mpm->num = msgno;
+  
+  mpd->msg[msgno - 1] = mpm;
+  *mptr = mpm;
+  return status;
+}
+
+
 
 /* ------------------------------------------------------------------------- */
 /* Header */
@@ -798,36 +918,19 @@ pop_get_message (mu_mailbox_t mbox, size_t msgno, mu_message_t *pmsg)
   if (!pop_is_updated (mbox))
     pop_scan (mbox, 1, NULL);
 
-  if (msgno > mpd->msg_count)
-    return EINVAL;
-
-  if (!mpd->msg)
-    {
-      mpd->msg = calloc (mpd->msg_count, sizeof (mpd->msg[0]));
-      if (!mpd->msg)
-	return ENOMEM;
-    }
-  if (mpd->msg[msgno - 1])
+  status = pop_create_pop3_message (mpd, msgno, &mpm);
+  if (status)
+    return status;
+  if (mpm->message)
     {
-      *pmsg = mpd->msg[msgno - 1]->message;
+      *pmsg = mpm->message;
       return 0;
     }
 
-  mpm = calloc (1, sizeof (*mpm));
-  if (mpm == NULL)
-    return ENOMEM;
-
-  /* Back pointer.  */
-  mpm->mpd = mpd;
-  mpm->num = msgno;
-  
   status = pop_create_message (mpm, mpd);
   if (status)
-    {
-      free (mpm);
-      return status;
-    }
-
+    return status;
+  
   do
     {
       status = pop_create_header (mpm);
@@ -852,7 +955,6 @@ pop_get_message (mu_mailbox_t mbox, size_t msgno, mu_message_t *pmsg)
 
   mu_message_set_uid (mpm->message, pop_uid, mpm);
 
-  mpd->msg[msgno - 1] = mpm;
   mu_message_set_mailbox (mpm->message, mbox, mpm);
   *pmsg = mpm->message;
   return 0;

@@ -294,11 +294,29 @@ hdr_lines (struct header_call_args *args, void *data)
 {
   size_t m_lines;
   char buf[UINTMAX_STRSIZE_BOUND];
+
   mu_message_lines (args->msg, &m_lines);
   
   return header_buf_string (args, umaxtostr (m_lines, buf));
 }
 
+/* %L */
+static char *
+hdr_quick_lines (struct header_call_args *args, void *data)
+{
+  size_t m_lines;
+  char buf[UINTMAX_STRSIZE_BOUND];
+  int rc;
+  const char *p;
+  
+  rc = mu_message_quick_lines (args->msg, &m_lines);
+  if (rc == 0)
+    p = umaxtostr (m_lines, buf);
+  else
+    p = "NA";
+  return header_buf_string (args, p);
+}
+
 /* %m */
 static char *
 hdr_number (struct header_call_args *args, void *data)
@@ -466,6 +484,11 @@ compile_headline (const char *str)
 	case 'l': /* The number of lines of the message */
 	  seg = new_header_segment (ALIGN_NUMBER, width, NULL, hdr_lines);
 	  break;
+
+	case 'L': /* Same, but in quick mode */
+	  seg = new_header_segment (ALIGN_NUMBER, width, NULL,
+				    hdr_quick_lines);
+	  break;
 	  
 	case 'm': /* Message number */
 	  seg = new_header_segment (ALIGN_NUMBER, width, NULL, hdr_number);

@@ -38,7 +38,9 @@ pop3d_capa (char *arg)
   pop3d_outf ("UIDL\n");
   pop3d_outf ("RESP-CODES\n");
   pop3d_outf ("PIPELINING\n");
-
+  if (pop3d_xlines)
+    pop3d_outf ("XLINES\n");
+    
 #ifdef WITH_TLS
   if (tls_available && tls_done == 0)
     pop3d_outf ("STLS\n");

@@ -17,8 +17,27 @@
 
 #include "pop3d.h"
 
-/* Displays the size of message number arg or all messages (if no arg) */
-
+/* From RFC 1939:
+   
+   In order to simplify parsing, all POP3 servers are
+   required to use a certain format for scan listings.  A
+   scan listing consists of the message-number of the
+   message, followed by a single space and the exact size of
+   the message in octets.  Methods for calculating the exact
+   size of the message are described in the "Message Format"
+   section below.  This memo makes no requirement on what
+   follows the message size in the scan listing.  Minimal
+   implementations should just end that line of the response
+   with a CRLF pair.  More advanced implementations may
+   include other information, as parsed from the message.
+   <end of quote>
+   
+  GNU pop3d uses this allowance and includes in the scan
+  listing the number of lines in message.  This optional
+  feature is enabled by setting "scan-lines yes" in the
+  configuration file.  When on, it is indicated by the
+  XLINES capability.
+*/
 int
 pop3d_list (char *arg)
 {
@@ -47,9 +66,12 @@ pop3d_list (char *arg)
 	    {
 	      mu_message_size (msg, &size);
 	      mu_message_lines (msg, &lines);
-	      pop3d_outf ("%s %s\n", 
+	      pop3d_outf ("%s %s", 
                           mu_umaxtostr (0, mesgno), 
                           mu_umaxtostr (1, size + lines));
+	      if (pop3d_xlines)
+		pop3d_outf (" %s", mu_umaxtostr (2, lines));
+	      pop3d_outf ("\n");
 	    }
 	}
       pop3d_outf (".\n");
@@ -64,10 +86,14 @@ pop3d_list (char *arg)
 	return ERR_MESG_DELE;
       mu_message_size (msg, &size);
       mu_message_lines (msg, &lines);
-      pop3d_outf ("+OK %s %s\n", 
+      pop3d_outf ("+OK %s %s", 
                   mu_umaxtostr (0, mesgno),
                   mu_umaxtostr (1, size + lines));
+      if (pop3d_xlines)
+	pop3d_outf (" %s", mu_umaxtostr (2, lines));
+      pop3d_outf ("\n");
     }
 
   return OK;
 }
+

@@ -30,6 +30,7 @@ unsigned int idle_timeout;
 int pop3d_transcript;
 int debug_mode;
 int tls_required;
+int pop3d_xlines;
 
 #ifdef WITH_TLS
 int tls_available;
@@ -95,6 +96,8 @@ static struct mu_cfg_param pop3d_cfg_param[] = {
     N_("days") },
   { "delete-expired", mu_cfg_bool, &expire_on_exit, 0, NULL,
     N_("Delete expired messages upon closing the mailbox.") },
+  { "scan-lines", mu_cfg_bool, &pop3d_xlines, 0, NULL,
+    N_("Output the number of lines in the message in its scan listing.") },
 #ifdef WITH_TLS
   { "tls-required", mu_cfg_bool, &tls_required, 0, NULL,
      N_("Always require STLS before entering authentication phase.") },

@@ -196,6 +196,7 @@ extern struct mu_auth_data *auth_data;
 extern unsigned int idle_timeout;
 extern int pop3d_transcript;
 extern size_t pop3d_output_bufsize;
+extern int pop3d_xlines;
 
 extern pop3d_command_handler_t pop3d_find_command (const char *name);
 

@@ -59,3 +59,4 @@ pop3d_stat (char *arg)
 
   return OK;
 }
+