Optimize stream seeks and I/O. Expand stream event handlers. Rewrite xscript stream.

* include/mailutils/sys/stream.h (_MU_STR_EVENT_SET): Rename
to _MU_STR_EVENT_SET.
(_MU_STR_EVENT_CLR): Rename to _MU_STR_EVENT_CLRFLAG.
(_MU_STR_EVENT_FILLBUF, _MU_STR_EVENT_FLUSHBUF): New event codes.
(_MU_STR_EVMASK): New macro.
(_mu_stream) <cur>: Replace with pos, indicating current position
in the buffer.
(event_cb): Change signature.
(mu_stream_read_unbuffered): Remove.
(mu_stream_write_unbuffered): Remove.

* mailbox/iostream.c (mu_iostream_create): Provide the readdelim method
only if the underlying input transpor stream provides it.
* mailbox/streamref.c (mu_streamref_create_abridged): Likewise.

* mailbox/stream.c (_stream_event): New macro.
(mu_stream_read_unbuffered): Rename to static _stream_read_unbuffered.
(mu_stream_write_unbuffered): Rename to static _stream_write_unbuffered.
(_stream_advance_buffer, _stream_buffer_offset)
(_stream_orig_level): Remove macros.
(_stream_buffer_freespace): Rewrite.
(_stream_curp): New macro.
(_stream_fill_buffer): Make sure the `offset' indicates the offset
int the transport, corresponding to the beginning of the current
buffer.
(_stream_flush_buffer): Essentially rewritten.
(mu_stream_seek): Reflect changes to the _mu_stream structure. Optimize
calls to the seek method.
(_stream_skip_input_bytes): Likewise.
(mu_stream_read, _stream_scandelim, mu_stream_write): Rewrite using
new _mu_stream structure.

* mailbox/xscript-stream.c: Rewrite using stream events.

* mailbox/base64.c (_base64_encoder): Bugfix.

* libproto/pop/pop3_stream.c (_pop3_event_cb): Update signature to
match the changes above.
* examples/mimetest.c (main): Add more error checking.
* mail/testsuite/mail/write.exp: Minor fix.

@@ -116,7 +116,7 @@ main (int argc, char **argv)
   MU_ASSERT (mu_mailbox_open (mbox, MU_STREAM_RDWR));
 
   /* Iterate through the entire message set.  */
-  mu_mailbox_messages_count (mbox, &count);
+  MU_ASSERT (mu_mailbox_messages_count (mbox, &count));
 
   for (i = 1; i <= count; ++i)
     {

@@ -24,8 +24,12 @@
 
 #define _MU_STR_INTERN_MASK   0xf0000000
 
-#define _MU_STR_EVENT_SET     1
-#define _MU_STR_EVENT_CLR     2
+#define _MU_STR_EVENT_SETFLAG   0
+#define _MU_STR_EVENT_CLRFLAG   1
+#define _MU_STR_EVENT_FILLBUF   2
+#define _MU_STR_EVENT_FLUSHBUF  3
+
+#define _MU_STR_EVMASK(n) (1<<(n))
 
 struct _mu_stream
 {
@@ -35,7 +39,7 @@ struct _mu_stream
   size_t bufsize;
   char *buffer;
   size_t level;
-  char *cur;
+  size_t pos;
 
   int flags;
   mu_off_t offset;
@@ -57,7 +61,7 @@ struct _mu_stream
   int (*truncate) (struct _mu_stream *, mu_off_t);
   int (*shutdown) (struct _mu_stream *, int);
 
-  void (*event_cb) (struct _mu_stream *, int, int);
+  void (*event_cb) (struct _mu_stream *, int code, unsigned long, void *);
   int  event_mask;
   
   const char *(*error_string) (struct _mu_stream *, int);
@@ -65,11 +69,6 @@ struct _mu_stream
 };
 
 mu_stream_t _mu_stream_create (size_t size, int flags);
-int mu_stream_read_unbuffered (mu_stream_t stream, void *buf, size_t size,
-			       int full_read, size_t *pnread);
-int mu_stream_write_unbuffered (mu_stream_t stream,
-				const void *buf, size_t size,
-				int full_write, size_t *pnwritten);
 
 void _mu_stream_cleareof (mu_stream_t str);
 void _mu_stream_seteof (mu_stream_t str);

@@ -41,10 +41,12 @@ struct mu_pop3_stream
   struct mu_buffer_query oldbuf;
 };
 
+/* Called on _MU_STR_EVENT_SETFLAG */
 static void
-_pop3_event_cb (mu_stream_t str, int ev, int flags)
+_pop3_event_cb (mu_stream_t str, int ev, unsigned long flags,
+		void *ptr MU_ARG_UNUSED)
 {
-  if (ev == _MU_STR_EVENT_SET)
+  if (flags & _MU_STR_EOF)
     {
       mu_transport_t trans[2];
 
@@ -78,7 +80,7 @@ mu_pop3_filter_create (mu_stream_t *pstream, mu_stream_t stream)
       mu_stream_t str = *pstream;
       
       str->event_cb = _pop3_event_cb;
-      str->event_mask = _MU_STR_EOF;
+      str->event_mask = _MU_STR_EVMASK(_MU_STR_EVENT_SETFLAG);
 
       sp->oldbuf.type = MU_TRANSPORT_OUTPUT;
       if (mu_stream_ioctl (sp->pop3->carrier, MU_IOCTL_GET_TRANSPORT_BUFFER,

@@ -27,7 +27,7 @@ mail_test -noprompt "quit" \
 # Start again using the same mailbox
 mail_start -reuse-spool "--file=%mbox1"
 # Go to the last message and do delete 4 times
-mail_command "4"
+mail_command "3"
 mail_command "delete"
 mail_command "delete"
 mail_command "delete"

@@ -244,6 +244,9 @@ _base64_encoder (void *xd MU_ARG_UNUSED,
       pad = 0;
     }
 
+  /* Consumed may grow bigger than isize if cmd is mu_filter_lastbuf */
+  if (consumed > iobuf->isize)
+    consumed = iobuf->isize;
   iobuf->isize = consumed;
   iobuf->osize = nbytes;
   return mu_filter_ok;

@@ -236,7 +236,8 @@ mu_iostream_create (mu_stream_t *pref, mu_stream_t in, mu_stream_t out)
     return ENOMEM;
 
   sp->stream.read = _iostream_read; 
-  sp->stream.readdelim = _iostream_readdelim; 
+  if (in->readdelim)
+    sp->stream.readdelim = _iostream_readdelim; 
   sp->stream.write = _iostream_write;
   sp->stream.flush = _iostream_flush;
   sp->stream.open = _iostream_open; 

@@ -279,7 +279,8 @@ mu_streamref_create_abridged (mu_stream_t *pref, mu_stream_t str,
   mu_stream_ref (str);
 
   sp->stream.read = _streamref_read; 
-  sp->stream.readdelim = _streamref_readdelim; 
+  if (str->readdelim)
+    sp->stream.readdelim = _streamref_readdelim; 
   sp->stream.write = _streamref_write;
   sp->stream.flush = _streamref_flush;
   sp->stream.open = _streamref_open; 

@@ -167,21 +167,28 @@ print_transcript (struct _mu_xscript_stream *str, int flag,
     }
 }
 
-static int
-_xscript_read (struct _mu_stream *str, char *buf, size_t bufsize,
-	       size_t *pnread)
+static void
+_xscript_event_cb (mu_stream_t str, int ev, unsigned long size, void *ptr)
 {
   struct _mu_xscript_stream *sp = (struct _mu_xscript_stream *)str;
-  size_t nbytes;
-  int rc = mu_stream_read (sp->transport, buf, bufsize, &nbytes);
 
-  if (rc == 0)
+  switch (ev)
     {
-      print_transcript (sp, TRANS_READ, buf, nbytes);
-      if (pnread)
-	*pnread = nbytes;
+    case _MU_STR_EVENT_FILLBUF:
+      print_transcript (sp, TRANS_READ, ptr, size);
+      break;
+
+    case _MU_STR_EVENT_FLUSHBUF:
+      print_transcript (sp, TRANS_WRITE, ptr, size);
     }
-  return rc;
+}
+
+static int
+_xscript_read (struct _mu_stream *str, char *buf, size_t bufsize,
+	       size_t *pnread)
+{
+  struct _mu_xscript_stream *sp = (struct _mu_xscript_stream *)str;
+  return mu_stream_read (sp->transport, buf, bufsize, pnread);
 }
 
 static int
@@ -189,15 +196,7 @@ _xscript_readdelim (struct _mu_stream *str, char *buf, size_t bufsize,
 		    int delim, size_t *pnread)
 {
   struct _mu_xscript_stream *sp = (struct _mu_xscript_stream *)str;
-  size_t nread;
-  int rc = mu_stream_readdelim (sp->transport, buf, bufsize, delim, &nread);
-  if (rc == 0)
-    {
-      print_transcript (sp, TRANS_READ, buf, nread);
-      if (pnread)
-	*pnread = nread;
-    }
-  return rc;
+  return mu_stream_readdelim (sp->transport, buf, bufsize, delim, pnread);
 }
 
 static int
@@ -205,11 +204,7 @@ _xscript_write (struct _mu_stream *str, const char *buf, size_t bufsize,
 		  size_t *pnwrite)
 {
   struct _mu_xscript_stream *sp = (struct _mu_xscript_stream *)str;
-  int rc = mu_stream_write (sp->transport, buf, bufsize, pnwrite);
-
-  if (rc == 0)
-    print_transcript (sp, TRANS_WRITE, buf, pnwrite ? *pnwrite : bufsize);
-  return rc;
+  return mu_stream_write (sp->transport, buf, bufsize, pnwrite);
 }
 
 static int
@@ -318,7 +313,6 @@ _xscript_ctl (struct _mu_stream *str, int op, void *arg)
     case MU_IOCTL_GET_TRANSPORT_BUFFER:
     case MU_IOCTL_SET_TRANSPORT_BUFFER:
       {
-        struct mu_transport_buffer_query *qp = arg;
         if (!sp->transport)
           return EINVAL;
         return mu_stream_ioctl (sp->transport, op, arg);
@@ -391,7 +385,8 @@ mu_xscript_stream_create(mu_stream_t *pref, mu_stream_t transport,
     return ENOMEM;
 
   sp->stream.read = _xscript_read; 
-  sp->stream.readdelim = _xscript_readdelim; 
+  if (transport->readdelim)
+    sp->stream.readdelim = _xscript_readdelim; 
   sp->stream.write = _xscript_write;
   sp->stream.flush = _xscript_flush;
   sp->stream.open = _xscript_open; 
@@ -404,7 +399,9 @@ mu_xscript_stream_create(mu_stream_t *pref, mu_stream_t transport,
   sp->stream.truncate = _xscript_truncate;
   sp->stream.shutdown = _xscript_shutdown;
   sp->stream.error_string = _xscript_error_string;
-
+  sp->stream.event_cb = _xscript_event_cb;
+  sp->stream.event_mask = _MU_STR_EVMASK(_MU_STR_EVENT_FILLBUF) |
+                          _MU_STR_EVMASK(_MU_STR_EVENT_FLUSHBUF);
   if (!(flags & MU_STREAM_AUTOCLOSE))
     {
       mu_stream_ref (transport);