2004-11-04 Andrew J. Schorr <ajschorr@alumni.princeton.edu>

	* vty.c: Vtysh connections to daemons should use buffering.
	  (vty_out) Remove exception for vty_shell_serv, just use buffer_write.
	  (vty_new) Increase output buffer size to 4096 rounded up to a
	  multiple of pagesize.
	  (vtysh_read) After command has been executed and all output buffered,
	  call buffer_flush_available and schedule further writes if the
	  buffers are not yet empty.
	  (vtysh_write) New function to flush output to vtysh when the socket
	  is writeable.
	  (vty_event) Added new VTYSH_WRITE event for flushing buffers to vtysh
	  clients.  Also, should save read thread in vty->t_read so the
	  thread can be cancelled in vty_close.
	* buffer.h: In struct buffer_data, remove unused "parent" field.
	  Convert "unsigned char *data" to "unsigned char data[0]" to save
	  a malloc.  Declare new function buffer_flush_available that works
	  with non-blocking sockets.
	* buffer.c: (buffer_data_new) Use a single malloc now that data is
	  a variable-size array at end of structure.
	  (buffer_data_free) Just a single free now that data is part of the
	  structure.
	  (buffer_write) Simplify the logic to make behavior more transparent.
	  (buffer_flush) Decrease b->length as data is written out.
	  (buffer_flush_vty_all) Decrease b->length as buffers are freed.
	  (buffer_flush_vty) Decrease b->length as data is written out.
	  (buffer_flush_available) New function to flush non-blocking sockets.

1 files changed, 11 insertions, 5 deletions

diff --git a/lib/buffer.h b/lib/buffer.h
index 9d453b1d06..2acd571fde 100644
--- a/lib/buffer.h
+++ b/lib/buffer.h
@@ -33,7 +33,7 @@ struct buffer
   /* Current allocated data. */
   unsigned long alloc;
 
-  /* Total length of buffer. */
+  /* Size of each buffer_data chunk. */
   unsigned long size;
 
   /* For allocation. */
@@ -47,18 +47,17 @@ struct buffer
 /* Data container. */
 struct buffer_data
 {
-  struct buffer *parent;
   struct buffer_data *next;
   struct buffer_data *prev;
 
-  /* Acctual data stream. */
-  unsigned char *data;
-
   /* Current pointer. */
   unsigned long cp;
 
   /* Start pointer. */
   unsigned long sp;
+
+  /* Actual data stream (variable length). */
+  unsigned char data[0];  /* real dimension is buffer->size */
 };
 
 /* Buffer prototypes. */
@@ -74,4 +73,11 @@ int buffer_flush_vty_all (struct buffer *, int, int, int);
 int buffer_flush_window (struct buffer *, int, int, int, int, int);
 int buffer_empty (struct buffer *);
 
+/* buffer_flush_available attempts to flush the queued data to the given
+   file descriptor.  It returns 0 if the buffers are now empty (after
+   flushing), or 1 if more data remains on the buffer queue (must be flushed
+   later).  This function (unlike the other buffer_flush* functions) is
+   designed to work with non-blocking file descriptors. */
+int buffer_flush_available(struct buffer *, int fd);
+
 #endif /* _ZEBRA_BUFFER_H */