--- /dev/null
+/* -*-c-*-
+ *
+ * $Id: pkbuf.h,v 1.1 2000/06/17 10:39:19 mdw Exp $
+ *
+ * Simple packet buffering
+ *
+ * (c) 2000 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of the mLib utilities library.
+ *
+ * mLib is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * mLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Revision history --------------------------------------------------*
+ *
+ * $Log: pkbuf.h,v $
+ * Revision 1.1 2000/06/17 10:39:19 mdw
+ * Experimental new support for packet buffering.
+ *
+ */
+
+#ifndef MLIB_PKBUF_H
+#define MLIB_PKBUF_H
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stddef.h>
+
+#ifndef MLIB_ARENA_H
+# include "arena.h"
+#endif
+
+#ifndef MLIB_BITS_H
+# include "bits.h"
+#endif
+
+/*----- Data structures ---------------------------------------------------*/
+
+typedef struct pkbuf {
+ size_t sz; /* Size of current buffer */
+ size_t len; /* Length of data in the buffer */
+ size_t want; /* Want this many bytes for packet */
+ unsigned f; /* Various state flags */
+ void (*func)(octet */*b*/, size_t /*sz*/,
+ struct pkbuf */*pk*/, size_t */*keep*/,
+ void */*p*/); /* Handler function */
+ void *p; /* Argument for handler */
+ arena *a; /* Memory allocation arena */
+ octet *buf; /* Actual buffer space */
+} pkbuf;
+
+enum {
+ PKBUF_ENABLE = 1 /* Buffer is currently enabled */
+};
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @pkbuf_flush@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @octet *p@ = pointer to where to start searching
+ * @size_t len@ = length of new material added
+ *
+ * Returns: ---
+ *
+ * Use: Flushes any complete packets in a packet buffer. New
+ * material is assumed to have been added starting at @p@. If
+ * @p@ is null, then the scan starts at the beginning of the
+ * buffer, and the size of data already in the buffer is used in
+ * place of @len@.
+ *
+ * It is assumed that the buffer is initially enabled. You
+ * shouldn't be contributing data to a disabled buffer anyway.
+ * However, the buffer handler may at some point disable itself,
+ * and @pkbuf_flush@ can cope with this eventuality. Any
+ * pending data is left at the start of the buffer and can be
+ * flushed out by calling @pkbuf_flush(b, 0, 0)@ if the buffer
+ * is ever re-enabled.
+ */
+
+extern void pkbuf_flush(pkbuf */*pk*/, octet */*p*/, size_t /*len*/);
+
+/* --- @pkbuf_close@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ *
+ * Returns: ---
+ *
+ * Use: Informs the client that no more data is likely to arrive. If
+ * there is a partial packet in the buffer, it is discarded.
+ */
+
+extern void pkbuf_close(pkbuf */*pk*/);
+
+/* --- @pkbuf_free@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @octet **p@ = output pointer to free space
+ *
+ * Returns: Free buffer size.
+ *
+ * Use: Returns the free portion of a packet buffer. Data can then
+ * be written to this portion, and split out into packets by
+ * calling @pkbuf_flush@.
+ */
+
+extern size_t pkbuf_free(pkbuf */*pk*/, octet **/*p*/);
+
+/* --- @pkbuf_snarf@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @const void *p@ = pointer to input data buffer
+ * @size_t sz@ = size of data in input buffer
+ *
+ * Returns: ---
+ *
+ * Use: Snarfs the data from the input buffer and spits it out as
+ * packets. This interface ignores the complexities of dealing
+ * with disablement: you should be using @pkbuf_free@ to
+ * contribute data if you want to cope with that.
+ */
+
+extern void pkbuf_snarf(pkbuf */*pk*/, const void */*p*/, size_t /*sz*/);
+
+/* --- @pkbuf_want@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @size_t want@ = how many octets wanted for next packet
+ *
+ * Returns: ---
+ *
+ * Use: Sets the desired size for the next packet to be read. If
+ * it's larger than the current buffer, the buffer is extended.
+ */
+
+extern void pkbuf_want(pkbuf */*pk*/, size_t /*want*/);
+
+/* --- @pkbuf_init@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ * @void (*func)(octet *b, size_t sz, pkbuf *pk,@
+ * @size_t *keep, void *p)@ =
+ * handler function
+ * @void *p@ = argument pointer for @func@
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a packet buffer block. Any packets are passed to
+ * the provided function for handling.
+ */
+
+extern void pkbuf_init(pkbuf */*pk*/,
+ void (*/*func*/)(octet */*b*/, size_t /*sz*/,
+ pkbuf */*pk*/, size_t */*keep*/,
+ void */*p*/),
+ void */*p*/);
+
+/* --- @pkbuf_destroy@ --- *
+ *
+ * Arguments: @pkbuf *pk@ = pointer to buffer block
+ *
+ * Returns: ---
+ *
+ * Use: Deallocates a packet buffer and frees any resources it owned.
+ */
+
+extern void pkbuf_destroy(pkbuf */*pk*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif
~mdw / mLib / blobdiff