+++ /dev/null
-/* -*-c-*-
- *
- * 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.
- */
-
-/*----- Header files ------------------------------------------------------*/
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include "alloc.h"
-#include "arena.h"
-#include "pkbuf.h"
-
-/*----- Main code ---------------------------------------------------------*/
-
-/* --- @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.
- */
-
-void pkbuf_flush(pkbuf *pk, octet *p, size_t len)
-{
- size_t l;
- size_t o, keep;
-
- if (pk->f & PKBUF_CLOSE) {
- pk->func(0, 0, pk, 0, pk->p);
- return;
- }
-
- /* --- Initialize variables as necessary --- */
-
- if (!p) {
- p = pk->buf;
- len = pk->len;
- }
- l = p + len - pk->buf;
- o = 0;
-
- /* --- Now grind through any packets which have accumulated --- */
-
- pk->len = l;
- while (l >= pk->want) {
- size_t sz = pk->want;
-
- /* --- Pass a packet to the user handler --- */
-
- keep = 0;
- pk->func(pk->buf + o, sz, pk, &keep, pk->p);
-
- /* --- Adjust all the pointers for the next packet --- */
-
- sz -= keep;
- o += sz;
- l -= sz;
-
- /* --- Abort here if disabled --- */
-
- if (!(pk->f & PKBUF_ENABLE))
- break;
- }
-
- /* --- Shunt data around in the buffer --- */
-
- if (o > 0 && l != 0)
- memmove(pk->buf, pk->buf + o, l);
- pk->len = l;
-}
-
-/* --- @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.
- */
-
-void pkbuf_close(pkbuf *pk)
-{
- if (pk->buf) {
- x_free(pk->a, pk->buf);
- pk->buf = 0;
- }
- pk->f |= PKBUF_CLOSE;
- if (pk->f & PKBUF_ENABLE)
- pk->func(0, 0, pk, 0, pk->p);
-}
-
-/* --- @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@. A buffer is allocated if none
- * currently exists.
- */
-
-size_t pkbuf_free(pkbuf *pk, octet **p)
-{
- if (!pk->buf)
- pk->buf = x_alloc(pk->a, pk->sz);
- *p = pk->buf + pk->len;
- return (pk->sz - pk->len);
-}
-
-/* --- @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.
- */
-
-void pkbuf_snarf(pkbuf *pk, const void *p, size_t sz)
-{
- const octet *pp = p;
- while (sz && (pk->f & PKBUF_ENABLE)) {
- size_t bsz;
- octet *bp;
-
- bsz = pkbuf_free(pk, &bp);
- if (bsz > sz)
- bsz = sz;
- memcpy(bp, pp, bsz);
- pkbuf_flush(pk, bp, bsz);
- pp += bsz;
- sz -= bsz;
- }
-}
-
-/* --- @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.
- */
-
-void pkbuf_want(pkbuf *pk, size_t want)
-{
- pk->want = want;
- if (want > pk->sz) {
- do pk->sz <<= 1; while (want > pk->sz);
- if (pk->buf) {
- if (pk->len)
- pk->buf = x_realloc(pk->a, pk->buf, pk->sz, pk->len);
- else {
- x_free(pk->a, pk->buf);
- pk->buf = 0;
- }
- }
- }
-}
-
-/* --- @pkbuf_init@ --- *
- *
- * Arguments: @pkbuf *pk@ = pointer to buffer block
- * @pkbuf *func@ = 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.
- */
-
-void pkbuf_init(pkbuf *pk, pkbuf_func *func, void *p)
-{
- pk->func = func;
- pk->p = p;
- pk->len = 0;
- pk->f = PKBUF_ENABLE;
- pk->buf = 0;
- pk->sz = 256;
- pk->want = 1;
- pk->a = arena_global;
-}
-
-/* --- @pkbuf_destroy@ --- *
- *
- * Arguments: @pkbuf *pk@ = pointer to buffer block
- *
- * Returns: ---
- *
- * Use: Deallocates a line buffer and frees any resources it owned.
- */
-
-void pkbuf_destroy(pkbuf *pk)
-{
- if (pk->buf) {
- x_free(pk->a, pk->buf);
- pk->buf = 0;
- }
-}
-
-/*----- That's all, folks -------------------------------------------------*/
~mdw / mLib / blobdiff