empserver/src/lib/gen/ioqueue.c

455 lines
9.5 KiB
C

/*
* Empire - A multi-player, client/server Internet based war game.
* Copyright (C) 1986-2000, Dave Pare, Jeff Bailey, Thomas Ruschak,
* Ken Stevens, Steve McClure
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* ---
*
* See the "LEGAL", "LICENSE", "CREDITS" and "README" files for all the
* related information and legal notices. It is expected that any future
* projects/authors will amend these files as needed.
*
* ---
*
* ioqueue.c: Read and write i/o queues
*
* Known contributors to this file:
*
*/
/*
* Read and write onto io queues. Note that
* the io queues don't actually do any writing;
* that is left for a higher level.
*/
#include <stdio.h>
#include <stdlib.h> /* malloc free */
#include <sys/types.h>
#if !defined(_WIN32)
#include <sys/uio.h>
#endif
#include "misc.h"
#include "queue.h"
#include "ioqueue.h"
static int ioqtocbuf(struct ioqueue *ioq, s_char *buf, int cc,
register int stopc);
#if !defined(_WIN32)
static int ioqtoiov(struct ioqueue *ioq, struct iovec *iov,
register int max);
#endif
static int ioqtobuf(struct ioqueue *ioq, s_char *buf, int cc);
static int appendcc(struct ioqueue *ioq, s_char *buf, int cc);
static int removecc(struct ioqueue *ioq, register int cc);
#if defined(_WIN32)
static void loc_StripDels(char *pBuf);
#endif
struct ioqueue *
ioq_create(int size)
{
struct ioqueue *ioq;
ioq = (struct ioqueue *)malloc(sizeof(struct ioqueue));
emp_initque(&ioq->list.queue);
ioq->list.nbytes = 0;
ioq->list.offset = 0;
ioq->list.size = 0;
ioq->list.data = 0;
ioq->bufsize = size;
ioq->cc = 0;
return ioq;
}
void
ioq_destroy(struct ioqueue *ioq)
{
#if !defined(aix) && !defined(NeXT)
/* ioq_drain doesn't work under aix or NeXT... dunno why --ts */
ioq_drain(ioq);
#endif /* aix */
free((s_char *)ioq);
}
void
ioq_drain(struct ioqueue *ioq)
{
struct emp_qelem *qp;
struct io *io;
while ((qp = ioq->list.queue.q_forw) != &ioq->list.queue) {
io = (struct io *)qp;
(void)emp_remque(&io->queue);
(void)free((s_char *)io->data);
(void)free((s_char *)io);
}
ioq->cc = 0;
}
/*
* copy batch of pointers into the passed
* iovec, but don't actually dequeue the data.
* return # of iovec initialized.
*/
#if !defined(_WIN32)
int
ioq_makeiov(struct ioqueue *ioq, struct iovec *iov, int cc)
{
if (ioq->cc <= 0)
return 0;
return ioqtoiov(ioq, iov, cc);
}
#endif
/*
* Copy the specified number of characters into the buffer
* provided, without actually dequeueing the data. Return
* number of bytes actually found.
*/
int
ioq_peek(struct ioqueue *ioq, s_char *buf, int cc)
{
return ioqtobuf(ioq, buf, cc);
}
int
ioq_dequeue(struct ioqueue *ioq, int cc)
{
return removecc(ioq, cc);
}
void
ioq_append(struct ioqueue *ioq, s_char *buf, int cc)
{
appendcc(ioq, buf, cc);
}
int
ioq_qsize(struct ioqueue *ioq)
{
return ioq->cc;
}
/*
* read a line of text up to (but not including)
* the newline. return -1 and read nothing if
* no input is available
*/
int
ioq_gets(struct ioqueue *ioq, s_char *buf, int cc)
{
int nbytes;
int actual;
nbytes = ioqtocbuf(ioq, buf, cc - 1, '\n');
if (nbytes >= 0) {
actual = nbytes;
if (actual > cc - 1)
actual = cc - 1;
buf[actual] = '\0';
/* remove the newline too */
removecc(ioq, nbytes + 1);
#if defined(_WIN32)
loc_StripDels(buf);
#endif
}
return nbytes;
}
int
ioq_puts(struct ioqueue *ioq, s_char *buf)
{
return appendcc(ioq, buf, strlen(buf));
}
/*
* all the rest are local to this module
*/
/*
* copy cc bytes from ioq to buf.
* this routine doesn't free memory; this is
* left for a higher level.
*/
static
int
ioqtobuf(struct ioqueue *ioq, s_char *buf, int cc)
{
struct io *io;
struct emp_qelem *qp;
struct emp_qelem *head;
register int nbytes;
register int nleft;
register s_char *offset;
nleft = cc;
offset = buf;
head = &ioq->list.queue;
for (qp = head->q_forw; qp != head && nleft > 0; qp = qp->q_forw) {
io = (struct io *)qp;
if ((nbytes = io->nbytes - io->offset) < 0) {
/* XXX log something here */
continue;
}
if (nbytes > 0) {
if (nleft < nbytes)
nbytes = nleft;
bcopy(io->data + io->offset, offset, nbytes);
offset += nbytes;
nleft -= nbytes;
}
}
return offset - buf;
}
/*
* copy at most cc bytes from ioq to buf,
* terminating on the stop character.
*/
static
int
ioqtocbuf(struct ioqueue *ioq, s_char *buf, int cc, register int stopc)
{
register int nbytes;
register s_char *p;
register int n;
struct io *io;
struct emp_qelem *qp;
struct emp_qelem *head;
int total;
int found;
head = &ioq->list.queue;
found = 0;
total = 0;
for (qp = head->q_forw; qp != head; qp = qp->q_forw) {
io = (struct io *)qp;
if ((nbytes = io->nbytes - io->offset) <= 0)
continue;
p = io->data + io->offset;
for (n = 0; n < nbytes && p[n] != stopc; n++) ;
total += n;
if (n < nbytes) {
found++;
break;
}
}
if (found == 0)
return -1;
ioqtobuf(ioq, buf, cc < total ? cc : total);
return total;
}
/*
* initialize an iovec to point at max bytes worth
* of data from the ioqueue.
*/
#if !defined(_WIN32)
static
int
ioqtoiov(struct ioqueue *ioq, struct iovec *iov, register int max)
{
struct io *io;
register int cc;
register int niov;
register int len;
struct emp_qelem *qp;
cc = max;
niov = 0;
qp = ioq->list.queue.q_forw;
while (qp != &ioq->list.queue && cc > 0) {
io = (struct io *)qp;
len = io->nbytes - io->offset;
if (len > cc)
len = cc;
iov->iov_base = io->data + io->offset;
iov->iov_len = len;
cc -= len;
niov++;
iov++;
qp = qp->q_forw;
if (niov >= 16)
break;
}
return niov;
}
#endif
/*
* append a buffer to the end of the ioq.
*/
static
int
appendcc(struct ioqueue *ioq, s_char *buf, int cc)
{
struct io *io;
int len;
s_char *ptr;
int avail;
/* determine if any space is left */
io = (struct io *)ioq->list.queue.q_back;
avail = io->size - io->nbytes;
if (avail > 0) {
/* append to existing buffer */
len = cc > avail ? avail : cc;
bcopy(buf, io->data + io->nbytes, len);
io->nbytes += len;
ioq->cc += len;
if (avail < cc)
appendcc(ioq, buf + len, cc - len);
} else {
/* create a new buffer, minimum bufsize bytes */
len = cc > ioq->bufsize ? cc : ioq->bufsize;
ptr = malloc(len);
bcopy(buf, ptr, cc);
io = (struct io *)malloc(sizeof(struct io));
io->nbytes = cc;
io->size = len;
io->offset = 0;
io->data = ptr;
emp_insque(&io->queue, ioq->list.queue.q_back);
ioq->cc += cc;
}
return cc;
}
/*
* remove cc bytes from ioqueue ioq
* free memory, dequeue io elements
* which are no longer used.
*/
static
int
removecc(struct ioqueue *ioq, register int cc)
{
struct io *io;
struct emp_qelem *qp;
register int nbytes;
register int there;
register int remain;
nbytes = 0;
remain = cc;
while ((qp = ioq->list.queue.q_forw) != &ioq->list.queue) {
io = (struct io *)qp;
there = io->nbytes - io->offset;
if (there < 0) {
/* error */
(void)emp_remque(&io->queue);
(void)free((s_char *)io);
continue;
}
if (remain >= there) {
/* not enough or exact; free entry */
nbytes += there;
remain -= there;
(void)emp_remque(&io->queue);
(void)free(io->data);
(void)free((s_char *)io);
} else {
/* too much; increment offset */
io->offset += remain;
nbytes += remain;
remain = 0;
}
if (remain <= 0)
break;
}
ioq->cc -= nbytes;
return nbytes;
}
#if defined(_WIN32)
/*
* Make an (output) buffer up to the
* maximum size of the buffer.
*
* We don't free the bytes...
*/
int
ioq_makebuf(struct ioqueue *ioq, char *pBuf, int nBufLen)
{
struct io *io;
struct emp_qelem *qp;
struct emp_qelem *head;
int nbytes;
int nleft;
int ncopied;
s_char *offset;
ncopied = 0;
nleft = nBufLen;
offset = pBuf;
head = &ioq->list.queue;
for (qp = head->q_forw; (qp != head) && (nleft > 0); qp = qp->q_forw) {
io = (struct io *)qp;
nbytes = io->nbytes - io->offset;
if (nbytes < 0) {
/* Paranoid check for bad buffer. */
continue;
}
/* too many bytes, wait till next time. */
if (nbytes > nleft)
break;
bcopy(io->data + io->offset, offset, nbytes);
offset += nbytes;
nleft -= nbytes;
ncopied += nbytes;
}
return ncopied;
}
#endif /* _WIN32 */
#if defined(_WIN32)
/*
* Remove backspaces and DELs from the buffer.
*
* Why? Because I got tired of telneting into the
* server and having to type perfectly...
*/
static void
loc_StripDels(char *pBuf)
{
char *cp;
char *dp;
char *sp;
for (cp = pBuf; *cp;) {
/* Remove Backspace and DEL */
if (*cp == '\b' || *cp == '\x8F') {
if (cp == pBuf)
dp = cp;
else
dp = cp - 1;
sp = cp + 1;
while (*sp)
*dp++ = *sp++;
*dp = 0;
} else
cp++;
}
}
#endif