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[or-cvs] r10500: Oops, forgot a file (libevent-urz/trunk)
Author: Urz
Date: 2007-06-05 05:31:48 -0400 (Tue, 05 Jun 2007)
New Revision: 10500
Added:
libevent-urz/trunk/sa_evbuffer.c
Log:
Oops, forgot a file
Added: libevent-urz/trunk/sa_evbuffer.c
===================================================================
--- libevent-urz/trunk/sa_evbuffer.c (rev 0)
+++ libevent-urz/trunk/sa_evbuffer.c 2007-06-05 09:31:48 UTC (rev 10500)
@@ -0,0 +1,509 @@
+/*
+ * Copyright (c) 2002-2004 Niels Provos <provos@xxxxxxxxxxxxxx>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#ifdef HAVE_STDARG_H
+#include <stdarg.h>
+#endif
+
+#include "event.h"
+#include "event-internal.h"
+
+
+/* prototypes */
+
+void sa_bufferevent_setwatermark(struct sa_bufferevent *, short, size_t, size_t);
+void sa_bufferevent_read_pressure_cb(struct evbuffer *, size_t, size_t, void *);
+
+int del_notifier_status = NOTIFIER_UNINIT;
+int del_notifier[2];
+static struct event evbuffer_del_event;
+
+static void notify() {
+ if(del_notifier_status == NOTIFIER_READY) {
+ write(del_notifier[EVBUFFER_END], ".", 1);
+ del_notifier_status == NOTIFIER_PENDING;
+ }
+}
+
+static void del_cb(int fd, short what, void *arg)
+{
+ struct sa_bufferevent *np;
+ char readdata;
+ ssize_t readlen;
+
+ /* Read data out of socketpair */
+ readlen = read(fd, &readdata, 1);
+
+ /* Set notifier status back to ready */
+ del_notifier_status = NOTIFIER_READY
+
+ /*
+ * Traverse bufev_list.
+ * If a bufferevent with pending read/write events is found,
+ * then we should perform the callbacks required
+ */
+ for (np = bufev_list_head.lh_first; np != NULL; np = np->list_elem.le_next) {
+ if(np->del_read_event_set) {
+ (*np->readcb)(np, np->cbarg);
+ }
+ if(np->del_write_event_set) {
+ (*np->writecb)(np, np->cbarg);
+ }
+ }
+}
+
+/* Code to do setup / initialization of the evbuffer delayed callbacks
+ * Initially copied from ev_signal_init, then modified.
+ */
+void evbuffer_del_init(void)
+{
+ #ifdef WIN32
+ u_long ioarg = 1;
+ #endif
+
+ if(del_notifier_status != NOTIFIER_UNINIT) {
+ return;
+ }
+
+ /* perform list initialization as required by queue.h */
+ LIST_INIT(&bufev_list_head);
+
+ /* create the delayed notifier socketpair */
+ if (socketpair(AF_UNIX, SOCK_STREAM, 0, del_notifier) == -1)
+ event_err(1, "%s: socketpair", __func__);
+
+ FD_CLOSEONEXEC(del_notifier[0]);
+ FD_CLOSEONEXEC(del_notifier[1]);
+
+ /*
+ * sets calls to del_notifier[EVBUFFER_END] to be non-blocking
+ */
+ #ifdef WIN32
+ ioctlsocket(del_notifier[EVBUFFER_END], FIONBIO, &ioarg);
+ /* see http://msdn2.microsoft.com/en-us/library/ms738573.aspx */
+ #else
+ fcntl(del_notifier[EVBUFFER_END], F_SETFL, O_NONBLOCK);
+ #endif
+
+ event_set(&evbuffer_del_event, del_notifier[DISPATCH_END], EV_READ,
+ del_cb, NULL);
+ /* &ev_signal); */
+ /* I can't find any documentation for this, what does it do? */
+ evbuffer_del_event.ev_flags |= EVLIST_INTERNAL;
+
+ del_notifier_status = NOTIFIER_READY;
+}
+
+static int
+sa_bufferevent_add(struct event *ev, int timeout)
+{
+ struct timeval tv, *ptv = NULL;
+
+ if (timeout) {
+ timerclear(&tv);
+ tv.tv_sec = timeout;
+ ptv = &tv;
+ }
+
+ return (event_add(ev, ptv));
+}
+
+/*
+ * This callback is executed when the size of the input buffer changes.
+ * We use it to apply back pressure on the reading side.
+ */
+
+void
+sa_bufferevent_read_pressure_cb(struct evbuffer *buf, size_t old, size_t now,
+ void *arg) {
+ struct sa_bufferevent *bufev = arg;
+ /*
+ * If we are below the watermark then reschedule reading if it's
+ * still enabled.
+ */
+ if (bufev->wm_read.high == 0 || now < bufev->wm_read.high) {
+ evbuffer_setcb(buf, NULL, NULL);
+
+ if (bufev->enabled & EV_READ)
+ sa_bufferevent_add(&bufev->ev_read, bufev->timeout_read);
+ }
+}
+
+static void
+sa_bufferevent_readcb(int fd, short event, void *arg)
+{
+ struct sa_bufferevent *bufev = arg;
+ int res = 0;
+ short what = EVBUFFER_READ;
+ size_t len;
+ int howmuch = -1;
+
+ if (event == EV_TIMEOUT) {
+ what |= EVBUFFER_TIMEOUT;
+ goto error;
+ }
+
+ /*
+ * If we have a high watermark configured then we don't want to
+ * read more data than would make us reach the watermark.
+ */
+ if (bufev->wm_read.high != 0)
+ howmuch = bufev->wm_read.high;
+
+ res = evbuffer_read(bufev->input, fd, howmuch);
+ if (res == -1) {
+ if (errno == EAGAIN || errno == EINTR)
+ goto reschedule;
+ /* error case */
+ what |= EVBUFFER_ERROR;
+ } else if (res == 0) {
+ /* eof case */
+ what |= EVBUFFER_EOF;
+ }
+
+ if (res <= 0)
+ goto error;
+
+ sa_bufferevent_add(&bufev->ev_read, bufev->timeout_read);
+
+ /* See if this callbacks meets the water marks */
+ len = EVBUFFER_LENGTH(bufev->input);
+ if (bufev->wm_read.low != 0 && len < bufev->wm_read.low)
+ return;
+ if (bufev->wm_read.high != 0 && len > bufev->wm_read.high) {
+ struct evbuffer *buf = bufev->input;
+ event_del(&bufev->ev_read);
+
+ /* Now schedule a callback for us */
+ evbuffer_setcb(buf, sa_bufferevent_read_pressure_cb, bufev);
+ return;
+ }
+
+ /* Invoke the user callback - must always be called last */
+ if (bufev->readcb != NULL)
+ (*bufev->readcb)(bufev, bufev->cbarg);
+ return;
+
+ reschedule:
+ sa_bufferevent_add(&bufev->ev_read, bufev->timeout_read);
+ return;
+
+ error:
+ (*bufev->errorcb)(bufev, what, bufev->cbarg);
+}
+
+static void
+sa_bufferevent_writecb(int fd, short event, void *arg)
+{
+ struct sa_bufferevent *bufev = arg;
+ int res = 0;
+ short what = EVBUFFER_WRITE;
+
+ if (event == EV_TIMEOUT) {
+ what |= EVBUFFER_TIMEOUT;
+ goto error;
+ }
+
+ if (EVBUFFER_LENGTH(bufev->output)) {
+ res = evbuffer_write(bufev->output, fd);
+ if (res == -1) {
+#ifndef WIN32
+/*todo. evbuffer uses WriteFile when WIN32 is set. WIN32 system calls do not
+ *set errno. thus this error checking is not portable*/
+ if (errno == EAGAIN ||
+ errno == EINTR ||
+ errno == EINPROGRESS)
+ goto reschedule;
+ /* error case */
+ what |= EVBUFFER_ERROR;
+
+#else
+ goto reschedule;
+#endif
+
+ } else if (res == 0) {
+ /* eof case */
+ what |= EVBUFFER_EOF;
+ }
+ if (res <= 0)
+ goto error;
+ }
+
+ if (EVBUFFER_LENGTH(bufev->output) != 0)
+ sa_bufferevent_add(&bufev->ev_write, bufev->timeout_write);
+
+ /*
+ * Invoke the user callback if our buffer is drained or below the
+ * low watermark.
+ */
+ if (bufev->writecb != NULL &&
+ EVBUFFER_LENGTH(bufev->output) <= bufev->wm_write.low)
+ (*bufev->writecb)(bufev, bufev->cbarg);
+
+ return;
+
+ reschedule:
+ if (EVBUFFER_LENGTH(bufev->output) != 0)
+ sa_bufferevent_add(&bufev->ev_write, bufev->timeout_write);
+ return;
+
+ error:
+ (*bufev->errorcb)(bufev, what, bufev->cbarg);
+}
+
+/*
+ * Create a new buffered event object.
+ *
+ * The read callback is invoked whenever we read new data.
+ * The write callback is invoked whenever the output buffer is drained.
+ * The error callback is invoked on a write/read error or on EOF.
+ *
+ * Both read and write callbacks maybe NULL. The error callback is not
+ * allowed to be NULL and have to be provided always.
+ */
+
+struct sa_bufferevent *
+sa_bufferevent_new(evbuffercb readcb, evbuffercb writecb,
+ everrorcb errorcb, void *cbarg)
+{
+ struct sa_bufferevent *bufev;
+
+ /* Ensure delayed callbacks are set up. */
+ evbuffer_del_init();
+
+ if ((bufev = calloc(1, sizeof(struct sa_bufferevent))) == NULL)
+ return (NULL);
+
+ if ((bufev->input = evbuffer_new()) == NULL) {
+ free(bufev);
+ return (NULL);
+ }
+
+ if ((bufev->output = evbuffer_new()) == NULL) {
+ evbuffer_free(bufev->input);
+ free(bufev);
+ return (NULL);
+ }
+
+ bufev->readcb = readcb;
+ bufev->writecb = writecb;
+ bufev->errorcb = errorcb;
+
+ bufev->cbarg = cbarg;
+
+ /*
+ * Set to EV_WRITE so that using sa_bufferevent_write is going to
+ * trigger a callback. Reading needs to be explicitly enabled
+ * because otherwise no data will be available.
+ */
+ bufev->enabled = EV_WRITE;
+
+ /*
+ * add bufev to the bufev list
+ */
+ LIST_INSERT_HEAD(&bufev_list_head, bufev, list_elem);
+
+ return (bufev);
+}
+
+int
+sa_bufferevent_priority_set(struct sa_bufferevent *bufev, int priority)
+{
+ if (event_priority_set(&bufev->ev_read, priority) == -1)
+ return (-1);
+ if (event_priority_set(&bufev->ev_write, priority) == -1)
+ return (-1);
+
+ return (0);
+}
+
+/* Closing the file descriptor is the responsibility of the caller */
+
+void
+sa_bufferevent_free(struct sa_bufferevent *bufev)
+{
+ struct sa_bufferevent *np;
+
+ evbuffer_free(bufev->input);
+ evbuffer_free(bufev->output);
+
+ /*
+ * Remove from list of bufferevents
+ */
+ for (np = bufev_list_head.lh_first; np != NULL; np = np->list_elem.le_next) {
+ if(np == bufev) {
+ LIST_REMOVE(np, list_elem);
+ break;
+ }
+ }
+
+ free(bufev);
+}
+
+/*
+ * Returns 0 on success;
+ * -1 on failure.
+ */
+
+int
+sa_bufferevent_write(struct sa_bufferevent *bufev, void *data, size_t size)
+{
+ int res;
+
+ res = evbuffer_add(bufev->output, data, size);
+
+ if (res == -1)
+ return (res);
+
+ /* If everything is okay, we need to schedule a write */
+ if (size > 0 && (bufev->enabled & EV_WRITE))
+ sa_bufferevent_add(&bufev->ev_write, bufev->timeout_write);
+
+ return (res);
+}
+
+int
+sa_bufferevent_write_buffer(struct sa_bufferevent *bufev, struct evbuffer *buf)
+{
+ int res;
+
+ res = sa_bufferevent_write(bufev, buf->buffer, buf->off);
+ if (res != -1)
+ evbuffer_drain(buf, buf->off);
+
+ return (res);
+}
+
+size_t
+sa_bufferevent_read(struct sa_bufferevent *bufev, void *data, size_t size)
+{
+ struct evbuffer *buf = bufev->input;
+
+ if (buf->off < size)
+ size = buf->off;
+
+ /* Copy the available data to the user buffer */
+ memcpy(data, buf->buffer, size);
+
+ if (size)
+ evbuffer_drain(buf, size);
+
+ return (size);
+}
+
+int
+sa_bufferevent_enable(struct sa_bufferevent *bufev, short event)
+{
+ if (event & EV_READ) {
+ if (sa_bufferevent_add(&bufev->ev_read, bufev->timeout_read) == -1)
+ return (-1);
+ }
+ if (event & EV_WRITE) {
+ if (sa_bufferevent_add(&bufev->ev_write, bufev->timeout_write) == -1)
+ return (-1);
+ }
+
+ bufev->enabled |= event;
+ return (0);
+}
+
+int
+sa_bufferevent_disable(struct sa_bufferevent *bufev, short event)
+{
+ if (event & EV_READ) {
+ if (event_del(&bufev->ev_read) == -1)
+ return (-1);
+ }
+ if (event & EV_WRITE) {
+ if (event_del(&bufev->ev_write) == -1)
+ return (-1);
+ }
+
+ bufev->enabled &= ~event;
+ return (0);
+}
+
+/*
+ * Sets the read and write timeout for a buffered event.
+ */
+
+void
+sa_bufferevent_settimeout(struct sa_bufferevent *bufev,
+ int timeout_read, int timeout_write) {
+ bufev->timeout_read = timeout_read;
+ bufev->timeout_write = timeout_write;
+}
+
+/*
+ * Sets the water marks
+ */
+
+void
+sa_bufferevent_setwatermark(struct sa_bufferevent *bufev, short events,
+ size_t lowmark, size_t highmark)
+{
+ if (events & EV_READ) {
+ bufev->wm_read.low = lowmark;
+ bufev->wm_read.high = highmark;
+ }
+
+ if (events & EV_WRITE) {
+ bufev->wm_write.low = lowmark;
+ bufev->wm_write.high = highmark;
+ }
+
+ /* If the watermarks changed then see if we should call read again */
+ sa_bufferevent_read_pressure_cb(bufev->input,
+ 0, EVBUFFER_LENGTH(bufev->input), bufev);
+}
+
+int
+sa_bufferevent_base_set(struct event_base *base, struct sa_bufferevent *bufev)
+{
+ int res;
+
+ res = event_base_set(base, &bufev->ev_read);
+ if (res == -1)
+ return (res);
+
+ res = event_base_set(base, &bufev->ev_write);
+ return (res);
+}