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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);
+}