gatchat: Add initial GAtIO implementation

1 files changed, 265 insertions, 0 deletions

diff --git a/gatchat/gatio.c b/gatchat/gatio.c
new file mode 100644
index 00000000..964bc057
--- /dev/null
+++ b/gatchat/gatio.c
@@ -0,0 +1,265 @@
+/*
+ *
+ *  AT chat library with GLib integration
+ *
+ *  Copyright (C) 2008-2010  Intel Corporation. All rights reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <assert.h>
+#include <ctype.h>
+#include <errno.h>
+
+#include <glib.h>
+
+#include "ringbuffer.h"
+#include "gatio.h"
+#include "gatutil.h"
+
+struct _GAtIO {
+	gint ref_count;				/* Ref count */
+	guint read_watch;			/* GSource read id, 0 if no */
+	GIOChannel *channel;			/* comms channel */
+	GAtDisconnectFunc user_disconnect;	/* user disconnect func */
+	gpointer user_disconnect_data;		/* user disconnect data */
+	struct ring_buffer *buf;		/* Current read buffer */
+	guint max_read_attempts;		/* max reads / select */
+	GAtIOReadFunc read_handler;		/* Read callback */
+	gpointer read_data;			/* Read callback userdata */
+	GAtDebugFunc debugf;			/* debugging output function */
+	gpointer debug_data;			/* Data to pass to debug func */
+	gboolean destroyed;			/* Re-entrancy guard */
+};
+
+static void read_watcher_destroy_notify(gpointer user_data)
+{
+	GAtIO *io = user_data;
+
+	ring_buffer_free(io->buf);
+	io->buf = NULL;
+
+	io->channel = NULL;
+	io->read_watch = 0;
+
+	if (io->user_disconnect)
+		io->user_disconnect(io->user_disconnect_data);
+
+	if (io->destroyed)
+		g_free(io);
+}
+
+static gboolean received_data(GIOChannel *channel, GIOCondition cond,
+				gpointer data)
+{
+	unsigned char *buf;
+	GAtIO *io = data;
+	GIOError err;
+	gsize rbytes;
+	gsize toread;
+	gsize total_read = 0;
+	guint read_count = 0;
+
+	if (cond & G_IO_NVAL)
+		return FALSE;
+
+	/* Regardless of condition, try to read all the data available */
+	do {
+		toread = ring_buffer_avail_no_wrap(io->buf);
+
+		if (toread == 0)
+			break;
+
+		rbytes = 0;
+		buf = ring_buffer_write_ptr(io->buf, 0);
+
+		err = g_io_channel_read(channel, (char *) buf, toread, &rbytes);
+		g_at_util_debug_chat(TRUE, (char *)buf, rbytes,
+					io->debugf, io->debug_data);
+
+		read_count++;
+
+		total_read += rbytes;
+
+		if (rbytes > 0)
+			ring_buffer_write_advance(io->buf, rbytes);
+
+	} while (err == G_IO_ERROR_NONE && rbytes > 0 &&
+					read_count < io->max_read_attempts);
+
+	if (total_read > 0 && io->read_handler)
+		io->read_handler(io->buf, io->read_data);
+
+	if (cond & (G_IO_HUP | G_IO_ERR))
+		return FALSE;
+
+	if (read_count > 0 && rbytes == 0 && err != G_IO_ERROR_AGAIN)
+		return FALSE;
+
+	return TRUE;
+}
+
+static GAtIO *create_io(GIOChannel *channel, GIOFlags flags)
+{
+	GAtIO *io;
+
+	if (!channel)
+		return NULL;
+
+	io = g_try_new0(GAtIO, 1);
+	if (!io)
+		return io;
+
+	io->ref_count = 1;
+	io->debugf = NULL;
+
+	if (flags & G_IO_FLAG_NONBLOCK)
+		io->max_read_attempts = 3;
+	else
+		io->max_read_attempts = 1;
+
+	io->buf = ring_buffer_new(4096);
+
+	if (!io->buf)
+		goto error;
+
+	if (!g_at_util_setup_io(channel, flags))
+		goto error;
+
+	io->channel = channel;
+	io->read_watch = g_io_add_watch_full(channel, G_PRIORITY_DEFAULT,
+				G_IO_IN | G_IO_HUP | G_IO_ERR | G_IO_NVAL,
+				received_data, io,
+				read_watcher_destroy_notify);
+
+	return io;
+
+error:
+	if (io->buf)
+		ring_buffer_free(io->buf);
+
+	g_free(io);
+
+	return NULL;
+}
+
+GAtIO *g_at_io_new(GIOChannel *channel)
+{
+	return create_io(channel, G_IO_FLAG_NONBLOCK);
+}
+
+GAtIO *g_at_io_new_blocking(GIOChannel *channel)
+{
+	return create_io(channel, 0);
+}
+
+GIOChannel *g_at_io_get_channel(GAtIO *io)
+{
+	if (io == NULL)
+		return NULL;
+
+	return io->channel;
+}
+
+gboolean g_at_io_set_read_handler(GAtIO *io, GAtIOReadFunc read_handler,
+					gpointer user_data)
+{
+	if (io == NULL)
+		return FALSE;
+
+	io->read_handler = read_handler;
+	io->read_data = user_data;
+
+	if (read_handler && ring_buffer_len(io->buf) > 0)
+		read_handler(io->buf, user_data);
+
+	return TRUE;
+}
+
+GAtIO *g_at_io_ref(GAtIO *io)
+{
+	if (io == NULL)
+		return NULL;
+
+	g_atomic_int_inc(&io->ref_count);
+
+	return io;
+}
+
+void g_at_io_unref(GAtIO *io)
+{
+	gboolean is_zero;
+
+	if (io == NULL)
+		return;
+
+	is_zero = g_atomic_int_dec_and_test(&io->ref_count);
+
+	if (is_zero == FALSE)
+		return;
+
+	g_at_io_shutdown(io);
+
+	/* glib delays the destruction of the watcher until it exits, this
+	 * means we can't free the data just yet, even though we've been
+	 * destroyed already.  We have to wait until the read_watcher
+	 * destroy function gets called
+	 */
+	if (io->read_watch != 0)
+		io->destroyed = TRUE;
+	else
+		g_free(io);
+}
+
+gboolean g_at_io_shutdown(GAtIO *io)
+{
+	if (io->channel == NULL)
+		return FALSE;
+
+	if (io->read_watch)
+		g_source_remove(io->read_watch);
+
+	return TRUE;
+}
+
+gboolean g_at_io_set_disconnect_function(GAtIO *io,
+			GAtDisconnectFunc disconnect, gpointer user_data)
+{
+	if (io == NULL)
+		return FALSE;
+
+	io->user_disconnect = disconnect;
+	io->user_disconnect_data = user_data;
+
+	return TRUE;
+}
+
+gboolean g_at_io_set_debug(GAtIO *io, GAtDebugFunc func, gpointer user_data)
+{
+	if (io == NULL)
+		return FALSE;
+
+	io->debugf = func;
+	io->debug_data = user_data;
+
+	return TRUE;
+}