1 files changed, 54 insertions, 0 deletions

diff --git a/mtdev/iobuf.c b/mtdev/iobuf.c
new file mode 100644
index 0000000..8e367b8
--- /dev/null
+++ b/mtdev/iobuf.c
@@ -0,0 +1,54 @@
+/***************************************************************************
+ *
+ * Multitouch X driver
+ * Copyright (C) 2008 Henrik Rydberg <rydberg@euromail.se>
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ **************************************************************************/
+
+#include <mtdev-iobuf.h>
+
+void init_iobuf(struct IOBuffer *buf)
+{
+        memset(buf, 0, sizeof(struct IOBuffer));
+        buf->at = buf->begin;
+        buf->top = buf->at;
+        buf->end = buf->begin + DIM_BUFFER;
+}
+
+const struct input_event *get_iobuf_event(struct IOBuffer *buf, int fd)
+{
+        const struct input_event *ev;
+        int n = buf->top - buf->at;
+        if (n < EVENT_SIZE) {
+                /* partial event is available: save it */
+                if (buf->at != buf->begin && n > 0)
+                        memmove(buf->begin, buf->at, n);
+                /* start from the beginning */
+                buf->at = buf->begin;
+                buf->top = buf->at + n;
+                /* read more data */
+                SYSCALL(n = read(fd, buf->top, buf->end - buf->top));
+                if (n <= 0)
+                        return NULL;
+                buf->top += n;
+        }
+        if (buf->top - buf->at < EVENT_SIZE)
+                return NULL;
+        ev = (const struct input_event *)buf->at;
+        buf->at += EVENT_SIZE;
+        return ev;
+}