diff options
Diffstat (limited to 'mtdev/iobuf.c')
-rw-r--r-- | mtdev/iobuf.c | 54 |
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; +} |