From 66e5de9eaefc33ffa6af3617f9ec7a50f10af50d Mon Sep 17 00:00:00 2001 From: Henrik Rydberg Date: Thu, 17 Jun 2010 18:12:58 +0200 Subject: Initial load of mtdev project Signed-off-by: Henrik Rydberg --- src/iobuf.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 src/iobuf.c (limited to 'src/iobuf.c') diff --git a/src/iobuf.c b/src/iobuf.c new file mode 100644 index 0000000..6d238ec --- /dev/null +++ b/src/iobuf.c @@ -0,0 +1,69 @@ +/***************************************************************************** + * + * mtdev - MT device event converter (MIT license) + * + * Copyright (C) 2010 Henrik Rydberg + * Copyright (C) 2010 Canonical Ltd. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + * + ****************************************************************************/ + +#include "iobuf.h" +#include "state.h" + +int mtdev_fetch(struct mtdev *dev, struct input_event *ev, int fd) +{ + struct mtdev_iobuf *buf = &dev->state->iobuf; + int n = buf->head - buf->tail; + if (n < EVENT_SIZE) { + if (buf->tail && n > 0) + memmove(buf->data, buf->data + buf->tail, n); + buf->head = n; + buf->tail = 0; + SYSCALL(n = read(fd, buf->data + buf->head, + DIM_BUFFER - buf->head)); + if (n <= 0) + return n; + buf->head += n; + } + if (buf->head - buf->tail < EVENT_SIZE) + return 0; + memcpy(ev, buf->data + buf->tail, EVENT_SIZE); + buf->tail += EVENT_SIZE; + return 1; +} + +int mtdev_pull(struct mtdev *dev, int fd, int max_events) +{ + struct mtdev_state *state = dev->state; + struct input_event ev; + int ret, count = 0; + while (max_events-- && !evbuf_full(&state->inbuf)) { + ret = mtdev_fetch(dev, &ev, fd); + if (ret < 0) + return ret; + if (ret == 0) + break; + mtdev_put(dev, &ev); + count++; + } + return count; +} -- cgit v1.2.3