373 lines
9.2 KiB
C
373 lines
9.2 KiB
C
/*
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* File : ringbuffer.c
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* This file is part of RT-Thread RTOS
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* COPYRIGHT (C) 2012, RT-Thread Development Team
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Change Logs:
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* Date Author Notes
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* 2012-09-30 Bernard first version.
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* 2013-05-08 Grissiom reimplement
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* 2016-08-18 heyuanjie add interface
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*/
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#include <rtthread.h>
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#include <rtdevice.h>
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#include <string.h>
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rt_inline enum rt_ringbuffer_state rt_ringbuffer_status(struct rt_ringbuffer *rb)
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{
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if (rb->read_index == rb->write_index)
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{
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if (rb->read_mirror == rb->write_mirror)
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return RT_RINGBUFFER_EMPTY;
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else
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return RT_RINGBUFFER_FULL;
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}
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return RT_RINGBUFFER_HALFFULL;
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}
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void rt_ringbuffer_init(struct rt_ringbuffer *rb,
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rt_uint8_t *pool,
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rt_int16_t size)
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{
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RT_ASSERT(rb != RT_NULL);
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RT_ASSERT(size > 0);
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/* initialize read and write index */
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rb->read_mirror = rb->read_index = 0;
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rb->write_mirror = rb->write_index = 0;
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/* set buffer pool and size */
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rb->buffer_ptr = pool;
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rb->buffer_size = RT_ALIGN_DOWN(size, RT_ALIGN_SIZE);
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}
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RTM_EXPORT(rt_ringbuffer_init);
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/**
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* put a block of data into ring buffer
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*/
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rt_size_t rt_ringbuffer_put(struct rt_ringbuffer *rb,
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const rt_uint8_t *ptr,
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rt_uint16_t length)
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{
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rt_uint16_t size;
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RT_ASSERT(rb != RT_NULL);
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/* whether has enough space */
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size = rt_ringbuffer_space_len(rb);
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/* no space */
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if (size == 0)
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return 0;
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/* drop some data */
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if (size < length)
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length = size;
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if (rb->buffer_size - rb->write_index > length)
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{
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/* read_index - write_index = empty space */
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memcpy(&rb->buffer_ptr[rb->write_index], ptr, length);
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/* this should not cause overflow because there is enough space for
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* length of data in current mirror */
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rb->write_index += length;
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return length;
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}
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memcpy(&rb->buffer_ptr[rb->write_index],
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&ptr[0],
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rb->buffer_size - rb->write_index);
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memcpy(&rb->buffer_ptr[0],
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&ptr[rb->buffer_size - rb->write_index],
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length - (rb->buffer_size - rb->write_index));
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/* we are going into the other side of the mirror */
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rb->write_mirror = ~rb->write_mirror;
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rb->write_index = length - (rb->buffer_size - rb->write_index);
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return length;
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}
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RTM_EXPORT(rt_ringbuffer_put);
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/**
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* put a block of data into ring buffer
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*
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* When the buffer is full, it will discard the old data.
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*/
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rt_size_t rt_ringbuffer_put_force(struct rt_ringbuffer *rb,
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const rt_uint8_t *ptr,
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rt_uint16_t length)
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{
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rt_uint16_t space_length;
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RT_ASSERT(rb != RT_NULL);
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space_length = rt_ringbuffer_space_len(rb);
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if (length > space_length)
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length = rb->buffer_size;
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if (rb->buffer_size - rb->write_index > length)
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{
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/* read_index - write_index = empty space */
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memcpy(&rb->buffer_ptr[rb->write_index], ptr, length);
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/* this should not cause overflow because there is enough space for
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* length of data in current mirror */
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rb->write_index += length;
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if (length > space_length)
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rb->read_index = rb->write_index;
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return length;
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}
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memcpy(&rb->buffer_ptr[rb->write_index],
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&ptr[0],
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rb->buffer_size - rb->write_index);
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memcpy(&rb->buffer_ptr[0],
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&ptr[rb->buffer_size - rb->write_index],
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length - (rb->buffer_size - rb->write_index));
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/* we are going into the other side of the mirror */
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rb->write_mirror = ~rb->write_mirror;
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rb->write_index = length - (rb->buffer_size - rb->write_index);
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if (length > space_length)
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{
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rb->read_mirror = ~rb->read_mirror;
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rb->read_index = rb->write_index;
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}
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return length;
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}
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RTM_EXPORT(rt_ringbuffer_put_force);
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/**
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* get data from ring buffer
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*/
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rt_size_t rt_ringbuffer_get(struct rt_ringbuffer *rb,
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rt_uint8_t *ptr,
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rt_uint16_t length)
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{
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rt_size_t size;
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RT_ASSERT(rb != RT_NULL);
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/* whether has enough data */
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size = rt_ringbuffer_data_len(rb);
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/* no data */
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if (size == 0)
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return 0;
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/* less data */
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if (size < length)
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length = size;
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if (rb->buffer_size - rb->read_index > length)
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{
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/* copy all of data */
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memcpy(ptr, &rb->buffer_ptr[rb->read_index], length);
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/* this should not cause overflow because there is enough space for
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* length of data in current mirror */
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rb->read_index += length;
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return length;
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}
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memcpy(&ptr[0],
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&rb->buffer_ptr[rb->read_index],
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rb->buffer_size - rb->read_index);
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memcpy(&ptr[rb->buffer_size - rb->read_index],
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&rb->buffer_ptr[0],
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length - (rb->buffer_size - rb->read_index));
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/* we are going into the other side of the mirror */
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rb->read_mirror = ~rb->read_mirror;
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rb->read_index = length - (rb->buffer_size - rb->read_index);
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return length;
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}
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RTM_EXPORT(rt_ringbuffer_get);
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/**
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* put a character into ring buffer
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*/
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rt_size_t rt_ringbuffer_putchar(struct rt_ringbuffer *rb, const rt_uint8_t ch)
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{
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RT_ASSERT(rb != RT_NULL);
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/* whether has enough space */
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if (!rt_ringbuffer_space_len(rb))
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return 0;
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rb->buffer_ptr[rb->write_index] = ch;
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/* flip mirror */
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if (rb->write_index == rb->buffer_size-1)
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{
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rb->write_mirror = ~rb->write_mirror;
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rb->write_index = 0;
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}
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else
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{
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rb->write_index++;
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}
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return 1;
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}
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RTM_EXPORT(rt_ringbuffer_putchar);
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/**
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* put a character into ring buffer
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*
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* When the buffer is full, it will discard one old data.
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*/
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rt_size_t rt_ringbuffer_putchar_force(struct rt_ringbuffer *rb, const rt_uint8_t ch)
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{
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enum rt_ringbuffer_state old_state;
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RT_ASSERT(rb != RT_NULL);
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old_state = rt_ringbuffer_status(rb);
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rb->buffer_ptr[rb->write_index] = ch;
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/* flip mirror */
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if (rb->write_index == rb->buffer_size-1)
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{
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rb->write_mirror = ~rb->write_mirror;
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rb->write_index = 0;
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if (old_state == RT_RINGBUFFER_FULL)
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{
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rb->read_mirror = ~rb->read_mirror;
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rb->read_index = rb->write_index;
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}
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}
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else
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{
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rb->write_index++;
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if (old_state == RT_RINGBUFFER_FULL)
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rb->read_index = rb->write_index;
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}
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return 1;
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}
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RTM_EXPORT(rt_ringbuffer_putchar_force);
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/**
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* get a character from a ringbuffer
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*/
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rt_size_t rt_ringbuffer_getchar(struct rt_ringbuffer *rb, rt_uint8_t *ch)
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{
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RT_ASSERT(rb != RT_NULL);
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/* ringbuffer is empty */
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if (!rt_ringbuffer_data_len(rb))
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return 0;
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/* put character */
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*ch = rb->buffer_ptr[rb->read_index];
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if (rb->read_index == rb->buffer_size-1)
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{
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rb->read_mirror = ~rb->read_mirror;
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rb->read_index = 0;
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}
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else
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{
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rb->read_index++;
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}
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return 1;
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}
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RTM_EXPORT(rt_ringbuffer_getchar);
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/**
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* get the size of data in rb
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*/
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rt_size_t rt_ringbuffer_data_len(struct rt_ringbuffer *rb)
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{
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switch (rt_ringbuffer_status(rb))
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{
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case RT_RINGBUFFER_EMPTY:
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return 0;
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case RT_RINGBUFFER_FULL:
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return rb->buffer_size;
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case RT_RINGBUFFER_HALFFULL:
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default:
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if (rb->write_index > rb->read_index)
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return rb->write_index - rb->read_index;
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else
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return rb->buffer_size - (rb->read_index - rb->write_index);
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};
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}
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RTM_EXPORT(rt_ringbuffer_data_len);
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/**
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* empty the rb
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*/
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void rt_ringbuffer_reset(struct rt_ringbuffer *rb)
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{
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RT_ASSERT(rb != RT_NULL);
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rb->read_mirror = 0;
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rb->read_index = 0;
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rb->write_mirror = 0;
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rb->write_index = 0;
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}
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RTM_EXPORT(rt_ringbuffer_reset);
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#ifdef RT_USING_HEAP
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struct rt_ringbuffer* rt_ringbuffer_create(rt_uint16_t size)
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{
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struct rt_ringbuffer *rb;
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rt_uint8_t *pool;
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RT_ASSERT(size > 0);
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size = RT_ALIGN_DOWN(size, RT_ALIGN_SIZE);
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rb = rt_malloc(sizeof(struct rt_ringbuffer));
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if (rb == RT_NULL)
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goto exit;
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pool = rt_malloc(size);
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if (pool == RT_NULL)
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{
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rt_free(rb);
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goto exit;
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}
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rt_ringbuffer_init(rb, pool, size);
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exit:
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return rb;
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}
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RTM_EXPORT(rt_ringbuffer_create);
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void rt_ringbuffer_destroy(struct rt_ringbuffer *rb)
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{
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RT_ASSERT(rb != RT_NULL);
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rt_free(rb->buffer_ptr);
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rt_free(rb);
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}
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RTM_EXPORT(rt_ringbuffer_destroy);
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#endif
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