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Diffstat (limited to 'lf_ring_buffer.h')
-rw-r--r-- | lf_ring_buffer.h | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/lf_ring_buffer.h b/lf_ring_buffer.h new file mode 100644 index 0000000..7c237ab --- /dev/null +++ b/lf_ring_buffer.h @@ -0,0 +1,85 @@ +/* + * File : lf_ring_buffer.h + * Author : Jérémy Zurcher <jeremy@asynk.ch> + * Date : 05/01/010 + * License : + * + * 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 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. + * + */ + +#ifndef _LF_RING_BUFFER_H_ +#define _LF_RING_BUFFER_H_ + +# ifdef __cplusplus +extern "C" { +# endif /* __cplusplus */ + +#define BACKOFF_DELAY_INIT 1000 +#define BACKOFF_DELAY_INC 3000 +#define BACKOFF_DELAY_MAX 90000 + +#define NO_BLOCK 1 /* if buffer is full, leave instead of try again and again */ +#define IS_NOT_BLOCKING( flags ) ( (flags)&NO_BLOCK ) + +#define RB_DATA_SIZE 63 +typedef char rb_data_t; + +typedef struct buffer_el { + char status; + rb_data_t data[RB_DATA_SIZE]; +} lf_buffer_el_t; + +typedef struct ring_buffer { + lf_buffer_el_t *buffer; /* buffer data */ + int n_buf; /* number of buffers */ + int read_from; /* index where to read data from */ + int write_to; /* index where to write data to */ + int write_delay; /* backoff nanosleep to reduce fast looping when writing */ + int read_delay; /* backoff nanosleep to reduce fast looping when reading */ +} lf_ring_buffer_t; + +#define IS_AVAILABLE( idx ) (r->buffer[(idx)].status==0) +#define MARK_AS_FILLED( idx ) { r->buffer[(idx)].status=1; } +#define MARK_AS_READ( idx ) { r->buffer[(idx)].status=0; } + +/* initialize an empty lf_ring_buffer struct */ +lf_ring_buffer_t* lf_ring_buffer_create( int n_buf ); + +/* destroy an lf_ring_buffer strcture */ +void lf_ring_buffer_destroy( lf_ring_buffer_t *r ); + +/* write data into the ring buffer + * return 0 on success + * return -1 if IS_NOT_BLOCKING and buffer is full + */ +int lf_ring_buffer_write( lf_ring_buffer_t *r, rb_data_t *data, int flags ); + +/* read data from the ring buffer + * return 0 on success + * return -1 if IS_NOT_BLOCKING and buffer is empty + */ +int lf_ring_buffer_read( lf_ring_buffer_t *r, rb_data_t *data, int flags ); + +# ifdef __cplusplus +} +# endif /* __cplusplus */ + +# endif /* _LF_RING_BUFFER_H_ */ |