tsrb.h
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1 /*
2  * Copyright (C) 2015 Kaspar Schleiser <kaspar@schleiser.de>
3  *
4  * This file is subject to the terms and conditions of the GNU Lesser
5  * General Public License v2.1. See the file LICENSE in the top level
6  * directory for more details.
7  */
8 
23 #ifndef TSRB_H
24 #define TSRB_H
25 
26 #include <assert.h>
27 #include <stddef.h>
28 #include <stdint.h>
29 
30 #include "irq.h"
31 
32 #ifdef __cplusplus
33 extern "C" {
34 #endif
35 
39 typedef struct tsrb {
40  uint8_t *buf;
41  unsigned int size;
42  unsigned reads;
43  unsigned writes;
45 
49 #define TSRB_INIT(BUF) { (BUF), sizeof (BUF), 0, 0 }
50 
57 static inline void tsrb_init(tsrb_t *rb, uint8_t *buffer, unsigned bufsize)
58 {
59  /* make sure bufsize is a power of two.
60  * http://www.exploringbinary.com/ten-ways-to-check-if-an-integer-is-a-power-of-two-in-c/
61  */
62  assert((bufsize != 0) && ((bufsize & (~bufsize + 1)) == bufsize));
63 
64  rb->buf = buffer;
65  rb->size = bufsize;
66  rb->reads = 0;
67  rb->writes = 0;
68 }
69 
74 static inline void tsrb_clear(tsrb_t *rb)
75 {
76  unsigned irq_state = irq_disable();
77  rb->reads = rb->writes;
78  irq_restore(irq_state);
79 }
80 
87 static inline int tsrb_empty(const tsrb_t *rb)
88 {
89  unsigned irq_state = irq_disable();
90  int retval = (rb->reads == rb->writes);
91  irq_restore(irq_state);
92  return retval;
93 }
94 
100 static inline unsigned int tsrb_avail(const tsrb_t *rb)
101 {
102  unsigned irq_state = irq_disable();
103  int retval = (rb->writes - rb->reads);
104  irq_restore(irq_state);
105  return retval;
106 }
107 
114 static inline int tsrb_full(const tsrb_t *rb)
115 {
116  unsigned irq_state = irq_disable();
117  int retval = (rb->writes - rb->reads) == rb->size;
118  irq_restore(irq_state);
119  return retval;
120 }
121 
127 static inline unsigned int tsrb_free(const tsrb_t *rb)
128 {
129  unsigned irq_state = irq_disable();
130  int retval = (rb->size - rb->writes + rb->reads);
131  irq_restore(irq_state);
132  return retval;
133 }
134 
142 
150 
158 int tsrb_get(tsrb_t *rb, uint8_t *dst, size_t n);
159 
167 int tsrb_peek(tsrb_t *rb, uint8_t *dst, size_t n);
168 
175 int tsrb_drop(tsrb_t *rb, size_t n);
176 
184 int tsrb_add_one(tsrb_t *rb, uint8_t c);
185 
193 int tsrb_add(tsrb_t *rb, const uint8_t *src, size_t n);
194 
195 #ifdef __cplusplus
196 }
197 #endif
198 
199 #endif /* TSRB_H */
POSIX.1-2008 compliant version of the assert macro.
#define assert(cond)
abort the program if assertion is false
Definition: assert.h:113
MAYBE_INLINE void irq_restore(unsigned state)
This function restores the IRQ disable bit in the status register to the value contained within passe...
MAYBE_INLINE unsigned irq_disable(void)
This function sets the IRQ disable bit in the status register.
int tsrb_peek(tsrb_t *rb, uint8_t *dst, size_t n)
Get bytes from ringbuffer, without removing them.
int tsrb_get(tsrb_t *rb, uint8_t *dst, size_t n)
Get bytes from ringbuffer.
int tsrb_add(tsrb_t *rb, const uint8_t *src, size_t n)
Add bytes to ringbuffer.
int tsrb_drop(tsrb_t *rb, size_t n)
Drop bytes from ringbuffer.
static unsigned int tsrb_free(const tsrb_t *rb)
Get free space in ringbuffer.
Definition: tsrb.h:127
static unsigned int tsrb_avail(const tsrb_t *rb)
Get number of bytes available for reading.
Definition: tsrb.h:100
int tsrb_get_one(tsrb_t *rb)
Get a byte from ringbuffer.
struct tsrb tsrb_t
thread-safe ringbuffer struct
static void tsrb_clear(tsrb_t *rb)
Clear a tsrb.
Definition: tsrb.h:74
int tsrb_add_one(tsrb_t *rb, uint8_t c)
Add a byte to ringbuffer.
int tsrb_peek_one(tsrb_t *rb)
Get a byte from ringbuffer, without removing it.
static void tsrb_init(tsrb_t *rb, uint8_t *buffer, unsigned bufsize)
Initialize a tsrb.
Definition: tsrb.h:57
static int tsrb_full(const tsrb_t *rb)
Test if the tsrb is full.
Definition: tsrb.h:114
static int tsrb_empty(const tsrb_t *rb)
Test if the tsrb is empty.
Definition: tsrb.h:87
IRQ driver interface.
thread-safe ringbuffer struct
Definition: tsrb.h:39
unsigned writes
total number of writes
Definition: tsrb.h:43
unsigned reads
total number of reads
Definition: tsrb.h:42
uint8_t * buf
Buffer to operate on.
Definition: tsrb.h:40
unsigned int size
Size of buffer, must be power of 2.
Definition: tsrb.h:41