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39 * modification, are permitted provided that the following conditions are met:
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70 * This structure is the header of a cirbuf type.
73 unsigned int maxlen; /**< total len of the fifo (number of elements) */
74 unsigned int start; /**< indice of the first elt */
75 unsigned int end; /**< indice of the last elt */
76 unsigned int len; /**< current len of fifo */
80 /* #define CIRBUF_DEBUG */
83 #define dprintf(fmt, ...) printf("line %3.3d - " fmt, __LINE__, ##__VA_ARGS__)
85 #define dprintf(args...) do {} while(0)
90 * Init the circular buffer
92 void cirbuf_init(struct cirbuf *cbuf, char *buf, unsigned int start, unsigned int maxlen);
96 * Return 1 if the circular buffer is full
98 #define CIRBUF_IS_FULL(cirbuf) ((cirbuf)->maxlen == (cirbuf)->len)
101 * Return 1 if the circular buffer is empty
103 #define CIRBUF_IS_EMPTY(cirbuf) ((cirbuf)->len == 0)
106 * return current size of the circular buffer (number of used elements)
108 #define CIRBUF_GET_LEN(cirbuf) ((cirbuf)->len)
111 * return size of the circular buffer (used + free elements)
113 #define CIRBUF_GET_MAXLEN(cirbuf) ((cirbuf)->maxlen)
116 * return the number of free elts
118 #define CIRBUF_GET_FREELEN(cirbuf) ((cirbuf)->maxlen - (cirbuf)->len)
121 * Iterator for a circular buffer
122 * c: struct cirbuf pointer
123 * i: an integer type internally used in the macro
124 * e: char that takes the value for each iteration
126 #define CIRBUF_FOREACH(c, i, e) \
127 for ( i=0, e=(c)->buf[(c)->start] ; \
129 i ++, e=(c)->buf[((c)->start+i)%((c)->maxlen)])
133 * Add a character at head of the circular buffer. Return 0 on success, or
134 * a negative value on error.
136 int cirbuf_add_head_safe(struct cirbuf *cbuf, char c);
139 * Add a character at head of the circular buffer. You _must_ check that you
140 * have enough free space in the buffer before calling this func.
142 void cirbuf_add_head(struct cirbuf *cbuf, char c);
145 * Add a character at tail of the circular buffer. Return 0 on success, or
146 * a negative value on error.
148 int cirbuf_add_tail_safe(struct cirbuf *cbuf, char c);
151 * Add a character at tail of the circular buffer. You _must_ check that you
152 * have enough free space in the buffer before calling this func.
154 void cirbuf_add_tail(struct cirbuf *cbuf, char c);
157 * Remove a char at the head of the circular buffer. Return 0 on
158 * success, or a negative value on error.
160 int cirbuf_del_head_safe(struct cirbuf *cbuf);
163 * Remove a char at the head of the circular buffer. You _must_ check
164 * that buffer is not empty before calling the function.
166 void cirbuf_del_head(struct cirbuf *cbuf);
169 * Remove a char at the tail of the circular buffer. Return 0 on
170 * success, or a negative value on error.
172 int cirbuf_del_tail_safe(struct cirbuf *cbuf);
175 * Remove a char at the tail of the circular buffer. You _must_ check
176 * that buffer is not empty before calling the function.
178 void cirbuf_del_tail(struct cirbuf *cbuf);
181 * Return the head of the circular buffer. You _must_ check that
182 * buffer is not empty before calling the function.
184 char cirbuf_get_head(struct cirbuf *cbuf);
187 * Return the tail of the circular buffer. You _must_ check that
188 * buffer is not empty before calling the function.
190 char cirbuf_get_tail(struct cirbuf *cbuf);
193 * Add a buffer at head of the circular buffer. 'c' is a pointer to a
194 * buffer, and n is the number of char to add. Return the number of
195 * copied bytes on success, or a negative value on error.
197 int cirbuf_add_buf_head(struct cirbuf *cbuf, const char *c, unsigned int n);
200 * Add a buffer at tail of the circular buffer. 'c' is a pointer to a
201 * buffer, and n is the number of char to add. Return the number of
202 * copied bytes on success, or a negative value on error.
204 int cirbuf_add_buf_tail(struct cirbuf *cbuf, const char *c, unsigned int n);
207 * Remove chars at the head of the circular buffer. Return 0 on
208 * success, or a negative value on error.
210 int cirbuf_del_buf_head(struct cirbuf *cbuf, unsigned int size);
213 * Remove chars at the tail of the circular buffer. Return 0 on
214 * success, or a negative value on error.
216 int cirbuf_del_buf_tail(struct cirbuf *cbuf, unsigned int size);
219 * Copy a maximum of 'size' characters from the head of the circular
220 * buffer to a flat one pointed by 'c'. Return the number of copied
223 int cirbuf_get_buf_head(struct cirbuf *cbuf, char *c, unsigned int size);
226 * Copy a maximum of 'size' characters from the tail of the circular
227 * buffer to a flat one pointed by 'c'. Return the number of copied
230 int cirbuf_get_buf_tail(struct cirbuf *cbuf, char *c, unsigned int size);
234 * Set the start of the data to the index 0 of the internal buffer.
236 void cirbuf_align_left(struct cirbuf *cbuf);
239 * Set the end of the data to the last index of the internal buffer.
241 void cirbuf_align_right(struct cirbuf *cbuf);
247 #endif /* _CIRBUF_H_ */