3 * BlueZ - Bluetooth protocol stack for Linux
5 * Copyright (C) 2012-2014 Intel Corporation. All rights reserved.
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
31 #include <sys/param.h>
33 #include "src/shared/util.h"
34 #include "src/shared/ringbuf.h"
37 #define MIN(x,y) ((x)<(y)?(x):(y))
45 ringbuf_tracing_func_t in_tracing;
49 #define RINGBUF_RESET 0
51 /* Find last (most siginificant) set bit */
52 static inline unsigned int fls(unsigned int x)
54 return x ? sizeof(x) * 8 - __builtin_clz(x) : 0;
57 /* Round up to nearest power of two */
58 static inline unsigned int align_power2(unsigned int u)
60 return 1 << fls(u - 1);
63 struct ringbuf *ringbuf_new(size_t size)
65 struct ringbuf *ringbuf;
68 if (size < 2 || size > UINT_MAX)
71 /* Find the next power of two for size */
72 real_size = align_power2(size);
74 ringbuf = new0(struct ringbuf, 1);
75 ringbuf->buffer = malloc(real_size);
76 if (!ringbuf->buffer) {
81 ringbuf->size = real_size;
82 ringbuf->in = RINGBUF_RESET;
83 ringbuf->out = RINGBUF_RESET;
88 void ringbuf_free(struct ringbuf *ringbuf)
93 free(ringbuf->buffer);
97 bool ringbuf_set_input_tracing(struct ringbuf *ringbuf,
98 ringbuf_tracing_func_t callback, void *user_data)
103 ringbuf->in_tracing = callback;
104 ringbuf->in_data = user_data;
109 size_t ringbuf_capacity(struct ringbuf *ringbuf)
114 return ringbuf->size;
117 size_t ringbuf_len(struct ringbuf *ringbuf)
122 return ringbuf->in - ringbuf->out;
125 size_t ringbuf_drain(struct ringbuf *ringbuf, size_t count)
132 len = MIN(count, ringbuf->in - ringbuf->out);
138 if (ringbuf->out == ringbuf->in) {
139 ringbuf->in = RINGBUF_RESET;
140 ringbuf->out = RINGBUF_RESET;
146 void *ringbuf_peek(struct ringbuf *ringbuf, size_t offset, size_t *len_nowrap)
151 offset = (ringbuf->out + offset) & (ringbuf->size - 1);
154 size_t len = ringbuf->in - ringbuf->out;
155 *len_nowrap = MIN(len, ringbuf->size - offset);
158 return ringbuf->buffer + offset;
161 ssize_t ringbuf_write(struct ringbuf *ringbuf, int fd)
163 size_t len, offset, end;
167 if (!ringbuf || fd < 0)
170 /* Determine how much data is available */
171 len = ringbuf->in - ringbuf->out;
175 /* Grab data from buffer starting at offset until the end */
176 offset = ringbuf->out & (ringbuf->size - 1);
177 end = MIN(len, ringbuf->size - offset);
179 iov[0].iov_base = ringbuf->buffer + offset;
180 iov[0].iov_len = end;
182 /* Use second vector for remainder from the beginning */
183 iov[1].iov_base = ringbuf->buffer;
184 iov[1].iov_len = len - end;
186 consumed = writev(fd, iov, 2);
190 ringbuf->out += consumed;
192 if (ringbuf->out == ringbuf->in) {
193 ringbuf->in = RINGBUF_RESET;
194 ringbuf->out = RINGBUF_RESET;
200 size_t ringbuf_avail(struct ringbuf *ringbuf)
205 return ringbuf->size - ringbuf->in + ringbuf->out;
208 int ringbuf_printf(struct ringbuf *ringbuf, const char *format, ...)
213 va_start(ap, format);
214 len = ringbuf_vprintf(ringbuf, format, ap);
220 int ringbuf_vprintf(struct ringbuf *ringbuf, const char *format, va_list ap)
222 size_t avail, offset, end;
226 if (!ringbuf || !format)
229 /* Determine maximum length available for string */
230 avail = ringbuf->size - ringbuf->in + ringbuf->out;
234 len = vasprintf(&str, format, ap);
238 if ((size_t) len > avail) {
243 /* Determine possible length of string before wrapping */
244 offset = ringbuf->in & (ringbuf->size - 1);
245 end = MIN((size_t) len, ringbuf->size - offset);
246 memcpy(ringbuf->buffer + offset, str, end);
248 if (ringbuf->in_tracing)
249 ringbuf->in_tracing(ringbuf->buffer + offset, end,
253 /* Put the remainder of string at the beginning */
254 memcpy(ringbuf->buffer, str + end, len - end);
256 if (ringbuf->in_tracing)
257 ringbuf->in_tracing(ringbuf->buffer, len - end,
268 ssize_t ringbuf_read(struct ringbuf *ringbuf, int fd)
270 size_t avail, offset, end;
274 if (!ringbuf || fd < 0)
277 /* Determine how much can actually be consumed */
278 avail = ringbuf->size - ringbuf->in + ringbuf->out;
282 /* Determine how much to consume before wrapping */
283 offset = ringbuf->in & (ringbuf->size - 1);
284 end = MIN(avail, ringbuf->size - offset);
286 iov[0].iov_base = ringbuf->buffer + offset;
287 iov[0].iov_len = end;
289 /* Now put the remainder into the second vector */
290 iov[1].iov_base = ringbuf->buffer;
291 iov[1].iov_len = avail - end;
293 consumed = readv(fd, iov, 2);
297 if (ringbuf->in_tracing) {
298 size_t len = MIN((size_t) consumed, end);
299 ringbuf->in_tracing(ringbuf->buffer + offset, len,
301 if (consumed - len > 0)
302 ringbuf->in_tracing(ringbuf->buffer, consumed - len,
306 ringbuf->in += consumed;