WizziLab / WizziCom

WizziLab's serial protocol library

Dependents:   modem_ref_helper_for_v5_3_217 modem_ref_helper

kal_buf_circ.cpp@9:0140247bab90, 2021-01-25 (annotated)

Committer:
Jeej
Date:
Mon Jan 25 09:45:10 2021 +0000
Revision:
9:0140247bab90
Child:
10:c87566aded6e
Use single byte interrupt to be able to re-sync.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Jeej 9:0140247bab90 1 /// @copyright
Jeej 9:0140247bab90 2 /// ========================================================================={{{
Jeej 9:0140247bab90 3 /// Copyright (c) 2019 WizziLab /
Jeej 9:0140247bab90 4 /// All rights reserved /
Jeej 9:0140247bab90 5 /// /
Jeej 9:0140247bab90 6 /// IMPORTANT: This Software may not be modified, copied or distributed unless /
Jeej 9:0140247bab90 7 /// embedded on a WizziLab product. Other than for the foregoing purpose, this /
Jeej 9:0140247bab90 8 /// Software and/or its documentation may not be used, reproduced, copied, /
Jeej 9:0140247bab90 9 /// prepared derivative works of, modified, performed, distributed, displayed /
Jeej 9:0140247bab90 10 /// or sold for any purpose. For the sole purpose of embedding this Software /
Jeej 9:0140247bab90 11 /// on a WizziLab product, copy, modification and distribution of this /
Jeej 9:0140247bab90 12 /// Software is granted provided that the following conditions are respected: /
Jeej 9:0140247bab90 13 /// /
Jeej 9:0140247bab90 14 /// * Redistributions of source code must retain the above copyright notice, /
Jeej 9:0140247bab90 15 /// this list of conditions and the following disclaimer /
Jeej 9:0140247bab90 16 /// /
Jeej 9:0140247bab90 17 /// * Redistributions in binary form must reproduce the above copyright /
Jeej 9:0140247bab90 18 /// notice, this list of conditions and the following disclaimer in the /
Jeej 9:0140247bab90 19 /// documentation and/or other materials provided with the distribution. /
Jeej 9:0140247bab90 20 /// /
Jeej 9:0140247bab90 21 /// * The name of WizziLab can not be used to endorse or promote products /
Jeej 9:0140247bab90 22 /// derived from this software without specific prior written permission. /
Jeej 9:0140247bab90 23 /// /
Jeej 9:0140247bab90 24 /// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS /
Jeej 9:0140247bab90 25 /// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED /
Jeej 9:0140247bab90 26 /// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR /
Jeej 9:0140247bab90 27 /// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR /
Jeej 9:0140247bab90 28 /// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, /
Jeej 9:0140247bab90 29 /// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, /
Jeej 9:0140247bab90 30 /// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, /
Jeej 9:0140247bab90 31 /// OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY /
Jeej 9:0140247bab90 32 /// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING /
Jeej 9:0140247bab90 33 /// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS /
Jeej 9:0140247bab90 34 /// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. /
Jeej 9:0140247bab90 35 /// WIZZILAB HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, /
Jeej 9:0140247bab90 36 /// ENHANCEMENTS OR MODIFICATIONS. /
Jeej 9:0140247bab90 37 /// /
Jeej 9:0140247bab90 38 /// Should you have any questions regarding your right to use this Software, /
Jeej 9:0140247bab90 39 /// contact WizziLab at www.wizzilab.com. /
Jeej 9:0140247bab90 40 /// /
Jeej 9:0140247bab90 41 /// =========================================================================}}}
Jeej 9:0140247bab90 42 /// @endcopyright
Jeej 9:0140247bab90 43
Jeej 9:0140247bab90 44 /// XXX: New code for reference. Still to be tested.
Jeej 9:0140247bab90 45
Jeej 9:0140247bab90 46 #include "kal_buf_circ.h"
Jeej 9:0140247bab90 47
Jeej 9:0140247bab90 48 #if defined(KAL_MALLOC) && defined(KAL_FREE)
Jeej 9:0140247bab90 49 #ifndef CIRCULAR_BUFFER_MALLOC
Jeej 9:0140247bab90 50 #define CIRCULAR_BUFFER_MALLOC(_s) KAL_MALLOC(_s)
Jeej 9:0140247bab90 51 #endif
Jeej 9:0140247bab90 52 #ifndef CIRCULAR_BUFFER_FREE
Jeej 9:0140247bab90 53 #define CIRCULAR_BUFFER_FREE(_p) KAL_FREE(_p)
Jeej 9:0140247bab90 54 #endif
Jeej 9:0140247bab90 55 #else
Jeej 9:0140247bab90 56 #define CIRCULAR_BUFFER_STATIC_ONLY
Jeej 9:0140247bab90 57 #endif
Jeej 9:0140247bab90 58
Jeej 9:0140247bab90 59 static __inline uint32_t kal_buf_circ_next_head(kal_buf_circ_static_handle_t* h, uint32_t nb_elements)
Jeej 9:0140247bab90 60 {
Jeej 9:0140247bab90 61 uint32_t next = h->head + (nb_elements * h->element_size);
Jeej 9:0140247bab90 62 return (next >= h->max_length)? next - h->max_length : next;
Jeej 9:0140247bab90 63 }
Jeej 9:0140247bab90 64
Jeej 9:0140247bab90 65 static __inline uint32_t kal_buf_circ_next_tail(kal_buf_circ_static_handle_t* h, uint32_t nb_elements)
Jeej 9:0140247bab90 66 {
Jeej 9:0140247bab90 67 uint32_t next = h->tail + (nb_elements * h->element_size);
Jeej 9:0140247bab90 68 return (next >= h->max_length)? next - h->max_length : next;
Jeej 9:0140247bab90 69 }
Jeej 9:0140247bab90 70
Jeej 9:0140247bab90 71 #ifndef CIRCULAR_BUFFER_STATIC_ONLY
Jeej 9:0140247bab90 72 kal_buf_circ_handle_t kal_buf_circ_create(uint32_t nb_elements, uint32_t element_size)
Jeej 9:0140247bab90 73 {
Jeej 9:0140247bab90 74 // Malloc the h and the buffer
Jeej 9:0140247bab90 75 kal_buf_circ_static_handle_t* h = CIRCULAR_BUFFER_MALLOC(sizeof(kal_buf_circ_static_handle_t));
Jeej 9:0140247bab90 76
Jeej 9:0140247bab90 77 h->buffer = (uint8_t*)CIRCULAR_BUFFER_MALLOC((nb_elements + 1) * element_size);
Jeej 9:0140247bab90 78 h->head = 0;
Jeej 9:0140247bab90 79 h->tail = 0;
Jeej 9:0140247bab90 80 h->element_size = element_size;
Jeej 9:0140247bab90 81 h->max_length = (nb_elements + 1) * element_size;
Jeej 9:0140247bab90 82 h->is_static = false;
Jeej 9:0140247bab90 83
Jeej 9:0140247bab90 84 return (kal_buf_circ_handle_t)h;
Jeej 9:0140247bab90 85 }
Jeej 9:0140247bab90 86 #endif
Jeej 9:0140247bab90 87
Jeej 9:0140247bab90 88 int kal_buf_circ_create_static(kal_buf_circ_static_handle_t* static_handle, uint8_t* buffer, uint32_t nb_elements, uint32_t element_size)
Jeej 9:0140247bab90 89 {
Jeej 9:0140247bab90 90 // h and buffer are passed as parameters.
Jeej 9:0140247bab90 91 kal_buf_circ_static_handle_t* h = static_handle;
Jeej 9:0140247bab90 92
Jeej 9:0140247bab90 93 h->buffer = buffer;
Jeej 9:0140247bab90 94 h->head = 0;
Jeej 9:0140247bab90 95 h->tail = 0;
Jeej 9:0140247bab90 96 h->element_size = element_size;
Jeej 9:0140247bab90 97 h->max_length = (nb_elements + 1) * element_size;
Jeej 9:0140247bab90 98 h->is_static = true;
Jeej 9:0140247bab90 99
Jeej 9:0140247bab90 100 return 0;
Jeej 9:0140247bab90 101 }
Jeej 9:0140247bab90 102
Jeej 9:0140247bab90 103 int kal_buf_circ_delete(kal_buf_circ_handle_t handle)
Jeej 9:0140247bab90 104 {
Jeej 9:0140247bab90 105 kal_buf_circ_static_handle_t* h = (kal_buf_circ_static_handle_t*)handle;
Jeej 9:0140247bab90 106
Jeej 9:0140247bab90 107 if (h->is_static)
Jeej 9:0140247bab90 108 {
Jeej 9:0140247bab90 109 // Set h to 0
Jeej 9:0140247bab90 110 memset(h->buffer, 0, h->max_length);
Jeej 9:0140247bab90 111 memset(h, 0, sizeof(kal_buf_circ_static_handle_t));
Jeej 9:0140247bab90 112 }
Jeej 9:0140247bab90 113 #ifndef CIRCULAR_BUFFER_STATIC_ONLY
Jeej 9:0140247bab90 114 else
Jeej 9:0140247bab90 115 {
Jeej 9:0140247bab90 116 CIRCULAR_BUFFER_FREE(h->buffer);
Jeej 9:0140247bab90 117 CIRCULAR_BUFFER_FREE(h);
Jeej 9:0140247bab90 118 }
Jeej 9:0140247bab90 119 #endif
Jeej 9:0140247bab90 120
Jeej 9:0140247bab90 121 return 0;
Jeej 9:0140247bab90 122 }
Jeej 9:0140247bab90 123
Jeej 9:0140247bab90 124 int kal_buf_circ_reset(kal_buf_circ_handle_t handle)
Jeej 9:0140247bab90 125 {
Jeej 9:0140247bab90 126 kal_buf_circ_static_handle_t* h = (kal_buf_circ_static_handle_t*)handle;
Jeej 9:0140247bab90 127
Jeej 9:0140247bab90 128 h->head = 0;
Jeej 9:0140247bab90 129 h->tail = 0;
Jeej 9:0140247bab90 130 memset(h->buffer, 0, h->max_length);
Jeej 9:0140247bab90 131
Jeej 9:0140247bab90 132 return 0;
Jeej 9:0140247bab90 133 }
Jeej 9:0140247bab90 134
Jeej 9:0140247bab90 135 __inline int kal_buf_circ_full(kal_buf_circ_handle_t handle)
Jeej 9:0140247bab90 136 {
Jeej 9:0140247bab90 137 kal_buf_circ_static_handle_t* h = (kal_buf_circ_static_handle_t*)handle;
Jeej 9:0140247bab90 138
Jeej 9:0140247bab90 139 // if the next head is the tail, circular buffer is full
Jeej 9:0140247bab90 140 return (kal_buf_circ_next_head(h, 1) == h->tail)? true : false;
Jeej 9:0140247bab90 141 }
Jeej 9:0140247bab90 142
Jeej 9:0140247bab90 143 __inline int kal_buf_circ_empty(kal_buf_circ_handle_t handle)
Jeej 9:0140247bab90 144 {
Jeej 9:0140247bab90 145 kal_buf_circ_static_handle_t* h = (kal_buf_circ_static_handle_t*)handle;
Jeej 9:0140247bab90 146
Jeej 9:0140247bab90 147 // if the head isn't ahead of the tail, we don't have any elements
Jeej 9:0140247bab90 148 return (h->head == h->tail)? true : false;
Jeej 9:0140247bab90 149 }
Jeej 9:0140247bab90 150
Jeej 9:0140247bab90 151 uint32_t kal_buf_circ_size(kal_buf_circ_handle_t handle)
Jeej 9:0140247bab90 152 {
Jeej 9:0140247bab90 153 kal_buf_circ_static_handle_t* h = (kal_buf_circ_static_handle_t*)handle;
Jeej 9:0140247bab90 154
Jeej 9:0140247bab90 155 // head is ahead of tail
Jeej 9:0140247bab90 156 if (h->head >= h->tail)
Jeej 9:0140247bab90 157 {
Jeej 9:0140247bab90 158 // return the difference
Jeej 9:0140247bab90 159 return (h->head - h->tail) / h->element_size;
Jeej 9:0140247bab90 160 }
Jeej 9:0140247bab90 161 else
Jeej 9:0140247bab90 162 {
Jeej 9:0140247bab90 163 // else add max_length
Jeej 9:0140247bab90 164 return (h->max_length + h->head - h->tail) / h->element_size;
Jeej 9:0140247bab90 165 }
Jeej 9:0140247bab90 166 }
Jeej 9:0140247bab90 167
Jeej 9:0140247bab90 168 int kal_buf_circ_push(kal_buf_circ_handle_t handle, uint8_t* p)
Jeej 9:0140247bab90 169 {
Jeej 9:0140247bab90 170 kal_buf_circ_static_handle_t* h = (kal_buf_circ_static_handle_t*)handle;
Jeej 9:0140247bab90 171
Jeej 9:0140247bab90 172 // check if circular buffer is full
Jeej 9:0140247bab90 173 if (kal_buf_circ_full(handle))
Jeej 9:0140247bab90 174 {
Jeej 9:0140247bab90 175 return -1; // and return with an error.
Jeej 9:0140247bab90 176 }
Jeej 9:0140247bab90 177
Jeej 9:0140247bab90 178 // next is where head will point to after this write.
Jeej 9:0140247bab90 179 uint32_t next = kal_buf_circ_next_head(h, 1);
Jeej 9:0140247bab90 180
Jeej 9:0140247bab90 181 // Load data and then move
Jeej 9:0140247bab90 182 memcpy(&(h->buffer[h->head]), p, h->element_size);
Jeej 9:0140247bab90 183
Jeej 9:0140247bab90 184 // head to next data offset.
Jeej 9:0140247bab90 185 h->head = next;
Jeej 9:0140247bab90 186
Jeej 9:0140247bab90 187 // return success to indicate successful push.
Jeej 9:0140247bab90 188 return 0;
Jeej 9:0140247bab90 189 }
Jeej 9:0140247bab90 190
Jeej 9:0140247bab90 191 int kal_buf_circ_pop(kal_buf_circ_handle_t handle, uint8_t* p)
Jeej 9:0140247bab90 192 {
Jeej 9:0140247bab90 193 kal_buf_circ_static_handle_t* h = (kal_buf_circ_static_handle_t*)handle;
Jeej 9:0140247bab90 194
Jeej 9:0140247bab90 195 // check if circular buffer is empty
Jeej 9:0140247bab90 196 if (kal_buf_circ_empty(handle))
Jeej 9:0140247bab90 197 {
Jeej 9:0140247bab90 198 return -1; // and return with an error
Jeej 9:0140247bab90 199 }
Jeej 9:0140247bab90 200
Jeej 9:0140247bab90 201 // next is where tail will point to after this read.
Jeej 9:0140247bab90 202 uint32_t next = kal_buf_circ_next_tail(h, 1);
Jeej 9:0140247bab90 203
Jeej 9:0140247bab90 204 if (p)
Jeej 9:0140247bab90 205 {
Jeej 9:0140247bab90 206 // Read data and then move
Jeej 9:0140247bab90 207 memcpy(p, &(h->buffer[h->tail]), h->element_size);
Jeej 9:0140247bab90 208 }
Jeej 9:0140247bab90 209
Jeej 9:0140247bab90 210 // tail to next data offset.
Jeej 9:0140247bab90 211 h->tail = next;
Jeej 9:0140247bab90 212
Jeej 9:0140247bab90 213 // return success to indicate successful pop.
Jeej 9:0140247bab90 214 return 0;
Jeej 9:0140247bab90 215 }
Jeej 9:0140247bab90 216
Jeej 9:0140247bab90 217 int kal_buf_circ_peek(kal_buf_circ_handle_t handle, uint8_t* p)
Jeej 9:0140247bab90 218 {
Jeej 9:0140247bab90 219 kal_buf_circ_static_handle_t* h = (kal_buf_circ_static_handle_t*)handle;
Jeej 9:0140247bab90 220
Jeej 9:0140247bab90 221 // check if circular buffer is empty
Jeej 9:0140247bab90 222 if (kal_buf_circ_empty(handle))
Jeej 9:0140247bab90 223 {
Jeej 9:0140247bab90 224 return -1; // and return with an error
Jeej 9:0140247bab90 225 }
Jeej 9:0140247bab90 226
Jeej 9:0140247bab90 227 // Read data
Jeej 9:0140247bab90 228 memcpy(p, &(h->buffer[h->tail]), h->element_size);
Jeej 9:0140247bab90 229
Jeej 9:0140247bab90 230 // return success to indicate successful peek.
Jeej 9:0140247bab90 231 return 0;
Jeej 9:0140247bab90 232 }
Jeej 9:0140247bab90 233
Jeej 9:0140247bab90 234 int kal_buf_circ_put(kal_buf_circ_handle_t handle, uint8_t* p, uint32_t nb_elements)
Jeej 9:0140247bab90 235 {
Jeej 9:0140247bab90 236 kal_buf_circ_static_handle_t* h = (kal_buf_circ_static_handle_t*)handle;
Jeej 9:0140247bab90 237
Jeej 9:0140247bab90 238 // Check if there is enough available spots in the buffer
Jeej 9:0140247bab90 239 if (nb_elements + kal_buf_circ_size(handle) >= h->max_length / h->element_size)
Jeej 9:0140247bab90 240 {
Jeej 9:0140247bab90 241 return -1; // and return with an error
Jeej 9:0140247bab90 242 }
Jeej 9:0140247bab90 243
Jeej 9:0140247bab90 244 // check if write should be done in two parts
Jeej 9:0140247bab90 245 uint32_t available_now = (h->max_length - h->head) / h->element_size;
Jeej 9:0140247bab90 246 if (nb_elements > available_now)
Jeej 9:0140247bab90 247 {
Jeej 9:0140247bab90 248 // write first part up to max_length
Jeej 9:0140247bab90 249 if (kal_buf_circ_put(handle, p, available_now))
Jeej 9:0140247bab90 250 {
Jeej 9:0140247bab90 251 return -1;
Jeej 9:0140247bab90 252 }
Jeej 9:0140247bab90 253
Jeej 9:0140247bab90 254 // increment write pointer
Jeej 9:0140247bab90 255 p += available_now * h->element_size;
Jeej 9:0140247bab90 256 // subtract what we just wrote
Jeej 9:0140247bab90 257 nb_elements -= available_now;
Jeej 9:0140247bab90 258 }
Jeej 9:0140247bab90 259
Jeej 9:0140247bab90 260 // next is where head will point to after this write.
Jeej 9:0140247bab90 261 uint32_t next = kal_buf_circ_next_head(h, nb_elements);
Jeej 9:0140247bab90 262
Jeej 9:0140247bab90 263 // write data
Jeej 9:0140247bab90 264 memcpy(&(h->buffer[h->head]), p, nb_elements * h->element_size);
Jeej 9:0140247bab90 265
Jeej 9:0140247bab90 266 // head to next data offset.
Jeej 9:0140247bab90 267 h->head = next;
Jeej 9:0140247bab90 268
Jeej 9:0140247bab90 269 // return success to indicate successful get.
Jeej 9:0140247bab90 270 return 0;
Jeej 9:0140247bab90 271 }
Jeej 9:0140247bab90 272
Jeej 9:0140247bab90 273 int kal_buf_circ_get(kal_buf_circ_handle_t handle, uint8_t* p, uint32_t nb_elements)
Jeej 9:0140247bab90 274 {
Jeej 9:0140247bab90 275 kal_buf_circ_static_handle_t* h = (kal_buf_circ_static_handle_t*)handle;
Jeej 9:0140247bab90 276
Jeej 9:0140247bab90 277 // Check if there is enough elements in the buffer
Jeej 9:0140247bab90 278 if (nb_elements > kal_buf_circ_size(handle))
Jeej 9:0140247bab90 279 {
Jeej 9:0140247bab90 280 return -1; // and return with an error
Jeej 9:0140247bab90 281 }
Jeej 9:0140247bab90 282
Jeej 9:0140247bab90 283 // check if read should be done in two parts
Jeej 9:0140247bab90 284 uint32_t available_now = (h->max_length - h->tail) / h->element_size;
Jeej 9:0140247bab90 285 if (nb_elements > available_now)
Jeej 9:0140247bab90 286 {
Jeej 9:0140247bab90 287 // get first part up to max_length
Jeej 9:0140247bab90 288 if (kal_buf_circ_get(handle, p, available_now))
Jeej 9:0140247bab90 289 {
Jeej 9:0140247bab90 290 return -1;
Jeej 9:0140247bab90 291 }
Jeej 9:0140247bab90 292
Jeej 9:0140247bab90 293 if (p)
Jeej 9:0140247bab90 294 {
Jeej 9:0140247bab90 295 // increment read pointer
Jeej 9:0140247bab90 296 p += available_now * h->element_size;
Jeej 9:0140247bab90 297 }
Jeej 9:0140247bab90 298 // subtract what we just read
Jeej 9:0140247bab90 299 nb_elements -= available_now;
Jeej 9:0140247bab90 300 }
Jeej 9:0140247bab90 301
Jeej 9:0140247bab90 302 // next is where tail will point to after this read.
Jeej 9:0140247bab90 303 uint32_t next = kal_buf_circ_next_tail(h, nb_elements);
Jeej 9:0140247bab90 304
Jeej 9:0140247bab90 305 if (p)
Jeej 9:0140247bab90 306 {
Jeej 9:0140247bab90 307 // read data
Jeej 9:0140247bab90 308 memcpy(p, &(h->buffer[h->tail]), nb_elements * h->element_size);
Jeej 9:0140247bab90 309 }
Jeej 9:0140247bab90 310
Jeej 9:0140247bab90 311 // tail to next data offset.
Jeej 9:0140247bab90 312 h->tail = next;
Jeej 9:0140247bab90 313
Jeej 9:0140247bab90 314 // return success to indicate successful get.
Jeej 9:0140247bab90 315 return 0;
Jeej 9:0140247bab90 316 }
Jeej 9:0140247bab90 317
Jeej 9:0140247bab90 318 int kal_buf_circ_fetch(kal_buf_circ_handle_t handle, uint8_t* p, uint32_t nb_elements)
Jeej 9:0140247bab90 319 {
Jeej 9:0140247bab90 320 kal_buf_circ_static_handle_t* h = (kal_buf_circ_static_handle_t*)handle;
Jeej 9:0140247bab90 321
Jeej 9:0140247bab90 322 // Check if there is enough elements in the buffer
Jeej 9:0140247bab90 323 if (nb_elements > kal_buf_circ_size(handle))
Jeej 9:0140247bab90 324 {
Jeej 9:0140247bab90 325 return -1; // and return with an error
Jeej 9:0140247bab90 326 }
Jeej 9:0140247bab90 327
Jeej 9:0140247bab90 328 // check if read should be done in two parts
Jeej 9:0140247bab90 329 uint32_t available_now = (h->max_length - h->tail) / h->element_size;
Jeej 9:0140247bab90 330 if (nb_elements > available_now)
Jeej 9:0140247bab90 331 {
Jeej 9:0140247bab90 332 // get first part from tail up to max_length
Jeej 9:0140247bab90 333 memcpy(p, &(h->buffer[h->tail]), available_now * h->element_size);
Jeej 9:0140247bab90 334
Jeej 9:0140247bab90 335 // increment read pointer
Jeej 9:0140247bab90 336 p += available_now * h->element_size;
Jeej 9:0140247bab90 337
Jeej 9:0140247bab90 338 // subtract what we just read
Jeej 9:0140247bab90 339 nb_elements -= available_now;
Jeej 9:0140247bab90 340
Jeej 9:0140247bab90 341 // get second part from 0 up to remaining length
Jeej 9:0140247bab90 342 memcpy(p, &(h->buffer[0]), nb_elements * h->element_size);
Jeej 9:0140247bab90 343 }
Jeej 9:0140247bab90 344 else
Jeej 9:0140247bab90 345 {
Jeej 9:0140247bab90 346 // get data from tail
Jeej 9:0140247bab90 347 memcpy(p, &(h->buffer[h->tail]), nb_elements * h->element_size);
Jeej 9:0140247bab90 348 }
Jeej 9:0140247bab90 349
Jeej 9:0140247bab90 350 // return success to indicate successful fetch.
Jeej 9:0140247bab90 351 return 0;
Jeej 9:0140247bab90 352 }
Jeej 9:0140247bab90 353
Jeej 9:0140247bab90 354 int kal_buf_circ_erase(kal_buf_circ_handle_t handle)
Jeej 9:0140247bab90 355 {
Jeej 9:0140247bab90 356 kal_buf_circ_static_handle_t* h = (kal_buf_circ_static_handle_t*)handle;
Jeej 9:0140247bab90 357
Jeej 9:0140247bab90 358 // check if circular buffer is empty
Jeej 9:0140247bab90 359 if (kal_buf_circ_empty(handle))
Jeej 9:0140247bab90 360 {
Jeej 9:0140247bab90 361 return -1; // and return with an error
Jeej 9:0140247bab90 362 }
Jeej 9:0140247bab90 363
Jeej 9:0140247bab90 364 // head is at 0, we wrap back
Jeej 9:0140247bab90 365 if (h->head == 0)
Jeej 9:0140247bab90 366 {
Jeej 9:0140247bab90 367 h->head = h->max_length - h->element_size;
Jeej 9:0140247bab90 368 }
Jeej 9:0140247bab90 369 // else go back one element
Jeej 9:0140247bab90 370 else
Jeej 9:0140247bab90 371 {
Jeej 9:0140247bab90 372 h->head = h->head - h->element_size;
Jeej 9:0140247bab90 373 }
Jeej 9:0140247bab90 374
Jeej 9:0140247bab90 375 // return success to indicate successful erase.
Jeej 9:0140247bab90 376 return 0;
Jeej 9:0140247bab90 377 }
Jeej 9:0140247bab90 378