Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 1 | /* bit vector utility routines */ |
| 2 | |
| 3 | /* (C) 2009 by Harald Welte <laforge@gnumonks.org> |
Max | a15f05f | 2016-01-26 10:43:15 +0100 | [diff] [blame] | 4 | * (C) 2012 Ivan Klyuchnikov |
Jacob Erlbeck | 5f349be | 2015-12-21 16:04:03 +0100 | [diff] [blame] | 5 | * (C) 2015 by Sysmocom s.f.m.c. GmbH |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 6 | * |
| 7 | * All Rights Reserved |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation; either version 2 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License along |
| 20 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 21 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 22 | * |
| 23 | */ |
| 24 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 25 | /*! \addtogroup bitvec |
| 26 | * @{ |
| 27 | */ |
| 28 | |
| 29 | /*! \file bitvec.c |
| 30 | * \brief Osmocom bit vector abstraction |
| 31 | */ |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 32 | |
| 33 | #include <errno.h> |
| 34 | #include <stdint.h> |
Jacob Erlbeck | 5f349be | 2015-12-21 16:04:03 +0100 | [diff] [blame] | 35 | #include <string.h> |
Max | a15f05f | 2016-01-26 10:43:15 +0100 | [diff] [blame] | 36 | #include <stdio.h> |
Max | 0a59e98 | 2016-02-05 13:55:37 +0100 | [diff] [blame] | 37 | #include <stdbool.h> |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 38 | |
Max | 0a59e98 | 2016-02-05 13:55:37 +0100 | [diff] [blame] | 39 | #include <osmocom/core/bits.h> |
Pablo Neira Ayuso | 8341934 | 2011-03-22 16:36:13 +0100 | [diff] [blame] | 40 | #include <osmocom/core/bitvec.h> |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 41 | |
| 42 | #define BITNUM_FROM_COMP(byte, bit) ((byte*8)+bit) |
| 43 | |
| 44 | static inline unsigned int bytenum_from_bitnum(unsigned int bitnum) |
| 45 | { |
| 46 | unsigned int bytenum = bitnum / 8; |
| 47 | |
| 48 | return bytenum; |
| 49 | } |
| 50 | |
| 51 | /* convert ZERO/ONE/L/H to a bitmask at given pos in a byte */ |
| 52 | static uint8_t bitval2mask(enum bit_value bit, uint8_t bitnum) |
| 53 | { |
| 54 | int bitval; |
| 55 | |
| 56 | switch (bit) { |
| 57 | case ZERO: |
| 58 | bitval = (0 << bitnum); |
| 59 | break; |
| 60 | case ONE: |
| 61 | bitval = (1 << bitnum); |
| 62 | break; |
| 63 | case L: |
| 64 | bitval = ((0x2b ^ (0 << bitnum)) & (1 << bitnum)); |
| 65 | break; |
| 66 | case H: |
| 67 | bitval = ((0x2b ^ (1 << bitnum)) & (1 << bitnum)); |
| 68 | break; |
| 69 | default: |
| 70 | return 0; |
| 71 | } |
| 72 | return bitval; |
| 73 | } |
| 74 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 75 | /*! \brief check if the bit is 0 or 1 for a given position inside a bitvec |
| 76 | * \param[in] bv the bit vector on which to check |
| 77 | * \param[in] bitnr the bit number inside the bit vector to check |
| 78 | * \returns |
| 79 | */ |
Harald Welte | d9abf01 | 2010-03-06 11:28:49 +0100 | [diff] [blame] | 80 | enum bit_value bitvec_get_bit_pos(const struct bitvec *bv, unsigned int bitnr) |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 81 | { |
| 82 | unsigned int bytenum = bytenum_from_bitnum(bitnr); |
| 83 | unsigned int bitnum = 7 - (bitnr % 8); |
| 84 | uint8_t bitval; |
| 85 | |
| 86 | if (bytenum >= bv->data_len) |
| 87 | return -EINVAL; |
| 88 | |
| 89 | bitval = bitval2mask(ONE, bitnum); |
| 90 | |
| 91 | if (bv->data[bytenum] & bitval) |
| 92 | return ONE; |
| 93 | |
| 94 | return ZERO; |
| 95 | } |
| 96 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 97 | /*! \brief check if the bit is L or H for a given position inside a bitvec |
| 98 | * \param[in] bv the bit vector on which to check |
| 99 | * \param[in] bitnr the bit number inside the bit vector to check |
| 100 | */ |
Andreas.Eversberg | 0ebd688 | 2010-05-09 09:36:54 +0000 | [diff] [blame] | 101 | enum bit_value bitvec_get_bit_pos_high(const struct bitvec *bv, |
| 102 | unsigned int bitnr) |
| 103 | { |
| 104 | unsigned int bytenum = bytenum_from_bitnum(bitnr); |
| 105 | unsigned int bitnum = 7 - (bitnr % 8); |
| 106 | uint8_t bitval; |
| 107 | |
| 108 | if (bytenum >= bv->data_len) |
| 109 | return -EINVAL; |
| 110 | |
| 111 | bitval = bitval2mask(H, bitnum); |
| 112 | |
Andreas.Eversberg | dc0ebdf | 2010-10-24 11:59:33 +0200 | [diff] [blame] | 113 | if ((bv->data[bytenum] & (1 << bitnum)) == bitval) |
Andreas.Eversberg | 0ebd688 | 2010-05-09 09:36:54 +0000 | [diff] [blame] | 114 | return H; |
| 115 | |
| 116 | return L; |
| 117 | } |
| 118 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 119 | /*! \brief get the Nth set bit inside the bit vector |
| 120 | * \param[in] bv the bit vector to use |
| 121 | * \param[in] n the bit number to get |
| 122 | * \returns the bit number (offset) of the Nth set bit in \a bv |
| 123 | */ |
Harald Welte | d9abf01 | 2010-03-06 11:28:49 +0100 | [diff] [blame] | 124 | unsigned int bitvec_get_nth_set_bit(const struct bitvec *bv, unsigned int n) |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 125 | { |
| 126 | unsigned int i, k = 0; |
| 127 | |
| 128 | for (i = 0; i < bv->data_len*8; i++) { |
| 129 | if (bitvec_get_bit_pos(bv, i) == ONE) { |
| 130 | k++; |
| 131 | if (k == n) |
| 132 | return i; |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | return 0; |
| 137 | } |
| 138 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 139 | /*! \brief set a bit at given position in a bit vector |
| 140 | * \param[in] bv bit vector on which to operate |
Katerina Barone-Adesi | c28c6a0 | 2013-02-15 13:27:59 +0100 | [diff] [blame] | 141 | * \param[in] bitnr number of bit to be set |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 142 | * \param[in] bit value to which the bit is to be set |
Max | 912bc6f | 2016-01-28 12:07:12 +0100 | [diff] [blame] | 143 | * \returns 0 on success, negative value on error |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 144 | */ |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 145 | int bitvec_set_bit_pos(struct bitvec *bv, unsigned int bitnr, |
| 146 | enum bit_value bit) |
| 147 | { |
| 148 | unsigned int bytenum = bytenum_from_bitnum(bitnr); |
| 149 | unsigned int bitnum = 7 - (bitnr % 8); |
| 150 | uint8_t bitval; |
| 151 | |
| 152 | if (bytenum >= bv->data_len) |
| 153 | return -EINVAL; |
| 154 | |
| 155 | /* first clear the bit */ |
| 156 | bitval = bitval2mask(ONE, bitnum); |
| 157 | bv->data[bytenum] &= ~bitval; |
| 158 | |
| 159 | /* then set it to desired value */ |
| 160 | bitval = bitval2mask(bit, bitnum); |
| 161 | bv->data[bytenum] |= bitval; |
| 162 | |
| 163 | return 0; |
| 164 | } |
| 165 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 166 | /*! \brief set the next bit inside a bitvec |
| 167 | * \param[in] bv bit vector to be used |
| 168 | * \param[in] bit value of the bit to be set |
Max | 912bc6f | 2016-01-28 12:07:12 +0100 | [diff] [blame] | 169 | * \returns 0 on success, negative value on error |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 170 | */ |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 171 | int bitvec_set_bit(struct bitvec *bv, enum bit_value bit) |
| 172 | { |
| 173 | int rc; |
| 174 | |
| 175 | rc = bitvec_set_bit_pos(bv, bv->cur_bit, bit); |
| 176 | if (!rc) |
| 177 | bv->cur_bit++; |
| 178 | |
| 179 | return rc; |
| 180 | } |
| 181 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 182 | /*! \brief get the next bit (low/high) inside a bitvec */ |
Andreas.Eversberg | 0ebd688 | 2010-05-09 09:36:54 +0000 | [diff] [blame] | 183 | int bitvec_get_bit_high(struct bitvec *bv) |
| 184 | { |
| 185 | int rc; |
| 186 | |
| 187 | rc = bitvec_get_bit_pos_high(bv, bv->cur_bit); |
| 188 | if (rc >= 0) |
| 189 | bv->cur_bit++; |
| 190 | |
| 191 | return rc; |
| 192 | } |
| 193 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 194 | /*! \brief set multiple bits (based on array of bitvals) at current pos |
| 195 | * \param[in] bv bit vector |
| 196 | * \param[in] bits array of \ref bit_value |
| 197 | * \param[in] count number of bits to set |
| 198 | */ |
Max | e49af08 | 2016-01-22 16:46:56 +0100 | [diff] [blame] | 199 | int bitvec_set_bits(struct bitvec *bv, enum bit_value *bits, unsigned int count) |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 200 | { |
| 201 | int i, rc; |
| 202 | |
| 203 | for (i = 0; i < count; i++) { |
| 204 | rc = bitvec_set_bit(bv, bits[i]); |
| 205 | if (rc) |
| 206 | return rc; |
| 207 | } |
| 208 | |
| 209 | return 0; |
| 210 | } |
| 211 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 212 | /*! \brief set multiple bits (based on numeric value) at current pos */ |
Max | e49af08 | 2016-01-22 16:46:56 +0100 | [diff] [blame] | 213 | int bitvec_set_uint(struct bitvec *bv, unsigned int ui, unsigned int num_bits) |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 214 | { |
Max | e49af08 | 2016-01-22 16:46:56 +0100 | [diff] [blame] | 215 | int rc; |
| 216 | unsigned i; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 217 | for (i = 0; i < num_bits; i++) { |
| 218 | int bit = 0; |
Holger Hans Peter Freyther | ab0eb96 | 2016-02-18 20:28:25 +0100 | [diff] [blame] | 219 | if (ui & (1u << (num_bits - i - 1))) |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 220 | bit = 1; |
| 221 | rc = bitvec_set_bit(bv, bit); |
| 222 | if (rc) |
| 223 | return rc; |
| 224 | } |
| 225 | |
| 226 | return 0; |
| 227 | } |
| 228 | |
Max | 0a59e98 | 2016-02-05 13:55:37 +0100 | [diff] [blame] | 229 | /*! \brief get multiple bits (num_bits) from beginning of vector (MSB side) */ |
| 230 | int16_t bitvec_get_int16_msb(const struct bitvec *bv, unsigned int num_bits) |
| 231 | { |
| 232 | if (num_bits > 15 || bv->cur_bit < num_bits) |
| 233 | return -EINVAL; |
| 234 | |
| 235 | if (num_bits < 9) |
| 236 | return bv->data[0] >> (8 - num_bits); |
| 237 | |
| 238 | return osmo_load16be(bv->data) >> (16 - num_bits); |
| 239 | } |
| 240 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 241 | /*! \brief get multiple bits (based on numeric value) from current pos */ |
Max | e49af08 | 2016-01-22 16:46:56 +0100 | [diff] [blame] | 242 | int bitvec_get_uint(struct bitvec *bv, unsigned int num_bits) |
Andreas.Eversberg | 0ebd688 | 2010-05-09 09:36:54 +0000 | [diff] [blame] | 243 | { |
| 244 | int i; |
| 245 | unsigned int ui = 0; |
| 246 | |
| 247 | for (i = 0; i < num_bits; i++) { |
| 248 | int bit = bitvec_get_bit_pos(bv, bv->cur_bit); |
| 249 | if (bit < 0) |
| 250 | return bit; |
| 251 | if (bit) |
| 252 | ui |= (1 << (num_bits - i - 1)); |
| 253 | bv->cur_bit++; |
| 254 | } |
| 255 | |
| 256 | return ui; |
| 257 | } |
| 258 | |
Max | 0a59e98 | 2016-02-05 13:55:37 +0100 | [diff] [blame] | 259 | /*! \brief fill num_bits with \fill starting from the current position |
| 260 | * returns 0 on success, negative otherwise (out of vector boundary) |
| 261 | */ |
| 262 | int bitvec_fill(struct bitvec *bv, unsigned int num_bits, enum bit_value fill) |
| 263 | { |
| 264 | unsigned i, stop = bv->cur_bit + num_bits; |
| 265 | for (i = bv->cur_bit; i < stop; i++) |
| 266 | if (bitvec_set_bit(bv, fill) < 0) |
| 267 | return -EINVAL; |
| 268 | |
| 269 | return 0; |
| 270 | } |
| 271 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 272 | /*! \brief pad all remaining bits up to num_bits */ |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 273 | int bitvec_spare_padding(struct bitvec *bv, unsigned int up_to_bit) |
| 274 | { |
Max | 0a59e98 | 2016-02-05 13:55:37 +0100 | [diff] [blame] | 275 | int n = up_to_bit - bv->cur_bit + 1; |
| 276 | if (n < 1) |
| 277 | return 0; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 278 | |
Max | 0a59e98 | 2016-02-05 13:55:37 +0100 | [diff] [blame] | 279 | return bitvec_fill(bv, n, L); |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 280 | } |
Pablo Neira Ayuso | 36bdf2c | 2011-03-28 19:24:19 +0200 | [diff] [blame] | 281 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 282 | /*! \brief find first bit set in bit vector */ |
Pablo Neira Ayuso | 36bdf2c | 2011-03-28 19:24:19 +0200 | [diff] [blame] | 283 | int bitvec_find_bit_pos(const struct bitvec *bv, unsigned int n, |
| 284 | enum bit_value val) |
| 285 | { |
| 286 | unsigned int i; |
| 287 | |
| 288 | for (i = n; i < bv->data_len*8; i++) { |
| 289 | if (bitvec_get_bit_pos(bv, i) == val) |
| 290 | return i; |
| 291 | } |
| 292 | |
| 293 | return -1; |
| 294 | } |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 295 | |
Jacob Erlbeck | 5f349be | 2015-12-21 16:04:03 +0100 | [diff] [blame] | 296 | /*! \brief get multiple bytes from current pos |
| 297 | * Assumes MSB first encoding. |
| 298 | * \param[in] bv bit vector |
| 299 | * \param[in] bytes array |
| 300 | * \param[in] count number of bytes to copy |
| 301 | */ |
Max | e49af08 | 2016-01-22 16:46:56 +0100 | [diff] [blame] | 302 | int bitvec_get_bytes(struct bitvec *bv, uint8_t *bytes, unsigned int count) |
Jacob Erlbeck | 5f349be | 2015-12-21 16:04:03 +0100 | [diff] [blame] | 303 | { |
| 304 | int byte_offs = bytenum_from_bitnum(bv->cur_bit); |
| 305 | int bit_offs = bv->cur_bit % 8; |
| 306 | uint8_t c, last_c; |
| 307 | int i; |
| 308 | uint8_t *src; |
| 309 | |
| 310 | if (byte_offs + count + (bit_offs ? 1 : 0) > bv->data_len) |
| 311 | return -EINVAL; |
| 312 | |
| 313 | if (bit_offs == 0) { |
| 314 | memcpy(bytes, bv->data + byte_offs, count); |
| 315 | } else { |
| 316 | src = bv->data + byte_offs; |
| 317 | last_c = *(src++); |
| 318 | for (i = count; i > 0; i--) { |
| 319 | c = *(src++); |
| 320 | *(bytes++) = |
| 321 | (last_c << bit_offs) | |
| 322 | (c >> (8 - bit_offs)); |
| 323 | last_c = c; |
| 324 | } |
| 325 | } |
| 326 | |
| 327 | bv->cur_bit += count * 8; |
| 328 | return 0; |
| 329 | } |
| 330 | |
| 331 | /*! \brief set multiple bytes at current pos |
| 332 | * Assumes MSB first encoding. |
| 333 | * \param[in] bv bit vector |
| 334 | * \param[in] bytes array |
| 335 | * \param[in] count number of bytes to copy |
| 336 | */ |
Max | e49af08 | 2016-01-22 16:46:56 +0100 | [diff] [blame] | 337 | int bitvec_set_bytes(struct bitvec *bv, const uint8_t *bytes, unsigned int count) |
Jacob Erlbeck | 5f349be | 2015-12-21 16:04:03 +0100 | [diff] [blame] | 338 | { |
| 339 | int byte_offs = bytenum_from_bitnum(bv->cur_bit); |
| 340 | int bit_offs = bv->cur_bit % 8; |
| 341 | uint8_t c, last_c; |
| 342 | int i; |
| 343 | uint8_t *dst; |
| 344 | |
| 345 | if (byte_offs + count + (bit_offs ? 1 : 0) > bv->data_len) |
| 346 | return -EINVAL; |
| 347 | |
| 348 | if (bit_offs == 0) { |
| 349 | memcpy(bv->data + byte_offs, bytes, count); |
| 350 | } else if (count > 0) { |
| 351 | dst = bv->data + byte_offs; |
| 352 | /* Get lower bits of first dst byte */ |
| 353 | last_c = *dst >> (8 - bit_offs); |
| 354 | for (i = count; i > 0; i--) { |
| 355 | c = *(bytes++); |
| 356 | *(dst++) = |
| 357 | (last_c << (8 - bit_offs)) | |
| 358 | (c >> bit_offs); |
| 359 | last_c = c; |
| 360 | } |
| 361 | /* Overwrite lower bits of N+1 dst byte */ |
| 362 | *dst = (*dst & ((1 << (8 - bit_offs)) - 1)) | |
| 363 | (last_c << (8 - bit_offs)); |
| 364 | } |
| 365 | |
| 366 | bv->cur_bit += count * 8; |
| 367 | return 0; |
| 368 | } |
Max | a15f05f | 2016-01-26 10:43:15 +0100 | [diff] [blame] | 369 | |
| 370 | struct bitvec *bitvec_alloc(unsigned int size, TALLOC_CTX *ctx) |
| 371 | { |
| 372 | struct bitvec *bv = talloc_zero(ctx, struct bitvec); |
| 373 | if (!bv) |
| 374 | return NULL; |
| 375 | |
| 376 | bv->data = talloc_zero_array(bv, uint8_t, size); |
| 377 | if (!(bv->data)) { |
| 378 | talloc_free(bv); |
| 379 | return NULL; |
| 380 | } |
| 381 | |
| 382 | bv->data_len = size; |
| 383 | bv->cur_bit = 0; |
| 384 | return bv; |
| 385 | } |
| 386 | |
| 387 | void bitvec_free(struct bitvec *bv) |
| 388 | { |
| 389 | talloc_free(bv->data); |
| 390 | talloc_free(bv); |
| 391 | } |
| 392 | |
| 393 | unsigned int bitvec_pack(const struct bitvec *bv, uint8_t *buffer) |
| 394 | { |
| 395 | unsigned int i = 0; |
| 396 | for (i = 0; i < bv->data_len; i++) |
| 397 | buffer[i] = bv->data[i]; |
| 398 | |
| 399 | return i; |
| 400 | } |
| 401 | |
| 402 | unsigned int bitvec_unpack(struct bitvec *bv, const uint8_t *buffer) |
| 403 | { |
| 404 | unsigned int i = 0; |
| 405 | for (i = 0; i < bv->data_len; i++) |
| 406 | bv->data[i] = buffer[i]; |
| 407 | |
| 408 | return i; |
| 409 | } |
| 410 | |
| 411 | |
| 412 | int bitvec_unhex(struct bitvec *bv, const char *src) |
| 413 | { |
Holger Hans Peter Freyther | 2745b48 | 2016-01-27 17:08:02 +0100 | [diff] [blame] | 414 | unsigned i; |
Max | a15f05f | 2016-01-26 10:43:15 +0100 | [diff] [blame] | 415 | unsigned val; |
| 416 | unsigned write_index = 0; |
| 417 | unsigned digits = bv->data_len * 2; |
Holger Hans Peter Freyther | 2745b48 | 2016-01-27 17:08:02 +0100 | [diff] [blame] | 418 | |
| 419 | for (i = 0; i < digits; i++) { |
Max | a15f05f | 2016-01-26 10:43:15 +0100 | [diff] [blame] | 420 | if (sscanf(src + i, "%1x", &val) < 1) { |
| 421 | return 1; |
| 422 | } |
Holger Hans Peter Freyther | a9301a1 | 2016-01-30 10:54:43 +0100 | [diff] [blame] | 423 | bitvec_write_field(bv, &write_index, val, 4); |
Max | a15f05f | 2016-01-26 10:43:15 +0100 | [diff] [blame] | 424 | } |
| 425 | return 0; |
| 426 | } |
| 427 | |
Max | 912bc6f | 2016-01-28 12:07:12 +0100 | [diff] [blame] | 428 | /*! \brief read part of the vector |
| 429 | * \param[in] bv The boolean vector to work on |
Holger Hans Peter Freyther | a9301a1 | 2016-01-30 10:54:43 +0100 | [diff] [blame] | 430 | * \param[in,out] read_index Where reading supposed to start in the vector |
Max | 912bc6f | 2016-01-28 12:07:12 +0100 | [diff] [blame] | 431 | * \param[in] len How many bits to read from vector |
| 432 | * \returns read bits or negative value on error |
| 433 | */ |
Holger Hans Peter Freyther | a9301a1 | 2016-01-30 10:54:43 +0100 | [diff] [blame] | 434 | uint64_t bitvec_read_field(struct bitvec *bv, unsigned int *read_index, unsigned int len) |
Max | a15f05f | 2016-01-26 10:43:15 +0100 | [diff] [blame] | 435 | { |
| 436 | unsigned int i; |
| 437 | uint64_t ui = 0; |
Holger Hans Peter Freyther | a9301a1 | 2016-01-30 10:54:43 +0100 | [diff] [blame] | 438 | bv->cur_bit = *read_index; |
Max | a15f05f | 2016-01-26 10:43:15 +0100 | [diff] [blame] | 439 | |
| 440 | for (i = 0; i < len; i++) { |
| 441 | int bit = bitvec_get_bit_pos((const struct bitvec *)bv, bv->cur_bit); |
| 442 | if (bit < 0) |
| 443 | return bit; |
| 444 | if (bit) |
| 445 | ui |= ((uint64_t)1 << (len - i - 1)); |
| 446 | bv->cur_bit++; |
| 447 | } |
Holger Hans Peter Freyther | a9301a1 | 2016-01-30 10:54:43 +0100 | [diff] [blame] | 448 | *read_index += len; |
Max | a15f05f | 2016-01-26 10:43:15 +0100 | [diff] [blame] | 449 | return ui; |
| 450 | } |
| 451 | |
Max | 912bc6f | 2016-01-28 12:07:12 +0100 | [diff] [blame] | 452 | /*! \brief write into the vector |
| 453 | * \param[in] bv The boolean vector to work on |
Holger Hans Peter Freyther | a9301a1 | 2016-01-30 10:54:43 +0100 | [diff] [blame] | 454 | * \param[in,out] write_index Where writing supposed to start in the vector |
Max | 912bc6f | 2016-01-28 12:07:12 +0100 | [diff] [blame] | 455 | * \param[in] len How many bits to write |
| 456 | * \returns next write index or negative value on error |
| 457 | */ |
Holger Hans Peter Freyther | a9301a1 | 2016-01-30 10:54:43 +0100 | [diff] [blame] | 458 | int bitvec_write_field(struct bitvec *bv, unsigned int *write_index, uint64_t val, unsigned int len) |
Max | a15f05f | 2016-01-26 10:43:15 +0100 | [diff] [blame] | 459 | { |
| 460 | unsigned int i; |
| 461 | int rc; |
Holger Hans Peter Freyther | a9301a1 | 2016-01-30 10:54:43 +0100 | [diff] [blame] | 462 | bv->cur_bit = *write_index; |
Max | a15f05f | 2016-01-26 10:43:15 +0100 | [diff] [blame] | 463 | for (i = 0; i < len; i++) { |
| 464 | int bit = 0; |
| 465 | if (val & ((uint64_t)1 << (len - i - 1))) |
| 466 | bit = 1; |
| 467 | rc = bitvec_set_bit(bv, bit); |
| 468 | if (rc) |
| 469 | return rc; |
| 470 | } |
Holger Hans Peter Freyther | a9301a1 | 2016-01-30 10:54:43 +0100 | [diff] [blame] | 471 | *write_index += len; |
Max | a15f05f | 2016-01-26 10:43:15 +0100 | [diff] [blame] | 472 | return 0; |
| 473 | } |
| 474 | |
Max | 0a59e98 | 2016-02-05 13:55:37 +0100 | [diff] [blame] | 475 | /*! \brief convert enum to corresponding character */ |
| 476 | char bit_value_to_char(enum bit_value v) |
| 477 | { |
| 478 | switch (v) { |
| 479 | case ZERO: return '0'; |
| 480 | case ONE: return '1'; |
| 481 | case L: return 'L'; |
| 482 | case H: return 'H'; |
| 483 | default: abort(); |
| 484 | } |
| 485 | } |
| 486 | |
| 487 | /*! \brief prints bit vector to provided string |
| 488 | * It's caller's responsibility to ensure that we won't shoot him in the foot: |
| 489 | * the provided buffer should be at lest cur_bit + 1 bytes long |
| 490 | */ |
| 491 | void bitvec_to_string_r(const struct bitvec *bv, char *str) |
| 492 | { |
| 493 | unsigned i, pos = 0; |
| 494 | char *cur = str; |
| 495 | for (i = 0; i < bv->cur_bit; i++) { |
| 496 | if (0 == i % 8) |
| 497 | *cur++ = ' '; |
| 498 | *cur++ = bit_value_to_char(bitvec_get_bit_pos(bv, i)); |
| 499 | pos++; |
| 500 | } |
| 501 | *cur = 0; |
| 502 | } |
| 503 | |
| 504 | /* we assume that x have at least 1 non-b bit */ |
| 505 | static inline unsigned leading_bits(uint8_t x, bool b) |
| 506 | { |
| 507 | if (b) { |
| 508 | if (x < 0x80) return 0; |
| 509 | if (x < 0xC0) return 1; |
| 510 | if (x < 0xE0) return 2; |
| 511 | if (x < 0xF0) return 3; |
| 512 | if (x < 0xF8) return 4; |
| 513 | if (x < 0xFC) return 5; |
| 514 | if (x < 0xFE) return 6; |
| 515 | } else { |
| 516 | if (x > 0x7F) return 0; |
| 517 | if (x > 0x3F) return 1; |
| 518 | if (x > 0x1F) return 2; |
| 519 | if (x > 0xF) return 3; |
| 520 | if (x > 7) return 4; |
| 521 | if (x > 3) return 5; |
| 522 | if (x > 1) return 6; |
| 523 | } |
| 524 | return 7; |
| 525 | } |
| 526 | /*! \brief force bit vector to all 0 and current bit to the beginnig of the vector */ |
| 527 | void bitvec_zero(struct bitvec *bv) |
| 528 | { |
| 529 | bv->cur_bit = 0; |
| 530 | memset(bv->data, 0, bv->data_len); |
| 531 | } |
| 532 | |
| 533 | /*! \brief Return number (bits) of uninterrupted bit run in vector starting from the MSB |
| 534 | * \param[in] bv The boolean vector to work on |
| 535 | * \param[in] b The boolean, sequence of which is looked at from the vector start |
| 536 | * \returns Number of consecutive bits of \p b in \p bv |
| 537 | */ |
| 538 | unsigned bitvec_rl(const struct bitvec *bv, bool b) |
| 539 | { |
| 540 | unsigned i; |
| 541 | for (i = 0; i < (bv->cur_bit % 8 ? bv->cur_bit / 8 + 1 : bv->cur_bit / 8); i++) { |
| 542 | if ( (b ? 0xFF : 0) != bv->data[i]) |
| 543 | return i * 8 + leading_bits(bv->data[i], b); |
| 544 | } |
| 545 | |
| 546 | return bv->cur_bit; |
| 547 | } |
| 548 | |
| 549 | /*! \brief Shifts bitvec to the left, n MSB bits lost */ |
| 550 | void bitvec_shiftl(struct bitvec *bv, unsigned n) |
| 551 | { |
| 552 | if (0 == n) |
| 553 | return; |
| 554 | if (n >= bv->cur_bit) { |
| 555 | bitvec_zero(bv); |
| 556 | return; |
| 557 | } |
| 558 | |
| 559 | memmove(bv->data, bv->data + n / 8, bv->data_len - n / 8); |
| 560 | |
| 561 | uint8_t tmp[2]; |
| 562 | unsigned i; |
| 563 | for (i = 0; i < bv->data_len - 2; i++) { |
| 564 | uint16_t t = osmo_load16be(bv->data + i); |
| 565 | osmo_store16be(t << (n % 8), &tmp); |
| 566 | bv->data[i] = tmp[0]; |
| 567 | } |
| 568 | |
| 569 | bv->data[bv->data_len - 1] <<= (n % 8); |
| 570 | bv->cur_bit -= n; |
| 571 | } |
| 572 | |
Sylvain Munaut | dca7d2c | 2012-04-18 21:53:23 +0200 | [diff] [blame] | 573 | /*! @} */ |