/* * ks_index.c * ---------- * Keystore index API. This is internal within libhal. * * Copyright (c) 2016-2017, NORDUnet A/S All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * - Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of the NORDUnet nor the names of its contributors may * be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include "hal.h" #include "hal_internal.h" #include "ks.h" /* * Find a block in the index, return true (found) or false (not found). * "where" indicates the name's position, or the position of the first free block. * * NB: This does NOT return a block number, it returns an index into * ks->index[]. */ static int ks_find(const hal_ks_t * const ks, const hal_uuid_t * const uuid, const int * const hint, int *where) { if (ks == NULL || ks->index == NULL || ks->names == NULL || uuid == NULL || where == NULL) return 0; if (hint != NULL && *hint >= 0 && *hint < (int)ks->used && hal_uuid_cmp(uuid, &ks->names[ks->index[*hint]]) == 0) { *where = *hint; return 1; } int lo = -1; int hi = ks->used; for (;;) { int m = (lo + hi) / 2; if (hi == 0 || m == lo) { *where = hi; return 0; } const int cmp = hal_uuid_cmp(uuid, &ks->names[ks->index[m]]); if (cmp < 0) hi = m; else if (cmp > 0) lo = m; else { *where = m; return 1; } } } /* * Heapsort the index. We only need to do this on setup, for other * operations we're just inserting or deleting a single entry in an * already-ordered array, which is just a search problem. If we were * really crunched for space, we could use an insertion sort here, but * heapsort is easy and works well with data already in place. */ static inline hal_error_t ks_heapsift(hal_ks_t *ks, int parent, const int end) { if (ks == NULL || ks->index == NULL || ks->names == NULL || parent < 0 || end < parent) return HAL_ERROR_IMPOSSIBLE; for (;;) { const int left_child = parent * 2 + 1; const int right_child = parent * 2 + 2; int biggest = parent; if (left_child <= end && hal_uuid_cmp(&ks->names[ks->index[biggest]], &ks->names[ks->index[left_child]]) < 0) biggest = left_child; if (right_child <= end && hal_uuid_cmp(&ks->names[ks->index[biggest]], &ks->names[ks->index[right_child]]) < 0) biggest = right_child; if (biggest == parent) return HAL_OK; const uint16_t tmp = ks->index[biggest]; ks->index[biggest] = ks->index[parent]; ks->index[parent] = tmp; parent = biggest; } } hal_error_t hal_ks_index_heapsort(hal_ks_t *ks) { if (ks == NULL || ks->index == NULL || ks->names == NULL) return HAL_ERROR_IMPOSSIBLE; if (ks->used < 2) return HAL_OK; hal_error_t err; for (int i = (ks->used - 2) / 2; i >= 0; i--) if ((err = ks_heapsift(ks, i, ks->used - 1)) != HAL_OK) return err; for (int i = ks->used - 1; i > 0; i--) { const uint16_t tmp = ks->index[i]; ks->index[i] = ks->index[0]; ks->index[0] = tmp; if ((err = ks_heapsift(ks, 0, i - 1)) != HAL_OK) return err; } return HAL_OK; } /* * Perform a consistency check on the index. */ #define fsck(_ks) \ do { hal_error_t _err = hal_ks_index_fsck(_ks); if (_err != HAL_OK) return _err; } while (0) hal_error_t hal_ks_index_fsck(hal_ks_t *ks) { if (ks == NULL || ks->index == NULL || ks->names == NULL || ks->size == 0 || ks->used > ks->size) return HAL_ERROR_BAD_ARGUMENTS; for (unsigned i = 1; i < ks->used; i++) if (hal_uuid_cmp(&ks->names[ks->index[i - 1]], &ks->names[ks->index[i]]) >= 0) return HAL_ERROR_KS_INDEX_UUID_MISORDERED; return HAL_OK; } /* * Find a single block by name. */ hal_error_t hal_ks_index_find(hal_ks_t *ks, const hal_uuid_t * const name, unsigned *blockno, int *hint) { if (ks == NULL || ks->index == NULL || ks->names == NULL || ks->size == 0 || ks->used > ks->size || name == NULL) return HAL_ERROR_BAD_ARGUMENTS; int where; fsck(ks); int ok = ks_find(ks, name, hint, &where); if (blockno != NULL) *blockno = ks->index[where]; if (hint != NULL) *hint = where; return ok ? HAL_OK : HAL_ERROR_KEY_NOT_FOUND; } /* * Add a single block to the index. */ hal_error_t hal_ks_index_add(hal_ks_t *ks, const hal_uuid_t * const name, unsigned *blockno, int *hint) { if (ks == NULL || ks->index == NULL || ks->names == NULL || ks->size == 0 || ks->used > ks->size || name == NULL) return HAL_ERROR_BAD_ARGUMENTS; if (ks->used == ks->size) return HAL_ERROR_NO_KEY_INDEX_SLOTS; int where; fsck(ks); if (ks_find(ks, name, hint, &where)) return HAL_ERROR_KEY_NAME_IN_USE; /* * Grab first block on free list, which makes room to slide the * index up by one slot so we can insert the new block number. */ const size_t len = (ks->used - where) * sizeof(*ks->index); const uint16_t b = ks->index[ks->used++]; memmove(&ks->index[where + 1], &ks->index[where], len); ks->index[where] = b; ks->names[b] = *name; if (blockno != NULL) *blockno = b; if (hint != NULL) *hint = where; fsck(ks); return HAL_OK; } /* * Delete a single block from the index. */ hal_error_t hal_ks_index_delete(hal_ks_t *ks, const hal_uuid_t * const name, unsigned *blockno, int *hint) { if (ks == NULL || ks->index == NULL || ks->names == NULL || ks->size == 0 || ks->used > ks->size || name == NULL) return HAL_ERROR_BAD_ARGUMENTS; int where; fsck(ks); if (ks->used == 0 || !ks_find(ks, name, hint, &where)) return HAL_ERROR_KEY_NOT_FOUND; /* * Free the block and stuff it at the end of the free list. */ const size_t len = (ks->size - where - 1) * sizeof(*ks->index); const uint16_t b = ks->index[where]; memmove(&ks->index[where], &ks->index[where + 1], len); ks->index[ks->size - 1] = b; ks->used--; memset(&ks->names[b], 0, sizeof(ks->names[b])); if (blockno != NULL) *blockno = b; if (hint != NULL) *hint = where; fsck(ks); return HAL_OK; } /* * Replace a single block with a new one, return new block number. * Name of block does not change. This is an optimization of a delete * immediately followed by an add for the same name. */ hal_error_t hal_ks_index_replace(hal_ks_t *ks, const hal_uuid_t * const name, unsigned *blockno, int *hint) { if (ks == NULL || ks->index == NULL || ks->names == NULL || ks->size == 0 || ks->used > ks->size || name == NULL) return HAL_ERROR_BAD_ARGUMENTS; if (ks->used == ks->size) return HAL_ERROR_NO_KEY_INDEX_SLOTS; int where; fsck(ks); if (ks->used == 0 || !ks_find(ks, name, hint, &where)) return HAL_ERROR_KEY_NOT_FOUND; /* * Grab first block from free list, slide free list down, put old * block at end of free list and replace old block with new block. */ const size_t len = (ks->size - ks->used - 1) * sizeof(*ks->index); const uint16_t b1 = ks->index[where]; const uint16_t b2 = ks->index[ks->used]; memmove(&ks->index[ks->used], &ks->index[ks->used + 1], len); ks->index[ks->size - 1] = b1; ks->index[where] = b2; ks->names[b2] = *name; memset(&ks->names[b1], 0, sizeof(ks->names[b1])); if (blockno != NULL) *blockno = b2; if (hint != NULL) *hint = where; fsck(ks); return HAL_OK; } /* * Local variables: * indent-tabs-mode: nil * End: */ ='#n185'>185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298