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+/*
+ * ks_index.c
+ * ----------
+ * Keystore index API. This is internal within libhal.
+ *
+ * Copyright (c) 2016, 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 <string.h>
+#include <assert.h>
+
+#include "hal.h"
+#include "hal_internal.h"
+
+/*
+ * Compare two hal_ks_name_t objects.
+ */
+
+static inline int ks_name_cmp(const hal_ks_name_t * const name1, const hal_ks_name_t * const name2)
+{
+ assert(name1 != NULL && name2 != NULL);
+
+ int cmp = hal_uuid_cmp(&name1->name, &name2->name);
+
+ if (cmp == 0)
+ cmp = ((int) name1->chunk) - ((int) name2->chunk);
+
+ return cmp;
+}
+
+/*
+ * Return value indicates whether the name is present in the index.
+ * "where" indicates the name's position whether present or not.
+ *
+ * NB: This does NOT return a block number, it returns an index into
+ * ksi->index[].
+ */
+
+static int ks_find(const hal_ks_index_t * const ksi,
+ const hal_uuid_t * const uuid,
+ const uint8_t chunk,
+ const int * const hint,
+ int *where)
+{
+ assert(ksi != NULL && ksi->index != NULL && ksi->names != NULL && uuid != NULL && where != NULL);
+
+ const hal_ks_name_t name = { *uuid, chunk };
+
+ if (hint != NULL && *hint >= 0 && *hint < ksi->used &&
+ ks_name_cmp(&name, &ksi->names[ksi->index[*hint]]) == 0) {
+ *where = *hint;
+ return 1;
+ }
+
+ int lo = -1;
+ int hi = ksi->used;
+
+ for (;;) {
+ int m = (lo + hi) / 2;
+ if (hi == 0 || m == lo) {
+ *where = hi;
+ return 0;
+ }
+ const int cmp = ks_name_cmp(&name, &ksi->names[ksi->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 void ks_heapsift(hal_ks_index_t *ksi, int parent, const int end)
+{
+ assert(ksi != NULL && ksi->index != NULL && ksi->names != NULL &&
+ parent >= 0 && end >= parent);
+ for (;;) {
+ const int left_child = parent * 2 + 1;
+ const int right_child = parent * 2 + 2;
+ int biggest = parent;
+ if (left_child <= end && ks_name_cmp(&ksi->names[ksi->index[biggest]],
+ &ksi->names[ksi->index[left_child]]) < 0)
+ biggest = left_child;
+ if (right_child <= end && ks_name_cmp(&ksi->names[ksi->index[biggest]],
+ &ksi->names[ksi->index[right_child]]) < 0)
+ biggest = right_child;
+ if (biggest == parent)
+ return;
+ const uint16_t tmp = ksi->index[biggest];
+ ksi->index[biggest] = ksi->index[parent];
+ ksi->index[parent] = tmp;
+ parent = biggest;
+ }
+}
+
+static inline void ks_heapsort(hal_ks_index_t *ksi)
+{
+ assert(ksi != NULL && ksi->index != NULL && ksi->names != NULL);
+ if (ksi->used < 2)
+ return;
+ for (int i = (ksi->used - 2) / 2; i >= 0; i--)
+ ks_heapsift(ksi, i, ksi->used - 1);
+ for (int i = ksi->used - 1; i > 0; i--) {
+ const uint16_t tmp = ksi->index[i];
+ ksi->index[i] = ksi->index[0];
+ ksi->index[0] = tmp;
+ ks_heapsift(ksi, 0, i - 1);
+ }
+}
+
+#define fsck(_ksi) \
+ do { hal_error_t _err = hal_ks_index_fsck(_ksi); if (_err != HAL_OK) return _err; } while (0)
+
+
+hal_error_t hal_ks_index_fsck(hal_ks_index_t *ksi)
+{
+ if (ksi == NULL || ksi->index == NULL || ksi->names == NULL ||
+ ksi->size == 0 || ksi->used > ksi->size)
+ return HAL_ERROR_BAD_ARGUMENTS;
+
+ for (int i = 0; i < ksi->used; i++) {
+
+ const int cmp = i == 0 ? -1 : hal_uuid_cmp(&ksi->names[ksi->index[i - 1]].name,
+ &ksi->names[ksi->index[i ]].name);
+
+ const uint8_t prev_chunk = i == 0 ? 0 : ksi->names[ksi->index[i - 1]].chunk;
+ const uint8_t cur_chunk = ksi->names[ksi->index[i ]].chunk;
+
+ if (cmp > 0)
+ return HAL_ERROR_KSI_INDEX_UUID_MISORDERED;
+
+ if (cur_chunk > 0 && cmp != 0)
+ return HAL_ERROR_KSI_INDEX_CHUNK_ORPHANED;
+
+ if (cur_chunk > 0 && prev_chunk + 1 < cur_chunk)
+ return HAL_ERROR_KSI_INDEX_CHUNK_MISSING;
+
+ if (cur_chunk > 0 && prev_chunk + 1 > cur_chunk)
+ return HAL_ERROR_KSI_INDEX_CHUNK_OVERLAPS;
+ }
+
+ return HAL_OK;
+}
+
+hal_error_t hal_ks_index_setup(hal_ks_index_t *ksi)
+{
+ if (ksi == NULL || ksi->index == NULL || ksi->names == NULL ||
+ ksi->size == 0 || ksi->used > ksi->size)
+ return HAL_ERROR_BAD_ARGUMENTS;
+
+ /*
+ * Only setup task we have at the moment is sorting the index.
+ */
+
+ ks_heapsort(ksi);
+
+ /*
+ * One might think we should fsck here, but errors in the index
+ * at this point probably relate to errors in the supplied data,
+ * which only the driver knows how to clean up.
+ */
+
+ return HAL_OK;
+}
+
+hal_error_t hal_ks_index_find(hal_ks_index_t *ksi,
+ const hal_uuid_t * const name,
+ const unsigned chunk,
+ unsigned *blockno,
+ int *hint)
+{
+ if (ksi == NULL || ksi->index == NULL || ksi->names == NULL ||
+ ksi->size == 0 || ksi->used > ksi->size || name == NULL)
+ return HAL_ERROR_BAD_ARGUMENTS;
+
+ int where;
+
+ fsck(ksi);
+
+ int ok = ks_find(ksi, name, chunk, hint, &where);
+
+ if (blockno != NULL)
+ *blockno = ksi->index[where];
+
+ if (hint != NULL)
+ *hint = where;
+
+ return ok ? HAL_OK : HAL_ERROR_KEY_NOT_FOUND;
+}
+
+hal_error_t hal_ks_index_find_range(hal_ks_index_t *ksi,
+ const hal_uuid_t * const name,
+ const unsigned max_blocks,
+ unsigned *n_blocks,
+ unsigned *blocknos,
+ int *hint,
+ const int strict)
+{
+ if (ksi == NULL || ksi->index == NULL || ksi->names == NULL ||
+ ksi->size == 0 || ksi->used > ksi->size || name == NULL)
+ return HAL_ERROR_BAD_ARGUMENTS;
+
+ int where;
+
+ fsck(ksi);
+
+ if (!ks_find(ksi, name, 0, hint, &where))
+ return HAL_ERROR_KEY_NOT_FOUND;
+
+ int n = 0;
+
+ for (int i = where; i < ksi->used && !hal_uuid_cmp(name, &ksi->names[ksi->index[i]].name); i++) {
+ if (strict && n != ksi->names[ksi->index[i]].chunk)
+ return HAL_ERROR_IMPOSSIBLE;
+ if (blocknos != NULL && n < max_blocks)
+ blocknos[n] = ksi->index[i];
+ n++;
+ }
+
+ if (n_blocks != NULL)
+ *n_blocks = n;
+
+ if (hint != NULL)
+ *hint = where;
+
+ if (blocknos != NULL && n > max_blocks)
+ return HAL_ERROR_RESULT_TOO_LONG;
+
+ return HAL_OK;
+}
+
+hal_error_t hal_ks_index_add(hal_ks_index_t *ksi,
+ const hal_uuid_t * const name,
+ const unsigned chunk,
+ unsigned *blockno,
+ int *hint)
+{
+ if (ksi == NULL || ksi->index == NULL || ksi->names == NULL ||
+ ksi->size == 0 || ksi->used > ksi->size || name == NULL)
+ return HAL_ERROR_BAD_ARGUMENTS;
+
+ if (ksi->used == ksi->size)
+ return HAL_ERROR_NO_KEY_INDEX_SLOTS;
+
+ int where;
+
+ fsck(ksi);
+
+ if (ks_find(ksi, name, chunk, 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 = (ksi->used - where) * sizeof(*ksi->index);
+ const uint16_t b = ksi->index[ksi->used++];
+ memmove(&ksi->index[where + 1], &ksi->index[where], len);
+ ksi->index[where] = b;
+ ksi->names[b].name = *name;
+ ksi->names[b].chunk = chunk;
+
+ if (blockno != NULL)
+ *blockno = b;
+
+ if (hint != NULL)
+ *hint = where;
+
+ fsck(ksi);
+
+ return HAL_OK;
+}
+
+hal_error_t hal_ks_index_delete(hal_ks_index_t *ksi,
+ const hal_uuid_t * const name,
+ const unsigned chunk,
+ unsigned *blockno,
+ int *hint)
+{
+ if (ksi == NULL || ksi->index == NULL || ksi->names == NULL ||
+ ksi->size == 0 || ksi->used > ksi->size || name == NULL)
+ return HAL_ERROR_BAD_ARGUMENTS;
+
+ int where;
+
+ fsck(ksi);
+
+ if (ksi->used == 0 || !ks_find(ksi, name, chunk, 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 = (ksi->size - where - 1) * sizeof(*ksi->index);
+ const uint16_t b = ksi->index[where];
+ memmove(&ksi->index[where], &ksi->index[where + 1], len);
+ ksi->index[ksi->size - 1] = b;
+ ksi->used--;
+ memset(&ksi->names[b], 0, sizeof(ksi->names[b]));
+
+ if (blockno != NULL)
+ *blockno = b;
+
+ if (hint != NULL)
+ *hint = where;
+
+ fsck(ksi);
+
+ return HAL_OK;
+}
+
+hal_error_t hal_ks_index_delete_range(hal_ks_index_t *ksi,
+ const hal_uuid_t * const name,
+ const unsigned max_blocks,
+ unsigned *n_blocks,
+ unsigned *blocknos,
+ int *hint)
+{
+ if (ksi == NULL || ksi->index == NULL || ksi->names == NULL ||
+ ksi->size == 0 || ksi->used > ksi->size || name == NULL)
+ return HAL_ERROR_BAD_ARGUMENTS;
+
+ int where;
+
+ fsck(ksi);
+
+ if (ksi->used == 0 || !ks_find(ksi, name, 0, hint, &where))
+ return HAL_ERROR_KEY_NOT_FOUND;
+
+ int n = 0;
+
+ for (int i = where; i < ksi->used && !hal_uuid_cmp(name, &ksi->names[ksi->index[i]].name); i++) {
+ if (n != ksi->names[ksi->index[i]].chunk)
+ return HAL_ERROR_IMPOSSIBLE;
+ if (blocknos != NULL && n < max_blocks)
+ blocknos[n] = ksi->index[i];
+ n++;
+ }
+
+ if (n_blocks != NULL)
+ *n_blocks = n;
+
+ /*
+ * Free the blocks and stuff them at the end of the free list.
+ */
+
+ if (blocknos != NULL) {
+ if (n > max_blocks)
+ return HAL_ERROR_RESULT_TOO_LONG;
+ const size_t len = (ksi->size - where - n) * sizeof(*ksi->index);
+ memmove(&ksi->index[where], &ksi->index[where + n], len);
+ ksi->used -= n;
+ for (int i = 0; i < n; i++) {
+ ksi->index[ksi->size - n + i] = blocknos[i];
+ memset(&ksi->names[blocknos[i]], 0, sizeof(ksi->names[blocknos[i]]));
+ }
+ where = -1;
+ }
+
+ if (hint != NULL)
+ *hint = where;
+
+ fsck(ksi);
+
+ return HAL_OK;
+}
+
+hal_error_t hal_ks_index_replace(hal_ks_index_t *ksi,
+ const hal_uuid_t * const name,
+ const unsigned chunk,
+ unsigned *blockno,
+ int *hint)
+{
+ if (ksi == NULL || ksi->index == NULL || ksi->names == NULL ||
+ ksi->size == 0 || ksi->used > ksi->size || name == NULL)
+ return HAL_ERROR_BAD_ARGUMENTS;
+
+ if (ksi->used == ksi->size)
+ return HAL_ERROR_NO_KEY_INDEX_SLOTS;
+
+ int where;
+
+ fsck(ksi);
+
+ if (ksi->used == 0 || !ks_find(ksi, name, chunk, 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 = (ksi->size - ksi->used - 1) * sizeof(*ksi->index);
+ const uint16_t b1 = ksi->index[where];
+ const uint16_t b2 = ksi->index[ksi->used];
+ memmove(&ksi->index[ksi->used], &ksi->index[ksi->used + 1], len);
+ ksi->index[ksi->size - 1] = b1;
+ ksi->index[where] = b2;
+ ksi->names[b2].name = *name;
+ ksi->names[b2].chunk = chunk;
+ memset(&ksi->names[b1], 0, sizeof(ksi->names[b1]));
+
+ if (blockno != NULL)
+ *blockno = b2;
+
+ if (hint != NULL)
+ *hint = where;
+
+ fsck(ksi);
+
+ return HAL_OK;
+}
+
+/*
+ * Local variables:
+ * indent-tabs-mode: nil
+ * End:
+ */
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