* the reference buffer.
*/
for (i = 0; i < hsize; i++) {
- if (hash_count[i] < HASH_LIMIT)
+ int acc;
+
+ if (hash_count[i] <= HASH_LIMIT)
continue;
+
+ /* We leave exactly HASH_LIMIT entries in the bucket */
+ entries -= hash_count[i] - HASH_LIMIT;
+
entry = hash[i];
+ acc = 0;
+
+ /*
+ * Assume that this loop is gone through exactly
+ * HASH_LIMIT times and is entered and left with
+ * acc==0. So the first statement in the loop
+ * contributes (hash_count[i]-HASH_LIMIT)*HASH_LIMIT
+ * to the accumulator, and the inner loop consequently
+ * is run (hash_count[i]-HASH_LIMIT) times, removing
+ * one element from the list each time. Since acc
+ * balances out to 0 at the final run, the inner loop
+ * body can't be left with entry==NULL. So we indeed
+ * encounter entry==NULL in the outer loop only.
+ */
do {
- struct unpacked_index_entry *keep = entry;
- int skip = hash_count[i] / HASH_LIMIT;
- do {
- --entries;
- entry = entry->next;
- } while(--skip && entry);
- ++entries;
- keep->next = entry;
- } while(entry);
+ acc += hash_count[i] - HASH_LIMIT;
+ if (acc > 0) {
+ struct unpacked_index_entry *keep = entry;
+ do {
+ entry = entry->next;
+ acc -= HASH_LIMIT;
+ } while (acc > 0);
+ keep->next = entry->next;
+ }
+ entry = entry->next;
+ } while (entry);
}
free(hash_count);
- /* Now create the packed index in array form rather than
- * linked lists */
-
+ /*
+ * Now create the packed index in array form
+ * rather than linked lists.
+ */
memsize = sizeof(*index)
+ sizeof(*packed_hash) * (hsize+1)
+ sizeof(*packed_entry) * entries;
-
mem = malloc(memsize);
-
if (!mem) {
free(hash);
return NULL;
index->src_size = bufsize;
index->hash_mask = hmask;
- mem = index + 1;
+ mem = index->hash;
packed_hash = mem;
mem = packed_hash + (hsize+1);
packed_entry = mem;
- /* Coalesce all entries belonging to one linked list into
- * consecutive array entries */
-
for (i = 0; i < hsize; i++) {
+ /*
+ * Coalesce all entries belonging to one linked list
+ * into consecutive array entries.
+ */
packed_hash[i] = packed_entry;
for (entry = hash[i]; entry; entry = entry->next)
*packed_entry++ = entry->entry;
}
- /* Sentinel value to indicate the length of the last hash
- * bucket */
-
+ /* Sentinel value to indicate the length of the last hash bucket */
packed_hash[hsize] = packed_entry;
+
assert(packed_entry - (struct index_entry *)mem == entries);
free(hash);