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-rw-r--r--usr.bin/m4/lib/ohash_do.c111
1 files changed, 111 insertions, 0 deletions
diff --git a/usr.bin/m4/lib/ohash_do.c b/usr.bin/m4/lib/ohash_do.c
new file mode 100644
index 0000000..2b8467d
--- /dev/null
+++ b/usr.bin/m4/lib/ohash_do.c
@@ -0,0 +1,111 @@
+/* $OpenBSD: ohash_do.c,v 1.4 2004/06/22 20:00:16 espie Exp $ */
+/* ex:ts=8 sw=4:
+ */
+
+/* Copyright (c) 1999, 2004 Marc Espie <espie@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "ohash_int.h"
+
+static void ohash_resize(struct ohash *);
+
+static void
+ohash_resize(struct ohash *h)
+{
+ struct _ohash_record *n;
+ unsigned int ns, j;
+ unsigned int i, incr;
+
+ if (4 * h->deleted < h->total)
+ ns = h->size << 1;
+ else if (3 * h->deleted > 2 * h->total)
+ ns = h->size >> 1;
+ else
+ ns = h->size;
+ if (ns < MINSIZE)
+ ns = MINSIZE;
+#ifdef STATS_HASH
+ STAT_HASH_EXPAND++;
+ STAT_HASH_SIZE += ns - h->size;
+#endif
+ n = (h->info.halloc)(sizeof(struct _ohash_record) * ns, h->info.data);
+ if (!n)
+ return;
+
+ for (j = 0; j < h->size; j++) {
+ if (h->t[j].p != NULL && h->t[j].p != DELETED) {
+ i = h->t[j].hv % ns;
+ incr = ((h->t[j].hv % (ns - 2)) & ~1) + 1;
+ while (n[i].p != NULL) {
+ i += incr;
+ if (i >= ns)
+ i -= ns;
+ }
+ n[i].hv = h->t[j].hv;
+ n[i].p = h->t[j].p;
+ }
+ }
+ (h->info.hfree)(h->t, sizeof(struct _ohash_record) * h->size,
+ h->info.data);
+ h->t = n;
+ h->size = ns;
+ h->total -= h->deleted;
+ h->deleted = 0;
+}
+
+void *
+ohash_remove(struct ohash *h, unsigned int i)
+{
+ void *result = __UNCONST(h->t[i].p);
+
+ if (result == NULL || result == DELETED)
+ return NULL;
+
+#ifdef STATS_HASH
+ STAT_HASH_ENTRIES--;
+#endif
+ h->t[i].p = DELETED;
+ h->deleted++;
+ if (h->deleted >= MINDELETED && 4 * h->deleted > h->total)
+ ohash_resize(h);
+ return result;
+}
+
+void *
+ohash_find(struct ohash *h, unsigned int i)
+{
+ if (h->t[i].p == DELETED)
+ return NULL;
+ else
+ return __UNCONST(h->t[i].p);
+}
+
+void *
+ohash_insert(struct ohash *h, unsigned int i, void *p)
+{
+#ifdef STATS_HASH
+ STAT_HASH_ENTRIES++;
+#endif
+ if (h->t[i].p == DELETED) {
+ h->deleted--;
+ h->t[i].p = p;
+ } else {
+ h->t[i].p = p;
+ /* Arbitrary resize boundary. Tweak if not efficient enough. */
+ if (++h->total * 4 > h->size * 3)
+ ohash_resize(h);
+ }
+ return p;
+}