add missing new header

src/util/strings.h

@@ -0,0 +1,52 @@
+/*
+Copyright (c) 1998-2015, Enno Rehling <enno@eressea.de>
+Katja Zedel <katze@felidae.kn-bremen.de
+Christian Schlittchen <corwin@amber.kn-bremen.de>
+
+Permission to use, copy, modify, and/or 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.
+**/
+
+#ifndef STRINGS_H
+#define STRINGS_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+    extern unsigned int hashstring(const char *s);
+    extern const char *escape_string(const char *str, char *buffer,
+        size_t len);
+    extern unsigned int jenkins_hash(unsigned int a);
+    extern unsigned int wang_hash(unsigned int a);
+
+    /* benchmark for units:
+     * JENKINS_HASH: 5.25 misses/hit (with good cache behavior)
+     * WANG_HASH:    5.33 misses/hit (with good cache behavior)
+     * KNUTH_HASH:   1.93 misses/hit (with bad cache behavior)
+     * CF_HASH:      fucking awful!
+     */
+#define KNUTH_HASH1(a, m) ((a) % m)
+#define KNUTH_HASH2(a, m) (m - 2 - a % (m-2))
+#define CF_HASH1(a, m) ((a) % m)
+#define CF_HASH2(a, m) (8 - ((a) & 7))
+#define JENKINS_HASH1(a, m) (jenkins_hash(a) % m)
+#define JENKINS_HASH2(a, m) 1
+#define WANG_HASH1(a, m) (wang_hash(a) % m)
+#define WANG_HASH2(a, m) 1
+
+#define HASH1 JENKINS_HASH1
+#define HASH2 JENKINS_HASH2
+
+#ifdef __cplusplus
+}
+#endif
+#endif                          /* STRINGS_H */