[map] First try at implementing an integer-to-integer hashmap
Fully untested.
diff --git a/src/hb-map.cc b/src/hb-map.cc
new file mode 100644
index 0000000..4f50828
--- /dev/null
+++ b/src/hb-map.cc
@@ -0,0 +1,279 @@
+/*
+ * Copyright © 2018 Google, Inc.
+ *
+ * This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#include "hb-map-private.hh"
+
+
+/* Public API */
+
+
+/**
+ * hb_map_create: (Xconstructor)
+ *
+ * Return value: (transfer full):
+ *
+ * Since: REPLACEME
+ **/
+hb_map_t *
+hb_map_create (void)
+{
+ hb_map_t *map;
+
+ if (!(map = hb_object_create<hb_map_t> ()))
+ return hb_map_get_empty ();
+
+ map->init_shallow ();
+
+ return map;
+}
+
+static const hb_map_t _hb_map_nil = {
+ HB_OBJECT_HEADER_STATIC,
+ true, /* in_error */
+ 0, /* occupancy */
+ 0, /* mask */
+ 0, /* prime */
+ nullptr /* items */
+};
+
+/**
+ * hb_map_get_empty:
+ *
+ * Return value: (transfer full):
+ *
+ * Since: REPLACEME
+ **/
+hb_map_t *
+hb_map_get_empty (void)
+{
+ return const_cast<hb_map_t *> (&_hb_map_nil);
+}
+
+/**
+ * hb_map_reference: (skip)
+ * @map: a map.
+ *
+ * Return value: (transfer full):
+ *
+ * Since: REPLACEME
+ **/
+hb_map_t *
+hb_map_reference (hb_map_t *map)
+{
+ return hb_object_reference (map);
+}
+
+/**
+ * hb_map_destroy: (skip)
+ * @map: a map.
+ *
+ * Since: REPLACEME
+ **/
+void
+hb_map_destroy (hb_map_t *map)
+{
+ if (!hb_object_destroy (map)) return;
+
+ map->fini_shallow ();
+
+ free (map);
+}
+
+/**
+ * hb_map_set_user_data: (skip)
+ * @map: a map.
+ * @key:
+ * @data:
+ * @destroy:
+ * @replace:
+ *
+ * Return value:
+ *
+ * Since: REPLACEME
+ **/
+hb_bool_t
+hb_map_set_user_data (hb_map_t *map,
+ hb_user_data_key_t *key,
+ void * data,
+ hb_destroy_func_t destroy,
+ hb_bool_t replace)
+{
+ return hb_object_set_user_data (map, key, data, destroy, replace);
+}
+
+/**
+ * hb_map_get_user_data: (skip)
+ * @map: a map.
+ * @key:
+ *
+ * Return value: (transfer none):
+ *
+ * Since: REPLACEME
+ **/
+void *
+hb_map_get_user_data (hb_map_t *map,
+ hb_user_data_key_t *key)
+{
+ return hb_object_get_user_data (map, key);
+}
+
+
+/**
+ * hb_map_allocation_successful:
+ * @map: a map.
+ *
+ *
+ *
+ * Return value:
+ *
+ * Since: REPLACEME
+ **/
+hb_bool_t
+hb_map_allocation_successful (const hb_map_t *map)
+{
+ return !map->in_error;
+}
+
+
+/**
+ * hb_map_set:
+ * @map: a map.
+ * @key:
+ * @value:
+ *
+ *
+ *
+ * Return value:
+ *
+ * Since: REPLACEME
+ **/
+void
+hb_map_set (hb_map_t *map,
+ hb_codepoint_t key,
+ hb_codepoint_t value)
+{
+ map->set (key, value);
+}
+
+/**
+ * hb_map_get:
+ * @map: a map.
+ * @key:
+ *
+ *
+ *
+ * Since: REPLACEME
+ **/
+hb_codepoint_t
+hb_map_get (const hb_map_t *map,
+ hb_codepoint_t key)
+{
+ return map->get (key);
+}
+
+/**
+ * hb_map_del:
+ * @map: a map.
+ * @codepoint:
+ *
+ *
+ *
+ * Since: REPLACEME
+ **/
+void
+hb_map_del (hb_map_t *map,
+ hb_codepoint_t key)
+{
+ map->del (key);
+}
+
+/**
+ * hb_map_has:
+ * @map: a map.
+ * @codepoint:
+ *
+ *
+ *
+ * Since: REPLACEME
+ **/
+bool
+hb_map_has (const hb_map_t *map,
+ hb_codepoint_t key)
+{
+ return map->has (key);
+}
+
+
+/* Following comment and table copied from glib. */
+/* Each table size has an associated prime modulo (the first prime
+ * lower than the table size) used to find the initial bucket. Probing
+ * then works modulo 2^n. The prime modulo is necessary to get a
+ * good distribution with poor hash functions.
+ */
+static const unsigned int prime_mod [] =
+{
+ 1, /* For 1 << 0 */
+ 2,
+ 3,
+ 7,
+ 13,
+ 31,
+ 61,
+ 127,
+ 251,
+ 509,
+ 1021,
+ 2039,
+ 4093,
+ 8191,
+ 16381,
+ 32749,
+ 65521, /* For 1 << 16 */
+ 131071,
+ 262139,
+ 524287,
+ 1048573,
+ 2097143,
+ 4194301,
+ 8388593,
+ 16777213,
+ 33554393,
+ 67108859,
+ 134217689,
+ 268435399,
+ 536870909,
+ 1073741789,
+ 2147483647 /* For 1 << 31 */
+};
+
+unsigned int
+hb_map_t::prime_for (unsigned int shift)
+{
+ if (unlikely (shift >= ARRAY_LENGTH (prime_mod)))
+ return prime_mod[ARRAY_LENGTH (prime_mod) -1];
+
+ return prime_mod[shift];
+}
