[map] First try at implementing an integer-to-integer hashmap

Fully untested.

src/Makefile.sources

@@ -14,6 +14,8 @@ HB_BASE_sources = \
 	hb-face.cc \
 	hb-font-private.hh \
 	hb-font.cc \
+	hb-map-private.hh \
+	hb-map.cc \
 	hb-mutex-private.hh \
 	hb-object-private.hh \
 	hb-open-file-private.hh \
@@ -69,6 +71,7 @@ HB_BASE_headers = \
 	hb-deprecated.h \
 	hb-face.h \
 	hb-font.h \
+	hb-map.h \
 	hb-set.h \
 	hb-shape.h \
 	hb-shape-plan.h \

src/hb-map-private.hh

+/*
+ * Copyright © 2012,2017  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
+ */
+
+#ifndef HB_MAP_PRIVATE_HH
+#define HB_MAP_PRIVATE_HH
+
+#include "hb-private.hh"
+#include "hb-object-private.hh"
+
+
+template <typename T>
+inline uint32_t Hash (const T &v)
+{
+  /* Knuth's multiplicative method: */
+  return (uint32_t) v * 2654435761u;
+}
+
+
+/*
+ * hb_map_t
+ */
+
+struct hb_map_t
+{
+  struct item_t
+  {
+    hb_codepoint_t key;
+    hb_codepoint_t value;
+
+    inline bool is_unused (void) const { return key == INVALID; }
+    inline bool is_tombstone (void) const { return key != INVALID && value == INVALID; }
+  };
+
+  hb_object_header_t header;
+  ASSERT_POD ();
+  bool in_error;
+  unsigned int occupancy; /* Including tombstones. */
+  unsigned int mask;
+  unsigned int prime;
+  item_t *items;
+
+  inline void init_shallow (void)
+  {
+    in_error = false;
+    occupancy = 0;
+    mask = 0;
+    prime = 0;
+    items = nullptr;
+  }
+  inline void init (void)
+  {
+    hb_object_init (this);
+    init_shallow ();
+  }
+  inline void fini_shallow (void)
+  {
+    free (items);
+  }
+  inline void fini (void)
+  {
+    hb_object_fini (this);
+    fini_shallow ();
+  }
+
+  inline bool resize (void)
+  {
+    if (unlikely (in_error)) return false;
+
+    unsigned int power = _hb_bit_storage (occupancy * 2 + 8) - 1;
+    unsigned int new_size = 1u << power;
+    item_t *new_items = (item_t *) malloc ((size_t) new_size * sizeof (item_t));
+    if (unlikely (!new_items))
+    {
+      in_error = true;
+      return false;
+    }
+    memset (new_items, 0xFF, (size_t) new_size * sizeof (item_t));
+
+    unsigned int old_size = mask + 1;
+    item_t *old_items = items;
+
+    /* Switch to new, empty, array. */
+    occupancy = 0;
+    mask = new_size - 1;
+    prime = prime_for (power);
+    items = new_items;
+
+    /* Insert back old items. */
+    for (unsigned int i = 0; i < old_size; i++)
+      if (old_items[i].key != INVALID && old_items[i].value != INVALID)
+        set (old_items[i].key, old_items[i].value);
+
+    free (old_items);
+
+    return true;
+  }
+
+  inline void set (hb_codepoint_t key, hb_codepoint_t value)
+  {
+    if (unlikely (in_error)) return;
+    if ((occupancy + occupancy / 2) > mask && !resize ()) return;
+    unsigned int i = bucket_for (key);
+    if (items[i].key != key)
+    {
+      if (items[i].key == INVALID && key != INVALID)
+	occupancy++;
+      items[i].key = key;
+    }
+    items[i].value = value;
+  }
+  inline hb_codepoint_t get (hb_codepoint_t key) const
+  {
+    if (unlikely (in_error)) return INVALID;
+    if (unlikely (!items)) return INVALID;
+    unsigned int i = bucket_for (key);
+    return items[i].key == key ? items[i].value : INVALID;
+  }
+
+  inline void del (hb_codepoint_t key)
+  {
+    if (unlikely (in_error)) return;
+    if (unlikely (!items)) return;
+    unsigned int i = bucket_for (key);
+    items[i].value = INVALID;
+  }
+  inline bool has (hb_codepoint_t key) const
+  {
+    return get (key) != INVALID;
+  }
+
+  static const hb_codepoint_t INVALID = HB_MAP_VALUE_INVALID;
+
+  protected:
+  static HB_INTERNAL unsigned int prime_for (unsigned int shift);
+
+  unsigned int bucket_for (hb_codepoint_t key) const
+  {
+    unsigned int i = Hash (key) % prime;
+    unsigned int step = 0;
+    unsigned int tombstone = INVALID;
+    while (!items[i].is_unused ())
+    {
+      if (items[i].key == key)
+        return i;
+      if (tombstone == INVALID && items[i].is_tombstone ())
+        tombstone = i;
+      i = (i + ++step) & mask;
+    }
+    return tombstone == INVALID ? i : tombstone;
+  }
+
+  private:
+  HB_DISALLOW_COPY_AND_ASSIGN (hb_map_t);
+};
+
+
+#endif /* HB_MAP_PRIVATE_HH */

src/hb-map.cc

+/*
+ * 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];
+}

src/hb-map.h

+/*
+ * 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
+ */
+
+#ifndef HB_H_IN
+#error "Include <hb.h> instead."
+#endif
+
+#ifndef HB_MAP_H
+#define HB_MAP_H
+
+#include "hb-common.h"
+
+HB_BEGIN_DECLS
+
+
+/*
+ * Since: REPLACEME
+ */
+#define HB_MAP_VALUE_INVALID ((hb_codepoint_t) -1)
+
+typedef struct hb_map_t hb_map_t;
+
+
+HB_EXTERN hb_map_t *
+hb_map_create (void);
+
+HB_EXTERN hb_map_t *
+hb_map_get_empty (void);
+
+HB_EXTERN hb_map_t *
+hb_map_reference (hb_map_t *map);
+
+HB_EXTERN void
+hb_map_destroy (hb_map_t *map);
+
+HB_EXTERN 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);
+
+HB_EXTERN void *
+hb_map_get_user_data (hb_map_t           *map,
+		      hb_user_data_key_t *key);
+
+
+/* Returns false if allocation has failed before */
+HB_EXTERN hb_bool_t
+hb_map_allocation_successful (const hb_map_t *map);
+
+/*
+ HB_EXTERN void
+ hb_map_clear (hb_map_t *map);
+
+ HB_EXTERN hb_bool_t
+ hb_map_is_empty (const hb_map_t *map);
+
+ HB_EXTERN unsigned int
+ hb_set_get_population (const hb_set_t *set);
+
+ HB_EXTERN hb_bool_t
+ hb_map_is_equal (const hb_map_t *map,
+		 const hb_map_t *other);
+*/
+
+HB_EXTERN void
+hb_map_set (hb_map_t       *map,
+	    hb_codepoint_t  key,
+	    hb_codepoint_t  value);
+
+HB_EXTERN hb_codepoint_t
+hb_map_get (const hb_map_t *map,
+	    hb_codepoint_t  key);
+
+HB_EXTERN void
+hb_map_del (hb_map_t       *map,
+	    hb_codepoint_t  key);
+
+HB_EXTERN bool
+hb_map_has (const hb_map_t *map,
+	    hb_codepoint_t  key);
+
+
+HB_END_DECLS
+
+#endif /* HB_MAP_H */

src/hb.h

@@ -38,6 +38,7 @@
 #include "hb-deprecated.h"
 #include "hb-face.h"
 #include "hb-font.h"
+#include "hb-map.h"
 #include "hb-set.h"
 #include "hb-shape.h"
 #include "hb-shape-plan.h"