[multimap] Add a multimap datastructure

src/Makefile.am

@@ -368,6 +368,7 @@ COMPILED_TESTS = \
 	test-iter \
 	test-machinery \
 	test-map \
+	test-multimap \
 	test-number \
 	test-ot-tag \
 	test-priority-queue \
@@ -407,6 +408,10 @@ test_map_SOURCES = test-map.cc hb-static.cc
 test_map_CPPFLAGS = $(COMPILED_TESTS_CPPFLAGS)
 test_map_LDADD = $(COMPILED_TESTS_LDADD)
 
+test_multimap_SOURCES = test-multimap.cc hb-static.cc
+test_multimap_CPPFLAGS = $(COMPILED_TESTS_CPPFLAGS)
+test_multimap_LDADD = $(COMPILED_TESTS_LDADD)
+
 test_number_SOURCES = test-number.cc hb-number.cc
 test_number_CPPFLAGS = $(COMPILED_TESTS_CPPFLAGS)
 test_number_LDADD = $(COMPILED_TESTS_LDADD)

src/Makefile.sources

@@ -52,6 +52,7 @@ HB_BASE_sources = \
 	hb-map.hh \
 	hb-meta.hh \
 	hb-ms-feature-ranges.hh \
+	hb-multimap.hh \
 	hb-mutex.hh \
 	hb-null.hh \
 	hb-number.cc \

src/hb-multimap.hh

@@ -0,0 +1,92 @@
+/*
+ * Copyright © 2022  Behdad Esfahbod
+ *
+ *  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.
+ */
+
+#ifndef HB_MULTIMAP_HH
+#define HB_MULTIMAP_HH
+
+#include "hb.hh"
+#include "hb-map.hh"
+#include "hb-vector.hh"
+
+
+/*
+ * hb_multimap_t
+ */
+
+struct hb_multimap_t
+{
+  void add (hb_codepoint_t k, hb_codepoint_t v)
+  {
+    hb_codepoint_t *i;
+    if (multiples_indices.has (k, &i))
+    {
+      multiples_values[*i].push (v);
+      return;
+    }
+
+    hb_codepoint_t *old_v;
+    if (singulars.has (k, &old_v))
+    {
+      hb_codepoint_t old = *old_v;
+      singulars.del (k);
+
+      multiples_indices.set (k, multiples_values.length);
+      auto *vec = multiples_values.push ();
+
+      vec->push (old);
+      vec->push (v);
+
+      return;
+    }
+
+    singulars.set (k, v);
+  }
+
+  hb_array_t<hb_codepoint_t> get (hb_codepoint_t k)
+  {
+    hb_codepoint_t *v;
+    if (singulars.has (k, &v))
+      return hb_array (v, 1);
+
+    hb_codepoint_t *i;
+    if (multiples_indices.has (k, &i))
+      return multiples_values[*i].as_array ();
+
+    return hb_array_t<hb_codepoint_t> ();
+  }
+
+  bool in_error () const
+  {
+    return singulars.in_error () || multiples_indices.in_error () || multiples_values.in_error ();
+  }
+
+  protected:
+  hb_map_t singulars;
+  hb_map_t multiples_indices;
+  hb_vector_t<hb_vector_t<hb_codepoint_t>> multiples_values;
+};
+
+
+
+#endif /* HB_MULTIMAP_HH */

src/meson.build

@@ -56,6 +56,7 @@ hb_base_sources = files(
   'hb-map.hh',
   'hb-meta.hh',
   'hb-ms-feature-ranges.hh',
+  'hb-multimap.hh',
   'hb-mutex.hh',
   'hb-null.hh',
   'hb-number.cc',
@@ -580,6 +581,7 @@ if get_option('tests').enabled()
     'test-iter': ['test-iter.cc', 'hb-static.cc'],
     'test-machinery': ['test-machinery.cc', 'hb-static.cc'],
     'test-map': ['test-map.cc', 'hb-static.cc'],
+    'test-multimap': ['test-multimap.cc', 'hb-static.cc'],
     'test-number': ['test-number.cc', 'hb-number.cc'],
     'test-ot-tag': ['hb-ot-tag.cc'],
     'test-priority-queue': ['test-priority-queue.cc', 'hb-static.cc'],

src/test-multimap.cc

@@ -0,0 +1,50 @@
+/*
+ * Copyright © 2022  Behdad Esfahbod
+ *
+ *  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.
+ */
+
+#include "hb.hh"
+#include "hb-multimap.hh"
+
+int
+main (int argc, char **argv)
+{
+  hb_multimap_t m;
+
+  assert (m.get (10).length == 0);
+
+  m.add (10, 11);
+  assert (m.get (10).length == 1);
+
+  m.add (10, 12);
+  assert (m.get (10).length == 2);
+
+  m.add (10, 13);
+  assert (m.get (10).length == 3);
+  assert (m.get (10)[0] == 11);
+  assert (m.get (10)[1] == 12);
+  assert (m.get (10)[2] == 13);
+
+  assert (m.get (11).length == 0);
+
+  return 0;
+}