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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-15 19:44:05 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-15 19:44:05 +0000
commitd318611dd6f23fcfedd50e9b9e24620b102ba96a (patch)
tree8b9eef82ca40fdd5a8deeabf07572074c236095d /src/include/itable.h
parentInitial commit. (diff)
downloadgroff-upstream.tar.xz
groff-upstream.zip
Adding upstream version 1.23.0.upstream/1.23.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/include/itable.h')
-rw-r--r--src/include/itable.h193
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diff --git a/src/include/itable.h b/src/include/itable.h
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+/* Copyright (C) 1989-2020 Free Software Foundation, Inc.
+ Written by James Clark (jjc@jclark.com)
+
+This file is part of groff.
+
+groff is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+groff is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <assert.h>
+
+// 'class ITABLE(T)' is the type of a hash table mapping an integer (int >= 0)
+// to an object of type T.
+//
+// 'struct IASSOC(T)' is the type of a association (pair) between an integer
+// (int >= 0) and an object of type T.
+//
+// 'class ITABLE_ITERATOR(T)' is the type of an iterator iterating through a
+// 'class ITABLE(T)'.
+//
+// Nowadays one would use templates for this; this code predates the addition
+// of templates to C++.
+#define ITABLE(T) T ## _itable
+#define IASSOC(T) T ## _iassoc
+#define ITABLE_ITERATOR(T) T ## _itable_iterator
+
+// ptable.h declares this too
+#ifndef NEXT_PTABLE_SIZE_DEFINED
+# define NEXT_PTABLE_SIZE_DEFINED
+extern unsigned next_ptable_size(unsigned); // Return the first suitable
+ // hash table size greater than the given
+ // value.
+#endif
+
+// Declare the types 'class ITABLE(T)', 'struct IASSOC(T)', and 'class
+// ITABLE_ITERATOR(T)' for the type 'T'.
+#define declare_itable(T) \
+ \
+struct IASSOC(T) { \
+ int key; \
+ T *val; \
+ IASSOC(T)(); \
+}; \
+ \
+class ITABLE(T); \
+ \
+class ITABLE_ITERATOR(T) { \
+ ITABLE(T) *p; \
+ unsigned i; \
+public: \
+ ITABLE_ITERATOR(T)(ITABLE(T) *); /* Initialize an iterator running \
+ through the given table. */ \
+ int next(int *, T **); /* Fetch the next pair, store the key \
+ and value in arg1 and arg2, \
+ respectively, and return 1. If \
+ there is no more pair in the \
+ table, return 0. */ \
+}; \
+ \
+class ITABLE(T) { \
+ IASSOC(T) *v; \
+ unsigned size; \
+ unsigned used; \
+ enum { \
+ FULL_NUM = 2, \
+ FULL_DEN = 3, \
+ INITIAL_SIZE = 17 \
+ }; \
+public: \
+ ITABLE(T)(); /* Create an empty table. */ \
+ ~ITABLE(T)(); /* Delete a table, including its \
+ values. */ \
+ void define(int, T *); /* Define the value (arg2) for a key \
+ (arg1). */ \
+ T *lookup(int); /* Return a pointer to the value of \
+ the given key, if found in the \
+ table, or NULL otherwise. */ \
+ friend class ITABLE_ITERATOR(T); \
+};
+
+
+// Values must be allocated by the caller (always using new[], not new)
+// and are freed by ITABLE.
+
+// Define the implementations of the members of the types 'class ITABLE(T)',
+// 'struct IASSOC(T)', 'class ITABLE_ITERATOR(T)' for the type 'T'.
+#define implement_itable(T) \
+ \
+IASSOC(T)::IASSOC(T)() \
+: key(-1), val(0) \
+{ \
+} \
+ \
+ITABLE(T)::ITABLE(T)() \
+{ \
+ v = new IASSOC(T)[size = INITIAL_SIZE]; \
+ used = 0; \
+} \
+ \
+ITABLE(T)::~ITABLE(T)() \
+{ \
+ for (unsigned i = 0; i < size; i++) \
+ delete[] v[i].val; \
+ delete[] v; \
+} \
+ \
+void ITABLE(T)::define(int key, T *val) \
+{ \
+ assert(key >= 0); \
+ unsigned int h = (unsigned int)(key); \
+ unsigned n; \
+ for (n = unsigned(h % size); \
+ v[n].key >= 0; \
+ n = (n == 0 ? size - 1 : n - 1)) \
+ if (v[n].key == key) { \
+ delete[] v[n].val; \
+ v[n].val = val; \
+ return; \
+ } \
+ if (val == 0) \
+ return; \
+ if (used*FULL_DEN >= size*FULL_NUM) { \
+ IASSOC(T) *oldv = v; \
+ unsigned old_size = size; \
+ size = next_ptable_size(size); \
+ v = new IASSOC(T)[size]; \
+ for (unsigned i = 0; i < old_size; i++) \
+ if (oldv[i].key >= 0) { \
+ if (oldv[i].val != 0) { \
+ unsigned j; \
+ for (j = (unsigned int)(oldv[i].key) % size; \
+ v[j].key >= 0; \
+ j = (j == 0 ? size - 1 : j - 1)) \
+ ; \
+ v[j].key = oldv[i].key; \
+ v[j].val = oldv[i].val; \
+ } \
+ } \
+ for (n = unsigned(h % size); \
+ v[n].key >= 0; \
+ n = (n == 0 ? size - 1 : n - 1)) \
+ ; \
+ delete[] oldv; \
+ } \
+ v[n].key = key; \
+ v[n].val = val; \
+ used++; \
+} \
+ \
+T *ITABLE(T)::lookup(int key) \
+{ \
+ assert(key >= 0); \
+ for (unsigned n = (unsigned int)key % size; \
+ v[n].key >= 0; \
+ n = (n == 0 ? size - 1 : n - 1)) \
+ if (v[n].key == key) \
+ return v[n].val; \
+ return 0; \
+} \
+ \
+ITABLE_ITERATOR(T)::ITABLE_ITERATOR(T)(ITABLE(T) *t) \
+: p(t), i(0) \
+{ \
+} \
+ \
+int ITABLE_ITERATOR(T)::next(int *keyp, T **valp) \
+{ \
+ unsigned size = p->size; \
+ IASSOC(T) *v = p->v; \
+ for (; i < size; i++) \
+ if (v[i].key >= 0) { \
+ *keyp = v[i].key; \
+ *valp = v[i].val; \
+ i++; \
+ return 1; \
+ } \
+ return 0; \
+}
+
+// Local Variables:
+// fill-column: 72
+// mode: C++
+// End:
+// vim: set cindent noexpandtab shiftwidth=2 textwidth=72: