1 files changed, 254 insertions, 0 deletions
diff --git a/locale/hash.c b/locale/hash.c
new file mode 100644
index 0000000000..75cb77f882
--- /dev/null
+++ b/locale/hash.c
@@ -0,0 +1,254 @@
+/* Copyright (C) 1995 Free Software Foundation, Inc.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <obstack.h>
+#include <stdlib.h>
+#include <string.h>
+#include <values.h>
+
+#include "hash.h"
+
+#define obstack_chunk_alloc xmalloc
+#define obstack_chunk_free free
+
+void *xmalloc (size_t n);
+
+typedef struct hash_entry
+  {
+    int used;
+    char *key;
+    void *data;
+    struct hash_entry *next;
+  }
+hash_entry;
+
+/* Prototypes for local functions.  */
+static size_t lookup (hash_table *htab, const char *key, size_t keylen,
+		      unsigned long hval);
+static unsigned long compute_hashval(const char *key, size_t keylen);
+static unsigned long next_prime(unsigned long seed);
+static int is_prime(unsigned long candidate);
+
+
+int
+init_hash(hash_table *htab, unsigned long init_size)
+{
+  /* We need the size to be a prime.  */
+  init_size = next_prime (init_size);
+
+  /* Initialize the data structure.  */
+  htab->size = init_size;
+  htab->filled = 0;
+  htab->first = NULL;
+  htab->table = calloc (init_size + 1, sizeof (hash_entry));
+  obstack_init (&htab->mem_pool);
+
+  return htab->table == NULL;
+}
+
+
+int
+delete_hash(hash_table *htab)
+{
+  free (htab->table);
+  obstack_free (&htab->mem_pool, NULL);
+  return 0;
+}
+
+
+int
+insert_entry (hash_table *htab, const char *key, size_t keylen, void *data)
+{
+  unsigned long hval = compute_hashval (key, keylen);
+  hash_entry *table = (hash_entry *) htab->table;
+  size_t idx = lookup (htab, key, keylen, hval);
+
+  if (table[idx].used)
+    /* We don't want to overwrite the old value.  */
+    return 1;
+  else
+    {
+      hash_entry **p;
+
+      /* An empty bucket has been found.  */
+      table[idx].used = hval;
+      table[idx].key = obstack_copy0 (&htab->mem_pool, key, keylen);
+      table[idx].data = data;
+
+      /* List the new value in the ordered list.  */
+      for (p = (hash_entry **) &htab->first; *p != NULL && (*p)->data < data;
+	   p = &(*p)->next);
+      if (*p == NULL || (*p)->data > data)
+	/* Insert new value in the list.  */
+	{
+	  table[idx].next = *p;
+	  *p = &table[idx];
+	}
+
+      ++htab->filled;
+      if (100 * htab->filled > 90 * htab->size)
+	{
+	  /* Resize the table.  */
+	  unsigned long old_size = htab->size;
+
+	  htab->size = next_prime (htab->size * 2);
+	  htab->filled = 0;
+	  htab->first = NULL;
+	  htab->table = calloc (htab->size, sizeof (hash_entry));
+
+	  for (idx = 1; idx <= old_size; ++idx)
+	    if (table[idx].used)
+	      insert_entry (htab, table[idx].key, strlen(table[idx].key),
+			    table[idx].data);
+
+	  free (table);
+	}
+      return 0;
+    }
+  /* NOTREACHED */
+}
+
+
+int
+find_entry (hash_table *htab, const char *key, size_t keylen, void **result)
+{
+  hash_entry *table = (hash_entry *) htab->table;
+  size_t idx = lookup (htab, key, keylen, compute_hashval (key, keylen));
+  int retval;
+
+  retval = table[idx].used;
+  *result = retval ? table[idx].data : NULL;
+
+  return retval;
+}
+
+
+int
+iterate_table (hash_table *htab, void **ptr, void **result)
+{
+  if (*ptr == NULL)
+    *ptr = (void *) htab->first;
+  else
+    {
+      *ptr = (void *) (((hash_entry *) *ptr)->next);
+      if (*ptr == NULL)
+	return 0;
+    }
+
+  *result = ((hash_entry *) *ptr)->data;
+  return 1;
+}
+
+
+static size_t
+lookup (hash_table *htab, const char *key, size_t keylen, unsigned long hval)
+{
+  unsigned long hash;
+  size_t idx;
+  hash_entry *table = (hash_entry *) htab->table;
+
+  /* First hash function: simply take the modul but prevent zero.  */
+  hash = 1 + hval % htab->size;
+
+  idx = hash;
+  
+  if (table[idx].used)
+    {
+      if (table[idx].used == hval && table[idx].key[keylen] == '\0'
+	  && strncmp (key, table[idx].key, keylen) == 0)
+	return idx;
+
+      /* Second hash function as suggested in [Knuth].  */
+      hash = 1 + hash % (htab->size - 2);
+
+      do
+	{
+	  if (idx <= hash)
+	    idx = htab->size + idx - hash;
+	  else
+	    idx -= hash;
+
+	  /* If entry is found use it.  */
+	  if (table[idx].used == hval && table[idx].key[keylen] == '\0'
+	      && strncmp (key, table[idx].key, keylen) == 0)
+	    return idx;
+	}
+      while (table[idx].used);
+    }
+  return idx;
+}
+
+
+static unsigned long
+compute_hashval(const char *key, size_t keylen)
+{
+  size_t cnt;
+  unsigned long hval, g;
+  /* Compute the hash value for the given string.  */
+  cnt = 0;
+  hval = keylen;
+  while (cnt < keylen)
+    {
+      hval <<= 4;
+      hval += key[cnt++];
+      g = hval & (0xf << (LONGBITS - 4));
+      if (g != 0)
+	{
+	  hval ^= g >> (LONGBITS - 8);
+	  hval ^= g;
+	}
+    }
+  return hval;
+}
+
+
+static unsigned long
+next_prime(unsigned long seed)
+{
+  /* Make it definitely odd.  */
+  seed |= 1;
+
+  while (!is_prime (seed))
+    seed += 2;
+
+  return seed;
+}
+
+
+static int
+is_prime(unsigned long candidate)
+{
+  /* No even number and none less than 10 will be passwd here.  */
+  unsigned long div = 3;
+  unsigned long sq = div * div;
+
+  while (sq < candidate && candidate % div != 0)
+    {
+      ++div;
+      sq += 4 * div;
+      ++div;
+    }
+
+  return candidate % div != 0;
+}
+
+/*
+ * Local Variables:
+ *  mode:c
+ *  c-basic-offset:2
+ * End:
+ */