inicial

1 files changed, 224 insertions, 0 deletions

diff --git a/backend/dvi/mdvi-lib/hash.c b/backend/dvi/mdvi-lib/hash.c
new file mode 100644
index 00000000..d359e3c8
--- /dev/null
+++ b/backend/dvi/mdvi-lib/hash.c
@@ -0,0 +1,224 @@
+/*
+ * Copyright (C) 2000, Matias Atria
+ *
+ * This program 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <config.h>
+#include "mdvi.h"
+
+/* simple hash tables for MDVI */
+
+
+struct _DviHashBucket {
+	DviHashBucket *next;
+	DviHashKey	key;
+	Ulong	hvalue;
+	void	*data;
+};
+
+static Ulong hash_string(DviHashKey key)
+{
+	Uchar	*p;
+	Ulong	h, g;
+	
+	for(h = 0, p = (Uchar *)key; *p; p++) {
+		h = (h << 4UL) + *p;
+		if((g = h & 0xf0000000L) != 0) {
+			h ^= (g >> 24UL);
+			h ^= g;
+		}
+	}
+		
+	return h;
+}
+
+static int hash_compare(DviHashKey k1, DviHashKey k2)
+{
+	return strcmp((char *)k1, (char *)k2);
+}
+
+void	mdvi_hash_init(DviHashTable *hash)
+{
+	hash->buckets = NULL;
+	hash->nbucks  = 0;
+	hash->nkeys   = 0;
+	hash->hash_func = NULL;
+	hash->hash_comp = NULL;
+	hash->hash_free = NULL;
+}
+
+void	mdvi_hash_create(DviHashTable *hash, int size)
+{
+	int	i;
+	
+	hash->nbucks = size;
+	hash->buckets = xnalloc(DviHashBucket *, size);
+	for(i = 0; i < size; i++)
+		hash->buckets[i] = NULL;
+	hash->hash_func = hash_string;
+	hash->hash_comp = hash_compare;
+	hash->hash_free = NULL;
+	hash->nkeys = 0;
+}
+
+static DviHashBucket *hash_find(DviHashTable *hash, DviHashKey key)
+{
+	Ulong	hval;
+	DviHashBucket *buck;
+	
+	hval = (hash->hash_func(key) % hash->nbucks);
+	
+	for(buck = hash->buckets[hval]; buck; buck = buck->next)
+		if(hash->hash_comp(buck->key, key) == 0)
+			break;
+	return buck;
+}
+
+/* Neither keys nor data are duplicated */
+int	mdvi_hash_add(DviHashTable *hash, DviHashKey key, void *data, int rep)
+{
+	DviHashBucket *buck = NULL;
+	Ulong	hval;
+	
+	if(rep != MDVI_HASH_UNCHECKED) {
+		buck = hash_find(hash, key);
+		if(buck != NULL) {
+			if(buck->data == data)
+				return 0;
+			if(rep == MDVI_HASH_UNIQUE)
+				return -1;
+			if(hash->hash_free != NULL)
+				hash->hash_free(buck->key, buck->data);
+		}
+	}
+	if(buck == NULL) {
+		buck = xalloc(DviHashBucket);
+		buck->hvalue = hash->hash_func(key);
+		hval = (buck->hvalue % hash->nbucks);
+		buck->next = hash->buckets[hval];
+		hash->buckets[hval] = buck;
+		hash->nkeys++;
+	}
+	
+	/* save key and data */
+	buck->key = key;
+	buck->data = data;
+	
+	return 0;
+}
+
+void	*mdvi_hash_lookup(DviHashTable *hash, DviHashKey key)
+{
+	DviHashBucket *buck = hash_find(hash, key);
+
+	return buck ? buck->data : NULL;
+}
+
+static DviHashBucket *hash_remove(DviHashTable *hash, DviHashKey key)
+{
+	DviHashBucket *buck, *last;
+	Ulong	hval;
+	
+	hval = hash->hash_func(key);
+	hval %= hash->nbucks;
+	
+	for(last = NULL, buck = hash->buckets[hval]; buck; buck = buck->next) {
+		if(hash->hash_comp(buck->key, key) == 0)
+			break;
+		last = buck;
+	}
+	if(buck == NULL)
+		return NULL;
+	if(last)
+		last->next = buck->next;
+	else
+		hash->buckets[hval] = buck->next;
+	hash->nkeys--;
+	return buck;
+}
+
+void	*mdvi_hash_remove(DviHashTable *hash, DviHashKey key)
+{
+	DviHashBucket *buck = hash_remove(hash, key);
+	void	*data = NULL;
+
+	if(buck) {
+		data = buck->data;
+		mdvi_free(buck);
+	}
+	return data;
+}
+
+void	*mdvi_hash_remove_ptr(DviHashTable *hash, DviHashKey key)
+{
+	DviHashBucket *buck, *last;
+	Ulong	hval;
+	void	*ptr;
+	
+	hval = hash->hash_func(key);
+	hval %= hash->nbucks;
+	
+	for(last = NULL, buck = hash->buckets[hval]; buck; buck = buck->next) {
+		if(buck->key == key)
+			break;
+		last = buck;
+	}
+	if(buck == NULL)
+		return NULL;
+	if(last)
+		last->next = buck->next;
+	else
+		hash->buckets[hval] = buck->next;
+	hash->nkeys--;
+	/* destroy the bucket */
+	ptr = buck->data;
+	mdvi_free(buck);
+	return ptr;
+}
+
+int	mdvi_hash_destroy_key(DviHashTable *hash, DviHashKey key)
+{
+	DviHashBucket *buck = hash_remove(hash, key);
+	
+	if(buck == NULL)
+		return -1;
+	if(hash->hash_free)
+		hash->hash_free(buck->key, buck->data);
+	mdvi_free(buck);
+	return 0;	
+}
+
+void	mdvi_hash_reset(DviHashTable *hash, int reuse)
+{
+	int	i;
+	DviHashBucket *buck;
+	
+	/* remove all keys in the hash table */
+	for(i = 0; i < hash->nbucks; i++) {
+		for(; (buck = hash->buckets[i]); ) {
+			hash->buckets[i] = buck->next;
+			if(hash->hash_free)
+				hash->hash_free(buck->key, buck->data);
+			mdvi_free(buck);
+		}
+	}
+	hash->nkeys = 0;
+	if(!reuse && hash->buckets) {
+		mdvi_free(hash->buckets);
+		hash->buckets = NULL;
+		hash->nbucks = 0;
+	} /* otherwise, it is left empty, ready to be reused */
+}