Added hash-based stat cache code from Ying Chen.

Jeremy.
(This used to be commit b62a1bd6328f5894ae1a2fef3ef6fc66304ade52)

3 files changed, 86 insertions, 0 deletions

diff --git a/source3/include/hash.h b/source3/include/hash.h
new file mode 100644
index 0000000000..2de7031855
--- /dev/null
+++ b/source3/include/hash.h
@@ -0,0 +1,75 @@
+/* 
+   Unix SMB/Netbios implementation.
+   Version 2.0
+
+   Copyright (C) Ying Chen 2000.
+   
+   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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#ifndef	_HASH_H_
+#define	_HASH_H_
+
+#define MAX_HASH_TABLE_SIZE    32768
+#define HASH_TABLE_INCREMENT  2
+
+typedef int (*compare_function)(char *, char *);
+typedef int (*hash_function)(int, char *);
+
+/*
+ * lru_link: links the node to the LRU list.
+ * hash_elem: the pointer to the element that is tied onto the link.
+ */
+typedef struct lru_node {
+        ubi_dlNode lru_link;
+        void *hash_elem;
+} lru_node;
+
+/* 
+ * bucket_link: link the hash element to the bucket chain that it belongs to.
+ * lru_link: this element ties the hash element to the lru list. 
+ * bucket: a pointer to the hash bucket that this element belongs to.
+ * value: a pointer to the hash element content. It can be anything.
+ * key: stores the string key. The hash_element is always allocated with
+ * more memory space than the structure shown below to accomodate the space
+ * used for the whole string. But the memory is always appended at the 
+ * end of the structure, so keep "key" at the end of the structure.
+ * Don't move it.
+ */
+typedef struct hash_element {
+        ubi_dlNode	bucket_link;          
+        lru_node    lru_link;
+        ubi_dlList	*bucket;
+        void	*value;		
+        char key[1];	
+} hash_element;
+
+/*
+ * buckets: a list of buckets, implemented as a dLinkList. 
+ * lru_chain: the lru list of all the hash elements. 
+ * num_elements: the # of elements in the hash table.
+ * size: the hash table size.
+ * comp_func: the compare function used during hash key comparisons.
+ */
+
+typedef struct hash_table {
+        ubi_dlList      *buckets;
+        ubi_dlList      lru_chain;     
+        int     num_elements;	
+        int     size;
+        compare_function        comp_func; 
+} hash_table;
+
+#endif /* _HASH_H_ */
diff --git a/source3/include/includes.h b/source3/include/includes.h
index a872c1d306..a049b725c4 100644
--- a/source3/include/includes.h
+++ b/source3/include/includes.h
@@ -619,6 +619,7 @@ extern int errno;
 #include "../tdb/tdb.h"
 #include "talloc.h"
 #include "interfaces.h"
+#include "hash.h"
 
 #ifdef HAVE_FNMATCH
 #include <fnmatch.h>
diff --git a/source3/include/proto.h b/source3/include/proto.h
index 03fc5b1353..205031a2a8 100644
--- a/source3/include/proto.h
+++ b/source3/include/proto.h
@@ -97,6 +97,15 @@ void generate_random_buffer( unsigned char *out, int len, BOOL re_seed);
 
 char *getsmbpass(char *prompt)    ;
 
+/*The following definitions come from  lib/hash.c  */
+
+BOOL hash_table_init(hash_table *table, int num_buckets, compare_function compare_func);
+int string_hash(int hash_size, const char *key);
+hash_element *hash_lookup(hash_table *table, char *key);
+hash_element *hash_insert(hash_table *table, char *value, char *key);
+void hash_remove(hash_table *table, hash_element *hash_elem);
+void hash_clear(hash_table *table);
+
 /*The following definitions come from  lib/interface.c  */
 
 void load_interfaces(void);
@@ -2636,6 +2645,7 @@ void print_stat_cache_statistics(void);
 BOOL unix_convert(char *name,connection_struct *conn,char *saved_last_component, 
                   BOOL *bad_path, SMB_STRUCT_STAT *pst);
 BOOL check_name(char *name,connection_struct *conn);
+BOOL reset_stat_cache( void );
 
 /*The following definitions come from  smbd/files.c  */