Changeset 108

Timestamp:

04/29/08 14:17:48 (17 years ago)

Author:

tim

Message:

added least-recently-used cache structure.

set up SK records to use this instead of the linked list.

Location:

trunk

Files:

• include/lru_cache.h (added)
• include/regfi.h (modified) (2 diffs)
• lib/Makefile (modified) (2 diffs)
• lib/lru_cache.c (added)
• lib/regfi.c (modified) (6 diffs)

trunk/include/regfi.h

@@ -49 +49 @@
 #include "void_stack.h"
 #include "range_list.h"
+#include "lru_cache.h"
 
 /******************************************************************************/
@@ -263 +264 @@
   range_list* hbins;
   range_list* unalloc_cells;
-
-  /* file format information */
-  REGF_SK_REC* sec_desc_list;   /* list of security descriptors referenced 
-                                 * by NK records 
-                                 */
-  
+  lru_cache* sk_recs;
+
+  /* file format information */  
   uint8  magic[REGF_MAGIC_SIZE];/* "regf" */
   NTTIME mtime;

trunk/lib/Makefile

@@ -3 +3 @@
 ################################################################################
 
-FILES=regfi.o smb_deps.o void_stack.o range_list.o
+FILES=regfi.o smb_deps.o void_stack.o range_list.o lru_cache.o
 
 all: $(FILES)
@@ -19 +19 @@
         $(CC) $(CFLAGS) $(OPTS) $(INC) -c -o $@ range_list.c
 
+lru_cache.o: lru_cache.c
+        $(CC) $(CFLAGS) $(OPTS) $(INC) -c -o $@ lru_cache.c
+
 clean:
         rm -f $(FILES)

trunk/lib/regfi.c

@@ -682 +682 @@
 
 /*******************************************************************
- *******************************************************************/
-static REGF_SK_REC* find_sk_record_by_offset( REGF_FILE *file, uint32 offset )
-{
-  REGF_SK_REC *p_sk;
-  
-  for ( p_sk=file->sec_desc_list; p_sk; p_sk=p_sk->next ) {
-    if ( p_sk->sk_off == offset ) 
-      return p_sk;
-  }
-  
-  return NULL;
-}
-
-
-/*******************************************************************
- *******************************************************************/
+
 static REGF_SK_REC* find_sk_record_by_sec_desc( REGF_FILE *file, SEC_DESC *sd )
 {
@@ -707 +692 @@
   }
 
-  /* failure */
 
   return NULL;
 }
-
+ *******************************************************************/
 
 /*******************************************************************
@@ -798 +782 @@
   /* get the security descriptor.  First look if we have already parsed it */
   if((nk->sk_off!=REGF_OFFSET_NONE)
-     && !(nk->sec_desc = find_sk_record_by_offset( file, nk->sk_off )))
+     && !(nk->sec_desc = (REGF_SK_REC*)lru_cache_find(file->sk_recs, 
+                                                      &nk->sk_off, 4)))
   {
     sub_hbin = hbin;
@@ -826 +811 @@
     nk->sec_desc->sk_off = nk->sk_off;
     
-    /* add to the list of security descriptors (ref_count has been read from the files) */
-    /* XXX: this kind of caching needs to be re-evaluated */
-    DLIST_ADD( file->sec_desc_list, nk->sec_desc );
+    lru_cache_update(file->sk_recs, &nk->sk_off, 4, nk->sec_desc);
   }
   
@@ -919 +902 @@
     return NULL;
   }
+  
+  /* TODO: come up with a better secret. */
+  rb->sk_recs = lru_cache_create(127, 0xDEADBEEF, true);
 
   rla = true;
@@ -955 +941 @@
     free(range_list_get(file->unalloc_cells, i)->data);
   range_list_free(file->unalloc_cells);
+
+  lru_cache_destroy(file->sk_recs);
 
   free(file);