File created.

src/server/cache-node.c

+/*
+ * cache-node.c
+ *
+ * Used in diskomd.
+ */
+
+EXPORT const Cache_node EMPTY_CACHE_NODE =
+    ((Cache_node){{ 0, 0, 0}, NULL, NULL, 0, 0, 0, 0, NULL, NULL, 0});
+
+EXPORT const Cache_node_block EMPTY_CACHE_NODE_BLOCK =
+    ((Cache_node_block){ 0, NULL, NULL});
+
+EXPORT const Cache_node_mcb EMPTY_CACHE_NODE_MCB =
+    ((Cache_node_mcb){ 0, NULL, 0, 0, NULL, NULL, 0, NULL });
+
+
+EXPORT  void
+unlink_lru(Cache_node *node,
+	   Cache_node **lru,
+	   Cache_node **mru)
+{
+    Cache_node *link;
+    
+    link = node->lru;
+
+    if ( node->lru != NULL )
+	node->lru->mru = node->mru;
+    else if (*lru == node)
+	*lru = node->mru;
+
+    if ( node->mru != NULL )
+	node->mru->lru = link;
+    else if (*mru == node)
+	*mru = link;
+}
+
+EXPORT  void
+insert_mru(Cache_node *node,
+	   Cache_node **lru,
+	   Cache_node **mru)
+{
+    node->mru = NULL;
+    node->lru = *mru;
+    *mru = node;
+    if ( *lru == NULL )
+	*lru = node;
+
+    if ( node->lru != NULL )
+	node->lru->mru = node;
+}
+
+
+EXPORT Cache_node_mcb *
+create_cache_node_mcb(int mcb_size, 
+		      int table_size)
+{
+    Cache_node_mcb *tmp;
+
+    tmp = alloc_cache_node_mcb();
+    *tmp = EMPTY_CACHE_NODE_MCB;
+    tmp->lookup_table = smalloc(sizeof(Cache_node *) * table_size);
+    tmp->lookup_table_size = table_size;
+    tmp->mcb_size = mcb_size;
+    tmp->last_block = alloc_cache_node_block();
+
+    return tmp;
+}
+
+/* +++ No check is done that it is initialized. */
+EXPORT Cache_node *
+get_cache_node (Cache_node_mcb *control,
+		u_long          key)
+{
+    if ( key >= control->lookup_table_size )
+	return NULL;
+
+    return control->lookup_table[ key ];
+}
+
+static Cache_node *
+alloc_cache_node(void)
+{
+    Cache_node *c;
+
+    c = smalloc(sizeof(Cache_node));
+    *c = EMPTY_CACHE_NODE;
+    return c;
+}
+
+EXPORT  void
+create_cache_node (Cache_node_mcb *control,
+		   u_long          key)
+{
+    if ( key >= control->lookup_table_size )
+	restart_kom("ERROR: set_cache_node(%lu, %lu, value): "
+		    "lookup_table_size = %lu\n",
+		    control->lookup_table_size);
+
+    control->lookup_table[ key ] = alloc_cache_node();
+}
+
+
+EXPORT void
+set_mru(Cache_node_mcb *mcb,
+	u_long         key)
+{
+    Cache_node *node;
+
+    node = get_cache_node(mcb, key);
+
+    if (node == NULL)
+	restart_kom("set_mru(%d): nonexistent.\n", key);
+
+    unlink_lru(node, &mcb->lru, &mcb->mru);
+    insert_mru(node, &mcb->lru, &mcb->mru);
+}
+

src/server/cache-node.h

+/*
+ * cache-node.h
+ */
+
+typedef struct cache_node {
+    struct {
+	u_int	exists : 1;
+	u_int	exists_b : 1;
+	u_int	dirty : 1;		/* [r *ptr modifierad? */
+    } s;
+    void   *snap_shot;		/* Dirty data to be written to file B. */
+				/* (Dirty relative to file A). */
+    void   *ptr;		/* In-core data. */
+    long   pos;			/* Position to element in file A. */
+    long   size;		/* Size on disk. */
+    long   pos_b;		/* Position to element in file B. */
+    long   size_b;		/* Size in file B. */
+    struct cache_node *lru;
+    struct cache_node *mru;
+    int	lock_cnt;
+} Cache_node;
+
+extern const Cache_node EMPTY_CACHE_NODE;
+
+
+typedef struct cache_node_block {
+    int next_free;
+    Cache_node *nodes;		/* Pointer to an array with
+				   mcb_size elements. */
+    struct cache_node_block *link; /* Points to previous block. */
+} Cache_node_block;
+
+extern const Cache_node_block EMPTY_CACHE_NODE_BLOCK;
+	  
+
+typedef struct cache_node_mcb {
+    int mcb_size;		/* Number of cache_nodes in each block. */
+    Cache_node_block *last_block; /* The block where new cache_nodes
+				   * can be allocated. */
+    u_long hits;
+    u_long misses;
+    Cache_node	*mru;
+    Cache_node	*lru;
+    u_long lookup_table_size;
+    Cache_node	*lookup_table;	/* Easy to implement, but memory expensive. */
+} Cache_node_mcb;
+
+
+extern const Cache_node_mcb EMPTY_CACHE_NODE_MCB;
+
+extern  void
+unlink_lru(Cache_node *node,
+	   Cache_node **lru,
+	   Cache_node **mru);
+
+extern  void
+insert_mru(Cache_node *node,
+	   Cache_node **lru,
+	   Cache_node **mru);
+
+
+extern Cache_node_mcb *
+create_cache_node_mcb(int mcb_size, 
+		      int table_size);
+
+
+extern Cache_node *
+get_cache_node (Cache_node_mcb *control,
+		u_long          key);
+
+
+extern  void
+create_cache_node (Cache_node_mcb *control,
+		   u_long          key);
+
+
+extern void
+set_mru(Cache_node_mcb *mcb,
+	u_long         key);
+
+