WebSVN – HelenOS – Diff – /trunk/uspace/srv/fs/fat/fat_idx.c

     link_t      freed_head;
 } unused_t;
 static LIST_INITIALIZE(unused_head);
+/**
-/** Global hash table of all used fat_idx_t structures. */
+ * Global hash table of all used fat_idx_t structures.
+ * The index structures are hashed by the dev_handle, parent node's first
+ * cluster and index within the parent directory.
+ */
-static hash_table_t used_hash;
+static hash_table_t up_hash;
+#define UPH_BUCKETS_LOG 12
+#define UPH_BUCKETS (1 << UPH_BUCKETS_LOG)
+#define UPH_DH_KEY  0
+#define UPH_PFC_KEY 1
+#define UPH_PDI_KEY 2
-#define USED_HASH_BUCKETS_LOG   12
-#define USED_HASH_BUCKETS   (1 << USED_HASH_BUCKETS_LOG)
-#define USED_HASH_DH_KEY    0
-#define USED_HASH_PFC_KEY   1
-#define USED_HASH_PDI_KEY   2
-static hash_index_t idx_hash(unsigned long key[])
+static hash_index_t pos_hash(unsigned long key[])
+{
-    dev_handle_t dev_handle = (dev_handle_t)key[USED_HASH_DH_KEY];
+    dev_handle_t dev_handle = (dev_handle_t)key[UPH_DH_KEY];
-    fat_cluster_t pfc = (fat_cluster_t)key[USED_HASH_PFC_KEY];
+    fat_cluster_t pfc = (fat_cluster_t)key[UPH_PFC_KEY];
-    unsigned pdi = (unsigned)key[USED_HASH_PDI_KEY];
+    unsigned pdi = (unsigned)key[UPH_PDI_KEY];
     hash_index_t h;
     /*
      * The least significant half of all bits are the least significant bits
      * parent directory node.
+     *
      * The most significant half of the most significant half of all bits
      * are the least significant bits of the device handle.
      */
-    h = pfc & ((USED_HASH_BUCKETS_LOG / 2) - 1);
+    h = pfc & ((1 << (UPH_BUCKETS_LOG / 2)) - 1);
-    h |= (pdi & ((USED_HASH_BUCKETS_LOG / 4) - 1)) <<
+    h |= (pdi & ((1 << (UPH_BUCKETS_LOG / 4)) - 1)) <<
-        (USED_HASH_BUCKETS_LOG / 2);
+        (UPH_BUCKETS_LOG / 2);
-    h |= (dev_handle & ((USED_HASH_BUCKETS_LOG / 4) - 1)) <<
+    h |= (dev_handle & ((1 << (UPH_BUCKETS_LOG / 4)) - 1)) <<
-        (3 * (USED_HASH_BUCKETS_LOG / 4));
+        (3 * (UPH_BUCKETS_LOG / 4));
     return h;
+}
-static int idx_compare(unsigned long key[], hash_count_t keys, link_t *item)
+static int pos_compare(unsigned long key[], hash_count_t keys, link_t *item)
+{
-    dev_handle_t dev_handle = (dev_handle_t)key[USED_HASH_DH_KEY];
+    dev_handle_t dev_handle = (dev_handle_t)key[UPH_DH_KEY];
-    fat_cluster_t pfc = (fat_cluster_t)key[USED_HASH_PFC_KEY];
+    fat_cluster_t pfc = (fat_cluster_t)key[UPH_PFC_KEY];
-    unsigned pdi = (unsigned)key[USED_HASH_PDI_KEY];
+    unsigned pdi = (unsigned)key[UPH_PDI_KEY];
-    fat_idx_t *fidx = list_get_instance(item, fat_idx_t, uh_link);
+    fat_idx_t *fidx = list_get_instance(item, fat_idx_t, uph_link);
     return (dev_handle == fidx->dev_handle) && (pfc == fidx->pfc) &&
         (pdi == fidx->pdi);
+}
+static void pos_remove_callback(link_t *item)
+{
+    /* nothing to do */
+}
+static hash_table_operations_t uph_ops = {
+    .hash = pos_hash,
+    .compare = pos_compare,
+    .remove_callback = pos_remove_callback,
+};
+/**
+ * Global hash table of all used fat_idx_t structures.
+ * The index structures are hashed by the dev_handle and index.
+ */
+static hash_table_t ui_hash;
+#define UIH_BUCKETS_LOG 12
+#define UIH_BUCKETS (1 << UIH_BUCKETS_LOG)
+#define UIH_DH_KEY  0
+#define UIH_INDEX_KEY   1
+static hash_index_t idx_hash(unsigned long key[])
+{
+    dev_handle_t dev_handle = (dev_handle_t)key[UIH_DH_KEY];
+    fs_index_t index = (fs_index_t)key[UIH_INDEX_KEY];
+    hash_index_t h;
+    h = dev_handle & ((1 << (UIH_BUCKETS_LOG / 2)) - 1);
+    h |= (index & ((1 << (UIH_BUCKETS_LOG / 2)) - 1)) <<
+        (UIH_BUCKETS_LOG / 2);
+    return h;
+}
+static int idx_compare(unsigned long key[], hash_count_t keys, link_t *item)
+{
+    dev_handle_t dev_handle = (dev_handle_t)key[UIH_DH_KEY];
+    fs_index_t index = (fs_index_t)key[UIH_INDEX_KEY];
+    fat_idx_t *fidx = list_get_instance(item, fat_idx_t, uih_link);
+    return (dev_handle == fidx->dev_handle) && (index == fidx->index);
+}
 static void idx_remove_callback(link_t *item)
+{
     /* nothing to do */
+}
-static hash_table_operations_t used_idx_ops = {
+static hash_table_operations_t uih_ops = {
     .hash = idx_hash,
     .compare = idx_compare,
     .remove_callback = idx_remove_callback,
 };
         n->last = index;
         list_append(&n->link, &u->freed_head);
+    }
+}
+fat_idx_t *
-fat_idx_t *fat_idx_map(dev_handle_t dev_handle, fat_cluster_t pfc, unsigned pdi)
+fat_idx_get_by_pos(dev_handle_t dev_handle, fat_cluster_t pfc, unsigned pdi)
+{
     fat_idx_t *fidx;
     link_t *l;
-    unsigned long key[] = {
+    unsigned long pkey[] = {
-        [USED_HASH_DH_KEY] = dev_handle,
+        [UPH_DH_KEY] = dev_handle,
-        [USED_HASH_PFC_KEY] = pfc,
+        [UPH_PFC_KEY] = pfc,
-        [USED_HASH_PDI_KEY] = pdi,
+        [UPH_PDI_KEY] = pdi,
     };
-    l = hash_table_find(&used_hash, key);
+    l = hash_table_find(&up_hash, pkey);
     if (l) {
-        fidx = hash_table_get_instance(l, fat_idx_t, uh_link);
+        fidx = hash_table_get_instance(l, fat_idx_t, uph_link);
     } else {
         fidx = (fat_idx_t *) malloc(sizeof(fat_idx_t));
         if (!fidx) {
             return NULL;
+        }
         if (!fat_idx_alloc(dev_handle, &fidx->index)) {
             free(fidx);
             return NULL;
+        }
+        unsigned long ikey[] = {
+            [UIH_DH_KEY] = dev_handle,
+            [UIH_INDEX_KEY] = fidx->index,
+        };
+        link_initialize(&fidx->uph_link);
-        link_initialize(&fidx->uh_link);
+        link_initialize(&fidx->uih_link);
         fidx->dev_handle = dev_handle;
         fidx->pfc = pfc;
         fidx->pdi = pdi;
         fidx->nodep = NULL;
-        hash_table_insert(&used_hash, key, &fidx->uh_link);
+        hash_table_insert(&up_hash, pkey, &fidx->uph_link);
+        hash_table_insert(&ui_hash, ikey, &fidx->uih_link);
+    }
+    return fidx;
+}
+fat_idx_t *
+fat_idx_get_by_index(dev_handle_t dev_handle, fs_index_t index)
+{
+    fat_idx_t *fidx = NULL;
+    link_t *l;
+    unsigned long ikey[] = {
+        [UIH_DH_KEY] = dev_handle,
+        [UIH_INDEX_KEY] = index,
+    };
+    l = hash_table_find(&ui_hash, ikey);
+    if (l) {
+        fidx = hash_table_get_instance(l, fat_idx_t, uih_link);
+    }
     return fidx;
+}

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/fat/fat_idx.c – Rev 2889 → 2890