};
/* local constants */
-static const befs_off_t befs_bt_inval = 0xffffffffffffffffULL;
+static const befs_off_t BEFS_BT_INVAL = 0xffffffffffffffffULL;
/* local functions */
static int befs_btree_seekleaf(struct super_block *sb, const befs_data_stream *ds,
* Calls befs_read_datastream to read in the indicated btree node and
* makes sure its header fields are in cpu byteorder, byteswapping if
* necessary.
- * Note: node->bh must be NULL when this function called first
- * time. Don't forget brelse(node->bh) after last call.
+ * Note: node->bh must be NULL when this function is called the first time.
+ * Don't forget brelse(node->bh) after last call.
*
* On success, returns BEFS_OK and *@node contains the btree node that
* starts at @node_off, with the node->head fields in cpu byte order.
* Read the superblock and rootnode of the b+tree.
* Drill down through the interior nodes using befs_find_key().
* Once at the correct leaf node, use befs_find_key() again to get the
- * actuall value stored with the key.
+ * actual value stored with the key.
*/
int
befs_btree_find(struct super_block *sb, const befs_data_stream *ds,
while (!befs_leafnode(this_node)) {
res = befs_find_key(sb, this_node, key, &node_off);
- if (res == BEFS_BT_NOT_FOUND)
+ /* if no key set, try the overflow node */
+ if (res == BEFS_BT_OVERFLOW)
node_off = this_node->head.overflow;
- /* if no match, go to overflow node */
if (befs_bt_read_node(sb, ds, this_node, node_off) != BEFS_OK) {
befs_error(sb, "befs_btree_find() failed to read "
"node at %llu", node_off);
}
}
- /* at the correct leaf node now */
-
+ /* at a leaf node now, check if it is correct */
res = befs_find_key(sb, this_node, key, value);
brelse(this_node->bh);
* @findkey: Keystring to search for
* @value: If key is found, the value stored with the key is put here
*
- * finds exact match if one exists, and returns BEFS_BT_MATCH
- * If no exact match, finds first key in node that is greater
- * (alphabetically) than the search key and returns BEFS_BT_PARMATCH
- * (for partial match, I guess). Can you think of something better to
- * call it?
- *
- * If no key was a match or greater than the search key, return
- * BEFS_BT_NOT_FOUND.
+ * Finds exact match if one exists, and returns BEFS_BT_MATCH.
+ * If there is no match and node's value array is too small for key, return
+ * BEFS_BT_OVERFLOW.
+ * If no match and node should countain this key, return BEFS_BT_NOT_FOUND.
*
- * Use binary search instead of a linear.
+ * Uses binary search instead of a linear.
*/
static int
befs_find_key(struct super_block *sb, struct befs_btree_node *node,
befs_debug(sb, "---> %s %s", __func__, findkey);
- *value = 0;
-
findkey_len = strlen(findkey);
- /* if node can not contain key, just skeep this node */
+ /* if node can not contain key, just skip this node */
last = node->head.all_key_count - 1;
thiskey = befs_bt_get_key(sb, node, last, &keylen);
eq = befs_compare_strings(thiskey, keylen, findkey, findkey_len);
if (eq < 0) {
- befs_error(sb, "<--- %s %s not found", __func__, findkey);
- befs_debug(sb, "<--- %s ERROR", __func__);
- return BEFS_BT_NOT_FOUND;
+ befs_debug(sb, "<--- node can't contain %s", findkey);
+ return BEFS_BT_OVERFLOW;
}
valarray = befs_bt_valarray(node);
else
first = mid + 1;
}
+
+ /* return an existing value so caller can arrive to a leaf node */
if (eq < 0)
*value = fs64_to_cpu(sb, valarray[mid + 1]);
else
*value = fs64_to_cpu(sb, valarray[mid]);
- befs_debug(sb, "<--- %s found %s at %d", __func__, thiskey, mid);
- return BEFS_BT_PARMATCH;
+ befs_error(sb, "<--- %s %s not found", __func__, findkey);
+ befs_debug(sb, "<--- %s ERROR", __func__);
+ return BEFS_BT_NOT_FOUND;
}
/**
* @keysize: Length of the returned key
* @value: Value stored with the returned key
*
- * Heres how it works: Key_no is the index of the key/value pair to
+ * Here's how it works: Key_no is the index of the key/value pair to
* return in keybuf/value.
* Bufsize is the size of keybuf (BEFS_NAME_LEN+1 is a good size). Keysize is
* the number of characters in the key (just a convenience).
{
struct befs_btree_node *this_node;
befs_btree_super bt_super;
- befs_off_t node_off = 0;
+ befs_off_t node_off;
int cur_key;
fs64 *valarray;
char *keystart;
while (key_sum + this_node->head.all_key_count <= key_no) {
/* no more nodes to look in: key_no is too large */
- if (this_node->head.right == befs_bt_inval) {
+ if (this_node->head.right == BEFS_BT_INVAL) {
*keysize = 0;
*value = 0;
befs_debug(sb,
* @node_off: Pointer to offset of current node within datastream. Modified
* by the function.
*
- *
* Helper function for btree traverse. Moves the current position to the
* start of the first leaf node.
*
befs_leafnode(struct befs_btree_node *node)
{
/* all interior nodes (and only interior nodes) have an overflow node */
- if (node->head.overflow == befs_bt_inval)
+ if (node->head.overflow == BEFS_BT_INVAL)
return 1;
else
return 0;
*
* Returns 0 if @key1 and @key2 are equal.
* Returns >0 if @key1 is greater.
- * Returns <0 if @key2 is greater..
+ * Returns <0 if @key2 is greater.
*/
static int
befs_compare_strings(const void *key1, int keylen1,
projects / cascardo / linux.git / blobdiff