static int _search_by_key (reiserfs_filsys_t fs, struct key * key, struct path * path)
{
struct buffer_head * bh;
unsigned long block = SB_ROOT_BLOCK (fs);
struct path_element * curr;
int retval;
path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET;
while (1) {
curr = PATH_OFFSET_PELEMENT (path, ++ path->path_length);
bh = curr->pe_buffer = bread (fs->s_dev, block, fs->s_blocksize);
if (bh == 0) {
path->path_length --;
pathrelse (path);
return ITEM_NOT_FOUND;
}
retval = _bin_search (key, B_N_PKEY (bh, 0), B_NR_ITEMS (bh),
is_leaf_node (bh) ? IH_SIZE : KEY_SIZE, &(curr->pe_position), comp_keys);
if (retval == ITEM_FOUND) {
/* key found, return if this is leaf level */
if (is_leaf_node (bh)) {
path->pos_in_item = 0;
return ITEM_FOUND;
}
curr->pe_position ++;
} else {
/* key not found in the node */
if (is_leaf_node (bh))
return ITEM_NOT_FOUND;
}
block = B_N_CHILD_NUM (bh, curr->pe_position);
}
printf ("search_by_key: you can not get here\n");
return ITEM_NOT_FOUND;
}
/* NOTE: this only should be used to look for keys who exists */
int _search_by_entry_key (reiserfs_filsys_t fs, struct key * key,
struct path * path)
{
struct buffer_head * bh;
int item_pos;
struct item_head * ih;
struct key tmpkey;
if (_search_by_key (fs, key, path) == ITEM_FOUND) {
path->pos_in_item = 0;
return POSITION_FOUND;
}
bh = get_bh (path);
item_pos = get_item_pos (path);
ih = get_ih (path);
if (item_pos == 0) {
/* key is less than the smallest key in the tree */
if (not_of_one_file (&(ih->ih_key), key))
/* there are no items of that directory */
return DIRECTORY_NOT_FOUND;
if (!is_direntry_ih (ih))
reiserfs_panic ("_search_by_entry_key: found item is not of directory type %H",
ih);
/* key we looked for should be here */
path->pos_in_item = 0;
return POSITION_NOT_FOUND;
}
/* take previous item */
item_pos --;
ih --;
PATH_LAST_POSITION (path) --;
if (not_of_one_file (&(ih->ih_key), key) || !is_direntry_ih (ih)) {
/* previous item belongs to another object or is stat data, check next
item */
item_pos ++;
PATH_LAST_POSITION (path) ++;
if (item_pos < B_NR_ITEMS (bh)) {
/* next item is in the same node */
ih ++;
if (not_of_one_file (&(ih->ih_key), key)) {
/* there are no items of that directory */
path->pos_in_item = 0;
return DIRECTORY_NOT_FOUND;
}
if (!is_direntry_ih (ih))
reiserfs_panic ("_search_by_entry_key: %k is not a directory",
key);
} else {
/* next item is in right neighboring node */
struct key * next_key = _get_rkey (path);
if (next_key == 0 || not_of_one_file (next_key, key)) {
/* there are no items of that directory */
path->pos_in_item = 0;
return DIRECTORY_NOT_FOUND;
}
if (!is_direntry_key (next_key))
reiserfs_panic ("_search_by_entry_key: %k is not a directory",
key);
/* we got right delimiting key - search for it - the entry will be
pasted in position 0 */
copy_key (&tmpkey, next_key);
pathrelse (path);
if (_search_by_key (fs, &tmpkey, path) != ITEM_FOUND || PATH_LAST_POSITION (path) != 0)
reiserfs_panic ("_search_by_entry_key: item corresponding to delimiting key %k not found",
&tmpkey);
}
/* next item is the part of this directory */
path->pos_in_item = 0;
return POSITION_NOT_FOUND;
}
/* previous item is part of desired directory */
if (_bin_search (&(key->u.k_offset_v1.k_offset), B_I_DEH (bh, ih), ih_entry_count (ih),
DEH_SIZE, &(path->pos_in_item), comp_dir_entries) == ITEM_FOUND)
return POSITION_FOUND;
return POSITION_NOT_FOUND;
}
int bin_search(int *list, int n, int key) {
return _bin_search(list, key, 0, n-1);
}
