#include #include #include "kerncompat.h" #include "radix-tree.h" #include "ctree.h" #include "disk-io.h" static inline void init_path(struct ctree_path *p) { memset(p, 0, sizeof(*p)); } static void release_path(struct ctree_root *root, struct ctree_path *p) { int i; for (i = 0; i < MAX_LEVEL; i++) { if (!p->nodes[i]) break; tree_block_release(root, p->nodes[i]); } } static inline unsigned int leaf_data_end(struct leaf *leaf) { unsigned int nr = leaf->header.nritems; if (nr == 0) return ARRAY_SIZE(leaf->data); return leaf->items[nr-1].offset; } static inline int leaf_free_space(struct leaf *leaf) { int data_end = leaf_data_end(leaf); int nritems = leaf->header.nritems; char *items_end = (char *)(leaf->items + nritems + 1); return (char *)(leaf->data + data_end) - (char *)items_end; } int comp_keys(struct key *k1, struct key *k2) { if (k1->objectid > k2->objectid) return 1; if (k1->objectid < k2->objectid) return -1; if (k1->flags > k2->flags) return 1; if (k1->flags < k2->flags) return -1; if (k1->offset > k2->offset) return 1; if (k1->offset < k2->offset) return -1; return 0; } int generic_bin_search(char *p, int item_size, struct key *key, int max, int *slot) { int low = 0; int high = max; int mid; int ret; struct key *tmp; while(low < high) { mid = (low + high) / 2; tmp = (struct key *)(p + mid * item_size); ret = comp_keys(tmp, key); if (ret < 0) low = mid + 1; else if (ret > 0) high = mid; else { *slot = mid; return 0; } } *slot = low; return 1; } int bin_search(struct node *c, struct key *key, int *slot) { if (is_leaf(c->header.flags)) { struct leaf *l = (struct leaf *)c; return generic_bin_search((void *)l->items, sizeof(struct item), key, c->header.nritems, slot); } else { return generic_bin_search((void *)c->keys, sizeof(struct key), key, c->header.nritems, slot); } return -1; } int search_slot(struct ctree_root *root, struct key *key, struct ctree_path *p) { struct tree_buffer *b = root->node; struct node *c; int slot; int ret; int level; b->count++; while (b) { c = &b->node; level = node_level(c->header.flags); p->nodes[level] = b; ret = bin_search(c, key, &slot); if (!is_leaf(c->header.flags)) { if (ret && slot > 0) slot -= 1; p->slots[level] = slot; b = read_tree_block(root, c->blockptrs[slot]); continue; } else { p->slots[level] = slot; return ret; } } return -1; } static void fixup_low_keys(struct ctree_root *root, struct ctree_path *path, struct key *key, int level) { int i; /* adjust the pointers going up the tree */ for (i = level; i < MAX_LEVEL; i++) { struct node *t; int tslot = path->slots[i]; if (!path->nodes[i]) break; t = &path->nodes[i]->node; memcpy(t->keys + tslot, key, sizeof(*key)); write_tree_block(root, path->nodes[i]); if (tslot != 0) break; } } int __insert_ptr(struct ctree_root *root, struct ctree_path *path, struct key *key, u64 blocknr, int slot, int level) { struct node *c; struct node *lower; struct key *lower_key; int nritems; /* need a new root */ if (!path->nodes[level]) { struct tree_buffer *t; t = alloc_free_block(root); c = &t->node; memset(c, 0, sizeof(c)); c->header.nritems = 2; c->header.flags = node_level(level); c->header.blocknr = t->blocknr; lower = &path->nodes[level-1]->node; if (is_leaf(lower->header.flags)) lower_key = &((struct leaf *)lower)->items[0].key; else lower_key = lower->keys; memcpy(c->keys, lower_key, sizeof(struct key)); memcpy(c->keys + 1, key, sizeof(struct key)); c->blockptrs[0] = path->nodes[level-1]->blocknr; c->blockptrs[1] = blocknr; /* the path has an extra ref to root->node */ tree_block_release(root, root->node); root->node = t; t->count++; write_tree_block(root, t); path->nodes[level] = t; path->slots[level] = 0; if (c->keys[1].objectid == 0) BUG(); return 0; } lower = &path->nodes[level]->node; nritems = lower->header.nritems; if (slot > nritems) BUG(); if (nritems == NODEPTRS_PER_BLOCK) BUG(); if (slot != nritems) { memmove(lower->keys + slot + 1, lower->keys + slot, (nritems - slot) * sizeof(struct key)); memmove(lower->blockptrs + slot + 1, lower->blockptrs + slot, (nritems - slot) * sizeof(u64)); } memcpy(lower->keys + slot, key, sizeof(struct key)); lower->blockptrs[slot] = blocknr; lower->header.nritems++; if (lower->keys[1].objectid == 0) BUG(); write_tree_block(root, path->nodes[level]); return 0; } int push_node_left(struct ctree_root *root, struct ctree_path *path, int level) { int slot; struct node *left; struct node *right; int push_items = 0; int left_nritems; int right_nritems; struct tree_buffer *t; struct tree_buffer *right_buf; if (level == MAX_LEVEL - 1 || path->nodes[level + 1] == 0) return 1; slot = path->slots[level + 1]; if (slot == 0) return 1; t = read_tree_block(root, path->nodes[level + 1]->node.blockptrs[slot - 1]); left = &t->node; right_buf = path->nodes[level]; right = &right_buf->node; left_nritems = left->header.nritems; right_nritems = right->header.nritems; push_items = NODEPTRS_PER_BLOCK - (left_nritems + 1); if (push_items <= 0) { tree_block_release(root, t); return 1; } if (right_nritems < push_items) push_items = right_nritems; memcpy(left->keys + left_nritems, right->keys, push_items * sizeof(struct key)); memcpy(left->blockptrs + left_nritems, right->blockptrs, push_items * sizeof(u64)); memmove(right->keys, right->keys + push_items, (right_nritems - push_items) * sizeof(struct key)); memmove(right->blockptrs, right->blockptrs + push_items, (right_nritems - push_items) * sizeof(u64)); right->header.nritems -= push_items; left->header.nritems += push_items; /* adjust the pointers going up the tree */ fixup_low_keys(root, path, right->keys, level + 1); write_tree_block(root, t); write_tree_block(root, right_buf); /* then fixup the leaf pointer in the path */ if (path->slots[level] < push_items) { path->slots[level] += left_nritems; tree_block_release(root, path->nodes[level]); path->nodes[level] = t; path->slots[level + 1] -= 1; } else { path->slots[level] -= push_items; tree_block_release(root, t); } return 0; } int push_node_right(struct ctree_root *root, struct ctree_path *path, int level) { int slot; struct tree_buffer *t; struct tree_buffer *src_buffer; struct node *dst; struct node *src; int push_items = 0; int dst_nritems; int src_nritems; if (level == MAX_LEVEL - 1 || path->nodes[level + 1] == 0) return 1; slot = path->slots[level + 1]; if (slot == NODEPTRS_PER_BLOCK - 1) return 1; if (slot >= path->nodes[level + 1]->node.header.nritems -1) return 1; t = read_tree_block(root, path->nodes[level + 1]->node.blockptrs[slot + 1]); dst = &t->node; src_buffer = path->nodes[level]; src = &src_buffer->node; dst_nritems = dst->header.nritems; src_nritems = src->header.nritems; push_items = NODEPTRS_PER_BLOCK - (dst_nritems + 1); if (push_items <= 0) { tree_block_release(root, t); return 1; } if (src_nritems < push_items) push_items = src_nritems; memmove(dst->keys + push_items, dst->keys, dst_nritems * sizeof(struct key)); memcpy(dst->keys, src->keys + src_nritems - push_items, push_items * sizeof(struct key)); memmove(dst->blockptrs + push_items, dst->blockptrs, dst_nritems * sizeof(u64)); memcpy(dst->blockptrs, src->blockptrs + src_nritems - push_items, push_items * sizeof(u64)); src->header.nritems -= push_items; dst->header.nritems += push_items; /* adjust the pointers going up the tree */ memcpy(path->nodes[level + 1]->node.keys + path->slots[level + 1] + 1, dst->keys, sizeof(struct key)); write_tree_block(root, path->nodes[level + 1]); write_tree_block(root, t); write_tree_block(root, src_buffer); /* then fixup the leaf pointer in the path */ if (path->slots[level] >= src->header.nritems) { path->slots[level] -= src->header.nritems; tree_block_release(root, path->nodes[level]); path->nodes[level] = t; path->slots[level + 1] += 1; } else { tree_block_release(root, t); } return 0; } int insert_ptr(struct ctree_root *root, struct ctree_path *path, struct key *key, u64 blocknr, int level) { struct tree_buffer *t = path->nodes[level]; struct node *c = &path->nodes[level]->node; struct node *b; struct tree_buffer *b_buffer; struct tree_buffer *bal[MAX_LEVEL]; int bal_level = level; int mid; int bal_start = -1; memset(bal, 0, ARRAY_SIZE(bal)); while(t && t->node.header.nritems == NODEPTRS_PER_BLOCK) { c = &t->node; if (push_node_left(root, path, node_level(c->header.flags)) == 0) break; if (push_node_right(root, path, node_level(c->header.flags)) == 0) break; bal_start = bal_level; if (bal_level == MAX_LEVEL - 1) BUG(); b_buffer = alloc_free_block(root); b = &b_buffer->node; b->header.flags = c->header.flags; b->header.blocknr = b_buffer->blocknr; mid = (c->header.nritems + 1) / 2; memcpy(b->keys, c->keys + mid, (c->header.nritems - mid) * sizeof(struct key)); memcpy(b->blockptrs, c->blockptrs + mid, (c->header.nritems - mid) * sizeof(u64)); b->header.nritems = c->header.nritems - mid; c->header.nritems = mid; write_tree_block(root, t); write_tree_block(root, b_buffer); bal[bal_level] = b_buffer; if (bal_level == MAX_LEVEL - 1) break; bal_level += 1; t = path->nodes[bal_level]; } while(bal_start > 0) { b_buffer = bal[bal_start]; c = &path->nodes[bal_start]->node; __insert_ptr(root, path, b_buffer->node.keys, b_buffer->blocknr, path->slots[bal_start + 1] + 1, bal_start + 1); if (path->slots[bal_start] >= c->header.nritems) { path->slots[bal_start] -= c->header.nritems; tree_block_release(root, path->nodes[bal_start]); path->nodes[bal_start] = b_buffer; path->slots[bal_start + 1] += 1; } else { tree_block_release(root, b_buffer); } bal_start--; if (!bal[bal_start]) break; } return __insert_ptr(root, path, key, blocknr, path->slots[level] + 1, level); } int leaf_space_used(struct leaf *l, int start, int nr) { int data_len; int end = start + nr - 1; if (!nr) return 0; data_len = l->items[start].offset + l->items[start].size; data_len = data_len - l->items[end].offset; data_len += sizeof(struct item) * nr; return data_len; } int push_leaf_left(struct ctree_root *root, struct ctree_path *path, int data_size) { struct tree_buffer *right_buf = path->nodes[0]; struct leaf *right = &right_buf->leaf; struct tree_buffer *t; struct leaf *left; int slot; int i; int free_space; int push_space = 0; int push_items = 0; struct item *item; int old_left_nritems; slot = path->slots[1]; if (slot == 0) { return 1; } if (!path->nodes[1]) { return 1; } t = read_tree_block(root, path->nodes[1]->node.blockptrs[slot - 1]); left = &t->leaf; free_space = leaf_free_space(left); if (free_space < data_size + sizeof(struct item)) { tree_block_release(root, t); return 1; } for (i = 0; i < right->header.nritems; i++) { item = right->items + i; if (path->slots[0] == i) push_space += data_size + sizeof(*item); if (item->size + sizeof(*item) + push_space > free_space) break; push_items++; push_space += item->size + sizeof(*item); } if (push_items == 0) { tree_block_release(root, t); return 1; } /* push data from right to left */ memcpy(left->items + left->header.nritems, right->items, push_items * sizeof(struct item)); push_space = LEAF_DATA_SIZE - right->items[push_items -1].offset; memcpy(left->data + leaf_data_end(left) - push_space, right->data + right->items[push_items - 1].offset, push_space); old_left_nritems = left->header.nritems; BUG_ON(old_left_nritems < 0); for(i = old_left_nritems; i < old_left_nritems + push_items; i++) { left->items[i].offset -= LEAF_DATA_SIZE - left->items[old_left_nritems -1].offset; } left->header.nritems += push_items; /* fixup right node */ push_space = right->items[push_items-1].offset - leaf_data_end(right); memmove(right->data + LEAF_DATA_SIZE - push_space, right->data + leaf_data_end(right), push_space); memmove(right->items, right->items + push_items, (right->header.nritems - push_items) * sizeof(struct item)); right->header.nritems -= push_items; push_space = LEAF_DATA_SIZE; for (i = 0; i < right->header.nritems; i++) { right->items[i].offset = push_space - right->items[i].size; push_space = right->items[i].offset; } write_tree_block(root, t); write_tree_block(root, right_buf); fixup_low_keys(root, path, &right->items[0].key, 1); /* then fixup the leaf pointer in the path */ if (path->slots[0] < push_items) { path->slots[0] += old_left_nritems; tree_block_release(root, path->nodes[0]); path->nodes[0] = t; path->slots[1] -= 1; } else { tree_block_release(root, t); path->slots[0] -= push_items; } BUG_ON(path->slots[0] < 0); return 0; } int split_leaf(struct ctree_root *root, struct ctree_path *path, int data_size) { struct tree_buffer *l_buf = path->nodes[0]; struct leaf *l = &l_buf->leaf; int nritems; int mid; int slot; struct leaf *right; struct tree_buffer *right_buffer; int space_needed = data_size + sizeof(struct item); int data_copy_size; int rt_data_off; int i; int ret; if (push_leaf_left(root, path, data_size) == 0) { l_buf = path->nodes[0]; l = &l_buf->leaf; if (leaf_free_space(l) >= sizeof(struct item) + data_size) return 0; } slot = path->slots[0]; nritems = l->header.nritems; mid = (nritems + 1)/ 2; right_buffer = alloc_free_block(root); BUG_ON(!right_buffer); BUG_ON(mid == nritems); right = &right_buffer->leaf; memset(right, 0, sizeof(*right)); if (mid <= slot) { if (leaf_space_used(l, mid, nritems - mid) + space_needed > LEAF_DATA_SIZE) BUG(); } else { if (leaf_space_used(l, 0, mid + 1) + space_needed > LEAF_DATA_SIZE) BUG(); } right->header.nritems = nritems - mid; right->header.blocknr = right_buffer->blocknr; right->header.flags = node_level(0); data_copy_size = l->items[mid].offset + l->items[mid].size - leaf_data_end(l); memcpy(right->items, l->items + mid, (nritems - mid) * sizeof(struct item)); memcpy(right->data + LEAF_DATA_SIZE - data_copy_size, l->data + leaf_data_end(l), data_copy_size); rt_data_off = LEAF_DATA_SIZE - (l->items[mid].offset + l->items[mid].size); for (i = 0; i < right->header.nritems; i++) { right->items[i].offset += rt_data_off; } l->header.nritems = mid; ret = insert_ptr(root, path, &right->items[0].key, right_buffer->blocknr, 1); write_tree_block(root, right_buffer); write_tree_block(root, l_buf); BUG_ON(path->slots[0] != slot); if (mid <= slot) { tree_block_release(root, path->nodes[0]); path->nodes[0] = right_buffer; path->slots[0] -= mid; path->slots[1] += 1; } else tree_block_release(root, right_buffer); BUG_ON(path->slots[0] < 0); return ret; } int insert_item(struct ctree_root *root, struct key *key, void *data, int data_size) { int ret; int slot; int slot_orig; struct leaf *leaf; struct tree_buffer *leaf_buf; unsigned int nritems; unsigned int data_end; struct ctree_path path; if (!root->node) { struct tree_buffer *t; t = alloc_free_block(root); BUG_ON(!t); t->node.header.nritems = 0; t->node.header.flags = node_level(0); t->node.header.blocknr = t->blocknr; root->node = t; write_tree_block(root, t); } init_path(&path); ret = search_slot(root, key, &path); if (ret == 0) { release_path(root, &path); return -EEXIST; } slot_orig = path.slots[0]; leaf_buf = path.nodes[0]; leaf = &leaf_buf->leaf; if (leaf_free_space(leaf) < sizeof(struct item) + data_size) { split_leaf(root, &path, data_size); leaf_buf = path.nodes[0]; leaf = &path.nodes[0]->leaf; } nritems = leaf->header.nritems; data_end = leaf_data_end(leaf); if (leaf_free_space(leaf) < sizeof(struct item) + data_size) BUG(); slot = path.slots[0]; BUG_ON(slot < 0); if (slot == 0) fixup_low_keys(root, &path, key, 1); if (slot != nritems) { int i; unsigned int old_data = leaf->items[slot].offset + leaf->items[slot].size; /* * item0..itemN ... dataN.offset..dataN.size .. data0.size */ /* first correct the data pointers */ for (i = slot; i < nritems; i++) leaf->items[i].offset -= data_size; /* shift the items */ memmove(leaf->items + slot + 1, leaf->items + slot, (nritems - slot) * sizeof(struct item)); /* shift the data */ memmove(leaf->data + data_end - data_size, leaf->data + data_end, old_data - data_end); data_end = old_data; } memcpy(&leaf->items[slot].key, key, sizeof(struct key)); leaf->items[slot].offset = data_end - data_size; leaf->items[slot].size = data_size; memcpy(leaf->data + data_end - data_size, data, data_size); leaf->header.nritems += 1; write_tree_block(root, leaf_buf); if (leaf_free_space(leaf) < 0) BUG(); release_path(root, &path); return 0; } int del_ptr(struct ctree_root *root, struct ctree_path *path, int level) { int slot; struct tree_buffer *t; struct node *node; int nritems; while(1) { t = path->nodes[level]; if (!t) break; node = &t->node; slot = path->slots[level]; nritems = node->header.nritems; if (slot != nritems -1) { memmove(node->keys + slot, node->keys + slot + 1, sizeof(struct key) * (nritems - slot - 1)); memmove(node->blockptrs + slot, node->blockptrs + slot + 1, sizeof(u64) * (nritems - slot - 1)); } node->header.nritems--; write_tree_block(root, t); if (node->header.nritems != 0) { int tslot; if (slot == 0) fixup_low_keys(root, path, node->keys, level + 1); tslot = path->slots[level+1]; t->count++; push_node_left(root, path, level); if (node->header.nritems) { push_node_right(root, path, level); } if (node->header.nritems) { tree_block_release(root, t); break; } tree_block_release(root, t); path->slots[level+1] = tslot; } if (t == root->node) { /* just turn the root into a leaf and break */ root->node->node.header.flags = node_level(0); write_tree_block(root, t); break; } level++; if (!path->nodes[level]) BUG(); } return 0; } int del_item(struct ctree_root *root, struct ctree_path *path) { int slot; struct leaf *leaf; struct tree_buffer *leaf_buf; int doff; int dsize; leaf_buf = path->nodes[0]; leaf = &leaf_buf->leaf; slot = path->slots[0]; doff = leaf->items[slot].offset; dsize = leaf->items[slot].size; if (slot != leaf->header.nritems - 1) { int i; int data_end = leaf_data_end(leaf); memmove(leaf->data + data_end + dsize, leaf->data + data_end, doff - data_end); for (i = slot + 1; i < leaf->header.nritems; i++) leaf->items[i].offset += dsize; memmove(leaf->items + slot, leaf->items + slot + 1, sizeof(struct item) * (leaf->header.nritems - slot - 1)); } leaf->header.nritems -= 1; if (leaf->header.nritems == 0) { if (leaf_buf == root->node) { leaf->header.flags = node_level(0); write_tree_block(root, leaf_buf); } else del_ptr(root, path, 1); } else { if (slot == 0) fixup_low_keys(root, path, &leaf->items[0].key, 1); write_tree_block(root, leaf_buf); if (leaf_space_used(leaf, 0, leaf->header.nritems) < LEAF_DATA_SIZE / 4) { /* push_leaf_left fixes the path. * make sure the path still points to our leaf * for possible call to del_ptr below */ slot = path->slots[1]; leaf_buf->count++; push_leaf_left(root, path, 1); if (leaf->header.nritems == 0) { path->slots[1] = slot; del_ptr(root, path, 1); } tree_block_release(root, leaf_buf); } } return 0; } void print_leaf(struct leaf *l) { int i; int nr = l->header.nritems; struct item *item; printf("leaf %lu total ptrs %d free space %d\n", l->header.blocknr, nr, leaf_free_space(l)); fflush(stdout); for (i = 0 ; i < nr ; i++) { item = l->items + i; printf("\titem %d key (%lu %u %lu) itemoff %d itemsize %d\n", i, item->key.objectid, item->key.flags, item->key.offset, item->offset, item->size); fflush(stdout); printf("\t\titem data %.*s\n", item->size, l->data+item->offset); fflush(stdout); } } void print_tree(struct ctree_root *root, struct tree_buffer *t) { int i; int nr; struct node *c; if (!t) return; c = &t->node; nr = c->header.nritems; if (c->header.blocknr != t->blocknr) BUG(); if (is_leaf(c->header.flags)) { print_leaf((struct leaf *)c); return; } printf("node %lu level %d total ptrs %d free spc %lu\n", t->blocknr, node_level(c->header.flags), c->header.nritems, NODEPTRS_PER_BLOCK - c->header.nritems); fflush(stdout); for (i = 0; i < nr; i++) { printf("\tkey %d (%lu %u %lu) block %lu\n", i, c->keys[i].objectid, c->keys[i].flags, c->keys[i].offset, c->blockptrs[i]); fflush(stdout); } for (i = 0; i < nr; i++) { struct tree_buffer *next_buf = read_tree_block(root, c->blockptrs[i]); struct node *next = &next_buf->node; if (is_leaf(next->header.flags) && node_level(c->header.flags) != 1) BUG(); if (node_level(next->header.flags) != node_level(c->header.flags) - 1) BUG(); print_tree(root, next_buf); tree_block_release(root, next_buf); } } /* for testing only */ int next_key(int i, int max_key) { return rand() % max_key; // return i; } int main() { struct ctree_root *root; struct key ins; struct key last = { (u64)-1, 0, 0}; char *buf; int i; int num; int ret; int run_size = 1000000; int max_key = 100000000; int tree_size = 0; struct ctree_path path; radix_tree_init(); root = open_ctree("dbfile"); srand(55); for (i = 0; i < run_size; i++) { buf = malloc(64); num = next_key(i, max_key); // num = i; sprintf(buf, "string-%d", num); // printf("insert %d\n", num); ins.objectid = num; ins.offset = 0; ins.flags = 0; ret = insert_item(root, &ins, buf, strlen(buf)); if (!ret) tree_size++; } close_ctree(root); root = open_ctree("dbfile"); printf("starting search\n"); srand(55); for (i = 0; i < run_size; i++) { num = next_key(i, max_key); ins.objectid = num; init_path(&path); ret = search_slot(root, &ins, &path); if (ret) { print_tree(root, root->node); printf("unable to find %d\n", num); exit(1); } release_path(root, &path); } close_ctree(root); root = open_ctree("dbfile"); printf("node %p level %d total ptrs %d free spc %lu\n", root->node, node_level(root->node->node.header.flags), root->node->node.header.nritems, NODEPTRS_PER_BLOCK - root->node->node.header.nritems); printf("all searches good, deleting some items\n"); i = 0; srand(55); for (i = 0 ; i < run_size/4; i++) { num = next_key(i, max_key); ins.objectid = num; init_path(&path); ret = search_slot(root, &ins, &path); if (ret) continue; ret = del_item(root, &path); if (ret != 0) BUG(); release_path(root, &path); tree_size--; } srand(128); for (i = 0; i < run_size; i++) { buf = malloc(64); num = next_key(i, max_key); sprintf(buf, "string-%d", num); ins.objectid = num; ret = insert_item(root, &ins, buf, strlen(buf)); if (!ret) tree_size++; } close_ctree(root); root = open_ctree("dbfile"); printf("starting search2\n"); srand(128); for (i = 0; i < run_size; i++) { num = next_key(i, max_key); ins.objectid = num; init_path(&path); ret = search_slot(root, &ins, &path); if (ret) { print_tree(root, root->node); printf("unable to find %d\n", num); exit(1); } release_path(root, &path); } printf("starting big long delete run\n"); while(root->node && root->node->node.header.nritems > 0) { struct leaf *leaf; int slot; ins.objectid = (u64)-1; init_path(&path); ret = search_slot(root, &ins, &path); if (ret == 0) BUG(); leaf = &path.nodes[0]->leaf; slot = path.slots[0]; if (slot != leaf->header.nritems) BUG(); while(path.slots[0] > 0) { path.slots[0] -= 1; slot = path.slots[0]; leaf = &path.nodes[0]->leaf; if (comp_keys(&last, &leaf->items[slot].key) <= 0) BUG(); memcpy(&last, &leaf->items[slot].key, sizeof(last)); ret = del_item(root, &path); if (ret != 0) { printf("del_item returned %d\n", ret); BUG(); } tree_size--; } release_path(root, &path); } close_ctree(root); printf("tree size is now %d\n", tree_size); return 0; }