int initialize_db (const char * filename) {
const char sql[] = "SELECT * FROM movies";
sqlite3 * pDb = NULL;
int nresult, ret = 0;
ptreeroot = alloc_tnode();
if ( (nresult = sqlite3_open(filename,&pDb)) != SQLITE_OK) {
fprintf(stderr,"Error: the database could not be opened. %s (%d)\n", sqlite3_errmsg(pDb), nresult);
ret = 1;
} else {
char * errmsg = NULL;
nresult = sqlite3_exec(pDb, sql, store_result, NULL, &errmsg);
if (errmsg) {
fprintf(stderr, "Error executing SQL query: %s.\n", errmsg);
sqlite3_free(errmsg);
ret = 2;
}
}
sqlite3_close(pDb);
return ret;
}
static tnode_t *alloc_inode( extbmp_t *ebmp,
long long address_range_in_words,
word start,
long long limit )
{
tnode_t *retval;
assert( address_range_in_words > 0 );
retval = alloc_tnode( ebmp, tag_inode,
(sizeof( inode_t )
+ ebmp->entries_per_inode*sizeof( tnode_t* )));
retval->inode.address_range_in_words = address_range_in_words;
retval->inode.address_words_per_child =
CEILDIV( ((long long)address_range_in_words), ebmp->entries_per_inode );
assert( retval->inode.address_words_per_child > 0 );
assert((retval->inode.address_words_per_child
* ebmp->entries_per_inode)
>= retval->inode.address_range_in_words);
#if INCLUDE_REDUNDANT_FIELDS
retval->inode.start = start;
retval->inode.limit = limit;
#endif
init_inode_fields_cleared( ebmp, &retval->inode );
dbmsg( "alloc_inode(ebmp,%8lld,start=0x%08x,limit=0x%08llx)"
" ==> 0x%08x",
address_range_in_words, start, limit, retval);
return retval;
}
static tnode_t *alloc_leaf( extbmp_t *ebmp, word start, word limit )
{
tnode_t *retval;
ebmp->leaf_count += 1;
retval = alloc_tnode( ebmp, tag_leaf,
(sizeof( leaf_t )
+ ebmp->leaf_words*sizeof(word)));
assert( ((word*)start + (ADDRS_PER_WORD*ebmp->leaf_words)) == (word*)limit );
#if INCLUDE_REDUNDANT_FIELDS
retval->leaf.start = start;
retval->leaf.limit = limit;
#endif
init_leaf_fields_cleared( ebmp, &retval->leaf );
dbmsg( "alloc_leaf(ebmp,start=0x%08x,limit=0x%08x)"
" ==> 0x%08x",
start, limit, retval);
return retval;
}
/* split_node() - splits a full node in the B-tree into two separate nodes,
* possibly creating a new root node in the process
* should be no need to modify this function
*/
void split_node(p_tnode * ppnode, int * poffset) {
p_tnode pnode = *ppnode;
int median = pnode->nkeys>>1, i;
p_tnode parent = pnode->parent, split = alloc_tnode();
if (poffset != NULL) {
/* update offset index and ppnode to point to new insertion point */
if (*poffset > median) {
/* move to new (split) node */
*poffset -= (median+1);
*ppnode = split;
}
}
if (parent) {
int insert = find_index(pnode->keys[median],parent);
/* move median into parent */
for (i = parent->nkeys; i > insert; i--) {
parent->keys[i] = parent->keys[i-1];
parent->values[i] = parent->values[i-1];
parent->children[i+1] = parent->children[i];
}
parent->keys[insert] = pnode->keys[median];
parent->values[insert] = pnode->values[median];
parent->children[insert] = pnode;
parent->nkeys++;
/* move half from pnode into new node */
for (i = median + 1; i < pnode->nkeys; i++) {
split->keys[i-(median+1)] = pnode->keys[i];
split->values[i-(median+1)] = pnode->values[i];
}
for (i = median + 1; i < pnode->nkeys+1; i++) {
split->children[i-(median+1)] = pnode->children[i];
if (pnode->children[i] != NULL)
pnode->children[i]->parent = split;
pnode->children[i] = NULL;
}
split->nkeys = pnode->nkeys - (median+1);
pnode->nkeys = median;
parent->children[insert+1] = split;
split->parent = parent;
} else {
/* split root */
parent = ptreeroot = alloc_tnode();
parent->keys[0] = pnode->keys[median];
parent->values[0] = pnode->values[median];
parent->children[0] = pnode;
parent->nkeys = 1;
pnode->parent = parent;
/* move half from pnode into new node */
for (i = median + 1; i < pnode->nkeys; i++) {
split->keys[i-(median+1)] = pnode->keys[i];
split->values[i-(median+1)] = pnode->values[i];
}
for (i = median + 1; i < pnode->nkeys+1; i++) {
split->children[i-(median+1)] = pnode->children[i];
if (pnode->children[i] != NULL)
pnode->children[i]->parent = split;
pnode->children[i] = NULL;
}
split->nkeys = pnode->nkeys - (median+1);
pnode->nkeys = median;
parent->children[1] = split;
split->parent = parent;
}
}
