static void node_copy(struct node *left, struct node *right, int shift)
{
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
uint32_t value_size = le32_to_cpu(left->header.value_size);
BUG_ON(value_size != le32_to_cpu(right->header.value_size));
if (shift < 0) {
shift = -shift;
BUG_ON(nr_left + shift > le32_to_cpu(left->header.max_entries));
memcpy(key_ptr(left, nr_left),
key_ptr(right, 0),
shift * sizeof(__le64));
memcpy(value_ptr(left, nr_left, value_size),
value_ptr(right, 0, value_size),
shift * value_size);
} else {
BUG_ON(shift > le32_to_cpu(right->header.max_entries));
memcpy(key_ptr(right, 0),
key_ptr(left, nr_left - shift),
shift * sizeof(__le64));
memcpy(value_ptr(right, 0, value_size),
value_ptr(left, nr_left - shift, value_size),
shift * value_size);
}
}
/*
* Some little utilities for moving node data around.
*/
static void node_shift(struct node *n, int shift)
{
uint32_t nr_entries = le32_to_cpu(n->header.nr_entries);
uint32_t value_size = le32_to_cpu(n->header.value_size);
if (shift < 0) {
shift = -shift;
BUG_ON(shift > nr_entries);
BUG_ON((void *) key_ptr(n, shift) >= value_ptr(n, shift, value_size));
memmove(key_ptr(n, 0),
key_ptr(n, shift),
(nr_entries - shift) * sizeof(__le64));
memmove(value_ptr(n, 0, value_size),
value_ptr(n, shift, value_size),
(nr_entries - shift) * value_size);
} else {
BUG_ON(nr_entries + shift > le32_to_cpu(n->header.max_entries));
memmove(key_ptr(n, shift),
key_ptr(n, 0),
nr_entries * sizeof(__le64));
memmove(value_ptr(n, shift, value_size),
value_ptr(n, 0, value_size),
nr_entries * value_size);
}
}
void construct_value()const
{
if(!value_cted()){
/* value_ptr must be ==0, oherwise copy_value would have been called */
key_type k(*key_ptr());
key_ptr()->~key_type();
value_ptr= /* guarantees key won't be re-dted at ~rep_type if the */
static_cast<value_type*>(spc_ptr())+1; /* next statement throws */
value_ptr=new(spc_ptr())value_type(k);
}
}
/*
* FIXME: We shouldn't use a recursive algorithm when we have limited stack
* space. Also this only works for single level trees.
*/
static int walk_node(struct dm_btree_info *info, dm_block_t block,
int (*fn)(void *context, uint64_t *keys, void *leaf),
void *context)
{
int r;
unsigned i, nr;
struct dm_block *node;
struct btree_node *n;
uint64_t keys;
r = bn_read_lock(info, block, &node);
if (r)
return r;
n = dm_block_data(node);
nr = le32_to_cpu(n->header.nr_entries);
for (i = 0; i < nr; i++) {
if (le32_to_cpu(n->header.flags) & INTERNAL_NODE) {
r = walk_node(info, value64(n, i), fn, context);
if (r)
goto out;
} else {
keys = le64_to_cpu(*key_ptr(n, i));
r = fn(context, &keys, value_ptr(n, i));
if (r)
goto out;
}
}
out:
dm_tm_unlock(info->tm, node);
return r;
}
int Document::decrypt(lua_State* L)
{
// use the provided arg to look up the crypto keys.
lua_getglobal(L, "get_crypto_key");
lua_pushvalue(L, -2);
lua_call(L, 1, 1);
// Get the returned value. nil will cause an error bumping us out.
Bson_ro* val = Lunar<Bson_ro>::check(L, -1);
std::string key_name(as_string(L, -2));
// Create a copy of the data. It is possible that the pop below
// will cause the returned value to GC.
lj::bson::Binary_type bt;
uint32_t key_sz;
const uint8_t* key_data = lj::bson::as_binary(val->node(), &bt, &key_sz);
std::unique_ptr<uint8_t[], lj::Wiper<uint8_t[]> > key_ptr(new uint8_t[key_sz]);
key_ptr.get_deleter().set_count(key_sz);
memcpy(key_ptr.get(), key_data, key_sz);
lua_pop(L, 2);
try
{
doc_->decrypt(key_ptr.get(),
key_sz,
key_name);
}
catch (lj::Exception& ex)
{
lua_pushstring(L, ex.str().c_str());
lua_error(L);
}
return 0;
}
/*
* We dump as many entries from center as possible into left, then the rest
* in right, then rebalance2. This wastes some cpu, but I want something
* simple atm.
*/
static void delete_center_node(struct dm_btree_info *info, struct btree_node *parent,
struct child *l, struct child *c, struct child *r,
struct btree_node *left, struct btree_node *center, struct btree_node *right,
uint32_t nr_left, uint32_t nr_center, uint32_t nr_right)
{
uint32_t max_entries = le32_to_cpu(left->header.max_entries);
unsigned shift = min(max_entries - nr_left, nr_center);
BUG_ON(nr_left + shift > max_entries);
node_copy(left, center, -shift);
left->header.nr_entries = cpu_to_le32(nr_left + shift);
if (shift != nr_center) {
shift = nr_center - shift;
BUG_ON((nr_right + shift) > max_entries);
node_shift(right, shift);
node_copy(center, right, shift);
right->header.nr_entries = cpu_to_le32(nr_right + shift);
}
*key_ptr(parent, r->index) = right->keys[0];
delete_at(parent, c->index);
r->index--;
dm_tm_dec(info->tm, dm_block_location(c->block));
__rebalance2(info, parent, l, r);
}
static void __rebalance2(struct dm_btree_info *info, struct btree_node *parent,
struct child *l, struct child *r)
{
struct btree_node *left = l->n;
struct btree_node *right = r->n;
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
uint32_t nr_right = le32_to_cpu(right->header.nr_entries);
unsigned threshold = 2 * merge_threshold(left) + 1;
if (nr_left + nr_right < threshold) {
/*
* Merge
*/
node_copy(left, right, -nr_right);
left->header.nr_entries = cpu_to_le32(nr_left + nr_right);
delete_at(parent, r->index);
/*
* We need to decrement the right block, but not it's
* children, since they're still referenced by left.
*/
dm_tm_dec(info->tm, dm_block_location(r->block));
} else {
/*
* Rebalance.
*/
unsigned target_left = (nr_left + nr_right) / 2;
shift(left, right, nr_left - target_left);
*key_ptr(parent, r->index) = right->keys[0];
}
}
/*
* Delete a specific entry from a leaf node.
*/
static void delete_at(struct node *n, unsigned index, size_t value_size)
{
unsigned nr_entries = le32_to_cpu(n->header.nr_entries);
unsigned nr_to_copy = nr_entries - (index + 1);
if (nr_to_copy) {
memmove(key_ptr(n, index),
key_ptr(n, index + 1),
nr_to_copy * sizeof(__le64));
memmove(value_ptr(n, index, value_size),
value_ptr(n, index + 1, value_size),
nr_to_copy * value_size);
}
n->header.nr_entries = cpu_to_le32(nr_entries - 1);
}
void construct_value()const
{
if(!value_cted()){
/* value_ptr must be ==0, oherwise copy_value would have been called */
#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
key_type k(std::move(*key_ptr()));
#else
key_type k(*key_ptr());
#endif
key_ptr()->~key_type();
value_ptr= /* guarantees key won't be re-dted at ~rep_type if the */
static_cast<value_type*>(spc_ptr())+1; /* next statement throws */
value_ptr=new(spc_ptr())value_type(k);
}
}
int Document::encrypt(lua_State* L)
{
int top = lua_gettop(L);
// Every arg except the first is a path to encrypt
std::vector<std::string> paths;
if (top > 1)
{
paths.resize(top - 1);
while (top > 1)
{
// This code moves the item at lua index 2 and puts it
// in C index 0.
paths[top - 2] = as_string(L, -1);
lua_pop(L, 1);
top = lua_gettop(L);
}
}
// use the provided arg to look up the crypto keys.
lua_getglobal(L, "get_crypto_key");
lua_pushvalue(L, -2);
lua_call(L, 1, 1);
// Get the returned value. nil will cause an error bumping us out.
Bson_ro* val = Lunar<Bson_ro>::check(L, -1);
std::string key_name(as_string(L, -2));
// Create a copy of the data. It is possible that the pop below
// will cause the returned value to GC.
lj::bson::Binary_type bt;
uint32_t key_sz;
const uint8_t* key_data = lj::bson::as_binary(val->node(), &bt, &key_sz);
std::unique_ptr<uint8_t[], lj::Wiper<uint8_t[]> > key_ptr(new uint8_t[key_sz]);
key_ptr.get_deleter().set_count(key_sz);
memcpy(key_ptr.get(), key_data, key_sz);
lua_pop(L, 2);
try
{
// XXX Change this to get the server from somewhere.
doc_->encrypt(lj::Uuid::k_nil,
key_ptr.get(),
key_sz,
key_name,
paths);
}
catch (lj::Exception& ex)
{
lua_pushstring(L, ex.str().c_str());
lua_error(L);
}
return 0;
}
/*
* Redistributes entries among 3 sibling nodes.
*/
static void redistribute3(struct dm_btree_info *info, struct btree_node *parent,
struct child *l, struct child *c, struct child *r,
struct btree_node *left, struct btree_node *center, struct btree_node *right,
uint32_t nr_left, uint32_t nr_center, uint32_t nr_right)
{
int s;
uint32_t max_entries = le32_to_cpu(left->header.max_entries);
unsigned target = (nr_left + nr_center + nr_right) / 3;
BUG_ON(target > max_entries);
if (nr_left < nr_right) {
s = nr_left - target;
if (s < 0 && nr_center < -s) {
/* not enough in central node */
shift(left, center, nr_center);
s = nr_center - target;
shift(left, right, s);
nr_right += s;
} else
shift(left, center, s);
shift(center, right, target - nr_right);
} else {
s = target - nr_right;
if (s > 0 && nr_center < s) {
/* not enough in central node */
shift(center, right, nr_center);
s = target - nr_center;
shift(left, right, s);
nr_left -= s;
} else
shift(center, right, s);
shift(left, center, nr_left - target);
}
*key_ptr(parent, c->index) = center->keys[0];
*key_ptr(parent, r->index) = right->keys[0];
}
static void node_copy(struct node *left, struct node *right, int shift)
{
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
if (shift < 0) {
shift = -shift;
memcpy(key_ptr(left, nr_left),
key_ptr(right, 0),
shift * sizeof(__le64));
memcpy(value_ptr(left, nr_left, sizeof(__le64)),
value_ptr(right, 0, sizeof(__le64)),
shift * sizeof(__le64));
} else {
memcpy(key_ptr(right, 0),
key_ptr(left, nr_left - shift),
shift * sizeof(__le64));
memcpy(value_ptr(right, 0, sizeof(__le64)),
value_ptr(left, nr_left - shift, sizeof(__le64)),
shift * sizeof(__le64));
}
}
/*
* Some little utilities for moving node data around.
*/
static void node_shift(struct node *n, int shift)
{
uint32_t nr_entries = le32_to_cpu(n->header.nr_entries);
if (shift < 0) {
shift = -shift;
memmove(key_ptr(n, 0),
key_ptr(n, shift),
(nr_entries - shift) * sizeof(__le64));
memmove(value_ptr(n, 0, sizeof(__le64)),
value_ptr(n, shift, sizeof(__le64)),
(nr_entries - shift) * sizeof(__le64));
} else {
memmove(key_ptr(n, shift),
key_ptr(n, 0),
nr_entries * sizeof(__le64));
memmove(value_ptr(n, shift, sizeof(__le64)),
value_ptr(n, 0, sizeof(__le64)),
nr_entries * sizeof(__le64));
}
}
operator const key_type&()const
{
if(value_ptr)return key_from_value(*value_ptr);
else return *key_ptr();
}
~rep_type()
{
if(!value_ptr) key_ptr()->~key_type();
else if(value_cted())value_ptr->~value_type();
}
rep_type(const rep_type& x):value_ptr(x.value_ptr)
{
if(!x.value_ptr)new(key_ptr())key_type(*x.key_ptr());
}
