ErrorStack MasstreeStoragePimpl::verify_single_thread(thread::Thread* context) {
MasstreeIntermediatePage* layer_root;
WRAP_ERROR_CODE(get_first_root(context, false, &layer_root));
CHECK_AND_ASSERT(!layer_root->is_border()); // root of first layer is always intermediate page
CHECK_ERROR(verify_single_thread_layer(context, 0, layer_root));
return kRetOk;
}
///===============Follow a link in the page based on the name=======================///
void Browser::follow_link(std::string name_of_link_to_follow, int usertimeout=20)
{
if(links.size()==0)
{
std::cerr<<"\n[!] No links found\n";
return;
}
std::string to_follow="";
for(int i=0;i<links.size();i++)
{
if(links[i].name()==name_of_link_to_follow)
{
to_follow=links[i].url();
break;
}
}
if(to_follow=="")
{
std::cerr<<"\n[!] No such link in the page found\n";
return;
}
//if the link is already a complete one we open it directly else we add the site root
if(word_in(to_follow,"http://"))
{
open(to_follow,usertimeout);
}
else
{
std::string now_on = get_first_root();
//here we are on the last slash
if(to_follow[0]!='/')
{
open(now_on+to_follow);
}
else
{
open(now_on.substr(0,now_on.size()-1)+to_follow);
}
}
}
ErrorStack MasstreeStoragePimpl::fatify_first_root(
thread::Thread* context,
uint32_t desired_count) {
LOG(INFO) << "Masstree-" << get_name() << " being fatified for " << desired_count;
if (desired_count > kMaxIntermediatePointers) {
LOG(INFO) << "desired_count too large. adjusted to the max";
desired_count = kMaxIntermediatePointers;
}
// Check if the volatile page is moved. If so, grow it.
while (true) {
MasstreeIntermediatePage* root;
WRAP_ERROR_CODE(get_first_root(context, true, &root));
if (root->has_foster_child()) {
// oh, the root page needs to grow
LOG(INFO) << "oh, the root page needs to grow";
WRAP_ERROR_CODE(grow_root(
context,
&get_first_root_pointer(),
&get_first_root_owner(),
&root));
// then retry
} else {
break;
}
}
while (true) {
// lock the first root.
xct::McsLockScope owner_scope(context, &get_first_root_owner());
LOG(INFO) << "Locked the root page owner address.";
MasstreeIntermediatePage* root;
WRAP_ERROR_CODE(get_first_root(context, true, &root));
PageVersionLockScope scope(context, root->get_version_address());
LOG(INFO) << "Locked the root page itself.";
if (root->has_foster_child()) {
LOG(WARNING) << "Mm, I thought I grew the root, but concurrent xct again moved it. "
<< " Gave up fatifying. Should be super-rare.";
return kRetOk;
}
ASSERT_ND(root->is_locked());
ASSERT_ND(!root->is_moved());
uint32_t current_count = count_children(root);
LOG(INFO) << "Masstree-" << get_name() << " currently has " << current_count << " children";
if (current_count >= desired_count || current_count >= (kMaxIntermediatePointers / 2U)) {
LOG(INFO) << "Already enough fat. Done";
break;
}
LOG(INFO) << "Splitting...";
CHECK_ERROR(fatify_first_root_double(context));
WRAP_ERROR_CODE(get_first_root(context, true, &root));
uint32_t new_count = count_children(root);
if (new_count == current_count) {
LOG(INFO) << "Seems like we can't split any more.";
break;
}
}
return kRetOk;
}
ErrorStack MasstreeStoragePimpl::fatify_first_root_double(thread::Thread* context) {
MasstreeIntermediatePage* root;
WRAP_ERROR_CODE(get_first_root(context, true, &root));
ASSERT_ND(root->is_locked());
ASSERT_ND(!root->is_moved());
// assure that all children have volatile version
for (MasstreeIntermediatePointerIterator it(root); it.is_valid(); it.next()) {
if (it.get_pointer().volatile_pointer_.is_null()) {
MasstreePage* child;
WRAP_ERROR_CODE(follow_page(
context,
true,
const_cast<DualPagePointer*>(&it.get_pointer()),
&child));
}
ASSERT_ND(!it.get_pointer().volatile_pointer_.is_null());
}
std::vector<Child> original_children = list_children(root);
ASSERT_ND(original_children.size() * 2U <= kMaxIntermediatePointers);
std::vector<Child> new_children;
for (const Child& child : original_children) {
CHECK_ERROR(split_a_child(context, root, child, &new_children));
}
ASSERT_ND(new_children.size() >= original_children.size());
memory::NumaCoreMemory* memory = context->get_thread_memory();
memory::PagePoolOffset new_offset = memory->grab_free_volatile_page();
if (new_offset == 0) {
return ERROR_STACK(kErrorCodeMemoryNoFreePages);
}
// from now on no failure (we grabbed a free page).
VolatilePagePointer new_pointer = combine_volatile_page_pointer(
context->get_numa_node(),
kVolatilePointerFlagSwappable, // pointer to root page might be swapped!
get_first_root_pointer().volatile_pointer_.components.mod_count + 1,
new_offset);
MasstreeIntermediatePage* new_root
= context->resolve_newpage_cast<MasstreeIntermediatePage>(new_pointer);
new_root->initialize_volatile_page(
get_id(),
new_pointer,
0,
root->get_btree_level(), // same as current root. this is not grow_root
kInfimumSlice,
kSupremumSlice);
// no concurrent access to the new page, but just for the sake of assertion in the func.
PageVersionLockScope new_scope(context, new_root->get_version_address());
new_root->split_foster_migrate_records_new_first_root(&new_children);
ASSERT_ND(count_children(new_root) == new_children.size());
verify_new_root(context, new_root, new_children);
// set the new first-root pointer.
assorted::memory_fence_release();
get_first_root_pointer().volatile_pointer_.word = new_pointer.word;
// first-root snapshot pointer is unchanged.
// old root page and the direct children are now retired
assorted::memory_fence_acq_rel();
root->set_moved(); // not quite moved, but assertions assume that.
root->set_retired();
context->collect_retired_volatile_page(
construct_volatile_page_pointer(root->header().page_id_));
for (const Child& child : original_children) {
MasstreePage* original_page = context->resolve_cast<MasstreePage>(child.pointer_);
if (original_page->is_moved()) {
PageVersionLockScope scope(context, original_page->get_version_address());
original_page->set_retired();
context->collect_retired_volatile_page(child.pointer_);
} else {
// This means, the page had too small records to split. We must keep it.
}
}
assorted::memory_fence_acq_rel();
LOG(INFO) << "Split done. " << original_children.size() << " -> " << new_children.size();
return kRetOk;
}
