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bztree.h
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#ifndef BZTREE_H
#define BZTREE_H
#include <thread>
#include <vector>
#include <tuple>
#include <algorithm>
#include <queue>
#include "bzerrno.h"
#include "PMwCAS.h"
#include "utils.h"
#include <mutex>
#include <fstream>
//Consolidation types
#define BZ_SPLIT 1
#define BZ_MERGE 2
#define BZ_CONSOLIDATE 3
#define BZ_FROZEN 4
//Action types
#define BZ_ACTION_INSERT 1
#define BZ_ACTION_DELETE 2
#define BZ_ACTION_UPDATE 3
#define BZ_ACTION_UPSERT 4
#define BZ_ACTION_READ 5
//Node types
const uint64_t BZ_KEY_MAX = 0xdeadbeafdeadbeaf;
#define BZ_TYPE_LEAF 1
#define BZ_TYPE_NON_LEAF 2
template<typename Key, typename Val>
struct bz_tree;
//Print
#include <iomanip>
std::mutex mylock;
std::fstream fs("log.txt", std::ios::app);
/* BzTree节点头部 */
//如果是叶节点，则Val代表实际数据的类型，否则Val为uint64_t，代表孩子节点的相对指针
template<typename Key, typename Val>
struct bz_node
{
/* length 32: node size, 31: sorted count, 1: is_leaf */
uint64_t length_;
/* status 3: PMwCAS control, 1: frozen, 16: record count, 22: block size, 22: delete size */
uint64_t status_;
/* record meta entry 3: PMwCAS control, 1: visiable, 28: offset, 16: key length, 16: total length */
uint64_t * rec_meta_arr();
/* K-V getter and setter */
Key * get_key(uint64_t meta);
void set_key(uint32_t offset, const Key * key);
void copy_key(Key * dst, const Key * src);
Val * get_value(uint64_t meta);
void set_value(uint32_t offset, const Val * val);
void copy_value(Val * dst, const Val * src);
/* 键值比较函数 */
int key_cmp(uint64_t meta_1, const Key * key);
bool key_cmp_meta(uint64_t meta_1, uint64_t meta_2);
/* 辅助函数 */
/* 基本操作 */
uint32_t binary_search(const Key * key, int size = 0, uint64_t * meta_arr = nullptr);
bool find_key_sorted(const Key * key, uint32_t &pos);
bool find_key_unsorted(const Key * key, uint64_t status_rd, uint32_t alloc_epoch, uint32_t &pos, bool &recheck);
uint64_t status_add_rec_blk(uint64_t status_rd, uint32_t total_size);
uint64_t status_del(uint64_t status_rd, uint32_t total_size);
template<typename TreeVal>
bool add_dele_sz(bz_tree<Key, TreeVal> * tree, uint32_t total_size);
uint64_t status_frozen(uint64_t status_rd);
uint64_t meta_vis_off(uint64_t meta_rd, bool set_vis, uint32_t new_offset);
uint64_t meta_vis_off_klen_tlen(uint64_t meta_rd, bool set_vis, uint32_t new_offset, uint32_t key_size, uint32_t total_size);
void copy_data(uint32_t new_offset, const Key * key, const Val * val, uint32_t key_size, uint32_t total_size);
void copy_data(uint64_t meta_rd, std::vector<std::pair<std::shared_ptr<Key>, std::shared_ptr<Val>>> & res);
template<typename TreeVal>
int rescan_unsorted(bz_tree<Key, TreeVal> * tree, uint32_t beg_pos, uint32_t rec_cnt, const Key * key, uint32_t total_size, uint32_t alloc_epoch);
/* SMO辅助函数 */
int triger_consolidate();
uint32_t copy_node_to(rel_ptr<bz_node<Key, Val>> dst, uint64_t status_rd = 0);
void fr_sort_meta();
void fr_remove_meta(int pos);
int fr_insert_meta(const Key * key, uint64_t left, uint32_t key_sz, uint64_t right);
int fr_root_init(const Key * key, uint64_t left, uint32_t key_sz, uint64_t right);
uint32_t copy_sort_meta_to(rel_ptr<bz_node<Key, Val>> dst);
uint32_t copy_payload_to(rel_ptr<bz_node<Key, Val>> dst, uint32_t new_rec_cnt);
void init_header(rel_ptr<bz_node<Key, Val>> dst, uint32_t new_rec_cnt, uint32_t blk_sz, int leaf_opt = 0, uint32_t dele_sz = 0);
uint32_t valid_block_size(uint64_t status_rd = 0);
uint32_t valid_node_size(uint64_t status_rd = 0);
uint32_t valid_record_count(uint64_t status_rd = 0);
uint32_t fr_get_balanced_count(rel_ptr<bz_node<Key, Val>> dst);
rel_ptr<uint64_t> nth_child(int n);
Key * nth_key(int n);
Val * nth_val(int n);
template<typename TreeVal>
mdesc_t try_freeze(bz_tree<Key, TreeVal> * tree);
template<typename TreeVal>
bool unfreeze(bz_tree<Key, TreeVal> * tree);
template<typename TreeVal>
int consolidate(bz_tree<Key, TreeVal> * tree, rel_ptr<uint64_t> parent_status, rel_ptr<uint64_t> parent_ptr);
template<typename TreeVal>
int split(bz_tree<Key, TreeVal> * tree, rel_ptr<bz_node<Key, uint64_t>> parent, rel_ptr<uint64_t> grandpa_status, rel_ptr<uint64_t> grandpa_ptr);
template<typename TreeVal>
int merge(bz_tree<Key, TreeVal> * tree, int child_id, rel_ptr<bz_node<Key, uint64_t>> parent, rel_ptr<uint64_t> grandpa_status, rel_ptr<uint64_t> grandpa_ptr);
/* 执行叶节点的数据项操作 */
template<typename TreeVal>
int insert(bz_tree<Key, TreeVal> * tree, const Key * key, const Val * val, uint32_t key_size, uint32_t total_size, uint32_t alloc_epoch);
template<typename TreeVal>
int remove(bz_tree<Key, TreeVal> * tree, const Key * key);
template<typename TreeVal>
int update(bz_tree<Key, TreeVal> * tree, const Key * key, const Val * val, uint32_t key_size, uint32_t total_size, uint32_t alloc_epoch);
template<typename TreeVal>
int read(bz_tree<Key, TreeVal> * tree, const Key * key, Val * buffer, uint32_t max_val_size);
template<typename TreeVal>
int upsert(bz_tree<Key, TreeVal> * tree, const Key * key, const Val * val, uint32_t key_size, uint32_t total_size, uint32_t alloc_epoch);
std::vector<std::pair<std::shared_ptr<Key>, std::shared_ptr<Val>>> range_scan(const Key * beg_key, const Key * end_key);
void print_log(const char * action, const Key * k = nullptr, uint64_t ret = -1, bool pr =
#ifdef BZ_DEBUG
true
#else
false
#endif // BZ_DEBUG
);
};
/* BzTree */
template<typename Key, typename Val>
struct bz_tree {
PMEMobjpool * pop_;
pmwcas_pool pool_;
uint64_t root_;
uint32_t epoch_;
void first_use(PMEMobjpool * pop, PMEMoid base_oid);
int init(PMEMobjpool * pop, PMEMoid base_oid);
void recovery();
void finish();
int insert(const Key * key, const Val * val, uint32_t key_size, uint32_t total_size);
int remove(const Key * key);
int update(const Key * key, const Val * val, uint32_t key_size, uint32_t total_size);
int upsert(const Key * key, const Val * val, uint32_t key_size, uint32_t total_size);
int read(const Key * key, Val * buffer, uint32_t max_val_size);
/* 辅助函数 */
void register_this();
bool acquire_wr(bz_path_stack * path_stack);
void acquire_rd();
void release();
template<typename NType>
bool smo(bz_path_stack * path_stack, int & ret);
int new_root();
int traverse(int action, bool wr, const Key * key, const Val * val = nullptr, uint32_t key_size = 0, uint32_t total_size = 0, Val * buffer = nullptr, uint32_t max_val_size = 0);
template<typename NType>
rel_ptr<rel_ptr<bz_node<Key, NType>>> alloc_node(mdesc_t mdesc, int magic = 0);
mdesc_t alloc_mdesc(int recycle = 0);
void recycle_node(rel_ptr<rel_ptr<uint64_t>> ptr);
int pack_pmwcas(std::vector<std::tuple<rel_ptr<uint64_t>, uint64_t, uint64_t>> casn);
void print_node(uint64_t ptr, int extra);
void print_tree(bool pr =
#ifdef BZ_DEBUG
true
#else
false
#endif // BZ_DEBUG
);
void print_dfs(uint64_t ptr, int level);
};
template<typename Key, typename Val>
int bz_tree<Key, Val>::traverse(int action, bool wr, const Key * key, const Val * val, uint32_t key_size, uint32_t total_size, Val * buffer, uint32_t max_val_size)
{
register_this();
if (!pmwcas_read(&root_)) {
new_root();
}
bz_path_stack path_stack;
int retry = 0;
while (true)
{
path_stack.reset();
uint64_t root = pmwcas_read(&root_);
path_stack.push(root, -1);
while (true)
{
if (wr && acquire_wr(&path_stack)) {
break;
}
else if (!wr) {
acquire_rd();
}
uint64_t ptr = path_stack.get_node();
if (is_leaf_node(ptr)) {
rel_ptr<bz_node<Key, Val>> node(ptr);
int ret;
if (action == BZ_ACTION_INSERT)
ret = node->insert(this, key, val, key_size, total_size, epoch_);
else if (action == BZ_ACTION_DELETE)
ret = node->remove(this, key);
else if (action == BZ_ACTION_UPDATE)
ret = node->update(this, key, val, key_size, total_size, epoch_);
else if (action == BZ_ACTION_UPSERT)
ret = node->upsert(this, key, val, key_size, total_size, epoch_);
else
ret = node->read(this, key, buffer, max_val_size);
release();
if (ret == EPMWCASALLOC || ret == EFROZEN) {
std::this_thread::sleep_for(std::chrono::milliseconds(++retry));
break;
}
return ret;
}
else {
rel_ptr<bz_node<Key, uint64_t>> node(ptr);
int child_id = (int)node->binary_search(key);
uint64_t next = *node->nth_val(child_id);
while (next & MwCAS_BIT || next & RDCSS_BIT || next & DIRTY_BIT) {
std::this_thread::sleep_for(std::chrono::milliseconds(1));
next = *node->nth_val(child_id);
//assert(0);
//node->print_log("READ_BUG");
}
path_stack.push(next, child_id);
release();
}
}
}
}
template<typename Key, typename Val>
inline void bz_tree<Key, Val>::register_this()
{
gc_register(pool_.gc);
}
/* 检查是否需要调整节点结构 & 进入GC临界区 */
/* @param path_stack <节点相对地址, 父节点到孩子指针的相对地址> */
template<typename Key, typename Val>
bool bz_tree<Key, Val>::acquire_wr(bz_path_stack * path_stack)
{
//访问节点
gc_crit_enter(pool_.gc);
//检查是否需要结构调整SMO
bool smo_type;
int ret;
uint64_t ptr = path_stack->get_node();
if (is_leaf_node(ptr)) {
smo_type = smo<Val>(path_stack, ret);
}
else {
smo_type = smo<uint64_t>(path_stack, ret);
}
if (smo_type) {
gc_crit_exit(pool_.gc);
}
if (ret == EFROZEN || ret == EPMWCASALLOC) {
std::this_thread::sleep_for(std::chrono::milliseconds(1));
}
return smo_type;
}
/* 进入GC临界区 */
template<typename Key, typename Val>
inline void bz_tree<Key, Val>::acquire_rd()
{
//进入节点
gc_crit_enter(pool_.gc);
}
template<typename Key, typename Val>
inline void bz_tree<Key, Val>::release()
{
//退出节点
gc_crit_exit(pool_.gc);
}
template<typename Key, typename Val>
template<typename NType>
bool bz_tree<Key, Val>::smo(bz_path_stack * path_stack, int & ret)
{
rel_ptr<bz_node<Key, NType>> node(path_stack->get_node());
int child_id = path_stack->get_child_id();
int smo_type = node->triger_consolidate();
if (smo_type == BZ_CONSOLIDATE) {
CONSOLIDATE_TAG:
if (child_id < 0) {
ret = node->consolidate<Val>(this, rel_ptr<uint64_t>::null(), rel_ptr<uint64_t>::null());
}
else {
path_stack->pop();
rel_ptr<bz_node<Key, uint64_t>> parent(path_stack->get_node());
ret = node->consolidate<Val>(this, &parent->status_, parent->nth_val(child_id));
path_stack->push();
}
}
else if (smo_type == BZ_SPLIT) {
if (child_id < 0) {
ret = node->split<Val>(this, rel_ptr<bz_node<Key, uint64_t>>::null(),
rel_ptr<uint64_t>::null(), rel_ptr<uint64_t>::null());
}
else {
path_stack->pop();
rel_ptr<bz_node<Key, uint64_t>> parent(path_stack->get_node());
int grand_id = path_stack->get_child_id();
if (grand_id < 0) {
ret = node->split<Val>(this, parent, rel_ptr<uint64_t>::null(), rel_ptr<uint64_t>::null());
}
else {
path_stack->pop();
rel_ptr<bz_node<Key, uint64_t>> grandpa(path_stack->get_node());
ret = node->split<Val>(this, parent, &grandpa->status_, grandpa->nth_val(grand_id));
path_stack->push();
}
path_stack->push();
}
}
else if (smo_type == BZ_MERGE) {
if (child_id < 0)
goto CONSOLIDATE_TAG;
path_stack->pop();
rel_ptr<bz_node<Key, uint64_t>> parent(path_stack->get_node());
int grand_id = path_stack->get_child_id();
if (grand_id < 0) {
ret = node->merge<Val>(this, child_id, parent, rel_ptr<uint64_t>::null(), rel_ptr<uint64_t>::null());
}
else {
path_stack->pop();
rel_ptr<bz_node<Key, uint64_t>> grandpa(path_stack->get_node());
ret = node->merge<Val>(this, child_id, parent, &grandpa->status_, grandpa->nth_val(grand_id));
path_stack->push();
}
path_stack->push();
}
return smo_type && (ret == EFROZEN || !ret || ret == EPMWCASALLOC);
}
template<typename Key, typename Val>
template<typename NType>
rel_ptr<rel_ptr<bz_node<Key, NType>>> bz_tree<Key, Val>::alloc_node(mdesc_t mdesc, int magic)
{
rel_ptr<rel_ptr<bz_node<Key, NType>>> new_node_ptr =
pmwcas_reserve<bz_node<Key, NType>>(mdesc,
get_magic(&pool_, magic), 0, NOCAS_RELEASE_NEW_ON_FAILED);
pool_.mem_.acquire(new_node_ptr);
uint32_t node_sz = NODE_ALLOC_SIZE;
rel_ptr<bz_node<Key, NType>> node = *new_node_ptr;
memset(node.abs(), 0, sizeof(bz_node<Key, NType>));
set_node_size(node->length_, node_sz);
persist(node.abs(), sizeof(bz_node<uint64_t, uint64_t>));
return new_node_ptr;
/*
//原子分配空间
TX_BEGIN(pop_) {
pmemobj_tx_add_range_direct(new_node_ptr.abs(), sizeof(uint64_t));
*new_node_ptr = pmemobj_tx_alloc(NODE_ALLOC_SIZE, TOID_TYPE_NUM(struct bz_node_fake));
} TX_END;
assert(!new_node_ptr->is_null());
rel_ptr<bz_node<Key, Val>> new_node = *new_node_ptr;
memset(new_node.abs(), 0, NODE_ALLOC_SIZE);
set_node_size(new_node->length_, NODE_ALLOC_SIZE);
return new_node;
*/
}
template<typename Key, typename Val>
int bz_node<Key, Val>::triger_consolidate()
{
uint64_t status_rd = pmwcas_read(&status_);
if (is_frozen(status_rd))
return BZ_FROZEN;
uint32_t rec_cnt = get_record_count(status_rd);
uint32_t blk_sz = get_block_size(status_rd);
uint32_t dele_sz = get_delete_size(status_rd);
uint32_t node_sz = get_node_size(length_);
uint32_t free_sz = node_sz - blk_sz - sizeof(*this) - rec_cnt * sizeof(uint64_t);
if (free_sz <= NODE_MIN_FREE_SIZE || dele_sz >= NODE_MAX_DELETE_SIZE) {
uint32_t new_node_sz = valid_node_size(status_rd);
if (new_node_sz >= NODE_SPLIT_SIZE)
return BZ_SPLIT;
else if (new_node_sz <= NODE_MERGE_SIZE)
return BZ_MERGE;
else
return BZ_CONSOLIDATE;
}
return 0;
}
/*
merge N
1. choose N's left/right sibling if
1.1 shares the same parent
1.2 small enough to absorb N's records
2. if neither is ok, return false
3. freeze N and L status
4. allocate 2 new nodes:
4.1 new node N' contains N and L's records
4.2 N and L parent P' that swaps the child ptr to L to N'
5. 3-word PMwCAS
5.1 G's child ptr to P
5.2 G's status
5.3 freeze P
*/
template<typename Key, typename Val>
template<typename TreeVal>
int bz_node<Key, Val>::merge(bz_tree<Key, TreeVal> * tree, int child_id,
rel_ptr<bz_node<Key, uint64_t>> parent,
rel_ptr<uint64_t> grandpa_status, rel_ptr<uint64_t> grandpa_ptr)
{
/* Global Variables */
uint64_t status_parent;
uint64_t status_cur;
uint64_t status_sibling;
int sibling_type = 0; //-1: 左 1: 右
rel_ptr<bz_node<Key, Val>> sibling;
rel_ptr<rel_ptr<bz_node<Key, Val>>> new_node_ptr;
rel_ptr<rel_ptr<bz_node<Key, uint64_t>>> new_parent_ptr;
uint32_t child_max;
int ret = 0;
bool forbids[2] = { false, false };
mdesc_t mdesc = try_freeze<TreeVal>(tree);
if (mdesc.is_null())
return EFROZEN;
//寻找兄弟节点
while (true) {
sibling_type = 0;
//读当前节点
status_cur = pmwcas_read(&status_);
//如果没有数据，删除节点
uint32_t valid_rec_cnt = valid_record_count(status_cur);
if (!valid_rec_cnt) {
if (!parent.is_null()) {
//读父节点，为后续做准备
status_parent = pmwcas_read(&parent->status_);
if (is_frozen(status_parent)) {
if (this->unfreeze(tree))
pmwcas_abort(mdesc);
return EFROZEN;
}
child_max = get_record_count(status_parent);
}
break;
}
//根节点无法merge
if (parent.is_null()) {
if (this->unfreeze(tree))
pmwcas_abort(mdesc);
else
return EPMWCASALLOC;
return ENONEED;
}
//读父节点
status_parent = pmwcas_read(&parent->status_);
if (is_frozen(status_parent)) {
if (this->unfreeze(tree))
pmwcas_abort(mdesc);
return EFROZEN;
}
child_max = get_record_count(status_parent);
uint32_t cur_sz = valid_node_size(status_cur);
//选择兄弟节点
if (!forbids[0] && child_id > 0) {
//判断左兄弟
sibling = parent->nth_child(child_id - 1);
status_sibling = pmwcas_read(&sibling->status_);
if (!is_frozen(status_sibling)) {
uint32_t left_sz = sibling->valid_node_size(status_sibling);
if (cur_sz + left_sz - sizeof(*this) < NODE_SPLIT_SIZE) {
sibling_type = -1;
}
}
else {
forbids[0] = true;
}
}
if (!forbids[1] && !sibling_type && (uint32_t)child_id + 1 < child_max) {
//判断右兄弟
sibling = parent->nth_child(child_id + 1);
status_sibling = pmwcas_read(&sibling->status_);
if (!is_frozen(status_sibling)) {
uint32_t right_sz = sibling->valid_node_size(status_sibling);
if (cur_sz + right_sz - sizeof(*this) < NODE_SPLIT_SIZE) {
sibling_type = 1;
}
}
else {
forbids[1] = true;
}
}
if (!sibling_type) {
//没有合适的
if (this->unfreeze(tree))
pmwcas_abort(mdesc);
else
return EPMWCASALLOC;
return ENONEED;
}
//尝试freeze兄弟节点
uint64_t status_sibling_new = status_frozen(status_sibling);
pmwcas_add(mdesc, &sibling->status_, status_sibling_new, status_sibling, NOCAS_EXECUTE_ON_FAILED);
int cas_res = tree->pack_pmwcas({{ &sibling->status_, status_sibling, status_sibling_new }});
if (!cas_res)
break;
print_log("MERGE-SIBLING_ERACE");
if (this->unfreeze(tree))
pmwcas_abort(mdesc);
else
return EPMWCASALLOC;
return ERACE;
}
print_log("MERGE_BEGIN", NULL, sibling.rel());
//删除根节点
if (parent.is_null()) {
pmwcas_add(mdesc, &tree->root_, rel_ptr<bz_node<Key, Val>>(this).rel(), 0, RELEASE_EXP_ON_SUCCESS);
if (!pmwcas_commit(mdesc))
return ERACE;
return 0;
}
//freeze old parent
uint64_t status_parent_new = status_frozen(status_parent);
pmwcas_add(mdesc, &parent->status_, status_parent, status_parent_new, 0);
if (sibling_type) {
/* 初始化N' */
new_node_ptr = tree->alloc_node<Val>(mdesc, 0);
rel_ptr<bz_node<Key, Val>> new_node = *new_node_ptr;
uint32_t new_blk_sz = 0;
uint32_t new_rec_cnt = 0;
//拷贝N和sibling的meta和k-v
this->copy_node_to(new_node);
uint32_t tot_rec_cnt = sibling->copy_node_to(new_node);
new_node->fr_sort_meta();
//初始化status和length
persist(new_node.abs(), NODE_ALLOC_SIZE);
}
rel_ptr<uint64_t> this_node((uint64_t*)this);
rel_ptr<uint64_t> sibling_addr(sibling);
if (child_max > 2
|| child_max == 2 && BZ_KEY_MAX != *(uint64_t*)parent->nth_key(1)
|| new_node_ptr.is_null())
{
//保留父亲节点
/* 初始化P' BEGIN */
new_parent_ptr = tree->alloc_node<uint64_t>(mdesc, 1);
rel_ptr<bz_node<Key, uint64_t>> new_parent = *new_parent_ptr;
uint32_t new_parent_rec_cnt = parent->copy_node_to(new_parent) - 1;
int pos = sibling_type < 0 ? child_id - 1 : child_id;
new_parent->fr_remove_meta(pos);
if (sibling_type)
*new_parent->nth_val(pos) = new_node_ptr->rel();
set_sorted_count(new_parent->length_, new_parent_rec_cnt);
persist(new_parent.abs(), NODE_ALLOC_SIZE);
//pmwcas
if (grandpa_ptr.is_null()) {
pmwcas_add(mdesc, &tree->root_, parent.rel(), new_parent.rel(), RELEASE_EXP_ON_SUCCESS);
}
else {
pmwcas_add(mdesc, grandpa_ptr, parent.rel(), new_parent.rel(), RELEASE_EXP_ON_SUCCESS);
uint64_t status_grandpa_rd = pmwcas_read(grandpa_status.abs());
if (is_frozen(status_grandpa_rd)) {
ret = EFROZEN;
goto IMMEDIATE_ABORT;
}
pmwcas_add(mdesc, grandpa_status, status_grandpa_rd, status_grandpa_rd);
}
}
else {
//删除父亲节点
if (grandpa_ptr.is_null()) {
pmwcas_add(mdesc, &tree->root_, parent.rel(), new_node_ptr->rel(), RELEASE_EXP_ON_SUCCESS);
}
else {
pmwcas_add(mdesc, grandpa_ptr, parent.rel(), new_node_ptr->rel(), RELEASE_EXP_ON_SUCCESS);
uint64_t status_grandpa_rd = pmwcas_read(grandpa_status.abs());
if (is_frozen(status_grandpa_rd)) {
ret = EFROZEN;
goto IMMEDIATE_ABORT;
}
pmwcas_add(mdesc, grandpa_status, status_grandpa_rd, status_grandpa_rd);
}
}
//释放当前节点和兄弟节点
pmwcas_add(mdesc, this_node, 0, 0, NOCAS_RELEASE_ADDR_ON_SUCCESS);
if (sibling_type) {
pmwcas_add(mdesc, sibling_addr, 0, 0, NOCAS_RELEASE_ADDR_ON_SUCCESS);
}
//执行pmwcas
if (!pmwcas_commit(mdesc)) {
ret = ERACE;
}
IMMEDIATE_ABORT:
pmwcas_free(mdesc);
print_log("MERGE_END", NULL, ret);
if (!ret) {
if (!new_node_ptr.is_null())
(*new_node_ptr)->print_log("MERGE_NEW");
if (!new_parent_ptr.is_null())
(*new_parent_ptr)->print_log("MERGE_NEW_PARENT");
}
return ret;
}
/*
split
1. freeze the node (k1, k2]
2. scan all valid keys and find the seperator key K
3. allocate 3 new nodes:
3.1 new N' (K, k2]
3.2 N' sibling O (k1, K]
3.3 N' new parent P' (add new key record K and ptr to O)
4. 3-word PMwCAS
4.1 freeze P status
4.2 swap G's ptr to P to P'
4.3 G's status to detect conflicts
NOTES:
Of new nodes, N' and O are not taken care of.
So we need an extra PMwCAS mdesc to record those memories:
in case failure before memory transmition, pmwcas will help reclaim;
in case success, abort the pmwcas since it has been safe.
*/
template<typename Key, typename Val>
template<typename TreeVal>
int bz_node<Key, Val>::split(
bz_tree<Key, TreeVal> * tree, rel_ptr<bz_node<Key, uint64_t>> parent,
rel_ptr<uint64_t> grandpa_status, rel_ptr<uint64_t> grandpa_ptr)
{
/* Global Variables */
uint64_t status_parent_rd;
int ret = 0;
mdesc_t mdesc = try_freeze<TreeVal>(tree);
if (mdesc.is_null())
return EFROZEN;
print_log("SPLIT_BEGIN");
/* 分配N'、O、P */
rel_ptr<rel_ptr<bz_node<Key, Val>>> new_left_ptr = tree->alloc_node<Val>(mdesc, 0);
rel_ptr<bz_node<Key, Val>> new_left = *new_left_ptr;
/* 初始化N'和O BEGIN */
//拷贝meta到new_left并按键值排序
uint32_t new_rec_cnt = this->copy_sort_meta_to(new_left);
if (new_rec_cnt < 2) {
pmwcas_free(mdesc);
print_log("SPLIT-NEW_REC_CNT");
return ENONEED;
}
rel_ptr<uint64_t> this_node_addr((uint64_t*)this);
//分配给O和P'
rel_ptr<rel_ptr<bz_node<Key, Val>>> new_right_ptr = tree->alloc_node<Val>(mdesc, 1);
rel_ptr<bz_node<Key, Val>> new_right = *new_right_ptr;
rel_ptr<rel_ptr<bz_node<Key, uint64_t>>> new_parent_ptr = tree->alloc_node<uint64_t>(mdesc, 2);
rel_ptr<bz_node<Key, uint64_t>> new_parent = *new_parent_ptr;
//按照大小平均分配键值对
uint32_t left_rec_cnt = this->fr_get_balanced_count(new_left);
//保证至少有一个到右节点
if (left_rec_cnt == new_rec_cnt) {
--left_rec_cnt;
}
uint32_t right_rec_cnt = new_rec_cnt - left_rec_cnt;
//拷贝meta到new_right
memcpy(new_right->rec_meta_arr(), new_left->rec_meta_arr() + left_rec_cnt,
right_rec_cnt * sizeof(uint64_t));
//拷贝k-v payload
uint32_t left_blk_sz = this->copy_payload_to(new_left, left_rec_cnt);
uint32_t right_blk_sz = this->copy_payload_to(new_right, right_rec_cnt);
//初始化status和length
this->init_header(new_left, left_rec_cnt, left_blk_sz);
this->init_header(new_right, right_rec_cnt, right_blk_sz);
//持久化
persist(new_left.abs(), NODE_ALLOC_SIZE);
persist(new_right.abs(), NODE_ALLOC_SIZE);
/* 初始化 N'和O END */
/* 初始化P' BEGIN */
//获得分割键值K
uint64_t meta_key = new_left->rec_meta_arr()[left_rec_cnt - 1];
const Key * K = new_left->get_key(meta_key);
uint32_t key_sz = get_key_length(meta_key);
uint32_t tot_sz = key_sz + sizeof(uint64_t);
uint64_t V = new_left.rel();
uint64_t * parent_meta_arr = new_parent->rec_meta_arr();
if (!parent.is_null()) {
/* 如果当前节点是非根节点 */
status_parent_rd = pmwcas_read(&parent->status_);
if (is_frozen(status_parent_rd)) {
ret = EFROZEN;
goto IMMEDIATE_ABORT;
}
uint32_t new_parent_rec_cnt = parent->copy_node_to(new_parent, status_parent_rd);
if (ret = new_parent->fr_insert_meta(K, V, key_sz, new_right.rel()))
goto IMMEDIATE_ABORT;
//持久化
persist(new_parent.abs(), NODE_ALLOC_SIZE);
}
else {
/* 如果当前节点是根节点 */
if (ret = new_parent->fr_root_init(K, V, key_sz, new_right.rel()))
goto IMMEDIATE_ABORT;
persist(new_parent.abs(), NODE_ALLOC_SIZE);
}
/* 初始化P' END */
/* 3-word pmwcas */
if (!grandpa_ptr.is_null()) {
/* 存在祖父节点 */
//3.1 G's ptr to P -> P'
pmwcas_add(mdesc, grandpa_ptr, parent.rel(), new_parent.rel(), RELEASE_EXP_ON_SUCCESS);
//3.2 freeze P's status
uint64_t status_parent_new = status_frozen(status_parent_rd);
pmwcas_add(mdesc, &parent->status_, status_parent_rd, status_parent_new);
//3.3 make sure G's status is not frozen
uint64_t status_grandpa_rd = pmwcas_read(grandpa_status.abs());
if (is_frozen(status_grandpa_rd)) {
ret = EFROZEN;
goto IMMEDIATE_ABORT;
}
pmwcas_add(mdesc, grandpa_status, status_grandpa_rd, status_grandpa_rd);
pmwcas_add(mdesc, this_node_addr, 0, 0, NOCAS_RELEASE_ADDR_ON_SUCCESS);
}
else if (!parent.is_null()) {
/* 父节点是根节点 */
//3.1 root's ptr to P -> P'
pmwcas_add(mdesc, &tree->root_, parent.rel(), new_parent.rel(), RELEASE_EXP_ON_SUCCESS);
//3.2 freeze P's status
uint64_t status_parent_new = status_frozen(status_parent_rd);
pmwcas_add(mdesc, &parent->status_, status_parent_rd, status_parent_new);
pmwcas_add(mdesc, this_node_addr, 0, 0, NOCAS_RELEASE_ADDR_ON_SUCCESS);
}
else {
/* 当前节点是根节点 */
rel_ptr<bz_node<Key, Val>> cur_ptr = this;
pmwcas_add(mdesc, &tree->root_, cur_ptr.rel(), new_parent.rel(), RELEASE_EXP_ON_SUCCESS);
}
//执行pmwcas
if (!pmwcas_commit(mdesc)) {
ret = ERACE;
}
IMMEDIATE_ABORT:
pmwcas_free(mdesc);
print_log("SPLIT_END", NULL, ret);
if (!ret) {
string msg = "SPLIT";
if (!grandpa_ptr.is_null())
msg += "_3_";
else if (!parent.is_null())
msg += "_2_";
else
msg += "_1_";
new_left->print_log(string(msg + "NEW_LEFT").c_str(), nullptr, left_rec_cnt);
new_right->print_log(string(msg + "NEW_RIGHT").c_str(), nullptr, right_rec_cnt);
new_parent->print_log(string(msg + "NEW_PARENT").c_str());
}
return ret;
}
/*
consolidate:
trigger by
either free space too small or deleted space too large
1) single-word PMwCAS on status => frozen bit
2) scan all valid records(visiable and not deleted)
calculate node size = record size + free space
2.1) if node size too large, do a split
2.2) otherwise, allocate a new node N', copy records sorted, init header
3) use path stack to find Node's parent P
3.1) if P's frozen, retraverse to locate P
4) 2-word PMwCAS
r in P that points to N => N'
P's status => detect concurrent freeze
5) N is ready for gc
6)
*/
template<typename Key, typename Val>
template<typename TreeVal>
int bz_node<Key, Val>::consolidate(bz_tree<Key, TreeVal> * tree,
rel_ptr<uint64_t> parent_status, rel_ptr<uint64_t> parent_ptr)
{
int ret = 0;
mdesc_t mdesc = try_freeze<TreeVal>(tree);
if (mdesc.is_null())
return EFROZEN;
print_log("CONSOLIDATE_BEGIN");
//初始化节点内容为0
rel_ptr<rel_ptr<bz_node<Key, Val>>> node_ptr = tree->alloc_node<Val>(mdesc);
rel_ptr<bz_node<Key, Val>> node = *node_ptr;
this->copy_node_to(node);
node->fr_sort_meta();
//持久化
persist(node.abs(), NODE_ALLOC_SIZE);
rel_ptr<bz_node<Key, Val>> this_node(this);
//如果需要修改父节点，确保其Frozen != 0
if (!parent_ptr.is_null()) {
uint64_t status_rd = pmwcas_read(parent_status.abs());
if (is_frozen(status_rd)) {
ret = EFROZEN;
goto IMMEDIATE_ABORT;
}
pmwcas_add(mdesc, parent_status, status_rd, status_rd, 0);
pmwcas_add(mdesc, parent_ptr, this_node.rel(), node.rel(), RELEASE_EXP_ON_SUCCESS);
}
else {
pmwcas_add(mdesc, &tree->root_, this_node.rel(), node.rel(), RELEASE_EXP_ON_SUCCESS);
}
//执行pmwcas
if (!pmwcas_commit(mdesc))
ret = ERACE;
IMMEDIATE_ABORT:
pmwcas_free(mdesc);
print_log("CONSOLIDATE_END", NULL, ret);
if (!ret) {
node->print_log("CONSOLIDATE_NEW");
}
return ret;
}
/* 计算节点均分时坐节点的数据项个数，单线程调用 */
template<typename Key, typename Val>
uint32_t bz_node<Key, Val>::fr_get_balanced_count(rel_ptr<bz_node<Key, Val>> dst)
{
uint32_t old_blk_sz = valid_block_size();
uint64_t * meta_arr = dst->rec_meta_arr();
uint32_t left_rec_cnt = 0;
for (uint32_t i = 0, acc_sz = 0; acc_sz < old_blk_sz / 2; ++i) {
if (is_visiable(meta_arr[i])) {
++left_rec_cnt;
acc_sz += get_total_length(meta_arr[i]);
}
}
return left_rec_cnt;
}
template<typename Key, typename Val>
uint32_t bz_node<Key, Val>::copy_node_to(rel_ptr<bz_node<Key, Val>> dst, uint64_t status_rd)
{
if (!status_rd)
status_rd = pmwcas_read(&status_);
uint64_t * meta_arr = rec_meta_arr();
uint64_t * new_meta_arr = dst->rec_meta_arr();
uint32_t rec_cnt = get_record_count(status_rd);
uint32_t new_rec_cnt = get_record_count(dst->status_);
uint32_t new_blk_sz = get_block_size(dst->status_);
uint32_t new_node_sz = get_node_size(dst->length_);
for (uint32_t i = 0; i < rec_cnt; ++i) {
uint64_t meta_rd = pmwcas_read(&meta_arr[i]);
if (is_visiable(meta_rd)) {
const Key * key = get_key(meta_rd);
const Val * val = get_value(meta_rd);
//assert(*(uint64_t*)key < 65 || *(uint64_t*)key == BZ_KEY_MAX);
uint64_t tmp = *(uint64_t*)val;
if ((tmp & MwCAS_BIT || tmp & RDCSS_BIT || tmp & DIRTY_BIT)) {
std::this_thread::sleep_for(std::chrono::milliseconds(1));
uint64_t tt = *(uint64_t*)val;
assert(0);
}
uint32_t key_sz = get_key_length(meta_rd);
uint32_t tot_sz = get_total_length(meta_rd);
uint32_t offset = new_node_sz - new_blk_sz - tot_sz - 1;
new_meta_arr[new_rec_cnt] = meta_vis_off_klen_tlen(0, true, offset, key_sz, tot_sz);
dst->copy_data(offset, key, val, key_sz, tot_sz);
new_blk_sz += tot_sz;
++new_rec_cnt;
}
}
set_record_count(dst->status_, new_rec_cnt);
set_block_size(dst->status_, new_blk_sz);
if (is_leaf(length_)) {
set_leaf(dst->length_);
}
else {
set_non_leaf(dst->length_);
}
return new_rec_cnt;
}
template<typename Key, typename Val>
void bz_node<Key, Val>::fr_sort_meta()
{
uint64_t tot_rec_cnt = get_record_count(status_);
uint64_t * new_meta_arr = rec_meta_arr();
std::sort(new_meta_arr, new_meta_arr + tot_rec_cnt,
std::bind(&bz_node<Key, Val>::key_cmp_meta, this, std::placeholders::_1, std::placeholders::_2));
//计算有效meta数目
uint32_t new_rec_cnt = binary_search(nullptr, (int)tot_rec_cnt);
set_sorted_count(length_, new_rec_cnt);
set_record_count(status_, new_rec_cnt);
}
template<typename Key, typename Val>
inline void bz_node<Key, Val>::fr_remove_meta(int pos)
{
uint64_t * parent_meta_arr = rec_meta_arr();
uint32_t rec_cnt = get_record_count(status_);
uint32_t dele_sz = get_delete_size(status_);
memmove(parent_meta_arr + pos, parent_meta_arr + pos + 1, (rec_cnt - 1 - pos) * sizeof(uint64_t));
//增加delete size，减少rec_cnt
set_record_count(status_, rec_cnt - 1);
set_delete_size(status_, dele_sz + get_total_length(parent_meta_arr[pos]));
}
template<typename Key, typename Val>
inline int bz_node<Key, Val>::fr_insert_meta(const Key * K, uint64_t left, uint32_t key_sz, uint64_t right)
{
uint64_t * meta_arr = rec_meta_arr();
uint32_t tot_sz = key_sz + sizeof(uint64_t);
uint32_t rec_cnt = get_record_count(status_);
uint32_t blk_sz = get_block_size(status_);
uint32_t node_sz = get_node_size(length_);
uint32_t pos = binary_search(K, rec_cnt);
if ((rec_cnt + 2) * sizeof(uint64_t) + key_sz + blk_sz + sizeof(*this) > node_sz) {
return EALLOCSIZE;
}
memmove(meta_arr + pos + 1, meta_arr + pos, sizeof(uint64_t) * (rec_cnt - pos));
uint32_t key_offset = node_sz - blk_sz - tot_sz - 1;
meta_arr[pos] = meta_vis_off_klen_tlen(0, true, key_offset, key_sz, tot_sz);
this->copy_data(key_offset, K, &left, key_sz, tot_sz);
//修改原来指向N的指针，现在指向new_right
*get_value(meta_arr[pos + 1]) = right;
assert(!(right & MwCAS_BIT || right & RDCSS_BIT || right & DIRTY_BIT));
set_record_count(status_, rec_cnt + 1);
set_sorted_count(length_, rec_cnt + 1);
set_block_size(status_, blk_sz + tot_sz);
return 0;
}
template<typename Key, typename Val>
int bz_node<Key, Val>::fr_root_init(const Key * K, uint64_t left, uint32_t key_sz, uint64_t right)
{
uint64_t * meta_arr = rec_meta_arr();
uint32_t node_sz = get_node_size(length_);
uint32_t tot_sz = key_sz + sizeof(uint64_t);