commit e1f1e71f9ad0d23cf55e4c5bbc63d71eff0ca2e5
Author: taynpg <taynpg@163.com>
Date: Thu Apr 11 09:27:21 2024 +0800
first commit
diff --git a/.clang-format b/.clang-format
new file mode 100644
index 0000000..4ed25d6
--- /dev/null
+++ b/.clang-format
@@ -0,0 +1,17 @@
+# .clang-format
+
+# 风格格式化
+BasedOnStyle: Google
+# 4 空格缩进
+IndentWidth: 4
+# 连续对齐变量的声明
+AlignConsecutiveDeclarations: true
+# 指针左侧对齐
+PointerAlignment: Left
+# 访问说明符(public、private等)的偏移
+AccessModifierOffset: -4
+# 大括号
+BreakBeforeBraces: Custom
+BraceWrapping:
+ # 函数定义后面大括号在新行
+ AfterFunction: true
diff --git a/.clangd b/.clangd
new file mode 100644
index 0000000..a0851df
--- /dev/null
+++ b/.clangd
@@ -0,0 +1,7 @@
+Hover:
+ ShowAKA: Yes
+Diagnostics:
+ UnusedIncludes: None
+ Suppress: [anon_type_definition]
+ ClangTidy:
+ Remove: misc-unused-alias-decls
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..424542a
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,37 @@
+# Prerequisites
+*.d
+
+# Compiled Object files
+*.slo
+*.lo
+*.o
+*.obj
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Compiled Dynamic libraries
+*.so
+*.dylib
+*.dll
+
+# Fortran module files
+*.mod
+*.smod
+
+# Compiled Static libraries
+*.lai
+*.la
+*.a
+*.lib
+
+# Executables
+*.exe
+*.out
+*.app
+cmake-*
+build
+.vs
+.idea
+out
diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 0000000..e0cfb5f
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,35 @@
+{
+ "files.autoSave": "onFocusChange",
+ "editor.fontSize": 17,
+ "editor.fontFamily": "'Operator Mono Lig Light', 'Operator Mono Lig Light', 'Operator Mono Lig Light'",
+ "cmake.configureOnOpen": true,
+ "cmake.debugConfig": {
+ "console": "integratedTerminal"
+ },
+ "cmake.options.statusBarVisibility": "visible",
+ "cmake.generator": "Ninja",
+ "C_Cpp.intelliSenseEngine": "disabled",
+ "clangd.arguments": [
+ "--header-insertion=never",
+ "--all-scopes-completion",
+ "--completion-style=detailed",
+ "--clang-tidy",
+ "-j=4",
+ "--pch-storage=memory",
+ "--compile-commands-dir=build",
+ "--background-index",
+ "--ranking-model=heuristics",
+ "--query-driver=/usr/bin/g++"
+ ],
+ "editor.inlayHints.enabled": "off",
+ "editor.unicodeHighlight.allowedLocales": {
+ "ja": true,
+ "zh-hans": true
+ },
+ "files.associations": {
+ "iostream": "cpp"
+ },
+ "workbench.colorCustomizations": {
+ //"editor.background": "#C0C0C0"
+ }
+}
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..b6de43e
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,12 @@
+cmake_minimum_required(VERSION 3.8)
+project(skip_use)
+
+set(CMAKE_CXX_STANDARD 11)
+
+if (MSVC)
+ add_compile_options(/source-charset:utf-8)
+ add_compile_options(/EHsc)
+endif()
+
+add_executable(skip_use main.cpp MSkipList.hpp)
+add_executable(skip_test stress.cpp MSkipList.hpp)
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..6cfc697
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 taynpg
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/MSkipList.hpp b/MSkipList.hpp
new file mode 100644
index 0000000..09abcc5
--- /dev/null
+++ b/MSkipList.hpp
@@ -0,0 +1,243 @@
+#ifndef MSKIPLIST_HEADER
+#define MSKIPLIST_HEADER
+
+#include <atomic>
+#include <cassert>
+#include <random>
+#include <cstring>
+
+template <typename T, typename P>
+class SkipList {
+public:
+ // 插入数据
+ void insert(const T& key, const P& value);
+ // 删除数据
+ void remove(const T& key);
+ // 查询数据
+ bool search(const T& key, P& value);
+ // 是否包含某个数据
+ bool contains(const T& key);
+ // 当前表节点个数
+ std::size_t count() const;
+ // 清除表
+ void clear();
+
+public:
+ SkipList(int max_level = 12);
+ ~SkipList();
+
+private:
+ struct SkipNode;
+ std::size_t count_{};
+ SkipNode** pre_{};
+ SkipNode* header_{};
+ const int max_level_{}; // 限定的最大高度
+ std::atomic_int cur_max_height_{}; // 当前使用的最大高度
+ std::random_device rd_{};
+ std::mt19937 gen_{};
+ std::uniform_int_distribution<int> dis_{};
+
+private:
+ int random_level();
+ SkipNode* find_node(const T& key);
+};
+
+template <typename T, typename P>
+SkipList<T, P>::~SkipList()
+{
+ clear();
+ delete[] pre_;
+ delete header_;
+}
+
+template <typename T, typename P>
+void SkipList<T, P>::clear()
+{
+ SkipNode* start = header_->get_no_bar(0);
+ while (start) {
+ SkipNode* n = start;
+ start = start->get_no_bar(0);
+ delete n;
+ --count_;
+ }
+}
+
+template <typename T, typename P>
+inline int SkipList<T, P>::random_level()
+{
+ static const int base_ = 2;
+ int height = 1;
+ while (height < max_level_ && (dis_(gen_) % base_) == 0) {
+ ++height;
+ }
+ return height;
+}
+
+template <typename T, typename P>
+struct SkipList<T, P>::SkipNode {
+ T key_{};
+ P value_{};
+ int level_{};
+
+public:
+ explicit SkipNode(int level = 1) { alloc(level); }
+ ~SkipNode() { release(); }
+ SkipNode(const T& key, const P& value, int level)
+ {
+ key_ = key;
+ value_ = value;
+ alloc(level);
+ }
+ void alloc(int max_level)
+ {
+ if (max_level < 1) {
+ return;
+ }
+ release();
+ next_ = new std::atomic<SkipNode*>[max_level] {};
+ }
+ void release() { delete[] next_; }
+ SkipNode* get(int n)
+ {
+ assert(n >= 0);
+ return next_[n].load(std::memory_order_acquire);
+ }
+ SkipNode* get_no_bar(int n)
+ {
+ assert(n >= 0);
+ return next_[n].load(std::memory_order_relaxed);
+ }
+ void set(int n, SkipNode* node)
+ {
+ assert(n >= 0);
+ next_[n].store(node, std::memory_order_release);
+ }
+ void set_no_bar(int n, SkipNode* node)
+ {
+ assert(n >= 0);
+ next_[n].store(node, std::memory_order_relaxed);
+ }
+
+private:
+ std::atomic<SkipNode*>* next_{};
+};
+
+template <typename T, typename P>
+inline SkipList<T, P>::SkipList(int max_level)
+ : max_level_(max_level),
+ cur_max_height_(1),
+ gen_(rd_()),
+ dis_(0, std::numeric_limits<int>::max())
+{
+ assert(max_level_ > 0);
+ header_ = new SkipNode(max_level_);
+ pre_ = new SkipNode*[max_level_];
+}
+
+template <typename T, typename P>
+typename SkipList<T, P>::SkipNode* SkipList<T, P>::find_node(const T& key)
+{
+ memset(pre_, 0x0, sizeof(SkipNode*) * max_level_);
+ SkipNode* x = header_;
+ int level = cur_max_height_.load() - 1;
+ while (true) {
+ SkipNode* next = x->get(level);
+ if (next && next->key_ < key) {
+ x = next;
+ } else {
+ pre_[level] = x;
+ if (level == 0) {
+ return next;
+ } else {
+ --level;
+ }
+ }
+ }
+}
+
+template <typename T, typename P>
+inline bool SkipList<T, P>::contains(const T& key)
+{
+ SkipNode* x = find_node(key);
+ if (x && x->key_ == key) {
+ return true;
+ }
+ return false;
+}
+
+template <typename T, typename P>
+inline std::size_t SkipList<T, P>::count() const
+{
+ return count_;
+}
+
+template <typename T, typename P>
+inline void SkipList<T, P>::insert(const T& key, const P& value)
+{
+ SkipNode* x = find_node(key);
+
+ if (x && x->key_ == key) {
+ x->value_ = value;
+ return;
+ }
+
+ int height = random_level();
+ if (height > cur_max_height_) {
+ for (int i = cur_max_height_; i < height; ++i) {
+ pre_[i] = header_;
+ }
+ cur_max_height_.store(height, std::memory_order_relaxed);
+ }
+ x = new SkipNode(key, value, height);
+ for (int i = 0; i < height; ++i) {
+ x->set_no_bar(i, pre_[i]->get_no_bar(i));
+ pre_[i]->set(i, x);
+ }
+ ++count_;
+}
+
+template <typename T, typename P>
+inline void SkipList<T, P>::remove(const T& key)
+{
+ memset(pre_, 0x0, sizeof(SkipNode*) * max_level_);
+ SkipNode* x = header_;
+ SkipNode* purpose = nullptr;
+ int level = cur_max_height_.load() - 1;
+ while (true) {
+ if (level < 0) {
+ break;
+ }
+ SkipNode* next = x->get(level);
+ if (!next) {
+ --level;
+ continue;
+ }
+
+ if (next->key_ < key) {
+ x = next;
+ continue;
+ }
+
+ if (next->key_ == key) {
+ SkipNode* nx = next->get_no_bar(level);
+ x->set_no_bar(level, nx);
+ purpose = next;
+ }
+ --level;
+ }
+ delete purpose;
+ --count_;
+}
+
+template <typename T, typename P>
+inline bool SkipList<T, P>::search(const T& key, P& value)
+{
+ SkipNode* x = find_node(key);
+ if (x && x->key_ == key) {
+ value = x->value_;
+ return true;
+ }
+ return false;
+}
+
+#endif
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..b9fb27c
--- /dev/null
+++ b/README.md
@@ -0,0 +1,17 @@
+# MSkipList
+
+一个根据LevelDb源码修改的直接可用的跳表，纯C++11标准库，跨平台。
+
+# 压力测试
+
+参考[Skiplist-CPP](https://github.com/youngyangyang04/Skiplist-CPP)的压力测试代码：
+
+测得在 Visual Studio 2022 x64 release环境下（Windows 10 Pro）：
+
+- 随机写（10次均值）：0.05002037，即约20w条/s。
+- 随机读（10次均值）：0.0369919，即约27w条/s。
+
+# 说明
+
+- 非线程安全，使用自行加锁。
+- 仅使用`MSkipList.hpp`即可。
diff --git a/main.cpp b/main.cpp
new file mode 100644
index 0000000..cd2c73e
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,36 @@
+#include <iostream>
+#include "MSkipList.hpp"
+
+int main() {
+
+ // 基本使用
+ SkipList<int, std::string> skip;
+ std::string tmp;
+
+ skip.insert(101, "医用外科口罩");
+ skip.insert(98, "C++标准库");
+ skip.insert(12, "Hello World.");
+
+ std::cout << "skip 元素个数：" << skip.count() << "\n";
+ if (skip.search(12, tmp)) {
+ std::cout << "12: " << tmp << "\n";
+ }
+
+ if (skip.search(98, tmp)) {
+ std::cout << "98: " << tmp << "\n";
+ }
+ skip.remove(98);
+ std::cout << "skip 元素个数：" << skip.count() << "\n";
+ if (!skip.search(98, tmp)) {
+ std::cout << "98: 未找到\n";
+ }
+
+ // 析构测试
+ auto* pSkip = new SkipList<int, std::string>(12);
+ pSkip->insert(101, "医用外科口罩");
+ pSkip->insert(98, "C++标准库");
+ pSkip->insert(12, "Hello World.");
+ delete pSkip;
+
+ return 0;
+}
diff --git a/stress.cpp b/stress.cpp
new file mode 100644
index 0000000..f2c4229
--- /dev/null
+++ b/stress.cpp
@@ -0,0 +1,75 @@
+#include <iostream>
+#include <thread>
+#include <chrono>
+#include <string>
+#include <mutex>
+#include <random>
+#include <climits>
+
+#include "MSkipList.hpp"
+
+#define THREAD_COUNT 1
+#define TEST_COUNT 100000
+
+std::random_device g_rd{};
+std::mt19937 g_gen(g_rd());
+std::uniform_int_distribution<int> g_dis(0, std::numeric_limits<int>::max());
+
+std::mutex g_mutex{};
+SkipList<int, std::string> skip(18);
+
+void insertFunc()
+{
+ for (int i = 0; i < TEST_COUNT; ++i) {
+ g_mutex.lock();
+ skip.insert(g_dis(g_gen), "Hello World");
+ g_mutex.unlock();
+ }
+}
+
+void searchFunc()
+{
+ std::string tmp{};
+ for (int i = 0; i < TEST_COUNT; ++i) {
+ g_mutex.lock();
+ skip.search(g_dis(g_gen), tmp);
+ g_mutex.unlock();
+ }
+}
+
+void insertTime()
+{
+ std::thread thread_insert[THREAD_COUNT];
+ auto start = std::chrono::high_resolution_clock::now();
+ for (int i = 0; i < THREAD_COUNT; ++i) {
+ thread_insert[i] = std::thread(insertFunc);
+ }
+ for (int i = 0; i < THREAD_COUNT; ++i) {
+ thread_insert[i].join();
+ }
+ auto finish = std::chrono::high_resolution_clock::now();
+ std::chrono::duration<double> elapsed = finish - start;
+ std::cout << "insert elapsed:" << elapsed.count() << std::endl;
+}
+
+void getTime()
+{
+ std::thread thread_search[THREAD_COUNT];
+ auto start = std::chrono::high_resolution_clock::now();
+ for (int i = 0; i < THREAD_COUNT; ++i) {
+ thread_search[i] = std::thread(searchFunc);
+ }
+ for (int i = 0; i < THREAD_COUNT; ++i) {
+ thread_search[i].join();
+ }
+ auto finish = std::chrono::high_resolution_clock::now();
+ std::chrono::duration<double> elapsed = finish - start;
+ std::cout << "get elapsed:" << elapsed.count() << std::endl;
+}
+
+int main()
+{
+ insertTime();
+ getTime();
+ return 0;
+}
\ No newline at end of file