build the progem about rust database

.gitignore

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+/target

Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "rustdb"
+version = "0.1.0"

Cargo.toml

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+[package]
+name = "rustdb"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

src/algorithm/mod.rs

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+pub mod random;

src/algorithm/random.rs

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+///# random
+/// <p>Random algorithm is very important for this database,because if we insert data into skiplist the random algorithm
+/// will help us to select the level of the node.However if we use  incorrect random algorithm the skiplist will become a Linklist,
+/// and if we want to search a data,we will waste $$ O(n^2)$$ times.</p>
+
+#[allow(unused)]
+pub mod random{
+    ///
+    /// ## LGC 
+    ///$$
+    /// x_0=SEED
+    /// $$
+    /// $$
+    /// X_n=(A \times X_(n-1) + C)%M
+    /// $$
+    /// 
+    static mut SEED:usize=1;                    //全局静态变量用于保存数据
+    static A:usize=1103515245;
+    static C:usize=12345;
+    
+    pub fn lgc(_level:usize)->usize{                        //线性混合同余法求解随机数
+    unsafe {
+        SEED=(SEED*A+C)%_level;
+        SEED
+        }
+    }
+
+    pub fn lgc_withseed(_seed:usize,_level:usize)->usize
+    {
+        unsafe {
+            SEED=(_seed*A+C)%_level;
+            SEED
+            }       
+    }
+
+
+
+
+}

src/basic_structure/mod.rs

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+pub mod skiplist;

src/basic_structure/skiplist.rs

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+///# Skiplist
+///<p>skiplist is an important data structure of database and many database use this as the basic structure in memory.
+/// In the database I also use two Skiplist in memory to store datas temperary.</p>
+
+use crate::algorithm;
+pub mod skip_lists
+{
+    use std::{cell::RefCell, rc::Rc};
+
+    use crate::algorithm::random;
+
+    #[derive(Debug,Clone)]
+    ///## Node of skiplist
+    ///
+    /// <p>We will build a kv database,so the node has two members key and value.</p>
+    ///
+    /// <p>The node would never be used out of the mod.</p>
+    struct Node<K,V>                              
+    {
+        key:K,
+        value:V,
+        level:usize,
+        forward:Vec<Option<Rc<RefCell<Node<K,V>>>>>
+    }
+    impl<K,V> Node<K,V>{
+        fn new(_key:K,_value:V,_level:usize)->Rc<RefCell<Self>>
+        {
+            Rc::new(
+                RefCell::new(
+                    Node
+                    {
+                        key:_key,
+                        value:_value,
+                        level:_level,
+                        forward:vec![None;_level+1]
+                    }
+                )
+            )
+        }
+    }
+    
+    
+    ///## Skiplist
+    /// 
+    /// 
+    #[derive(Debug)]
+    pub struct Skiplists<K,V>
+    {
+        max_level:usize,
+        current_level:usize,
+        current_size:usize,
+        head:Vec<Option<Rc<RefCell<Node<K,V>>>>>
+    }
+
+    impl<K,V> Skiplists<K,V>
+    {
+        pub fn new(_max_size:usize)->Self
+        {
+            
+            Skiplists
+            {
+                max_level:_max_size,
+                current_level:0,
+                current_size:0,
+                head:vec![None;_max_size+1]
+
+            }
+        }
+
+        fn creat_node(_key:K,_value:V,_level:usize)->Rc<RefCell<Node<K,V>>>
+        {
+            Node::new(_key, _value, _level)
+        }
+
+        fn insert(&mut self,_key:K,_value:V)->bool
+        {
+            let mut update:Vec<Option<Rc<RefCell<Node<K,V>>>>>=vec![None;self.current_level];
+            let mut _node_level=random::random::lgc(self.max_level);
+            let new_node: Rc<RefCell<Node<K, V>>>=Node::<K,V>::new(_key, _value, _node_level);
+            if self.current_size==0
+            {
+                let mut begin:usize=0;
+                
+                while(begin<=_node_level)
+                {
+                    self.head[begin]=Some(new_node.clone());             //if the skiplist is empty,insert directly.
+                    begin=begin+1;
+                }
+                
+            }
+            else {
+                let mut tmp:usize=_node_level;                     //search the correct place up to down
+                
+            }
+            true
+        }
+    }
+}

src/main.rs

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+mod basic_structure;
+mod algorithm;
+fn main() {
+    let  data: basic_structure::skiplist::skip_lists::Skiplists<i32, i32>=basic_structure::skiplist::skip_lists::Skiplists::<i32,i32>::new(1);
+    println!("Hello, world!");
+}