提取为库

Readme.md

@@ -1,13 +1,22 @@
 ## 软件介绍
-这是一个解析sql语句中的注释，具备一下两个能力：
-- 提取sql中的注释（开发中）
-- 移除sql中的注释（已完成）
+> 移植于：
+> https://github.com/wangjie-fourth/SqlParser/blob/main/src/main/java/myself/SqlCommentParser.java
+
+解析sql语句中的注释，具备以下两个能力：
+- 提取sql中的注释（✅）
+- 移除sql中的注释（✅）
 ## 快速使用
 ```rust
-let sql = "SELECT * FROM table--; -- This is a single line comment";
-let mut parser = SqlCommentParser::new(&sql);
-let cleaned_sql = parser.remove_comment_sql();
-println!("{}", cleaned_sql);
+use sql_comment_parser::SqlCommentParser;
+
+fn main() {
+    let sql = "SELECT * FROM table--; -- This is a single line comment";
+    let mut parser = SqlCommentParser::new(&sql);
+    let comment_sql = parser.get_comment_sql();
+    let cleaned_sql = parser.remove_comment_sql();
+    println!("{}", cleaned_sql); //打印SELECT * FROM table
+    println!("{}", comment_sql); //打印--; -- This is a single line comment
+}
 ```
 ## 参考链接
-https://github.com/wangjie-fourth/SqlParser/blob/main/src/main/java/myself/SqlCommentParser.java
+https://wangjie-fourth.github.io/2021/01/30/experience/remove-comment-in-sql/

src/lib.rs

@@ -0,0 +1,193 @@
+#[derive(Debug)]
+pub struct SqlCommentParser<'a> {
+    sql: &'a str,
+    pos: usize,
+    start: usize,
+}
+
+#[derive(Debug)]
+struct Comment {
+    start_index: usize,
+    end_index: usize,
+}
+
+impl Comment {
+    fn new(start: usize, end: usize) -> Self {
+        Self {
+            start_index: start,
+            end_index: end,
+        }
+    }
+}
+
+impl<'a> SqlCommentParser<'a> {
+    pub fn new(sql: &'a str) -> Self {
+        Self {
+            sql,
+            pos: 0,
+            start: 0,
+        }
+    }
+
+    pub fn get_comment_sql(&mut self) -> String {
+        let mut comment_sql = String::new();
+        loop {
+            match self.next_comment() {
+                Some(comment_range) => {
+                    comment_sql
+                        .push_str(&self.sql[comment_range.start_index..comment_range.end_index]);
+                }
+                None => {
+                    break;
+                }
+            };
+        }
+        comment_sql
+    }
+
+    pub fn remove_comment_sql(&mut self) -> String {
+        let mut new_sql = String::new();
+        let mut start_index = 0;
+        loop {
+            match self.next_comment() {
+                Some(comment_range) => {
+                    new_sql.push_str(&self.sql[start_index..comment_range.start_index]);
+                    start_index = comment_range.end_index;
+                }
+                None => {
+                    if start_index != self.sql.len() {
+                        new_sql.push_str(&self.sql[start_index..]);
+                    }
+                    break;
+                }
+            };
+        }
+        new_sql
+    }
+
+    fn next_comment(&mut self) -> Option<Comment> {
+        while self.pos < self.sql.len() {
+            let c = self.sql.as_bytes()[self.pos] as char;
+            let start_index;
+            match c {
+                '\'' => {
+                    self.start = self.pos;
+                    self.pos += 1;
+                    while self.pos < self.sql.len() {
+                        let c = self.sql.as_bytes()[self.pos] as char;
+                        self.pos += 1;
+                        if c == '\'' {
+                            break;
+                        }
+                    }
+                }
+                '`' => {
+                    self.start = self.pos;
+                    self.pos += 1;
+                    while self.pos < self.sql.len() {
+                        let c = self.sql.as_bytes()[self.pos] as char;
+                        self.pos += 1;
+                        if c == '`' {
+                            break;
+                        }
+                    }
+                }
+                '\"' => {
+                    self.start = self.pos;
+                    self.pos += 1;
+                    while self.pos < self.sql.len() {
+                        let c = self.sql.as_bytes()[self.pos] as char;
+                        self.pos += 1;
+                        if c == '\"' {
+                            break;
+                        }
+                    }
+                }
+                '/' => {
+                    // possible start of '/*'
+                    if self.pos + 1 < self.sql.len() {
+                        let c = self.sql.as_bytes()[self.pos + 1] as char;
+                        if c == '*' {
+                            start_index = self.pos;
+                            // 从pos + 2开始查找"*/"
+                            let end: usize = match self.sql.find("*/") {
+                                Some(end) => end + "*/".len(),
+                                None => self.sql.len(),
+                            };
+
+                            // 更新pos并计算end_index
+                            self.pos = end;
+                            let end_index = self.pos;
+
+                            return Some(Comment::new(start_index, end_index));
+                        }
+                    }
+                }
+                '-' => {
+                    // possible start of '--' comment
+                    if c == '-'
+                        && self.pos + 1 < self.sql.len()
+                        && self.sql.as_bytes()[self.pos + 1] as char == '-'
+                    {
+                        start_index = self.pos;
+                        self.pos = SqlCommentParser::index_of_line_end(self.sql, self.pos + 2);
+                        let end_index = self.pos;
+                        return Some(Comment::new(start_index, end_index));
+                    }
+                }
+                _ => {
+                    if SqlCommentParser::is_open_quote(c) {
+                        break;
+                    } else {
+                        loop {
+                            self.pos += 1;
+                            if self.pos >= self.sql.len() {
+                                break;
+                            }
+                            let c = self.sql.as_bytes()[self.pos] as char;
+                            match c {
+                                '\'' | '`' | '\"' | '/' => break,
+                                '-' => {
+                                    if self.pos + 1 < self.sql.len()
+                                        && self.sql.as_bytes()[self.pos + 1] as char == '-'
+                                    {
+                                        break;
+                                    }
+                                }
+                                _ => {}
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        return None;
+    }
+
+    fn index_of_line_end(sql: &'a str, mut i: usize) -> usize {
+        let length = sql.len();
+        while i < length {
+            let c = sql.as_bytes()[i] as char;
+            match c {
+                '\r' | '\n' => {
+                    return i;
+                }
+                _ => {
+                    i += 1;
+                }
+            }
+        }
+        return i;
+    }
+
+    fn is_open_quote(character: char) -> bool {
+        match character {
+            '\"' | '`' | '\'' => {
+                return true;
+            }
+            _ => {
+                return false;
+            }
+        }
+    }
+}