tmp2

Signed-off-by: junxiang Mu <1948535941@qq.com>

s3select/query/src/sql/parser.rs

@@ -0,0 +1,97 @@
+use std::{collections::VecDeque, fmt::Display};
+
+use api::{
+    query::{ast::ExtStatement, parser::Parser as RustFsParser},
+    ParserSnafu,
+};
+use datafusion::sql::sqlparser::{
+    dialect::Dialect,
+    parser::{Parser, ParserError},
+    tokenizer::{Token, Tokenizer},
+};
+use snafu::ResultExt;
+
+use super::dialect::RustFsDialect;
+
+pub type Result<T, E = ParserError> = std::result::Result<T, E>;
+
+// Use `Parser::expected` instead, if possible
+macro_rules! parser_err {
+    ($MSG:expr) => {
+        Err(ParserError::ParserError($MSG.to_string()))
+    };
+}
+
+#[derive(Default)]
+pub struct DefaultParser {}
+
+impl RustFsParser for DefaultParser {
+    fn parse(&self, sql: &str) -> api::QueryResult<VecDeque<ExtStatement>> {
+        ExtParser::parse_sql(sql).context(ParserSnafu)
+    }
+}
+
+/// SQL Parser
+pub struct ExtParser<'a> {
+    parser: Parser<'a>,
+}
+
+impl<'a> ExtParser<'a> {
+    /// Parse the specified tokens with dialect
+    fn new_with_dialect(sql: &str, dialect: &'a dyn Dialect) -> Result<Self> {
+        let mut tokenizer = Tokenizer::new(dialect, sql);
+        let tokens = tokenizer.tokenize()?;
+        Ok(ExtParser {
+            parser: Parser::new(dialect).with_tokens(tokens),
+        })
+    }
+
+    /// Parse a SQL statement and produce a set of statements
+    pub fn parse_sql(sql: &str) -> Result<VecDeque<ExtStatement>> {
+        let dialect = &RustFsDialect {};
+        ExtParser::parse_sql_with_dialect(sql, dialect)
+    }
+
+    /// Parse a SQL statement and produce a set of statements
+    pub fn parse_sql_with_dialect(sql: &str, dialect: &dyn Dialect) -> Result<VecDeque<ExtStatement>> {
+        let mut parser = ExtParser::new_with_dialect(sql, dialect)?;
+        let mut stmts = VecDeque::new();
+        let mut expecting_statement_delimiter = false;
+        loop {
+            // ignore empty statements (between successive statement delimiters)
+            while parser.parser.consume_token(&Token::SemiColon) {
+                expecting_statement_delimiter = false;
+            }
+
+            if parser.parser.peek_token() == Token::EOF {
+                break;
+            }
+            if expecting_statement_delimiter {
+                return parser.expected("end of statement", parser.parser.peek_token());
+            }
+
+            let statement = parser.parse_statement()?;
+            stmts.push_back(statement);
+            expecting_statement_delimiter = true;
+        }
+
+        // debug!("Parser sql: {}, stmts: {:#?}", sql, stmts);
+
+        Ok(stmts)
+    }
+
+    /// Parse a new expression
+    fn parse_statement(&mut self) -> Result<ExtStatement> {
+        match self.parser.peek_token().token {
+            Token::Word(w) => match w.keyword {
+                _ => Ok(ExtStatement::SqlStatement(Box::new(self.parser.parse_statement()?))),
+            },
+            _ => Ok(ExtStatement::SqlStatement(Box::new(self.parser.parse_statement()?))),
+        }
+    }
+
+    // Report unexpected token
+    fn expected<T>(&self, expected: &str, found: impl Display) -> Result<T> {
+        parser_err!(format!("Expected {}, found: {}", expected, found))
+    }
+}