feat(mysql): datafuse-extras/msql-srv -> opensrv-mysql (#3)

Author: Chojan Shang

mysql/Cargo.toml

@@ -1,8 +1,27 @@
 [package]
-name = "mysql"
+name = "opensrv-mysql"
 version = "0.1.0"
+authors = ["Databend Authors <[email protected]>"]
 edition = "2021"
+license = "Apache-2.0"
+description = "Bindings for emulating a MySQL/MariaDB server."
+readme = "README.md"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[lib]
+doctest = false
+test = false
 
 [dependencies]
+async-trait = "0.1.52"
+byteorder = "1.4.3"
+chrono = "0.4.19"
+mysql_common = { version = "0.28.0", features = ["chrono"] }
+nom = "7.1.0"
+tokio = { version = "1.17.0", features = ["io-util", "io-std"] }
+
+[dev-dependencies]
+mysql = "22.0.0"
+postgres = "0.19.2"
+slab = "0.4.2"
+mysql_async = "0.29.0"
+tokio = { version = "1.0", features = ["full"] }

mysql/README.md

@@ -0,0 +1,62 @@
+# OpenSrv - MySQL
+
+Bindings for emulating a MySQL/MariaDB server.
+
+When developing new databases or caching layers, it can be immensely useful to test your system
+using existing applications. However, this often requires significant work modifying
+applications to use your database over the existing ones. This crate solves that problem by
+acting as a MySQL server, and delegating operations such as querying and query execution to
+user-defined logic.
+
+To start, implement `MysqlShim/AsyncMysqlShim` for your backend, and create a `MysqlIntermediary/AsyncMysqlIntermediary` over an
+instance of your backend and a connection stream. The appropriate methods will be called on
+your backend whenever a client issues a `QUERY`, `PREPARE`, or `EXECUTE` command, and you will
+have a chance to respond appropriately. For example, to write a shim that always responds to
+all commands with a "no results" reply:
+
+```rust
+use std::io;
+use std::net;
+use std::thread;
+
+use opensrv_mysql::*;
+
+struct Backend;
+
+impl<W: io::Write> MysqlShim<W> for Backend {
+    type Error = io::Error;
+
+    fn on_prepare(&mut self, _: &str, info: StatementMetaWriter<W>) -> io::Result<()> {
+        info.reply(42, &[], &[])
+    }
+    fn on_execute(
+        &mut self,
+        _: u32,
+        _: opensrv_mysql::ParamParser,
+        results: QueryResultWriter<W>,
+    ) -> io::Result<()> {
+        results.completed(OkResponse::default())
+    }
+    fn on_close(&mut self, _: u32) {}
+
+    fn on_query(&mut self, sql: &str, results: QueryResultWriter<W>) -> io::Result<()> {
+        println!("execute sql {:?}", sql);
+        results.start(&[])?.finish()
+    }
+}
+
+fn main() {
+    let mut threads = Vec::new();
+    let listener = net::TcpListener::bind("127.0.0.1:3306").unwrap();
+
+    while let Ok((s, _)) = listener.accept() {
+        threads.push(thread::spawn(move || {
+            MysqlIntermediary::run_on_tcp(Backend, s).unwrap();
+        }));
+    }
+
+    for t in threads {
+        t.join().unwrap();
+    }
+}
+```