|
| 1 | +use std::sync::{Arc, Mutex}; |
| 2 | + |
| 3 | +use arrow_pg::datatypes::arrow_schema_to_pg_fields; |
| 4 | +use arrow_pg::datatypes::encode_recordbatch; |
| 5 | +use arrow_pg::datatypes::into_pg_type; |
| 6 | +use async_trait::async_trait; |
| 7 | +use duckdb::{params, Connection, Statement, ToSql}; |
| 8 | +use futures::stream; |
| 9 | +use pgwire::api::auth::md5pass::{hash_md5_password, Md5PasswordAuthStartupHandler}; |
| 10 | +use pgwire::api::auth::{ |
| 11 | + AuthSource, DefaultServerParameterProvider, LoginInfo, Password, StartupHandler, |
| 12 | +}; |
| 13 | +use pgwire::api::portal::{Format, Portal}; |
| 14 | +use pgwire::api::query::{ExtendedQueryHandler, SimpleQueryHandler}; |
| 15 | +use pgwire::api::results::{ |
| 16 | + DescribePortalResponse, DescribeStatementResponse, FieldInfo, QueryResponse, Response, Tag, |
| 17 | +}; |
| 18 | +use pgwire::api::stmt::{NoopQueryParser, StoredStatement}; |
| 19 | +use pgwire::api::{ClientInfo, PgWireServerHandlers, Type}; |
| 20 | +use pgwire::error::{PgWireError, PgWireResult}; |
| 21 | +use pgwire::tokio::process_socket; |
| 22 | +use tokio::net::TcpListener; |
| 23 | + |
| 24 | +pub struct DuckDBBackend { |
| 25 | + conn: Arc<Mutex<Connection>>, |
| 26 | + query_parser: Arc<NoopQueryParser>, |
| 27 | +} |
| 28 | + |
| 29 | +#[derive(Debug)] |
| 30 | +struct DummyAuthSource; |
| 31 | + |
| 32 | +#[async_trait] |
| 33 | +impl AuthSource for DummyAuthSource { |
| 34 | + async fn get_password(&self, login_info: &LoginInfo) -> PgWireResult<Password> { |
| 35 | + println!("login info: {:?}", login_info); |
| 36 | + |
| 37 | + let salt = vec![0, 0, 0, 0]; |
| 38 | + let password = "pencil"; |
| 39 | + |
| 40 | + let hash_password = |
| 41 | + hash_md5_password(login_info.user().as_ref().unwrap(), password, salt.as_ref()); |
| 42 | + Ok(Password::new(Some(salt), hash_password.as_bytes().to_vec())) |
| 43 | + } |
| 44 | +} |
| 45 | + |
| 46 | +#[async_trait] |
| 47 | +impl SimpleQueryHandler for DuckDBBackend { |
| 48 | + async fn do_query<C>(&self, _client: &mut C, query: &str) -> PgWireResult<Vec<Response>> |
| 49 | + where |
| 50 | + C: ClientInfo + Unpin + Send + Sync, |
| 51 | + { |
| 52 | + let conn = self.conn.lock().unwrap(); |
| 53 | + if query.to_uppercase().starts_with("SELECT") { |
| 54 | + let mut stmt = conn |
| 55 | + .prepare(query) |
| 56 | + .map_err(|e| PgWireError::ApiError(Box::new(e)))?; |
| 57 | + |
| 58 | + let ret = stmt |
| 59 | + .query_arrow(params![]) |
| 60 | + .map_err(|e| PgWireError::ApiError(Box::new(e)))?; |
| 61 | + let schema = ret.get_schema(); |
| 62 | + let header = Arc::new(arrow_schema_to_pg_fields( |
| 63 | + schema.as_ref(), |
| 64 | + &Format::UnifiedText, |
| 65 | + )?); |
| 66 | + |
| 67 | + let header_ref = header.clone(); |
| 68 | + let data = ret |
| 69 | + .flat_map(move |rb| encode_recordbatch(header_ref.clone(), rb)) |
| 70 | + .collect::<Vec<_>>(); |
| 71 | + Ok(vec![Response::Query(QueryResponse::new( |
| 72 | + header, |
| 73 | + stream::iter(data.into_iter()), |
| 74 | + ))]) |
| 75 | + } else { |
| 76 | + conn.execute(query, params![]) |
| 77 | + .map(|affected_rows| { |
| 78 | + vec![Response::Execution(Tag::new("OK").with_rows(affected_rows))] |
| 79 | + }) |
| 80 | + .map_err(|e| PgWireError::ApiError(Box::new(e))) |
| 81 | + } |
| 82 | + } |
| 83 | +} |
| 84 | + |
| 85 | +fn get_params(portal: &Portal<String>) -> Vec<Box<dyn ToSql>> { |
| 86 | + let mut results = Vec::with_capacity(portal.parameter_len()); |
| 87 | + for i in 0..portal.parameter_len() { |
| 88 | + let param_type = portal.statement.parameter_types.get(i).unwrap(); |
| 89 | + // we only support a small amount of types for demo |
| 90 | + match param_type { |
| 91 | + &Type::BOOL => { |
| 92 | + let param = portal.parameter::<bool>(i, param_type).unwrap(); |
| 93 | + results.push(Box::new(param) as Box<dyn ToSql>); |
| 94 | + } |
| 95 | + &Type::INT2 => { |
| 96 | + let param = portal.parameter::<i16>(i, param_type).unwrap(); |
| 97 | + results.push(Box::new(param) as Box<dyn ToSql>); |
| 98 | + } |
| 99 | + &Type::INT4 => { |
| 100 | + let param = portal.parameter::<i32>(i, param_type).unwrap(); |
| 101 | + results.push(Box::new(param) as Box<dyn ToSql>); |
| 102 | + } |
| 103 | + &Type::INT8 => { |
| 104 | + let param = portal.parameter::<i64>(i, param_type).unwrap(); |
| 105 | + results.push(Box::new(param) as Box<dyn ToSql>); |
| 106 | + } |
| 107 | + &Type::TEXT | &Type::VARCHAR => { |
| 108 | + let param = portal.parameter::<String>(i, param_type).unwrap(); |
| 109 | + results.push(Box::new(param) as Box<dyn ToSql>); |
| 110 | + } |
| 111 | + &Type::FLOAT4 => { |
| 112 | + let param = portal.parameter::<f32>(i, param_type).unwrap(); |
| 113 | + results.push(Box::new(param) as Box<dyn ToSql>); |
| 114 | + } |
| 115 | + &Type::FLOAT8 => { |
| 116 | + let param = portal.parameter::<f64>(i, param_type).unwrap(); |
| 117 | + results.push(Box::new(param) as Box<dyn ToSql>); |
| 118 | + } |
| 119 | + _ => { |
| 120 | + unimplemented!("parameter type not supported") |
| 121 | + } |
| 122 | + } |
| 123 | + } |
| 124 | + |
| 125 | + results |
| 126 | +} |
| 127 | + |
| 128 | +fn row_desc_from_stmt(stmt: &Statement, format: &Format) -> PgWireResult<Vec<FieldInfo>> { |
| 129 | + let columns = stmt.column_count(); |
| 130 | + |
| 131 | + (0..columns) |
| 132 | + .map(|idx| { |
| 133 | + let datatype = stmt.column_type(idx); |
| 134 | + let name = stmt.column_name(idx).unwrap(); |
| 135 | + |
| 136 | + Ok(FieldInfo::new( |
| 137 | + name.clone(), |
| 138 | + None, |
| 139 | + None, |
| 140 | + into_pg_type(&datatype).unwrap(), |
| 141 | + format.format_for(idx), |
| 142 | + )) |
| 143 | + }) |
| 144 | + .collect() |
| 145 | +} |
| 146 | + |
| 147 | +#[async_trait] |
| 148 | +impl ExtendedQueryHandler for DuckDBBackend { |
| 149 | + type Statement = String; |
| 150 | + type QueryParser = NoopQueryParser; |
| 151 | + |
| 152 | + fn query_parser(&self) -> Arc<Self::QueryParser> { |
| 153 | + self.query_parser.clone() |
| 154 | + } |
| 155 | + |
| 156 | + async fn do_query<C>( |
| 157 | + &self, |
| 158 | + _client: &mut C, |
| 159 | + portal: &Portal<Self::Statement>, |
| 160 | + _max_rows: usize, |
| 161 | + ) -> PgWireResult<Response> |
| 162 | + where |
| 163 | + C: ClientInfo + Unpin + Send + Sync, |
| 164 | + { |
| 165 | + let conn = self.conn.lock().unwrap(); |
| 166 | + let query = &portal.statement.statement; |
| 167 | + let mut stmt = conn |
| 168 | + .prepare_cached(query) |
| 169 | + .map_err(|e| PgWireError::ApiError(Box::new(e)))?; |
| 170 | + let params = get_params(portal); |
| 171 | + let params_ref = params |
| 172 | + .iter() |
| 173 | + .map(|f| f.as_ref()) |
| 174 | + .collect::<Vec<&dyn duckdb::ToSql>>(); |
| 175 | + |
| 176 | + if query.to_uppercase().starts_with("SELECT") { |
| 177 | + let ret = stmt |
| 178 | + .query_arrow(params![]) |
| 179 | + .map_err(|e| PgWireError::ApiError(Box::new(e)))?; |
| 180 | + let schema = ret.get_schema(); |
| 181 | + let header = Arc::new(arrow_schema_to_pg_fields( |
| 182 | + schema.as_ref(), |
| 183 | + &Format::UnifiedText, |
| 184 | + )?); |
| 185 | + |
| 186 | + let header_ref = header.clone(); |
| 187 | + let data = ret |
| 188 | + .flat_map(move |rb| encode_recordbatch(header_ref.clone(), rb)) |
| 189 | + .collect::<Vec<_>>(); |
| 190 | + |
| 191 | + Ok(Response::Query(QueryResponse::new( |
| 192 | + header, |
| 193 | + stream::iter(data.into_iter()), |
| 194 | + ))) |
| 195 | + } else { |
| 196 | + stmt.execute::<&[&dyn duckdb::ToSql]>(params_ref.as_ref()) |
| 197 | + .map(|affected_rows| Response::Execution(Tag::new("OK").with_rows(affected_rows))) |
| 198 | + .map_err(|e| PgWireError::ApiError(Box::new(e))) |
| 199 | + } |
| 200 | + } |
| 201 | + |
| 202 | + async fn do_describe_statement<C>( |
| 203 | + &self, |
| 204 | + _client: &mut C, |
| 205 | + stmt: &StoredStatement<Self::Statement>, |
| 206 | + ) -> PgWireResult<DescribeStatementResponse> |
| 207 | + where |
| 208 | + C: ClientInfo + Unpin + Send + Sync, |
| 209 | + { |
| 210 | + let conn = self.conn.lock().unwrap(); |
| 211 | + let param_types = stmt.parameter_types.clone(); |
| 212 | + let stmt = conn |
| 213 | + .prepare_cached(&stmt.statement) |
| 214 | + .map_err(|e| PgWireError::ApiError(Box::new(e)))?; |
| 215 | + row_desc_from_stmt(&stmt, &Format::UnifiedBinary) |
| 216 | + .map(|fields| DescribeStatementResponse::new(param_types, fields)) |
| 217 | + } |
| 218 | + |
| 219 | + async fn do_describe_portal<C>( |
| 220 | + &self, |
| 221 | + _client: &mut C, |
| 222 | + portal: &Portal<Self::Statement>, |
| 223 | + ) -> PgWireResult<DescribePortalResponse> |
| 224 | + where |
| 225 | + C: ClientInfo + Unpin + Send + Sync, |
| 226 | + { |
| 227 | + let conn = self.conn.lock().unwrap(); |
| 228 | + let stmt = conn |
| 229 | + .prepare_cached(&portal.statement.statement) |
| 230 | + .map_err(|e| PgWireError::ApiError(Box::new(e)))?; |
| 231 | + row_desc_from_stmt(&stmt, &portal.result_column_format).map(DescribePortalResponse::new) |
| 232 | + } |
| 233 | +} |
| 234 | + |
| 235 | +impl DuckDBBackend { |
| 236 | + fn new() -> DuckDBBackend { |
| 237 | + DuckDBBackend { |
| 238 | + conn: Arc::new(Mutex::new(Connection::open_in_memory().unwrap())), |
| 239 | + query_parser: Arc::new(NoopQueryParser::new()), |
| 240 | + } |
| 241 | + } |
| 242 | +} |
| 243 | + |
| 244 | +struct DuckDBBackendFactory { |
| 245 | + handler: Arc<DuckDBBackend>, |
| 246 | +} |
| 247 | + |
| 248 | +impl PgWireServerHandlers for DuckDBBackendFactory { |
| 249 | + fn simple_query_handler(&self) -> Arc<impl SimpleQueryHandler> { |
| 250 | + self.handler.clone() |
| 251 | + } |
| 252 | + |
| 253 | + fn extended_query_handler(&self) -> Arc<impl ExtendedQueryHandler> { |
| 254 | + self.handler.clone() |
| 255 | + } |
| 256 | + |
| 257 | + fn startup_handler(&self) -> Arc<impl StartupHandler> { |
| 258 | + Arc::new(Md5PasswordAuthStartupHandler::new( |
| 259 | + Arc::new(DummyAuthSource), |
| 260 | + Arc::new(DefaultServerParameterProvider::default()), |
| 261 | + )) |
| 262 | + } |
| 263 | +} |
| 264 | + |
| 265 | +#[tokio::main] |
| 266 | +pub async fn main() { |
| 267 | + let factory = Arc::new(DuckDBBackendFactory { |
| 268 | + handler: Arc::new(DuckDBBackend::new()), |
| 269 | + }); |
| 270 | + let server_addr = "127.0.0.1:5432"; |
| 271 | + let listener = TcpListener::bind(server_addr).await.unwrap(); |
| 272 | + println!( |
| 273 | + "Listening to {}, use password `pencil` to connect", |
| 274 | + server_addr |
| 275 | + ); |
| 276 | + loop { |
| 277 | + let incoming_socket = listener.accept().await.unwrap(); |
| 278 | + let factory_ref = factory.clone(); |
| 279 | + |
| 280 | + tokio::spawn(async move { process_socket(incoming_socket.0, None, factory_ref).await }); |
| 281 | + } |
| 282 | +} |
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