pgwire/
pg_response.rs

1// Copyright 2025 RisingWave Labs
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use std::fmt::Formatter;
16use std::pin::Pin;
17
18use futures::{Future, FutureExt, Stream, StreamExt};
19use risingwave_sqlparser::ast::Statement;
20
21use crate::error::PsqlError;
22use crate::pg_field_descriptor::PgFieldDescriptor;
23use crate::pg_protocol::ParameterStatus;
24use crate::pg_server::BoxedError;
25use crate::types::{Format, Row};
26
27pub type RowSet = Vec<Row>;
28pub type RowSetResult = Result<RowSet, BoxedError>;
29
30pub trait ValuesStream = Stream<Item = RowSetResult> + Unpin + Send;
31
32#[derive(Copy, Clone, Debug, Eq, PartialEq)]
33#[expect(non_camel_case_types, clippy::upper_case_acronyms)]
34pub enum StatementType {
35    INSERT,
36    INSERT_RETURNING,
37    DELETE,
38    DELETE_RETURNING,
39    UPDATE,
40    UPDATE_RETURNING,
41    SELECT,
42    MOVE,
43    FETCH,
44    COPY,
45    EXPLAIN,
46    CLOSE_CURSOR,
47    CREATE_TABLE,
48    CREATE_MATERIALIZED_VIEW,
49    CREATE_VIEW,
50    CREATE_SOURCE,
51    CREATE_SINK,
52    CREATE_SUBSCRIPTION,
53    CREATE_DATABASE,
54    CREATE_SCHEMA,
55    CREATE_USER,
56    CREATE_INDEX,
57    CREATE_AGGREGATE,
58    CREATE_FUNCTION,
59    CREATE_CONNECTION,
60    CREATE_SECRET,
61    COMMENT,
62    DECLARE_CURSOR,
63    DESCRIBE,
64    GRANT_PRIVILEGE,
65    DISCARD,
66    DROP_TABLE,
67    DROP_MATERIALIZED_VIEW,
68    DROP_VIEW,
69    DROP_INDEX,
70    DROP_FUNCTION,
71    DROP_AGGREGATE,
72    DROP_SOURCE,
73    DROP_SINK,
74    DROP_SUBSCRIPTION,
75    DROP_SCHEMA,
76    DROP_DATABASE,
77    DROP_USER,
78    DROP_CONNECTION,
79    DROP_SECRET,
80    ALTER_DATABASE,
81    ALTER_DEFAULT_PRIVILEGES,
82    ALTER_SCHEMA,
83    ALTER_INDEX,
84    ALTER_VIEW,
85    ALTER_TABLE,
86    ALTER_MATERIALIZED_VIEW,
87    ALTER_SINK,
88    ALTER_SUBSCRIPTION,
89    ALTER_SOURCE,
90    ALTER_FUNCTION,
91    ALTER_CONNECTION,
92    ALTER_SYSTEM,
93    ALTER_SECRET,
94    REVOKE_PRIVILEGE,
95    // Introduce ORDER_BY statement type cuz Calcite unvalidated AST has SqlKind.ORDER_BY. Note
96    // that Statement Type is not designed to be one to one mapping with SqlKind.
97    ORDER_BY,
98    SET_VARIABLE,
99    SHOW_VARIABLE,
100    SHOW_COMMAND,
101    START_TRANSACTION,
102    UPDATE_USER,
103    ABORT,
104    FLUSH,
105    REFRESH_TABLE,
106    OTHER,
107    // EMPTY is used when query statement is empty (e.g. ";").
108    EMPTY,
109    BEGIN,
110    COMMIT,
111    ROLLBACK,
112    SET_TRANSACTION,
113    CANCEL_COMMAND,
114    FETCH_CURSOR,
115    WAIT,
116    KILL,
117    RECOVER,
118    USE,
119    PREPARE,
120    DEALLOCATE,
121    VACUUM,
122}
123
124impl std::fmt::Display for StatementType {
125    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
126        write!(f, "{:?}", self)
127    }
128}
129
130pub trait Callback = Future<Output = Result<(), BoxedError>> + Send;
131
132pub type BoxedCallback = Pin<Box<dyn Callback>>;
133
134pub struct PgResponse<VS> {
135    stmt_type: StatementType,
136    is_copy_query_to_stdout: bool,
137
138    // row count of affected row. Used for INSERT, UPDATE, DELETE, COPY, and other statements that
139    // don't return rows.
140    row_cnt: Option<i32>,
141    // Used for INSERT, UPDATE, DELETE to specify the format of the affected row count.
142    row_cnt_format: Option<Format>,
143    notices: Vec<String>,
144    values_stream: Option<VS>,
145    callback: Option<BoxedCallback>,
146    row_desc: Vec<PgFieldDescriptor>,
147    status: ParameterStatus,
148}
149
150pub struct PgResponseBuilder<VS> {
151    stmt_type: StatementType,
152    // row count of affected row. Used for INSERT, UPDATE, DELETE, COPY, and other statements that
153    // don't return rows.
154    row_cnt: Option<i32>,
155    // Used for INSERT, UPDATE, DELETE to specify the format of the affected row count.
156    row_cnt_format: Option<Format>,
157    notices: Vec<String>,
158    values_stream: Option<VS>,
159    callback: Option<BoxedCallback>,
160    row_desc: Vec<PgFieldDescriptor>,
161    status: ParameterStatus,
162}
163
164impl<VS> From<PgResponseBuilder<VS>> for PgResponse<VS> {
165    fn from(builder: PgResponseBuilder<VS>) -> Self {
166        Self {
167            stmt_type: builder.stmt_type,
168            is_copy_query_to_stdout: false, // set a false from builder, alter later
169            row_cnt: builder.row_cnt,
170            row_cnt_format: builder.row_cnt_format,
171            notices: builder.notices,
172            values_stream: builder.values_stream,
173            callback: builder.callback,
174            row_desc: builder.row_desc,
175            status: builder.status,
176        }
177    }
178}
179
180impl<VS> PgResponseBuilder<VS> {
181    pub fn empty(stmt_type: StatementType) -> Self {
182        let row_cnt = if stmt_type.is_query() { None } else { Some(0) };
183        Self {
184            stmt_type,
185            row_cnt,
186            row_cnt_format: None,
187            notices: vec![],
188            values_stream: None,
189            callback: None,
190            row_desc: vec![],
191            status: Default::default(),
192        }
193    }
194
195    pub fn row_cnt(self, row_cnt: i32) -> Self {
196        Self {
197            row_cnt: Some(row_cnt),
198            ..self
199        }
200    }
201
202    pub fn row_cnt_opt(self, row_cnt: Option<i32>) -> Self {
203        Self { row_cnt, ..self }
204    }
205
206    pub fn row_cnt_format_opt(self, row_cnt_format: Option<Format>) -> Self {
207        Self {
208            row_cnt_format,
209            ..self
210        }
211    }
212
213    pub fn values(self, values_stream: VS, row_desc: Vec<PgFieldDescriptor>) -> Self {
214        Self {
215            values_stream: Some(values_stream),
216            row_desc,
217            ..self
218        }
219    }
220
221    pub fn callback(self, callback: impl Callback + 'static) -> Self {
222        Self {
223            callback: Some(callback.boxed()),
224            ..self
225        }
226    }
227
228    pub fn notice(self, notice: impl ToString) -> Self {
229        let mut notices = self.notices;
230        notices.push(notice.to_string());
231        Self { notices, ..self }
232    }
233
234    pub fn status(self, status: ParameterStatus) -> Self {
235        Self { status, ..self }
236    }
237}
238
239impl<VS> std::fmt::Debug for PgResponse<VS> {
240    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
241        f.debug_struct("PgResponse")
242            .field("stmt_type", &self.stmt_type)
243            .field("row_cnt", &self.row_cnt)
244            .field("notices", &self.notices)
245            .field("row_desc", &self.row_desc)
246            .finish()
247    }
248}
249
250impl StatementType {
251    pub fn infer_from_statement(stmt: &Statement) -> Result<Self, String> {
252        match stmt {
253            Statement::Query(_) => Ok(StatementType::SELECT),
254            Statement::Insert { returning, .. } => {
255                if returning.is_empty() {
256                    Ok(StatementType::INSERT)
257                } else {
258                    Ok(StatementType::INSERT_RETURNING)
259                }
260            }
261            Statement::Delete { returning, .. } => {
262                if returning.is_empty() {
263                    Ok(StatementType::DELETE)
264                } else {
265                    Ok(StatementType::DELETE_RETURNING)
266                }
267            }
268            Statement::Update { returning, .. } => {
269                if returning.is_empty() {
270                    Ok(StatementType::UPDATE)
271                } else {
272                    Ok(StatementType::UPDATE_RETURNING)
273                }
274            }
275            Statement::Copy { .. } => Ok(StatementType::COPY),
276            Statement::CreateTable { .. } => Ok(StatementType::CREATE_TABLE),
277            Statement::CreateIndex { .. } => Ok(StatementType::CREATE_INDEX),
278            Statement::CreateSchema { .. } => Ok(StatementType::CREATE_SCHEMA),
279            Statement::CreateSource { .. } => Ok(StatementType::CREATE_SOURCE),
280            Statement::CreateSink { .. } => Ok(StatementType::CREATE_SINK),
281            Statement::CreateFunction { .. } => Ok(StatementType::CREATE_FUNCTION),
282            Statement::CreateDatabase { .. } => Ok(StatementType::CREATE_DATABASE),
283            Statement::CreateUser { .. } => Ok(StatementType::CREATE_USER),
284            Statement::CreateView { materialized, .. } => {
285                if *materialized {
286                    Ok(StatementType::CREATE_MATERIALIZED_VIEW)
287                } else {
288                    Ok(StatementType::CREATE_VIEW)
289                }
290            }
291            Statement::AlterTable { .. } => Ok(StatementType::ALTER_TABLE),
292            Statement::AlterSystem { .. } => Ok(StatementType::ALTER_SYSTEM),
293            Statement::DropFunction { .. } => Ok(StatementType::DROP_FUNCTION),
294            Statement::Discard(..) => Ok(StatementType::DISCARD),
295            Statement::SetVariable { .. } => Ok(StatementType::SET_VARIABLE),
296            Statement::ShowVariable { .. } => Ok(StatementType::SHOW_VARIABLE),
297            Statement::StartTransaction { .. } => Ok(StatementType::START_TRANSACTION),
298            Statement::Begin { .. } => Ok(StatementType::BEGIN),
299            Statement::Abort => Ok(StatementType::ABORT),
300            Statement::Commit { .. } => Ok(StatementType::COMMIT),
301            Statement::Rollback { .. } => Ok(StatementType::ROLLBACK),
302            Statement::Grant { .. } => Ok(StatementType::GRANT_PRIVILEGE),
303            Statement::Revoke { .. } => Ok(StatementType::REVOKE_PRIVILEGE),
304            Statement::Describe { .. } => Ok(StatementType::DESCRIBE),
305            Statement::ShowCreateObject { .. } | Statement::ShowObjects { .. } => {
306                Ok(StatementType::SHOW_COMMAND)
307            }
308            Statement::Drop(stmt) => match stmt.object_type {
309                risingwave_sqlparser::ast::ObjectType::Table => Ok(StatementType::DROP_TABLE),
310                risingwave_sqlparser::ast::ObjectType::View => Ok(StatementType::DROP_VIEW),
311                risingwave_sqlparser::ast::ObjectType::MaterializedView => {
312                    Ok(StatementType::DROP_MATERIALIZED_VIEW)
313                }
314                risingwave_sqlparser::ast::ObjectType::Index => Ok(StatementType::DROP_INDEX),
315                risingwave_sqlparser::ast::ObjectType::Schema => Ok(StatementType::DROP_SCHEMA),
316                risingwave_sqlparser::ast::ObjectType::Source => Ok(StatementType::DROP_SOURCE),
317                risingwave_sqlparser::ast::ObjectType::Sink => Ok(StatementType::DROP_SINK),
318                risingwave_sqlparser::ast::ObjectType::Database => Ok(StatementType::DROP_DATABASE),
319                risingwave_sqlparser::ast::ObjectType::User => Ok(StatementType::DROP_USER),
320                risingwave_sqlparser::ast::ObjectType::Connection => {
321                    Ok(StatementType::DROP_CONNECTION)
322                }
323                risingwave_sqlparser::ast::ObjectType::Secret => Ok(StatementType::DROP_SECRET),
324                risingwave_sqlparser::ast::ObjectType::Subscription => {
325                    Ok(StatementType::DROP_SUBSCRIPTION)
326                }
327            },
328            Statement::Explain { .. } => Ok(StatementType::EXPLAIN),
329            Statement::DeclareCursor { .. } => Ok(StatementType::DECLARE_CURSOR),
330            Statement::FetchCursor { .. } => Ok(StatementType::FETCH_CURSOR),
331            Statement::CloseCursor { .. } => Ok(StatementType::CLOSE_CURSOR),
332            Statement::Flush => Ok(StatementType::FLUSH),
333            Statement::Wait => Ok(StatementType::WAIT),
334            Statement::Use { .. } => Ok(StatementType::USE),
335            Statement::Vacuum { .. } => Ok(StatementType::VACUUM),
336            _ => Err("unsupported statement type".to_owned()),
337        }
338    }
339
340    pub fn is_command(&self) -> bool {
341        matches!(
342            self,
343            StatementType::INSERT
344                | StatementType::DELETE
345                | StatementType::UPDATE
346                | StatementType::MOVE
347                | StatementType::COPY
348                | StatementType::FETCH
349                | StatementType::SELECT
350                | StatementType::INSERT_RETURNING
351                | StatementType::DELETE_RETURNING
352                | StatementType::UPDATE_RETURNING
353        )
354    }
355
356    pub fn is_dml(&self) -> bool {
357        matches!(
358            self,
359            StatementType::INSERT
360                | StatementType::DELETE
361                | StatementType::UPDATE
362                | StatementType::INSERT_RETURNING
363                | StatementType::DELETE_RETURNING
364                | StatementType::UPDATE_RETURNING
365        )
366    }
367
368    pub fn is_query(&self) -> bool {
369        matches!(
370            self,
371            StatementType::SELECT
372                | StatementType::EXPLAIN
373                | StatementType::SHOW_COMMAND
374                | StatementType::SHOW_VARIABLE
375                | StatementType::DESCRIBE
376                | StatementType::INSERT_RETURNING
377                | StatementType::DELETE_RETURNING
378                | StatementType::UPDATE_RETURNING
379                | StatementType::CANCEL_COMMAND
380                | StatementType::FETCH_CURSOR
381        )
382    }
383
384    pub fn is_returning(&self) -> bool {
385        matches!(
386            self,
387            StatementType::INSERT_RETURNING
388                | StatementType::DELETE_RETURNING
389                | StatementType::UPDATE_RETURNING
390        )
391    }
392}
393
394impl<VS> PgResponse<VS>
395where
396    VS: ValuesStream,
397{
398    pub fn builder(stmt_type: StatementType) -> PgResponseBuilder<VS> {
399        PgResponseBuilder::empty(stmt_type)
400    }
401
402    pub fn empty_result(stmt_type: StatementType) -> Self {
403        PgResponseBuilder::empty(stmt_type).into()
404    }
405
406    pub fn into_copy_query_to_stdout(mut self) -> Self {
407        self.is_copy_query_to_stdout = true;
408        self.stmt_type = StatementType::COPY;
409        self
410    }
411
412    pub fn stmt_type(&self) -> StatementType {
413        self.stmt_type
414    }
415
416    pub fn notices(&self) -> &[String] {
417        &self.notices
418    }
419
420    pub fn status(&self) -> &ParameterStatus {
421        &self.status
422    }
423
424    pub fn affected_rows_cnt(&self) -> Option<i32> {
425        self.row_cnt
426    }
427
428    pub fn row_cnt_format(&self) -> Option<Format> {
429        self.row_cnt_format
430    }
431
432    pub fn is_query(&self) -> bool {
433        self.stmt_type.is_query()
434    }
435
436    pub fn is_empty(&self) -> bool {
437        self.stmt_type == StatementType::EMPTY
438    }
439
440    pub fn is_copy_query_to_stdout(&self) -> bool {
441        self.is_copy_query_to_stdout
442    }
443
444    pub fn row_desc(&self) -> &[PgFieldDescriptor] {
445        &self.row_desc
446    }
447
448    pub fn values_stream(&mut self) -> &mut VS {
449        self.values_stream.as_mut().expect("no values stream")
450    }
451
452    /// Run the callback if there is one.
453    ///
454    /// This should only be called after the values stream has been exhausted. Multiple calls to
455    /// this function will be no-ops.
456    pub async fn run_callback(&mut self) -> Result<(), PsqlError> {
457        // Check if the stream is exhausted.
458        if let Some(values_stream) = &mut self.values_stream {
459            assert!(values_stream.next().await.is_none());
460        }
461
462        if let Some(callback) = self.callback.take() {
463            callback.await.map_err(PsqlError::SimpleQueryError)?;
464        }
465        Ok(())
466    }
467}
pgwire/pg_response.rs

pgwire/
pg_response.rs
