feat(frontend): support extended query protocol handle (risingwavelabs#8565)

ZENOTME · web-flow · commit 25a912767301 · 2023-03-16T13:04:50.000Z
diff --git a/src/frontend/src/handler/extended_handle.rs b/src/frontend/src/handler/extended_handle.rs
@@ -0,0 +1,94 @@
+// Copyright 2023 RisingWave Labs
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::sync::Arc;
+
+use bytes::Bytes;
+use pgwire::types::Format;
+use risingwave_common::error::{ErrorCode, Result};
+use risingwave_common::types::DataType;
+use risingwave_sqlparser::ast::Statement;
+
+use super::{query, HandlerArgs, RwPgResponse};
+use crate::binder::BoundStatement;
+use crate::session::SessionImpl;
+
+pub struct PrepareStatement {
+    pub statement: Statement,
+    pub bound_statement: BoundStatement,
+    pub param_types: Vec<DataType>,
+}
+
+pub struct Portal {
+    pub statement: Statement,
+    pub bound_statement: BoundStatement,
+    pub result_formats: Vec<Format>,
+}
+
+pub fn handle_parse(
+    session: Arc<SessionImpl>,
+    stmt: Statement,
+    specific_param_types: Vec<DataType>,
+) -> Result<PrepareStatement> {
+    session.clear_cancel_query_flag();
+    let str_sql = stmt.to_string();
+    let handler_args = HandlerArgs::new(session, &stmt, &str_sql)?;
+    match stmt {
+        Statement::Query(_)
+        | Statement::Insert { .. }
+        | Statement::Delete { .. }
+        | Statement::Update { .. } => query::handle_parse(handler_args, stmt, specific_param_types),
+        _ => Err(ErrorCode::NotSupported(
+            format!("Can't support {} in extended query mode now", str_sql,),
+            "".to_string(),
+        )
+        .into()),
+    }
+}
+
+pub fn handle_bind(
+    prepare_statement: PrepareStatement,
+    params: Vec<Bytes>,
+    param_formats: Vec<Format>,
+    result_formats: Vec<Format>,
+) -> Result<Portal> {
+    let PrepareStatement {
+        statement,
+        bound_statement,
+        ..
+    } = prepare_statement;
+    let bound_statement = bound_statement.bind_parameter(params, param_formats)?;
+    Ok(Portal {
+        statement,
+        bound_statement,
+        result_formats,
+    })
+}
+
+pub async fn handle_execute(session: Arc<SessionImpl>, portal: Portal) -> Result<RwPgResponse> {
+    session.clear_cancel_query_flag();
+    let str_sql = portal.statement.to_string();
+    let handler_args = HandlerArgs::new(session, &portal.statement, &str_sql)?;
+    match &portal.statement {
+        Statement::Query(_)
+        | Statement::Insert { .. }
+        | Statement::Delete { .. }
+        | Statement::Update { .. } => query::handle_execute(handler_args, portal).await,
+        _ => Err(ErrorCode::NotSupported(
+            format!("Can't support {} in extended query mode now", str_sql,),
+            "".to_string(),
+        )
+        .into()),
+    }
+}
diff --git a/src/frontend/src/handler/mod.rs b/src/frontend/src/handler/mod.rs
@@ -59,6 +59,7 @@ pub mod drop_table;
 pub mod drop_user;
 mod drop_view;
 pub mod explain;
+pub mod extended_handle;
 mod flush;
 pub mod handle_privilege;
 pub mod privilege;
diff --git a/src/frontend/src/handler/query.rs b/src/frontend/src/handler/query.rs
@@ -24,8 +24,10 @@ use postgres_types::FromSql;
 use risingwave_common::catalog::Schema;
 use risingwave_common::error::{ErrorCode, Result, RwError};
 use risingwave_common::session_config::QueryMode;
+use risingwave_common::types::DataType;
 use risingwave_sqlparser::ast::{SetExpr, Statement};
 
+use super::extended_handle::{Portal, PrepareStatement};
 use super::{PgResponseStream, RwPgResponse};
 use crate::binder::{Binder, BoundSetExpr, BoundStatement};
 use crate::handler::flush::do_flush;
@@ -74,6 +76,20 @@ fn must_run_in_distributed_mode(stmt: &Statement) -> Result<bool> {
     ) | is_insert_using_select(stmt))
 }
 
+fn must_run_in_local_mode(bound: &BoundStatement) -> bool {
+    let mut must_local = false;
+
+    if let BoundStatement::Query(query) = &bound {
+        if let BoundSetExpr::Select(select) = &query.body
+            && let Some(relation) = &select.from
+            && relation.contains_sys_table() {
+                must_local = true;
+        }
+    }
+
+    must_local
+}
+
 pub fn gen_batch_query_plan(
     session: &SessionImpl,
     context: OptimizerContextRef,
@@ -89,16 +105,9 @@ pub fn gen_batch_query_plan(
     let check_items = resolve_privileges(&bound);
     session.check_privileges(&check_items)?;
 
-    let mut planner = Planner::new(context);
+    let must_local = must_run_in_local_mode(&bound);
 
-    let mut must_local = false;
-    if let BoundStatement::Query(query) = &bound {
-        if let BoundSetExpr::Select(select) = &query.body
-            && let Some(relation) = &select.from
-            && relation.contains_sys_table() {
-                must_local = true;
-        }
-    }
+    let mut planner = Planner::new(context);
 
     let mut logical = planner.plan(bound)?;
     let schema = logical.schema();
@@ -339,3 +348,227 @@ pub async fn local_execute(
 
     Ok(execution.stream_rows())
 }
+
+pub fn handle_parse(
+    handler_args: HandlerArgs,
+    statement: Statement,
+    specific_param_types: Vec<DataType>,
+) -> Result<PrepareStatement> {
+    let session = handler_args.session;
+    let mut binder = Binder::new_with_param_types(&session, specific_param_types);
+    let bound_statement = binder.bind(statement.clone())?;
+
+    let check_items = resolve_privileges(&bound_statement);
+    session.check_privileges(&check_items)?;
+
+    let param_types = binder.export_param_types()?;
+
+    Ok(PrepareStatement {
+        statement,
+        bound_statement,
+        param_types,
+    })
+}
+
+pub async fn handle_execute(handler_args: HandlerArgs, portal: Portal) -> Result<RwPgResponse> {
+    let Portal {
+        statement,
+        bound_statement,
+        result_formats,
+    } = portal;
+
+    let stmt_type = StatementType::infer_from_statement(&statement)
+        .map_err(|err| RwError::from(ErrorCode::InvalidInputSyntax(err)))?;
+    let session = handler_args.session.clone();
+    let query_start_time = Instant::now();
+    let only_checkpoint_visible = handler_args.session.config().only_checkpoint_visible();
+    let mut notice = String::new();
+
+    // Subblock to make sure PlanRef (an Rc) is dropped before `await` below.
+    let (plan_fragmenter, query_mode, output_schema) = {
+        let context = OptimizerContext::from_handler_args(handler_args);
+
+        let must_dist = must_run_in_distributed_mode(&statement)?;
+        let must_local = must_run_in_local_mode(&bound_statement);
+
+        let mut planner = Planner::new(context.into());
+
+        let mut logical = planner.plan(bound_statement)?;
+        let schema = logical.schema();
+        let batch_plan = logical.gen_batch_plan()?;
+
+        let query_mode = match (must_dist, must_local) {
+            (true, true) => {
+                return Err(ErrorCode::InternalError(
+                    "the query is forced to both local and distributed mode by optimizer"
+                        .to_owned(),
+                )
+                .into())
+            }
+            (true, false) => QueryMode::Distributed,
+            (false, true) => QueryMode::Local,
+            (false, false) => match session.config().get_query_mode() {
+                QueryMode::Auto => determine_query_mode(batch_plan.clone()),
+                QueryMode::Local => QueryMode::Local,
+                QueryMode::Distributed => QueryMode::Distributed,
+            },
+        };
+
+        let physical = match query_mode {
+            QueryMode::Auto => unreachable!(),
+            QueryMode::Local => logical.gen_batch_local_plan(batch_plan)?,
+            QueryMode::Distributed => logical.gen_batch_distributed_plan(batch_plan)?,
+        };
+
+        let context = physical.plan_base().ctx.clone();
+        tracing::trace!(
+            "Generated query plan: {:?}, query_mode:{:?}",
+            physical.explain_to_string()?,
+            query_mode
+        );
+        let plan_fragmenter = BatchPlanFragmenter::new(
+            session.env().worker_node_manager_ref(),
+            session.env().catalog_reader().clone(),
+            session.config().get_batch_parallelism(),
+            physical,
+        )?;
+        context.append_notice(&mut notice);
+        (plan_fragmenter, query_mode, schema)
+    };
+    let query = plan_fragmenter.generate_complete_query().await?;
+    tracing::trace!("Generated query after plan fragmenter: {:?}", &query);
+
+    let pg_descs = output_schema
+        .fields()
+        .iter()
+        .map(to_pg_field)
+        .collect::<Vec<PgFieldDescriptor>>();
+    let column_types = output_schema
+        .fields()
+        .iter()
+        .map(|f| f.data_type())
+        .collect_vec();
+
+    // Used in counting row count.
+    let first_field_format = result_formats.first().copied().unwrap_or(Format::Text);
+
+    let mut row_stream = {
+        let query_epoch = session.config().get_query_epoch();
+        let query_snapshot = if let Some(query_epoch) = query_epoch {
+            PinnedHummockSnapshot::Other(query_epoch)
+        } else {
+            // Acquire hummock snapshot for execution.
+            // TODO: if there's no table scan, we don't need to acquire snapshot.
+            let hummock_snapshot_manager = session.env().hummock_snapshot_manager();
+            let query_id = query.query_id().clone();
+            let pinned_snapshot = hummock_snapshot_manager.acquire(&query_id).await?;
+            PinnedHummockSnapshot::FrontendPinned(pinned_snapshot, only_checkpoint_visible)
+        };
+        match query_mode {
+            QueryMode::Auto => unreachable!(),
+            QueryMode::Local => PgResponseStream::LocalQuery(DataChunkToRowSetAdapter::new(
+                local_execute(session.clone(), query, query_snapshot).await?,
+                column_types,
+                result_formats,
+                session.clone(),
+            )),
+            // Local mode do not support cancel tasks.
+            QueryMode::Distributed => {
+                PgResponseStream::DistributedQuery(DataChunkToRowSetAdapter::new(
+                    distribute_execute(session.clone(), query, query_snapshot).await?,
+                    column_types,
+                    result_formats,
+                    session.clone(),
+                ))
+            }
+        }
+    };
+
+    let rows_count: Option<i32> = match stmt_type {
+        StatementType::SELECT
+        | StatementType::INSERT_RETURNING
+        | StatementType::DELETE_RETURNING
+        | StatementType::UPDATE_RETURNING => None,
+
+        StatementType::INSERT | StatementType::DELETE | StatementType::UPDATE => {
+            let first_row_set = row_stream.next().await;
+            let first_row_set = match first_row_set {
+                None => {
+                    return Err(RwError::from(ErrorCode::InternalError(
+                        "no affected rows in output".to_string(),
+                    )))
+                }
+                Some(row) => {
+                    row.map_err(|err| RwError::from(ErrorCode::InternalError(format!("{}", err))))?
+                }
+            };
+            let affected_rows_str = first_row_set[0].values()[0]
+                .as_ref()
+                .expect("compute node should return affected rows in output");
+            if let Format::Binary = first_field_format {
+                Some(
+                    i64::from_sql(&postgres_types::Type::INT8, affected_rows_str)
+                        .unwrap()
+                        .try_into()
+                        .expect("affected rows count large than i32"),
+                )
+            } else {
+                Some(
+                    String::from_utf8(affected_rows_str.to_vec())
+                        .unwrap()
+                        .parse()
+                        .unwrap_or_default(),
+                )
+            }
+        }
+        _ => unreachable!(),
+    };
+
+    // We need to do some post work after the query is finished and before the `Complete` response
+    // it sent. This is achieved by the `callback` in `PgResponse`.
+    let callback = async move {
+        // Implicitly flush the writes.
+        if session.config().get_implicit_flush() && stmt_type.is_dml() {
+            do_flush(&session).await?;
+        }
+
+        // update some metrics
+        match query_mode {
+            QueryMode::Auto => unreachable!(),
+            QueryMode::Local => {
+                session
+                    .env()
+                    .frontend_metrics
+                    .latency_local_execution
+                    .observe(query_start_time.elapsed().as_secs_f64());
+
+                session
+                    .env()
+                    .frontend_metrics
+                    .query_counter_local_execution
+                    .inc();
+            }
+            QueryMode::Distributed => {
+                session
+                    .env()
+                    .query_manager()
+                    .query_metrics
+                    .query_latency
+                    .observe(query_start_time.elapsed().as_secs_f64());
+
+                session
+                    .env()
+                    .query_manager()
+                    .query_metrics
+                    .completed_query_counter
+                    .inc();
+            }
+        }
+
+        Ok(())
+    };
+
+    Ok(PgResponse::new_for_stream_extra(
+        stmt_type, rows_count, row_stream, pg_descs, notice, callback,
+    ))
+}
