refactor(frontend): use #[derive(Fields)] in statement handlers

src/common/fields-derive/src/lib.rs

@@ -16,7 +16,7 @@ use proc_macro2::TokenStream;
 use quote::quote;
 use syn::{Data, DeriveInput, Result};
 
-#[proc_macro_derive(Fields, attributes(primary_key))]
+#[proc_macro_derive(Fields, attributes(primary_key, fields))]
 pub fn fields(tokens: proc_macro::TokenStream) -> proc_macro::TokenStream {
     inner(tokens.into()).into()
 }
@@ -46,6 +46,16 @@ fn gen(tokens: TokenStream) -> Result<TokenStream> {
         ));
     };
 
+    let style = get_style(&input);
+    if let Some(style) = &style {
+        if !["Title Case", "TITLE CASE", "snake_case"].contains(&style.value().as_str()) {
+            return Err(syn::Error::new_spanned(
+                style,
+                "only `Title Case`, `TITLE CASE`, and `snake_case` are supported",
+            ));
+        }
+    }
+
     let fields_rw: Vec<TokenStream> = struct_
         .fields
         .iter()
@@ -55,6 +65,12 @@ fn gen(tokens: TokenStream) -> Result<TokenStream> {
             if name.starts_with("r#") {
                 name = name[2..].to_string();
             }
+            // cast style
+            match style.as_ref().map_or(String::new(), |f| f.value()).as_str() {
+                "Title Case" => name = to_title_case(&name),
+                "TITLE CASE" => name = to_title_case(&name).to_uppercase(),
+                _ => {}
+            }
             let ty = &field.ty;
             quote! {
                 (#name, <#ty as ::risingwave_common::types::WithDataType>::default_data_type())
@@ -132,6 +148,46 @@ fn get_primary_key(input: &syn::DeriveInput) -> Option<Vec<usize>> {
     None
 }
 
+/// Get name style from `#[fields(style = "xxx")]` attribute.
+fn get_style(input: &syn::DeriveInput) -> Option<syn::LitStr> {
+    let style = input.attrs.iter().find_map(|attr| match &attr.meta {
+        syn::Meta::List(list) if list.path.is_ident("fields") => {
+            let name_value: syn::MetaNameValue = syn::parse2(list.tokens.clone()).ok()?;
+            if name_value.path.is_ident("style") {
+                Some(name_value.value)
+            } else {
+                None
+            }
+        }
+        _ => None,
+    })?;
+    match style {
+        syn::Expr::Lit(lit) => match lit.lit {
+            syn::Lit::Str(s) => Some(s),
+            _ => None,
+        },
+        _ => None,
+    }
+}
+
+/// Convert `snake_case` to `Title Case`.
+fn to_title_case(s: &str) -> String {
+    let mut title = String::new();
+    let mut next_upper = true;
+    for c in s.chars() {
+        if c == '_' {
+            title.push(' ');
+            next_upper = true;
+        } else if next_upper {
+            title.push(c.to_uppercase().next().unwrap());
+            next_upper = false;
+        } else {
+            title.push(c);
+        }
+    }
+    title
+}
+
 #[cfg(test)]
 mod tests {
     use indoc::indoc;

src/frontend/src/handler/cancel_job.rs

@@ -12,14 +12,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use itertools::Itertools;
-use pgwire::pg_field_descriptor::PgFieldDescriptor;
 use pgwire::pg_response::{PgResponse, StatementType};
-use pgwire::types::Row;
-use risingwave_common::types::DataType;
+use risingwave_common::types::Fields;
 use risingwave_pb::meta::cancel_creating_jobs_request::{CreatingJobIds, PbJobs};
 use risingwave_sqlparser::ast::JobIdents;
 
+use super::RwPgResponseBuilderExt;
 use crate::error::Result;
 use crate::handler::{HandlerArgs, RwPgResponse};
 
@@ -36,16 +34,14 @@ pub(super) async fn handle_cancel(
         .await?;
     let rows = canceled_jobs
         .into_iter()
-        .map(|id| Row::new(vec![Some(id.to_string().into())]))
-        .collect_vec();
+        .map(|id| CancelRow { id: id.to_string() });
     Ok(PgResponse::builder(StatementType::CANCEL_COMMAND)
-        .values(
-            rows.into(),
-            vec![PgFieldDescriptor::new(
-                "Id".to_string(),
-                DataType::Varchar.to_oid(),
-                DataType::Varchar.type_len(),
-            )],
-        )
+        .rows(rows)
         .into())
 }
+
+#[derive(Fields)]
+#[fields(style = "Title Case")]
+struct CancelRow {
+    id: String,
+}

src/frontend/src/handler/describe.rs

@@ -17,17 +17,16 @@ use std::fmt::Display;
 use itertools::Itertools;
 use pgwire::pg_field_descriptor::PgFieldDescriptor;
 use pgwire::pg_response::{PgResponse, StatementType};
-use pgwire::types::Row;
 use risingwave_common::catalog::{ColumnCatalog, ColumnDesc};
-use risingwave_common::types::DataType;
+use risingwave_common::types::Fields;
 use risingwave_sqlparser::ast::{display_comma_separated, ObjectName};
 
-use super::RwPgResponse;
+use super::show::ShowColumnRow;
+use super::{fields_to_descriptors, RwPgResponse};
 use crate::binder::{Binder, Relation};
 use crate::catalog::CatalogError;
 use crate::error::Result;
-use crate::handler::util::col_descs_to_rows;
-use crate::handler::HandlerArgs;
+use crate::handler::{HandlerArgs, RwPgResponseBuilderExt};
 
 pub fn handle_describe(handler_args: HandlerArgs, object_name: ObjectName) -> Result<RwPgResponse> {
     let session = handler_args.session;
@@ -156,7 +155,10 @@ pub fn handle_describe(handler_args: HandlerArgs, object_name: ObjectName) -> Re
         };
 
     // Convert all column descs to rows
-    let mut rows = col_descs_to_rows(columns);
+    let mut rows = columns
+        .into_iter()
+        .flat_map(ShowColumnRow::from_catalog)
+        .collect_vec();
 
     fn concat<T>(display_elems: impl IntoIterator<Item = T>) -> String
     where
@@ -170,96 +172,68 @@ pub fn handle_describe(handler_args: HandlerArgs, object_name: ObjectName) -> Re
 
     // Convert primary key to rows
     if !pk_columns.is_empty() {
-        rows.push(Row::new(vec![
-            Some("primary key".into()),
-            Some(concat(pk_columns.iter().map(|x| &x.name)).into()),
-            None, // Is Hidden
-            None, // Description
-        ]));
+        rows.push(ShowColumnRow {
+            name: "primary key".into(),
+            r#type: concat(pk_columns.iter().map(|x| &x.name)),
+            is_hidden: None,
+            description: None,
+        });
     }
 
     // Convert distribution keys to rows
     if !dist_columns.is_empty() {
-        rows.push(Row::new(vec![
-            Some("distribution key".into()),
-            Some(concat(dist_columns.iter().map(|x| &x.name)).into()),
-            None, // Is Hidden
-            None, // Description
-        ]));
+        rows.push(ShowColumnRow {
+            name: "distribution key".into(),
+            r#type: concat(dist_columns.iter().map(|x| &x.name)),
+            is_hidden: None,
+            description: None,
+        });
     }
 
     // Convert all indexes to rows
     rows.extend(indices.iter().map(|index| {
         let index_display = index.display();
 
-        Row::new(vec![
-            Some(index.name.clone().into()),
-            if index_display.include_columns.is_empty() {
-                Some(
-                    format!(
-                        "index({}) distributed by({})",
-                        display_comma_separated(&index_display.index_columns_with_ordering),
-                        display_comma_separated(&index_display.distributed_by_columns),
-                    )
-                    .into(),
+        ShowColumnRow {
+            name: index.name.clone(),
+            r#type: if index_display.include_columns.is_empty() {
+                format!(
+                    "index({}) distributed by({})",
+                    display_comma_separated(&index_display.index_columns_with_ordering),
+                    display_comma_separated(&index_display.distributed_by_columns),
                 )
             } else {
-                Some(
-                    format!(
-                        "index({}) include({}) distributed by({})",
-                        display_comma_separated(&index_display.index_columns_with_ordering),
-                        display_comma_separated(&index_display.include_columns),
-                        display_comma_separated(&index_display.distributed_by_columns),
-                    )
-                    .into(),
+                format!(
+                    "index({}) include({}) distributed by({})",
+                    display_comma_separated(&index_display.index_columns_with_ordering),
+                    display_comma_separated(&index_display.include_columns),
+                    display_comma_separated(&index_display.distributed_by_columns),
                 )
             },
-            // Is Hidden
-            None,
-            // Description
+            is_hidden: None,
             // TODO: index description
-            None,
-        ])
+            description: None,
+        }
     }));
 
-    rows.push(Row::new(vec![
-        Some("table description".into()),
-        Some(relname.into()),
-        None,                        // Is Hidden
-        description.map(Into::into), // Description
-    ]));
+    rows.push(ShowColumnRow {
+        name: "table description".into(),
+        r#type: relname,
+        is_hidden: None,
+        description: description.map(Into::into),
+    });
 
     // TODO: table name and description as title of response
     // TODO: recover the original user statement
     Ok(PgResponse::builder(StatementType::DESCRIBE)
-        .values(
-            rows.into(),
-            vec![
-                PgFieldDescriptor::new(
-                    "Name".to_owned(),
-                    DataType::Varchar.to_oid(),
-                    DataType::Varchar.type_len(),
-                ),
-                PgFieldDescriptor::new(
-                    "Type".to_owned(),
-                    DataType::Varchar.to_oid(),
-                    DataType::Varchar.type_len(),
-                ),
-                PgFieldDescriptor::new(
-                    "Is Hidden".to_owned(),
-                    DataType::Varchar.to_oid(),
-                    DataType::Varchar.type_len(),
-                ),
-                PgFieldDescriptor::new(
-                    "Description".to_owned(),
-                    DataType::Varchar.to_oid(),
-                    DataType::Varchar.type_len(),
-                ),
-            ],
-        )
+        .rows(rows)
         .into())
 }
 
+pub fn infer_describe() -> Vec<PgFieldDescriptor> {
+    fields_to_descriptors(ShowColumnRow::fields())
+}
+
 #[cfg(test)]
 mod tests {
     use std::collections::HashMap;

src/frontend/src/handler/explain.rs

@@ -12,12 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use itertools::Itertools;
-use pgwire::pg_field_descriptor::PgFieldDescriptor;
 use pgwire::pg_response::{PgResponse, StatementType};
-use pgwire::types::Row;
 use risingwave_common::bail_not_implemented;
-use risingwave_common::types::DataType;
+use risingwave_common::types::Fields;
 use risingwave_sqlparser::ast::{ExplainOptions, ExplainType, Statement};
 use thiserror_ext::AsReport;
 
@@ -27,7 +24,7 @@ use super::create_sink::{gen_sink_plan, get_partition_compute_info};
 use super::create_table::ColumnIdGenerator;
 use super::query::gen_batch_plan_by_statement;
 use super::util::SourceSchemaCompatExt;
-use super::RwPgResponse;
+use super::{RwPgResponse, RwPgResponseBuilderExt};
 use crate::error::{ErrorCode, Result};
 use crate::handler::create_table::handle_create_table_plan;
 use crate::handler::HandlerArgs;
@@ -254,20 +251,17 @@ pub async fn handle_explain(
         }
     }
 
-    let rows = blocks
-        .iter()
-        .flat_map(|b| b.lines().map(|l| l.to_owned()))
-        .map(|l| Row::new(vec![Some(l.into())]))
-        .collect_vec();
+    let rows = blocks.iter().flat_map(|b| b.lines()).map(|l| ExplainRow {
+        query_plan: l.into(),
+    });
 
     Ok(PgResponse::builder(StatementType::EXPLAIN)
-        .values(
-            rows.into(),
-            vec![PgFieldDescriptor::new(
-                "QUERY PLAN".to_owned(),
-                DataType::Varchar.to_oid(),
-                DataType::Varchar.type_len(),
-            )],
-        )
+        .rows(rows)
         .into())
 }
+
+#[derive(Fields)]
+#[fields(style = "TITLE CASE")]
+struct ExplainRow {
+    query_plan: String,
+}