minisql/server/src/proto_wrapper.rs
2024-02-01 22:27:58 +01:00

142 lines
4.2 KiB
Rust

use async_trait::async_trait;
use minisql::operation::ColumnSelection;
use minisql::restricted_row::RestrictedRow;
use minisql::schema::{Column, TableSchema};
use proto::message::backend::{
BackendMessage, ColumnDescription, CommandCompleteData, DataRowData, ErrorResponseData,
ReadyForQueryData, RowDescriptionData,
};
use proto::message::primitive::pglist::PgList;
use proto::message::primitive::pgoid::PgOid;
use proto::writer::backend::BackendProtoWriter;
use std::fmt;
pub enum CompleteStatus {
Insert { oid: i32, rows: i32 },
Delete(usize),
Select(usize),
CreateTable,
CreateIndex,
}
impl fmt::Display for CompleteStatus {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
CompleteStatus::Insert { oid, rows } => write!(f, "INSERT {} {}", oid, rows),
CompleteStatus::Delete(rows) => write!(f, "DELETE {}", rows),
CompleteStatus::Select(rows) => write!(f, "SELECT {}", rows),
CompleteStatus::CreateTable => write!(f, "CREATE TABLE"),
CompleteStatus::CreateIndex => write!(f, "CREATE INDEX"),
}
}
}
#[async_trait]
pub trait ServerProto {
async fn write_error_message(&mut self, error_message: &str) -> anyhow::Result<()>;
async fn write_ready_for_query(&mut self) -> anyhow::Result<()>;
async fn write_empty_query(&mut self) -> anyhow::Result<()>;
async fn write_table_header(
&mut self,
table_schema: &TableSchema,
columns: &ColumnSelection,
) -> anyhow::Result<()>;
async fn write_table_row(&mut self, row: &RestrictedRow) -> anyhow::Result<()>;
async fn write_command_complete(&mut self, status: CompleteStatus) -> anyhow::Result<()>;
}
#[async_trait]
impl<W> ServerProto for W
where
W: BackendProtoWriter + Send,
{
async fn write_error_message(&mut self, error_message: &str) -> anyhow::Result<()> {
self.write_proto(
ErrorResponseData {
code: b'M',
message: format!("{error_message}\0").into(),
}
.into(),
)
.await?;
Ok(())
}
async fn write_ready_for_query(&mut self) -> anyhow::Result<()> {
self.write_proto(ReadyForQueryData { status: b'I' }.into())
.await?;
Ok(())
}
async fn write_empty_query(&mut self) -> anyhow::Result<()> {
self.write_proto(BackendMessage::EmptyQueryResponse).await?;
Ok(())
}
async fn write_table_header(
&mut self,
table_schema: &TableSchema,
columns: &ColumnSelection,
) -> anyhow::Result<()> {
let columns = columns
.iter()
.map(|column| column_to_description(table_schema, *column))
.collect::<anyhow::Result<Vec<ColumnDescription>>>()?;
self.write_proto(
RowDescriptionData {
columns: columns.into(),
}
.into(),
)
.await?;
Ok(())
}
async fn write_table_row(&mut self, row: &RestrictedRow) -> anyhow::Result<()> {
let values = row
.iter()
.map(|(_, value)| value.as_text_bytes().into())
.collect::<Vec<PgList<u8, i32>>>();
self.write_proto(BackendMessage::DataRow(DataRowData {
columns: values.into(),
}))
.await?;
Ok(())
}
async fn write_command_complete(&mut self, status: CompleteStatus) -> anyhow::Result<()> {
self.write_proto(BackendMessage::CommandComplete(CommandCompleteData {
tag: status.to_string().into(),
}))
.await?;
Ok(())
}
}
fn column_to_description(
schema: &TableSchema,
column: Column,
) -> anyhow::Result<ColumnDescription> {
let table_name = schema.table_name();
let table_oid = PgOid::from_unique_name(table_name);
let column_type = schema.column_type(column);
let name = schema.column_name_from_column(column);
let column_index = column.try_into()?;
let type_oid = column_type.type_oid();
let type_size = column_type.type_size();
Ok(ColumnDescription {
name: name.to_string().into(),
table_oid,
column_index,
type_oid,
type_size,
type_modifier: -1,
format_code: 0, // text format
})
}