refactor(frontend): Move some pg wire value into common and make they…

… const (#14519)

src/common/src/lib.rs

@@ -91,6 +91,16 @@ pub const RW_VERSION: &str = env!("CARGO_PKG_VERSION");
 /// Placeholder for unknown git sha.
 pub const UNKNOWN_GIT_SHA: &str = "unknown";
 
+// The single source of truth of the pg parameters, Used in ConfigMap and current_cluster_version.
+// The version of PostgreSQL that Risingwave claims to be.
+pub const PG_VERSION: &str = "9.5.0";
+/// The version of PostgreSQL that Risingwave claims to be.
+pub const SERVER_VERSION_NUM: i32 = 90500;
+/// Shows the server-side character set encoding. At present, this parameter can be shown but not set, because the encoding is determined at database creation time. It is also the default value of `client_encoding`.
+pub const SERVER_ENCODING: &str = "UTF8";
+/// see <https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-STANDARD-CONFORMING-STRINGS>
+pub const STANDARD_CONFORMING_STRINGS: &str = "on";
+
 #[macro_export]
 macro_rules! git_sha {
     ($env:literal) => {
@@ -107,5 +117,8 @@ macro_rules! git_sha {
 pub const GIT_SHA: &str = git_sha!("GIT_SHA");
 
 pub fn current_cluster_version() -> String {
-    format!("PostgreSQL 9.5-RisingWave-{} ({})", RW_VERSION, GIT_SHA)
+    format!(
+        "PostgreSQL {}-RisingWave-{} ({})",
+        PG_VERSION, RW_VERSION, GIT_SHA
+    )
 }

src/common/src/session_config/mod.rs

@@ -31,6 +31,7 @@ use self::non_zero64::ConfigNonZeroU64;
 use crate::session_config::sink_decouple::SinkDecouple;
 use crate::session_config::transaction_isolation_level::IsolationLevel;
 pub use crate::session_config::visibility_mode::VisibilityMode;
+use crate::{PG_VERSION, SERVER_ENCODING, SERVER_VERSION_NUM, STANDARD_CONFORMING_STRINGS};
 
 pub const SESSION_CONFIG_LIST_SEP: &str = ", ";
 
@@ -175,19 +176,19 @@ pub struct ConfigMap {
     batch_parallelism: ConfigNonZeroU64,
 
     /// The version of PostgreSQL that Risingwave claims to be.
-    #[parameter(default = "9.5.0")]
+    #[parameter(default = PG_VERSION)]
     server_version: String,
 
     /// The version of PostgreSQL that Risingwave claims to be.
-    #[parameter(default = 90500)]
+    #[parameter(default = SERVER_VERSION_NUM)]
     server_version_num: i32,
 
     /// see <https://www.postgresql.org/docs/15/runtime-config-client.html#GUC-CLIENT-MIN-MESSAGES>
     #[parameter(default = "notice")]
     client_min_messages: String,
 
     /// see <https://www.postgresql.org/docs/15/runtime-config-client.html#GUC-CLIENT-ENCODING>
-    #[parameter(default = "UTF8", check_hook = check_client_encoding)]
+    #[parameter(default = SERVER_ENCODING, check_hook = check_client_encoding)]
     client_encoding: String,
 
     /// Enable decoupling sink and internal streaming graph or not
@@ -217,7 +218,7 @@ pub struct ConfigMap {
     row_security: bool,
 
     /// see <https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-STANDARD-CONFORMING-STRINGS>
-    #[parameter(default = "on")]
+    #[parameter(default = STANDARD_CONFORMING_STRINGS)]
     standard_conforming_strings: String,
 
     /// Set streaming rate limit (rows per second) for each parallelism for mv backfilling
@@ -234,7 +235,7 @@ pub struct ConfigMap {
     background_ddl: bool,
 
     /// Shows the server-side character set encoding. At present, this parameter can be shown but not set, because the encoding is determined at database creation time.
-    #[parameter(default = "UTF8")]
+    #[parameter(default = SERVER_ENCODING)]
     server_encoding: String,
 
     #[parameter(default = "hex", check_hook = check_bytea_output)]

src/utils/pgwire/src/pg_protocol.rs

@@ -28,6 +28,7 @@ use openssl::ssl::{SslAcceptor, SslContext, SslContextRef, SslMethod};
 use risingwave_common::types::DataType;
 use risingwave_common::util::panic::FutureCatchUnwindExt;
 use risingwave_common::util::query_log::*;
+use risingwave_common::{PG_VERSION, SERVER_ENCODING, STANDARD_CONFORMING_STRINGS};
 use risingwave_sqlparser::ast::Statement;
 use risingwave_sqlparser::parser::Parser;
 use thiserror_ext::AsReport;
@@ -973,13 +974,13 @@ where
 
     fn write_parameter_status_msg_no_flush(&mut self, status: &ParameterStatus) -> io::Result<()> {
         self.write_no_flush(&BeMessage::ParameterStatus(
-            BeParameterStatusMessage::ClientEncoding("UTF8"),
+            BeParameterStatusMessage::ClientEncoding(SERVER_ENCODING),
         ))?;
         self.write_no_flush(&BeMessage::ParameterStatus(
-            BeParameterStatusMessage::StandardConformingString("on"),
+            BeParameterStatusMessage::StandardConformingString(STANDARD_CONFORMING_STRINGS),
         ))?;
         self.write_no_flush(&BeMessage::ParameterStatus(
-            BeParameterStatusMessage::ServerVersion("9.5.0"),
+            BeParameterStatusMessage::ServerVersion(PG_VERSION),
         ))?;
         if let Some(application_name) = &status.application_name {
             self.write_no_flush(&BeMessage::ParameterStatus(