[yugabyte#13423] YSQL: Remove unused PgEnv class

Summary: PgEnv class is not used. Removing for code cleanup.

Test Plan: Jenkins

Reviewers: jason, alex

Reviewed By: alex

Subscribers: yql

Differential Revision: https://phabricator.dev.yugabyte.com/D18514

src/postgres/src/backend/utils/misc/pg_yb_utils.c

@@ -543,7 +543,7 @@ YBInitPostgresBackend(
 		 *
 		 * TODO: do we really need to DB name / username here?
 		 */
-		HandleYBStatus(YBCPgInitSession(/* pg_env */ NULL, db_name ? db_name : user_name));
+		HandleYBStatus(YBCPgInitSession(db_name ? db_name : user_name));
 	}
 }
 

src/yb/yql/pggate/pg_session.h

@@ -41,7 +41,6 @@
 
 #include "yb/yql/pggate/pg_client.h"
 #include "yb/yql/pggate/pg_gate_fwd.h"
-#include "yb/yql/pggate/pg_env.h"
 #include "yb/yql/pggate/pg_operation_buffer.h"
 #include "yb/yql/pggate/pg_perform_future.h"
 #include "yb/yql/pggate/pg_tabledesc.h"

src/yb/yql/pggate/pg_statement.h

@@ -29,7 +29,6 @@
 
 #include "yb/util/bytes_formatter.h"
 
-#include "yb/yql/pggate/pg_env.h"
 #include "yb/yql/pggate/pg_expr.h"
 #include "yb/yql/pggate/pg_memctx.h"
 #include "yb/yql/pggate/pg_session.h"

src/yb/yql/pggate/pg_truncate_colocated.h

@@ -16,7 +16,6 @@
 #define YB_YQL_PGGATE_PG_TRUNCATE_COLOCATED_H_
 
 #include "yb/yql/pggate/pg_dml_write.h"
-#include "yb/yql/pggate/pg_env.h"
 #include "yb/yql/pggate/pg_session.h"
 #include "yb/yql/pggate/pg_statement.h"
 

src/yb/yql/pggate/pggate.cc

@@ -442,20 +442,7 @@ const YBCPgTypeEntity *PgApiImpl::FindTypeEntity(int type_oid) {
 
 //--------------------------------------------------------------------------------------------------
 
-Status PgApiImpl::CreateEnv(PgEnv **pg_env) {
-  *pg_env = pg_env_.get();
-  return Status::OK();
-}
-
-Status PgApiImpl::DestroyEnv(PgEnv *pg_env) {
-  pg_env_ = nullptr;
-  return Status::OK();
-}
-
-//--------------------------------------------------------------------------------------------------
-
-Status PgApiImpl::InitSession(const PgEnv *pg_env,
-                              const string& database_name) {
+Status PgApiImpl::InitSession(const string& database_name) {
   CHECK(!pg_session_);
   auto session = make_scoped_refptr<PgSession>(&pg_client_,
                                                database_name,

src/yb/yql/pggate/pggate.h

@@ -41,7 +41,6 @@
 #include "yb/util/status_fwd.h"
 
 #include "yb/yql/pggate/pg_client.h"
-#include "yb/yql/pggate/pg_env.h"
 #include "yb/yql/pggate/pg_expr.h"
 #include "yb/yql/pggate/pg_gate_fwd.h"
 #include "yb/yql/pggate/pg_statement.h"
@@ -123,13 +122,9 @@ class PgApiImpl {
   void Interrupt();
   void ResetCatalogReadTime();
 
-  // Initialize ENV within which PGSQL calls will be executed.
-  Status CreateEnv(PgEnv **pg_env);
-  Status DestroyEnv(PgEnv *pg_env);
-
   // Initialize a session to process statements that come from the same client connection.
   // If database_name is empty, a session is created without connecting to any database.
-  Status InitSession(const PgEnv *pg_env, const std::string& database_name);
+  Status InitSession(const std::string& database_name);
 
   PgMemctx *CreateMemctx();
   Status DestroyMemctx(PgMemctx *memctx);
@@ -619,10 +614,6 @@ class PgApiImpl {
   // TODO Rename to client_ when YBClient is removed.
   PgClient pg_client_;
 
-  // TODO(neil) Map for environments (we should have just one ENV?). Environments should contain
-  // all the custom flags the PostgreSQL sets. We ignore them all for now.
-  PgEnv::SharedPtr pg_env_;
-
   scoped_refptr<server::HybridClock> clock_;
 
   // Local tablet-server shared memory segment handle.

src/yb/yql/pggate/test/pggate_test.cc

@@ -157,7 +157,7 @@ Status PggateTest::Init(const char *test_name, int num_tablet_servers) {
   YBCInitPgGate(type_table, count, callbacks);
 
   // Setup session.
-  CHECK_YBC_STATUS(YBCPgInitSession(nullptr /* pg_env */, nullptr /* database_name */));
+  CHECK_YBC_STATUS(YBCPgInitSession(nullptr /* database_name */));
 
   // Setup database
   SetupDB();

src/yb/yql/pggate/ybc_pg_typedefs.h

@@ -37,9 +37,6 @@
 extern "C" {
 #endif  // __cplusplus
 
-// TODO(neil) Handle to Env. Each Postgres process might need just one ENV, maybe more.
-YB_DEFINE_HANDLE_TYPE(PgEnv)
-
 // Handle to a session. Postgres should create one YBCPgSession per client connection.
 YB_DEFINE_HANDLE_TYPE(PgSession)
 

src/yb/yql/pggate/ybc_pggate.cc

@@ -40,7 +40,6 @@
 #include "yb/docdb/primitive_value.h"
 #include "yb/docdb/value_type.h"
 
-#include "yb/yql/pggate/pg_env.h"
 #include "yb/yql/pggate/pg_expr.h"
 #include "yb/yql/pggate/pg_gate_fwd.h"
 #include "yb/yql/pggate/pg_memctx.h"
@@ -163,18 +162,9 @@ const YBCPgCallbacks *YBCGetPgCallbacks() {
   return pgapi->pg_callbacks();
 }
 
-YBCStatus YBCPgCreateEnv(YBCPgEnv *pg_env) {
-  return ToYBCStatus(pgapi->CreateEnv(pg_env));
-}
-
-YBCStatus YBCPgDestroyEnv(YBCPgEnv pg_env) {
-  return ToYBCStatus(pgapi->DestroyEnv(pg_env));
-}
-
-YBCStatus YBCPgInitSession(const YBCPgEnv pg_env,
-                           const char *database_name) {
+YBCStatus YBCPgInitSession(const char *database_name) {
   const string db_name(database_name ? database_name : "");
-  return ToYBCStatus(pgapi->InitSession(pg_env, db_name));
+  return ToYBCStatus(pgapi->InitSession(db_name));
 }
 
 YBCPgMemctx YBCPgCreateMemctx() {

src/yb/yql/pggate/ybc_pggate.h

@@ -33,20 +33,16 @@ void YBCInterruptPgGate();
 //--------------------------------------------------------------------------------------------------
 // Environment and Session.
 
-// Initialize ENV within which PGSQL calls will be executed.
-YBCStatus YBCPgCreateEnv(YBCPgEnv *pg_env);
-YBCStatus YBCPgDestroyEnv(YBCPgEnv pg_env);
-
 // Initialize a session to process statements that come from the same client connection.
-YBCStatus YBCPgInitSession(const YBCPgEnv pg_env, const char *database_name);
+YBCStatus YBCPgInitSession(const char *database_name);
 
 // Initialize YBCPgMemCtx.
 // - Postgres uses memory context to hold all of its allocated space. Once all associated operations
 //   are done, the context is destroyed.
 // - There YugaByte objects are bound to Postgres operations. All of these objects' allocated
 //   memory will be held by YBCPgMemCtx, whose handle belongs to Postgres MemoryContext. Once all
 //   Postgres operations are done, associated YugaByte memory context (YBCPgMemCtx) will be
-//   destroyed toghether with Postgres memory context.
+//   destroyed together with Postgres memory context.
 YBCPgMemctx YBCPgCreateMemctx();
 YBCStatus YBCPgDestroyMemctx(YBCPgMemctx memctx);
 YBCStatus YBCPgResetMemctx(YBCPgMemctx memctx);