Struct SessionImpl 

pub struct SessionImpl {

    env: FrontendEnv,
    auth_context: Arc<RwLock<AuthContext>>,
    user_authenticator: UserAuthenticator,
    config_map: Arc<RwLock<SessionConfig>>,
    notice_tx: UnboundedSender<String>,
    notice_rx: Mutex<UnboundedReceiver<String>>,
    id: (i32, i32),
    peer_addr: AddressRef,
    txn: Arc<Mutex<State>>,
    current_query_cancel_flag: Mutex<Option<ShutdownSender>>,
    exec_context: Mutex<Option<Weak<ExecContext>>>,
    last_idle_instant: Arc<Mutex<Option<Instant>>>,
    cursor_manager: Arc<CursorManager>,
    temporary_source_manager: Arc<Mutex<TemporarySourceManager>>,
    staging_catalog_manager: Arc<Mutex<StagingCatalogManager>>,
}

Fields

env: FrontendEnv

auth_context: Arc<RwLock<AuthContext>>

user_authenticator: UserAuthenticator

Used for user authentication.

config_map: Arc<RwLock<SessionConfig>>

Stores the value of configurations.

notice_tx: UnboundedSender<String>

Channel sender for frontend handler to send notices.

notice_rx: Mutex<UnboundedReceiver<String>>

Channel receiver for pgwire to take notices and send to clients.

id: (i32, i32)

Identified by process_id, secret_key. Corresponds to SessionManager.

peer_addr: AddressRef

Client address

txn: Arc<Mutex<State>>

Transaction state. TODO: get rid of the Mutex here as a workaround if the Send requirement of async functions, there should actually be no contention.

current_query_cancel_flag: Mutex<Option<ShutdownSender>>

Query cancel flag. This flag is set only when current query is executed in local mode, and used to cancel local query.

exec_context: Mutex<Option<Weak<ExecContext>>>

execution context represents the lifetime of a running SQL in the current session

last_idle_instant: Arc<Mutex<Option<Instant>>>

Last idle instant

cursor_manager: Arc<CursorManager>

temporary_source_manager: Arc<Mutex<TemporarySourceManager>>

temporary sources for the current session

staging_catalog_manager: Arc<Mutex<StagingCatalogManager>>

staging catalogs for the current session

Implementations

impl SessionImpl

pub fn check_privileges(&self, items: &[ObjectCheckItem]) -> Result<()>

Check whether the user of the current session has privileges in items.

pub fn is_super_user(&self) -> bool

Returns true if the user of the current session is a super user.

pub fn check_privilege_for_drop_alter( &self, schema_name: &str, relation: &impl OwnedByUserCatalog, ) -> Result<()>

Check whether the user of the current session has the privilege to drop or alter the relation relation in the schema with name schema_name.

Note that the right to drop or alter in PostgreSQL is special and not covered by the general GRANTs.

The right to drop an object, or to alter its definition in any way, is not treated as a grantable privilege; it is inherent in the owner, and cannot be granted or revoked.

Reference: https://www.postgresql.org/docs/current/sql-grant.html

pub fn check_privilege_for_drop_alter_db_schema( &self, db_schema: &impl OwnedByUserCatalog, ) -> Result<()>

Check whether the user of the current session has the privilege to drop or alter the db_schema, which is either a database or schema.

Only the owner of the database, or a superuser, can drop a database.

Reference: https://www.postgresql.org/docs/current/manage-ag-dropdb.html

A schema can only be dropped by its owner or a superuser.

Reference: https://www.postgresql.org/docs/current/sql-dropschema.html

impl SessionImpl

pub fn txn_begin_implicit(&self) -> ImplicitAutoCommitGuard

Starts an implicit transaction if there’s no explicit transaction in progress. Called at the beginning of handling each statement.

Returns a guard that auto commits the implicit transaction when dropped.

pub fn txn_begin_explicit(&self, access_mode: AccessMode)

Starts an explicit transaction with the specified access mode from START TRANSACTION.

pub fn txn_commit_explicit(&self)

Commits an explicit transaction.

pub fn txn_rollback_explicit(&self)

Rollbacks an explicit transaction.

fn txn_ctx(&self) -> MappedMutexGuard<'_, Context>

Returns the transaction context.

pub fn get_pinned_snapshot(&self) -> Option<ReadSnapshot>

pub fn unpin_snapshot(&self)

Unpin snapshot by replacing the snapshot with None.

pub fn pinned_snapshot(&self) -> ReadSnapshot

Acquires and pins a snapshot for the current transaction.

If a snapshot is already acquired, returns it directly.

impl SessionImpl

pub fn txn_write_guard(&self) -> Result<WriteGuard>

Returns a WriteGuard, or an error if write operations are not permitted in the current transaction.

pub fn catalog_writer(&self) -> Result<&dyn CatalogWriter>

Returns the catalog writer, if write operations are permitted in the current transaction.

pub fn user_info_writer(&self) -> Result<&dyn UserInfoWriter>

Returns the user info writer, if write operations are permitted in the current transaction.

impl SessionImpl

pub(crate) fn new( env: FrontendEnv, auth_context: AuthContext, user_authenticator: UserAuthenticator, id: SessionId, peer_addr: AddressRef, session_config: SessionConfig, ) -> Self

pub(crate) fn env(&self) -> &FrontendEnv

pub fn auth_context(&self) -> Arc<AuthContext>

pub fn database(&self) -> String

pub fn database_id(&self) -> DatabaseId

pub fn user_name(&self) -> String

pub fn user_id(&self) -> u32

pub fn update_database(&self, database: String)

pub fn shared_config(&self) -> Arc<RwLock<SessionConfig>>

pub fn config(&self) -> RwLockReadGuard<'_, SessionConfig>

pub fn set_config(&self, key: &str, value: String) -> Result<String>

pub fn reset_config(&self, key: &str) -> Result<String>

pub fn set_config_report( &self, key: &str, value: Option<String>, reporter: impl ConfigReporter, ) -> Result<String>

pub fn session_id(&self) -> SessionId

pub fn running_sql(&self) -> Option<Arc<str>>

pub fn get_cursor_manager(&self) -> Arc<CursorManager>

pub fn peer_addr(&self) -> &Address

pub fn elapse_since_running_sql(&self) -> Option<u128>

pub fn elapse_since_last_idle_instant(&self) -> Option<u128>

pub fn check_relation_name_duplicated( &self, name: ObjectName, stmt_type: StatementType, if_not_exists: bool, ) -> Result<Either<(), RwPgResponse>, CheckRelationError>

pub fn check_secret_name_duplicated(&self, name: ObjectName) -> Result<()>

pub fn check_connection_name_duplicated(&self, name: ObjectName) -> Result<()>

pub fn check_function_name_duplicated( &self, stmt_type: StatementType, name: ObjectName, arg_types: &[DataType], if_not_exists: bool, ) -> Result<Either<(), RwPgResponse>>

pub fn get_database_and_schema_id_for_create( &self, schema_name: Option<String>, ) -> Result<(DatabaseId, SchemaId)>

Also check if the user has the privilege to create in the schema.

pub fn get_connection_by_name( &self, schema_name: Option<String>, connection_name: &str, ) -> Result<Arc<ConnectionCatalog>>

pub fn get_subscription_by_schema_id_name( &self, schema_id: SchemaId, subscription_name: &str, ) -> Result<Arc<SubscriptionCatalog>>

pub fn get_subscription_by_name( &self, schema_name: Option<String>, subscription_name: &str, ) -> Result<Arc<SubscriptionCatalog>>

pub fn get_table_by_id(&self, table_id: &TableId) -> Result<Arc<TableCatalog>>

pub fn get_table_by_name( &self, table_name: &str, db_id: DatabaseId, schema_id: SchemaId, ) -> Result<Arc<TableCatalog>>

pub fn get_secret_by_name( &self, schema_name: Option<String>, secret_name: &str, ) -> Result<Arc<SecretCatalog>>

pub fn list_change_log_epochs( &self, table_id: TableId, min_epoch: u64, max_count: u32, ) -> Result<Vec<u64>>

pub fn clear_cancel_query_flag(&self)

pub fn reset_cancel_query_flag(&self) -> ShutdownToken

pub fn cancel_current_query(&self)

pub fn cancel_current_creating_job(&self)

pub async fn run_statement( self: Arc<Self>, sql: Arc<str>, formats: Vec<Format>, ) -> Result<PgResponse<PgResponseStream>, BoxedError>

This function only used for test now. Maybe we can remove it in the future.

pub fn notice_to_user(&self, str: impl Into<String>)

pub fn is_barrier_read(&self) -> bool

pub fn statement_timeout(&self) -> Duration

pub fn create_temporary_source(&self, source: SourceCatalog)

pub fn get_temporary_source(&self, name: &str) -> Option<SourceCatalog>

pub fn drop_temporary_source(&self, name: &str)

pub fn temporary_source_manager(&self) -> TemporarySourceManager

pub fn create_staging_table(&self, table: TableCatalog)

pub fn drop_staging_table(&self, name: &str)

pub fn staging_catalog_manager(&self) -> StagingCatalogManager

pub async fn check_cluster_limits(&self) -> Result<()>

Trait Implementations

impl Session for SessionImpl

async fn run_one_query( self: Arc<Self>, stmt: Statement, format: Format, ) -> Result<PgResponse<PgResponseStream>, BoxedError>

A copy of run_statement but exclude the parser part so each run must be at most one statement. The str sql use the to_string of AST. Consider Reuse later.

fn init_exec_context(&self, sql: Arc<str>) -> ExecContextGuard

Init and return an ExecContextGuard which could be used as a guard to represent the execution flow.

fn check_idle_in_transaction_timeout(&self) -> PsqlResult<()>

Check whether idle transaction timeout. If yes, unpin snapshot and return an IdleInTxnTimeout error.

type Portal = Portal

type PreparedStatement = PrepareStatement

type ValuesStream = PgResponseStream

fn user_authenticator(&self) -> &UserAuthenticator

fn id(&self) -> SessionId

async fn parse( self: Arc<Self>, statement: Option<Statement>, params_types: Vec<Option<DataType>>, ) -> Result<PrepareStatement, BoxedError>

fn bind( self: Arc<Self>, prepare_statement: PrepareStatement, params: Vec<Option<Bytes>>, param_formats: Vec<Format>, result_formats: Vec<Format>, ) -> Result<Portal, BoxedError>

async fn execute( self: Arc<Self>, portal: Portal, ) -> Result<PgResponse<PgResponseStream>, BoxedError>

fn describe_statement( self: Arc<Self>, prepare_statement: PrepareStatement, ) -> Result<(Vec<DataType>, Vec<PgFieldDescriptor>), BoxedError>

fn describe_portal( self: Arc<Self>, portal: Portal, ) -> Result<Vec<PgFieldDescriptor>, BoxedError>

fn get_config(&self, key: &str) -> Result<String, BoxedError>

fn set_config(&self, key: &str, value: String) -> Result<String, BoxedError>

async fn next_notice(self: &Arc<Self>) -> String

Receive the next notice message to send to the client.

fn transaction_status(&self) -> TransactionStatus