Struct StatementLoggingFrontend

pub struct StatementLoggingFrontend {
    pub throttling_state: Arc<ThrottlingState>,
    pub reproducible_rng: Arc<Mutex<ChaCha8Rng>>,
    pub build_info_human_version: String,
    pub now: NowFn,
}

Encapsulates statement logging state needed by the frontend peek sequencing.

This struct bundles together all the statement logging-related state that the frontend peek sequencing needs to perform statement logging independently of the Coordinator’s main task.

Fields

throttling_state: Arc<ThrottlingState>

Shared throttling state for rate-limiting statement logging.

reproducible_rng: Arc<Mutex<ChaCha8Rng>>

Reproducible RNG for statement sampling (only used in tests).

build_info_human_version: String

Cached human version string from build info.

now: NowFn

Function to get current time for statement logging.

Implementations

impl StatementLoggingFrontend

fn get_prepared_statement_info( &self, session: &mut Session, logging: &Arc<QCell<PreparedStatementLoggingInfo>>, ) -> (Option<PreparedStatementEvent>, Uuid)

Get prepared statement info for frontend peek sequencing.

This function processes prepared statement logging info and builds the event rows. It does NOT do throttling - that is handled externally by the caller in begin_statement_execution. It DOES mutate the logging info to mark the statement as already logged.

Arguments

• session - The session executing the statement
• logging - Prepared statement logging info

Returns

A tuple containing:

• Option<PreparedStatementEvent>: If the prepared statement has not yet been logged, returns the packed rows for the prepared statement.
• Uuid: The UUID of the prepared statement.

pub fn begin_statement_execution( &self, session: &mut Session, params: &Params, logging: &Arc<QCell<PreparedStatementLoggingInfo>>, system_config: &SystemVars, lifecycle_timestamps: Option<LifecycleTimestamps>, ) -> Option<(StatementLoggingId, StatementBeganExecutionRecord, Row, Option<PreparedStatementEvent>)>

Begin statement execution logging from the frontend. (Corresponds to Coordinator::begin_statement_execution, which is used by the old peek sequencing.)

This encapsulates all the statement logging setup:

• Retrieves system config values
• Performs sampling and throttling checks
• Creates statement logging records
• Attends to metrics.

Returns None if the statement should not be logged (due to sampling or throttling), or the info required to proceed with statement logging. The Row is the pre-packed row for mz_statement_execution_history. The Option<PreparedStatementEvent> is None when we have already logged the prepared statement before, and this is just a subsequent execution.

Trait Implementations

impl Clone for StatementLoggingFrontend

fn clone(&self) -> StatementLoggingFrontend

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for StatementLoggingFrontend

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.