ruvector-postgres 2.0.5

//! PostgreSQL hooks for query interception

use pgrx::prelude::*;
use super::state::{DAG_STATE, TRAJECTORY_BUFFER, TrajectoryEntry};
use super::guc;

/// Hook into planner to analyze query DAG
pub fn planner_hook(
    parse: *mut pg_sys::Query,
    query_string: *const std::os::raw::c_char,
    cursor_options: std::os::raw::c_int,
    bound_params: *mut pg_sys::ParamListInfoData,
) -> *mut pg_sys::PlannedStmt {
    // Call original planner first
    let result = unsafe {
        // Call previous hook or standard planner
        pg_sys::standard_planner(parse, query_string, cursor_options, bound_params)
    };

    if !guc::is_enabled() {
        return result;
    }

    // Analyze the plan and extract DAG
    // This is where we'd convert PlannedStmt to our QueryDag

    result
}

/// Hook at executor start to record trajectory start
pub fn executor_start_hook(
    query_desc: *mut pg_sys::QueryDesc,
    eflags: std::os::raw::c_int,
) {
    if !guc::is_enabled() {
        return;
    }

    // Compute query hash
    let query_hash = compute_query_hash(query_desc);

    // Record trajectory start
    TRAJECTORY_BUFFER.insert(query_hash, TrajectoryEntry {
        query_hash,
        start_time: std::time::Instant::now(),
        dag_structure: None,
    });
}

/// Hook at executor end to record trajectory completion
pub fn executor_end_hook(query_desc: *mut pg_sys::QueryDesc) {
    if !guc::is_enabled() {
        return;
    }

    let query_hash = compute_query_hash(query_desc);

    if let Some((_, entry)) = TRAJECTORY_BUFFER.remove(&query_hash) {
        let execution_time = entry.start_time.elapsed();

        // Record trajectory for learning
        DAG_STATE.increment_trajectories();

        // TODO: Send to SONA engine for learning
    }
}

fn compute_query_hash(query_desc: *mut pg_sys::QueryDesc) -> u64 {
    // Compute deterministic hash from query
    use std::hash::{Hash, Hasher};
    use std::collections::hash_map::DefaultHasher;

    let mut hasher = DefaultHasher::new();
    // Hash relevant query properties
    0u64.hash(&mut hasher);
    hasher.finish()
}