Skip to main content
Version: v0.3.0

src/sydra/query/executor.zig

Purpose​

Wraps the operator pipeline with a cursor API suitable for HTTP/pgwire surfaces.

See also​

Definition index (public)​

pub const Value​

Alias:

  • value.Value from src/sydra/query/value.zig

pub const ExecuteError​

Alias:

  • operator.ExecuteError

pub const OperatorStats​

Alias:

  • operator.Operator.StatsSnapshot

pub const ExecutionStats​

Timing and counters set by exec.execute, including:

  • parse/validate/optimize/physical/pipeline timings (microseconds)
  • trace_id
  • rows_emitted, rows_scanned

Full field list:

  • parse_us, validate_us, optimize_us, physical_us, pipeline_us
  • trace_id: []const u8
  • rows_emitted: u64
  • rows_scanned: u64

pub const ExecutionCursor​

Fields:

  • allocator: std.mem.Allocator – allocator used for operator + optional arena cleanup
  • operator: *operator.Operator – root of the operator pipeline
  • columns: []const plan.ColumnInfo – output schema (from physical.nodeOutput(root))
  • arena: ?*std.heap.ArenaAllocator – optionally owned arena for AST/plan lifetime
  • stats: ExecutionStats – timings/counters; filled by exec.execute

Methods:

  • next() – returns the next row from the operator pipeline
  • deinit() – destroys the operator and (if present) frees the arena
  • collectOperatorStats(allocator) – returns a snapshot list from the pipeline

Ownership notes:

  • next() returns operator.Row values that are owned by the underlying operator; treat them as valid until the next next() call on the same cursor/operator.
  • collectOperatorStats returns an owned slice; callers must free it with the allocator they passed in.
  • If arena is non-null, it is owned by the cursor and is freed by deinit() (this is how exec.execute keeps AST/plan pointers alive for the cursor lifetime).
ExecutionCursor (excerpt)
pub const ExecutionCursor = struct {
    allocator: std.mem.Allocator,
    operator: *operator.Operator,
    columns: []const plan.ColumnInfo,
    arena: ?*std.heap.ArenaAllocator = null,
    stats: ExecutionStats = .{},

    pub fn next(self: *ExecutionCursor) ExecuteError!?operator.Row {
        return self.operator.next();
    }

    pub fn deinit(self: *ExecutionCursor) void {
        self.operator.destroy();
        if (self.arena) |arena_ptr| {
            arena_ptr.deinit();
            self.allocator.destroy(arena_ptr);
            self.arena = null;
        }
    }

    pub fn collectOperatorStats(self: *ExecutionCursor, allocator: std.mem.Allocator) ![]OperatorStats {
        var list = ManagedArrayList(OperatorStats).init(allocator);
        errdefer list.deinit();
        try self.operator.collectStats(&list);
        return try list.toOwnedSlice();
    }
};

pub const Executor​

Creates an ExecutionCursor from a physical plan:

  • Executor.init(allocator, engine, physical_plan)
  • run() → ExecutionCursor
  • deinit() – no-op (present for symmetry)

Fields:

  • allocator: std.mem.Allocator
  • engine: *Engine
  • plan: physical.PhysicalPlan

Behavior notes:

  • run() builds the operator pipeline (operator.buildPipeline) and sets columns from physical.nodeOutput(plan.root).
  • run() returns a cursor with arena = null and zeroed stats; the orchestration entrypoint (exec.execute) wraps this and fills the timing fields + attaches an arena.