Struct SizeGuards 

pub struct SizeGuards {
    pub max_cell_bytes: usize,
    pub max_row_bytes: usize,
    pub max_total_buffered_bytes: usize,
}

Per-connection size ceilings applied to every read.

All three caps are byte counts; 0 disables that dimension. The defaults are generous enough that ordinary OLTP rows never trip them yet still cap a runaway result well short of an OOM:

• max_cell_bytes (default 64 MiB) — a single value’s payload.
• max_row_bytes (default 256 MiB) — one row’s summed cell payloads.
• max_total_buffered_bytes (default 1 GiB) — the running total an eager query is allowed to materialize before failing with SqlError::BufferTooLarge. The streaming cursor does not apply this total (it never buffers the whole result); it applies only the per-cell and per-row caps.

Construct with SizeGuards::unlimited to opt out entirely, or tweak individual fields. The guards are copied into each connection at connect time and consulted on every row.

Fields

max_cell_bytes: usize

Max payload bytes for a single cell; 0 = unlimited.

max_row_bytes: usize

Max summed payload bytes for one row; 0 = unlimited.

max_total_buffered_bytes: usize

Max running total an eager query may buffer; 0 = unlimited. Ignored by the streaming cursor, which is bounded by design.

Implementations

impl SizeGuards

pub fn unlimited() -> Self

Disable every guard. Use only when the caller has its own bound on result size and wants ferrule-sql to impose none.

pub fn check_row( &self, row_ordinal: u64, row: &[Value], columns: &[ColumnInfo], ) -> Result<(), SqlError>

Check one fully-decoded row against the per-cell and per-row caps. Returns a structured SqlError naming the offending row/column the instant a cap is crossed, so the caller never retains an over-budget row.

row_ordinal is the 0-based position of this row within the current result (used only for diagnostics). columns supplies the column names for the SqlError::CellTooLarge message; when shorter than the row (or empty) the column index is rendered instead. This performs no allocation proportional to row size — it sums precomputed Value::byte_size values.

pub fn caps_total(&self) -> bool

True when this configuration buffers an eager result under a finite total cap. The eager query path uses this to decide whether to maintain the running byte tally at all.

Trait Implementations

impl Clone for SizeGuards

fn clone(&self) -> SizeGuards

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for SizeGuards

impl Debug for SizeGuards

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

Formats the value using the given formatter.

impl Default for SizeGuards

fn default() -> Self

Returns the “default value” for a type.

impl Eq for SizeGuards

impl PartialEq for SizeGuards

fn eq(&self, other: &SizeGuards) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for SizeGuards