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Add validity fast-path helper for the four pattern-matching encoders #7995

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Add validity fast-path helper for the four pattern-matching encoders #7995

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171 changes: 121 additions & 50 deletions vortex-row/src/codec.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,7 @@ use vortex_array::dtype::NativePType;
use vortex_array::dtype::PType;
use vortex_array::dtype::half::f16;
use vortex_array::match_each_native_ptype;
use vortex_array::validity::Validity;
use vortex_buffer::ByteBufferMut;
use vortex_error::VortexResult;
use vortex_error::vortex_bail;
Expand Down Expand Up @@ -77,6 +78,33 @@ const fn encoded_size_for_fixed(value_bytes: u32) -> u32 {
1 + value_bytes
}

/// Pre-resolved per-row validity for the row encoders.
///
/// Encoders pattern-match on this once before their inner loop so the
/// no-nulls fast path avoids per-row `mask.value(i)` branches entirely,
/// and the nullable path holds the materialized mask exactly once.
pub(crate) enum ValidityKind {
/// Column statically has no nulls (`Validity::NonNullable` or `AllValid`); no mask
/// allocation needed.
AllValid,
/// Column may have nulls; the materialized per-row mask is included.
Mask(vortex_mask::Mask),
}

/// Resolve a [`Validity`] into a [`ValidityKind`], materializing the mask only when
/// the column may actually have nulls.
#[inline]
pub(crate) fn resolve_validity(
validity: Validity,
len: usize,
ctx: &mut ExecutionCtx,
) -> VortexResult<ValidityKind> {
Ok(match validity {
Validity::NonNullable | Validity::AllValid => ValidityKind::AllValid,
other => ValidityKind::Mask(other.execute_mask(len, ctx)?),
})
}

/// Per-row width classification for a column.
///
/// `Fixed(w)` means every row encodes to exactly `w` bytes (sentinel + value), regardless
Expand Down Expand Up @@ -245,15 +273,21 @@ fn add_size_varbinview(
sizes: &mut [u32],
ctx: &mut ExecutionCtx,
) -> VortexResult<()> {
let mask = arr.as_ref().validity()?.execute_mask(arr.len(), ctx)?;
let views = arr.views();
for (i, view) in views.iter().enumerate() {
let valid = mask.value(i);
if !valid {
sizes[i] += 1; // sentinel only
} else {
let len = view.len() as usize;
sizes[i] += encoded_size_for_varlen(len);
match resolve_validity(arr.as_ref().validity()?, arr.len(), ctx)? {
ValidityKind::AllValid => {
for (i, view) in views.iter().enumerate() {
sizes[i] += encoded_size_for_varlen(view.len() as usize);
}
}
ValidityKind::Mask(mask) => {
for (i, view) in views.iter().enumerate() {
if mask.value(i) {
sizes[i] += encoded_size_for_varlen(view.len() as usize);
} else {
sizes[i] += 1; // sentinel only
}
}
}
}
Ok(())
Expand Down Expand Up @@ -336,23 +370,35 @@ fn encode_bool(
out: &mut [u8],
ctx: &mut ExecutionCtx,
) -> VortexResult<()> {
let mask = arr.as_ref().validity()?.execute_mask(arr.len(), ctx)?;
let bits = arr.clone().into_bit_buffer();
let non_null = field.non_null_sentinel();
let null = field.null_sentinel();
let xor = if field.descending { 0xFF } else { 0x00 };
for i in 0..bits.len() {
let pos = (row_offsets[i] + col_offset[i]) as usize;
if mask.value(i) {
out[pos] = non_null;
// false=0x01, true=0x02 so false < true; XOR for descending
let raw = if bits.value(i) { 0x02u8 } else { 0x01u8 };
out[pos + 1] = raw ^ xor;
} else {
out[pos] = null;
out[pos + 1] = 0;
match resolve_validity(arr.as_ref().validity()?, arr.len(), ctx)? {
ValidityKind::AllValid => {
for i in 0..bits.len() {
let pos = (row_offsets[i] + col_offset[i]) as usize;
out[pos] = non_null;
let raw = if bits.value(i) { 0x02u8 } else { 0x01u8 };
out[pos + 1] = raw ^ xor;
col_offset[i] += BOOL_ENCODED_SIZE;
}
}
ValidityKind::Mask(mask) => {
let null = field.null_sentinel();
for i in 0..bits.len() {
let pos = (row_offsets[i] + col_offset[i]) as usize;
if mask.value(i) {
out[pos] = non_null;
// false=0x01, true=0x02 so false < true; XOR for descending
let raw = if bits.value(i) { 0x02u8 } else { 0x01u8 };
out[pos + 1] = raw ^ xor;
} else {
out[pos] = null;
out[pos + 1] = 0;
}
col_offset[i] += BOOL_ENCODED_SIZE;
}
}
col_offset[i] += BOOL_ENCODED_SIZE;
}
Ok(())
}
Expand All @@ -379,24 +425,35 @@ fn encode_primitive_typed<T: NativePType + RowEncode>(
out: &mut [u8],
ctx: &mut ExecutionCtx,
) -> VortexResult<()> {
let mask = arr.as_ref().validity()?.execute_mask(arr.len(), ctx)?;
let slice: &[T] = arr.as_slice();
let non_null = field.non_null_sentinel();
let null = field.null_sentinel();
let value_bytes = size_of::<T>();
for (i, &v) in slice.iter().enumerate() {
let pos = (row_offsets[i] + col_offset[i]) as usize;
if mask.value(i) {
out[pos] = non_null;
v.encode_to(&mut out[pos + 1..pos + 1 + value_bytes], field.descending);
} else {
out[pos] = null;
// Zero-fill the value bytes.
for b in &mut out[pos + 1..pos + 1 + value_bytes] {
*b = 0;
let stride = encoded_size_for_fixed(value_bytes as u32);
match resolve_validity(arr.as_ref().validity()?, arr.len(), ctx)? {
ValidityKind::AllValid => {
for (i, &v) in slice.iter().enumerate() {
let pos = (row_offsets[i] + col_offset[i]) as usize;
out[pos] = non_null;
v.encode_to(&mut out[pos + 1..pos + 1 + value_bytes], field.descending);
col_offset[i] += stride;
}
}
ValidityKind::Mask(mask) => {
let null = field.null_sentinel();
for (i, &v) in slice.iter().enumerate() {
let pos = (row_offsets[i] + col_offset[i]) as usize;
if mask.value(i) {
out[pos] = non_null;
v.encode_to(&mut out[pos + 1..pos + 1 + value_bytes], field.descending);
} else {
out[pos] = null;
for b in &mut out[pos + 1..pos + 1 + value_bytes] {
*b = 0;
}
}
col_offset[i] += stride;
}
}
col_offset[i] += encoded_size_for_fixed(value_bytes as u32);
}
Ok(())
}
Expand Down Expand Up @@ -471,24 +528,38 @@ fn encode_varbinview(
out: &mut [u8],
ctx: &mut ExecutionCtx,
) -> VortexResult<()> {
let mask = arr.as_ref().validity()?.execute_mask(arr.len(), ctx)?;
let non_null = field.non_null_sentinel();
let null = field.null_sentinel();

arr.with_iterator(|iter| {
for (i, maybe) in iter.enumerate() {
let pos = (row_offsets[i] + col_offset[i]) as usize;
if !mask.value(i) {
out[pos] = null;
col_offset[i] += 1;
continue;
}
let bytes: &[u8] = maybe.unwrap_or(&[]);
out[pos] = non_null;
let written = encode_varlen_value(bytes, &mut out[pos + 1..], field.descending);
col_offset[i] += 1 + written;
let descending = field.descending;
match resolve_validity(arr.as_ref().validity()?, arr.len(), ctx)? {
ValidityKind::AllValid => {
arr.with_iterator(|iter| {
for (i, maybe) in iter.enumerate() {
let pos = (row_offsets[i] + col_offset[i]) as usize;
let bytes: &[u8] = maybe.unwrap_or(&[]);
out[pos] = non_null;
let written = encode_varlen_value(bytes, &mut out[pos + 1..], descending);
col_offset[i] += 1 + written;
}
});
}
});
ValidityKind::Mask(mask) => {
let null = field.null_sentinel();
arr.with_iterator(|iter| {
for (i, maybe) in iter.enumerate() {
let pos = (row_offsets[i] + col_offset[i]) as usize;
if !mask.value(i) {
out[pos] = null;
col_offset[i] += 1;
continue;
}
let bytes: &[u8] = maybe.unwrap_or(&[]);
out[pos] = non_null;
let written = encode_varlen_value(bytes, &mut out[pos + 1..], descending);
col_offset[i] += 1 + written;
}
});
}
}
Ok(())
}

Expand Down
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