Files
clawhdf5/crates/clawhdf5/tests/contiguous_read_interop.rs
T
osobhandClaude Opus 5.5 b086dc3c2b format: read a contiguous selection's runs merged across small gaps
gather_storage merged only runs that touch, so a strided selection of a
contiguous dataset over a Storage became one range (and one owned Vec) per
element: a stride-2 read of 32M f32 through File::open_storage made
16,777,232 read_at calls, took 2.0 s and peaked at 2.09 GB.

The selection is now walked twice. The first walk checks the runs and plans
spans: runs in increasing order at most 4 KiB apart (GATHER_GAP_BYTES) are
read as one span up to 8 MiB (GATHER_SPAN_BYTES; a longer run is split), so
nothing is stored per run. The spans are fetched in RAW_BATCH_BYTES batches
while the second walk copies each run out of its span. Same checks and
errors as before.

The same read is now 32 reads and 0.31 s (File::open: 0.08 s).
contiguous_read_interop: every h5py-checked selection is also read through
File::open_storage and must give libhdf5's bytes; a new test bounds the
range reads of strided, blocked, column and point selections (stride 2: at
most 1 data read; 563,200 before).

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
2026-09-26 18:34:31 -05:00

489 lines
17 KiB
Rust

//! Reads of contiguous datasets — full reads and hyperslab/point selections,
//! through every typed reader — checked against h5py/libhdf5 for every
//! integer and float width, both byte orders, ranks 1 to 4, and datasets
//! larger than the huge-page threshold (4 MiB) the read buffers use.
//!
//! h5py writes the file and, for each selection, reads it with libhdf5's own
//! hyperslab/point selection (`select_hyperslab` with stride and block,
//! `select_elements`) and saves the raw bytes it gets back; the byte-level
//! [`Dataset::read_selection`] must return exactly those bytes, and the typed
//! readers the same values. Skipped when python3 with h5py is unavailable,
//! unless `CLAWHDF5_REQUIRE_INTEROP=1`.
use std::path::Path;
use std::process::Command;
use std::sync::Arc;
use clawhdf5::File;
use clawhdf5_format::selection::Selection;
use clawhdf5_format::storage::CountingStorage;
fn python() -> String {
std::env::var("CLAWHDF5_PYTHON").unwrap_or_else(|_| "python3".to_string())
}
fn interop_required() -> bool {
std::env::var("CLAWHDF5_REQUIRE_INTEROP").is_ok_and(|v| v == "1")
}
fn python_available() -> bool {
Command::new(python())
.args(["-c", "import h5py, numpy"])
.output()
.map(|o| o.status.success())
.unwrap_or(false)
}
macro_rules! skip_if_no_python {
() => {
if !python_available() {
assert!(
!interop_required(),
"CLAWHDF5_REQUIRE_INTEROP=1 but python3 with h5py is not available"
);
eprintln!("SKIP: python3 with h5py not available");
return;
}
};
}
fn run_python(script: &str) {
let output = Command::new(python())
.args(["-c", script])
.output()
.expect("failed to run python");
assert!(
output.status.success(),
"python failed:\n{}",
String::from_utf8_lossy(&output.stderr)
);
}
/// numpy type codes, with the modulus of the value pattern: every value is an
/// integer exactly representable in the type and in every typed reader's
/// output (f16 is exact below 2048, f32 below 2^24).
const DTYPES: [(&str, i64, bool); 11] = [
("i1", 201, true),
("u1", 251, false),
("i2", 2039, true),
("u2", 2039, false),
("i4", 1_000_003, true),
("u4", 1_000_003, false),
("i8", 1_000_003, true),
("u8", 1_000_003, false),
("f2", 2039, true),
("f4", 1_000_003, true),
("f8", 1_000_003, true),
];
/// Value of element `i` of a dataset of type `code` (the same formula as the
/// Python side): a permutation-revealing pattern, centred on 0 when signed.
fn value(code: &str, i: u64) -> i64 {
let (_, m, signed) = DTYPES.iter().find(|d| d.0 == code).unwrap();
let v = ((i as i128 * 7919) % *m as i128) as i64;
if *signed { v - m / 2 } else { v }
}
const SHAPES: [&[u64]; 4] = [&[1000], &[37, 53], &[7, 11, 13], &[3, 5, 7, 9]];
/// Datasets past the 4 MiB huge-page threshold, as (type, shape).
const BIG: [(&str, [u64; 2]); 4] = [
("f4", [1100, 1024]),
("i4", [1100, 1024]),
("f8", [600, 1024]),
("i8", [600, 1024]),
];
fn datasets() -> Vec<(String, String, Vec<u64>)> {
let mut out = Vec::new();
for (code, _, _) in DTYPES {
for (tag, _) in [("le", '<'), ("be", '>')] {
for shape in SHAPES {
out.push((
format!("{code}{tag}_r{}", shape.len()),
code.to_string(),
shape.to_vec(),
));
}
}
}
for (code, shape) in BIG {
for tag in ["le", "be"] {
out.push((format!("{code}{tag}_big"), code.to_string(), shape.to_vec()));
}
}
out
}
fn write_file(path: &Path) {
let script = format!(
r#"
import h5py, numpy as np
M = {{'i1': 201, 'u1': 251, 'i2': 2039, 'u2': 2039, 'i4': 1000003, 'u4': 1000003,
'i8': 1000003, 'u8': 1000003, 'f2': 2039, 'f4': 1000003, 'f8': 1000003}}
def values(code, n):
v = (np.arange(n, dtype=np.int64) * 7919) % M[code]
if code[0] != 'u':
v -= M[code] // 2
return v
shapes = [(1000,), (37, 53), (7, 11, 13), (3, 5, 7, 9)]
big = [('f4', (1100, 1024)), ('i4', (1100, 1024)), ('f8', (600, 1024)), ('i8', (600, 1024))]
with h5py.File("{path}", "w") as f:
for code in M:
for tag, e in (('le', '<'), ('be', '>')):
for shape in shapes:
n = int(np.prod(shape))
f.create_dataset(f"{{code}}{{tag}}_r{{len(shape)}}",
data=values(code, n).astype(e + code).reshape(shape))
for code, shape in big:
for tag, e in (('le', '<'), ('be', '>')):
n = int(np.prod(shape))
f.create_dataset(f"{{code}}{{tag}}_big",
data=values(code, n).astype(e + code).reshape(shape))
"#,
path = path.display()
);
run_python(&script);
}
#[test]
fn full_reads_match_h5py_for_every_type_order_and_size() {
skip_if_no_python!();
let dir = tempfile::tempdir().unwrap();
let path = dir.path().join("contig.h5");
write_file(&path);
let file = File::open(&path).unwrap();
for (name, code, shape) in datasets() {
let ds = file.dataset(&name).unwrap();
assert!(ds.read_raw_ref().unwrap().is_some(), "{name} is contiguous");
let n: u64 = shape.iter().product();
let want: Vec<i64> = (0..n).map(|i| value(&code, i)).collect();
assert_eq!(
ds.read_f64().unwrap(),
want.iter().map(|&v| v as f64).collect::<Vec<_>>(),
"{name} read_f64"
);
assert_eq!(
ds.read_f32().unwrap(),
want.iter().map(|&v| v as f32).collect::<Vec<_>>(),
"{name} read_f32"
);
assert_eq!(ds.read_i64().unwrap(), want, "{name} read_i64");
assert_eq!(
ds.read_i32().unwrap(),
want.iter().map(|&v| v as i32).collect::<Vec<_>>(),
"{name} read_i32"
);
// libhdf5 saturates negative values to 0 when reading as unsigned.
assert_eq!(
ds.read_u64().unwrap(),
want.iter().map(|&v| v.max(0) as u64).collect::<Vec<_>>(),
"{name} read_u64"
);
}
}
struct Rng(u64);
impl Rng {
fn next(&mut self) -> u64 {
self.0 = self.0.wrapping_add(0x9E37_79B9_7F4A_7C15);
let mut z = self.0;
z = (z ^ (z >> 30)).wrapping_mul(0xBF58_476D_1CE4_E5B9);
z = (z ^ (z >> 27)).wrapping_mul(0x94D0_49BB_1331_11EB);
z ^ (z >> 31)
}
fn below(&mut self, n: u64) -> u64 {
self.next() % n.max(1)
}
}
/// A hyperslab from per-dimension `(start, stride, count, block)`.
fn slab(dims: &[(u64, u64, u64, u64)]) -> Selection {
Selection::Hyperslab {
start: dims.iter().map(|d| d.0).collect(),
stride: dims.iter().map(|d| d.1).collect(),
count: dims.iter().map(|d| d.2).collect(),
block: dims.iter().map(|d| d.3).collect(),
}
}
/// Selections of every shape the read paths distinguish, all valid for `dims`.
fn selections(rng: &mut Rng, dims: &[u64]) -> Vec<Selection> {
let mut out = Vec::new();
// Unit-stride box.
out.push(slab(
&dims
.iter()
.map(|&n| {
let c = 1 + rng.below(n);
(rng.below(n - c + 1), 1, c, 1)
})
.collect::<Vec<_>>(),
));
// Strided (block 1), blocked (stride > block), and adjacent blocks
// (stride == block, which reads like a box): (block, stride - block).
for (block, gap) in [(1, 1), (2, 1), (2, 0)] {
out.push(slab(
&dims
.iter()
.map(|&n| {
let b = (block + rng.below(2)).min(n);
let st = b + gap + rng.below(2) * gap;
let s = rng.below(n - b + 1);
let c = 1 + rng.below((n - s - b) / st + 1);
(s, st, c, b)
})
.collect::<Vec<_>>(),
));
}
// Whole inner rows (one run across rows), and the whole dataset.
let r0 = rng.below(dims[0]);
let mut rows = vec![(r0, 1, 1 + rng.below(dims[0] - r0), 1)];
rows.extend(dims[1..].iter().map(|&n| (0, 1, n, 1)));
out.push(slab(&rows));
out.push(slab(
&dims.iter().map(|&n| (0, 1, n, 1)).collect::<Vec<_>>(),
));
// One element.
out.push(slab(
&dims
.iter()
.map(|&n| (rng.below(n), 1, 1, 1))
.collect::<Vec<_>>(),
));
// Distinct points in no particular order.
let mut points: Vec<Vec<u64>> = Vec::new();
for _ in 0..1 + rng.below(15) {
let p: Vec<u64> = dims.iter().map(|&n| rng.below(n)).collect();
if !points.contains(&p) {
points.push(p);
}
}
out.push(Selection::Points(points));
out
}
fn join(v: &[u64]) -> String {
v.iter().map(u64::to_string).collect::<Vec<_>>().join(",")
}
/// One element of type `code`, given as its raw file-order bytes, as an
/// integer (every value in these files is one).
fn decode(code: &str, big_endian: bool, bytes: &[u8]) -> i64 {
let mut b = bytes.to_vec();
if big_endian {
b.reverse();
}
let mut w = [0u8; 8];
w[..b.len()].copy_from_slice(&b);
let u = u64::from_le_bytes(w);
match code {
"i1" => u as u8 as i8 as i64,
"i2" => u as u16 as i16 as i64,
"i4" => u as u32 as i32 as i64,
"i8" => u as i64,
"u1" | "u2" | "u4" | "u8" => u as i64,
"f2" => clawhdf5_format::float16::f16_bits_to_f32(u as u16) as i64,
"f4" => f32::from_bits(u as u32) as i64,
"f8" => f64::from_bits(u) as i64,
_ => unreachable!(),
}
}
#[test]
fn selection_reads_match_h5py_for_every_type_order_and_rank() {
skip_if_no_python!();
let dir = tempfile::tempdir().unwrap();
let path = dir.path().join("contig.h5");
write_file(&path);
let mut rng = Rng(2026);
let mut cases: Vec<(String, String, Selection)> = Vec::new();
for (name, code, shape) in datasets() {
for sel in selections(&mut rng, &shape) {
cases.push((name.clone(), code.clone(), sel));
}
// Empty: a zero count, and Selection::None.
let mut empty = shape.iter().map(|&n| (0, 1, n, 1)).collect::<Vec<_>>();
empty[shape.len() - 1].2 = 0;
cases.push((name.clone(), code.clone(), slab(&empty)));
cases.push((name, code, Selection::None));
}
let mut spec = String::new();
for (k, (name, _, sel)) in cases.iter().enumerate() {
let line = match sel {
Selection::Hyperslab { count, .. } if count.contains(&0) => "N".to_string(),
Selection::Hyperslab {
start,
stride,
count,
block,
} => format!(
"H {};{};{};{}",
join(start),
join(stride),
join(count),
join(block)
),
Selection::Points(points) => format!(
"P {}",
points.iter().map(|p| join(p)).collect::<Vec<_>>().join(";")
),
Selection::None => "N".to_string(),
Selection::All => unreachable!(),
};
spec.push_str(&format!("{k} {name} {line}\n"));
}
let spec_path = dir.path().join("cases.txt");
std::fs::write(&spec_path, spec).unwrap();
run_python(&format!(
r#"
import h5py, numpy as np
with h5py.File("{path}", "r") as f:
for line in open("{spec}"):
k, name, kind, *rest = line.split()
d = f[name]
space = d.id.get_space()
if kind == 'H':
start, stride, count, block = (tuple(int(x) for x in part.split(','))
for part in rest[0].split(';'))
space.select_hyperslab(start, count, stride, block)
elif kind == 'P':
pts = np.array([[int(x) for x in p.split(',')] for p in rest[0].split(';')],
dtype=np.uint64)
space.select_elements(pts)
else:
space.select_none()
n = space.get_select_npoints()
out = np.empty(n, dtype=d.dtype)
if n:
d.id.read(h5py.h5s.create_simple((n,)), space, out)
open("{dir}/sel_" + k + ".bin", "wb").write(out.tobytes())
"#,
path = path.display(),
spec = spec_path.display(),
dir = dir.path().display(),
));
let file = File::open(&path).unwrap();
// The same file over a storage that serves only range reads: the
// selections read only their runs (see `strided_selections_over_storage_
// read_few_ranges`) and must give the same bytes.
let remote = File::open_storage(Arc::new(CountingStorage::new(
std::fs::read(&path).unwrap(),
)))
.unwrap();
for (k, (name, code, sel)) in cases.iter().enumerate() {
let ds = file.dataset(name).unwrap();
let want_bytes = std::fs::read(dir.path().join(format!("sel_{k}.bin"))).unwrap();
let rds = remote.dataset(name).unwrap();
assert!(
rds.read_selection(sel).unwrap() == want_bytes,
"{name} {sel:?}: bytes over a range storage differ from libhdf5's"
);
assert_eq!(
rds.read_f64_selection(sel).unwrap(),
ds.read_f64_selection(sel).unwrap(),
"{name} {sel:?}: f64 over a range storage"
);
assert_eq!(
rds.read_i32_selection(sel).unwrap(),
ds.read_i32_selection(sel).unwrap(),
"{name} {sel:?}: i32 over a range storage"
);
let got_bytes = ds.read_selection(sel).unwrap();
assert!(
got_bytes == want_bytes,
"{name} {sel:?}: raw bytes differ from libhdf5's ({} vs {} bytes)",
got_bytes.len(),
want_bytes.len()
);
let size = ds.raw_datatype().unwrap().type_size() as usize;
let want: Vec<i64> = want_bytes
.chunks_exact(size)
.map(|e| decode(code, name.contains("be_"), e))
.collect();
assert_eq!(
ds.read_f64_selection(sel).unwrap(),
want.iter().map(|&v| v as f64).collect::<Vec<_>>(),
"{name} {sel:?} as f64"
);
assert_eq!(
ds.read_f32_selection(sel).unwrap(),
want.iter().map(|&v| v as f32).collect::<Vec<_>>(),
"{name} {sel:?} as f32"
);
assert_eq!(
ds.read_i64_selection(sel).unwrap(),
want,
"{name} {sel:?} as i64"
);
assert_eq!(
ds.read_i32_selection(sel).unwrap(),
want.iter().map(|&v| v as i32).collect::<Vec<_>>(),
"{name} {sel:?} as i32"
);
}
}
/// Over a storage without the file in memory, a selection of a contiguous
/// dataset reads its runs merged across small gaps: a strided selection is
/// a few large reads, not one per element (563 200 for the stride-2 case
/// before), and the values are libhdf5's.
#[test]
fn strided_selections_over_storage_read_few_ranges() {
skip_if_no_python!();
let dir = tempfile::tempdir().unwrap();
let path = dir.path().join("contig.h5");
write_file(&path);
let storage = Arc::new(CountingStorage::new(std::fs::read(&path).unwrap()));
let remote = File::open_storage(storage.clone()).unwrap();
let local = File::open(&path).unwrap();
// f4le_big is 1100 x 1024 f32: 4 KiB rows, 4.4 MB in all.
let name = "f4le_big";
let every_100th: Vec<Vec<u64>> = (0..1100u64 * 1024)
.step_by(100)
.map(|i| vec![i / 1024, i % 1024])
.collect();
let backwards: Vec<Vec<u64>> = every_100th.iter().rev().take(50).cloned().collect();
// (selection, most range reads it may take)
let cases: Vec<(Selection, u64)> = vec![
// Every other element of every row: one read of the whole dataset.
(slab(&[(0, 1, 1100, 1), (0, 2, 512, 1)]), 1),
// Blocks of 3 every 7 on every other row: rows are 4 KiB apart, so
// one read per selected row at most.
(slab(&[(0, 2, 550, 1), (1, 7, 146, 3)]), 550),
// Every 100th element, in order: 400-byte gaps, one read.
(Selection::Points(every_100th), 1),
// Points going backwards are not merged.
(Selection::Points(backwards), 50),
// A column: 4 KiB apart, merged.
(slab(&[(0, 1, 1100, 1), (5, 1, 1, 1)]), 1),
];
let ds = remote.dataset(name).unwrap();
for (sel, most) in cases {
storage.reset();
let got = ds.read_f32_selection(&sel).unwrap();
let reads = storage.reads();
assert_eq!(
got,
local
.dataset(name)
.unwrap()
.read_f32_selection(&sel)
.unwrap(),
"{sel:?}"
);
// A few reads of metadata besides the data.
assert!(reads <= most + 8, "{sel:?}: {reads} range reads");
storage.reset();
let bytes = ds.read_selection(&sel).unwrap();
assert!(
storage.reads() <= most + 8,
"{sel:?}: {} reads",
storage.reads()
);
assert_eq!(bytes.len(), got.len() * 4);
}
}