|
| 1 | +#!/usr/bin/env python3 |
| 2 | +""" |
| 3 | +Convert pre-downloaded MSMARCO v2.1 parquet parts into raw shard files (FIXED). |
| 4 | +
|
| 5 | +Key properties: |
| 6 | +- Batched Arrow → NumPy iteration (no per-row Python objects) |
| 7 | +- Vectorized cosine normalization |
| 8 | +- Flat, predictable RSS usage |
| 9 | +- Optional O_DSYNC writes (--direct) |
| 10 | +
|
| 11 | +To download the parquet parts first: |
| 12 | +
|
| 13 | +``` |
| 14 | +HF_HOME=/mnt/ssd2/hf_cache |
| 15 | +mkdir -p "$HF_HOME" |
| 16 | +
|
| 17 | +from datasets import load_dataset |
| 18 | +load_dataset( |
| 19 | + "Cohere/msmarco-v2.1-embed-english-v3", |
| 20 | + "passages", |
| 21 | + split="train", |
| 22 | + streaming=False, |
| 23 | + cache_dir="$HF_HOME") |
| 24 | +``` |
| 25 | +
|
| 26 | +Usage: |
| 27 | + HF_HOME=/path/to/hf_cache \ |
| 28 | + python convert-msmarco-parquet-to-shards.py \ |
| 29 | + --parquet-glob "$HF_HOME/datasets/Cohere___msmarco-v2.1-embed-english-v3/passages_parquet/*.parquet" \ |
| 30 | + --out-dir datasets \ |
| 31 | + --count 10_000_000 \ |
| 32 | + --shard-size 100000 \ |
| 33 | + --batch-rows 8192 \ |
| 34 | + --fsync-every 50000 \ |
| 35 | + --direct |
| 36 | +""" |
| 37 | + |
| 38 | +from __future__ import annotations |
| 39 | + |
| 40 | +import argparse |
| 41 | +import glob |
| 42 | +import heapq |
| 43 | +import json |
| 44 | +import mmap |
| 45 | +import os |
| 46 | +import time |
| 47 | +from pathlib import Path |
| 48 | + |
| 49 | +import numpy as np |
| 50 | +import pyarrow.parquet as pq |
| 51 | + |
| 52 | +# ---------------- constants ---------------- |
| 53 | + |
| 54 | +TOPK = 50 |
| 55 | +Q_COUNT = 1000 |
| 56 | +CHUNK = 4096 |
| 57 | +PROGRESS_EVERY = 100_000 |
| 58 | + |
| 59 | +# ---------------- helpers ---------------- |
| 60 | + |
| 61 | + |
| 62 | +def fmt_secs(secs: float | None) -> str: |
| 63 | + if secs is None or secs <= 0: |
| 64 | + return "?" |
| 65 | + m, s = divmod(int(secs + 0.5), 60) |
| 66 | + h, m = divmod(m, 60) |
| 67 | + return f"{h:d}:{m:02d}:{s:02d}" if h else f"{m:02d}:{s:02d}" |
| 68 | + |
| 69 | + |
| 70 | +def sync_and_advise(fd: int) -> None: |
| 71 | + try: |
| 72 | + os.fsync(fd) |
| 73 | + except OSError: |
| 74 | + pass |
| 75 | + try: |
| 76 | + os.posix_fadvise(fd, 0, 0, os.POSIX_FADV_DONTNEED) |
| 77 | + except (AttributeError, OSError): |
| 78 | + pass |
| 79 | + |
| 80 | + |
| 81 | +def close_memmap(mm: np.memmap | None) -> None: |
| 82 | + if mm is None: |
| 83 | + return |
| 84 | + mm.flush() |
| 85 | + m = getattr(mm, "_mmap", None) |
| 86 | + if m is not None: |
| 87 | + try: |
| 88 | + m.madvise(mmap.MADV_DONTNEED) |
| 89 | + except Exception: |
| 90 | + pass |
| 91 | + m.close() |
| 92 | + |
| 93 | + |
| 94 | +# ---------------- writer ---------------- |
| 95 | + |
| 96 | + |
| 97 | +class DirectWriter: |
| 98 | + def __init__(self, path: Path, direct: bool): |
| 99 | + flags = os.O_WRONLY | os.O_CREAT | os.O_TRUNC |
| 100 | + if direct and hasattr(os, "O_DSYNC"): |
| 101 | + flags |= os.O_DSYNC |
| 102 | + self.fd = os.open(path, flags, 0o644) |
| 103 | + |
| 104 | + def write(self, b: bytes) -> None: |
| 105 | + mv = memoryview(b) |
| 106 | + off = 0 |
| 107 | + while off < len(mv): |
| 108 | + n = os.write(self.fd, mv[off:]) |
| 109 | + if n == 0: |
| 110 | + raise OSError("write returned 0") |
| 111 | + off += n |
| 112 | + |
| 113 | + def fileno(self) -> int: |
| 114 | + return self.fd |
| 115 | + |
| 116 | + def close(self) -> None: |
| 117 | + os.close(self.fd) |
| 118 | + |
| 119 | + |
| 120 | +def open_writer(path: Path, direct: bool): |
| 121 | + if direct: |
| 122 | + return DirectWriter(path, direct=True) |
| 123 | + return open(path, "wb", buffering=1 << 20) |
| 124 | + |
| 125 | + |
| 126 | +# ---------------- GT computation ---------------- |
| 127 | + |
| 128 | + |
| 129 | +def build_gt_sharded( |
| 130 | + shards: list[dict], |
| 131 | + total_count: int, |
| 132 | + dim: int, |
| 133 | + gt_path: Path, |
| 134 | + q_count: int, |
| 135 | + topk: int, |
| 136 | +): |
| 137 | + print(f"[GT] building exact GT for {q_count} queries, k={topk}") |
| 138 | + |
| 139 | + q_count = min(q_count, total_count) |
| 140 | + rng = np.random.default_rng() |
| 141 | + q_indices = rng.choice(total_count, size=q_count, replace=False) |
| 142 | + |
| 143 | + # Load query vectors |
| 144 | + queries = np.empty((q_count, dim), dtype=np.float32) |
| 145 | + shard_map = {} |
| 146 | + |
| 147 | + for qi, gidx in enumerate(q_indices): |
| 148 | + for s in shards: |
| 149 | + if s["start"] <= gidx < s["start"] + s["count"]: |
| 150 | + shard_map.setdefault(s["path"], []).append((qi, gidx - s["start"])) |
| 151 | + break |
| 152 | + |
| 153 | + for s in shards: |
| 154 | + assigns = shard_map.get(s["path"]) |
| 155 | + if not assigns: |
| 156 | + continue |
| 157 | + mm = np.memmap(s["path"], dtype=np.float32, mode="r", shape=(s["count"], dim)) |
| 158 | + for qi, li in assigns: |
| 159 | + queries[qi] = mm[li] |
| 160 | + close_memmap(mm) |
| 161 | + |
| 162 | + # Top-k heaps |
| 163 | + heaps = [[] for _ in range(q_count)] |
| 164 | + |
| 165 | + for s in shards: |
| 166 | + print(f"[GT] scanning {s['path'].name}") |
| 167 | + mm = np.memmap(s["path"], dtype=np.float32, mode="r", shape=(s["count"], dim)) |
| 168 | + for off in range(0, s["count"], CHUNK): |
| 169 | + block = mm[off : off + CHUNK] |
| 170 | + sims = block @ queries.T |
| 171 | + for qi in range(q_count): |
| 172 | + heap = heaps[qi] |
| 173 | + col = sims[:, qi] |
| 174 | + for i, score in enumerate(col): |
| 175 | + doc_id = s["start"] + off + i |
| 176 | + if len(heap) < topk: |
| 177 | + heapq.heappush(heap, (score, doc_id)) |
| 178 | + else: |
| 179 | + heapq.heappushpop(heap, (score, doc_id)) |
| 180 | + close_memmap(mm) |
| 181 | + |
| 182 | + with open(gt_path, "w") as f: |
| 183 | + for qi, heap in enumerate(heaps): |
| 184 | + heap.sort(reverse=True) |
| 185 | + json.dump( |
| 186 | + { |
| 187 | + "query_id": int(q_indices[qi]), |
| 188 | + "topk": [{"doc_id": int(d), "score": float(s)} for s, d in heap], |
| 189 | + }, |
| 190 | + f, |
| 191 | + ) |
| 192 | + f.write("\n") |
| 193 | + |
| 194 | + print(f"[GT] wrote {gt_path}") |
| 195 | + |
| 196 | + |
| 197 | +# ---------------- main ---------------- |
| 198 | + |
| 199 | + |
| 200 | +def main(): |
| 201 | + ap = argparse.ArgumentParser() |
| 202 | + ap.add_argument("--parquet-glob", required=True) |
| 203 | + ap.add_argument("--out-dir", default="datasets") |
| 204 | + ap.add_argument("--count", default="1_000_000") |
| 205 | + ap.add_argument("--shard-size", type=int, default=100_000) |
| 206 | + ap.add_argument("--batch-rows", type=int, default=8192) |
| 207 | + ap.add_argument("--fsync-every", type=int, default=50_000) |
| 208 | + ap.add_argument("--direct", action="store_true") |
| 209 | + args = ap.parse_args() |
| 210 | + |
| 211 | + count = int(str(args.count).replace("_", "")) |
| 212 | + shard_size = args.shard_size |
| 213 | + |
| 214 | + parquet_files = sorted(glob.glob(args.parquet_glob)) |
| 215 | + if not parquet_files: |
| 216 | + raise SystemExit("No parquet files found") |
| 217 | + |
| 218 | + out_dir = Path(args.out_dir) |
| 219 | + out_dir.mkdir(parents=True, exist_ok=True) |
| 220 | + |
| 221 | + print(f"[init] Found {len(parquet_files)} parquet files to process") |
| 222 | + |
| 223 | + dim = None |
| 224 | + written = 0 |
| 225 | + filled = 0 |
| 226 | + shard_idx = 0 |
| 227 | + shard_start = 0 |
| 228 | + shards = [] |
| 229 | + |
| 230 | + writer = None |
| 231 | + path = None |
| 232 | + |
| 233 | + t0 = time.time() |
| 234 | + last_report = 0 |
| 235 | + |
| 236 | + # Process files one at a time; use ParquetFile iter_batches to avoid list offset overflow in datasets |
| 237 | + for file_idx, parquet_file in enumerate(parquet_files): |
| 238 | + if written >= count: |
| 239 | + break |
| 240 | + |
| 241 | + print( |
| 242 | + f"[process] File {file_idx + 1}/{len(parquet_files)}: {Path(parquet_file).name}" |
| 243 | + ) |
| 244 | + |
| 245 | + pf = pq.ParquetFile(parquet_file) |
| 246 | + |
| 247 | + for record_batch in pf.iter_batches( |
| 248 | + columns=["emb"], batch_size=args.batch_rows |
| 249 | + ): |
| 250 | + col = record_batch.column(0) # ListArray |
| 251 | + offsets = col.offsets.to_numpy() |
| 252 | + values = np.asarray( |
| 253 | + col.values.to_numpy(zero_copy_only=False), dtype=np.float32 |
| 254 | + ) |
| 255 | + |
| 256 | + # Infer dimension from first batch if unknown |
| 257 | + if dim is None: |
| 258 | + dim = int(offsets[1] - offsets[0]) |
| 259 | + path = out_dir / f"msmarco-passages-{count}.shard{shard_idx:04d}.f32" |
| 260 | + writer = open_writer(path, args.direct) |
| 261 | + |
| 262 | + # Validate fixed-size lists |
| 263 | + spans = offsets[1:] - offsets[:-1] |
| 264 | + if not np.all(spans == dim): |
| 265 | + raise RuntimeError( |
| 266 | + f"Non-uniform embedding dimension detected in {parquet_file}" |
| 267 | + ) |
| 268 | + |
| 269 | + # Ensure a writable, contiguous float32 view before normalization |
| 270 | + embs = np.asarray(values, dtype=np.float32).reshape(-1, dim) |
| 271 | + embs = embs / (np.linalg.norm(embs, axis=1, keepdims=True) + 1e-12) |
| 272 | + embs = np.ascontiguousarray(embs) |
| 273 | + |
| 274 | + off = 0 |
| 275 | + while off < len(embs) and written < count: |
| 276 | + take = min(shard_size - filled, count - written, len(embs) - off) |
| 277 | + writer.write(embs[off : off + take].tobytes(order="C")) |
| 278 | + off += take |
| 279 | + filled += take |
| 280 | + written += take |
| 281 | + |
| 282 | + if written % args.fsync_every == 0: |
| 283 | + sync_and_advise(writer.fileno()) |
| 284 | + |
| 285 | + if filled == shard_size and written < count: |
| 286 | + sync_and_advise(writer.fileno()) |
| 287 | + writer.close() |
| 288 | + shards.append({"path": path, "count": filled, "start": shard_start}) |
| 289 | + shard_start += filled |
| 290 | + shard_idx += 1 |
| 291 | + filled = 0 |
| 292 | + path = ( |
| 293 | + out_dir / f"msmarco-passages-{count}.shard{shard_idx:04d}.f32" |
| 294 | + ) |
| 295 | + writer = open_writer(path, args.direct) |
| 296 | + |
| 297 | + if written - last_report >= PROGRESS_EVERY: |
| 298 | + elapsed = time.time() - t0 |
| 299 | + rate = written / elapsed |
| 300 | + eta = (count - written) / rate if rate else None |
| 301 | + print( |
| 302 | + f"[convert] {written:,}/{count:,} | {rate:,.0f} v/s | eta {fmt_secs(eta)}" |
| 303 | + ) |
| 304 | + last_report = written |
| 305 | + |
| 306 | + if written >= count: |
| 307 | + break |
| 308 | + |
| 309 | + if writer is not None: |
| 310 | + sync_and_advise(writer.fileno()) |
| 311 | + writer.close() |
| 312 | + if filled > 0: |
| 313 | + shards.append({"path": path, "count": filled, "start": shard_start}) |
| 314 | + |
| 315 | + meta = { |
| 316 | + "dim": dim, |
| 317 | + "dtype": "float32", |
| 318 | + "count": written, |
| 319 | + "shard_size": shard_size, |
| 320 | + } |
| 321 | + (out_dir / f"msmarco-passages-{count}.meta.json").write_text(json.dumps(meta)) |
| 322 | + |
| 323 | + print(f"[done] wrote {written:,} vectors across {len(shards)} shards") |
| 324 | + |
| 325 | + build_gt_sharded( |
| 326 | + shards=shards, |
| 327 | + total_count=written, |
| 328 | + dim=dim, |
| 329 | + gt_path=out_dir / f"msmarco-passages-{count}.gt.jsonl", |
| 330 | + q_count=Q_COUNT, |
| 331 | + topk=TOPK, |
| 332 | + ) |
| 333 | + |
| 334 | + |
| 335 | +if __name__ == "__main__": |
| 336 | + main() |
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