Datasets:
File size: 3,789 Bytes
f1a4107 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 | from __future__ import annotations
import json
import math
import subprocess
import sys
from pathlib import Path
import pytest
pytest.importorskip("tokenizers")
from tokenizers import Tokenizer, models, pre_tokenizers # noqa: E402
ROOT = Path(__file__).resolve().parents[1]
def build_tokenizer(path: Path) -> None:
vocab = {
"<unk>": 0,
"the": 1,
"quick": 2,
"brown": 3,
"fox": 4,
"jumps": 5,
"over": 6,
"lazy": 7,
"dog": 8,
"second": 9,
"line": 10,
"here": 11,
"third": 12,
"another": 13,
}
tokenizer = Tokenizer(models.WordLevel(vocab=vocab, unk_token="<unk>"))
tokenizer.pre_tokenizer = pre_tokenizers.Whitespace()
tokenizer.save(str(path / "tokenizer.json"))
def write_fixture(tmp_path: Path, *, tokens: int, chunks: int, ppl: float) -> tuple[Path, Path]:
corpus = tmp_path / "corpus.txt"
corpus.write_text(
"the quick brown fox jumps over the lazy dog\n"
"second line here\n"
"third another line here\n" * 4,
encoding="utf-8",
)
tokenizer_dir = tmp_path / "tok"
tokenizer_dir.mkdir()
build_tokenizer(tokenizer_dir)
payload = {
"corpus": str(corpus),
"config": {
"corpus": str(corpus),
"max_sequences": chunks,
"max_tokens": 4,
"min_tokens": 1,
},
"chunks": chunks,
"tokens": tokens,
"bf16_ppl": ppl,
"candidate_ppl": ppl * 1.1,
}
ppl_json = tmp_path / "ppl_en.json"
ppl_json.write_text(json.dumps(payload), encoding="utf-8")
return ppl_json, tokenizer_dir
def run(*args: str) -> subprocess.CompletedProcess[str]:
return subprocess.run(
[sys.executable, str(ROOT / "scripts" / "compute_bpc.py"), *args],
cwd=ROOT,
text=True,
capture_output=True,
check=False,
)
def test_bpc_is_log2_ppl_times_fertility(tmp_path: Path) -> None:
ppl_json, tokenizer_dir = write_fixture(tmp_path, tokens=9, chunks=3, ppl=8.0)
out = tmp_path / "report.json"
result = run("--ppl-json", str(ppl_json), "--tokenizer", str(tokenizer_dir), "--json", str(out))
assert result.returncode == 0, result.stdout + result.stderr
report = json.loads(out.read_text(encoding="utf-8"))[0]
assert report["chunks"] == 3
# every chunk contributes len(chunk) - 1 scored predictions
assert report["tokens"] == report["chunks"] * 3
assert report["chars"] > 0
expected = math.log2(8.0) * report["tokens"] / report["chars"]
assert report["bpc_bf16"] == pytest.approx(expected)
assert report["bpc_candidate"] == pytest.approx(math.log2(8.8) * report["tokens"] / report["chars"])
assert report["reproduced"]["chunks_match"] is True
assert report["reproduced"]["tokens_match"] is True
def test_strict_mode_flags_token_drift(tmp_path: Path) -> None:
ppl_json, tokenizer_dir = write_fixture(tmp_path, tokens=99, chunks=3, ppl=8.0)
result = run("--ppl-json", str(ppl_json), "--tokenizer", str(tokenizer_dir), "--strict")
assert result.returncode == 1
assert "tokens_match" in result.stdout
def test_accepts_corpus_override(tmp_path: Path) -> None:
ppl_json, tokenizer_dir = write_fixture(tmp_path, tokens=9, chunks=3, ppl=8.0)
payload = json.loads(ppl_json.read_text(encoding="utf-8"))
payload["corpus"] = str(tmp_path / "missing.txt")
payload["config"]["corpus"] = str(tmp_path / "missing.txt")
ppl_json.write_text(json.dumps(payload), encoding="utf-8")
override = tmp_path / "corpus.txt"
result = run("--ppl-json", str(ppl_json), "--tokenizer", str(tokenizer_dir), "--corpus", str(override))
assert result.returncode == 0, result.stdout + result.stderr
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