AstrAI/scripts/eval/evaluate_ifd.py

513 lines
17 KiB
Python

"""IFD (Instruction Following Difficulty) data quality scoring.
IFD = conditional_NLL / unconditional_NLL
- Messages format: plain text concatenation (no chat template)
- Plain format: raw instr_key + resp_key fields
v2 changelog:
- Same token set: unconditional pass prefixes resp with a plain-text sentinel
(default ``\\n``; use ``--sentinel_text ""`` for bos/pad fallback).
Both branches predict the identical N resp tokens.
Single-token answers (rl=1) are now supported.
- ctx_len tracked in output
- skip_reason for None samples (no more silent None)
- --per_token for per-token IFD breakdown
"""
import argparse
import glob
import json
import os
import statistics
import torch
import torch.nn.functional as F
import tqdm
from astrai.model import AutoModel
from astrai.tokenize import AutoTokenizer
def _pack_bins(pairs, max_len):
"""BFD bin packing: pack (c+r) into bins of max total length."""
indexed = sorted(enumerate(pairs), key=lambda x: -(len(x[1][0]) + len(x[1][1])))
bins = []
lengths = []
for orig_idx, (c, r) in indexed:
size = len(c) + len(r)
best_bin = -1
for bi, rem in enumerate(lengths):
if rem >= size:
if best_bin < 0 or rem < lengths[best_bin]:
best_bin = bi
if best_bin >= 0:
bins[best_bin].append((orig_idx, c, r))
lengths[best_bin] -= size
else:
bins.append([(orig_idx, c, r)])
lengths.append(max_len - size)
return bins
def _resolve_sentinel_ids(tokenizer, sentinel_text):
"""Tokenize the sentinel text for the unconditional pass prefix.
Falls back to bos/pad_token_id when sentinel_text is empty or
cannot be encoded.
"""
if sentinel_text:
ids = tokenizer.encode(sentinel_text, add_special_tokens=False)
if ids:
return ids
for attr in ("bos_token_id", "pad_token_id", "eos_token_id"):
tid = getattr(tokenizer, attr, None)
if tid is not None:
return [tid]
return [0]
def _collect_input_files(input_path: str) -> list:
"""Resolve *input_path* to a list of JSONL/JSON files."""
if os.path.isdir(input_path):
files = []
for ext in ("*.jsonl", "*.json"):
files.extend(
sorted(glob.glob(os.path.join(input_path, "**", ext), recursive=True))
)
return files
return sorted(glob.glob(input_path))
def _load_items(filepath: str) -> list:
"""Load JSONL or JSON (array / single dict) into a list of dicts."""
with open(filepath, "r", encoding="utf-8") as f:
if filepath.lower().endswith(".json"):
data = json.load(f)
if isinstance(data, dict):
return [data]
return data
return [json.loads(line) for line in f if line.strip()]
@torch.inference_mode()
def _score_batch(
pairs, model, device, max_len=2048, sentinel_ids=None, per_token=False
):
"""BFD-packed IFD with text-sentinel-anchored unconditional pass.
Conditional: (ctx + resp[0..i-1]) → resp[i], i = 0..N-1
Unconditional: (<sentinel> + resp[0..i-1]) → resp[i], i = 0..N-1
Both branches predict the identical N response tokens. A short
plain-text sentinel gives the unconditional pass a prefix so that
every response token can be predicted. Single-token answers (rl=1)
are supported.
"""
if not pairs:
return []
if sentinel_ids is None:
sentinel_ids = [0]
bins = _pack_bins(pairs, max_len)
result = [None] * len(pairs)
# ---- conditional pass (packed, per-document position IDs) ----
for bin_items in bins:
seq_ids = []
global_pos = []
doc_ids = []
doc_offsets = []
for di, (orig_idx, c, r) in enumerate(bin_items):
ctx_len = len(c)
start = len(seq_ids)
item_len = len(c) + len(r)
seq_ids.extend(c)
seq_ids.extend(r)
end = len(seq_ids)
global_pos.extend(range(item_len))
doc_ids.extend([di] * item_len)
doc_offsets.append((start, end, orig_idx, ctx_len))
full_ids = torch.tensor([seq_ids], device=device, dtype=torch.long)
pos_ids = torch.tensor([global_pos], device=device, dtype=torch.long)
seq_len = len(seq_ids)
causal = torch.tril(
torch.ones(seq_len, seq_len, dtype=torch.bool, device=device)
)
doc_t = torch.tensor([doc_ids], device=device)
doc_mask = doc_t.unsqueeze(-1) == doc_t.unsqueeze(-2)
attn_mask = (causal & doc_mask[0]).unsqueeze(0).unsqueeze(0)
logits_full = model(full_ids, position_ids=pos_ids, input_mask=attn_mask)[
"logits"
][0]
for start, end, orig_idx, ctx_len in doc_offsets:
rl = end - start - ctx_len
resp_start = start + ctx_len - 1
resp_logits = logits_full[resp_start : end - 1]
resp_targets = torch.tensor(
seq_ids[start + ctx_len : end], device=device, dtype=torch.long
)
cond_losses = F.cross_entropy(
resp_logits, resp_targets, reduction="none"
).cpu()
result[orig_idx] = {
"_cond_losses": cond_losses,
"_rl": rl,
"_ctx_len": ctx_len,
}
# ---- unconditional pass (sentinel-prefixed, batched 2D) ----
valid_items = [
(
i,
result[i]["_rl"],
result[i]["_ctx_len"],
result[i]["_cond_losses"],
pairs[i][1],
)
for i in range(len(pairs))
if result[i] is not None and "_cond_losses" in result[i]
]
if not valid_items:
return result
valid_items.sort(key=lambda x: -x[1])
prefix_len = len(sentinel_ids)
max_rl = prefix_len + max(rl for _, rl, _, _, _ in valid_items)
bsz = len(valid_items)
u_batch = torch.zeros(bsz, max_rl, dtype=torch.long, device=device)
for ri, (_, rl, _, _, r_ids) in enumerate(valid_items):
u_batch[ri, :prefix_len] = torch.tensor(sentinel_ids, dtype=torch.long)
u_batch[ri, prefix_len : prefix_len + rl] = torch.tensor(
r_ids, dtype=torch.long
)
logits_resp = model(u_batch)["logits"]
for ri, (orig_idx, rl, ctx_len, cond_losses, _) in enumerate(valid_items):
unp_logits = logits_resp[ri, prefix_len - 1 : prefix_len - 1 + rl]
unp_targets = u_batch[ri, prefix_len : prefix_len + rl]
uncond_losses = F.cross_entropy(unp_logits, unp_targets, reduction="none").cpu()
L_cond = cond_losses.mean().item()
L_uncond = uncond_losses.mean().item()
ifd = L_cond / L_uncond if L_uncond > 0 else None
out = {
"L_cond": round(L_cond, 6),
"L_uncond": round(L_uncond, 6),
"ifd": round(ifd, 6) if ifd is not None else None,
"ctx_len": ctx_len,
"resp_len": rl,
}
if per_token:
per = [
(round(c.item() / u.item(), 6) if u.item() > 0 else None)
for c, u in zip(cond_losses, uncond_losses)
]
out["ifd_per_token"] = per
result[orig_idx] = out
return result
def _trim(context_ids, resp_ids, max_len):
"""Truncate to fit max_len, keeping response intact if possible."""
if len(resp_ids) > max_len // 2:
resp_ids = resp_ids[: max_len // 2]
full_ids = context_ids + resp_ids
if len(full_ids) <= max_len:
return context_ids, resp_ids
overflow = len(full_ids) - max_len
if overflow >= len(context_ids):
return [], resp_ids[:max_len]
return context_ids[overflow:], resp_ids
def process_file(
model,
tokenizer,
input_file,
output_file,
instr_key,
resp_key,
max_len=2048,
data_format="plain",
batch_size=1,
device=None,
sentinel_ids=None,
per_token=False,
max_samples=None,
):
"""Score a single file, write per-sample JSONL, return summary stats."""
if device is None:
device = "cuda" if torch.cuda.is_available() else "cpu"
if sentinel_ids is None:
sentinel_ids = _resolve_sentinel_ids(tokenizer, "\n")
data = _load_items(input_file)
if max_samples and len(data) > max_samples:
import random
data = random.sample(data, max_samples)
results = []
all_ifds = []
buffer = []
label = os.path.splitext(os.path.basename(input_file))[0]
for item in tqdm.tqdm(data, desc=f" {label}", unit="sample", leave=False):
if data_format == "messages":
turns = []
for i, msg in enumerate(item.get("messages", [])):
if msg.get("role") != "assistant":
continue
ctx_text = "\n\n".join(m["content"] for m in item["messages"][:i])
ctx_ids = tokenizer.encode(ctx_text)
resp_ids = tokenizer.encode(msg["content"], add_special_tokens=False)
ctx_ids, resp_ids = _trim(ctx_ids, resp_ids, max_len)
if ctx_ids and resp_ids:
turns.append((ctx_ids, resp_ids))
if not turns:
results.append(
{
**item,
"ifd": None,
"skip_reason": "no valid assistant turns",
"ifd_turns": [],
}
)
continue
buffer.append((item, turns, "messages"))
else:
ctx_ids = tokenizer.encode(item[instr_key], add_special_tokens=False)
resp_ids = tokenizer.encode(item[resp_key], add_special_tokens=False)
ctx_ids, resp_ids = _trim(ctx_ids, resp_ids, max_len)
if not ctx_ids or not resp_ids:
results.append(
{
**item,
"ifd": None,
"ifd_detail": {"skip_reason": "empty ctx or resp"},
}
)
continue
buffer.append((item, [(ctx_ids, resp_ids)], "plain"))
if len(buffer) >= batch_size:
_flush_buffer(
buffer,
results,
all_ifds,
model,
device,
max_len,
sentinel_ids,
per_token,
)
if buffer:
_flush_buffer(
buffer, results, all_ifds, model, device, max_len, sentinel_ids, per_token
)
with open(output_file, "w", encoding="utf-8") as f:
for item in results:
f.write(json.dumps(item, ensure_ascii=False) + "\n")
valid_ifd = [v for v in all_ifds if v is not None]
stats = {
"samples": len(data),
"valid_ifd": len(valid_ifd),
"skipped": len(data) - len(valid_ifd),
}
if valid_ifd:
stats["mean_ifd"] = statistics.mean(valid_ifd)
stats["median_ifd"] = statistics.median(valid_ifd)
if len(valid_ifd) > 1:
stats["stdev_ifd"] = statistics.stdev(valid_ifd)
stats["min_ifd"] = min(valid_ifd)
stats["max_ifd"] = max(valid_ifd)
print(f"\n{'=' * 50}")
print(f" [{label}]")
print(f"{'=' * 50}")
print(f" Samples: {len(data)}")
print(f" Valid IFD: {len(valid_ifd)}")
print(f" Skipped: {len(data) - len(valid_ifd)}")
print(f" Mean IFD: {statistics.mean(valid_ifd):.4f}")
print(f" Median IFD: {statistics.median(valid_ifd):.4f}")
if len(valid_ifd) > 1:
print(f" Stdev IFD: {statistics.stdev(valid_ifd):.4f}")
print(f" Min IFD: {min(valid_ifd):.4f}")
print(f" Max IFD: {max(valid_ifd):.4f}")
print(f"{'=' * 50}")
print(f" Results saved to {output_file}")
return stats
def _flush_buffer(
buffer, results, all_ifds, model, device, max_len, sentinel_ids, per_token
):
all_pairs = []
indices = []
for item, turns, fmt in buffer:
start = len(all_pairs)
all_pairs.extend(turns)
indices.append((item, turns, fmt, start, len(all_pairs)))
raw = _score_batch(
all_pairs,
model,
device,
max_len,
sentinel_ids=sentinel_ids,
per_token=per_token,
)
for item, turns, fmt, start, end in indices:
turn_scores = raw[start:end]
if fmt == "messages":
valid = [
s for s in turn_scores if s is not None and s.get("ifd") is not None
]
if not valid:
results.append({**item, "ifd": None, "ifd_turns": turn_scores})
else:
avg = sum(s["ifd"] for s in valid) / len(valid)
all_ifds.append(avg)
results.append(
{
**item,
"ifd": avg,
"ifd_detail": valid[0] if len(valid) == 1 else None,
"ifd_turns": turn_scores,
}
)
else:
score = turn_scores[0]
all_ifds.append(score.get("ifd"))
results.append({**item, "ifd": score.get("ifd"), "ifd_detail": score})
buffer.clear()
def main():
parser = argparse.ArgumentParser(
description="Compute IFD scores for instruction-response data"
)
parser.add_argument("--param_path", type=str, required=True, help="Model directory")
parser.add_argument(
"--input_path",
type=str,
required=True,
help="Input file, glob pattern, or directory.",
)
parser.add_argument(
"--output_dir",
type=str,
required=True,
help="Directory for output files (summary.json + per-file JSONL).",
)
parser.add_argument("--max_len", type=int, default=2048, help="Max token length")
parser.add_argument(
"--format",
type=str,
default="plain",
choices=["plain", "messages"],
help="Input format",
)
parser.add_argument(
"--instr_key", type=str, default="instruction", help="Key for instruction field"
)
parser.add_argument(
"--resp_key", type=str, default="response", help="Key for response field"
)
parser.add_argument(
"--batch_size", type=int, default=8, help="Batch size for model forward passes"
)
parser.add_argument("--device", type=str, default=None, help="Device (e.g. cuda:0)")
parser.add_argument(
"--dtype",
type=str,
default="bfloat16" if torch.cuda.is_available() else "float32",
help="Torch dtype",
)
parser.add_argument(
"--sentinel_text",
type=str,
default="\n",
help='Plain-text prefix for unconditional pass (default: "\\n"). Use "" for bos/pad fallback.',
)
parser.add_argument(
"--per_token",
action="store_true",
help="Include per-token IFD breakdown in output",
)
parser.add_argument(
"--max_samples",
type=int,
default=None,
help="Maximum number of samples per file (random subsample). Default: all.",
)
args = parser.parse_args()
if args.device is None:
args.device = "cuda" if torch.cuda.is_available() else "cpu"
dtype = getattr(torch, args.dtype)
print(f"Loading model from {args.param_path} ...")
model = AutoModel.from_pretrained(args.param_path)
tokenizer = AutoTokenizer.from_pretrained(args.param_path)
model.to(device=args.device, dtype=dtype)
model.eval()
sentinel_ids = _resolve_sentinel_ids(tokenizer, args.sentinel_text)
input_files = _collect_input_files(args.input_path)
if not input_files:
print(f"No input files found at {args.input_path}")
return
print(f"Found {len(input_files)} file(s) to evaluate")
os.makedirs(args.output_dir, exist_ok=True)
all_stats = {}
for filepath in input_files:
label = os.path.splitext(os.path.basename(filepath))[0]
output_file = os.path.join(args.output_dir, f"{label}_ifd.jsonl")
stats = process_file(
model=model,
tokenizer=tokenizer,
input_file=filepath,
output_file=output_file,
instr_key=args.instr_key,
resp_key=args.resp_key,
max_len=args.max_len,
data_format=args.format,
batch_size=args.batch_size,
device=args.device,
sentinel_ids=sentinel_ids,
per_token=args.per_token,
max_samples=args.max_samples,
)
all_stats[label] = stats
summary_path = os.path.join(args.output_dir, "summary.json")
with open(summary_path, "w", encoding="utf-8") as f:
json.dump(all_stats, f, ensure_ascii=False, indent=2)
print(f"\nSummary saved to {summary_path}")
if __name__ == "__main__":
main()