import json
import os
from typing import Dict, Optional, Tuple, Union
import numpy as np
import onnx.helper as oh
import onnx.numpy_helper as onh
from onnx import ModelProto, load, TensorProto
def _make_stat(init: TensorProto) -> Dict[str, float]:
"""
Produces statistics.
:param init: tensor
:return statistics
"""
ar = onh.to_array(init)
return dict(
mean=float(ar.mean()),
std=float(ar.std()),
shape=ar.shape,
itype=oh.np_dtype_to_tensor_dtype(ar.dtype),
min=float(ar.min()),
max=float(ar.max()),
)
[docs]
def onnx_lighten(
onx: Union[str, ModelProto],
verbose: int = 0,
) -> Tuple[ModelProto, Dict[str, Dict[str, float]]]:
"""
Creates a model without big initializers but stores statistics
into dictionaries. The function can be reversed with
:func:`experimental_experiment.onnx_tools.onnx_unlighten`.
The model is modified inplace.
:param onx: model
:param verbose: verbosity
:return: new model, statistics
"""
if isinstance(onx, str):
if verbose:
print(f"[onnx_lighten] load {onx!r}")
model = load(onx)
else:
assert isinstance(onx, ModelProto), f"Unexpected type {type(onx)}"
model = onx
keep = []
stats = []
for init in model.graph.initializer:
shape = init.dims
size = np.prod(shape)
if size > 2**12:
stat = _make_stat(init)
stats.append((init.name, stat))
if verbose:
print(f"[onnx_lighten] remove initializer {init.name!r} stat={stat}")
else:
keep.append(init)
del model.graph.initializer[:]
model.graph.initializer.extend(keep)
return model, dict(stats)
def _get_tensor(min=None, max=None, mean=None, std=None, shape=None, itype=None):
assert itype is not None, "itype must be specified."
assert shape is not None, "shape must be specified."
dtype = oh.tensor_dtype_to_np_dtype(itype)
if (mean is None or std is None) or (
min is not None and max is not None and abs(max - min - 1) < 0.01
):
if min is None:
min = 0
if max is None:
max = 0
return (np.random.random(shape) * (max - min) + min).astype(dtype)
assert std is not None and mean is not None, f"mean={mean} or std={std} is None"
t = np.random.randn(*shape).astype(dtype)
return t
[docs]
def onnx_unlighten(
onx: Union[str, ModelProto],
stats: Optional[Dict[str, Dict[str, float]]] = None,
verbose: int = 0,
) -> ModelProto:
"""
Function fixing the model produced by function
:func:`experimental_experiment.onnx_tools.onnx_lighten`.
The model is modified inplace.
:param onx: model
:param stats: statics, can be None if onx is a file,
then it loads the file ``<filename>.stats``,
it assumes it is json format
:param verbose: verbosity
:return: new model, statistics
"""
if isinstance(onx, str):
if stats is None:
fstats = f"{onx}.stats"
assert os.path.exists(fstats), f"File {fstats!r} is missing."
if verbose:
print(f"[onnx_unlighten] load {fstats!r}")
with open(fstats, "r") as f:
stats = json.load(f)
if verbose:
print(f"[onnx_unlighten] load {onx!r}")
model = load(onx)
else:
assert isinstance(onx, ModelProto), f"Unexpected type {type(onx)}"
model = onx
assert stats is not None, "stats is missing"
keep = []
for name, stat in stats.items():
t = _get_tensor(**stat)
init = onh.from_array(t, name=name)
keep.append(init)
model.graph.initializer.extend(keep)
return model