Source code for revive.data.batch

''''''
"""
MIT License

Copyright (c) 2020 Tianshou contributors

Permission is hereby granted, free of charge, to any person obtaining a copy
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SOFTWARE.
"""
import pprint
import warnings 
from collections.abc import Collection
from copy import deepcopy
from numbers import Number
from typing import Any, Dict, Iterable, Iterator, List, Optional, Sequence, Union

import numpy as np
import torch

IndexType = Union[slice, int, np.ndarray, List[int]]


def _is_batch_set(data: Any) -> bool:
    # Batch set is a list/tuple of dict/Batch objects,
    # or 1-D np.ndarray with object type,
    # where each element is a dict/Batch object
    if isinstance(data, np.ndarray):  # most often case
        # "for e in data" will just unpack the first dimension,
        # but data.tolist() will flatten ndarray of objects
        # so do not use data.tolist()
        return data.dtype == object and all(isinstance(e, (dict, Batch)) for e in data)
    elif isinstance(data, (list, tuple)):
        if len(data) > 0 and all(isinstance(e, (dict, Batch)) for e in data):
            return True
    return False


def _is_scalar(value: Any) -> bool:
    # check if the value is a scalar
    # 1. python bool object, number object: isinstance(value, Number)
    # 2. numpy scalar: isinstance(value, np.generic)
    # 3. python object rather than dict / Batch / tensor
    # the check of dict / Batch is omitted because this only checks a value.
    # a dict / Batch will eventually check their values
    if isinstance(value, torch.Tensor):
        return value.numel() == 1 and not value.shape
    else:
        # np.asanyarray will cause dead loop in some cases
        return np.isscalar(value)


def _is_number(value: Any) -> bool:
    # isinstance(value, Number) checks 1, 1.0, np.int(1), np.float(1.0), etc.
    # isinstance(value, np.nummber) checks np.int32(1), np.float64(1.0), etc.
    # isinstance(value, np.bool_) checks np.bool_(True), etc.
    # similar to np.isscalar but np.isscalar('st') returns True
    return isinstance(value, (Number, np.number, np.bool_))


def _to_array_with_correct_type(v: Any) -> np.ndarray:
    if isinstance(v, np.ndarray) and issubclass(v.dtype.type, (np.bool_, np.number)):
        return v  # most often case
    # convert the value to np.ndarray
    # convert to object data type if neither bool nor number
    # raises an exception if array's elements are tensors themselves
    v = np.asanyarray(v)
    if not issubclass(v.dtype.type, (np.bool_, np.number)):
        v = v.astype(object)
    if v.dtype == object:
        # scalar ndarray with object data type is very annoying
        # a=np.array([np.array({}, dtype=object), np.array({}, dtype=object)])
        # a is not array([{}, {}], dtype=object), and a[0]={} results in
        # something very strange:
        # array([{}, array({}, dtype=object)], dtype=object)
        if not v.shape:
            v = v.item(0)
        elif all(isinstance(e, np.ndarray) for e in v.reshape(-1)):
            return v  # various length, np.array([[1], [2, 3], [4, 5, 6]])
        elif any(isinstance(e, torch.Tensor) for e in v.reshape(-1)):
            raise ValueError("Numpy arrays of tensors are not supported yet.")
    return v


def _create_value(
    inst: Any,
    size: int,
    stack: bool = True,
) -> Union["Batch", np.ndarray, torch.Tensor]:
    """Create empty place-holders accroding to inst's shape.
    :param bool stack: whether to stack or to concatenate. E.g. if inst has shape of
        (3, 5), size = 10, stack=True returns an np.ndarry with shape of (10, 3, 5),
        otherwise (10, 5)
    """
    has_shape = isinstance(inst, (np.ndarray, torch.Tensor))
    is_scalar = _is_scalar(inst)
    if not stack and is_scalar:
        # should never hit since it has already checked in Batch.cat_ , here we do not
        # consider scalar types, following the behavior of numpy which does not support
        # concatenation of zero-dimensional arrays (scalars)
        raise TypeError(f"cannot concatenate with {inst} which is scalar")
    if has_shape:
        shape = (size, *inst.shape) if stack else (size, *inst.shape[1:])
    if isinstance(inst, np.ndarray):
        target_type = inst.dtype.type if issubclass(
            inst.dtype.type, (np.bool_, np.number)
        ) else object
        return np.full(
            shape, fill_value=None if target_type == object else 0, dtype=target_type
        )
    elif isinstance(inst, torch.Tensor):
        return torch.full(shape, fill_value=0, device=inst.device, dtype=inst.dtype)
    elif isinstance(inst, (dict, Batch)):
        zero_batch = Batch()
        for key, val in inst.items():
            zero_batch.__dict__[key] = _create_value(val, size, stack=stack)
        return zero_batch
    elif is_scalar:
        return _create_value(np.asarray(inst), size, stack=stack)
    else:  # fall back to object
        return np.array([None for _ in range(size)], object)


def _assert_type_keys(keys: Iterable[str]) -> None:
    assert all(isinstance(e, str) for e in keys), \
        f"keys should all be string, but got {keys}"


def _parse_value(v: Any) -> Optional[Union["Batch", np.ndarray, torch.Tensor]]:
    if isinstance(v, Batch):  # most often case
        return v
    elif (isinstance(v, np.ndarray) and
          issubclass(v.dtype.type, (np.bool_, np.number))) or \
            isinstance(v, torch.Tensor) or v is None:  # third often case
        return v
    elif _is_number(v):  # second often case, but it is more time-consuming
        return np.asanyarray(v)
    elif isinstance(v, dict):
        return Batch(v)
    else:
        if not isinstance(v, np.ndarray) and isinstance(v, Collection) and \
                len(v) > 0 and all(isinstance(e, torch.Tensor) for e in v):
            try:
                return torch.stack(v)  # type: ignore
            except RuntimeError as e:
                raise TypeError(
                    "Batch does not support non-stackable iterable"
                    " of torch.Tensor as unique value yet."
                ) from e
        if _is_batch_set(v):
            v = Batch(v)  # list of dict / Batch
        else:
            # None, scalar, normal data list (main case)
            # or an actual list of objects
            try:
                v = _to_array_with_correct_type(v)
            except ValueError as e:
                raise TypeError(
                    "Batch does not support heterogeneous list/"
                    "tuple of tensors as unique value yet."
                ) from e
        return v


def _alloc_by_keys_diff(
    meta: "Batch", batch: "Batch", size: int, stack: bool = True
) -> None:
    for key in batch.keys():
        if key in meta.keys():
            if isinstance(meta[key], Batch) and isinstance(batch[key], Batch):
                _alloc_by_keys_diff(meta[key], batch[key], size, stack)
            elif isinstance(meta[key], Batch) and meta[key].is_empty():
                meta[key] = _create_value(batch[key], size, stack)
        else:
            meta[key] = _create_value(batch[key], size, stack)


[docs]class Batch: def __init__( self, batch_dict: Optional[Union[dict, "Batch", Sequence[Union[dict, "Batch"]], np.ndarray]] = None, copy: bool = False, **kwargs: Any, ) -> None: if copy: batch_dict = deepcopy(batch_dict) if batch_dict is not None: if isinstance(batch_dict, (dict, Batch)): _assert_type_keys(batch_dict.keys()) for k, v in batch_dict.items(): self.__dict__[k] = _parse_value(v) elif _is_batch_set(batch_dict): self.stack_(batch_dict) # type: ignore if len(kwargs) > 0: self.__init__(kwargs, copy=copy) # type: ignore def __setattr__(self, key: str, value: Any) -> None: """Set self.key = value.""" self.__dict__[key] = _parse_value(value) def __getattr__(self, key: str) -> Any: """Return self.key. The "Any" return type is needed for mypy.""" return getattr(self.__dict__, key) def __contains__(self, key: str) -> bool: """Return key in self.""" return key in self.__dict__ def __getstate__(self) -> Dict[str, Any]: """Pickling interface. Only the actual data are serialized for both efficiency and simplicity. """ state = {} for k, v in self.items(): if isinstance(v, Batch): v = v.__getstate__() state[k] = v return state def __setstate__(self, state: Dict[str, Any]) -> None: """Unpickling interface. At this point, self is an empty Batch instance that has not been initialized, so it can safely be initialized by the pickle state. """ self.__init__(**state) # type: ignore
[docs] def __getitem__(self, index: Union[str, IndexType]) -> Any: """Return self[index].""" if isinstance(index, str): return self.__dict__[index] batch_items = self.items() if len(batch_items) > 0: b = Batch() for k, v in batch_items: if isinstance(v, Batch) and v.is_empty(): b.__dict__[k] = Batch() else: b.__dict__[k] = v[index] return b else: raise IndexError("Cannot access item from empty Batch object.")
[docs] def __setitem__(self, index: Union[str, IndexType], value: Any) -> None: """Assign value to self[index].""" value = _parse_value(value) if isinstance(index, str): self.__dict__[index] = value return if not isinstance(value, Batch): raise ValueError( "Batch does not supported tensor assignment. " "Use a compatible Batch or dict instead." ) if not set(value.keys()).issubset(self.__dict__.keys()): raise ValueError("Creating keys is not supported by item assignment.") for key, val in self.items(): try: self.__dict__[key][index] = value[key] except KeyError: if isinstance(val, Batch): self.__dict__[key][index] = Batch() elif isinstance(val, torch.Tensor) or \ (isinstance(val, np.ndarray) and issubclass(val.dtype.type, (np.bool_, np.number))): self.__dict__[key][index] = 0 else: self.__dict__[key][index] = None
def __iadd__(self, other: Union["Batch", Number, np.number]) -> "Batch": """Algebraic addition with another Batch instance in-place.""" if isinstance(other, Batch): for (k, r), v in zip( self.__dict__.items(), other.__dict__.values() ): # TODO are keys consistent? if isinstance(r, Batch) and r.is_empty(): continue else: self.__dict__[k] += v return self elif _is_number(other): for k, r in self.items(): if isinstance(r, Batch) and r.is_empty(): continue else: self.__dict__[k] += other return self else: raise TypeError("Only addition of Batch or number is supported.") def __add__(self, other: Union["Batch", Number, np.number]) -> "Batch": """Algebraic addition with another Batch instance out-of-place.""" return deepcopy(self).__iadd__(other) def __imul__(self, val: Union[Number, np.number]) -> "Batch": """Algebraic multiplication with a scalar value in-place.""" assert _is_number(val), "Only multiplication by a number is supported." for k, r in self.__dict__.items(): if isinstance(r, Batch) and r.is_empty(): continue self.__dict__[k] *= val return self def __mul__(self, val: Union[Number, np.number]) -> "Batch": """Algebraic multiplication with a scalar value out-of-place.""" return deepcopy(self).__imul__(val) def __itruediv__(self, val: Union[Number, np.number]) -> "Batch": """Algebraic division with a scalar value in-place.""" assert _is_number(val), "Only division by a number is supported." for k, r in self.__dict__.items(): if isinstance(r, Batch) and r.is_empty(): continue self.__dict__[k] /= val return self def __truediv__(self, val: Union[Number, np.number]) -> "Batch": """Algebraic division with a scalar value out-of-place.""" return deepcopy(self).__itruediv__(val) def __repr__(self) -> str: """Return str(self).""" s = self.__class__.__name__ + "(\n" flag = False for k, v in self.__dict__.items(): rpl = "\n" + " " * (6 + len(k)) obj = pprint.pformat(v).replace("\n", rpl) s += f" {k}: {obj},\n" flag = True if flag: s += ")" else: s = self.__class__.__name__ + "()" return s
[docs] def to_numpy(self) -> None: """Change all torch.Tensor to numpy.ndarray in-place.""" for k, v in self.items(): if isinstance(v, torch.Tensor): self.__dict__[k] = v.detach().cpu().numpy() elif isinstance(v, Batch): v.to_numpy()
[docs] def to_torch( self, dtype: Optional[torch.dtype] = None, device: Union[str, int, torch.device] = "cpu", ) -> None: """Change all numpy.ndarray to torch.Tensor in-place.""" if not isinstance(device, torch.device): device = torch.device(device) for k, v in self.items(): if isinstance(v, torch.Tensor): if dtype is not None and v.dtype != dtype or \ v.device.type != device.type or \ device.index != v.device.index: if dtype is not None: v = v.type(dtype) self.__dict__[k] = v.to(device) elif isinstance(v, Batch): v.to_torch(dtype, device) else: # ndarray or scalar if not isinstance(v, np.ndarray): v = np.asanyarray(v) v = torch.from_numpy(v).to(device) if dtype is not None: v = v.type(dtype) self.__dict__[k] = v
def __cat(self, batches: Sequence[Union[dict, "Batch"]], lens: List[int]) -> None: # partial keys will be padded by zeros # with the shape of [len, rest_shape] sum_lens = [0] for x in lens: sum_lens.append(sum_lens[-1] + x) # collect non-empty keys keys_map = [ set( k for k, v in batch.items() if not (isinstance(v, Batch) and v.is_empty()) ) for batch in batches ] keys_shared = set.intersection(*keys_map) values_shared = [[e[k] for e in batches] for k in keys_shared] for k, v in zip(keys_shared, values_shared): if all(isinstance(e, (dict, Batch)) for e in v): batch_holder = Batch() batch_holder.__cat(v, lens=lens) self.__dict__[k] = batch_holder elif all(isinstance(e, torch.Tensor) for e in v): self.__dict__[k] = torch.cat(v) else: # cat Batch(a=np.zeros((3, 4))) and Batch(a=Batch(b=Batch())) # will fail here v = np.concatenate(v) self.__dict__[k] = _to_array_with_correct_type(v) keys_total = set.union(*[set(b.keys()) for b in batches]) keys_reserve_or_partial = set.difference(keys_total, keys_shared) # keys that are reserved in all batches keys_reserve = set.difference(keys_total, set.union(*keys_map)) # keys that occur only in some batches, but not all keys_partial = keys_reserve_or_partial.difference(keys_reserve) for k in keys_reserve: # reserved keys self.__dict__[k] = Batch() for k in keys_partial: for i, e in enumerate(batches): if k not in e.__dict__: continue val = e.get(k) if isinstance(val, Batch) and val.is_empty(): continue try: self.__dict__[k][sum_lens[i]:sum_lens[i + 1]] = val except KeyError: self.__dict__[k] = _create_value(val, sum_lens[-1], stack=False) self.__dict__[k][sum_lens[i]:sum_lens[i + 1]] = val
[docs] def cat_(self, batches: Union["Batch", Sequence[Union[dict, "Batch"]]]) -> None: """Concatenate a list of (or one) Batch objects into current batch.""" if isinstance(batches, Batch): batches = [batches] # check input format batch_list = [] for b in batches: if isinstance(b, dict): if len(b) > 0: batch_list.append(Batch(b)) elif isinstance(b, Batch): # x.is_empty() means that x is Batch() and should be ignored if not b.is_empty(): batch_list.append(b) else: raise ValueError(f"Cannot concatenate {type(b)} in Batch.cat_") if len(batch_list) == 0: return batches = batch_list try: # x.is_empty(recurse=True) here means x is a nested empty batch # like Batch(a=Batch), and we have to treat it as length zero and # keep it. lens = [0 if x.is_empty(recurse=True) else len(x) for x in batches] except TypeError as e: raise ValueError( "Batch.cat_ meets an exception. Maybe because there is any " f"scalar in {batches} but Batch.cat_ does not support the " "concatenation of scalar." ) from e if not self.is_empty(): batches = [self] + list(batches) lens = [0 if self.is_empty(recurse=True) else len(self)] + lens self.__cat(batches, lens)
[docs] @staticmethod def cat(batches: Sequence[Union[dict, "Batch"]]) -> "Batch": batch = Batch() batch.cat_(batches) return batch
[docs] def stack_(self, batches: Sequence[Union[dict, "Batch"]], axis: int = 0) -> None: """Stack a list of Batch object into current batch.""" # check input format batch_list = [] for b in batches: if isinstance(b, dict): if len(b) > 0: batch_list.append(Batch(b)) elif isinstance(b, Batch): # x.is_empty() means that x is Batch() and should be ignored if not b.is_empty(): batch_list.append(b) else: raise ValueError(f"Cannot concatenate {type(b)} in Batch.stack_") if len(batch_list) == 0: return batches = batch_list if not self.is_empty(): batches = [self] + batches # collect non-empty keys keys_map = [ set( k for k, v in batch.items() if not (isinstance(v, Batch) and v.is_empty()) ) for batch in batches ] keys_shared = set.intersection(*keys_map) values_shared = [[e[k] for e in batches] for k in keys_shared] for k, v in zip(keys_shared, values_shared): if all(isinstance(e, torch.Tensor) for e in v): # second often self.__dict__[k] = torch.stack(v, axis) elif all(isinstance(e, (Batch, dict)) for e in v): # third often self.__dict__[k] = Batch.stack(v, axis) else: # most often case is np.ndarray try: self.__dict__[k] = _to_array_with_correct_type(np.stack(v, axis)) except ValueError: warnings.warn( "You are using tensors with different shape," " fallback to dtype=object by default." ) self.__dict__[k] = np.array(v, dtype=object) # all the keys keys_total = set.union(*[set(b.keys()) for b in batches]) # keys that are reserved in all batches keys_reserve = set.difference(keys_total, set.union(*keys_map)) # keys that are either partial or reserved keys_reserve_or_partial = set.difference(keys_total, keys_shared) # keys that occur only in some batches, but not all keys_partial = keys_reserve_or_partial.difference(keys_reserve) if keys_partial and axis != 0: raise ValueError( f"Stack of Batch with non-shared keys {keys_partial} is only " f"supported with axis=0, but got axis={axis}!" ) for k in keys_reserve: # reserved keys self.__dict__[k] = Batch() for k in keys_partial: for i, e in enumerate(batches): if k not in e.__dict__: continue val = e.get(k) if isinstance(val, Batch) and val.is_empty(): continue try: self.__dict__[k][i] = val except KeyError: self.__dict__[k] = _create_value(val, len(batches)) self.__dict__[k][i] = val
[docs] @staticmethod def stack(batches: Sequence[Union[dict, "Batch"]], axis: int = 0) -> "Batch": batch = Batch() batch.stack_(batches, axis) return batch
[docs] def empty_(self, index: Optional[Union[slice, IndexType]] = None) -> "Batch": for k, v in self.items(): if isinstance(v, torch.Tensor): # most often case self.__dict__[k][index] = 0 elif v is None: continue elif isinstance(v, np.ndarray): if v.dtype == object: self.__dict__[k][index] = None else: self.__dict__[k][index] = 0 elif isinstance(v, Batch): self.__dict__[k].empty_(index=index) else: # scalar value warnings.warn( "You are calling Batch.empty on a NumPy scalar, " "which may cause undefined behaviors." ) if _is_number(v): self.__dict__[k] = v.__class__(0) else: self.__dict__[k] = None return self
[docs] @staticmethod def empty(batch: "Batch", index: Optional[IndexType] = None) -> "Batch": return deepcopy(batch).empty_(index)
[docs] def update( self, batch: Optional[Union[dict, "Batch"]] = None, **kwargs: Any ) -> None: """Update this batch from another dict/Batch.""" if batch is None: self.update(kwargs) return for k, v in batch.items(): self.__dict__[k] = _parse_value(v) if kwargs: self.update(kwargs)
[docs] def __len__(self) -> int: """Return len(self).""" r = [] for v in self.__dict__.values(): if isinstance(v, Batch) and v.is_empty(recurse=True): continue elif hasattr(v, "__len__") and (isinstance(v, Batch) or v.ndim > 0): r.append(len(v)) else: raise TypeError(f"Object {v} in {self} has no len()") if len(r) == 0: # empty batch has the shape of any, like the tensorflow '?' shape. # So it has no length. raise TypeError(f"Object {self} has no len()") return min(r)
[docs] def is_empty(self, recurse: bool = False) -> bool: if len(self.__dict__) == 0: return True if not recurse: return False return all( False if not isinstance(x, Batch) else x.is_empty(recurse=True) for x in self.values() )
@property def shape(self) -> List[int]: """Return self.shape.""" if self.is_empty(): return [] else: data_shape = [] for v in self.__dict__.values(): try: data_shape.append(list(v.shape)) except AttributeError: data_shape.append([]) return list(map(min, zip(*data_shape))) if len(data_shape) > 1 \ else data_shape[0]
[docs] def split(self, size: int, shuffle: bool = True, merge_last: bool = False) -> Iterator["Batch"]: length = len(self) assert 1 <= size # size can be greater than length, return whole batch if shuffle: indices = np.random.permutation(length) else: indices = np.arange(length) merge_last = merge_last and length % size > 0 for idx in range(0, length, size): if merge_last and idx + size + size >= length: yield self[indices[idx:]] break yield self[indices[idx:idx + size]]