pointers.py/src/pointers/stack_pointer.py at master · ZeroIntensity/pointers.py · GitHub

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from typing import Any, Callable, Optional, TypeVar

from _pointers import run_stack_callback

from .base_pointers import BaseAllocatedPointer, IterDereferencable

from .util import handle

__all__ = ("StackAllocatedPointer", "acquire_stack_alloc", "stack_alloc")

T = TypeVar("T")

A = TypeVar("A", bound=BaseAllocatedPointer)

class StackAllocatedPointer(IterDereferencable[T], BaseAllocatedPointer[T]):

"""Pointer to memory allocated on the stack."""

def __init__(

self,

address: int,

size: int,

assigned: bool = False,

) -> None:

"""

Args:

address: Address of the allocated memory.

size: Size of the allocated memory.

assigned: Whether an object is currently inside the memory.

"""

self._address = address

self._size = size

self._freed = False

self._assigned = assigned

@property

def freed(self) -> bool:

return self._freed

@freed.setter

def freed(self, value: bool) -> None:

self._freed = value

@property

def address(self) -> Optional[int]:

return self._address

@address.setter

def address(self, value: int) -> None:

self._address = value

def __repr__(self) -> str:

return f"StackAllocatedPointer(address={self.address}, size={self.size})" # noqa

def __add__(self, amount: int):

return StackAllocatedPointer(

self.ensure() + amount,

self.size,

self.assigned,

)

def __sub__(self, amount: int):

return StackAllocatedPointer(

self.ensure() - amount,

self.size,

self.assigned,

)

def free(self) -> None:

raise ValueError(

"pointers to items on the stack may not be freed dynamically",

)

@handle

def stack_alloc(

size: int,

) -> Callable[

[Callable[[StackAllocatedPointer[Any]], T]], Callable[[], T]

]: # noqa

"""Get a callback with a pointer to stack allocated memory.

This function **is not** run automatically.

For that purpose, use `acquire_stack_alloc`.

Args:

size: Size of the allocation

"""

def decorator(

func: Callable[[StackAllocatedPointer[Any]], T],

) -> Callable[[], T]:

def wrapper():

return run_stack_callback(size, StackAllocatedPointer, func)

return wrapper

return decorator

def acquire_stack_alloc(

size: int,

) -> Callable[[Callable[[StackAllocatedPointer[Any]], T]], T]:

"""Execute a callback with a pointer to stack allocated memory.

Args:

size: Size of the allocation

"""

def decorator(func: Callable[[StackAllocatedPointer[Any]], T]) -> T:

def wrapper():

return run_stack_callback(size, StackAllocatedPointer, func)

return wrapper()

return decorator

pointers.py/src/pointers/stack_pointer.py at master · ZeroIntensity/pointers.py · GitHub

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