ytdl-sub/src/ytdl_sub/validators/validators.py
Jesse Bannon f1a2187a17
[FEATURE] Add throttle_protection plugin (#799)
Provides options to make ytdl-sub look more 'human-like' to protect from throttling. For range-based values, a random number will be chosen within the range to avoid sleeps looking scripted.

Usage:
```
    throttle_protection:
      sleep_per_download_s:
        min: 2.2
        max: 10.8
      sleep_per_subscription_s:
        min: 9.0
        max: 14.1
      max_downloads_per_subscription:
        min: 10
        max: 36
      subscription_download_probability: 1.0
```
2023-11-05 08:23:12 -08:00

327 lines
8.9 KiB
Python

import copy
from abc import ABC
from typing import Any
from typing import Dict
from typing import Generic
from typing import List
from typing import Optional
from typing import Type
from typing import TypeVar
from typing import final
from ytdl_sub.utils.exceptions import ValidationException
ValueT = TypeVar("ValueT", bound=object)
ValidationExceptionT = TypeVar("ValidationExceptionT", bound=ValidationException)
ValidatorT = TypeVar("ValidatorT", bound="Validator")
def validation_exception(
name: str,
error_message: str | Exception,
exception_class: Type[ValidationExceptionT] = ValidationException,
) -> ValidationExceptionT:
"""
Parameters
----------
name
Name of the validator
error_message
Error message to include in the ValidationException
exception_class
Class of the exception
Returns
-------
Validation exception with a consistent prefix.
"""
prefix = f"Validation error in {name}: "
return exception_class(f"{prefix}{error_message}")
class Validator(ABC):
"""
Used to validate the value of a python object. This is the 'base' class that will first
check that the value's type matches the expected type. Validators that inherit from this should
perform their validation within the __init__.
"""
# If the value is not this expected type, error
_expected_value_type: Type = object
# When raising an error, call the type this value instead of its python name
_expected_value_type_name: Optional[str] = None
@classmethod
def partial_validate(cls, name: str, value: Any) -> None:
"""
Parameters
----------
name
Name of the validator
value
Value of the validator
"""
_ = cls(name=name, value=value)
def __init__(self, name: str, value: Any):
self._name = name
self._value = copy.deepcopy(value) # Always deep copy to avoid editing references
if not isinstance(self._value, self._expected_value_type):
expected_value_type_name = self._expected_value_type_name or str(
self._expected_value_type
)
raise self._validation_exception(
error_message=f"should be of type {expected_value_type_name}."
)
def _validation_exception(
self,
error_message: str | Exception,
exception_class: Type[ValidationExceptionT] = ValidationException,
) -> ValidationExceptionT:
"""
Parameters
----------
error_message
Error message to include in the ValidationException
Returns
-------
Validation exception with a consistent prefix.
"""
return validation_exception(self._name, error_message, exception_class)
@final
@property
def _root_name(self) -> str:
"""
Returns
-------
"first" from the first.element.of.the.name
"""
return self._name.split(".")[0]
@final
@property
def _leaf_name(self) -> str:
"""
Returns
-------
"first" from the first.element.of.the.name
"""
return self._name.split(".")[-1]
class ValueValidator(Validator, ABC, Generic[ValueT]):
"""
Native type validator that returns the value as-is
"""
@property
def value(self) -> ValueT:
"""
Returns
-------
The value, unmodified
"""
return self._value
class BoolValidator(ValueValidator[bool]):
_expected_value_type: Type = bool
_expected_value_type_name = "boolean"
class StringValidator(ValueValidator[str]):
_expected_value_type = str
_expected_value_type_name = "string"
class FloatValidator(ValueValidator[float]):
_expected_value_type = (int, float)
_expected_value_type_name = "float"
class IntValidator(ValueValidator[int]):
_expected_value_type = int
_expected_value_type_name = "int"
class ProbabilityValidator(FloatValidator):
_expected_value_type_name = "probability"
def __init__(self, name, value):
super().__init__(name, value)
if self.value < 0 or self.value > 1:
raise self._validation_exception("Probabilities must be between 0 and 1.0")
class ListValidator(Validator, ABC, Generic[ValidatorT]):
"""
Validates a list of objects to validate
"""
_expected_value_type = list
_expected_value_type_name = "list"
_inner_list_type: Type[ValidatorT]
def __init__(self, name, value):
# If the value isn't actually a list, but a single value with the same type as the
# _inner_list_type, cast it to a list with a single element
if isinstance(value, self._inner_list_type._expected_value_type):
value = [value]
super().__init__(name, value)
self._list: List[ValidatorT] = [
self._inner_list_type(name=f"{name}.{i+1}", value=val)
for i, val in enumerate(self._value)
]
@property
def list(self) -> List[ValidatorT]:
"""
Returns
-------
The list
"""
return self._list
class StringListValidator(ListValidator[StringValidator]):
_expected_value_type_name = "string list"
_inner_list_type = StringValidator
class DictValidator(Validator):
"""
Validates dictionary-based fields. Errors to them as 'object's since this could be validating
a yaml.
"""
_expected_value_type = dict
_expected_value_type_name = "object"
def __init__(self, name, value):
super().__init__(name, value)
self.__validator_dict: Dict[str, Validator] = {}
@final
@property
def _dict(self) -> dict:
"""
Returns
-------
Dictionary value
"""
return self._value
@final
@property
def _validator_dict(self) -> Dict[str, Validator]:
"""
Returns dict containing names and validators of any keys that were validated.
This allows top-level validators to recursively search a dict validator.
"""
return self.__validator_dict
@final
@property
def _keys(self) -> List[str]:
"""
Returns
-------
Sorted list of dictionary keys
"""
return sorted(list(self._dict.keys()))
@final
def _validate_key(
self,
key: str,
validator: Type[ValidatorT],
default: Optional[Any] = None,
) -> ValidatorT:
"""
Parameters
----------
key
Name of they key in the dict to validate
validator
The validator to use for the key's value
default
If the key's value does not exist, use this value, unless it is None.
Returns
-------
An instance of the specified validator
"""
if key not in self._dict and default is None:
raise self._validation_exception(f"{key} is missing when it should be present.")
validator_name = f"{self._name}.{key}" if self._name else key
validator_instance = validator(
name=validator_name,
value=self._dict.get(key, default),
)
self.__validator_dict[validator_name] = validator_instance
return validator_instance
@final
def _validate_key_if_present(
self,
key: str,
validator: Type[ValidatorT],
default: Optional[Any] = None,
) -> Optional[ValidatorT]:
"""
If the key does not exist in the dict, and no default is provided, return None.
Otherwise, validate the key.
Parameters
----------
key
Name of they key in the dict to validate
validator
The validator to use for the key's value
default
If the key's value does not exist, use this value.
Returns
-------
An instance of the specified validator
"""
# If the key does not exist and default is None, return None
if key not in self._dict and default is None:
return None
# If the key exists but is None (null in YAML) or empty string, return None
if key in self._dict and self._dict[key] in (None, ""):
return None
return self._validate_key(key=key, validator=validator, default=default)
@final
@classmethod
def _partial_validate_key(
cls, name: str, value: Any, key: str, validator: Type[ValidatorT]
) -> None:
value_dict = DictValidator(name=name, value=value)
if key in value_dict._dict:
validator.partial_validate(name=f"{name}.{key}", value=value_dict._dict[key])
class LiteralDictValidator(DictValidator):
"""DictValidator with exposed dict and keys method"""
@property
def dict(self) -> Dict:
"""Returns the entire dict"""
return super()._dict
@property
def keys(self) -> List[str]:
"""Returns a sorted list of the dict's keys"""
return super()._keys