207 lines
8.1 KiB
Python
207 lines
8.1 KiB
Python
# pragma pylint: disable=attribute-defined-outside-init
|
|
|
|
"""
|
|
This module load custom objects
|
|
"""
|
|
import importlib.util
|
|
import inspect
|
|
import logging
|
|
import sys
|
|
from pathlib import Path
|
|
from typing import Any, Dict, Iterator, List, Optional, Tuple, Type, Union
|
|
|
|
from freqtrade.exceptions import OperationalException
|
|
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
class PathModifier:
|
|
def __init__(self, path: Path):
|
|
self.path = path
|
|
|
|
def __enter__(self):
|
|
"""Inject path to allow importing with relative imports."""
|
|
sys.path.insert(0, str(self.path))
|
|
return self
|
|
|
|
def __exit__(self, exc_type, exc_val, exc_tb):
|
|
"""Undo insertion of local path."""
|
|
str_path = str(self.path)
|
|
if str_path in sys.path:
|
|
sys.path.remove(str_path)
|
|
|
|
|
|
class IResolver:
|
|
"""
|
|
This class contains all the logic to load custom classes
|
|
"""
|
|
# Childclasses need to override this
|
|
object_type: Type[Any]
|
|
object_type_str: str
|
|
user_subdir: Optional[str] = None
|
|
initial_search_path: Optional[Path]
|
|
|
|
@classmethod
|
|
def build_search_paths(cls, config: Dict[str, Any], user_subdir: Optional[str] = None,
|
|
extra_dir: Optional[str] = None) -> List[Path]:
|
|
|
|
abs_paths: List[Path] = []
|
|
if cls.initial_search_path:
|
|
abs_paths.append(cls.initial_search_path)
|
|
|
|
if user_subdir:
|
|
abs_paths.insert(0, config['user_data_dir'].joinpath(user_subdir))
|
|
|
|
if extra_dir:
|
|
# Add extra directory to the top of the search paths
|
|
abs_paths.insert(0, Path(extra_dir).resolve())
|
|
|
|
return abs_paths
|
|
|
|
@classmethod
|
|
def _get_valid_object(cls, module_path: Path, object_name: Optional[str],
|
|
enum_failed: bool = False) -> Iterator[Any]:
|
|
"""
|
|
Generator returning objects with matching object_type and object_name in the path given.
|
|
:param module_path: absolute path to the module
|
|
:param object_name: Class name of the object
|
|
:param enum_failed: If True, will return None for modules which fail.
|
|
Otherwise, failing modules are skipped.
|
|
:return: generator containing tuple of matching objects
|
|
Tuple format: [Object, source]
|
|
"""
|
|
|
|
# Generate spec based on absolute path
|
|
# Pass object_name as first argument to have logging print a reasonable name.
|
|
with PathModifier(module_path.parent):
|
|
module_name = module_path.stem or ""
|
|
spec = importlib.util.spec_from_file_location(module_name, str(module_path))
|
|
if not spec:
|
|
return iter([None])
|
|
|
|
module = importlib.util.module_from_spec(spec)
|
|
try:
|
|
spec.loader.exec_module(module) # type: ignore # importlib does not use typehints
|
|
except (ModuleNotFoundError, SyntaxError, ImportError, NameError) as err:
|
|
# Catch errors in case a specific module is not installed
|
|
logger.warning(f"Could not import {module_path} due to '{err}'")
|
|
if enum_failed:
|
|
return iter([None])
|
|
|
|
valid_objects_gen = (
|
|
(obj, inspect.getsource(module)) for
|
|
name, obj in inspect.getmembers(
|
|
module, inspect.isclass) if ((object_name is None or object_name == name)
|
|
and issubclass(obj, cls.object_type)
|
|
and obj is not cls.object_type
|
|
and obj.__module__ == module_name
|
|
)
|
|
)
|
|
# The __module__ check ensures we only use strategies that are defined in this folder.
|
|
return valid_objects_gen
|
|
|
|
@classmethod
|
|
def _search_object(cls, directory: Path, *, object_name: str, add_source: bool = False
|
|
) -> Union[Tuple[Any, Path], Tuple[None, None]]:
|
|
"""
|
|
Search for the objectname in the given directory
|
|
:param directory: relative or absolute directory path
|
|
:param object_name: ClassName of the object to load
|
|
:return: object class
|
|
"""
|
|
logger.debug(f"Searching for {cls.object_type.__name__} {object_name} in '{directory}'")
|
|
for entry in directory.iterdir():
|
|
# Only consider python files
|
|
if entry.suffix != '.py':
|
|
logger.debug('Ignoring %s', entry)
|
|
continue
|
|
if entry.is_symlink() and not entry.is_file():
|
|
logger.debug('Ignoring broken symlink %s', entry)
|
|
continue
|
|
module_path = entry.resolve()
|
|
|
|
obj = next(cls._get_valid_object(module_path, object_name), None)
|
|
|
|
if obj:
|
|
obj[0].__file__ = str(entry)
|
|
if add_source:
|
|
obj[0].__source__ = obj[1]
|
|
return (obj[0], module_path)
|
|
return (None, None)
|
|
|
|
@classmethod
|
|
def _load_object(cls, paths: List[Path], *, object_name: str, add_source: bool = False,
|
|
kwargs: dict = {}) -> Optional[Any]:
|
|
"""
|
|
Try to load object from path list.
|
|
"""
|
|
|
|
for _path in paths:
|
|
try:
|
|
(module, module_path) = cls._search_object(directory=_path,
|
|
object_name=object_name,
|
|
add_source=add_source)
|
|
if module:
|
|
logger.info(
|
|
f"Using resolved {cls.object_type.__name__.lower()[1:]} {object_name} "
|
|
f"from '{module_path}'...")
|
|
return module(**kwargs)
|
|
except FileNotFoundError:
|
|
logger.warning('Path "%s" does not exist.', _path.resolve())
|
|
|
|
return None
|
|
|
|
@classmethod
|
|
def load_object(cls, object_name: str, config: dict, *, kwargs: dict,
|
|
extra_dir: Optional[str] = None) -> Any:
|
|
"""
|
|
Search and loads the specified object as configured in hte child class.
|
|
:param object_name: name of the module to import
|
|
:param config: configuration dictionary
|
|
:param extra_dir: additional directory to search for the given pairlist
|
|
:raises: OperationalException if the class is invalid or does not exist.
|
|
:return: Object instance or None
|
|
"""
|
|
|
|
abs_paths = cls.build_search_paths(config,
|
|
user_subdir=cls.user_subdir,
|
|
extra_dir=extra_dir)
|
|
|
|
found_object = cls._load_object(paths=abs_paths, object_name=object_name,
|
|
kwargs=kwargs)
|
|
if found_object:
|
|
return found_object
|
|
raise OperationalException(
|
|
f"Impossible to load {cls.object_type_str} '{object_name}'. This class does not exist "
|
|
"or contains Python code errors."
|
|
)
|
|
|
|
@classmethod
|
|
def search_all_objects(cls, directory: Path,
|
|
enum_failed: bool) -> List[Dict[str, Any]]:
|
|
"""
|
|
Searches a directory for valid objects
|
|
:param directory: Path to search
|
|
:param enum_failed: If True, will return None for modules which fail.
|
|
Otherwise, failing modules are skipped.
|
|
:return: List of dicts containing 'name', 'class' and 'location' entries
|
|
"""
|
|
logger.debug(f"Searching for {cls.object_type.__name__} '{directory}'")
|
|
objects = []
|
|
for entry in directory.iterdir():
|
|
# Only consider python files
|
|
if entry.suffix != '.py':
|
|
logger.debug('Ignoring %s', entry)
|
|
continue
|
|
module_path = entry.resolve()
|
|
logger.debug(f"Path {module_path}")
|
|
for obj in cls._get_valid_object(module_path, object_name=None,
|
|
enum_failed=enum_failed):
|
|
objects.append(
|
|
{'name': obj[0].__name__ if obj is not None else '',
|
|
'class': obj[0] if obj is not None else None,
|
|
'location': entry,
|
|
})
|
|
return objects
|