mirror of
https://github.com/searxng/searxng
synced 2024-01-01 19:24:07 +01:00
1a11282ab4
call Python directly with -S and -I parameters to skip loading of the standard library and the SearXNG module. The actual calculator is moved to a standalone script: calculator_process.py
107 lines
3.8 KiB
Python
107 lines
3.8 KiB
Python
# SPDX-License-Identifier: AGPL-3.0-or-later
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"""Calculate mathematical expressions using ack#eval
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"""
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import re
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import sys
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import subprocess
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from pathlib import Path
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import flask
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import babel
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from flask_babel import gettext
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from searx.plugins import logger
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name = "Basic Calculator"
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description = gettext("Calculate mathematical expressions via the search bar")
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default_on = True
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preference_section = 'general'
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plugin_id = 'calculator'
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logger = logger.getChild(plugin_id)
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def call_calculator(query_py_formatted, timeout):
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calculator_process_py_path = Path(__file__).parent.absolute() / "calculator_process.py"
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# see https://docs.python.org/3/using/cmdline.html
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# -S Disable the import of the module site and the site-dependent manipulations
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# of sys.path that it entails. Also disable these manipulations if site is
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# explicitly imported later (call site.main() if you want them to be triggered).
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# -I Run Python in isolated mode. This also implies -E, -P and -s options.
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# -E Ignore all PYTHON* environment variables, e.g. PYTHONPATH and PYTHONHOME, that might be set.
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# -P Don’t prepend a potentially unsafe path to sys.path
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# -s Don’t add the user site-packages directory to sys.path.
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process = subprocess.Popen( # pylint: disable=R1732
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[sys.executable, "-S", "-I", calculator_process_py_path, query_py_formatted],
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stdout=subprocess.PIPE,
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stderr=subprocess.PIPE,
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text=True,
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)
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try:
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stdout, stderr = process.communicate(timeout=timeout)
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if process.returncode == 0 and not stderr:
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return stdout
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logger.debug("calculator exited with stderr %s", stderr)
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return None
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except subprocess.TimeoutExpired:
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process.terminate()
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try:
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# Give the process a grace period to terminate
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process.communicate(timeout=2)
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except subprocess.TimeoutExpired:
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# Forcefully kill the process
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process.kill()
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process.communicate()
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logger.debug("calculator terminated after timeout")
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# Capture any remaining output
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return None
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finally:
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# Ensure the process is fully cleaned up
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if process.poll() is None: # If still running
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process.kill()
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process.communicate()
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def post_search(_request, search):
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# only show the result of the expression on the first page
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if search.search_query.pageno > 1:
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return True
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query = search.search_query.query
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# in order to avoid DoS attacks with long expressions, ignore long expressions
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if len(query) > 100:
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return True
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# replace commonly used math operators with their proper Python operator
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query = query.replace("x", "*").replace(":", "/")
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# use UI language
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ui_locale = babel.Locale.parse(flask.request.preferences.get_value('locale'), sep='-')
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# parse the number system in a localized way
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def _decimal(match: re.Match) -> str:
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val = match.string[match.start() : match.end()]
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val = babel.numbers.parse_decimal(val, ui_locale, numbering_system="latn")
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return str(val)
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decimal = ui_locale.number_symbols["latn"]["decimal"]
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group = ui_locale.number_symbols["latn"]["group"]
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query = re.sub(f"[0-9]+[{decimal}|{group}][0-9]+[{decimal}|{group}]?[0-9]?", _decimal, query)
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# only numbers and math operators are accepted
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if any(str.isalpha(c) for c in query):
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return True
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# in python, powers are calculated via **
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query_py_formatted = query.replace("^", "**")
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# Prevent the runtime from being longer than 50 ms
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result = call_calculator(query_py_formatted, 0.05)
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if result is None or result == "":
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return True
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result = babel.numbers.format_decimal(result, locale=ui_locale)
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search.result_container.answers['calculate'] = {'answer': f"{search.search_query.query} = {result}"}
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return True
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