Support higher MaxConnections & fix Windows errors

Fixes #4, fixes #8, fixes #11, fixes #28, fixes #34, fixes #36, fixes #37

config.ini

@@ -2,11 +2,13 @@
 ; How many seconds to wait for the proxy to make a connection.
 ; The higher the number, the longer the check will take
 ; and the more proxies you get.
-Timeout = 10
+Timeout = 5
 
 ; Maximum concurrent connections.
-; Don't set higher than 900, please.
-MaxConnections = 900
+; Windows supports maximum of 512.
+; On *nix operating systems, this restriction is much looser.
+; The limit on *nix can be seen with the command ulimit -Hn.
+MaxConnections = 512
 
 ; Set to no to sort proxies alphabetically.
 SortBySpeed = yes

proxy_scraper_checker/__main__.py

@@ -11,8 +11,10 @@ from rich.logging import RichHandler
 from .proxy_scraper_checker import ProxyScraperChecker
 
 
-def install_uvloop() -> None:
-    if sys.implementation.name == "cpython" and sys.platform in {
+def set_event_loop_policy() -> None:
+    if sys.platform == "win32":
+        asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
+    elif sys.implementation.name == "cpython" and sys.platform in {
         "darwin",
         "linux",
     }:
@@ -42,7 +44,7 @@ def configure_logging(console: Console) -> None:
 
 
 def main() -> None:
-    install_uvloop()
+    set_event_loop_policy()
 
     console = Console()
     configure_logging(console)

proxy_scraper_checker/proxy_scraper_checker.py

@@ -3,6 +3,8 @@ from __future__ import annotations
 import asyncio
 import logging
 import re
+import resource
+import sys
 from configparser import ConfigParser
 from pathlib import Path
 from random import shuffle
@@ -40,6 +42,25 @@ TProxyScraperChecker = TypeVar(
 )
 
 
+def validate_max_connections(value: int) -> int:
+    if sys.platform != "win32":
+        soft_limit, hard_limit = resource.getrlimit(resource.RLIMIT_NOFILE)
+        if soft_limit < hard_limit:
+            resource.setrlimit(
+                resource.RLIMIT_NOFILE, (hard_limit, hard_limit)
+            )
+    elif value > 512 and isinstance(
+        asyncio.get_event_loop_policy(), asyncio.WindowsSelectorEventLoopPolicy
+    ):
+        logger.warning(
+            "MaxConnections value is too high. "
+            + "Windows supports a maximum of 512. "
+            + "The config value will be ignored and 512 will be used."
+        )
+        return 512
+    return value
+
+
 class ProxyScraperChecker:
     """HTTP, SOCKS4, SOCKS5 proxies scraper and checker."""
 
@@ -135,6 +156,8 @@ class ProxyScraperChecker:
         self.proxies_count = {proto: 0 for proto in self.sources}
         self.cookie_jar = DummyCookieJar()
         self.console = console or Console()
+
+        max_connections = validate_max_connections(max_connections)
         self.sem = asyncio.Semaphore(max_connections)
 
     @classmethod