1 files changed, 52 insertions, 18 deletions

diff --git a/src/home/util.py b/src/home/util.py
index 93a9d8f..35505bc 100644
--- a/src/home/util.py
+++ b/src/home/util.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import json
 import socket
 import time
@@ -6,17 +8,57 @@ import traceback
 import logging
 import string
 import random
+import re
 
 from enum import Enum
 from datetime import datetime
 from typing import Tuple, Optional, List
 from zlib import adler32
 
-Addr = Tuple[str, int]  # network address type (host, port)
-
 logger = logging.getLogger(__name__)
 
 
+def validate_ipv4_or_hostname(address: str, raise_exception: bool = False) -> bool:
+    if re.match(r'^(\d{1,3}\.){3}\d{1,3}$', address):
+        parts = address.split('.')
+        if all(0 <= int(part) < 256 for part in parts):
+            return True
+        else:
+            if raise_exception:
+                raise ValueError(f"invalid IPv4 address: {address}")
+            return False
+
+    if re.match(r'^[a-zA-Z0-9.-]+$', address):
+        return True
+    else:
+        if raise_exception:
+            raise ValueError(f"invalid hostname: {address}")
+        return False
+
+
+class Addr:
+    host: str
+    port: int
+
+    def __init__(self, host: str, port: int):
+        self.host = host
+        self.port = port
+
+    @staticmethod
+    def fromstring(addr: str) -> Addr:
+        if addr.count(':') != 1:
+            raise ValueError('invalid host:port format')
+
+        host, port = addr.split(':')
+        validate_ipv4_or_hostname(host, raise_exception=True)
+
+        port = int(port)
+        if not 0 <= port <= 65535:
+            raise ValueError(f'invalid port {port}')
+
+        return Addr(host, port)
+
+
 # https://stackoverflow.com/questions/312443/how-do-you-split-a-list-into-evenly-sized-chunks
 def chunks(lst, n):
     """Yield successive n-sized chunks from lst."""
@@ -45,21 +87,6 @@ def ipv4_valid(ip: str) -> bool:
         return False
 
 
-def parse_addr(addr: str) -> Addr:
-    if addr.count(':') != 1:
-        raise ValueError('invalid host:port format')
-
-    host, port = addr.split(':')
-    if not ipv4_valid(host):
-        raise ValueError('invalid ipv4 address')
-
-    port = int(port)
-    if not 0 <= port <= 65535:
-        raise ValueError('invalid port')
-
-    return host, port
-
-
 def strgen(n: int):
     return ''.join(random.choices(string.ascii_letters + string.digits, k=n))
 
@@ -193,4 +220,11 @@ def filesize_fmt(num, suffix="B") -> str:
 
 class HashableEnum(Enum):
     def hash(self) -> int:
-        return adler32(self.name.encode())
\ No newline at end of file
+        return adler32(self.name.encode())
+
+
+def next_tick_gen(freq):
+    t = time.time()
+    while True:
+        t += freq
+        yield max(t - time.time(), 0)
\ No newline at end of file