h3cx
482c093f38
Isolated the JsonServer to server.py inside protocols/json Added specific errors for server startup timeout and server startup failed Refactored errors for Core to CoreError generic and refactored StateError to CoreStateMismatchError derived from CoreError
28 lines
847 B
Python
28 lines
847 B
Python
import socket
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def find_available_port(
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preferred_port: int | None = None,
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host: str = "127.0.0.1",
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) -> int:
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"""Return an available TCP port on the given host.
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The preferred port is returned when available. Otherwise, the operating
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system selects an available ephemeral port.
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"""
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if preferred_port is not None:
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if not 1 <= preferred_port <= 65535:
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raise ValueError("preferred_port must be between 1 and 65535")
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with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
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try:
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sock.bind((host, preferred_port))
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except OSError:
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pass
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else:
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return preferred_port
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with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
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sock.bind((host, 0))
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return int(sock.getsockname()[1])
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