magicciv/tooling/rl-self-play/harness_client.py
Natalie ad108810dd feat(@projects/@magic-civilization): add rl-self-play harness and Claude player integration
Co-Authored-By: Lilith Autocommit <noreply@atlilith.com>
2026-05-17 03:51:07 -07:00

151 lines
5.1 KiB
Python

"""Reusable JSON-Lines client for `scripts/player-api-server.sh`.
One client = one subprocess = one game. The Gymnasium env in
`magic_civ_env.py` owns one of these per `reset()` cycle, and the
evaluator owns one per evaluation episode. Both share the same
protocol; pulling it out here lets them stay in sync with the wire
contract documented in `src/game/engine/docs/PLAYER_API.md`.
Strong types throughout — no string-typed errors leaking up from the
harness. Anything off-protocol raises `HarnessError`.
"""
from __future__ import annotations
import json
import os
import subprocess
from dataclasses import dataclass
from pathlib import Path
from typing import Any
REPO_ROOT = Path(__file__).resolve().parents[2]
HARNESS_SCRIPT = REPO_ROOT / "scripts" / "player-api-server.sh"
# Max lines we will read while looking for a matching response before
# giving up. Each harness response sits behind 0..N async notifications,
# so we need a buffer — 5000 is generous enough that even a busy turn
# with hundreds of `unit_moved`/`turn_started` notifications won't trip
# it, while still bounded so a wedged harness can't hang the trainer.
MAX_LINES_PER_RESPONSE = 5000
class HarnessError(RuntimeError):
"""Raised when the harness violates the protocol or dies unexpectedly."""
@dataclass(frozen=True, slots=True)
class HarnessConfig:
"""Per-episode harness configuration. Mirrors the env-var contract in
`scripts/player-api-server.sh` so callers can override any axis without
knowing the env-var spelling."""
seed: int = 42
players: int = 2
player_slot: int = 0
map_size: str = "duel"
map_type: str = "continents"
omniscient: bool = False
timeout_sec: int = 60
def to_env(self) -> dict[str, str]:
return {
"CP_SEED": str(self.seed),
"CP_PLAYERS": str(self.players),
"CP_PLAYER_SLOT": str(self.player_slot),
"CP_MAP_SIZE": self.map_size,
"CP_MAP_TYPE": self.map_type,
"CP_OMNISCIENT": "1" if self.omniscient else "0",
"CP_TIMEOUT_SEC": str(self.timeout_sec),
}
class HarnessClient:
"""One running harness instance. Cheap to construct (sub-second on
macOS once Godot's class cache is warm); destroy + recreate on each
Gym `reset()` so episodes have independent simulator state."""
def __init__(self, config: HarnessConfig | None = None) -> None:
self._config = config or HarnessConfig()
env = {**os.environ, **self._config.to_env()}
self._proc = subprocess.Popen(
["bash", str(HARNESS_SCRIPT)],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.DEVNULL,
cwd=str(REPO_ROOT),
text=True,
bufsize=1,
env=env,
)
self._next_id = 1
self._closed = False
@property
def config(self) -> HarnessConfig:
return self._config
def _send(self, msg: dict[str, Any]) -> dict[str, Any]:
if self._closed:
raise HarnessError("harness already closed")
msg["id"] = self._next_id
self._next_id += 1
assert self._proc.stdin is not None and self._proc.stdout is not None
self._proc.stdin.write(json.dumps(msg) + "\n")
self._proc.stdin.flush()
for _ in range(MAX_LINES_PER_RESPONSE):
line = self._proc.stdout.readline()
if not line:
self._closed = True
raise HarnessError(
f"harness stdout EOF while waiting for id={msg['id']}"
)
try:
obj = json.loads(line)
except json.JSONDecodeError:
# Notifications without an id, or stray stderr that landed
# on stdout — skip and keep reading.
continue
if obj.get("id") == msg["id"]:
return obj
raise HarnessError(
f"no correlated response for id={msg['id']} within {MAX_LINES_PER_RESPONSE} lines"
)
def view(self) -> dict[str, Any]:
r = self._send({"type": "view"})
if not r.get("ok"):
raise HarnessError(f"view failed: {r.get('error')}")
return r["view"]
def act(self, action: dict[str, Any]) -> dict[str, Any]:
r = self._send({"type": "act", "action": action})
if not r.get("ok"):
err = r.get("error", {})
raise HarnessError(
f"act({action.get('type')!r}) failed: "
f"{err.get('code')}: {err.get('message')}"
)
return r
def end_turn(self) -> dict[str, Any]:
return self.act({"type": "end_turn"})
def shutdown(self) -> None:
if self._closed:
return
self._closed = True
try:
self._send({"type": "shutdown"})
except HarnessError:
pass
try:
self._proc.wait(timeout=5)
except subprocess.TimeoutExpired:
self._proc.kill()
self._proc.wait(timeout=2)
def __enter__(self) -> HarnessClient:
return self
def __exit__(self, *exc: object) -> None:
self.shutdown()