Files
DECNET/decnet/realism/llm/impl/ollama.py

101 lines
3.4 KiB
Python

"""Ollama subprocess backend.
Shells out to ``ollama run <model>`` with the prompt fed via stdin.
Why subprocess and not the Ollama HTTP API:
* No new dependency (``ollama`` Python lib is optional).
* Works on hosts where Ollama is bound to a unix socket, an unusual TCP
port, or behind a remote-mount layer — `ollama run` resolves all that.
* Same path the operator uses by hand (``ollama run llama3.1``); easier
to debug discrepancies between worker output and a console session.
Cost: per-call process spawn (~50ms on a warm box). Acceptable for
realism tick rates (one body per ~5 minutes per persona by default).
When that cost matters, swap to an HTTP-API backend; the seam is in
:mod:`decnet.realism.llm.factory`.
"""
from __future__ import annotations
import asyncio
import os
import time
from typing import Optional
from decnet.logging import get_logger
from decnet.realism.llm.base import LLMBackend, LLMResult, LLMTimeout
log = get_logger("realism.llm")
_OLLAMA = "ollama"
_DEFAULT_MODEL = os.environ.get("DECNET_REALISM_MODEL", "llama3.1")
_DEFAULT_TIMEOUT = float(os.environ.get("DECNET_REALISM_TIMEOUT", "60"))
class OllamaBackend(LLMBackend):
"""Concrete :class:`LLMBackend` that shells out to ``ollama run``."""
def __init__(
self,
*,
model: Optional[str] = None,
timeout: Optional[float] = None,
) -> None:
self.model = model or _DEFAULT_MODEL
self.timeout = timeout if timeout is not None else _DEFAULT_TIMEOUT
async def generate(self, prompt: str) -> LLMResult:
t0 = time.monotonic()
try:
proc = await asyncio.create_subprocess_exec(
_OLLAMA, "run", self.model,
stdin=asyncio.subprocess.PIPE,
stdout=asyncio.subprocess.PIPE,
stderr=asyncio.subprocess.PIPE,
)
except FileNotFoundError as exc:
latency_ms = int((time.monotonic() - t0) * 1000)
return LLMResult(
success=False,
text="",
model=self.model,
latency_ms=latency_ms,
extra={"rc": 127, "stderr": f"argv[0] not found: {exc}"},
)
try:
stdout, stderr = await asyncio.wait_for(
proc.communicate(prompt.encode("utf-8")),
timeout=self.timeout,
)
except asyncio.TimeoutError as exc:
try:
proc.kill()
except ProcessLookupError:
pass
raise LLMTimeout(
f"ollama run {self.model} exceeded {self.timeout}s"
) from exc
latency_ms = int((time.monotonic() - t0) * 1000)
rc = proc.returncode if proc.returncode is not None else -1
text = stdout.decode("utf-8", "replace")
stderr_s = stderr.decode("utf-8", "replace")
if rc != 0 or not text.strip():
log.warning(
"ollama backend non-zero / empty rc=%d model=%s stderr=%r",
rc, self.model, stderr_s[:200],
)
return LLMResult(
success=False,
text=text,
model=self.model,
latency_ms=latency_ms,
extra={"rc": rc, "stderr": stderr_s.strip()[:256]},
)
return LLMResult(
success=True,
text=text,
model=self.model,
latency_ms=latency_ms,
extra={"rc": rc},
)