Files
niri-ai-sidebar/ollama_client.py

144 lines
4.8 KiB
Python

"""Client utilities for interacting with the Ollama API."""
from __future__ import annotations
from typing import Any, Dict, Iterable, Iterator
try: # pragma: no cover - optional dependency may not be installed in CI
import ollama
except ImportError: # pragma: no cover - fallback path for environments without Ollama
ollama = None # type: ignore[assignment]
class OllamaClientError(RuntimeError):
"""Base exception raised when Ollama operations fail."""
class OllamaUnavailableError(OllamaClientError):
"""Raised when the Ollama Python SDK is not available."""
class OllamaClient:
"""Thin wrapper around the Ollama Python SDK with graceful degradation."""
def __init__(self, host: str | None = None) -> None:
self._host = host
self._client = None
self._cached_models: list[str] | None = None
if ollama is None:
return
if host and hasattr(ollama, "Client"):
self._client = ollama.Client(host=host) # type: ignore[call-arg]
# ------------------------------------------------------------------ helpers
@property
def is_available(self) -> bool:
return ollama is not None
@property
def default_model(self) -> str | None:
models = self.list_models()
return models[0] if models else None
def list_models(self, force_refresh: bool = False) -> list[str]:
"""Return the available model names, caching the result for quick reuse."""
if not self.is_available:
return []
if self._cached_models is not None and not force_refresh:
return list(self._cached_models)
try:
response = self._call_sdk("list") # type: ignore[arg-type]
except OllamaClientError:
return []
models: list[str] = []
for item in response.get("models", []): # type: ignore[assignment]
name = item.get("name") or item.get("model")
if name:
models.append(name)
self._cached_models = models
return list(models)
# ------------------------------------------------------------------ chat APIs
def chat(
self,
*,
model: str,
messages: Iterable[Dict[str, str]],
) -> dict[str, str] | None:
"""Execute a blocking chat call against Ollama."""
if not self.is_available:
return {
"role": "assistant",
"content": "Ollama SDK is not installed; install `ollama` to enable responses.",
}
try:
result = self._call_sdk(
"chat",
model=model,
messages=list(messages),
stream=False,
)
except OllamaClientError as exc:
return {
"role": "assistant",
"content": f"Unable to reach Ollama: {exc}",
}
message = result.get("message") if isinstance(result, dict) else None
if not message:
return {"role": "assistant", "content": ""}
role = message.get("role") or "assistant"
content = message.get("content") or ""
return {"role": role, "content": content}
def stream_chat(
self, *, model: str, messages: Iterable[Dict[str, str]]
) -> Iterator[dict[str, Any]]:
"""Placeholder that exposes the streaming API for future UI hooks."""
if not self.is_available:
raise OllamaUnavailableError(
"Streaming requires the Ollama Python SDK to be installed."
)
try:
stream = self._call_sdk(
"chat",
model=model,
messages=list(messages),
stream=True,
)
except OllamaClientError as exc:
raise OllamaClientError(f"Failed to start streaming chat: {exc}") from exc
if not hasattr(stream, "__iter__"):
raise OllamaClientError("Ollama returned a non-iterable stream response.")
return iter(stream)
# ------------------------------------------------------------------ internals
def _call_sdk(self, method: str, *args: Any, **kwargs: Any) -> Any:
if not self.is_available:
raise OllamaUnavailableError(
"Ollama Python SDK is not available in the environment."
)
target = self._client if self._client is not None else ollama
if target is None or not hasattr(target, method):
raise OllamaClientError(
f"Ollama SDK does not expose method '{method}'. Install or update the SDK."
)
func = getattr(target, method)
try:
return func(*args, **kwargs)
except Exception as exc: # pragma: no cover - network errors depend on runtime
raise OllamaClientError(str(exc)) from exc