Files
chat/src/drivers/ollama.ts
T
2026-09-21 13:36:25 +02:00

112 lines
4.2 KiB
TypeScript

import { config } from "../config.ts";
import { driverLog, fmtBytes, fmtMs } from "./log.ts";
import type { ChatMessage, ChatOptions, DriverModel, LLMDriver } from "./types.ts";
interface OllamaTag {
name: string;
}
/** Local LLM via Ollama. Priority #1. */
export class OllamaDriver implements LLMDriver {
readonly name = "ollama";
readonly enabled: boolean;
constructor(public readonly host: string = config.ollamaHost, enabled = config.ollamaEnabled) {
this.host = host.replace(/\/$/, "");
this.enabled = enabled;
}
async listModels(): Promise<DriverModel[]> {
const t0 = Date.now();
const res = await fetch(`${this.host}/api/tags`, { signal: AbortSignal.timeout(8000) });
if (!res.ok) {
driverLog(this.name, `listModels ERROR: /api/tags -> ${res.status} (${fmtMs(Date.now() - t0)})`);
throw new Error(`ollama /api/tags failed: ${res.status}`);
}
const data = (await res.json()) as { models?: OllamaTag[] };
const models = data.models ?? [];
driverLog(this.name, `listModels -> ${models.length} model(s) [${models.map((m) => m.name).join(", ")}] (${fmtMs(Date.now() - t0)})`);
return models.map((m) => ({
id: `ollama:${m.name}`,
name: m.name,
driver: "ollama",
label: m.name,
}));
}
async chat(messages: ChatMessage[], opts: ChatOptions): Promise<string> {
let out = "";
for await (const t of this.chatStream(messages, opts)) out += t;
return out;
}
async *chatStream(messages: ChatMessage[], opts: ChatOptions): AsyncGenerator<string, void, void> {
const t0 = Date.now();
driverLog(this.name, `chat model=${opts.model} messages=${messages.length} stream=open`);
const res = await fetch(`${this.host}/api/chat`, {
method: "POST",
headers: { "Content-Type": "application/json" },
body: JSON.stringify({ model: opts.model, messages, stream: true }),
signal: opts.signal,
});
if (!res.ok || !res.body) {
const text = await res.text().catch(() => "");
driverLog(this.name, `chat model=${opts.model} ERROR: upstream ${res.status} ${text.slice(0, 120)}`);
throw new Error(`ollama chat failed (${res.status}): ${text.slice(0, 300)}`);
}
const reader = res.body.getReader();
const decoder = new TextDecoder();
let buf = "";
let chunks = 0;
let chars = 0;
let status = "done";
try {
while (true) {
const { done, value } = await reader.read();
if (done) break;
buf += decoder.decode(value, { stream: true });
const lines = buf.split("\n");
buf = lines.pop() ?? "";
for (const line of lines) {
const trimmed = line.trim();
if (!trimmed) continue;
try {
const obj = JSON.parse(trimmed) as { message?: { content?: string }; error?: string; done?: boolean };
if (obj.error) throw new Error(`ollama error: ${obj.error}`);
const token = obj.message?.content ?? "";
if (token) {
chunks++;
chars += token.length;
opts.onToken?.(token);
yield token;
}
if (obj.done) {
driverLog(this.name, `chat model=${opts.model} done: ${chunks} chunks, ${fmtBytes(chars)} in ${fmtMs(Date.now() - t0)}`);
return;
}
} catch (e) {
if (e instanceof SyntaxError) continue; // partial line, ignore
throw e;
}
}
}
driverLog(this.name, `chat model=${opts.model} upstream closed: ${chunks} chunks, ${fmtBytes(chars)} in ${fmtMs(Date.now() - t0)}`);
} catch (e) {
status = (e as Error).name === "AbortError" ? "aborted-by-caller" : `ERROR: ${(e as Error).message}`;
throw e;
} finally {
// Stop the upstream generation when the consumer goes away
// (client disconnect) instead of leaking it in the background.
try {
await reader.cancel();
} catch {
// already closed / consumed — fine
}
reader.releaseLock();
if (status !== "done") {
driverLog(this.name, `chat model=${opts.model} ${status} after ${chunks} chunks, ${fmtBytes(chars)} in ${fmtMs(Date.now() - t0)}`);
}
}
}
}