feat: add Pi process and RPC foundation

This commit is contained in:
2026-08-22 20:05:59 +08:00
parent b6f693048d
commit 9a31dacb2a
14 changed files with 1955 additions and 26 deletions

View File

@@ -0,0 +1,268 @@
import type { Writable } from 'node:stream';
import { PiProcessError } from './process-errors';
export type PiRpcCommand = {
type: string;
[key: string]: unknown;
};
export type PiRpcResponse<T = unknown> = {
type: 'response';
id: string;
command?: string;
success: boolean;
data?: T;
error?: string;
};
export type PiRpcEvent = Record<string, unknown> & { type: string };
export type PiRpcRetryPolicy = 'none' | 'read-only-once';
export type PiRpcRequestOptions = {
signal?: AbortSignal;
timeoutMs?: number;
retry?: PiRpcRetryPolicy;
};
type PendingRequest = {
commandType: string;
resolve(response: PiRpcResponse): void;
reject(error: PiProcessError): void;
cancel(): void;
};
type PiRpcClientOptions = {
generation: number;
defaultTimeoutMs?: number;
idPrefix?: string;
onEventListenerError?(error: unknown): void;
};
const READ_ONLY_COMMANDS = new Set([
'get_available_models',
'get_available_thinking_levels',
'get_commands',
'get_entries',
'get_fork_messages',
'get_last_assistant_text',
'get_messages',
'get_session_stats',
'get_state',
'get_tree',
]);
function recordValue(value: unknown): value is Record<string, unknown> {
return Boolean(value) && typeof value === 'object' && !Array.isArray(value);
}
function responseValue(value: Record<string, unknown>): value is PiRpcResponse {
return value.type === 'response'
&& typeof value.id === 'string'
&& typeof value.success === 'boolean';
}
export class PiRpcClient {
private readonly writable: Writable;
private readonly generation: number;
private readonly defaultTimeoutMs: number;
private readonly idPrefix: string;
private readonly onEventListenerError: ((error: unknown) => void) | undefined;
private readonly pending = new Map<string, PendingRequest>();
private readonly retiredIds = new Set<string>();
private readonly listeners = new Set<(event: PiRpcEvent) => void>();
private sequence = 0;
private invalidated: PiProcessError | null = null;
constructor(writable: Writable, options: PiRpcClientOptions) {
if (!Number.isSafeInteger(options.generation) || options.generation <= 0) {
throw new Error('generation must be a positive safe integer');
}
const defaultTimeoutMs = options.defaultTimeoutMs ?? 10_000;
if (!Number.isSafeInteger(defaultTimeoutMs) || defaultTimeoutMs <= 0) {
throw new Error('defaultTimeoutMs must be a positive safe integer');
}
this.writable = writable;
this.generation = options.generation;
this.defaultTimeoutMs = defaultTimeoutMs;
this.idPrefix = options.idPrefix ?? 'makelore';
this.onEventListenerError = options.onEventListenerError;
this.writable.on('error', (error) => {
this.invalidate(new PiProcessError('PI_RPC_WRITE_FAILED', 'Pi RPC stdin failed', {
cause: error,
generation: this.generation,
}));
});
}
get pendingCount(): number {
return this.pending.size;
}
subscribe(listener: (event: PiRpcEvent) => void): () => void {
this.listeners.add(listener);
return () => this.listeners.delete(listener);
}
async request<T = unknown>(
command: PiRpcCommand,
options: PiRpcRequestOptions = {},
): Promise<PiRpcResponse<T>> {
if (!command.type) throw new Error('Pi RPC command type is required');
const retry = options.retry ?? 'none';
if (retry === 'read-only-once' && !READ_ONLY_COMMANDS.has(command.type)) {
throw new Error(`Pi RPC ${command.type} is not a retryable read-only command`);
}
const attempts = retry === 'read-only-once' ? 2 : 1;
let lastError: unknown;
for (let attempt = 0; attempt < attempts; attempt += 1) {
try {
return await this.requestOnce<T>(command, options);
} catch (error) {
lastError = error;
if (!(error instanceof PiProcessError) || error.code !== 'PI_RPC_TIMEOUT') throw error;
if (this.invalidated || options.signal?.aborted) throw error;
}
}
throw lastError;
}
accept(value: unknown): void {
if (!recordValue(value) || typeof value.type !== 'string') {
throw new PiProcessError('PI_RPC_PROTOCOL_ERROR', 'Pi RPC record must be an object with a type');
}
if (value.type === 'response') {
if (!responseValue(value)) {
throw new PiProcessError('PI_RPC_PROTOCOL_ERROR', 'Pi RPC response shape is invalid');
}
if (this.retiredIds.delete(value.id)) return;
const pending = this.pending.get(value.id);
if (!pending) {
throw new PiProcessError('PI_RPC_PROTOCOL_ERROR', `Pi RPC response used unknown id ${value.id}`);
}
pending.cancel();
this.pending.delete(value.id);
if (value.success) pending.resolve(value);
else {
pending.reject(new PiProcessError(
'PI_RPC_RESPONSE_ERROR',
`Pi RPC ${value.command ?? pending.commandType} failed: ${value.error ?? 'unknown error'}`,
{ generation: this.generation },
));
}
return;
}
for (const listener of this.listeners) {
try {
listener(value as PiRpcEvent);
} catch (error) {
try {
this.onEventListenerError?.(error);
} catch {
// Diagnostics must not affect transport state.
}
}
}
}
invalidate(error: PiProcessError): void {
if (this.invalidated) return;
this.invalidated = error;
for (const [id, pending] of this.pending) {
pending.cancel();
this.retire(id);
pending.reject(error);
}
this.pending.clear();
}
private async requestOnce<T>(
command: PiRpcCommand,
options: PiRpcRequestOptions,
): Promise<PiRpcResponse<T>> {
if (this.invalidated) throw this.invalidated;
if (options.signal?.aborted) {
throw new PiProcessError('PI_RPC_ABORTED', `Pi RPC ${command.type} was aborted`, {
generation: this.generation,
});
}
const timeoutMs = options.timeoutMs ?? this.defaultTimeoutMs;
if (!Number.isSafeInteger(timeoutMs) || timeoutMs <= 0) {
throw new Error('timeoutMs must be a positive safe integer');
}
const id = `${this.idPrefix}-${this.generation}-${++this.sequence}`;
const response = new Promise<PiRpcResponse<T>>((resolve, reject) => {
const timeout = setTimeout(() => {
this.pending.delete(id);
this.retire(id);
reject(new PiProcessError(
'PI_RPC_TIMEOUT',
`Pi RPC ${command.type} timed out after ${timeoutMs}ms`,
{ generation: this.generation },
));
}, timeoutMs);
const abort = (): void => {
this.pending.delete(id);
this.retire(id);
clearTimeout(timeout);
reject(new PiProcessError('PI_RPC_ABORTED', `Pi RPC ${command.type} was aborted`, {
generation: this.generation,
}));
};
options.signal?.addEventListener('abort', abort, { once: true });
this.pending.set(id, {
commandType: command.type,
resolve: (value) => resolve(value as PiRpcResponse<T>),
reject,
cancel: () => {
clearTimeout(timeout);
options.signal?.removeEventListener('abort', abort);
},
});
});
const write = this.write(`${JSON.stringify({ ...command, id })}\n`).catch((error) => {
throw new PiProcessError('PI_RPC_WRITE_FAILED', `Could not write Pi RPC ${command.type}`, {
cause: error,
generation: this.generation,
});
});
try {
const [, record] = await Promise.all([write, response]);
return record;
} catch (error) {
const pending = this.pending.get(id);
if (pending) {
pending.cancel();
this.pending.delete(id);
this.retire(id);
pending.reject(error instanceof PiProcessError
? error
: new PiProcessError('PI_RPC_WRITE_FAILED', `Could not write Pi RPC ${command.type}`, {
cause: error,
generation: this.generation,
}));
}
throw error;
}
}
private write(line: string): Promise<void> {
return new Promise((resolve, reject) => {
this.writable.write(line, (error?: Error | null) => {
if (error) reject(error);
else resolve();
});
});
}
private retire(id: string): void {
this.retiredIds.add(id);
if (this.retiredIds.size <= 256) return;
const oldest = this.retiredIds.values().next().value as string | undefined;
if (oldest) this.retiredIds.delete(oldest);
}
}