feat: add pre-compaction memory flush

src/auto-reply/reply/memory-flush.ts

@@ -0,0 +1,103 @@
+import { lookupContextTokens } from "../../agents/context.js";
+import { DEFAULT_CONTEXT_TOKENS } from "../../agents/defaults.js";
+import { DEFAULT_PI_COMPACTION_RESERVE_TOKENS_FLOOR } from "../../agents/pi-settings.js";
+import type { ClawdbotConfig } from "../../config/config.js";
+import type { SessionEntry } from "../../config/sessions.js";
+import { SILENT_REPLY_TOKEN } from "../tokens.js";
+
+export const DEFAULT_MEMORY_FLUSH_SOFT_TOKENS = 4000;
+
+export const DEFAULT_MEMORY_FLUSH_PROMPT = [
+  "Pre-compaction memory flush.",
+  "Store durable memories now (use memory/YYYY-MM-DD.md; create memory/ if needed).",
+  `If nothing to store, reply with ${SILENT_REPLY_TOKEN}.`,
+].join(" ");
+
+export const DEFAULT_MEMORY_FLUSH_SYSTEM_PROMPT = [
+  "Pre-compaction memory flush turn.",
+  "The session is near auto-compaction; capture durable memories to disk.",
+  `You may reply, but usually ${SILENT_REPLY_TOKEN} is correct.`,
+].join(" ");
+
+export type MemoryFlushSettings = {
+  enabled: boolean;
+  softThresholdTokens: number;
+  prompt: string;
+  systemPrompt: string;
+  reserveTokensFloor: number;
+};
+
+const normalizeNonNegativeInt = (value: unknown): number | null => {
+  if (typeof value !== "number" || !Number.isFinite(value)) return null;
+  const int = Math.floor(value);
+  return int >= 0 ? int : null;
+};
+
+export function resolveMemoryFlushSettings(
+  cfg?: ClawdbotConfig,
+): MemoryFlushSettings | null {
+  const defaults = cfg?.agents?.defaults?.compaction?.memoryFlush;
+  const enabled = defaults?.enabled ?? true;
+  if (!enabled) return null;
+  const softThresholdTokens =
+    normalizeNonNegativeInt(defaults?.softThresholdTokens) ??
+    DEFAULT_MEMORY_FLUSH_SOFT_TOKENS;
+  const prompt = defaults?.prompt?.trim() || DEFAULT_MEMORY_FLUSH_PROMPT;
+  const systemPrompt =
+    defaults?.systemPrompt?.trim() || DEFAULT_MEMORY_FLUSH_SYSTEM_PROMPT;
+  const reserveTokensFloor =
+    normalizeNonNegativeInt(
+      cfg?.agents?.defaults?.compaction?.reserveTokensFloor,
+    ) ?? DEFAULT_PI_COMPACTION_RESERVE_TOKENS_FLOOR;
+
+  return {
+    enabled,
+    softThresholdTokens,
+    prompt: ensureNoReplyHint(prompt),
+    systemPrompt: ensureNoReplyHint(systemPrompt),
+    reserveTokensFloor,
+  };
+}
+
+function ensureNoReplyHint(text: string): string {
+  if (text.includes(SILENT_REPLY_TOKEN)) return text;
+  return `${text}\n\nIf no user-visible reply is needed, start with ${SILENT_REPLY_TOKEN}.`;
+}
+
+export function resolveMemoryFlushContextWindowTokens(params: {
+  modelId?: string;
+  agentCfgContextTokens?: number;
+}): number {
+  return (
+    lookupContextTokens(params.modelId) ??
+    params.agentCfgContextTokens ??
+    DEFAULT_CONTEXT_TOKENS
+  );
+}
+
+export function shouldRunMemoryFlush(params: {
+  entry?: Pick<
+    SessionEntry,
+    "totalTokens" | "compactionCount" | "memoryFlushCompactionCount"
+  >;
+  contextWindowTokens: number;
+  reserveTokensFloor: number;
+  softThresholdTokens: number;
+}): boolean {
+  const totalTokens = params.entry?.totalTokens;
+  if (!totalTokens || totalTokens <= 0) return false;
+  const contextWindow = Math.max(1, Math.floor(params.contextWindowTokens));
+  const reserveTokens = Math.max(0, Math.floor(params.reserveTokensFloor));
+  const softThreshold = Math.max(0, Math.floor(params.softThresholdTokens));
+  const threshold = Math.max(0, contextWindow - reserveTokens - softThreshold);
+  if (threshold <= 0) return false;
+  if (totalTokens < threshold) return false;
+
+  const compactionCount = params.entry?.compactionCount ?? 0;
+  const lastFlushAt = params.entry?.memoryFlushCompactionCount;
+  if (typeof lastFlushAt === "number" && lastFlushAt === compactionCount) {
+    return false;
+  }
+
+  return true;
+}