cache.ts

 1import { appendFile, mkdir, readFile } from "node:fs/promises";
 2import { dirname } from "node:path";
 3import { POLICY_VERSION } from "./normalize";
 4import type { CacheEntry, Decision, DecisionCache } from "./types";
 5
 6type StoredCacheEntry = CacheEntry & {
 7  policyVersion: number;
 8};
 9
10export function createJsonlDecisionCache(file: string): DecisionCache {
11  return {
12    async lookup(key: string): Promise<Decision | undefined> {
13      try {
14        const content = await readFile(file, "utf8");
15        for (const line of content.split("\n")) {
16          if (!line) continue;
17          try {
18            const entry = JSON.parse(line) as StoredCacheEntry;
19            if (entry.key === key && entry.policyVersion === POLICY_VERSION) return entry.decision;
20          } catch {}
21        }
22      } catch {}
23      return undefined;
24    },
25    async write(entry: CacheEntry): Promise<void> {
26      try {
27        await mkdir(dirname(file), { recursive: true });
28        const stored: StoredCacheEntry = { ...entry, policyVersion: POLICY_VERSION };
29        await appendFile(file, `${JSON.stringify(stored)}\n`);
30      } catch {}
31    },
32  };
33}
34
35export const disabledDecisionCache: DecisionCache = {
36  lookup: async () => undefined,
37  write: async () => {},
38};