/**
* Project Cache - Layer 3: Optimization
* Intelligent caching with invalidation based on git HEAD + file mtimes
*/
import { promises as fs } from 'fs';
import { join } from 'path';
import simpleGit from 'simple-git';
interface CacheEntry<T> {
data: T;
gitHead: string;
manifestMtime: number;
timestamp: number;
}
interface CacheKey {
projectPath: string;
gitHead: string;
manifestMtime: number;
}
export class ProjectCache {
private cache = new Map<string, CacheEntry<any>>();
private ttlMs = 60 * 60 * 1000; // 1 hour
/**
* Get cached data if valid
*/
async get<T>(projectPath: string): Promise<T | null> {
const key = await this.getCacheKey(projectPath);
if (!key) return null;
const cacheKey = this.buildKey(key);
const entry = this.cache.get(cacheKey);
if (!entry) return null;
// Check TTL
if (Date.now() - entry.timestamp > this.ttlMs) {
this.cache.delete(cacheKey);
return null;
}
// Validate cache still valid
if (entry.gitHead !== key.gitHead || entry.manifestMtime !== key.manifestMtime) {
this.cache.delete(cacheKey);
return null;
}
return entry.data as T;
}
/**
* Store data in cache
*/
async set<T>(projectPath: string, data: T): Promise<void> {
const key = await this.getCacheKey(projectPath);
if (!key) return;
const cacheKey = this.buildKey(key);
this.cache.set(cacheKey, {
data,
gitHead: key.gitHead,
manifestMtime: key.manifestMtime,
timestamp: Date.now()
});
}
/**
* Invalidate cache for a project
*/
async invalidate(projectPath: string): Promise<void> {
const key = await this.getCacheKey(projectPath);
if (!key) return;
const cacheKey = this.buildKey(key);
this.cache.delete(cacheKey);
}
/**
* Clear all cache
*/
clear(): void {
this.cache.clear();
}
/**
* Get cache statistics
*/
stats(): { size: number; keys: string[] } {
return {
size: this.cache.size,
keys: Array.from(this.cache.keys())
};
}
/**
* Build cache key from components
*/
private buildKey(key: CacheKey): string {
return `${key.projectPath.toLowerCase()}:${key.gitHead}:${key.manifestMtime}`;
}
/**
* Get cache key components for a project
*/
private async getCacheKey(projectPath: string): Promise<CacheKey | null> {
try {
// Get git HEAD
const git = simpleGit(projectPath);
let gitHead = 'no-git';
try {
const log = await git.log({ maxCount: 1 });
gitHead = log.latest?.hash || 'no-commits';
} catch (err) {
// Not a git repo or no commits
}
// Get manifest file mtime (use the first that exists)
const manifestFiles = [
'package.json',
'go.mod',
'Cargo.toml',
'pyproject.toml',
'pom.xml',
'build.gradle'
];
let manifestMtime = 0;
for (const file of manifestFiles) {
try {
const stat = await fs.stat(join(projectPath, file));
manifestMtime = stat.mtimeMs;
break;
} catch (err) {
continue;
}
}
return {
projectPath: projectPath.toLowerCase(),
gitHead,
manifestMtime
};
} catch (err) {
return null;
}
}
}
// Global cache instance
export const projectCache = new ProjectCache();
