loadCacheFromDisk() — mcp Function Reference

Architecture documentation for the loadCacheFromDisk() function in graph-cache.ts from the mcp codebase.

Function typescript GraphCache Persistence calls 5 called by 1

Entity Profile

GraphCache→ Persistence→ loadCacheFromDisk() — mcp Function Reference

Dependency Diagram

graph TD
  4def3ca5_c0bf_fbae_1c00_3a7385fe0264["loadCacheFromDisk()"]
  a9363f44_0cfc_87dc_a76a_4eeb9d75c684["start()"]
  a9363f44_0cfc_87dc_a76a_4eeb9d75c684 -->|calls| 4def3ca5_c0bf_fbae_1c00_3a7385fe0264
  69fc7a46_28f6_6b72_2725_66c381e53322["debug()"]
  4def3ca5_c0bf_fbae_1c00_3a7385fe0264 -->|calls| 69fc7a46_28f6_6b72_2725_66c381e53322
  e5352615_c5fb_64a2_cc5c_a248578cbc8a["warn()"]
  4def3ca5_c0bf_fbae_1c00_3a7385fe0264 -->|calls| e5352615_c5fb_64a2_cc5c_a248578cbc8a
  11d5249b_82de_e1fb_e621_e95ae1a093c5["buildIndexes()"]
  4def3ca5_c0bf_fbae_1c00_3a7385fe0264 -->|calls| 11d5249b_82de_e1fb_e621_e95ae1a093c5
  6407330b_8aa1_cc04_569a_747f6b1debfd["set()"]
  4def3ca5_c0bf_fbae_1c00_3a7385fe0264 -->|calls| 6407330b_8aa1_cc04_569a_747f6b1debfd
  90af3150_ce81_c645_faa7_5b8b9bcf5ecc["has()"]
  4def3ca5_c0bf_fbae_1c00_3a7385fe0264 -->|calls| 90af3150_ce81_c645_faa7_5b8b9bcf5ecc
  style 4def3ca5_c0bf_fbae_1c00_3a7385fe0264 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

src/cache/graph-cache.ts lines 398–458

export async function loadCacheFromDisk(
  cacheDir: string,
  cache: GraphCache
): Promise<Map<string, IndexedGraph>> {
  const repoMap = new Map<string, IndexedGraph>();

  let entries: string[];
  try {
    entries = await fs.readdir(cacheDir);
  } catch (error: any) {
    if (error.code === 'ENOENT') {
      logger.debug('Cache directory does not exist:', cacheDir);
      return repoMap;
    }
    throw error;
  }

  const jsonFiles = entries.filter(e => e.endsWith('.json'));
  logger.debug(`Found ${jsonFiles.length} cache files in ${cacheDir}`);

  for (const file of jsonFiles) {
    try {
      const filePath = join(cacheDir, file);
      const content = await fs.readFile(filePath, 'utf-8');
      const payload = JSON.parse(content);

      if (!payload.raw || !payload.repoName) {
        logger.warn(`Skipping invalid cache file: ${file}`);
        continue;
      }

      const repoName = payload.repoName as string;
      const cacheKey = `precache:${repoName}`;
      const graph = buildIndexes(payload.raw, cacheKey);

      cache.set(cacheKey, graph);
      repoMap.set(repoName.toLowerCase(), graph);

      // Index by commit hash for exact matching (e.g. "commit:abc1234")
      const commitHash = payload.commitHash as string | null;
      if (commitHash) {
        repoMap.set(`commit:${commitHash}`, graph);
      }

      // Also store common variants of the repo name for matching
      // e.g. "django" for "django__django", "astropy" for "astropy__astropy"
      const parts = repoName.toLowerCase().split(/[_\-\/]/);
      for (const part of parts) {
        if (part && part.length > 2 && !repoMap.has(part)) {
          repoMap.set(part, graph);
        }
      }

      logger.debug(`Loaded pre-computed graph for ${repoName} (commit: ${commitHash || 'unknown'}): ${graph.summary.nodeCount} nodes`);
    } catch (error: any) {
      logger.warn(`Failed to load cache file ${file}: ${error.message}`);
    }
  }

  return repoMap;
}