loadCacheFromDisk() — mcp Function Reference

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

Function typescript GraphCache DiskPersistence calls 5 called by 1

Entity Profile

GraphCache→ DiskPersistence→ loadCacheFromDisk() — mcp Function Reference

Dependency Diagram

graph TD
  f528cae6_71d3_4b84_026d_d4778648e9c8["loadCacheFromDisk()"]
  08ca54b2_22bc_134f_e028_7c18da8dca8a["start()"]
  08ca54b2_22bc_134f_e028_7c18da8dca8a -->|calls| f528cae6_71d3_4b84_026d_d4778648e9c8
  b8971bfc_ba3c_23a9_1f17_5d613ac67105["debug()"]
  f528cae6_71d3_4b84_026d_d4778648e9c8 -->|calls| b8971bfc_ba3c_23a9_1f17_5d613ac67105
  dfe11f52_4dd3_db89_9717_941d05bae091["warn()"]
  f528cae6_71d3_4b84_026d_d4778648e9c8 -->|calls| dfe11f52_4dd3_db89_9717_941d05bae091
  2f679171_fd3f_3cd5_48b2_587cc9ec01fd["buildIndexes()"]
  f528cae6_71d3_4b84_026d_d4778648e9c8 -->|calls| 2f679171_fd3f_3cd5_48b2_587cc9ec01fd
  b965d3cf_dacd_81fc_77e7_dbe9bdef8bbc["set()"]
  f528cae6_71d3_4b84_026d_d4778648e9c8 -->|calls| b965d3cf_dacd_81fc_77e7_dbe9bdef8bbc
  c652ed9f_2901_0635_2a5b_fc305e9cd6c1["has()"]
  f528cae6_71d3_4b84_026d_d4778648e9c8 -->|calls| c652ed9f_2901_0635_2a5b_fc305e9cd6c1
  style f528cae6_71d3_4b84_026d_d4778648e9c8 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;
}