Method cacheKey

gopls/internal/cache/analysis.go:620–648

cacheKey returns a cache key that is a cryptographic digest of the all the values that might affect type checking and analysis: the analyzer names, package metadata, names and contents of compiled Go files, and vdeps (successor) information (export data and facts).

()

// compiled Go files, and vdeps (successor) information
// (export data and facts).
func (an *analysisNode) cacheKey() file.Hash {
	hasher := sha256.New()

	// In principle, a key must be the hash of an
	// unambiguous encoding of all the relevant data.
	// If it's ambiguous, we risk collisions.

	// analyzers
	fmt.Fprintf(hasher, "analyzers: %d\n", len(an.analyzers))
	for _, a := range an.analyzers {
		fmt.Fprintln(hasher, a.Name)
	}

	// type checked package
	fmt.Fprintf(hasher, "package: %s\n", an.ph.key)

	// metadata errors: used for 'compiles' field
	fmt.Fprintf(hasher, "errors: %d", len(an.ph.mp.Errors))

	// vdeps, in PackageID order
	for _, vdep := range moremaps.Sorted(an.succs) {
		hash := vdep.summaryHash()
		hasher.Write(hash[:])
	}

	var hash file.Hash
	hasher.Sum(hash[:0])
	return hash
}

// run implements the cache-miss case.
// This function does not access the snapshot.