[clangd] Cleanup FuzzyFindRequest serialization and dex benchmark

[kbobyrev]

Summary

• Due to the LLVM's JSON library changes (?), FuzzyFindRequest serialization is no longer valid since arrays are serialized as llvm::json::Array already. Hence, current implementation creates a nested array.
• YAML format is no longer the default, mention this for the benchmark.
• FIXME is no longer relevant. I ran benchmarks that showed no improvement with priority_queue years ago.

[sammccall]

Thanks!

clang-tools-extra/clangd/benchmarks/IndexBenchmark.cpp

 
 // FIXME(kbobyrev): Add index building time benchmarks.
 // FIXME(kbobyrev): Add memory consumption "benchmarks" by manually measuring
 // in-memory index size and reporting it as time.
 // FIXME(kbobyrev): Create a logger wrapper to suppress debugging info printer.
 int main(int argc, char *argv[]) {
   if (argc < 3) {
     llvm::errs() << "Usage: " << argv[0]
-                 << " global-symbol-index.yaml requests.json "
+                 << " global-symbol-index.dex requests.json "
                     "BENCHMARK_OPTIONS...\n";
     return -1;
   }
   IndexFilename = argv[1];
   RequestsFilename = argv[2];
   // Trim first two arguments of the benchmark invocation and pretend no
   // arguments were passed in the first place.
   argv[2] = argv[0];
   argv += 2;
   argc -= 2;
   ::benchmark::Initialize(&argc, argv);
   ::benchmark::RunSpecifiedBenchmarks();
 }

clang-tools-extra/clangd/index/Index.cpp

bool fromJSON(const llvm::json::Value &Parameters, FuzzyFindRequest &Request,
   if (OK && Limit <= std::numeric_limits<uint32_t>::max())
     Request.Limit = Limit;
   return OK;
 }
 
 llvm::json::Value toJSON(const FuzzyFindRequest &Request) {
   return llvm::json::Object{
       {"Query", Request.Query},
-      {"Scopes", llvm::json::Array{Request.Scopes}},
+      {"Scopes", Request.Scopes},
       {"AnyScope", Request.AnyScope},
       {"Limit", Request.Limit},
       {"RestrictForCodeCompletion", Request.RestrictForCodeCompletion},
-      {"ProximityPaths", llvm::json::Array{Request.ProximityPaths}},
-      {"PreferredTypes", llvm::json::Array{Request.PreferredTypes}},
+      {"ProximityPaths", Request.ProximityPaths},
+      {"PreferredTypes", Request.PreferredTypes},
   };
 }
 
 bool SwapIndex::fuzzyFind(const FuzzyFindRequest &R,
                           llvm::function_ref<void(const Symbol &)> CB) const {
   return snapshot()->fuzzyFind(R, CB);
 }
 void SwapIndex::lookup(const LookupRequest &R,

clang-tools-extra/clangd/index/dex/Iterator.cpp

llvm::raw_ostream &dump(llvm::raw_ostream &OS) const override {
     for (const auto &Child : Children) {
       OS << Separator << *Child;
       Separator = " ";
     }
     OS << ')';
     return OS;
   }
 
-  // FIXME(kbobyrev): Would storing Children in min-heap be faster?
   std::vector<std::unique_ptr<Iterator>> Children;
   friend Corpus; // For optimizations.
 };
 
 /// TrueIterator handles PostingLists which contain all items of the index. It
 /// stores size of the virtual posting list, and all operations are performed
 /// in O(1).
 class TrueIterator : public Iterator {