[clangd] Fix bugs with incorrect memory estimate report

* With the current implementation, `sizeof(std::vector<Chunk>)` is added
twice to the `Dex` memory estimate which is incorrect
* `Dex` logs memory usage estimation before `BackingDataSize` is set and
hence the log report excludes size of the external `SymbolSlab` which is
coupled with `Dex` instance

Reviewed By: ioeric

Differential Revision: https://reviews.llvm.org/D52503

llvm-svn: 343117

1 files changed, 8 insertions, 2 deletions

diff --git a/clang-tools-extra/clangd/index/Serialization.cpp b/clang-tools-extra/clangd/index/Serialization.cpp
index 4f5413a7ecf..5e16137f8b2 100644
--- a/clang-tools-extra/clangd/index/Serialization.cpp
+++ b/clang-tools-extra/clangd/index/Serialization.cpp
@@ -6,8 +6,10 @@
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+
 #include "Serialization.h"
 #include "Index.h"
+#include "Logger.h"
 #include "RIFF.h"
 #include "Trace.h"
 #include "dex/Dex.h"
@@ -433,8 +435,12 @@ std::unique_ptr<SymbolIndex> loadIndex(llvm::StringRef SymbolFilename,
   }
 
   trace::Span Tracer("BuildIndex");
-  return UseDex ? dex::Dex::build(std::move(Symbols), URISchemes)
-                : MemIndex::build(std::move(Symbols), std::move(Refs));
+  auto Index = UseDex ? dex::Dex::build(std::move(Symbols), URISchemes)
+                      : MemIndex::build(std::move(Symbols), std::move(Refs));
+  vlog("Loaded {0} from {1} with estimated memory usage {2}",
+       UseDex ? "Dex" : "MemIndex", SymbolFilename,
+       Index->estimateMemoryUsage());
+  return Index;
 }
 
 } // namespace clangd