Conditionally allow reindex on didChange

src/config.h

@@ -212,6 +212,10 @@ struct Config {
     bool sort = true;
   } workspaceSymbol;
 
+  // Allow indexing on textDocument/didChange.
+  // May be too slow for big projects, so it is off by default.
+  bool enableIndexOnDidChange = false;
+
   struct Xref {
     // If true, |Location[]| response will include lexical container.
     bool container = false;
@@ -273,6 +277,8 @@ MAKE_REFLECT_STRUCT(Config,
                     workspaceSymbol,
                     xref,
                     
+                    enableIndexOnDidChange,
+
                     dumpAST);
 
 // Expected client version. We show an error if this doesn't match.

src/messages/text_document_did_change.cc

@@ -1,6 +1,11 @@
+#include "cache_manager.h"
 #include "clang_complete.h"
 #include "message_handler.h"
+#include "project.h"
 #include "working_files.h"
+#include "queue_manager.h"
+
+#include <loguru/loguru.hpp>
 
 namespace {
 struct Ipc_TextDocumentDidChange
@@ -17,6 +22,18 @@ struct TextDocumentDidChangeHandler
   void Run(Ipc_TextDocumentDidChange* request) override {
     std::string path = request->params.textDocument.uri.GetPath();
     working_files->OnChange(request->params);
+    if (config->enableIndexOnDidChange) {
+      optional<std::string> content = ReadContent(path);
+      if (!content) {
+        LOG_S(ERROR) << "Unable to read file content after saving " << path;
+      } else {
+        Project::Entry entry = project->FindCompilationEntryForFile(path);
+        QueueManager::instance()->index_request.PushBack(
+            Index_Request(entry.filename, entry.args, true /*is_interactive*/,
+                          *content, ICacheManager::Make(config)),
+            true);
+      }
+    }
     clang_complete->NotifyEdit(path);
     clang_complete->DiagnosticsUpdate(
         std::monostate(),

src/messages/text_document_did_save.cc

@@ -34,7 +34,8 @@ struct TextDocumentDidSaveHandler
     // Send out an index request, and copy the current buffer state so we
     // can update the cached index contents when the index is done.
     //
-    // We also do not index if there is already an index request.
+    // We also do not index if there is already an index request or if
+    // the client requested indexing on didChange instead.
     //
     // TODO: Cancel outgoing index request. Might be tricky to make
     //       efficient since we have to cancel.
@@ -44,6 +45,7 @@ struct TextDocumentDidSaveHandler
     //      mutex and check to see if we should skip the current request.
     //      if so, ignore that index response.
     // TODO: send as priority request
+    if (!config->enableIndexOnDidChange) {
       optional<std::string> content = ReadContent(path);
       if (!content) {
         LOG_S(ERROR) << "Unable to read file content after saving " << path;
@@ -54,6 +56,7 @@ struct TextDocumentDidSaveHandler
                           *content, ICacheManager::Make(config)),
             true);
       }
+    }
 
     clang_complete->NotifySave(path);
   }