T826-026 Workspace_Symbols Request

Do not process too small pattern because this produces a huge
 response that is useless and costs a while.

Corrections for requests cancelling

Author: ogorodnik

source/ada/lsp-ada_handlers.adb

@@ -3751,14 +3751,17 @@ package body LSP.Ada_Handlers is
       Request : LSP.Messages.Server_Requests.Workspace_Symbols_Request)
       return LSP.Messages.Server_Responses.Symbol_Response
    is
+      use type LSP.Messages.Search_Kind;
+      use type VSS.Strings.Character_Count;
+
       procedure On_Inaccessible_Name
         (File : GNATCOLL.VFS.Virtual_File;
          Name : Libadalang.Analysis.Defining_Name;
          Stop : in out Boolean);
 
       Names : LSP.Ada_Completions.Completion_Maps.Map;
 
-      package Canceled is new LSP.Generic_Cancel_Check (Request, 127);
+      package Canceled is new LSP.Generic_Cancel_Check (Request'Access, 127);
 
       procedure Write_Symbols is
         new LSP.Ada_Completions.Generic_Write_Symbols
@@ -3803,6 +3806,16 @@ package body LSP.Ada_Handlers is
         (Is_Error => False);
 
    begin
+      if Pattern.Get_Kind /= LSP.Messages.Start_Word_Text
+        and then Pattern.Get_Canonical_Pattern.Character_Length < 2
+      then
+         --  Do not process too small pattern because
+         --  this produces a huge response that is useless
+         --  and costs a while.
+
+         return Response;
+      end if;
+
       for Context of Self.Contexts.Each_Context loop
          Context.Get_Any_Symbol
            (Pattern     => Pattern,

source/server/lsp-generic_cancel_check.ads

@@ -23,14 +23,14 @@
 with LSP.Messages.Server_Requests;
 
 generic
-   Request : LSP.Messages.Server_Requests.Server_Request'Class;
+   Request : access constant LSP.Messages.Server_Requests.Server_Request'Class;
    --  A request to check cancelation
+
    Max_Skip_Count : Natural;
    --  How much checks to skip before make a real atomic flag check
 
 package LSP.Generic_Cancel_Check is
 
-   function Has_Been_Canceled return Boolean
-     with Inline;
+   function Has_Been_Canceled return Boolean with Inline;
 
 end LSP.Generic_Cancel_Check;

testsuite/ada_lsp/workspace_symbol/test.json

@@ -71,30 +71,13 @@
                 "id":"wsSymbol",
                 "method":"workspace/symbol",
                 "params":{
-                    "query":""
+                    "query":"Test"
                 }
             },
             "sortReply": {"result":"name"},
             "wait":[{
                 "id": "wsSymbol",
                 "result": [
-                    {
-                        "name": "Main",
-                        "kind": 12,
-                        "location": {
-                            "uri": "$URI{main.adb}",
-                            "range": {
-                                "start": {
-                                    "line": 0,
-                                    "character": 10
-                                },
-                                "end": {
-                                    "line": 0,
-                                    "character": 14
-                                }
-                            }
-                        }
-                    },
                     {
                         "name": "Test1",
                         "kind": 12,