From 8c879bfca560c9f164166805510316f268b3ecd2 Mon Sep 17 00:00:00 2001
From: wp_xxyyzz <wp_xxyyzz@8e941d3f-bd1b-0410-a28a-d453659cc2b4>
Date: Fri, 25 Oct 2019 08:44:07 +0000
Subject: [PATCH] lazMapViewer: Fix memory leaks. Patch by jc99
 (https://forum.lazarus.freepascal.org/index.php/topic,47164.msg337315.html#msg337315).

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@7171 8e941d3f-bd1b-0410-a28a-d453659cc2b4
---
 components/lazmapviewer/source/mvengine.pas   | 21 +++--
 .../lazmapviewer/source/mvmapprovider.pas     | 85 +++++++++++++++++--
 2 files changed, 94 insertions(+), 12 deletions(-)

diff --git a/components/lazmapviewer/source/mvengine.pas b/components/lazmapviewer/source/mvengine.pas
index 2db24f37f..e0acf76cf 100644
--- a/components/lazmapviewer/source/mvengine.pas
+++ b/components/lazmapviewer/source/mvengine.pas
@@ -213,12 +213,12 @@ type
 
   { TEnvTile }
 
-  TEnvTile = Class
+  TEnvTile = Class(TBaseTile)
   private
     Tile: TTileId;
     Win: TMapWindow;
   public
-    constructor Create(const aTile: TTileId; const aWin: TMapWindow);
+    constructor Create(const aTile: TTileId; const aWin: TMapWindow);reintroduce;
   end;
 
 
@@ -279,17 +279,25 @@ end;
 procedure TLaunchDownloadJob.ExecuteTask(aTask: integer; FromWaiting: boolean);
 var
   iTile: integer;
+  lJob: TEventJob;
+  lTile: TEnvTile;
 begin
   iTile := aTask - 1;
-  Queue.AddUniqueJob(TEventJob.Create
+  lTile:=TEnvTile.Create(FTiles[iTile], Win);
+  lJob := TEventJob.Create
     (
       @Engine.evDownload,
-      TEnvTile.Create(FTiles[iTile], Win),
+      lTile,
       false,                                    // owns data
       Engine.GetTileName(FTiles[iTile])
-    ),
+    );
+  if not Queue.AddUniqueJob(lJob  ,
     Launcher
-  );
+  ) then
+     begin
+       FreeAndNil(lJob);
+       FreeAndNil(lTile);
+     end;
 end;
 
 function TLaunchDownloadJob.Running: boolean;
@@ -317,6 +325,7 @@ end;
 
 constructor TEnvTile.Create(const aTile: TTileId; const aWin: TMapWindow);
 begin
+  inherited Create(aWin.MapProvider);
   Tile := aTile;
   Win := aWin;
 end;
diff --git a/components/lazmapviewer/source/mvmapprovider.pas b/components/lazmapviewer/source/mvmapprovider.pas
index baab19c38..90dba9a1e 100644
--- a/components/lazmapviewer/source/mvmapprovider.pas
+++ b/components/lazmapviewer/source/mvmapprovider.pas
@@ -36,6 +36,18 @@ type
   TGetSvrStr = function (id: integer): string;
   TGetValStr = function (const Tile: TTileId): String;
 
+  TMapProvider = class;
+
+  {TBaseTile}
+  TBaseTile= class
+    FID:integer;
+    FMapProvider:TMapProvider;
+    Public
+      constructor Create(aProvider:TMapProvider);
+      destructor Destroy; override;
+      Property ID:integer read FID;
+  end;
+
   { TMapProvider }
 
   TMapProvider = class
@@ -51,12 +63,15 @@ type
       FGetZStr: Array of TGetValStr;
       FMinZoom: Array of integer;
       FMaxZoom: Array of integer;
+      FTiles:array of TBaseTile;
+      FTileHandling: TRTLCriticalSection;
       function GetLayerCount: integer;
       procedure SetLayer(AValue: integer);
-
     public
       constructor Create(AName: String);
       destructor Destroy; override;
+      function AppendTile(aTile: TBaseTile): integer;
+      procedure RemoveTile(aTile: TBaseTile);
       procedure AddURL(Url: String; NbSvr, aMinZoom, aMaxZoom: integer;
         GetSvrStr: TGetSvrStr; GetXStr: TGetValStr; GetYStr: TGetValStr;
         GetZStr: TGetValStr);
@@ -117,10 +132,27 @@ Begin
   result := IntToStr(Tile.Z + 1);
 end;
 
+{ TBaseTile }
+
+constructor TBaseTile.Create(aProvider: TMapProvider);
+begin
+  FMapProvider := aProvider;
+  if assigned(aProvider) then
+    FID:=aProvider.AppendTile(self);
+end;
+
+destructor TBaseTile.Destroy;
+begin
+  If assigned(FMapProvider) then
+    FMapProvider.RemoveTile(self);
+  FMapProvider:=nil;
+  inherited Destroy;
+end;
+
 
 { TMapProvider }
 
-function TMapProvider.getLayerCount: integer;
+function TMapProvider.GetLayerCount: integer;
 begin
   Result:=length(FUrl);
 end;
@@ -135,12 +167,15 @@ begin
   FLayer:=AValue;
 end;
 
-constructor TMapProvider.Create(aName: String);
+constructor TMapProvider.Create(AName: String);
 begin
   FName := aName;
+  InitCriticalSection(FTileHandling);
 end;
 
 destructor TMapProvider.Destroy;
+var
+  i: Integer;
 begin
   Finalize(idServer);
   Finalize(FName);
@@ -152,12 +187,50 @@ begin
   Finalize(FGetZStr);
   Finalize(FMinZoom);
   Finalize(FMaxZoom);
+  EnterCriticalSection(FTileHandling);
+  for i := high(FTiles) downto 1 do
+    try
+      freeandnil(FTiles[i]);
+    except
+      FTiles[i]:=nil;
+    end;
+  LeaveCriticalsection(FTileHandling);
+  DoneCriticalsection(FTileHandling);
   inherited;
 end;
 
-procedure TMapProvider.AddURL(Url: String; NbSvr: integer;
-  aMinZoom: integer; aMaxZoom: integer; GetSvrStr: TGetSvrStr;
-  GetXStr: TGetValStr; GetYStr: TGetValStr; GetZStr: TGetValStr);
+function TMapProvider.AppendTile(aTile: TBaseTile): integer;
+var
+  lNewID: Integer;
+begin
+  EnterCriticalSection(FTileHandling);
+  lNewID :=high(FTiles)+1;
+  setlength(FTiles,lNewID+1);
+  FTiles[lNewID]:=aTile;
+  LeaveCriticalsection(FTileHandling);
+  result := lNewID;
+end;
+
+procedure TMapProvider.RemoveTile(aTile: TBaseTile);
+var
+  lID, lMaxTile: Integer;
+begin
+  if (atile.ID <= high(FTiles)) and (atile.ID>0) and (FTiles[aTile.ID]=aTile) then
+    begin
+      EnterCriticalSection(FTileHandling);
+      lID := aTile.ID;
+      lMaxTile :=High(FTiles);
+      aTile.FID := -1;
+      FTiles[lID] := FTiles[lMaxTile];
+      FTiles[lID].FID := lID;
+      setlength(FTiles,lMaxTile);
+      LeaveCriticalsection(FTileHandling);
+    end;
+end;
+
+procedure TMapProvider.AddURL(Url: String; NbSvr, aMinZoom, aMaxZoom: integer;
+  GetSvrStr: TGetSvrStr; GetXStr: TGetValStr; GetYStr: TGetValStr;
+  GetZStr: TGetValStr);
 var
   nb: integer;
 begin