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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef UI_GFX_X_X11_ATOM_CACHE_H_
6 #define UI_GFX_X_X11_ATOM_CACHE_H_
7 
8 #include <map>
9 #include <string>
10 
11 #include "base/basictypes.h"
12 #include "ui/gfx/gfx_export.h"
13 
14 typedef unsigned long Atom;
15 typedef struct _XDisplay XDisplay;
16 
17 namespace ui {
18 
19 // Pre-caches all Atoms on first use to minimize roundtrips to the X11
20 // server. By default, GetAtom() will CHECK() that atoms accessed through
21 // GetAtom() were passed to the constructor, but this behaviour can be changed
22 // with allow_uncached_atoms().
23 class GFX_EXPORT X11AtomCache {
24  public:
25   // Preinterns the NULL terminated list of string |to_cache_ on |xdisplay|.
26   X11AtomCache(XDisplay* xdisplay, const char** to_cache);
27   ~X11AtomCache();
28 
29   // Returns the pre-interned Atom without having to go to the x server.
30   Atom GetAtom(const char*) const;
31 
32   // When an Atom isn't in the list of items we've cached, we should look it
33   // up, cache it locally, and then return the result.
allow_uncached_atoms()34   void allow_uncached_atoms() { uncached_atoms_allowed_ = true; }
35 
36  private:
37   XDisplay* xdisplay_;
38 
39   bool uncached_atoms_allowed_;
40 
41   mutable std::map<std::string, Atom> cached_atoms_;
42 
43   DISALLOW_COPY_AND_ASSIGN(X11AtomCache);
44 };
45 
46 }  // namespace ui
47 
48 #endif  // UI_GFX_X_X11_ATOM_CACHE_H_
49