content/renderer/render_process_impl.h

   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 CONTENT_RENDERER_RENDER_PROCESS_IMPL_H_
   6 #define CONTENT_RENDERER_RENDER_PROCESS_IMPL_H_
   7
   8 #include "base/timer/timer.h"
   9 #include "content/renderer/render_process.h"
  10
  11 class SkCanvas;
  12
  13 namespace content {
  14
  15 // Implementation of the RenderProcess interface for the regular browser.
  16 // See also MockRenderProcess which implements the active "RenderProcess" when
  17 // running under certain unit tests.
  18 class RenderProcessImpl : public RenderProcess {
  19  public:
  20   RenderProcessImpl();
  21   virtual ~RenderProcessImpl();
  22
  23   // RenderProcess implementation.
  24   virtual SkCanvas* GetDrawingCanvas(
  25       TransportDIB** memory,
  26       const gfx::Rect& rect) OVERRIDE;
  27   virtual void ReleaseTransportDIB(TransportDIB* memory) OVERRIDE;
  28   virtual void AddBindings(int bindings) OVERRIDE;
  29   virtual int GetEnabledBindings() const OVERRIDE;
  30   virtual TransportDIB* CreateTransportDIB(size_t size) OVERRIDE;
  31   virtual void FreeTransportDIB(TransportDIB*) OVERRIDE;
  32
  33  private:
  34   // Look in the shared memory cache for a suitable object to reuse.
  35   //   result: (output) the memory found
  36   //   size: the resulting memory will be >= this size, in bytes
  37   //   returns: false if a suitable DIB memory could not be found
  38   bool GetTransportDIBFromCache(TransportDIB** result, size_t size);
  39
  40   // Maybe put the given shared memory into the shared memory cache. Returns
  41   // true if the SharedMemory object was stored in the cache; otherwise, false
  42   // is returned.
  43   bool PutSharedMemInCache(TransportDIB* memory);
  44
  45   void ClearTransportDIBCache();
  46
  47   // Return the index of a free cache slot in which to install a transport DIB
  48   // of the given size. If all entries in the cache are larger than the given
  49   // size, this doesn't free any slots and returns -1.
  50   int FindFreeCacheSlot(size_t size);
  51
  52   // A very simplistic and small cache.  If an entry in this array is non-null,
  53   // then it points to a SharedMemory object that is available for reuse.
  54   TransportDIB* shared_mem_cache_[2];
  55
  56   // This DelayTimer cleans up our cache 5 seconds after the last use.
  57   base::DelayTimer<RenderProcessImpl> shared_mem_cache_cleaner_;
  58
  59   // TransportDIB sequence number
  60   uint32 transport_dib_next_sequence_number_;
  61
  62   // Bitwise-ORed set of extra bindings that have been enabled anywhere in this
  63   // process.  See BindingsPolicy for details.
  64   int enabled_bindings_;
  65
  66   DISALLOW_COPY_AND_ASSIGN(RenderProcessImpl);
  67 };
  68
  69 }  // namespace content
  70
  71 #endif  // CONTENT_RENDERER_RENDER_PROCESS_IMPL_H_