gfx/thebes/gfxSharedImageSurface.h

   1 // vim:set ts=4 sts=4 sw=4 et cin:
   2 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   3  * ***** BEGIN LICENSE BLOCK *****
   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
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  16  * The Original Code is Nokia Corporation code.
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  18  * The Initial Developer of the Original Code is Nokia Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 2005
  20  * the Initial Developer. All Rights Reserved.
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  22  * Contributor(s):
  23  *   Oleg Romashin <romaxa@gmail.com>
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  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either the GNU General Public License Version 2 or later (the "GPL"), or
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  37  * ***** END LICENSE BLOCK ***** */
  38
  39 #ifndef GFX_SHARED_IMAGESURFACE_H
  40 #define GFX_SHARED_IMAGESURFACE_H
  41
  42 #include "mozilla/ipc/Shmem.h"
  43 #include "mozilla/ipc/SharedMemory.h"
  44
  45 #include "gfxASurface.h"
  46 #include "gfxImageSurface.h"
  47
  48 class THEBES_API gfxSharedImageSurface : public gfxImageSurface {
  49     typedef mozilla::ipc::SharedMemory SharedMemory;
  50     typedef mozilla::ipc::Shmem Shmem;
  51
  52 public:
  53     virtual ~gfxSharedImageSurface();
  54
  55     /**
  56      * Return a new gfxSharedImageSurface around a shmem segment newly
  57      * allocated by this function.  |aAllocator| is the object used to
  58      * allocate the new shmem segment.  Null is returned if creating
  59      * the surface failed.
  60      *
  61      * NB: the *caller* is responsible for freeing the Shmem allocated
  62      * by this function.
  63      */
  64     template<class ShmemAllocator>
  65     static already_AddRefed<gfxSharedImageSurface>
  66     Create(ShmemAllocator* aAllocator,
  67            const gfxIntSize& aSize,
  68            gfxImageFormat aFormat,
  69            SharedMemory::SharedMemoryType aShmType = SharedMemory::TYPE_BASIC)
  70     {
  71         return Create<ShmemAllocator, false>(aAllocator, aSize, aFormat, aShmType);
  72     }
  73
  74     /**
  75      * Return a new gfxSharedImageSurface that wraps a shmem segment
  76      * already created by the Create() above.  Bad things will happen
  77      * if an attempt is made to wrap any other shmem segment.  Null is
  78      * returned if creating the surface failed.
  79      */
  80     static already_AddRefed<gfxSharedImageSurface>
  81     Open(const Shmem& aShmem);
  82
  83     template<class ShmemAllocator>
  84     static already_AddRefed<gfxSharedImageSurface>
  85     CreateUnsafe(ShmemAllocator* aAllocator,
  86                  const gfxIntSize& aSize,
  87                  gfxImageFormat aFormat,
  88                  SharedMemory::SharedMemoryType aShmType = SharedMemory::TYPE_BASIC)
  89     {
  90         return Create<ShmemAllocator, true>(aAllocator, aSize, aFormat, aShmType);
  91     }
  92
  93     Shmem& GetShmem() { return mShmem; }
  94
  95     static PRBool IsSharedImage(gfxASurface *aSurface);
  96
  97 private:
  98     gfxSharedImageSurface(const gfxIntSize&, gfxImageFormat, const Shmem&);
  99
 100     void WriteShmemInfo();
 101
 102     static size_t GetAlignedSize(const gfxIntSize&, long aStride);
 103
 104     template<class ShmemAllocator, bool Unsafe>
 105     static already_AddRefed<gfxSharedImageSurface>
 106     Create(ShmemAllocator* aAllocator,
 107            const gfxIntSize& aSize,
 108            gfxImageFormat aFormat,
 109            SharedMemory::SharedMemoryType aShmType)
 110     {
 111         if (!CheckSurfaceSize(aSize))
 112             return nsnull;
 113
 114         Shmem shmem;
 115         long stride = ComputeStride(aSize, aFormat);
 116         size_t size = GetAlignedSize(aSize, stride);
 117         if (!Unsafe) {
 118             if (!aAllocator->AllocShmem(size, aShmType, &shmem))
 119                 return nsnull;
 120         } else {
 121             if (!aAllocator->AllocUnsafeShmem(size, aShmType, &shmem))
 122                 return nsnull;
 123         }
 124
 125         nsRefPtr<gfxSharedImageSurface> s =
 126             new gfxSharedImageSurface(aSize, aFormat, shmem);
 127         if (s->CairoStatus() != 0) {
 128             aAllocator->DeallocShmem(shmem);
 129             return nsnull;
 130         }
 131         s->WriteShmemInfo();
 132         return s.forget();
 133     }
 134
 135     Shmem mShmem;
 136
 137     // Calling these is very bad, disallow it
 138     gfxSharedImageSurface(const gfxSharedImageSurface&);
 139     gfxSharedImageSurface& operator=(const gfxSharedImageSurface&);
 140 };
 141
 142 #endif /* GFX_SHARED_IMAGESURFACE_H */