ui/surface/transport_dib_posix.cc

   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 #include "ui/surface/transport_dib.h"
   6
   7 #include <sys/stat.h>
   8 #include <unistd.h>
   9
  10 #include "base/logging.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/memory/shared_memory.h"
  13 #include "skia/ext/platform_canvas.h"
  14
  15 TransportDIB::TransportDIB()
  16     : size_(0) {
  17 }
  18
  19 TransportDIB::TransportDIB(TransportDIB::Handle dib)
  20     : shared_memory_(dib, false /* read write */),
  21       size_(0) {
  22 }
  23
  24 TransportDIB::~TransportDIB() {
  25 }
  26
  27 // static
  28 TransportDIB* TransportDIB::Create(size_t size, uint32 sequence_num) {
  29   TransportDIB* dib = new TransportDIB;
  30   if (!dib->shared_memory_.CreateAndMapAnonymous(size)) {
  31     delete dib;
  32     return NULL;
  33   }
  34
  35   dib->size_ = size;
  36   return dib;
  37 }
  38
  39 // static
  40 TransportDIB* TransportDIB::Map(Handle handle) {
  41   scoped_ptr<TransportDIB> dib(CreateWithHandle(handle));
  42   if (!dib->Map())
  43     return NULL;
  44   return dib.release();
  45 }
  46
  47 // static
  48 TransportDIB* TransportDIB::CreateWithHandle(Handle handle) {
  49   return new TransportDIB(handle);
  50 }
  51
  52 // static
  53 bool TransportDIB::is_valid_handle(Handle dib) {
  54   return base::SharedMemory::IsHandleValid(dib);
  55 }
  56
  57 skia::PlatformCanvas* TransportDIB::GetPlatformCanvas(int w, int h) {
  58   if ((!memory() && !Map()) || !VerifyCanvasSize(w, h))
  59     return NULL;
  60   return skia::CreatePlatformCanvas(w, h, true,
  61                                     reinterpret_cast<uint8_t*>(memory()),
  62                                     skia::RETURN_NULL_ON_FAILURE);
  63 }
  64
  65 bool TransportDIB::Map() {
  66   if (!is_valid_handle(shared_memory_.handle()))
  67     return false;
  68 #if defined(OS_ANDROID)
  69   if (!shared_memory_.Map(0))
  70     return false;
  71   size_ = shared_memory_.mapped_size();
  72 #else
  73   if (memory())
  74     return true;
  75
  76   int size = base::SharedMemory::GetSizeFromSharedMemoryHandle(
  77       shared_memory_.handle());
  78   if (size == -1 || !shared_memory_.Map(size))
  79     return false;
  80
  81   size_ = size;
  82 #endif
  83   return true;
  84 }
  85
  86 void* TransportDIB::memory() const {
  87   return shared_memory_.memory();
  88 }