cc/resources/shared_bitmap.cc

   1 // Copyright 2013 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 "cc/resources/shared_bitmap.h"
   6
   7 #include "base/logging.h"
   8 #include "base/numerics/safe_math.h"
   9 #include "base/rand_util.h"
  10 #include "base/strings/string_number_conversions.h"
  11 #include "base/strings/stringprintf.h"
  12
  13 namespace cc {
  14
  15 SharedBitmap::SharedBitmap(uint8* pixels, const SharedBitmapId& id)
  16     : pixels_(pixels), id_(id) {
  17 }
  18
  19 SharedBitmap::~SharedBitmap() {
  20 }
  21
  22 // static
  23 bool SharedBitmap::SizeInBytes(const gfx::Size& size, size_t* size_in_bytes) {
  24   if (size.IsEmpty())
  25     return false;
  26   base::CheckedNumeric<size_t> s = 4;
  27   s *= size.width();
  28   s *= size.height();
  29   if (!s.IsValid())
  30     return false;
  31   *size_in_bytes = s.ValueOrDie();
  32   return true;
  33 }
  34
  35 // static
  36 size_t SharedBitmap::CheckedSizeInBytes(const gfx::Size& size) {
  37   CHECK(!size.IsEmpty());
  38   base::CheckedNumeric<size_t> s = 4;
  39   s *= size.width();
  40   s *= size.height();
  41   return s.ValueOrDie();
  42 }
  43
  44 // static
  45 size_t SharedBitmap::UncheckedSizeInBytes(const gfx::Size& size) {
  46   DCHECK(VerifySizeInBytes(size));
  47   size_t s = 4;
  48   s *= size.width();
  49   s *= size.height();
  50   return s;
  51 }
  52
  53 // static
  54 bool SharedBitmap::VerifySizeInBytes(const gfx::Size& size) {
  55   if (size.IsEmpty())
  56     return false;
  57   base::CheckedNumeric<size_t> s = 4;
  58   s *= size.width();
  59   s *= size.height();
  60   return s.IsValid();
  61 }
  62
  63 // static
  64 SharedBitmapId SharedBitmap::GenerateId() {
  65   SharedBitmapId id;
  66   // Needs cryptographically-secure random numbers.
  67   base::RandBytes(id.name, sizeof(id.name));
  68   return id;
  69 }
  70
  71 base::trace_event::MemoryAllocatorDumpGuid GetSharedBitmapGUIDForTracing(
  72     const SharedBitmapId& bitmap_id) {
  73   auto bitmap_id_hex = base::HexEncode(bitmap_id.name, sizeof(bitmap_id.name));
  74   return base::trace_event::MemoryAllocatorDumpGuid(
  75       base::StringPrintf("sharedbitmap-x-process/%s", bitmap_id_hex.c_str()));
  76 }
  77
  78 }  // namespace cc